Quest 10(4)

Science for South Africa ISSN 1729-830X

Getting climate-smart with urban agriculture Stopping aircraft When care becomes from exploding obsession

Volume 10 | Number 4 | 2014

TB and diabetes: an unexpected link The Taung Child The ever-changing universe Acad e my O f Sci e n ce O f South Afri ca

Anti-cyber bullying software: Practical research at its finest When it come to innovation, being able to commercially sell an invention is the ultimate goal of practical research. This is called technology transfer – the mark of successful research inventions. When a researcher can release his or her research to the public, it allows him or her to actively contribute to the promotion of society in one way or another. Khutso Bapela, a BSc Computer Science graduate from the University of Pretoria, whose company resides at the University’s research partner, the Innovation Hub, is one such inventor.

The Motswadi system Bapela has successfully developed an anti-cyber bullying application (app) aimed at helping parents of young children in all South African communities to monitor their children’s online activities to prevent them from becoming victims of cyber bullying. The Motswadi system (meaning “parent” system) is a specialised SIM card for modems and cellphones that is linked to a downloadable app. The system enables parents to regulate the online activities of children aged 9 to 15 in the overwhelming and ever-expanding world of the internet and social media.

While studying towards his Computer Science degree, Bapela started to play with the idea of developing a system that could not only prove commercially viable, but also improve the lives of South African communities at grassroots level. In today’s digital world, all facets of social life have moved into the digital space in one way or another. While this shift is good in terms of education, business and technology, it has made young children vulnerable on a whole new level. Cyber bullying, as well as access to masses of inappropriate and harmful information, poses a serious threat to the wellbeing of young children both in South Africa and the rest of the world.

The Motswadi system uses an app algorithm that wirelessly picks up the specialised SIM card in a child’s cellphone or modem.

The app enables parents to set up an internet profile for each of their children that is tailored to each particular child’s needs and vulnerabilities. Standard age group settings determine the level of protection that the system applies to a child’s profile. Parents can also customise these settings. The app can set time limits for things like internet use and WhatsApp messaging, block searches for certain keywords, blacklist and re-allow specific websites, block selected apps and implement a web schedule. The system also allows parents to monitor their child’s internet activities, SMSs, Facebook account notifications and the child’s location (which is updated every 15 minutes).

Khutso Bapela is a BSc Computer Science graduate of the University of Pretoria. He has established his own company at the Innovation Hub.

The way forward for the Motswadi system The Motswadi system has been awarded a South African provisional patent through the Innovation Hub’s patent package.

A patent gives an inventor the right to make his or her invention public without fear that it will be copied by someone else. This patent provides Bapela with a further 12 months to safely conduct further research and development to perfect the system. Bapela intends to use this time to improve the system’s functionality and the app’s interface. Bapela intends to license the Motswadi system to mobile network providers in South Africa and other countries on the continent. He has already entered into conversations with leading South African network providers to commercialise the system on home soil.

As a young inventor, Bapela serves as an inspirational role model for prospective researchers and inventors. He is living proof that there is no minimum age limit to innovative thinking and a commitment to improving society.

Universiteit van Pretoria • University of Pretoria • Yunibesithi ya Pretoria Privaatsak • Private Bag • Mokotla wa Posa X 20 • Hatfield • 0028 Suid-Afrika • South Africa • Afrika Borwa Tel: +27 12 420 2164/3637 • Faks • Fax • Fekse: +27 12 362 5000

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ontents Volume 10 | Number 4 | 2014

Cover Stories 3 Climate-smart urban agriculture in eThekwini

Jacob Knegtel and Sershen Naidoo look at ways that urban farmers can outsmart climate change

6 Aerial explosions

Genevieve Langdon tells all

8 Obsessive-compulsive disorder: when once is never enough

Christine Lochner and Elsie Breet explain how care can become compulsion

10 Tuberculosis (TB) control in an era of emerging non-communicable diseases

Tolu Oni looks at the interaction between tuberculosis and diabetes

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12 The transient universe

Patrick Woudt and Vanessa McBride look at the search for ‘new’ objects in the universe

18 The Taung Child: Casting new light on human evolution

Quest looks at how the latest research is shaping the way we think about our evolution

Features

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16 Earlier Stone Age Artefacts found in Northern Cape

Quest looks at the link between archaeological research and heritage conservation

20 Capacity development in aquatic biodiversity

Penny Haworth shows how SAIAB is training the next generation of aquatic scientists

28 It all started with diamonds

Lucy Stone describes the importance of the largest ‘microscope’ in Europe

38 When seeing is not believing

Lize Joubert shows us how insects can look completely different – or nearly the same – in different stages of their life cycle

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Regulars

News 26 Radio telescopes unravel mystery of nova gamma rays 33 Aardwolves select their termite diet carefully 34 Mass vaccination can keep this neglected disease under control 36 Earliest modern human sequenced 37 University of Pretoria focus on research to aid in the rhino’s fight for survival 41 New insight into human origins 42 New solar car ready to defend title 47 Whistling a different tune

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44 Books 46 Subscription 48 Back page science • Mathematics puzzle

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Science for South AfricA iSSn 1729-830X

Getting climate-smart with urban agriculture Stopping aircraft When care becomes from exploding obsession

Volume 10 | Number 4 | 2014

TB and diabetes: an unexpected link The Taung Child The ever-changing universe AcAd e my o f Sci e n ce o f South Afri cA

Images: Wits University, Wikimedia Commons, NASA, Jacob Knegtel

Editor Dr Bridget Farham Editorial Board Roseanne Diab (EO: ASSAf) (Chair) John Butler-Adam (South African Journal of Science) Anusuya Chinsamy-Turan (University of Cape Town) Neil Eddy (Wynberg Boys High School) George Ellis (University of Cape Town) Kevin Govender (SAAO) Himla Soodyall (University of the Witwatersrand) Penny Vinjevold (Western Cape Education Department) Correspondence and enquiries The Editor PO Box 663, Noordhoek 7979 Tel.: (021) 789 2331 Fax: 0866 718022 e-mail: ugqirha@iafrica.com Advertising enquiries Barbara Spence Avenue Advertising PO Box 71308 Bryanston 2021 Tel.: (011) 463 7940 Fax: (011) 463 7939 Cell: 082 881 3454 e-mail: barbara@avenue.co.za Subscription enquiries and back issues Phathu Nemushungwa Tel.: (012) 349 6624 e-mail: phathu@assaf.org.za Copyright © 2014 Academy of Science of South Africa

Published by the Academy of Science of South Africa (ASSAf) PO Box 72135, Lynnwood Ridge 0040, South Africa

Permissions Fax: 0866 718022 e-mail: ugqirha@iafrica.com Subscription rates (4 issues and postage) (For other countries, see subscription form) Individuals/Institutions – R100.00 Students/schoolgoers – R50.00

Walking in space a life in science

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suspect that most of my readers will be far too young to remember the Apollo 11 moon landing on 21 July 1969. But I am old enough to vividly remember getting up early in the morning to watch the hazy black and white TV footage of Neil Armstrong taking humankind’s first steps on the Moon. And was I excited by this – probably one of many events that inspired a love of science and the careers I have subsequently followed.

At the same time that I was watching my black and white TV in a small village in Surrey, England, a young man called Chris Hadfield was watching the event from a farm in Ontario, Canada. And he became an astronaut – and because of his personality probably one of the best-known astronauts after Neil Armstrong and Buzz Aldrin – to date the only two people to walk on the Moon. Chris Hadfield became the first Canadian to walk in space. In his autobiography, Chris Hadfield talks of how the Apollo Moon landing inspired his interest in science, which led him to become an astronaut. Chris Hadfield’s route into space was through the Canadian armed forces, where he got an engineering degree through the Royal Military College. As is the case for many astronauts, he started his career as a test pilot for the Canadian air force, and gained a master’s degree in aviation systems at the same time. He was accepted into the Canadian astronaut programme in 1992 and started flying space missions in 1995. But it was from 2013 that he started to become well known to the public, when he took over as commander of the International Space Station (ISS) as part of Expedition 35. He was responsible for a crew of five astronauts and helped to run dozens of experiments looking at the impact of low gravity on human biology.

However, what he is best known for by most people is the wonderful way in which he chronicled life aboard the ISS – using Facebook, Twitter and Tumbir to publicise life as an astronaut and the wonders of space and the science of low-gravity environments – and showing that he plays the guitar and sings quite well too!

Now retired, he still regularly posts updates focusing on science and life in general in various social media sites. For example, did you ever think about being able to take hand-held photographs with absolutely no tremor in a zero-gravity environment? He regularly posts interesting snippets of scientific information on his Facebook page.

The latest is on the different ways that birds, bugs and people breathe. He has written a best-selling book An Astronaut’s Guide to Life and is devoting his retirement to ensuring that everyone becomes as enthusiatic about science as he is.

There are many ways to have a life in science – not all of them as exciting as Chris Hadfield’s has been – but understanding how the world around us works shows just how exciting science and nature are. Reach for your dreams and explore.

Design and layout Creating Ripples Graphic Design Illustrations James Whitelaw Printing Seriti Printing Pty Ltd

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Bridget Farham Editor – QUEST: Science for South Africa All material is strictly copyright and all rights are reserved. Reproduction without permission is forbidden.

Every care is taken in compiling the contents of this publication, but we assume no responsibility for effects arising therefrom. The views expressed in this magazine are not necessarily those of the publisher.

A household urban agriculture plot in Cato Manor with vegetables and banana trees planted together – a practice known as companion planting. Image: Jacob Knegtel

Climate-smart urban agriculture in eThekwini Jacob Knegtel and Sershen Naidoo ask if urban farmers in eThekwini can outsmart climate change.

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wenty years into democracy and South Africa is still facing serious challenges to development.

Climate change represents one of these challenges.

In eThekwini, along the east-coast of South Africa, urban agriculture could, however, be a climatesmart and eco-friendly way for poor people to farm urban environments subject to the effects of climate change and globalisation. This article describes the findings of a recent study which investigated whether climate-smart urban agriculture can improve peoples’ livelihoods in the lowincome area of Cato Manor, in eThekwini.

region will probably experience an increase of 1.5 – 2.5°C in average annual temperature by 2045 – 2056. This is likely to be accompanied by lower agricultural production, increased soil erosion from flooding and damage to not only trees and animals in the greater municipal area, but also to roads and living areas. All the city’s residents are likely to feel the effects of climate change in some way but the urban poor, women and children particularly, are likely to be most affected.

Urban agriculture and the urban poor Climate change is not the only problem facing poor people living in urban areas in eThekwini. After more than a century

Climate change in urban South Africa South Africa has encountered a new obstacle before reaching the golden end of Nelson Mandela’s rainbow and this is climate change. On a global scale, climate change is hitting Africa the hardest and South Africa is no exception. The country is currently one of the major CO2 emitters on the continent, mainly because of its massive coal-based energy plants. This capacity to produce large amounts of energy has allowed South Africa to become one the fastest growing economies in the world but also fuelled climate change and has had a negative impact on natural environments. eThekwini Rising temperatures and altered rainfall patterns are just some of the impacts of climate change that affect cities such as the eThekwini Metropolitan Municipality. This coastal metropolis, which is one of the 11 districts of KwaZulu-Natal province, was created in 2000 and includes the city of Durban and surrounding towns. It is the largest port city on Africa’s eastern coastline and is home to 3.5 million people. The

Formal housing (front) and informal housing (back) in Cato Manor, eThekwini.

Image: Jacob Knegtel

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A communal urban farm plot in Cato Manor, eThekwini. Image: Jacob Knegtel

of racial segregation, almost 23% of its citizens are currently living below the National Poverty Line, which means their income is below R620 a month. Many of these people have settled in townships on the outskirts of the city or in informal settlements in and around the city, such as Cato Manor.

Limited living space, no or limited access to clean water, sanitation and electricity, and poor soil quality and bad roads, make it difficult for most of these people to improve their livelihood. Despite these conditions many poor residents of Cato Manor and other districts in eThekwini continue to practise urban agriculture (UA). Urban agriculture involves activities that produce, process and market food and fuel, largely in response to the daily demand of consumers within a town, city or metropolis, on land and/or water dispersed throughout the urban and peri-urban area.

In developing countries like South Africa, UA is common in low-income urban areas and there is increasing evidence that it can enable communities and households within rapidly growing cities to overcome the negative effects of rapid growth, contribute to sustainable development and, more recently, cope with and/or adapt to the direct and indirect impacts of climate change.

UA practices can vary greatly in space and time and there appears to be no universal approach or combination of approaches. In Cato Manor for example, it is practised at the household and communal levels and popular crops include maize, leafy vegetables, peppers and chillies, root vegetables and fruit trees.

In eThekwini UA is widespread, but is mainly practised by unemployed black women, older than 50, with a low income and little or no education. They use UA as poverty-fighting tool by growing food crops that supplement their household food needs. Surplus produce is also sold in some cases to generate a small income. Some residents join forces to farm together on communal farms, which increases the yield and so their potential to generate money. Urban agriculture or ‘farming activity within the inner-city environment’ is therefore one of the strategies that could improve or sustain the livelihoods of the urban poor in a changing climate.

Climate-smart urban agriculture With climate change becoming an increasingly serious problem there is a growing need to develop strategies to generate food and energy with limited resources and lower environmental impacts. UA is potentially one of these strategies since it involves applying intensive production methods, and using and reusing natural resources and urban wastes to support a diversity of crops and livestock. Sustainable farming techniques and natural resource conservation as part of UA represent a climate-smart 4

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A compost heap for climate-smart urban agricultural use in Cato Manor, eThekwini. Image: Jacob Knegtel

strategy for poor people and future generations to sustain their livelihoods and the environment around them. And this is a potentially realistic way to cope with climate change.

Climate-smart urban agriculture involves farming practices that sustainably increase productivity, resilience (adaptation), reduce/remove greenhouse gases (mitigation), and help to achieve national food security and development goals.

Although this strategy is becoming more and more popular among urban and rural farmers worldwide, farmers in cities like eThekwini, and in the rest of Africa, still lack basic knowledge of the various climate-smart agricultural methods, for example rainwater harvesting, intercropping with legumes, crop rotation, terraces, drip irrigation and production of energy plants. These methods could potentially benefit many urban farmers in cities like eThekwini but it is uncertain how popular, necessary and implementable climate-smart agricultural practices are in areas like Cato Manor. These uncertainties were investigated in this study and some of our findings are discussed below. eThekwini Municipality’s green thumb Over the last two decades, the eThekwini Municipality, like other municipalities across the country, has invested many resources into green and eco-friendly programmes.

For example, in 2004 eThekwini launched the Municipal Climate Protection Programme (MCPP) which is responsible for monitoring and responding to climate change challenges within the municipality. A major focus of the programme is to develop strategies to assist poor people to adapt to climate change.

The programme incorporates a number of activities designed to assist urban farmers, e.g. community-led installation of barrels and gutters to collect rainwater; training in composting and permaculture techniques; and construction of roof gardens. The intention here is to educate and equip farmers to use proven climate-smart agricultural techniques to sustain their farms. Apart from this programme, the municipality also implemented an Agroecology Programme, which looks at how farming can be used to alleviate poverty and unemployment.

One of the outcomes of this programme is the creation of six large-scale farms outside the city centre for poor people to source seeds and learn eco-friendly and climate-smart farming techniques in a farm setting.

However, evidence of climate-smart UA practices are far more common in peri-urban and rural as opposed to urban poor communities. In the section below we explore possible reasons for the relatively lower uptake of climate-smart urban agriculture in poor urban communities like Cato Manor.

What urban farmers know Cato Manor is an established residential area close to the city centre, dominated by poor African communities, many of which engage in UA. Small household gardens are very popular but there are also many community gardens where farmers work together. Discussions with urban farmers indicated that they engage in UA mainly to feed their families and/or earn some money. Many of the farmers don’t know about climate change. However, after explaining to them what climate change involved and its effects, they started to share their stories on how droughts were becoming more frequent and rainfall patterns were changing over the last few years. One of the elderly female farmers said: ‘These droughts make farming for me very difficult and I still have to feed five children. I’m finding it hard to still like farming because of these changes’.

It was however, encouraging to observe that a few farmers in Cato Manor were already using climate-smart farming techniques, such as composting, but they were not aware that these techniques were climate-smart. Further discussion revealed that this is possibly because these techniques were taught to them (in workshops, for example) without linking them to climate change and climate-smart farming. This suggests that urban farmers possibly do not adopt or use climate-smart farming techniques on a large scale because they do not fully understand that these techniques could help them sustain their farms and the natural environment under changing climatic conditions. Once the farmers in Cato Manor were made aware of the possible effects of climate change and the potential benefits of climatesmart farming, almost all of them wanted to adopt these techniques.

What urban farmers need to know A major finding of the study was that urban farmers felt that the municipality needed to do more in terms of educating them about, and helping them implement, climate-smart urban agricultural techniques. In contrast, a survey involving a large number of professionals from the municipality, civil society and higher education whose work is in some way related to UA in eThekwini revealed that the vast majority of them were aware of climate change and climate-smart agricultural techniques and believed that climate-smart agriculture was practised on a relatively wide scale in eThekwini.

There seemed to be a serious mismatch in the understanding of UA between the professionals and the farmers in eThekwini. For example, the professionals thought that ‘making money’ is the most important purpose of UA while the Cato Manor farmers saw UA as a means of providing food for their families. Also, the farmers said that ‘lack of training’, ‘low farming skills and knowledge’ and ‘not a lot of farm land available’ were their major challenges, while the professionals did not realise that any of these factors were a major issue. Finally, most of the professionals indicated that climate change is not a problem for farmers in the city, mainly because these farmers are adapting to climate change, while the farmers said that climate change is definitely affecting their productivity and that they do not

A household rainwater harvesting system (green tanks) for climate-smart urban agricultural use in Cato Manor, eThekwini. Image: Jacob Knegtel

know how to adapt to these climatic changes. As one of the farmers said, ‘I know about seasonal planting, but I’ve never received any training about climate change’.

This suggests that improving the uptake of climate-smart urban agriculture in poor communities like Cato Manor will require improved public awareness around climate change and increased training of urban farmers in climatesmart agriculture techniques. The training should also be designed to help farmers identify which climate-smart urban agriculture techniques would be most effective in their gardens and most achievable with their resources.

Planting for the future Educating the poor about climate change and the value of climate-smart agriculture is key to reducing their vulnerability to climate change. Climate-smart urban agricultural practices can help to mitigate the effects of climate change and ensure the food security of the increasing number of poor urban people in cities like eThekwini. However, it must be noted that the success of specific climate-smart agricultural techniques depends on the location of the farm and even more importantly, the knowledge of the farmer. To extract the full benefits of climate-smart agriculture within urban areas such as Cato Manor we need to improve urban farmers’ knowledge of climate change and sustainability. q Dr Sershen Naidoo is a lecturer in Plant Ecophysiology at the University of KwaZulu-Natal (UKZN). He has a BSc in Biology, a BSc Honours in Plant Physiology, an MSc in Seed Biology and a PhD in Cryobiology and Plant Physiology from UKZN. He is currently the co-chair of the South African Young Academy of Sciences and champions a number of projects related to food and water security on their behalf. His involvement in numerous community-based urban agriculture projects and ongoing commitment to the NGO sector across Africa have seen him earn numerous accolades (including a Clinton Democracy Fellowship). He is actively involved in research projects ranging from Plant Germplasm Conservation, Plant Responses to Climate Change, Water and Air Pollution, Urban Conservation/ Ecology/ Greening, Renewable Energy, and supervises/co-supervises over 15 postgraduate students.

Jacob Knegtel is an MSc student in International Development Studies at the University of Utrecht and MA Heritage Studies at the University of Amsterdam. His bachelor’s degree programme was Human Geography and Planning. He is currently working at Both ENDS, an NGO based in Amsterdam which focuses on the relationship between climate change and sustainable development.

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Setting up for an explosion test at the BISRU Lab. Image: Genevieve Langdon

Aerial explosions Genevieve Langdon explains all about explosions, aircraft materials and composite materials

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omposite materials are made from at least two different materials that have significantly different properties. When these materials are combined into the composite, a new material with different

What is an explosion?

Large-scale explosions.

Image: Wikimedia Commons

An explosion is quick release of a large amount of energy in a very short time. There are three main types – mechanical, chemical or nuclear.

Nuclear explosions don’t really affect aircraft safety but mechanical and chemical explosions could be a risk. One possible cause of a mechanical type of explosion is the rupture of a pressurised vessel. When an aircraft flies at altitude, the inside of the aircraft has to be pressurised and if some part of the aircraft were breeched, rapid depressurisation would occur. Chemical explosions can have many causes, such as vapour cloud explosions and the detonation of explosives. Vapour cloud explosions are usually accidental and can be prevented by carefully designing the fuel systems. Explosive detonations are the ones that make the headlines – as a result of deliberate terrorist attacks. A lot of effort goes into preventing explosives from entering aircraft by employing sophisticated detection systems for the explosives, trying to identify potential terrorists before they act and by increasing airport security. Prevention is definitely the best option, but it is still necessary to understand the effects of explosions on materials used in the aircraft industry just in case the worst should happen.

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characteristics to the individual parts is produced. Often, the composite has better properties than the sum of the individual materials. The individual constituents are still identifiable and distinct within the new composite.

Everyday examples of composites are concrete and fibrereinforced plastics.

Traditionally, most aircraft have been manufactured from high-performance aluminium alloys. Now, composite materials are being used more frequently. For example, fibre-reinforced plastics make up the majority of the fuselage sections of the new Airbus A380 and Boeing 787 aircraft. Sometimes the composites are used on their own (like carbon fibre-reinforced epoxy on the Boeing) or are stacked in layers between thin metal sheets into a hybrid structural material known as a fibre-metal laminate (such as GLARE© used in the Airbus).

Why are composites being used?

The advantages of composite materials when compared with metals such as aluminium alloy, are: n Lightweight (a big advantage in aircraft design) n Better fatigue resistance n Life cycle cost savings, meaning the plane is cheaper to maintain or fly over the whole course of its life n Improved fuel efficiency (the aircraft will be kinder to the environment if it is more fuel efficient) n Improved impact properties (in some cases) n The ability to tailor the properties of the composite to suit the precise application by changing the fibre directions.

The various different ways in which composite materials can break down and fail under the stress of an explosion.

Image: Genevieve Langdon

Onboard explosions One of the risks faced by aircraft is an onboard explosion, either caused by rapid depressurisation at altitude or from a deliberate act of terrorism. The effects of explosions are often disastrous, particularly in the confined space on board aircraft because the energy is trapped in a small space and is multiplied many times more than it would be if the explosion took place in free air. Thankfully, explosions onboard aeroplanes are rare, but the potential danger has been impressed on people’s minds since the devastating 9/11 attacks in the US. This is why we need to understand the response of composites to conditions associated with explosion loading, even if the events are unlikely to happen.

The research At the Blast Impact and Survivability Research Unit (BISRU) we have been performing small-scale explosion tests to understand how fibre-reinforced plastics react to explosions. We detonate small quantities of plastic explosive to test materials under realistic conditions.

All materials absorb some of the explosion energy by deforming or breaking in some way. There are many possible ways for the fibre-reinforced plastic to absorb the energy from an explosion as the different parts inside the composite can move and fail in different ways. Some of the possible ways to fail the composite materials are shown in the diagrams and photographs seen in this article.

Alongside the experiments, we model the behaviour of the materials using computer software. This helps us to try and predict the loading from the explosion and how the composites will break during the explosive testing. This allows us to evaluate different composite materials and panel designs, and work out where the structures might fail in a real explosion.

Some of our recent work has shown that composites are better able to contain explosion loading that is uniformly distributed, which is more likely to happen if the explosive is not close to the composites when it is detonated. The failure types in composites are complex. The type of failure and the ability of a composite not to completely rupture under explosions loading depends upon many factors, including the materials, panel geometry, overall panel thickness and the exact way the individual materials are stacked together inside the composite. Woven composites (when the fibres inside are interweaved and not just overlaid) appear to be more blast resistant. Coatings and filler materials could be important and will be researched in the future. q Professor Genevieve Langdon is currently a Professor and Deputy Head of the Mechanical Engineering Department at the University of Cape Town (UCT). She heads up the

research work on lightweight materials at the Blast Impact and Survivability Research Unit (BISRU) at UCT. She investigates blast-resistant materials and structures for use in structural and transportation applications. She seeks to make the world a safer place by improving our understanding of a structure’s response to explosion loading. She has a PhD in Mechanical Engineering from the University of Liverpool. She has published her research in many journal articles, conference proceedings, popular media and books. Genevieve is also a chartered engineer, member of the South African Young Academy of Sciences and an NRF-rated research scientist.

What happens after an explosion?

A shock wave is created that rapidly compresses the surrounding air. This causes a high-pressure blast wave which has a very short duration, shown in the graph.

A graph showing what happens to pressure over time after an explosion.

Image: Genevieve Langdon

The blast wave travels through the air and has destructive effects on objects in its path. As the blast wave comes into contact with an object, a very high pressure rise occurs almost instantaneously, followed by a decrease in pressure back to atmospheric pressure. This is called the positive phase. Subsequently, the pressure continues to drop below atmospheric, and a negative phase with a vacuum (like a suction) occurs.

Usually the negative phase is disregarded, but it can be important for materials like glass. The peak pressure magnitude and duration of the blast wave depend upon (among other things): n The source of the explosion (how much explosive, what type, how it was detonated) n The distance travelled by the blast wave (the pressure decreases with distance) and what it’s travelling through (e.g. air, water or sand) n Whether the blast was confined, which would alter the path of the blast wave and possibly multiply the explosive energy.

The distance between the explosion source and the object of interest is known as the stand-off distance. Increasing the stand-off distance causes the pressure magnitude to decrease and the blast duration to increase. Blast waves travelling large stand-off distances are known as far-field explosions and can be modelled using relatively simple equations for basic cases. Short stand-off distance blasts are called near-field explosions and are extremely difficult to understand and model accurately.

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OBSESSIVE-COMPULSIVE DISORDER:

when once is never enough

Christine Lochner and Elsie Breet explain this common and often disabling condition.

In the image the heat scale indicates regions where OCD patients differ significantly from controls at the whole brain level. Image: brainethics.wordpress.com

What is neuroimaging?

Neuroimaging uses various techniques to either directly or indirectly make an image of the structure, function or pharmacology of the nervous system. It is a relatively new discipline within medicine and neuroscience, psychology and psychiatry.

There are two broad categories: 1. Structural imaging, which deals with the structure of the nervous system and the diagnosis of gross (large-scale) diseases within the brain (such as tumours) and injuries.

2. Functional imaging, which is used to diagnose metabolic diseases and lesions on a finer scale (such as Alzheimer’s disease) and also for neurological and psychological research and building brain-computer interfaces.

Functional imaging allows, for example, the processing of information by centres of the brain to be visualised directly.

Source: http://en.wikipedia.org/wiki/Neuroimaging

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t is normal, on occasion, to go back and check that the stove is switched off or that your car is locked, or to make sure that things in the office or at home are neatly organised. But people with obsessive-compulsive disorder (OCD) may spend many hours a day checking and ordering/ arranging. This behaviour arises in an attempt to counter the anxiety provoked by intrusive thoughts about, for example, harm happening to themselves or their loved ones, or about chaos in the workplace or at home. These obsessive thoughts or images and so-called compulsive behaviours may become so extreme that they take up a significant number of hours per day, cause terrible distress and significantly interfere with normal life. For individuals with these symptoms, it may feel like no matter what they do, they just cannot get rid of them.

In order to learn more about this disabling illness, researchers from the MRC Unit on Anxiety and Stress Disorders at the Universities of Stellenbosch and Cape Town are conducting a study focused on the phenomenology, psychobiology and neuroimaging of OCD. Much of the work concentrates on determining the clinical features (e.g. age of onset, typical obsessive-compulsive symptom profiles, and any other co-existing illnesses such as depression) and the neurobiology underlying this condition in South African patients. Ultimately, the aim is to link the significant clinical aspects of this condition with its neurobiology as well as with specific brain structures involved.

Increased knowledge may lead to novel and more optimal treatment strategies that benefit patients, and that will hopefully ultimately translate into a better quality of life for all of those affected (including family or significant others).

What research is being done on OCD at the MRC Unit on Anxiety and Stress Disorders?

The group, lead by Director Prof. Dan Stein, is carrying out extensive research around OCD and related disorders such as hair-pulling disorder (called HPD or trichotillomania).

Affected people start with an interview with a clinical psychologist and then go for a series of investigations, including neurocognitive testing and neuroimaging. The unit is also interested in the genetic basis for the disorder and so blood or saliva samples are used to extract DNA. q

For more information contact the MRC Unit on Anxiety and Stress Disorders (tel: 021 938 9179/9654; cl2@sun.ac.za), or the Mental Health Information Centre of Southern Africa (tel: 021 938 9229; mhic@wun.ac.za; www.mentalhealthsa.org.za).

What is OCD? OCD is a brain disorder characterised by obsessions and compulsions. Obsessions are persistent, ‘self-generated’ thoughts, which may seem impossible to control, which are not simply worries about the person’s everyday problems, and which are intrusive and unwanted enough that the person tries to get rid of these thoughts with other thoughts or actions, which are called ‘compulsions’.

Compulsions are repetitive acts that a person feels compelled to carry out over and over, e.g. washing hands, checking doors/stoves/electric plugs, ordering/arranging, or counting. These compulsions are aimed at reducing distress (i.e. they are not inherently enjoyable as is typical of drug abuse/addictions), and are associated with an obsession or are aimed at preventing a feared event (e.g. hurting a loved one).

Excessive handwashing is a common symptom.

Image: Lars Klintwall Malmqvist (Larsklintwallmalmqvist) - Own work. Licensed under Public domain via Wikimedia Commons.

Symptoms and signs of OCD Commonly, people with OCD experience both obsessions and compulsions but in some cases people experience just one or the other.

Examples of obsessions: n Harm-related concerns n Sexual/religious/morality concerns n Obsessions with symmetry/order n Contamination fears n Hoarding/saving n Concerns with having an illness.

Examples of compulsions: n Checking n Ordering/arranging n Washing/cleaning n Hoarding rituals.

You may have OCD if your obsessions and/or compulsions cause marked distress, interfere significantly with your daily routine, are not productive, and take up a significant amount of your time.

What is the cause of OCD? There is no single, proven cause for OCD. It is likely that both genetic and environmental factors are involved. Genetic research has shown that a number of genes may play a role in the development of the disorder. Several parts of the brain are involved in anxiety.

Research suggests that OCD is related to faulty communication between the front part of the brain (the orbital cortex) and deeper structures (the basal ganglia). These brain structures are regulated by, for example, serotonin, which is one of the neurotransmitters (the chemical ‘messengers’ between nerve cells).

OCD may also be associated with some autoimmune reactions (in which the body’s disease-fighting mechanism attacks normal tissue). The condition sometimes starts in childhood in association with strep throat (a sore throat caused by infection with Streptococcus bacteria). Research suggests that the infection does not actually cause OCD, but it may trigger OCD symptoms in children who may have a genetic predisposition to the disorder.

OCD also has a familial component.

Some studies suggest that 25% of people with OCD report that they also have a family member with OCD. Also, twin studies have shown us that OCD is more prevalent among identical twins when compared with fraternal twins. Although researchers do not yet fully understand the genetic mechanisms underlying OCD, it is believed that a number of different genes may play a role.

During and after pregnancy women with OCD experience an increase in hormones that may make their OCD symptoms worse.

Undoubtedly, all parents experience some anxiety associated with new responsibility and the accompanying set of concerns for the new

Prof. Christine Lochner completed her PhD (Psychiatry) at Stellenbosch University. She was appointed as a full-time researcher and Co-Director of the MRC Unit on Anxiety and Stress Disorders, a centre of international excellence in psychiatric genetics, psychiatric brain imaging, basic neuroscience, and mental health promotion. She is interested in the phenomenology, psychobiology and neuroimaging of obsessive-compulsive (OCD) and OCDrelated disorders such as hair-pulling disorder (trichotillomania (TTM)). In addition, her foci also include anxiety disorders like social anxiety disorder (SAD). These disorders are associated with significant distress, functional impairment and costs – to the individual and his/her family, as well as society. Much of Prof. Lochner’s phenomenological work concentrates on determining the (sub-)structure of these conditions. The purpose of the psychobiological research is to determine the underlying neurogenetics of each, and now, increasingly, on gene-imaging correlations. The ultimate aim of this work is to link the significant clinical aspects of these conditions with their neurobiological underpinnings and with the specific involved brain structures.

addition to the family. However, after the birth, women with OCD may experience disturbing obsessions (e.g. fears related to contaminating or hurting the baby) and compulsions (e.g. repeatedly washing the baby or re-organising the baby’s crib).

Environmental factors (e.g. abuse, relationship changes, traumatic life events such as witnessing a crime, and school-related problems) may also play a role in the onset or severity of OCD.

How is OCD diagnosed?

There is no clear laboratory test for OCD. Diagnosis is based on a thorough assessment of symptoms. To be diagnosed with OCD, an individual has to meet the criteria in the internationally recognised diagnostic manual published regularly by the American Psychiatric Association (DSM). In some cases it is difficult to make a diagnosis of OCD because the symptoms may be similar to other mental health disorders or people may hide their symptoms due to stigma related to mental illness.

Can OCD be treated?

In OCD, antidepressants (serotonin re-uptake inhibitors (SRIs)) and cognitive-behavioural therapy (CBT) – which includes exposure and response prevention (ERP) – are wellestablished safe and efficacious first-line treatments in adults and children. CBT may be helpful in patients not responding to SRI treatment. Although it may take some time before there are marked changes, a good response is sometimes seen. In research settings, there has been ongoing interest in finding alternative treatments for patients not responding to these first-line options. For example, so-called repetitive transcranial magnetic stimulation (rTMS), and deep brain stimulation (DBS) and other neurosurgical approaches have been studied in OCD, but are not yet considered first-line approaches.

Can OCD be prevented?

At present there is no known prevention for OCD. However, early diagnosis and correct treatment can help people to avoid the suffering associated with the condition and lessen the risk of developing other problems, such as depression or relationship and work difficulties.

From left to right: Ms Karin Swanepoel, Dr Annerine Roos, Dr Sharain Suliman, Ms Elsie Breet, Prof. Christine Lochner, Prof. Dan Stein, Ms Janine Roos.

Image: MRC Unit on Anxiety and Stress Disorders

She is one of the Founding Members of the South Africa Young Academy of Science (SAYAS).

Elsie Breet is the assistant researcher for Prof. Christine Lochner and is working on a genetics of anxiety disorders research project at the MRC Unit on Anxiety and Stress Disorders, Department of Psychiatry, focusing specifically on behavioural aspects of OCD. Her duties include: administrative tasks; data entry; writing of papers for publication; poster/oral presentations for various conferences; and assisting in studies (genetics, OCD, trichotillomania, skin picking, social phobia).

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Tuberculosis (TB) control in an era of emerging non-communicable diseases Tolu Oni and a team of researchers are investigating the interaction between TB, HIV and diabetes in Cape Town.

S

outh Africa is among the 22 high TB burden countries globally, and also has the highest urban:rural ratio in sub-Saharan Africa, with 62% of the population being urban dwellers.

Urbanisation, in addition to causing rapid changes in the make-up of the population (called an epidemiological transition), has resulted in a rising burden of non-communicable diseases (NCDs) such as type 2 diabetes and heart disease. What we do not yet fully understand is the relationship between infectious diseases such as TB and the increasing rate of NCDs, particularly type 2 diabetes, which

depresses the immune system.

The global burden of disease study demonstrated that in Southern Africa, while HIV and TB rank first and fourth in the top ten causes of morbidity, diabetes is ranked eighth. Mortality rates from NCDs are also increasing.

TB remains a leading cause of death, with an estimated 8.8 million new cases reported every year.

Tackling this challenge will require not only improvements in diagnostics, but identification and reduction of risk factors that increase TB susceptibility.

TB risk factors HIV is the strongest risk factor for TB and >60% of TB patients also

The relationship between infection with TB, poor immunity and poor living conditions and non-communicable diseases. Image: Tolu Oni

Terminology

Definition

Epidemiological transition

Phases of development characterised by a change in the pattern of diseases from predominantly infectious pandemics to chronic degenerative diseases over time

Mortality

Causes of death

Glycaemic control

Optimal management of diabetes such that sugar levels are within the desired range

Prevalence

Number of existing cases of a disease

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have HIV infection in South Africa.

While the link between HIV and TB is well-recognised, other diseases and risk factors that impair immune function, such as tobacco smoking, malnutrition, alcoholism, and diabetes can also increase the risk of TB. The diagram shows that risk factors such as poor nutrition, alcohol abuse, and tobacco increase both the risk of TB and the risk of common NCD such as diabetes. In addition, diabetes and chronic obstructive pulmonary disease (COPD) increase the risk of TB. This is of particular concern because the number of people with diabetes in South Africa is rising and the risk factors for diabetes including obesity, low physical activity, and a high dietary sugar intake are very common.

TB and diabetes Evidence suggests that diabetes can increase the risk of TB by up to three times. However, none of these studies were conducted in sub-Saharan Africa, raising uncertainty about the contribution of diabetes to the TB epidemic and the impact of HIV co-infection in sub-Saharan Africa.

The co-existence of diabetes in TB patients is associated with a longer duration of TB symptoms, more severe TB disease, poorer TB outcomes and a higher rate of TB relapse, with greater mortality reported among TB patients with diabetes compared with those without diabetes. Type 2 diabetes is the more common form of the disease. There is also some evidence to suggest further increased TB risk in people with poor blood glucose (glycaemic) control. TB can aggravate diabetes by worsening blood glucose control, complicating the management of both diseases.

❚❚❚❙❙❙❘❘❘ Fact file

What is TB? Tuberculosis (TB) is a disease caused by Mycobacterium tuberculosis.

The disease occurs throughout the world, but is uncommon in Western countries where living conditions are good.

TB is usually thought of as a disease that affects the lungs, but any part of the body can be infected.

Symptoms Classic symptoms of pulmonary TB (90% of infections) are: n Cough, sometimes with blood-stained sputum n Fever n Night sweats n Loss of appetite and weight loss.

There are a variety of other symptoms when TB affects other part of the body. Pulmonary TB is spread through the air in droplets as people cough and sneeze, which is why the disease is more common in overcrowded conditions.

Distribution of disease One-third of the world’s population is thought to have been infected with TB, with new infections occuring in about 1% of the population each year. In 2010 there were about 8.8 million new cases of the disease and 1.5 million deaths – mainly in developing countries. In the developing world TB is particularly common because of co-infection with HIV, which depresses the immune system, allowing the infection to take hold.

Source: http://en.wikipedia.org/wiki/Tuberculosis

Diagnosis TB is diagnosed from the symptoms, from a chest X-ray and from examination and culture of the sputum.

Chest X-ray of a person with advanced tuberculosis: Infection in both lungs is marked by white arrow-heads, and the formation of a cavity is marked by black arrows. Image: ‘Tuberculosis-x-ray-1’. Licensed under Public domain via Wikimedia Commons

Treatment TB is a difficult infection to treat and multiple antibiotics have to be taken for at least six months. The drugs have unpleasant side-effects and people struggle to continue treatment for such a long time. In South Africa treatment is usually observed – patients have to take the drugs under supervision (at work or at a clinic), which is another difficulty.

There are now many strains of TB that are resistant to the commonly used antibiotics – multidrug-resistant TB (MDR-TB). More recently extensively drug-resistant TB (XDR) TB has arisen, which is very difficult and sometime impossible to treat.

The main symptoms of variants and stages of tuberculosis are given, with many symptoms overlapping with other variants, while others are more (but not entirely) specific for certain variants. Multiple variants may be present simultaneously. Image: Häggström, Mikael. ‘Medical gallery of Mikael Häggström 2014’. Wikiversity Journal of Medicine 1 (2). DOI:10.15347/wjm/2014.008. ISSN 20018762. - All used images are in public domain. Licensed under Public domain via Wikimedia Commons.

Diabetes

The research A team of researchers from the Clinical Infectious Disease Research Initiative at the University of Cape Town is conducting research to understand the contribution of diabetes to the TB epidemic in a high HIV/TB co-infection setting.

Data collection began in August 2013 and 800 study participants will be recruited. In Khayelitsha, where the study is being conducted, the prevalence of diabetes is approximately 12%. Earlier work conducted by this team found that a quarter of TB patients were overweight or obese, a risk factor for diabetes.

Results from the study will provide evidence of the contribution of diabetes to the burden of TB and the best approach to screen TB patients

There are two forms of diabetes, type 1 and type 2. Type 1 diabetes usually starts in childhood and is caused by destruction of the insulin-producing cells of the pancreas – the islets of Langerhans.

This occurs after an infection that then causes the body’s immune system to destroy these cells.

Another, uncommon, form of diabetes occurs in pregnancy. Type 1 diabetes and diabetes in pregnancy make up about 10% of cases. Type 2 diabetes makes up the remaining 90% of cases.

Type 1 diabetes is treated with insulin injections.

Type 2 diabetes is a disease of metabolism in which the body can no longer respond to insulin and so blood glucose levels rise. The majority of people who develop type 2 diabetes are obese, but there is a small group of people who develop the disease at normal weights.

Type 2 diabetes is treated with a combination of drugs and diet. In obese people with the disease, weight loss and exercise are an important part of the treatment.

Symptoms and consequences of type 2 diabetes The classic symptoms of type 2 diabetes are excessive thirst, frequent urination and constant hunger.

Type 2 diabetes affects every part of the body and poor blood sugar control leads to complications such as poor blood flow to the legs and feet, leading to amputations, loss of feeling in the feet (called peripheral neuropathy), damage to the retina of the eye, leading to blindness, damage to the kidneys, heart disease and stroke.

The diabetes epidemic The number of people with type 2 diabetes has massively increased around the world since the 1970s, in parallel with the epidemic of obesity. In 2010 there were about 285 million people diagnosed with the disease, compared with around 30 million in 1985.

for diabetes in order to improve joint TB and diabetes management. q Dr Tolu Oni is a Senior Research

Medical Officer at the Institute of Infectious Disease and Molecular Medicine, University of Cape Town.

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The transient universe Patrick Woudt and Vanessa McBride take a look at some of the ‘newer’ objects in the Universe.

Above: The new nova in the constellation of Centaurus, near the iconic Southern Cross and the two pointers at ESO’s La Silla Observatory in the Chilean Atacama Desert in the morning hours of Monday 9 December 2013. The nova was discovered by John Seach from Australia on 2 December 2013 as it approached naked-eye brightness. Nova Centaurus 2013 is the brightest nova to have occurred so far this millennium. Image: Y. Beletsky (LCO)/ESO

In this artist’s impression of the binary star system RS Ophiuchi, which is a recurrent nova with nova explosions ~ every 20 years. Image: David A. Hardy http://www.astroart. org & Science and Technology Facilities Council

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owards the end of last year, the Australian amateur astronomer John Seach discovered a new star near the Southern Cross in the constellation of Centaurus. This new object in the sky is called Nova Centaurus 2013, or V1369 Cen, the 1 369th variable star known in this constellation. Variable stars are stars that change in brightness over time on time scales as short as seconds or as long as years. V1369 Cen appeared on 2 December 2013 following a stellar explosion and was visible to the naked eye for almost two months, while slowly fading. V1369 Cen was the brightest nova in more than a decade, and the second brightest in nearly 40 years. In ancient times such new stars in the sky were called stella nova (Latin for ‘new star’), which has been simplified over the years to ‘nova’. Nowadays astronomers distinguish between different kinds of novae, to highlight the different physical processes that set them apart.

Cosmic explosions – bright, brighter, brightest A classical nova, for example, occurs when gas from a companion accumulates on the surface of a white dwarf (see box on compact stellar objects) and is ejected explosively into interstellar space. Such events occur where two stars orbit each other so closely that one star (the less massive one) continuously loses a fraction of its mass to the more massive star (the white dwarf), under the influence of gravity. This is known as a compact binary.

When the accumulated material on the surface of the white dwarf reaches a critical density and temeperature, nuclear reactions give rise to a rapid increase in temperature and pressure, which leads to a runaway process on the surface of the white dwarf. A cataclysmic explosion follows. The nova

❚❚❚❙❙❙❘❘❘ Astronomy

The crab nebula This image of the Crab Nebula, obtained with NASA's Hubble Space Telescope, shows the remains of a star that became a supernova in 1054. Japanese and Chinese astronomers recorded this event in 1054 CE, as a 'guest star' that reached naked eye brightness and was visible during the day for nearly a month.

The filamentary structures give a good impression of the destructive force of such a stellar explosion. The outer parts of the star have been blown off into interstellar space and have expanded ever since, colliding with material that surrounded the supernova. At the heart of the Crab nebula is a rotating neutron star, the compact core of the star that exploded in 1054. If a rotating star collapses, conservation laws in physics dictate that such a star must rotate faster after the collapse. In this case, the ultracompact neutron star rotates 30 times a second (compare this with the rotation rate of the Sun: 1 rotation every 24.5 days at the solar equator).

The diameter of the Crab Nebula nearly 1000 years after the explosion is around 6 light years (larger than the distance from the Sun to the nearest star: alpha Centauri). The Crab Nebula is located at a distance of 6500 light years in our own Milky Way The crab nebula. Image: By NASA, ESA, J. Hester and A. Loll (Arizona State University) (HubbleSite: gallery, release.) via Wikimedia Commons

explosion blows off the outer layer of the white dwarf with tremendous amounts of energy.

After this explosion, an equilibrium is re-established and gas transfer resumes. The outburst cycle repeats on time scales between tens of years to tens of thousands of years.

In our own Galaxy, there are about 30 – 40 novae per year.

Unfortunately, we don’t always see each nova explosion, as some might occur on the far side of the Milky Way, and would be heavily obscured by interstellar dust.

A supernova, as the name suggests, is associated with a much more energetic process. A supernova can occur in the compact binary systems described above, where, after many nova cycles, so much gas has accumulated from its companion star that it reaches the maximum mass it can sustain.

This limit is 1.4 times the mass of the Sun and is called the Chandrasekhar mass limit, named after the Indian astronomer who first derived this. In these systems the supernova either destroys the white dwarf, or forms a neutron star by collapsing in on itself. A supernova also occurs when single massive stars (more than 10 – 20 times the mass of the Sun) collapse at the end of their lives. In these events, a neutron star or a black hole is formed.

In a matter of seconds, a supernova explosion releases about the same amount of energy that the Sun would take 10 billion years to release. The last directly observed supernova in our Galaxy occurred in 1604, and is also known as Kepler’s supernova. Around two supernovae per century occur in the Milky Way, or one every 50 years. We have probably missed a few supernovae since 1604 as they could have been hidden by interstellar dust in our Milky

Way. By contrast, given their tremendous brightness at the peak of the explosion, we can see them at tremendous distances in many other galaxies. The Nobel prize in Physics in 2011 was awarded to three astronomers who used distant supernovae to study the geometry of the Universe and who showed that the expansion of the Universe is accelerating.

Searching the skies for transient phenomena Nowadays a number of optical telescopes are dedicated to observe the transient night sky, in constant search of new kinds of variable stars and distant supernovae in far-away galaxies. Astronomers search the whole sky for the tell-tale signs of these cosmic explosions. One of current ‘transient’ surveys is the Catalina Real-Time Transient Survey. The initial aim was to search for asteroids and near-Earth objects in the solar system, to identify asteroids that might be on a collision course with Earth. The astronomers soon realised that such a search would also reveal thousands of supernovae and other kinds of temporary (transient) celestial phenomena beyond the solar system.

After a decade of scanning the skies, the Catalina Real-Time Transient Survey has observed over half a billion objects and has found nearly 10 000 new optical transients and over 2 000 new supernovae. And this is only a drop in the ocean. Future surveys will find these numbers of transients each night.

To keep up with this rate of discovery, the data are released publicly, both as an archive that astronomers around the world can access for their research, as well as instant alerts of new and interesting objects via mobile apps for everyone to see. You can download an application to keep track of all the objects found by the Catalina survey by searching for Transient Events™ on Google.

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Compact stellar remnants A white dwarf is the compact core of a star that was once similar to our own Sun. It is approximately the size of the Earth and contains about 60% of the mass of our Sun. In about 5 billion years our Sun will become a white dwarf.

Neutron stars are more massive and more compact than white dwarfs. These stars contain 1.4 times the mass of the Sun in a star the size of a big city (ten kilometre radius). They are the collapsed cores of massive stars at the end of their stellar evolution.

Black holes are the stellar end-products of the most massive stars, where the core of the star has collapsed on itself to such high density that even light can no longer escape. They are only observable in compact binary systems where we can see the companion star losing material to the black hole.

This is an artist’s impression of the thin, rocky debris disc discovered around the two Hyades white dwarfs. Rocky asteroids are thought to have been perturbed by planets within the system and diverted inwards towards the star, where they broke up, circled into a debris ring, and were then dragged onto the star itself. Image: NASA, ESA, STScI, and G. Bacon (STScI) via Wikimedia Commons

The first direct observation of a neutron star in visible light. The neutron star being en:RX J185635-3754.

Artist's rendition of a black hole with an orbiting companion star that exceeds its Roche limit. Mass from the companion star is drawn towards the black hole, forming an accretion disk.

Image: Fred Walter (State University of New York at Stony Brook) and NASA. Source: ST Scl.

Image: Wikimedia Commons under Creative Commons

By 2020, the Large Synoptic Survey Telescope, an 8-m optical telescope with a 3-billion pixel digital camera, will be able to scan the entire sky twice a week and report hundreds of thousands of transients each night. That is more than 1 transient alert each second of each day – your cellphone Transient Events™ app will be buzzing all the time.

Robotic telescopes and data scientists Clever software is needed to decide which object is interesting enough to follow up with telescopes, such as our very own SALT (the world’s largest optical telescope, located in Sutherland, South Africa). Time on telescopes like SALT is precious and we simply cannot observe all the interesting objects we find.

To look at the transient Universe in a new way, astronomers have joined forces with computer scientists and software engineers to make sure they can keep up with the tremendous data streams of the new telescopes. It requires fast computing to keep up with the terabytes of data coming from the telescopes. It also requires clever and cognitive 14

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computing to identify the peculiar stars discovered this way.

Eventually it will lead to instant automated computer-based decisions to select follow-up observations on an array of telescopes on the fastest possible time scales.

The next generation of astronomers will be skilled data scientists, able to deal with all this vast information at their fingertips. It is simply impossible for a single astronomer, or even a group of scientists, to look at 100 000 objects each night and make a quick decision about what to observe, and if you don’t, the flow of data rapidly gets out of control.

Already some of the world’s large telescopes receive robotic triggers to study individual stars in more detail. More and more telescopes will operate in this way in the future.

Don’t blink Studies of the transient skies are not limited to optical astronomy. The cosmic explosions associated with novae and supernovae, release energy across a wide range of the electromagnetic spectrum. Supernova-induced shocks occur in the interstellar medium and can be traced by

radio telescopes. These telescopes also trace other transient signals. For example, when a star strays too close to a supermassive black hole, the star can be destroyed by tidal forces and some of the star ‘stuff ’ gets ejected as a jet moving at velocities near the speed of light.

By exploring the transient Universe on a range of time scales, we are finding more unusual phenomena. In only the last few years astronomers have found short bursts of radio emission lasting approximately 10 milliseconds. These objects are called ‘Fast Radio Bursts’ and about 10 are now known. The signal does not re-occur, so if you blink you miss them. Fortunately, nowadays all data are recorded and can be re-analysed by fast computers. Unfortunately, while we can find these objects in the archives, no trace remains visible. We therefore don’t know how far away they are or how much energy is released by the radio burst. If we can catch a fast radio burst in real time, and have an optical flaring counterpart, we can uniquely identify the origin of this mysterious signal and determine the physical processes giving rise to it.

MeerKAT and the transient Universe South Africa’s large radio telescope, MeerKAT, and the Square Kilometre Array after it, will also look at the transient sky. Two of the ten large MeerKAT surveys – ThunderKAT and TRAPUM – will scan the radio sky continuously for cosmic explosions and fast radio bursts at radio frequencies. The ThunderKAT and TRAPUM science teams are developing computational tools to scan the full MeerKAT data stream 24/7 for transient signals on all time scales (from milliseconds to hours and days) using a range of new and innovative techniques.

The ThunderKAT project will also build a new optical telescope called MeerLICHT, which will be located at the national South African Astronomical Observatory in Sutherland. This telescope will be exclusively tied to the MeerKAT observing schedule. In this way we can observe the transient sky at optical and radio wavelengths at the same time, all the time, in a way never done before. This will be incredibly useful for scientists who are looking at understanding the cosmic explosions at radio frequency.

MeerLICHT is a modest-sized telescope – it has a mirror of 60 cm diameter – but it is entirely robotic. It will be run by a suite of computers which will get the pointing direction from the MeerKAT control room, check the local weather and execute an observing programme without any human intervention. Any cosmic explosions detected by MeerLICHT in the optical will be broadcast to other astronomers in real time so that they can point their telescopes in the same direction. MeerLICHT will be installed and observing from Sutherland by the end of 2015.

The transient Universe in the classroom The MeerLICHT and ThunderKAT science teams are actively looking for involvement of South African high school learners in the science exploration of the transient Universe. You can get involved when MeerKAT is up and running in 2017 when we will detect a large number of transients that can be studied in detail with smaller telescopes. The observatory in Sutherland hosts a number of robotic telescopes that can be used for this purpose. One particular telescope, MONET (short for MOnitoring NETwork), can be remotely controlled via a web

The MeerKAT core from the air. Image: SKA South Africa

The mirrors of the Southern African Large Telescope.

Image: Roelof Valentine via Wikimedia Commons

interface from your classroom. Learners and scientists working together to interpret this wealth of data will be an integral part in exploring the mysteries of the transient Universe. Q Patrick Woudt is an associate professor in the Astronomy Department at the University of Cape Town. He is the deputy Head of Department and studies the physics of accretion in compact binaries through optical and radio observations. He is a principal investigator of both the ThunderKAT and the MeerLICHT projects.

Vanessa McBride is a lecturer in the Astronomy Department at the University of Cape Town. She holds a joint position between the University of Cape Town and the South African Astronomical Observatory. She studies accretion processes in neutron star binaries, mostly through X-ray and optical observations. Vanessa is the project manager of the MeerLICHT project.

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Earlier Stone Age artefacts found in Northern Cape The importance of intensive archaeological research to heritage conservation.

Quest with the University of Cape Town and the University of Toronto.

E A. Location map within South Africa. B. Location map with relation to the regional topography and Wonderwerk Cave. C. Topographic context of sites of the Kathu Complex discussed in this article. Grey shading indicates developed areas and areas undergoing development. Note that the boundaries of Kathu Pan are approximate and do not indicate the limit of areas of archaeological potential. Image: doi:10.1371/journal.pone.0103436.g001

xcavations at an archaeological site at Kathu in the Northern Cape province of South Africa have produced tens of thousands of Earlier Stone Age artefacts, including hand axes and other tools. These discoveries were made by archaeologists from the University of Cape Town (UCT - South Africa) and University of Toronto (Canada), in collaboration with the McGregor Museum in Kimberley (South Africa).

The archaeologists’ research on the Kathu Townlands site, one of the richest early prehistoric archaeological sites in South Africa, was published in the journal PLOS ONE on 24 July 2014. It is estimated that the site is between 700 000 and one million years old.

A. Digital Elevation Model (DEM) showing the topographic context of Kathu Townlands. Square shows the approximate area shown in B. (DEM courtesy of Stephen Wessels, The Zimani Project). B. Aerial photo of Kathu Townlands.

White shading indicates approximate limits of the declared locality. Asterisk indicates location of 2013 excavations. Image dated 5/27/2011 predates recent development south of Frikkie Meyer St. Image source Terraserver. C. View of Towlands site north of Frikkie Meyer St. D. Detail showing scatter of artefacts on the surface of the site north of Frikkie Meyer St. Image: doi:10.1371/journal.pone.0103436.g002

History versus modern development One of the important features of this site is that it is an example of an ancient settlement that appears to have been formed because the geology of the area makes it perfect for the manufacture of stone tools. Kathu Townlands is situated between the Kuruman Hills to the east and the Langberg mountains to the west on a low hill. The surface of the site is literally covered in the artefacts (lithics) produced by intensive manufacture of stone tools, interspersed with exposed bedrock, calcrete and sand. The presence of these areas of intense manufacturing and probably transport of stone tools also provides information – and raises questions – about how and why groups of people settled in particular areas and how they lived in these areas.

However, the threat to this important site is that the town of Kathu is rapidly expanding and this development is directly threatening Kathu Townlands. The site was designated a Grade 1 National Heritage site in 2013, but the threat to the deposits that are present beyond the declared area is serious. Today, Kathu is a major iron mining centre.

‘The fact that such an extensive prehistoric site is located in the middle of a zone of intensive development, poses a unique challenge for archaeologists and developers to find strategies to work cooperatively’, says Steven James Walker from the Department of Archaeology at UCT and lead author of the journal paper.

An early indication of the potential threat to the preservation of archaeological remains was, in fact, the way in which the site was brought to the attention of scientists in 1980. It was Naas Viljoen, the manager of the property on which Kathu is situated, who saw workmen using gravel that was made up primarily of artefacts to repair roads.

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❚❚❚❙❙❙❘❘❘ Archaeology Flakes and cores from Kathu Townlands, Beaumont Excavation

Steven James Walker from the Department of Archaeology at UCT extracts a sample at the interface between the overlying red sands and the Earlier Stone Age archaeological deposits at the Kathu Townlands site. Image: Vasa Lukich

A: Large flake off the edge of the core consistent with biface shaping removal. B: Large flake with centripedal dorsal scars. C: Blade, note that there is some cortex (indicated by C in the sketch) and that scars are not parallel. D-F: Small flakes, note that F is off the edge of the core.

G: Discoidal core with removals off both faces. Break on one edge (upper edge in right view). H: Discoidal core with one large flake removal. Note that on the right-hand face the working is unclear and it is possible that this is a natural surface. Image: Steven James Walker and colleagues

Hand axes from surface collection. A-B. Banded Ironstone. C. Quartzite. Image: Steven James Walker and colleagues

Profiles from the 2013 excavation

Archaeologists are also still not sure exactly how extensive the deposit is and the total extent of the deposit, particularly beneath the surface sands, is still to be worked out.

Walker goes on to say, ‘The site is amazing and it is threatened. We’ve been working well with developers as well as the South African Heritage Resources Agency to preserve it, but the town of Kathu is rapidly expanding around the site. It might get cut off on all sides by development and this would be regrettable’.

The Kathu Complex The Kathu Townlands site is one component of a grouping of prehistoric sites known as the Kathu Complex. Other sites in the complex include Kathu Pan 1 which has produced fossils of animals such as elephants and hippos, as well as the earliest known evidence of tools used as spears from a level dated to half a million years ago.

Professor Michael Chazan, Director of the Archaeology Centre at the University of Toronto, emphasises the scientific challenge posed by the density of the traces of early human activity in this area.

‘We need to imagine a landscape around Kathu that supported large populations of human ancestors, as well as large animals like hippos. All indications suggest that Kathu was much wetter, maybe more like the Okavango than the Kalahari. There is no question that the Kathu Complex presents unique opportunities to investigate the evolution of human ancestors in Southern Africa,’ says Professor Chazan. Q

A. Trench A: Square 1. Massive deposit of Banded Irontone rubble and artefacts overlying bedrock in a sandy matrix. Note lack of bedding or sorting.

B. Trench I: Square 5. Shallow massive deposit of Banded Ironstone rubble and artefacts overlying bedrock with overlying deposits of sand.

C. Trench E: Square 3. Discrete calcrete nodule that developed near the interface of the rubble/artefact deposit and underlying bedrock. Note parallel bedding of the Ironstone within the calcrete nodule. Approximate width of image 50 cm.

D. Trench J/K. Discrete nodular calcrete developing in the sand and into the underlying Banded Ironstone rubble. Does not exhibit parallel Ironstone bedding found in (c). Approximate width of images 50 cm.

Image: Steven James Walker and Colleagues

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The Taung Child:

Casting new light on human evolution Further investigation of the Taung Child skull has made us re-think some of our ideas about human evolution. Quest looks at the latest research.

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he Taung Child is possibly the most famous and most significant find in palaeoanthropology in the 20th century. The fossilised partial skull was found in 1924 by quarrymen working for the Northern Lime Company in Taung, North West Province.

When the fossil finally found its way to Raymond Dart, then professor of anatomy at the University of the Witwatersrand (Wits), he named the species Australopithecus africanus – the ‘southern ape from Africa’ – and published his findings in Nature in 1925, a mere 40 days after it was passed on to him.

Dart believed that the skull showed features of ‘an extinct race of apes intermediate between living anthropoids and man’. At the time, few agreed with him, but over time, the place of A. africanus as an intermediate was established.

Features of the partial skull The fossil consists of most of the face, the mandible with teeth and a natural cast of the brain (an endocast) –

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something that is very unusual in fossil skulls. It is estimated to be 2.5 million years old and to be from a three- to fouryear-old child.

Although the cranium has a relatively small brain capacity, Dart pointed out specific features of the Taung skull that are human-like. The teeth, for example, are human-like and the position of the foramen magnum – the large hole in the base of the cranium for the spinal cord – faces downward. This clearly shows that the child was bipedal. This suggests that the modern upright posture and bipedalism evolved first and that modern large brains and human-like intelligence evolved later.

These features are the essence of the significance of the Taung Child in current theories of human evolution.

However, research has continued on the Taung skull in order to provide further ideas about human evolution.

Recently, in 2012, researchers proposed that the Taung Child shows specific adaptations that allowed important

❚❚❚❙❙❙❘❘❘ Palaeoanthropology

Left: Composite image of Taung partial cranium, mandible, and endocast 3D renderings (left) facing a replica of the Taung partial cranium and mandible (right). This is the first endocast reconstruction visualising the brain of the specimen (Australopithecus africanus) using high-resolution computed tomography-generated images. [Black background].

Image: Image courtesy of Kristian J Carlson, University of the Witwatersrand

brain growth to continue after birth and into infancy. These adaptations – taken from standard medical computed tomography (CT) examination of the Taung cranium – are suggested by a persistent metopic (frontal) suture and an open anterior fontanelle. The metopic suture disappears when fusion of the two halves of the cranial frontal bone occurs. This suture is present in all mammals during development, and normally fuses in humans soon after birth as the anterior fontanelle closes. Sometimes, this fusion is delayed, but in neither humans nor apes is this delayed fusion and/or fontanelle closure related to any changes in the structure or organisation of the pre-frontal and frontal lobes of the brain.

However, the 2012 researchers have suggested that the delayed fusion of the metopic suture and delayed closure of the anterior fontanelle – that they have proposed to be present in the Taung skull – would have provided a selective advantage during hominin evolution. They argued that these adaptations would have been advantageous for the birth process, would have allowed a high brain growth rate during early infancy and reorganisation of the pre-frontal and frontal cortex – the areas of the human brain involved in higher cognitive functions. That these advantages occur as early in the human lineage as australopithecines rests entirely on their examination of the Taung child, since no other early evidence was identified.

An alternative hypothesis However, in a paper published in July 2014 in Proceedings of the National Academy of Sciences, palaeoanthropologists from the USA (Ralph Holloway from Columbia University and Douglas Broadfield from Florida Atlantic University) and Wits – Kristian Carlson, from the Evolutionary Studies Institute – present the findings of a new study.

One of the first problems is the state of the Taung skull itself, which may make interpretation difficult. When the fossil was found there was not the same understanding of preservation and preparation of fossils that we have now.

The endocast of the brain case has many deposits on its surface, including remnants of the cranium itself, which means that the true nature of the inside of the cranium is underneath these deposits. This means that many features are not seen, including portions of the left frontal lobe. The authors also mention ‘Dart’s exuberant use of his wife’s knitting needles to extricate the fossil from the surrounding breccia...’ which may have destroyed some of the original features of the endocast surface.

Kristian Carlson and his colleagues questioned the ancientness of these supposed adaptations facilitating postnatal brain growth. To look at the features of the fossil in more detail, they performed an in silico dissection of the Taung Child using high-resolution CT. This provided direct evidence of whether in fact the metopic suture and anterior

A cast of the Taung skull. Image: Wits University via Wikimedia Commons

fontanelle were still open in this specimen.

What they found turned the 2012 study on its head.

There was no conclusive evidence of a persistent metopic suture in the high-resolution CT scans, nor did the form of a possible remnant metopic suture match up with the description of the persistent metopic suture and the open anterior fontanelle that is described in the 2012 paper. The authors suggested that the previous study relied on standard medical CT images that may not have provided the high spatial resolution required to fully understand these features of the cranium.

Brain development In modern humans, the metopic suture usually closes three to four months after birth. But in chimpanzees, all the cranial sutures, including the metopic, close before birth – a lot earlier than in humans. This is probably because suture fusion is more strongly related to the development of teeth than it is to brain development.

The Taung Child, at between three and four years, was well beyond the age for normal closure of the frontal suture.

And development of the frontal cortex of the human brain continues long past the age at which fusion usually takes place.

The latest physical evidence does not definitely link the features of the Taung skull, or its endocast, to early prefrontal and frontal lobe expansion. This also calls into question the idea that these structures were selectively advantageous in hominin evolution, particularly in species of Australopithecus. There is still no evidence that this kind of skull adaptation evolved before the genus Homo, or for a link between these skull characteristics and early pre-frontal lobe expansion. Q 10| 4 2014

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Capacity development

in aquatic biodiversity Penny Haworth explains how SAIAB is helping to form the bedrock of the next generation of aquatic scientists in South Africa

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he United Nations General Assembly has declared 2011-2020 as the United Nations Decade on Biodiversity (Resolution 65/161) and the Convention on Biological Diversity (CBD) Strategic Plan puts emphasis on capacity-development initiatives, the continued building of public awareness around biodiversity issues and the mainstreaming of biodiversity into the broader landscape of work for sustainable development and human security.

In the South African research landscape the South African Institute for Aquatic Biodiversity (SAIAB) falls within the Biodiversity Cluster of National Research Foundation (NRF) National Facilities, and its research is focused on biodiversity

The number of students supervised and the number of postgraduate students registered by SAIAB from 2004 to 2014. Image: SAIAB

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in aquatic ecosystems, which include marine and freshwater systems. SAIAB’s focus on aquatic biodiversity is a unique scientific strength, nationally and internationally. Southern Africa is ideally placed for monitoring and documenting climate change in both marine and freshwater ecosystems.

South Africa forms the southern apex of a major continental mass, flanked by very different marine ecosystems on the east and west coasts, and projecting towards the large, cold Southern Ocean marine ecosystem. The biodiversity of inland waters is equally important and SAIAB’s scientific leadership and expertise in freshwater aquatic biodiversity are vital when dealing with issues arising from the increasing pressures of human population growth and development. As a freshwater limited maritime nation, South Africa cannot afford to underestimate the importance of the sustainable management of its aquatic resources.

SAIAB enhances its research and educational capacity through active associations and agreements with partner organisations, higher education institutions and individuals nationally and internationally. SAIAB’s researchers undertake projects that engage the research community in a collaborative way and involve students and contract researchers in almost all these projects. All research running costs are raised competitively from external sources as well as the NRF. One of SAIAB’s key strengths is specialist supervision of postgraduate students. These students form the bedrock of the next generation of resource managers, scientists and policy makers in South Africa. Postgraduate students are fully integrated into SAIAB’s research platforms and programmes and their research outputs contribute to SAIAB’s Key Performance Indicators (KPIs). Over the last 10 years SAIAB has developed a thriving postgraduate school with between 45 and 60 students every year. SAIAB students are registered predominantly at Rhodes University, but there are also students from many of the other universities According to Dr Angus Paterson, SAIAB’s Managing Director, ‘Change within the world, and indeed South Africa, is no longer an event, it is a constant. In order for an institute such as SAIAB to remain relevant within such a context it must take a hard, critical look at its internal values and its overall value to society. In order for SAIAB to continue to flourish it must ensure the following: academic excellence, direct relevance to the needs of the country, a clear niche within the National System of Innovation (NSI) and a willingness to drive transformative human capacity development.’ (Executive Overview to the SAIAB Impact Report, 2012, p.3)

Careers

ACEP Phuhlisa students. Image: SAIAB

SAIAB’s investment in human capacity development. Image: SAIAB

in South Africa. The key objective over the next few years is to maintain this number, continue to transform student demographics in aquatic biodiversity study and ensure students qualify in the minimum periods and with good results.

The South African Network for Coastal and Oceanic Research (SANCOR) reported in 2011 that marine science has not transformed significantly and meaningful work still needs to be done in this area. Gender and race transformation have been high on SAIAB’s training agenda and SAIAB has a number of key initiatives administered by a dedicated coordinator. SAIAB’s flagship Human Capacity Development Programme is run through the African Coelacanth Ecosystem Programme (ACEP). The ACEP Phuhlisa Programme in collaboration with the South African Environmental Observation Network (SAEON) Elwandle Node, the University of Fort Hare and Walter Sisulu University. In its initial three-year period (2012 – 2014) the ACEP Phuhlisa Programme grew from eight to 26 postgraduate students from these two rural Eastern Cape universities.

A vibrant post-PhD young researcher team is very important and SAIAB aims to have at least three or four young researchers (postdoctoral students, Career Awards or Professional Development Programme (PDP) Fellows) on its research team every year.

Internships In addition to the ACEP Phuhlisa Programme, SAIAB is creating a vibrant network of externally funded interns through the NRF/DST and other relevant internship programmes.

Interns at SAIAB operate across a variety of fields such as communications, research, collections, library and technical.

SAIAB aims to continue to have between six and eight interns per annum and transformation remains a key priority.

SAIAB maintains that it is imperative that students and interns develop science advancement and communication skills across various biodiversity disciplines and research projects. For example, through the Rhodes University Graduate Internship Programme, science communication activities form part of the development plan for the communications intern who conducts interviews with researchers in order to tell their stories through the website, media releases, magazine and popular articles. Postgraduate students and interns participate in science engagement activities such as Scifest Africa, Water World and National Science Week as role models.

As well as academic support, which includes courses on academic writing and statistics, life-skills development for ACEP Phuhlisa Programme students include first-aid courses, swimming lessons and life-jacket training. Image: SAIAB

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The number of interns from 2005 to 2014. Image: SAIAB

The racial and gender ratios of interns from 2005 to 2014. Image: SAIAB

SAIAB’s research staff are involved in undergraduate teaching, predominantly at Rhodes University, with guest lectures being given at the University of Fort Hare. When funds allow, through the ACEP Phuhlisa Programme, SAIAB runs vacation programmes which target undergraduate students from Eastern Cape universities (predominantly the University of Fort Hare and Walter Sisulu University). The programme introduces undergraduate students to marine sciences in general and marine biology specifically in order to help them make informed career choices.

Key initiatives 2015 – 2018 to ensure a competitive place within the National System of Innovation n Continuation of the DST flagship marine research programme, ACEP n Continued growth of the ACEP Phuhlisa Programme n Securing of six to eight internships per year from the DST/NRF and Rhodes University internship programmes n Maintaining a vibrant post-PhD research team through postdoctoral, PDP and Career Award programmes n Actively targeting the various National Research Foundation (NRF/RISA), Water Research Council (WRC), Department of Agriculture, Forestry and Fisheries (DAFF), and other calls for research funding.

Featured young scientists from SAIAB PDP Postdoctoral Fellow, Dr Darragh Woodford: Managing invasive species presents a ‘wicked problem’ 22

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SAIAB PDP Postdoctoral Fellow, Dr Darragh Woodford, spent five weeks in August-September this year on an academic visit to Canada, jointly sponsored by SAIAB and the Canadian Aquatic Invasive Species Network (CAISN), which saw him visit hosts Prof. Nick Mandrak at the University of Toronto and Prof. Hugh MacIsaac at the Great Lakes Institute for Environmental Research, Windsor University.

The main purpose of the visit was to continue a paperwriting collaboration that began at a joint workshop between the DST/NRF Centre for Invasion Biology (CIB) and CAISN in Stellenbosch in November 2013. A key topic of the workshop was understanding how the management of invasive species presents a ‘wicked problem’, a management task that is difficult to tackle because both the problem and its solutions are hard to agree upon. Dr Woodford, together with SAIAB principal scientist, Dr Olaf Weyl, and other CIB core team members, will collaborate with the Canadian scientists on a review paper that assesses the various aspects of invasive species management as wicked problems. Dr Woodford’s visit to Windsor University was recently featured in a CAISN newsletter (http://caisn.ca/ flip-books/newsletter_summer_2014/).

While in Canada Dr Woodford also attended the 144th annual American Fisheries Society Conference, where he presented a paper on the management of small-mouth bass in South Africa. The talk focused on the on-going monitoring that SAIAB is performing (with funding from the Water Research Commission) on the recovery of native fishes in the Rondegat River. The stream, which was originally invaded by small-mouth bass, was rehabilitated

by CapeNature using the piscicide rotenone, which successfully removed all the bass in February 2012. The recovery of the river, together with the contributions of SAIAB, CIB, Stellenbosch University and Rhodes University, is documented in a short video produced by CapeNature that is now available to view free online (http://vimeo. com/103298963).

Full details of the rehabilitation programme can be read in the South African Journal of Science (http://www.scielo.org.za/scielo.php?pid=S003823532013000600002&script=sci_arttext&tlng=es ) and the AFS journal Fisheries (http://www.tandfonline.com/doi/abs/ 10.1080/03632415.2014.914924#.U_3t__NzaUk ).

A report on the project (KV 304/12) can be found at the WRC website: (http://www.wrc.org.za/Pages/DisplayItem. aspx?ItemID=10183&FromURL=%2fPages%2fKH_ AdvancedSearch.aspx%3fdt%3d%26ms%3d%26d%3dMon

Careers

itoring+the+Impact+and+Recovery+of+the+Biota+of+the +Rondegat+River+after+the+Removal+of+Alien+Fishes%2 6start%3d1).

Dr Woodford is also working on a project with John Measey from CIB assessing movement and/or residency of the frog species, Xenopus, in its native range, to compare with invasive populations overseas. To see the team at work go to: https://www.youtube.com/watch?v=pkBfZLdIWNs Dr Monica Mwale: Scientist SAIAB Indo-Pacific marine species biogeography – sharing population genetic data Catholic nuns at a small convent in Zambia can take credit for igniting Monica Mwale’s love of science. Mwale, an aquatic biologist with SAIAB, remembers how the nuns at the all-girls school in Livingstone encouraged their pupils to do well in maths and science. It led her to South Africa, where she attained a doctorate in icthyology at Rhodes University in Grahamstown in 2007. ‘They were brilliant teachers and nearly everyone in my class got distinctions in the final maths and science exams,’ she says. Mwale became interested in fish while studying for an agricultural science degree at the University of Zambia. After graduating she applied to study for her Masters degree at Rhodes, later changing focus to fish systematics when out of curiosity she began dissecting pipefish (same family as the seahorse) from SAIAB’s National Fish Collection.

The focus of her research has been on the relationships between fish species, specifically gobies (such as mudskippers) and pipefish living in estuaries of the western Indian Ocean. ‘Very little is known about the evolutionary relationships between the different groups. The questions we are asking are why do they exist in one area but not in another and why have they dominated specific habitats and areas? Why are there so few species of the Syngnathus pipefish genus along the southern African coast when there are as many as 35 in the north Atlantic?’ Her early research into the difference in their biology and genetics was instrumental in the reclassification of South Africa’s pipefish from Syngnathus acus (now their northern hemisphere counterparts) to Syngnathus temminckii. Mwale’s current research is on the genetic structure and phylogeny (family trees) of different fish species. In July 2014, Monica was invited by the team leaders of the international IndoPacific working group, Drs Eric Crandall (Southwest Fisheries Science Center, NOAA Fisheries Service, USA) and Cynthia Riginos (University of Queensland, Australia) to attend a research meeting of the working group at the US National Evolutionary Synthesis Center (NESCent) at Duke University.

When asked what is significant about the invitation for her, Monica said, ‘This collaboration provides an opportunity for me to network and collaborate with toprated researchers in phylogenetics and marine biogeography.

It also affords access to data and opportunities for learning and growth in advanced genetic analyses, for example nextgeneration sequencing. The meeting was therefore a very valuable experience for me and highly relevant for SAIAB. This should encourage international partnerships for future collaboration in the region.’

Noxolo Ntuli processing Seakeys DNA samples in SAIAB’s Collection Management Centre. Image: SAIAB

Yonela Sithole taking morphological measurements of Serranus cabrilla at the South African Museum in Cape Town. Image: SAIAB

The important knock-on advantage of such collaborative opportunities for marine science in South Africa is the chance to develop a better understanding of the evolution of our unique marine fauna and diversification patterns in the Indian Ocean. Envisaged outputs from the collaboration are papers on the biogeography of Indo-Pacific species and the development of electronic and community infrastructure that will facilitate collaboration and cooperation for a greater level of scientific inquiry.

Monica Mwale is also very involved in promoting students and interns in aquatic biodiversity – specifically in genetics and molecular systematics. To this end she is working with 13 co-investigators from nine different South African institutions and departments on the SeaKeys project. The SeaKeys project is managed through the South African National Biodiversity Institute (SANBI) marine programme under Dr Kerry Sink. The project will run over three years and is funded by the National Research Foundation (NRF) through the Foundational Biodiversity Information Programme.

The SAIAB team includes scientists Dr Monica Mwale and Dr Gavin Gouws, BSc Honours student, Yonela Sithole 10| 4 2014

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Mandla Magoro. Image: SAIAB

Mandla Magoro (left) and Ndiviwe Baliwe (right). Image: SAIAB

(Rhodes University), and a DST/ NRF intern based at SAIAB, Noxolo Ntuli.

Up and coming…

Mandla Magoro registered for his MSc at Rhodes University under the supervision of Professor Alan Whitfield. Mandla conducted dietary and fish movement studies on invasive large-mouth bass introduced into the Kowie River in the Eastern Cape Province. Mandla found that these fish prey on certain indigenous estuary-associated fishes in the headwaters of the Kowie Estuary and pose a serious threat to the population integrity and survival of these species.

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Mandla also suggested that the bass may serve as a partial barrier to the upstream migration of juveniles of these estuary-associated fish into riverine nursery areas. This is significant because his study shows that the long-term impacts of introducing alien fishes to natural systems were seldom considered by managers in the past and that the potential negative consequences of such actions need to be investigated before future introductions are undertaken. Mandla will be starting his PhD in 2015.

During 2012, Prof. Whitfield and DST Intern at SAIAB, Ndiviwe Baliwe, compiled a bibliography and review of research trends over a century of science in South African estuaries which was published as a SANCOR Occasional Report: Whitfield AK and Baliwe NG, 2013. A century of science in South African estuaries: Bibliography and review of research trends. SANCOR Occasional Report No.7, 289 pp. Building on this experience, Ndiviwe is now a marine research technician with SANParks.

Athi N Mfikili received his BA (Geography) from Nelson Mandela Metropolitan University, Port Elizabeth, South Africa in 2012. He obtained his Honours in Environmental Management from the University of South Africa in 2014. While he was doing his honours, Athi was doing an internship through DST/NRF at the South African Environmental Observation Network (SAEON), Elwandle Node in Grahamstown, working on coastal wetlands, particularly salt marshes of the southern Cape estuaries.

‘After spending 18 months with SAEON, as GIS intern, I have grown my interest and passion for studying estuarine ecology, salt marshes in particular, studying environmental drivers responsible for the development of salt marshes.

As a result I have decided to register for an MSc with Nelson Mandela Metropolitan University, a programme which is co-funded by SAEON and the African Earth Observatory Network, Inkaba YeAfrika Programme. My MSc research interest is on understanding the influence of sedimentological and hydrological processes on the distribution of salt marshes in the Keurbooms Estuary, Western Cape, South Africa’.

Athi became interested in working with salt marshes after spending almost his entire internship monitoring these systems using GIS tools. Salt marshes are the most productive ecosystems, second after tropical rain forests in biodiversity and biological productivity in the world, yet their survival is threatened by global sea-level rise and anthropogenic activities. Their development and distribution has been closely linked to several environmental conditions, with sediments being particularly important in the face of global sea-level rise. The Keurbooms Estuary in particular lacks well-developed intertidal areas and as a result salt marshes are not extensive. Although the sedimentary environment of the Keurbooms Estuary has drawn some attention over past decades, sediment dynamics of the entire estuary and their influence on the ecosystem of the estuary, particularly salt marshes, are poorly understood. Therefore, this study’s focus is to understand sediment dynamics of the Keurbooms Estuary and how they influence development and distribution of salt marshes in the estuary. Salt marshes develop through sedimentation and in a long-term perspective their existence

Careers

Report, are introduced below: Nonhlanhla (Precotia) Nyalungu is a marine scientist intern at SANParks, with a background in estuaries. Her main interest is estuarine ecology, especially impacts of freshwater reduction in estuaries and determining environmental flows for the ecological functioning of estuaries. Her current research includes invertebrate (prawn) survey and boat survey monitoring. Nomfundo Nkabi is also a marine scientist intern, with a background in freshwater ecology and ecotoxicology. She specialised in freshwater fish histology. Her areas of interest include biology and ecology of marine fish and her current research includes land-based boat monitoring and marine debris monitoring. (SANParks Research Report 2013: http://www. sanparks.org/conservation/reports/research_report.php pp.

68-69). q

Athi Mfikili. Image: SAIAB

depends on continuous sediment supply. Athi’s study will investigate the sediment distribution of the entire estuary to determine sediment properties such as grain size, grain shape, sorting, and organic content. He will also measure sediment deposition of the first intertidal salt marsh, Spartina maritima, to determine sediment received by the system, whether it will be sufficient to ensure the continued existence of salt marshes in the face of global sea-level rise. Because salt marsh distribution and composition is connected to various factors, sediment characteristics such as particle size, moisture content, organic content, and soil salinity will be determined on these vegetation transects.

Vegetation distribution will be complement by GIS mapping of historical and most recent aerial images to determine how the salt marsh distribution has changed overtime.

Athi says about his future goal in the environmental sector, ‘Having a background in both natural and social sciences makes me fit well in the environmental biodiversity sector and SAEON was critical in providing a platform to put those two sciences into practice through their environmental education outreach. I am prepared to build a solid career in the environmental sector where I would merge social and natural environmental elements together, because I strongly believe that natural sciences alone cannot yield their intended goals without engaging the humans to whom these areas belong and in which they interact with the natural environment. So ... I want to make a contribution in bringing the natural science sector of the environment closer to the social sector, to make both parties understand their relationship’.

Two other interns who have been through SAIAB, and are also featured as contributors to the 2013 SANParks Research

Penny Haworth is Manager of Communications & Governance at the South African Institute for Aquatic Biodiversity (SAIAB) in Grahamstown. Penny has many years' experience in communication having worked as an environmental and museum educator, educational resources manager, museum display artist, English teacher, events manager and publications officer. She also presents workshops on creative writing. Her most recent achievement was receiving the South African Network for Coastal and Oceanic Research Communicator Award 2014 in recognition of her role in communicating marine science at a local and national level.

Postgraduate Opportunities at SAIAB  Specialist postgraduate supervision As a National Facility SAIAB can offer supervision to students from universities throughout South Africa.

 Postdoctoral research fellowships

Research fellowships are offered through the NRF Professional Development Programme.

 ACEP Phuhlisa Programme

This is a strategic initiative that aims to promote postgraduate studies in marine science at Historically Black Universities to accelerate transformation in the marine science research community.

 Postgraduate internships

Interns experience the full spectrum of scientific research from work in our state-ofthe-art laboratories and fieldtrips to exotic locations, to presenting scientific papers at conferences and symposia under the wing of their supervisor, preparing them for a career in scientific research.

Contact us: Tel +27 (0)46 6035800 Fax +27 (0)46 6222403 email saiab@saiab.ac.za web http://www.saiab.ac.za

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Radio telescopes unravel mystery of nova gamma rays

The early stage of the classical nova explosion. Image: Image courtesy of Bill Saxton: National Science Foundation, Associated Universities, Inc and the National Science Foundation

The fast-moving polar flow meets the flow from the equatorial region.

Image courtesy of Bill Saxton: National Science Foundation, Associated Universities, Inc and the National Science Foundation

Towards the end of the process, everything detaches from the binary system.

Image courtesy of Bill Saxton: National Science Foundation, Associated Universities, Inc and the National Science Foundation

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Highly detailed radio-telescope images have pinpointed the locations where a stellar explosion called a classical nova emitted gamma rays, the highest-energy form of electromagnetic waves.

The discovery revealed a probable mechanism for the gamma-ray emissions, which mystified astronomers when they were first observed.

‘We not only found where the gamma rays came from, but also got a look at a previously unseen scenario that may be common in other nova explosions,’ said Assistant Professor Laura Chomiuk of Michigan State University in the United States of America, lead author of the paper that has just been published in the scientific journal, Nature.

Assistant Professor Chomiuk worked with an international team of astronomers, including Dr Valério Ribeiro, a Square Kilometre Array (SKA) fellow at the University of Cape Town’s Department of Astronomy. Dr Ribeiro played a crucial role in the interpretation of the results. He had modelled the system previously in a paper published in The Astrophysical Journal, and Assistant Professor Chomiuk’s team called on him to provide insight into his models and to see how these compared with the radio observations.

A classical nova is a single occurrence of a nuclear explosion on a white dwarf, a very dense remnant of a star.

When a white dwarf orbits in close proximity to another star, its extreme gravity can pull hydrogen from the nearby star onto itself. This causes an increase in pressure and temperature that eventually triggers a thermonuclear explosion, which blows debris into space.

Astronomers did not expect this process to produce high-energy gamma rays, which are usually produced by the hottest and most energetic objects in the universe (the sun, for instance, also produces gamma rays, but right in the core, where the temperatures are extreme). However, in June 2012, the US National Aeronautics and Space Administration’s Fermi spacecraft detected gamma rays coming from a nova called V959 Mon, some 6 500 lightyears from Earth.

‘Nova eruptions are the most common Galactic explosions,’ says Dr Ribeiro. ‘This particular explosion was very interesting; because it was the first to produce gamma-ray emissions, there was a lot of interest in understanding its parameters.’

Dr Ribeiro was one of the first astronomers to model the V959 Mon nova in order to determine its shape more accurately.

‘Radio wavelengths are ideal for measuring the basic parameters of these explosions, such as their mass and how energetic the explosion was,’ he says. ‘However, many of the models applied to date have been assuming that the geometry of these explosions was spherical, since this is the easiest approximation.’

Dr Ribeiro’s models, however, discovered that the eruption had a bipolar shape similar to a dumb-bell. This has contributed significantly to a better understanding of the process.

When the nova first erupts, the force of the explosion

❚❚❚❙❙❙❘❘❘ News

Left: In the initial explosion, the nova envelope (the nuclear explosion that encompasses the white dwarf and its nearby companion) expands (the light yellow area). This interacts with the binary system, which you can see right in the middle: a star and a little circle, showing the orbit. The effect is that material in the equatorial region (dark yellow, going vertically in the image) becomes much more dense.

Middle: The dense material (now in yellow) starts moving at a slower velocity, as the material coming out of the poles moves at a much faster velocity (now in blue). This is because there is not much interaction at the poles, so the material can flow smoothly.

This difference in velocity is what produces the shocks (orange

causes the white dwarf and the nearby star to lose some of their orbital energy. This propels the ejected matter even faster, out into the plane of their orbit. Later, the white dwarf blows off a faster wind of particles along the poles of the orbital plane. When the faster-moving polar flow hits the slower-moving material at the equatorial region, the shock accelerates particles to the speeds – close to the speed of light – that produce the gamma rays.

Since the observation of the V959 Mon nova, Fermi has detected gamma rays from three further nova explosions.

‘This mechanism may be common to such systems. The reason the gamma rays were first seen in V959 Mon is because it’s close,’ says Assistant Professor Chomiuk.

However, when the South Africa MeerKAT radio telescope (the precursor to the SKA telescope) starts observing the sky, the radio models Dr Ribeiro developed as a SKA fellow at UCT will be very useful: ‘We should start finding a number of these nova explosions,’ he says, ‘and this will undoubtedly open up a whole new set of questions to ask, as this Nature paper does’.

The advent of the SKA telescope should increase our understanding even further. ‘Once the SKA comes online,’

lines), and the red blobs depict the shocks in the radio emission.

The reason we don’t see these shocks in other regions is because they are embedded within the ejecta, which is opaque (in the same way that you cannot see through a dense cloud).

Right: At this point the wind from the white dwarf ceases, and everything detaches from the binary system as it flows outward and rapidly drops in density. The blue region will drop in density much faster than the yellow region, which will dominate radio images for much longer.

Image courtesy of Bill Saxton: National Science Foundation, Associated Universities, Inc and the National Science Foundation

explains Dr Ribeiro, ‘we will have the sensitivity and resolving power to observe more of these systems directly at further distances, allowing us to start exploring these systems – not just as individuals, but as populations’.

Dr Ribeiro himself, meanwhile, has just taken up a prestigious position as a Radboud Excellence Fellow at Radboud University in the Netherlands, a fellowship awarded to exceptionally talented young researchers. This is just another step on the trajectory for Dr Ribeiro, who is a living example of SKA’s intent to nurture African talent and prepare it for future leadership roles in SKA science.

Dr Ribeiro has been involved in capacity development himself, teaching introductory courses in astrophysics at the University Eduardo Mondlane in his home country of Mozambique, a SKA partner country. Dr Ribeiro is still closely linked to the UCT team and hopes to return to southern Africa in time for the start of the MeerKAT/ SKA era: ‘The SKA fellowship allowed me to be part of a vibrant and rapidly changing environment, as well as to build lasting relationships with the South African astronomy community’.

Issued by: UCT Communication and Marketing Department.

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Phone: +27 12 343 58 29 • Fax: + 27 12 343 02 87 e-mail: info@inqababiotec.co.za • www.inqababiotec.co.za

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An industrial diamond used in an anvil impactor.

Image: R Tanaka via Wikimedia Commons

It all started with diamonds Lucy Stone explains South Africa’s collaboration with a key international facility.

8 000 km away in the south-eastern corner of France rests what looks like, on first glance in an aerial photograph, a rather impressive football stadium.

It is circular, about the size of a sports ground and gleams more brightly than its surroundings, especially at dusk. While Grenoble does have an impressive arena, this particular ‘stadium’ is actually the most powerful ‘microscope’ of its kind in Europe. Inside, instead of finding footballers or rugby players running at 32 kilometres per hour, you will discover electrons circulating at a pace near to the speed of light.

The speed of light is a universal physical constant.

Its value is exactly 299 792 458 m per second.

The length of a metre is defined from this constant, as is the international standard for time.

The European Synchrotron Radiation Facility (ESRF) is an X-ray light source, a synchrotron, used by thousands of scientists each year to study everything from giant shrimp sperm (yes, that’s right) to looking at the biophysical properties of elements such as copper, which have been demonstrated to have a role in the development 28

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of Parkinson’s disease. Inside the facility, electrons are accelerated and then circulated in an 844 m ring; they give off light in the form of thin X-ray beams that are about the width of a human hair. The X-ray light is fed into laboratories known as experimental stations, or beamlines, and used to study scientists’ samples with a range of techniques. More than 40 of these stations are positioned around the ring, each offering different set-ups of instruments to look at a variety of samples under different conditions.

The significance of this for South Africa is that this facility, which has hosted 90 000 users and contributed to 25 000 publications and three Nobel Prizes, is available for use by scientists within the country, for free, with all the access-related expenses paid.

South Africa is one of two countries outside Europe to have such access to this facility, the most productive synchrotron in the world. In return, the ESRF benefits from a wealth of expertise from South African scientists. In fact, there are many ways in which the ESRF and South Africa are working together.

South Africa and the European Synchrotron It was in May 2013 that researchers in South Africa gained

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An aerial photograph of the European Synchrotron outside Grenoble. Image: ESRF/G Adams

the same rights as users from European ESRF member states, that is, scientists do not have to pay to use the facility, and their travel, food and accommodation expenses are also covered. South Africa’s National Research Foundation (NRF) signed a deal that is valid until the end of 2017 that gives South Africa a 0.3% share in the facility.

At the time, Dr Albert van Jaarsveld, CEO of the NRF, said: ‘This is a remarkable achievement, and it recognises the excellence of our local scientists as well as the global research opportunities that can be accessed from South Africa’.

Francesco Sette, Director General of the ESRF, said: ‘I’m delighted to welcome South African scientists to the ESRF and look forward to further developing common research programmes and opportunities’.

Although this expenses-paid access to the ESRF is a new arrangement, collaboration between South Africa and the synchrotron goes back a long way. In fact, it stretches back to the preparation of operations at the ESRF. It started with…a diamond For centuries, diamonds have been a symbol of a sealed relationship. Ever since 1477 when the first welldocumented example of an occasion in which a diamond ring was given at a ceremony to seal a commitment, they have symbolised long-term partnerships. In the case of the ESRF and South Africa, however, it was with diamonds that the relationship began.

‘Back in the 1990s, one source for getting industrial diamonds was South Africa’, recounts Andy Gotz, the Head of the Software Group at the ESRF and a South African who graduated from Rhodes University, Grahamstown. ‘I

remember them being brought over. We used them mainly for monochromators and there was only one company in South Africa that supplied them. It worked well because we needed the diamonds for our instruments and they needed their diamonds characterised’.

In fact it was as early as 1989 that the first ESRF-South Africa contact was established and fruitful collaboration began. This was when the idea of using diamonds as X-ray optical elements at modern synchrotron sources first appeared. The concept was presented at the ‘Workshop on High Heat Load X-ray optics’ at the Argonne National Laboratory. Following that, in 1992, co-operation between the ESRF optics group and the University of the Witwatersrand (Wits) began, and later with the University of Johannesburg.

In 1994 the first research on diamond surfaces using synchrotron light began, with experiments from both Jacques Pierre Friederich Sellschop and Trevor Derry.

The focus was soon dominated by the joint quest for the ‘perfect diamond’. In the collaboration, the South Africans concentrated on synthesis and processing while the ESRF shared its expertise in studying crystals using X-ray diffraction. This allowed crystal growers and processors to improve their technology and in turn ESRF benefited from having crystals with a sufficient quality to be used on the beamlines. It led to collaboration with South African companies De Beers and later, Element Six – they made the best synthetic diamonds, exactly what ESRF needed.

These early interactions expanded to other thematic areas and led to the emergence of the South African light source community which has continued to grow and has seen effective results, noticeably in palaeontology, 10| 4 2014

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The two fossils. Image: ESRF/V Fernandez

Comparison of results from a traditional laboratory microtomograph and X-ray images obtained at the ESRF. Image: ESRF/V Fernandez

paleoanthropology, materials science and macromolecular crystallography.

Collaborative research – telescopes, fossilised burrows and an ancient skeleton As a result of the early work on diamonds, more and more strands of collaboration between the ESRF and South Africa started to develop and many still exist. In 1991, Andy Gotz was part of a team that developed a software package known as TACO to control ESRF’s accelerator. In 1995, during a year in South Africa, he tailored the system for the telescope at the Hartebeesthoek Radio Astronomy Observatory. The software is still used within the telescope today.

There are a number of current South African-ESRF joint projects, some a continuation of the early diamond work, and others which have developed more recently. One of the key areas of mutually beneficial collaboration is in the field of palaeontology. South Africa has a rich source of palaeontological specimens and ESRF has the cutting-edge technology to scan them.

In particular, collaborations between the Evolutionary Studies Institute (ESI) at Wits and the palaeontology community at the ESRF have strengthened over time.

Scientists at the ESI have had two proposals to study 30

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fossilised burrow casts accepted. The first led to an experiment performed in July 2011 which resulted in several published papers as well as student projects.

The burrow project is studying how a group of animals named therapsids, adapted to life underground to survive in extremely harsh environments. Therapsids were the forerunners to mammals – also known as mammal-like reptiles. Their fossils have been preserved in abundance in rock in the Karoo (see left). They were the dominant creatures on land at the end of the Paleozic era and especially during the Permian period (300 - 252 million years ago). At the end of this era the most dramatic extinction event yet experienced occurred, wiping out about 70% of all terrestrial species. In South Africa, where the fossil record is one of the best in the world to study the existence of creatures during this period, research shows the sudden onset of a harsh climate. It appears that those who survived may have done so because they were able to adapt to an underground existence.

‘The problem is’, said Vincent Fernandez from the ESRF who has been working on the project with his collaborators Bruce Rubidge, Kristian Carlson and Fernando Adbala, ‘because the burrow casts preserve the impressions of scratch marks made by the digging creatures, palaeontologists have been reluctant to crack open the casts to look for bones of the inhabitants of the burrows as it could destroy the evidence of the digging technique’.

The advent of X-ray microtomography has partially solved this problem – there is a Microfocus X-ray Computed Tomography facility at Wits that can detect the presence of fossil bones in a non-destructive way.

Once promising samples have been found, the much more powerful synchrotron-based microtomography at the ESRF can be motivated. This has allowed the creation of detailed 3D volumetric images where skeletons can be virtually removed from their tomb. The beamlines ID17 and ID19 in particular offer a unique combination of high-resolution, high-flux, near-laser quality beams of highly energetic X-rays where the beam span is wide enough to image the entire structure. Furthermore, a vastly more powerful quantitative imaging technique based on extracting the changes in the phase of the X-ray waves can be used. The combination of these techniques has enabled the production of scans with a quality achieved nowhere else in the world (see comparison left).

Blair McPhee from ESI, who transported the borrow containing the creature, said of his visit to the ESRF: ‘It was an amazing experience and a very welcome opportunity.

It was truly impressive to see first-hand the scope and the scale of the synchrotron itself and of the research being conducted there’.

Other work on therapsids has included looking at whether dental replacement in pre-mammal fossil species is similar to that of most living mammals, or represented by multiple replacements during their life, like reptiles. Fernando Abdala and his collaborators scanned five different specimens from around 252 million years ago and found that in all specimens post-canine teeth were replaced by waves of odd and even growing teeth, as found in modern reptiles.

Abdala said: ‘Access to non-destructive imaging techniques

Composite reconstruction of A. sediba based on recovered material from MH1, MH2 and MH4 and based upon the most up-to-date research. As all individuals recovered to date are approximately the same size, size correction was not necessary.

Femoral length was established by digitally measuring a complete femur of MH1 still encased in rock. For comparison, small-bodied female modern H. sapiens on left, male chimpanzee (Pan troglodytes) on right. Image: Lee Berger, courtesy of the University of the Witwatersrand

at the ESRF will allow the extension of these studies to more primitive forms, which will allow us to understand variation of dental replacement during the transition to mammals’.

Another key result relating to collaboration between ESRF and South Africa is with respect to the skeleton of an early human ancestor. Again using ESRF’s ID17 and ID19 beamlines, scientists were able to study the brain cavities of Australopithecus sebida fossils that are almost 2 million years old. The results helped to clarify the debate concerning the gradual increase of brain volume in human ancestry following the transition from Australopithecus to Homo species. The benefits overall are the combination of the high-quality specimens and knowledge of the topic from South Africa and the cutting-edge techniques and wealth of palaeontology experience at the ESRF. Working together to tackle disease A major priority for South Africa and for researchers across the world is the study of diseases such as malaria, viruses such as HIV and the development of drugs to treat serious medical problems. The ESRF has been offering a number of opportunities for PhD students and trainees to study diseases and viruses of this kind. Students are given the chance to spend some of their time in Grenoble and some in South Africa. In South Africa the students learn from the experts in disease and in Grenoble they understand the techniques available to study them.

Jennifer Channell is doing a joint PhD between the Life Science Group of the Institut Laue-Langevin (ILL) and the Business Development Office of the ESRF. Her awarding institution is Keele University in the UK. Her project is in collaboration with the HIV Pathogenesis Research Laboratory within the Department of Molecular Medicine and Haematology at Wits Medical School, where she is currently based. Jennifer will spend the first three months of her PhD in South Africa before continuing her studies in Grenoble. She said: ‘Working with people who have done a lot of research into HIV and then being able to bring that knowledge back to Grenoble where there’s an expertise in structural biology means you have the best of both worlds.

The experience of working in South Africa has also been very interesting culturally – I am meeting people from lots of different countries’.

Meanwhile, Sarah Waldie, from the University of Bath, in the UK, is on a ten-month placement working on the same project, but based in Grenoble. She said: ‘The scale of the ESRF is really big and so different to working in a lab at university. I like being part of a project where I am speaking to people in South Africa on a weekly basis and feel like I am contributing to a much broader picture’.

Vinesh Jugnarain spent ten weeks as a trainee at the ESRF earlier this year on the international internship summer programme. He is now in the second year of his MSc at Wits and his work is dedicated to HIV research and therapeutics.

The reconstructed skull and mandible of Australopithecus sediba.

Image: Reconstruction by Peter Schmid, photo by Lee Berger courtesy of the University of the Witwatersrand

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Physics

He is hoping to return to the ESRF. He said: ‘This was my first time in France, and Europe in general. As well as being impressed with the country on its own, the ESRF was undoubtedly a setup that I could have hardly imagined. The infrastructure and technology were on another scale, and there was much to learn and re-think. The experience at the ILL and ESRF allowed me to have an apercu of science elsewhere than what I have known until now in South Africa. Certainly, it allowed an exchange of ideas, which is critical for the advancement of science in South Africa.

From here, I hope that this initial step leads on to long-term collaboration for future student exchanges’.

Another ESRF-South Africa collaboration with a focus on healthcare is work carried out by Wolf-Dieter Schubert from the University of Pretoria. Schubert has been looking at the molecular basis of infectious diseases and in particular bacterial diseases. Escherichia coli and Salmonella spp., are among those to be studied. ‘Understanding protein-protein interactions allows us to manipulate or fine tune such interactions to help in creating molecular tools to investigate the particular signalling or metabolic pathway that the pathogen targets. This allows us and others to arrive at a more fundamental understanding of the processes working within the human cell and in the entire body’.

Industrial partnerships For the industrial collaborations between the ESRF and South Africa we return to the topic of diamonds. In the early 2000s a partnership was established between Element Six technologies (Johannesburg, South Africa), the University of Johannesburg and the ESRF. The aim was to co-ordinate and focus efforts to develop diamond-based X-ray optical elements for premier X-ray sources and at the same time advance the study, synthesis and processing of near-perfect diamonds. The optical elements that resulted from this industrial research and development are now regular features in high-energy synchrotrons worldwide and X-ray Free Electron Lasers (XFELS). Recently this programme has broadened to include more international partners in the quest for a diamond-based crystal undulator, a device that could conceivably lead to lasing in the gamma ray regime.

Another key industrial partnership between the ESRF and South Africa is the one with SASOL, an international integrated energy and chemical company that develops and commercialises new technologies to produce liquid fuels, high-value chemicals and low-carbon energy. The company funds South African chemistry and engineering students, some of whom work with the ESRF. Esna du Plessis, Principal Scientist from SASOL Technology, gives her take on the collaboration: ‘The scientific excellence, synchrotron schools and user group meetings at the ESRF motivate researchers to use the facilities. The South African partnership with the ESRF recognises the excellence of South African researchers and showcases the National Research Foundation’s commitment to science in South Africa. This partnership will build human capital and research capacity for sustainable growth and development in South Africa. The students coming to the ESRF benefit from academic beamtime not only by obtaining high-quality data for their research, but also 32

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through networking with world-class researchers at these facilities. Conferences, user group meetings and synchrotron schools provide opportunities to share their results and grow their knowledge’.

What’s next?

The success of the current partnerships between South Africa and the ESRF is clear to see. here are a number of collaborations, too many to cover in the scope of this article, that are working well.

‘The collaboration means that South Africans get access to a premier global research centre which can take existing research projects to the next level with respect to the quality and quantity of data and entirely new measurements’, said Simon Connell, a Professor from the Department of Physics at the University of Johannesburg. ‘As well as access to premier research facilities, students also get exposure to peers and mentors from the broader collaborations.

The boost to our local research programme also enables more successful proposals for the development of local infrastructure’.

In turn, Professor Connell said, ‘The ESRF has an improved opportunity to collaborate with excellent South African scientists. It is important for science to be a global enterprise, and participation from the African contingent is a very significant part of this. South Africa has strong links with African scientists and can act as a catalyst for the increasing participation by Africa’.

Jürgen Härtwig, Head of the ESRF crystal laboratory, said: ‘It really is a co-operation with a mutual interest with scientific and technical exchange and one that continues to thrive. Right now for example, we are setting up an X-ray Laboratory at the University of Johannesburg which will have two sophisticated instruments for two different techniques of X-ray topography’.

Harald Reichert, ESRF’s Director of Research said: ‘We hope to continue to build on these already significant collaborations with South Africa. We would like to build up more networks in the country, with a view to both further strengthening the existing partnerships we have, and creating new ones. We look forward to progressing this aspect of the collaboration in the near future’.

So with a new X-ray laboratory on the way in South Africa and discussions underway for South Africa to have a beamline at an international facility, it looks like the partnership that started 25 years ago, is set to continue.

After all… diamonds are forever. Q To apply for beamtime at the ESRF see the following link: http://www.esrf.eu/UsersAndScience/UserGuide/Applying

Lucy Stone is Communications Manager at the ESRF. After spending five years at the Science and Technology Facilities Council in the UK, based at the Rutherford Appleton Laboratory she moved to Grenoble in France to take up a position of Communications Manager. Prior to her time at the Rutherford Appleton Laboratory, Lucy was a radio journalist working both as a news and sports reporter. In her spare time Lucy enjoys football matches; she supports Portsmouth Football Club in the UK but while living in Grenoble will be going along to the occasional Grenoble football match there. Living in the ‘capital of the Alps’, she is increasingly enjoying hiking and plans to try skiing when the winter rolls in.

❚❚❚❙❙❙❘❘❘ News

Aardwolves select their

termite diet carefully From aardwolves to whales.

Nicolize Mulder highlights new research at the University of Pretoria.

W

hat do aardwolves and whales have in common? Both are extremely picky eaters and tend to eat only one thing. Whales prefer a particular type of plankton, and aardwolves have their favourite termites. Both species will eat less rather than diversify their menus.

The highly selective diet of the aardwolf was one of Dr Low de Vries’ main research findings. De Vries, from the University of Pretoria’s Institute for Mammal Research, studied this smallest member of the Hyaenidae family for six years and has completed the most comprehensive study to date on the diet and home range of the aardwolf.

De Vries graduated with a doctorate in zoology from the University of Pretoria in September. But he did not attend the ceremony, as he is fulfilling a long-held dream of spending a year as part of South Africa’s annual research team on Marion Island. Here he will be studying the ecology and population dynamics of elephant seals, two species of fur seals and killer whales.

However, De Vries’ PhD research took him to the Benfontein Nature Reserve near Kimberley in the Northern Cape, where he studied termites and ants and collected aardwolf scat to examine in the laboratory.

‘In theory, aardwolves are too large an animal to be able to sustain themselves on termites alone, but I have found that the abundance of termites dictates many aspects of their ecology,’ he notes. ‘Few other mammals are as highly specialised and selective in their diet as the aardwolf.’

De Vries is the first to show that aardwolves also occasionally eat scorpions or the large solifugids or camel spiders. However, he found that aardwolves still rely almost completely on termites (Trinervitermes trinervoides) for sustenance. They do not readily switch to other prey, even in times when termite numbers are low.

‘Aardwolves are capable of feeding on a much larger variety of prey than previously thought, if they wanted to,’ he explains. ‘However, instead of incorporating more types of prey into their diets during the dry months when termite numbers are low, they lower their metabolic rate and can lose up to 20% of their body mass.’

Aardwolves are only found in areas where termites occur. ‘The general size of an aardwolf’s home range is actually larger than would be expected for an animal of its size, possibly to ensure that there’s enough of its food source available or to ensure adequate mating opportunities,’ De Vries suggests.

De Vries says that the more termite mounds there are in an area – irrespective of their size – the smaller the animal’s home range tends to be.

‘Aardwolf home ranges will vary across South Africa, depending on the abundance of termites,’ predicts De Vries, who also found that aardwolves are quite neighbourly and allow home ranges to overlap.

Males also tend to share dens. This is contrary to previous research from the 1980s that showed that aardwolves can be quite aggressive towards neighbours from adjacent home ranges.

Through his research De Vries also made interesting findings about the insects, spiders and scorpions that live in arid regions. He noted how temperature rather than rainfall has a bigger influence on their abundance and the diversity – quite the reverse from influences in habitats such as forests. This dependence on temperature is particularly important for species such as the aardwolf, bat-eared fox and yellow mongoose, which rely almost entirely on these arthropods as their main food source, since these arid areas of South Africa are likely to experience higher temperatures and less rainfall over the coming decades.

‘Aardwolves and other insectivorous animals might face a decrease in food availability due to climate change, which might influence their distribution and survival,’ predicts De Vries.

Issued by the University of Pretoria

Young aardwolf on a termite mound. Image: Philip Richardson

Adult aardwolf. Image: Low de Vries

Dr Low de Vries doing research on the Benfontein Nature Reserve in the Northern Cape.

Image: Fred Dalerum

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Mass vaccination

can keep this neglected disease under control Mass dog vaccination campaigns can have a substantial impact on keeping rabies under control. By Michelle Galloway.

M

ass vaccination campaigns that reach 70% of dogs will control and, hopefully, eventually eliminate rabies. This is the message that Prof. Darryn Knobel of the Faculty of Veterinary Science at the University of Pretoria would like us to hear.

Anyone who has a dog knows they must be vaccinated regularly against rabies – both to keep the dog and the human family healthy. Not only is it essential for public health but it is also a legal requirement. Of course, this is more challenging in disadvantaged communities where there may not be money for expensive veterinary services, and this is where the state steps in with mass vaccination campaigns. Prof. Knobel’s work in the Hluvukani settlement in Bushbuckridge in Mpumalanga has shown that if the government can achieve a 70% coverage rate in annual mass vaccination campaigns in such areas, we will achieve herd immunity and keep the incidence of rabies down.

‘There is clear evidence that 70% is sufficient and do-able and that this target would have a substantial impact on rabies control,’ explains Prof. Knobel. ‘This was found even in a very dynamic dog population where there is both a high annual birth and death rate.’

Although rabies vaccines have been around for many years, no vaccine for any disease is completely protective. What you want to achieve is enough coverage in the population (animal or human) to reduce the amount of virus in circulation – this is called herd immunity and is the goal in vaccination campaigns. The magic threshold of coverage needed to achieve such immunity varies by virus but is fairly moderate for rabies – estimated at about 40%. However, in a community with a high turnover in the dog population (due to deaths and births) it’s hard to keep the level of vaccinated dogs consistent, so higher coverage is required to maintain herd immunity until the next campaign.

‘Between campaigns, the proportion of immune individuals in the population declines as vaccinated dogs die and susceptible dogs enter the population through birth or migration,’ says Prof.

Knobel.

‘The World Health Organisation recommends 70% coverage but there was little theoretical and empirical evidence to support this percentage, especially in less-advantaged areas,’ explains Prof.

Knobel.

‘Our work in Bushbuckridge has confirmed that this is the appropriate and required level of coverage,’ he continues.

Dogs in disadvantaged, rural communities are often free roaming, increasing their risk of rabies. However, there is a misconception that they are not owned. Prof. Knobel’s research has shown that this is not necessarily the case.

‘There was no evidence of a large-scale, un-owned dog population,’ says Prof. Knobel. ‘More than 90% of the dogs are owned which means they are accessible for vaccination.’

Rabies is one of the oldest infectious diseases known to man, but is classified as a neglected tropical disease. Rabies is caused by infection with strains of Lyssavirus in the family Rhabdoviridae.

Rabies can be found in any mammals but two main strains occur in Africa – one in the dog population, and one in mongooses.

Globally the dog strain is the most prevalent and the most likely to be transmitted to humans. Over 90% of human cases in Africa are attributed to dog bites. Around 10 - 30 human cases of rabies are confirmed each year in South Africa, and result almost exclusively from dog bites. However, it is likely that this number is underreported, particularly in remote rural areas.

In another study, Prof. Knobel has reviewed work done on rabies

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in wildlife in Africa. Surveillance in the Serengeti and Kruger Parks and elsewhere has shown that, despite its presence in adjacent dog populations, rabies is not a significant conservation concern for wildlife in Africa. However, where it does occur, it seems to be most likely in small, vulnerable populations, such as African wild dogs and Ethiopian wolves. Controlling the disease in domestic dog populations through wide-scale mass vaccination would therefore be an important component of protecting and conserving these species as well. Prof. Knobel’s work also points to the importance of ongoing surveillance for rabies in wildlife populations. ‘There is a need to maintain and intensify rabies surveillance in wildlife alongside efforts to control the disease in dogs,’ he says.

Prof. Knobel presented this work at the 39th World Small Animal Veterinary Association Congress in Cape Town (16 – 19 September 2014). He also launched a small project at the congress where attendees were encouraged to donate their conference name-badge holders to be turned into dog collars which will be used to identify (and therefore track) dogs in the study community. The collars would also provide a visible sign of dog ownership in the community. More details on this project can be found at http://www2.kenes.com/ wsava/congress/Pages/AccompanyingProgram.aspx Issued by the University of Pretoria.

Prof. Darryn Knobel. Image: UP

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Rabies facts Adapted from the National Institute of Communicable Diseases website – http://www.nicd.ac.za/

What is rabies?

Rabies is a preventable viral disease. The virus infects the central nervous system and brain. There is no effective treatment and once symptoms start, death is almost inevitable. The virus is transmitted from infected animals to humans through scratches, bites, or licks on mucous membranes. The virus cannot be transmitted through intact skin. Many other animals can transmit rabies including cats, cattle, bats and mongooses.

How can rabies be prevented?

Vaccinate your pets: Dogs and cats should be regularly vaccinated against rabies – it is a legal requirement. Dogs and cats should be given vaccine at three months, a booster within the following nine months, and every three years thereafter. In high-risk areas, yearly vaccinations are recommended.

Avoid being bitten: Not every bite poses a risk, but a bite or scratch from a stray animal, sick animal, an animal that is behaving strangely, or an unprovoked attack would be risky. Over 90% of human cases in Africa are linked to dog bites.

Rabies is fatal if not treated early and it reaches the central nervous system. It is important to receive treatment before clinical symptoms develop.

If exposed to a suspected rabid animal: n Wash the wound. n Seek treatment: Rabies can be prevented if preventative treatment (post-exposure prophylaxis) is given immediately.

This includes vaccination and, in more severe instances, injection of immunoglobulin into the wounds.

What are the signs and symptoms?

In humans: The first symptoms are flu-like, including fever, headache and fatigue, which then progresses to involve the respiratory, gastrointestinal and/or central nervous systems.

There is progressive paralysis, followed by coma. Death occurs within seven days.

In animals: Rabid animals behave abnormally – showing lack of fear, aggression, disorientation, paralysis, and excessive salivation. However, an infectious rabid animal could appear healthy for a period of time prior to the onset of clinical rabies.

Who is at risk?

People who live in rural areas where access to health care and animal health facilities is limited, stray dogs are more common and fewer pets are vaccinated, are most at risk. Children are

Distinct terrains on Rosetta’s Comet This view of the ‘belly’ and part of the ‘head’ of comet 67P/ Churyumov-Gerasimenko indicates several morphologically different regions. (Rosetta is a robotic space probe built and launched by the European Space Agency to perform a detailed study of comet 67P/ Churyumov–Gerasimenko.)

Scientists have analysed images of the comet’s surface taken

by OSIRIS, Rosetta’s scientific imaging system, and defined several different regions, each of which has a distinctive physical appearance. This analysis provides the basis for a detailed scientific description of 67P’s surface.

The comet has areas dominated by cliffs, depressions, craters, boulders and even parallel grooves. While some of these areas appear to be quiet, others seem to be shaped by the comet’s activity, in which grains emitted from below the surface fall back to the ground in the nearby area.

As both comet 67P and Rosetta travel closer to the sun during the next few months, the OSIRIS team and other instruments on the payload will monitor the surface to look for changes. While scientists do not expect the borderlines they have identified for the comet’s various regions to vary dramatically, even subtle transformations of the surface may help to explain how cometary activity created such a breathtaking world.

TEM micrograph with numerous rabies virions (small, dark grey, rodlike particles) and Negri bodies (the larger pathognomonic cellular inclusions of rabies infection).

Image: Centers for Disease Control, Wikimedia Commons

at the highest risk of dog rabies; 30 to 60% of dog-bite victims are children under 15 years of age. In areas known for rabies, people with frequent exposure to animals (e.g. veterinarians or animal health workers, wildlife specialists or researchers) are also at high risk.

Is there immunisation against rabies?

There is an effective, safe vaccine against rabies. People at higher risk of exposure should consider vaccination, including travellers visiting remote areas. Although vaccination does not eliminate the need for therapy after a rabies exposure, it simplifies management.

❚❚❚❙❙❙❘❘❘ News The Rosetta surface.

Image: ESA/Rosetta/MPS for OSIRIS Team/ MPS/UPD/LAM/IAA/SSO/INTA/UPM

Source: NASA

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News

Earliest modern human sequenced A research team led by Svante Pääbo, Bence Viola and Janet Kelso of the Max Planck Institute for Evolutionary Anthropology (Leipzig, Germany), with participation of UCT researcher Domingo García, has sequenced the genome of a 45 000-year-old modern human male from western Siberia. The comparison of his genome to the genomes of people that lived later in Europe and Asia shows that he lived close in time to when the ancestors of present-day people in Europe and eastern Asia went different ways. Like all presentday people outside Africa the Ust’-Ishim man carried segments of Neanderthal DNA in his genome. But these segments were much longer than the ones found in present-day humans and indicate that the admixture with Neanderthals took place between 50 000 and 60 000 years ago.

Its diet shows higher environment plasticity, different to what is directly observed on Neanderthals.

In 2008, a relatively complete human femur was discovered on the banks of the river Irtysh near the village of Ust’-Ishim in western Siberia. Radiocarbon dating of the bone showed it to be about 45 000 years old. ‘The morphology of the bone suggests that it is an early modern human, that is an individual related to populations that are the direct ancestors of people alive today’ says Bence Viola, an archaeologist who analysed it. ‘This individual is one of the oldest modern humans found outside the Middle East and Africa’ he says.

The research team sequenced this individual’s genome and compared it to the genomes of present-day humans from more than 50 populations. They found that the Ust’-Ishim bone comes from a male individual who is more related to presentday people outside Africa than to Africans, showing that he is an early representative of the modern population that left Africa.

When his genome was compared with people outside Africa, he was found to be approximately equally related to Stone Age peoples in East Asia and Europe. ‘The population to which the Ust’-Ishim individual belonged may have split from the ancestors of present-day West Eurasian and East Eurasian populations before, or at about the same time, when these two first split from each other’, says Svante Pääbo. ‘It is very satisfying that we now have a good genome not only from Neanderthals and Denisovans, but also from a very early modern human’ he says. Palaeoanthropologist Jean-Jacques Hublin, who was involved in the study, says that ‘it is possible that the Ust’-Ishim individual belonged to a population of early migrants into Europe and Central Asia, who failed to leave descendants among present-

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The fragment of the human femur found near Ust’-Ishim. Image: UCT

Domingo García of the Department of Archaeology, UCT. Image: UCT

day populations’.

Since the Ust’-Ishim man lived at a time when Neanderthals were still present in Eurasia, the researchers were interested in seeing whether his ancestors had already mixed with Neanderthals.

They found that about 2% of his DNA came from Neanderthals – similar to the proportion found in present-day East Asians and Europeans. However, the Neanderthal DNA segments in his genome are much longer than the ones found in present-day humans, because he lived closer in time to the admixture event so that the Neanderthal segments had not had time to become as reduced in size over the generations. ‘This allowed us to estimate that the ancestors of the Ust’Ishim individual mixed with Neanderthals approximately about 7 000 to 13 000 years before this individual lived, or about 50 000 to 60 000 years ago, which is close to the time of the major expansion of modern humans out of Africa and the Middle East’, says Janet Kelso, who led the computer-based analyses of the genome.

Stable isotope analysis of this early modern human suggests that he consumed freshwater resources on a regular basis, something yet to be directly observed on Neanderthals.

‘These results are important, since

the consumption of aquatic resources portrays a wide-spectrum dietary pattern for these Eurasian pioneer early modern human populations not observed yet for Neanderthals of the region’, says Domingo García. ‘Probably the ability to have this dietary plasticity helped them to adapt to extreme northern environments, helping them in their Eurasian "enterprise" compared with Neanderthals, which eventually disappeared’, he adds. Stable isotope analyses are used to provide information about regular consumption of different types of dietary protein.

The high quality of this 45 000-yearold genome also enabled the team to estimate the rate at which mutations accumulate in the human genome.

They found that between one and two mutations per year have accumulated in the genomes of populations in Europe and Asia since the Ust’-Ishim man lived.

This is similar to recent estimates from counting genetic differences between parents and children, but lower than more traditional, indirect estimates based on fossil divergences between species.

Fu Q. et. al. The genome sequence of a 45,000-year-old modern human from western Siberia, Nature, 23 October 2014, DOI: 10.1038/nature13810 Issued by Katherine Wilson, Communication, Development and Marketing Manager, University of Cape Town.

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Vets and researchers with an injured rhino. Image: UP

University of Pretoria focus on research to aid in the rhino’s fight for survival Three rhinos a day are lost to poaching in South Africa. This shocking fact means that if this rate of death continues, there will be no more wild rhinos by 2020. Dr Gerhard Steenkamp of the Veterinary Science Faculty at the University of Pretoria (UP) says the world should realise that this is no longer a simple poaching problem. Rhino horn is the most expensive commodity today. ‘This is organised crime and a war we are losing,’ he says. But UP is dedicated to learning more about this poorly understood species in an attempt to save them from this tragic fate.

Research at UP’s veterinary faculty has provided significant advances in research that can help to save this species from extinction. The UP Veterinary Genetics Laboratory (VGL) has established a method of obtaining a DNA profile from rhino horns, which provides evidence that is used in criminal cases against those found in possession of rhino horn or other evidence relating to rhino poaching. This has helped to secure harsh prison sentences for poachers and rhino horn smugglers, with sentences of up to 29 years imposed.

Director of the VGL, Dr Cindy Harper, developed a unique DNA profiling database of individual rhinos, the Rhino DNA Index System or RhODIS®. The name comes from the FBI’s human DNA database, CODIS. RhODIS® is a collection of DNA profiles and samples from live and poached rhinos, as well as stockpiled horns. This is used to help trace recovered rhino horn and can also trace items of other evidence back to a specific poached animal. Less than 0.1 mg of horn

is enough to provide the necessary DNA samples.

This technique has lead to amended legislation by the South African Department of Environmental Affairs (DEA). It is now mandatory for RhODIS® samples to be collected from all poached rhinos and other rhinos that are immobilised or die. All kits are submitted to the VGL for inclusion in the RhODIS® database. The VGL also offers training on RhODIS® procedures to the international community, the South African Police Service (SAPS) investigators, prosecutors, government’s Green Scorpions, veterinarians and wildlife officials.

This UP brainchild has been recognised by the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) for its role in assisting with tracking wildlife products and prosecuting international wildlife criminals.

The database also contains DNA profiles and samples of rhinos from other African countries, including Namibia, Malawi and Kenya. During a recent trip to India, Harper initiated moves to include that country’s greater one-horned rhinos on the database. ‘There is value in having all rhinos across the world on one database because horns from all over ultimately end up in the same consumer countries,’ Harper said.

Moving from the lab to the field, UP vets Gerhard Steenkamp and Johan Marais have also spent much time investigating rhino anatomy, as well as the species’ response to medication and what instruments to use when treating live

rhinos that survive poaching attacks.

Steenkamp specialises in maxillofacial surgery and Marais in equine surgery.

Marais explains: ‘Out of all mammals, the rhino and horse are probably the most similar’. Steenkamp’s background is particularly useful for rhinos who survive having their horn removed. Steenkamp and Marais have set up a project called Saving the Survivors to facilitate rehabilitation of those rhinos who survive poaching attacks.

After treating several rhinos for facial trauma, Steenkamp and Marais now have a protocol that works, cleaning the wound and applying wound material. A fibreglass-based dressing is then screwed in place over the wound so that the rhino is not able to rub the cover off against the nearest tree. While rhino tissue heals very well, large gaping wounds do take a long time to heal. Because it is impossible to treat a wounded rhino daily, they had to find material that would only need to be changed every six weeks.

However, despite all these efforts, rhino poaching continues to escalate. With 769 rhinos already poached this year, and 3 231 killed since 2010, time is rapidly running out. Harper says radical solutions will have to be found to save this species from extinction. In a war fuelled by greed for an expensive status symbol, one of the biggest challenges South Africa’s rhino face today is the lack of money and time, say Steenkamp and Marais.

To find out more, contact the author, Louise de Bruin: loudebruin@gmail.com or +27721235384 Issued by the University of Pretoria.

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Life stage influences the appearance of individuals within a species. In this photograph you can see that there are lots of different forms of the larvae of moths and butterflies in grassland – you will know these as caterpillars. Image: Lize Joubert

When seeing is not believing Lize Joubert explains the intricacies of invertebrate polymorphism.

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In this photograph you can see the nymph of P. leprosus (A) and the adult (B) – the nymph has distinctive characteristics that allow it to be identified and there are clear differences between the nymph and the adult. Image: Lize Joubert

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re they different or are they the same? They appear different, but are they different? Do they belong to separate species? Those were the kind of questions that raced through my brain when I first embarked upon a study of the diversity of invertebrates in the KwaZulu-Natal Midlands of South Africa. As if it was not enough that this was a region renowned for its high levels of faunal and floral diversity, I was now also bombarded with the high levels of within-species variation. Of course, this was much to my delight!

Polymorphism is the differences in appearance (e.g. shape, size, colour and behaviour) found among

individuals of the same population at the local spatial scale, or among individuals of the same species at the regional spatial scale. These differences might be due to life stage (larvae vs. butterfly, or tadpole vs. frog); sex (male vs. female); environmental conditions (summer vs. winter, wet vs. dry) or even interactions with other species (e.g. predation or competition).

Immature vs. adult Grasshoppers and locusts belong to the order Orthopera. In most cases, it is not possible to identify immature grasshopper individuals (i.e. nymphs) to species level because certain characteristics specific to the species only develop when the individual

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The bright organge summer morph of the Gaudy Commodore looks completely different from the blud winter morphs. These two morphs could be mistaken for two different species.

Image: Christeen Grant

reaches maturity. Therefore, our ability to identify grasshopper and locust nymphs is limited to only a few common species. One species that can be identified as a nymph is a Milkweed locust (Phymateus leprosus), commonly found in the KwaZuluNatal Midlands. In the photograph (previous page) you can see the differences in appearance between a P. leprosus nymph and adult.

Moths and butterflies belong to the order Lepidoptera, and go through a larval stage before reaching adulthood.

It is quite common to come across these larvae feeding on various plant species in natural grassland.

The larvae of different species look different: they can be thin and slender;

There is a clear difference in size between male and female Green Milkweed locusts. But male and female African Monarch butterflies are the same size.Image: Lize Joubert

thick and scrumptious; brightly coloured or dull; and smooth or woolly. Although our knowledge of moths and butterflies is constantly improving, it is in most cases still not possible to identify moth and butterfly species based on the appearance of their larvae.

Adult moths and butterflies can move around – their larvae can only move for very short distances.

Biologists would find it very useful to be able to identify larvae to species level because the presence or absence of the larval stages of a species in an area would give a good indication of whether that area is truly part of the ‘habitat’ of a particular species, or if the moth or butterfly only move into

an area for a specific part of their lifecycle. In a world in which species’ habitats are increasingly broken up, it is important to know what type of habitat is needed for the long-term survival of a species in a landscape.

Male vs. female The differences between males and females of the same species is probably the most well-known form of polymorphism, and is called sexual dimorphism. Examples include differences in colour and tail length for the Cape Sugarbird (Promerops cafer) in fynbos or the Red-Collared Widowbird (Euplectus ardens) in grassland. Among many ungulates, presence of horns is often 10| 4 2014

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Green and blue morphs of the Rooibaadjie (Dictyophorus spumans) co-occur in the same region and season.

We do not know whether genetic differences or environmental conditions drive variations in colour. Image: Lize Joubert

the distinguishing feature of adult males. In the extreme case of Nyala (Tragelaphus angasii), males and females look completely different.

Differences in size among sexes is also quite common, and is linked to ease of mounting or copulation during reproduction. Unlike most mammal species, invertebrate males are smaller than females. The size difference between male and female Green Milkweed Locusts (Phymateus viridipes) is representative of size differences among other grasshopper species. Nevertheless, not all invertebrates exhibit this kind of sexual dimorphism. You can see this in the African Monarch butterfly (Danaus chrysippus) where males and females are the same size.

Genetic variation vs. phenotypic plasticity Differences in the morphological and behavioural characteristics of a species might be caused by genetic differences and/or phenotypic plasticity. It makes sense that different sets of genetic material will give rise to differences in appearance (i.e. phenotype) and, possibly, different species. However, it is slightly more challenging to grasp the possibility of phenotypic plasticity, i.e. when differences in phenotype arise from different environmental conditions despite similarities in genetic material.

In 1984, Shapiro wrote that ‘many butterflies have seasonal phenotypes which are often so different as to have been described as different species’. He also mentioned that some beautiful examples of seasonal dimorphism can be seen in the Precis genus, which is represented in South Africa by three species, including the Gaudy Commodore (P. octavia). This species is found throughout the year, but switches between summer and winter morphs that differ in appearance and behaviour. The summer morph (August to March) is red to brightorange and prefers koppies and hilltops, while the blue winter morph is typically seen in shady patches along embankments or road cuttings.

It is not clear to which environmental cues this species responds, but it is probably a combination of 40

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precipitation, temperature and day length during the early stages of development (pupae and larvae).

The Rooibaadjie (Dictyophorus spumans) is a large, charismatic grasshopper species found in various bold colours throughout South Africa. In the KwaZulu-Natal Midlands, the blue and green colour morphs co-occur in the same region.

The public notices this species, as is evident by the large number of photos posted on iSpot, which is a website run by the South African National Biodiversity Institute (SANBI) aimed at addressing citizen science throughout the country. In a conversation between ecologists Tony Rebelo and Riaan Stals on iSpot, it is concluded that the century-old classification of D. spumans into five subspecies by Bolívar should be ignored until this species can be revised (Orthopteran Species File Version 5.0). Until then, we can simply admire the astonishing array of colours and guess whether they are different … or whether they are the same. q Lize Joubert recently finished her PhD in Conservation Ecology, which dealt with the effect of different management regimes on the diversity of grassland conservation corridors among forestry plantations. She is passionate about people and the environment, which is why she always tries to reconcile biodiversity conservation with commercial ventures, such as agriculture, urban development or forestry. Her hobbies include mountain biking, scuba diving, and hiking.

Recommended reading: Orthopteran Species File. Version 5.0. http:// orthoptera.speciesfile.org/Common/basic/Taxa. aspx?TaxonNameID=1120657 Pfennig, DW, Wund, MA, Snell-Rood, EC, Cruickshank, T, Schlichting, CD and Moczek, AP. Phenotypic plasticity’s impacts on diversification and speciation. Trends in Ecology and Evolution. 2010. 25:459-467 Picker, M, Griffiths, C and Weaving, A. Field guide to insects of South Africa. 2004. Struik Nature. Cape Town.

Robinson, BW and Wilson, DS. Genetic variation and phenotypic plasticity in a trophically polymorphic population of pumpkinseed sunfish (Lepomis gibbosus). Evolutionary Ecology. 1996.10:631-652 Shapiro, AM. The genetics of seasonal polyphenism and the evolution of ‘general purpose genotypes’ in butterflies. In: Wohrmann, K. and Loeshcke, V. (eds) Population Biology and Evolution. 1984. Springer-Verlag, Berlin. Pp. 16-30

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New insight into human origins Once again, southern African archaeology is significant in defining early human origins. Quest with the University of Cape Town.

A fragment of the jaw showing the teeth.

Image: Alan Morris

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team of international researchers, including University of Cape Town (UCT) Emeritus Professor Andrew Smith and Professor Alan Morris, has unearthed remains of a skeleton from which they have extracted mitochondrial DNA (mtDNA) that can provide clues to early modern human prehistory in southern Africa.

The 2 330-year-old male skeleton was excavated in 2010 by Professor Smith at St Helena Bay, South Africa. The skeleton was unearthed by pipeline workers digging a trench. The researchers generated a complete ancient mitochondrial genome from the skeleton which, according to Professor Smith, ‘is the first genomic evidence that pre-pastoral southern African marine foragers carried the earliest diverged maternal modern human lineages’. The man was buried in a grave dug in a shell midden, formed from discarded shells that have built up over thousands of years.

The DNA was extracted from the inner canal region of a single tooth and ribs.

Until now, genetic data have never been recovered from the indigenous peoples that once sustained life along the southern coastal waters of Africa pre-pastoral arrival.

This was possible thanks to input from world-renowned expert in African genomics, Professor Vanessa Hayes. Based at the Garvan Institute of Medical Research in Sydney, Australia, Professor Hayes heads the Laboratory for Human Comparative and Prostate Cancer Genomics. The genome extracted from this individual’s DNA is unique – there are no known descendants

The location of the excavation site, showing how close it is to the sea. Image: Google Earth

The skeleton in the excavation site. Image: Andrew Smith

of this man alive today, which means that either his line has died out or we have not yet come across any of his descendants, according to Professor Morris.

Professor Morris, a biological anthropologist, confirms that the man was a ‘marine forager’ who was in his fifties when he died. Professor Morris said: ‘A bony growth in his ear canal, known as “surfer’s ear”, suggests that he spent some time diving for food in the cold coastal waters, while shells carbon dated to the same period and found near his grave, confirmed his seafood diet’.

The closest surviving lineage to this skeleton is represented by click-speaking forager peoples largely found in semidesert regions of Namibia and Botswana.

Archaeological, historical and genetic evidence indicates that there once was a broader southerly dispersal of click speaking peoples, including southward migrating pastoralists and indigenous marine-foragers.

‘This study highlights the significance of southern African archaeological remains in defining early modern human origins,’ Professor Smith added.

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News

New solar car ready to defend title It may not have been the most elegant vehicle on the road but the ‘Batmobile’, as it was affectionately known, certainly was effective. It powered a group of Potchefstroom Campus Engineering students to joint first place and four records in their first attempt at the Sasol Solar Challenge, an international event in which university students design and drive solar-powered cars.

Not a drop of petrol was used along the way. Contestants are allowed to charge their car’s batteries with DC power before the race starts but once on the road, the sun is strictly the only source of energy.

Now the Batmobile has gone into retirement, making way for a completely new car for the 2014 Sasol Solar Challenge. Meet the Sirius X25.

‘The competition rules change to take technology advances into account so you need to build a new car every time. The Sirius X25 is being built entirely by students, has a total weight of only 140 kg and will be able to reach speeds in excess of 100 km/h,’ says Prof. Albert Helberg, team leader.

Like the first car, the new one will be a one-seater vehicle with the ‘bare basics’ inside, consisting of a steering wheel, brake pedal, gas pedal and various compulsory light switches.

‘There are no luxuries like a radio or air conditioner,’ says electrical engineering master’s student Raynard du Preez, who is in charge of the electrical design and battery management system, explaining that these would just weigh down the car. ‘The challenge is to build a car 42

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with the most power within the weight limit – and within budget.’

Mechanically, the new car will be similar to its predecessor, the Batmobile, but will be lighter and more aerodynamic. The entire electrical system has been redesigned, including the solar panels, battery system and the electric motor, Du Preez says. ‘We’ve done a lot of research to find the right battery chemistry and have decided on lithium polymer, one of the newer and best battery chemistries.’

He is one of four postgraduate students who drove the car in the 2014 Sasol Solar Challenge, that took place from 27 September until 4 October. The race was from Pretoria to Port Elizabeth via Bloemfontein, ending in Cape Town. The North West Uuniversity (NWU) team aimed to travel a total distance of 5 000 km by driving extra ‘loops’ – these are optional routes of between 58 km and 132 km at small towns along the way. The greater the distance a car goes in the Challenge, the more points its team can score.

In any event, the NWU team wanted to spend as much time behind the wheel as they could. The reason? ‘It’s quite fun to drive a solar car,’ says Du Preez, ‘but it’s a great feeling knowing that you are driving a car that could potentially change the future of the automobile industry.’

View the video about this year’s solar car: https://www.youtube.com/watch?feature=player_ embedded&v=jRpiyPpMi48 Issued by Nelson Mandela Metropolitan University.

DST-NRF Centre of Excellence in Strong Materials The DST‐NRF Centre of Excellence in Strong Materials (CoE‐SM) is hosted by the University of the Witwatersrand, in partnership with the Nelson Metropolitan University, the Universities of Johannesburg, Stellenbosch, KwaZulu‐Natal and Limpopo, with Mintek and NECSA, and has links with the University of Cape Town, Tshwane University of Technology, Element Six and iThemba LABS (Gauteng).

The CoE‐SM has six Focus Areas: Carbides and Cermets; Carbon Nanotubes and Strong Composites; Ceramic Materials; Diamond, Thin Hard Films and Related Materials; New Ultrahard Materials; and Strong Metallic Alloys.

Prof. Lesley Cornish is the Director of the DST‐NRF Centre of Excellence in Strong Materials and Assistant Dean ‐ Faculty Research for the Faculty of Engineering and the Built Environment. She was also instrumental in the establishment of the African Materials Science and Engineering Network (AMSEN) in 2008 and is the current Director. Prof. Cornish won the National Science and Technology Forum “Eskom Research Capacity Award”, 2013 and was inducted as a Fellow of the Royal Society of South Africa during 2010.

Aim The main aim of the CoE‐SM is to train post graduate students for industry, Science Councils and higher education. Currently, CoE‐SM graduates are working at Element Six, Pilot Tools, Sasol, AcelorMittal, Anglo, Eskom, SAB Miller and other industries, as well as at the Science Councils: Mintek, NECSA, CSIR, SA Welding Institute and NMISA. The CoE‐SM is many graduating South African students.

Major achievements 2004 ‐ 2014 The post graduate students in the CoE‐SM are from the fields of Science and Engineering, and from the disciplines of Chemical Engineering, Chemistry, Mechanical Engineering, Aeronautical Engineering, Metallurgy, and Materials and Physics, and undertake research at honours, masters and doctoral level. The CoE‐SM currently have approximately 5 Honours, 45 Masters and 50 Doctoral students. Over 130 students have graduated at MSc level and above, most of who find employment in industry (over 58), science councils (over 25) and higher education (over 45).

Amongst the CoE‐SM’s many other achievements are: • Instrumental in starting the SA Nano Technology newsletter, which continued from 2008 until 2011, when it was taken over by SAASTA in 2012.

• The CoE‐SM played a primary role in the establishments of IBSA (India, Brazil and South Africa) Network for research, with ongoing collaborative research. Through the strong connection to IBSA, the CoE‐SM was instrumental in the formation of SASEA (SA Solar Energy Association), launched in November 2013.

Equipment

Leverage of funds allowed for the purchase of many medium to large items of new equipment. Since 2006 the following items have been purchased: Focussed Ion Beam SEM, 2 Veeco Atomic Force Microscopes, NETZSCH Simultaneous Thermal Analysis Facility, F.E.I. Transmission Electron Microscope, DTA and automatic sampler, Spark Plasma Sintering furnace, Raman spectrometer, X‐ray spectrometer, Zetasizer Nano ZS, Zeiss SEM, Electron Probe Micro‐ analyser and a Gleeble 3500 thermal mechanical simulator.

Research The CoE‐SM is engaged in many different aspects of research in materials, lately undertaking energy‐related work, and also developing materials that have strategic interest to South Africa.

The materials include titanium, platinum, ruthenium and vanadium. The CoE‐SM has produced at least 8 patents which are still registered, including 5 from Ceramics, and in collaboration with NMMU and Element Six are in the process of developing more. The CoE‐SM is on its third project on steels for railway applications, which is indicative of its alignment with the national needs. It is also developing a diamond sensor for undertaking radiographic measurements for mammography.

The collaboration with Pilot Tools has been ongoing since the CoE began. Pilot is a 100% South African owned company, and so the CoE‐SM has been assisting a local company improve their production processes and products. All the research projects completed in the CoE‐SM with them have come directly from their manufacturing process which either contributed towards improvement of the production processes and the materials – even development of new materials, and the CoE‐SM has helped them compete better in a global market.

To date, the CoE‐SM has published over 520 peer‐reviewed journal papers, and over 270 conference publications.

Knowledge Brokerage & Outreach

The CoE‐SM was a major force in establishing the African Materials Science and Engineering Network (AMSEN), a RISE (Regional Initiative of Science Education) Network, funded by the Carnegie Corporation of New York from 2009‐2016. AMSEN supports African students using external funding. AMSEN has 20 postgraduate students, including six at the University of the Witwatersrand, and the remainder at the partner Institutions i.e. the Universities of Botswana, Nairobi, Namibia, and the Federal University of Akure (FUTA) in Nigeria. Since 2009, seven PhDs have graduated (2 more have passed, but not yet graduated) and seven Masters Level have graduated, and at least 44 refereed journal papers have been published. The University of Ghana is in the process of joining AMSEN. The CoE‐ SM also runs AMSEN’s Secretariat.

As part of the Outreach programme, members of the CoE‐SM helped establish the Materials Course across the Faculties of Science and Engineering and the Built Environment at Wits.

The CoE‐SM organises an annual competition for Grade 10 learners, the Materials Science Schools Poster Competition, which encourages and promotes and interest in Materials aligned with the National School Curriculum.

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Books

Often unwelcome and sometimes deadly Snakes and Snakebite in Southern Africa.

By Johan Marais.

(Cape Town. Struik Nature. 2014) This fully revised edition of this book is also billed as essential first aid for snakebite, and that is usually people’s first reaction to snakes – will it bite and what do I do if it does?

However, to know the answers to these questions you have to know what kind of snake you have just encountered – and this book is first and foremost a field guide to the snakes found in southern Africa.

In the introduction the author points out that although most people are terrified of snakes, they are secretive creatures that will avoid humans whenever they can.

In fact, although in southern Africa many people spend considerable amounts of time outdoors, encounters with snakes are uncommon and snakebite is rare. Apparently the puff adder will not always bite when trodden on – preferring to remain in its camouflaged position. Black mambas and cobras are reputed to be aggressive and to chase people, but this is a fallacy and even black mambas will flee people if they can. It is when cornered or handled that snakes will strike in self-defence – often with serious consequences.

With all that in mind, the reader is led into the fascinating world of snakes as predators – they cannot hear most airborne sound for example, but are sensitive to vibrations. Their flickering tongue is used for ‘smell’ and for finding mates in season.

There is an excellent, detailed section on snakes in gardens – generally harmless, but the seriously venomous do occur. There are tips on making your garden less attractive to snakes and a list of ‘Popular myths busted!’. The section on snakebite itself has a large box on how to avoid snakebite – prevention is the best option. There is a good explanation of the symptoms of snakebite and the different types of venom and a comprehensive approach to first aid and medical management of snakebite, including what not to do.

The rest of the book is devoted to identification. There is a distribution map, a diagram showing the average size of the snake in relation to a person, diagrams showing whether the species is diurnal or nocturnal and its preferred habitat. The book is illustrated with excellent colour photographs and the danger level of the snakebite is clearly indicated with each species account.

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Saving our wildlife The Poacher’s Moon: a true story of life, death, love and survival in Africa. By Richard Peirce. (Cape Town. Struik Nature. 2014) Part of the proceeds of this book go to the South African Veterinary Association (SAVA) rhino rescue and this book is about rhinos and how they are being driven to the edge of extinction by greed. In 2011 three private game reserves in the Western Cape were targeted by rhino poachers. This book is the story of how the poachers prepared the scene, launched their attack and escaped into the night and the traumatic aftermath for the rhinos and their carers. The book particularly follows the fate of Higgins and Lady, two rhinos who managed to survive thanks to the care and ongoing support from SAVA. All trade is based on supply and demand and the foreword, by Jacqui Peirce, points out that the conservation of our wild fauna and flora rests on a highly complex set of issues. But it is true to say that the demand for many animal species comes from one country – China and it is here that the conservation NGOs need to concentrate their efforts. In 2013, 1 004 rhinos were poached in South Africa. At the time of writing, Save the Rhino poaching statistics showed that, up to 22 September 2014, 787 rhinos had been poached. Unless the demand for rhino horn is stopped, the species will become extinct – and the demand is now for an expensive commodity for its own sake, not only for the supposed medicinal properties of the horn.

Rhino horn has become a status symbol because of its cost – this is the root of the current trade.

Rhinos have been on Earth for about 50 million years. Humankind has been here for the blink of an eye in comparison. This book is an important read – as a tribute to a particular set of incidents and two rhinos – and because it highlights just how close we are to losing a species forever.

On hard work and its rewards Jojo’s Wire Car. By Veronica Lamond. (Cape Town. Struik Nature. 2014) This charming children’s book looks like a simple story about a little boy who won a competition. But it can be read on another level as well. Jojo is a young boy who is representing young children all over Africa. He has hardly any time to play. He has to walk many kilometres

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to school every day. He has to help his granny with her sore foot with housework, fetching and carrying water and many other household chores. He has to sell fruit by the side of the road to make money to buy books for doing his school work. And all the while Jojo watches children from more fortunate (but still poor) families at play while he works hard.

Then his fortunes change. There is a competition for children under 10 with the best-made wire car and the prizes are wonderful – two years of free shooling, a bicycle and full sports kit. Granny didn’t think that Jojo would have time to make the car, but he works hard to finish his chores quickly and finds innovative ways to gather together what he needs to make his wire car. And of course he wins a prize – not the first prize, but the bicycle, which means that he gets to and from school faster, helps him to get jobs to pay for his school books and leaves him enough time to play. Hard work and its reward!

Learning tracks My first book of Southern African Animal Tracks. By Chris and Mathilde Stuart. (Cape Town. Struik Nature. 2014) This book in the ‘My first book of ...’ series introduces 55 different types of animals and the footprints they leave behind. The animals and birds included are those you are likely to find in nature reserves or game parks and your garden. The book is fun to read at home and an invaluable guide on trips.

The introduction tells you where to look for tracks – around water and in firm, dry sand. There are tips for tracking – don’t walk over tracks because you smudge them, look around you as you walk, move quietly and keep a safe distance from wild animals. There are size

comparisons for the different animals you are likely to encounter and the difference between a back track and a front track. Some of the tracks are life-sized, while others have a scale next to them to show you how large they are in comparison to your hand or foot. As with all the books in this series, the text is in English, Afrikaans, Xhosa and Zulu.

Colourful African mammals African Mammals to read, colour and keep. By Sally MacLarty. (Cape Town. Struik Nature.

2014) This book is ideal for younger children and will introduce them nicely to the wonderful world of African mammals, from those that they may see in the garden to those in game parks.

Each species has a page to itself, with large line drawings, clearly showing the different features of the animals so that different colours can be used. There is a colour section in the middle of the book, which can be pulled out to guide the child as to which colour to use.

Children will enjoy hours of colouring fun, with more than 40 animals to colour in. Each illustration provides interesting facts as the child works through the book.

Discovering Cape Town My Cape Town: ABC. Compiled and illustrated

by Sandy Lightley. (Cape Town. Struik Travel and Heritage. 2014) The aim of the book is to teach children their ABC and at the same time provide an illustrated guide to Cape Town. The lively illustrations bring the city to life and at the same time teach awareness of sounds and letters. There are fun questions on each page and a parent’s guide at the back, with addresses and website, key activities and places of interest such as the aquarium, Boulder’s beach, Cape Point and Hout Bay harbour.

This beautifully illustrated book should provide hours of fun for the whole family.

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❚❚❚❙❙❙❘❘❘ University of Pretoria news Bottlenose dolphins off the coast of Namibia.Image: S Elwen

A study reveals that Africa’s wild bottlenose dolphins use unique whistles to address each other. From the University of Pretoria.

Whistling a different tune H

umans greet each other by name.

Bottlenose dolphins do much the same but they use a ‘signature whistle’.

Scientists know that a signature whistle type is a learned, individually distinctive whistle type that a dolphin broadcasts to identify itself. The fact that dolphins can learn and use something like a signature whistle suggests that dolphins have a complex communication system.

Dolphins are social animals and keeping in contact using calls is important, particularly in environments where animals are dispersed across a wide area and cannot see each other easily. Dolphin signature whistles are unique among non-human animals. Up until now, most research into dolphin signature whistles has come from captive studies, so this recent South African study is particularly important.

‘And for the first time we can now confirm that African bottlenose dolphins in the wild also use this acoustic communication system when they meet at sea,’ explains Dr Tess Gridley, a post-doctoral fellow at the University of Pretoria’s Mammal Research Institute (MRI) and the lead scientist of a study on the signature whistles of wild bottlenose dolphins (Tursiops truncatus) from Namibia.

The study, co-authored by Dr Simon Elwen, also from the MRI, Hannah Kriesel and Aurora Nastasi, was published in September 2014 in PLOS ONE, an open access journal.

Sound communication Most dolphin species rely on a rich repertoire of sounds in their day-to-day lives. They use sound to find food and navigate (echolocation) as well as communicate with each other.

Dolphins can learn new sounds and can quickly mimic novel sounds that they hear.

Although fairly common among many bird species and humans, this ability, called vocal production learning, makes them quite special among mammals.

The vast majority of global research on bottlenose dolphin acoustic communication has been conducted in captivity. These studies have shown that each animal learns its own individually distinctive whistle, called a ‘signature whistle’, in the first year of life and

that they use the same whistle throughout life.

Recent research in Scotland has shown that signature whistles are exchanged by groups of dolphins when they meet at sea and that signature whistles are used to address each other – a bit like a name in humans.

However, research on dolphin acoustic communication in the wild is less common and until now it was unclear whether African bottlenose dolphins use a similar communication system to those studied in other localities.

Drs Gridley and Elwen conduct research on whales and dolphins in Namibia and run the Namibian Dolphin Project. Since 2009 they have been investigating the fascinating lives of a small population of bottlenose dolphins inhabiting Walvis Bay, located on the central Namibian coast.

‘The research ... outlines some of the first results of this study. It demonstrates that individual dolphins are likely to be using unique signature whistles throughout their lives, probably to keep in contact and address each other.

‘This is the first time that signature whistles have been identified from any population of this species inhabiting African waters, and it is only the second wild population of this species where the features of the signature whistles have been described in detail,’ says Dr Gridley.

The research was the Master’s thesis of their student Ms Hannah Kriesel, who graduated earlier this year from the University of Göttingen in Germany.

More than 79 hours of recordings, collected over four years in the presence of dolphins, were used to generate a catalogue of 28 signature whistles – around one quarter of the population in Namibia. Evidence for twovoice whistle production (imagine if you could whistle two different tunes at the same time) was also found. According to Dr Gridley, twovoice sound generation occurs in some bird species and may be a way to make calls more complex – which can be a good thing if you want a really unique signature call.

The study also shows that the number of

Bottlenose dolphins leaping. Images: Tess Gridley

different signature whistles recorded increased when group sizes were larger and when calves were present – something you might expect if signature whistles are used to address each other and help maintain contact between animals, particularly between mothers and calves.

The outcomes of this research provide an important stepping stone for future studies into how sounds are used and whether human activities are affecting the communication of our whale and dolphin populations. This is particularly important in Walvis Bay, where the impacts of human activity threaten the small bottlenose dolphin community. Researchers from the MRI Namibian Dolphin Project hope to monitor changes in dolphin behaviour related to such potential stressors.

Visit the website: www.namibiandolphinproject.com

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Back page science

MIT cheetah robot to run and jump, untethered, across grass The cheetah is the fastest land animal on Earth, able to accelerate to 96 km/h in just a few seconds. As it ramps up to top speed, it pumps its legs in tandem, bounding until it reaches a full gallop.

Now MIT researchers have developed an algorithm for bounding that they’ve successfully implemented in a robotic cheetah – a sleek, four-legged assemblage of gears, batteries, and electric motors that weighs about as much as its feline counterpart. The team recently took the robot for a test run, where it bounded across the grass at a steady clip. The robot sprinted up to 16 km/h, even continuing to run after clearing a hurdle.

The MIT researchers estimate that the current version of the robot may eventually reach speeds of up to 50 km/h. However, it still has a way to go before it reaches 96 km/h.

Source: MIT

Bonn, says ‘Our experiments in the laboratory revealed that the typical IT building is not adequately protected against Internet-based attacks. Their network components could be hijacked for use in botnets’. The hackers do not have to seek out the PCs as in the past; instead, they look for the components in building automation that link the buildings with the Internet. These are small boxes installed in the buildings that look and work like routers for home computers.

‘However, they are configured quite simply, can only be upgraded with some difficulty, and are loaded with security gaps. The communications protocol that they use is obsolete,’ explains Wendzel.

At FKIE, the team has developed security software that can easily switch between Internet and building IT. The technology filters out potential attacks from communications protocols even before they reach the four walls of the actual brick-andmortar home or office building. No matter what technologies are being used within the building, with this approach, they do not have to be replaced.

If the alarm goes off, then the incident is immediately dispatched to the ‘normaliser’. This either blocks the incident in its entirety or modifies it accordingly.

Source: Fraunhofer-Gesellschaft

Scientists report first ‘semi-aquatic’ dino, larger than T. rex Courtesy of the National Geographic Society and World Science staff

A dinosaur discovered over a century ago turns out to have probably been ‘semi-aquatic’ – the only known dinosaur adapted for living and hunting in a water environment, scientists say.

According to the report, new fossils of the huge predator reveal that it adapted to life in the water some 95 million years ago, providing the strongest evidence to date of a dinosaur able to live and hunt in an aquatic environment.

The dinosaur, Spinosaurus aegyptiacus, lived toward the end of the age of the dinosaurs in what is today North Africa.

The beast is estimated to have been more than 3 m longer than the largest known Tyrannosaurus rex specimen.

Source: http://www.world-science.net.

A digital skeletal reconstruction of Spinosaurus. The light grey outline indicates where the flesh would have been. The reconstruction is a composite of bones from different fossils. The bones coloured blue are missing bones that are inferred.

Image: Model by T. Keillor, L. Conroy, & E. Fitzgerald; courtesy Ibrahim et al., Science

The MIT cheetah robot. Image: Jose-Luis Olivares/MIT

On the way to a safe and secure smart home A growing number of household operations can be managed via the Internet. Today’s ‘SMART HOME’ promises efficient building management, but often the systems are not secure and can only be retrofitted at great expense. Scientists are working on a software product that defends against hacker attacks before they reach the building.

Dr Steffen Wendzel of the Fraunhofer Institute for Communications, Information Processing and Ergonomics (FKIE) in

Building management with a tablet computer: In several modern office buildings, lights, louvres (blinds) and doors can be centrally controlled via the Internet. That brings gains in efficiency – but it holds risks, as well. Image: Fraunhofer FKIE

Artist’s reconstruction of Spinosaurus.

Image: Courtesy of NGS

MIND-BOGGLING MATHS PUZZLE FOR Quest READERS Q uest Maths Puzzle no. 31

Win a prize!

When certain numbers are placed in the empty squares of the magic square below, the sum of the three numbers in each row, column and diagonal is the same. What number should be in the centre square?

Send us your answer (fax, e-mail or snail-mail) together with your name and contact details by 15:00 on Friday, 6 February 2015.

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6 x 40 = 240 food parcels divide this by 8 and you get 30 days.

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Young Science Communicators’ Competition ARE YOU PASSIONATE ABOUT YOUR SCIENCE? The South African Agency for Science and Technology Advancement invites young scientists to share their passion for their field of study and work through the Young Science Communicators’ Competition.

NEWSPAPER/ MAGAZINE ARTICLE

This year’s competition includes four categories: NEW MEDIA: VIRAL COMMUNICATION PIECE The viral nature of popular and entertaining videos that are spread by social media and e-mail makes them a highly effective method of reaching a lot of people in a short period of time.

OPEN CATEGORY Other effective forms of communication include drama, song, poetry, cartoons and more.

As a traditional mode of communication, print media can reach a wide readership and interest the public in science and science-related issues.

RADIO SCRIPT Radio has far-reaching potential into areas where other forms of communication may be limited, such as in rural communities.

Successful radio communication conjures up the “theatre of the mind”.

Go to www.saasta.ac.za and follow the links through the Young Science Communicator’s Competition to view the winning entries and finalists in the previous competitions.

STAND A CHANCE TO WIN: •

A trip to an international science communication conference or workshop for the overall winner.

•

Cash prizes for the winner and runner-up of each category. Cash prize for the best communication piece in line with the theme of the International Year of Crystallography.

•

A People’s Choice Award will be awarded based on public voting through social media for the top entries selected by the judges.

GET INSPIRED - GET IDEAS! AND INSPIRE OTHERS CLOSING DATE: 5 JANUARY 2015 Find out more on how to enter and the rules and regulations of the competition at www.saasta.ac.za Follow us on Facebook