| Future Professor Zininga is set on finding a cure for malaria | http://www.sun.ac.za/english/Lists/news/DispForm.aspx?ID=9941 | | Future Professor Zininga is set on finding a cure for malaria | Corporate Communications and Marketing | <p>Beyond the academic challenge, two things made Dr Tawanda Zininga decide to become a biochemistry lecturer at Stellenbosch University (SU). When he first visited the SU campus in 2019, a shuttle picked him up from the airport and he was struck by the scenic drive. “I thought, wow! The landscape is just mind-blowing. The second thing that convinced me was the friendliness of the people. The hospitality of my colleagues made a deep impression."<br></p><p>Originally from Zimbabwe, Zininga is now settled in Stellenbosch with his wife Chipo and their two children. Since he started working at SU's Faculty of Science in 2020, his career has gone from strength to strength. Apart from numerous travel awards, he was recently awarded the Rehana Malgas-Enus Award from SU's Early Career Academic Development Programme.</p><p>Last year he was selected to be part of the prestigious Future Professors Programme (FPP), a flagship initiative of the Department of Higher Education and Training. The FPP is administered under the helm of Prof Jonathan Jansen, distinguished professor of Education at SU, and aims to enhance the academic excellence and leadership qualities of a carefully selected group of lecturing staff at the country's 26 universities. </p><p>All FPP fellows show promise of becoming leaders in their field and taking their place as part of a transformed next generation of South African professors across all disciplines.</p><p>The youngest of ten children, Zininga's interest in science is rooted in a childhood experience that still informs his work. “I started developing an interest in science after suffering from malaria twice during my childhood. This made me interested in contributing to minimizing the human suffering from malaria."</p><p>Zininga is the first in his family to get a degree and he jokes that at family gatherings his siblings keep him very busy asking for medical advice. He initially studied Medical Laboratory Sciences at the College of Health Sciences at the University of Zimbabwe in 2005 and completed a MSc in Molecular Biology at Staffordshire University, in the United Kingdom in 2012. “I worked for about six years as a medical scientist in Zimbabwe and later Botswana, where my work was focused on diagnosing patients using clinical samples for molecular, biochemical, immunological, histological and haematological diagnostics. These stints helped me to appreciate the importance of proteins in general and more specifically in human systems," Zininga explains.</p><p>He completed his PhD in Biochemistry in 2016 at the University of Venda and received an Africa-Germany Network of Excellence in Science (AGNES) junior researcher award in the same year. He has established collaborations with the University of KwaZulu-Natal and the University of Cape Town and internationally with the Bernhard Nocht Institute for Tropical Medicine and the Ludwig Maximilians-University Munich, both in Germany. Zininga holds a Y1 rating from the National Research Foundation (NRF).</p><p>“During my undergraduate years, I was always intrigued by how biochemistry holds the key to understanding human-pathogen interactions. I was first introduced to protein biochemistry by my PhD supervisor, Prof Addmore Shonhai at the University of Zululand as a PhD student. As fate would have it, I moved to the University of Venda at the same time my supervisor transferred to head the biochemistry department. As someone who was interested in malaria from my early years, I jumped at the opportunity. I could now see myself contributing to the fight against malaria."</p><p>For the past few years, Zininga's research has been focused on the role of heat shock proteins in malaria transmission. At the heart of his research is the intriguing fact that the malaria parasite can survive in two physiologically distinct hosts – the cold-blooded mosquito and warm-blooded humans. This is due to a set of molecular chaperones called heat shock proteins in the malaria parasite, Zininga explains.</p><p>“If we can understand how the parasite manages to use its heat shock proteins to survive stress, we can use this knowledge to design drugs targeting this system to weaken the parasite and potentially eliminate it. My research is focused on understanding how the protein folding system of the malaria parasite is so efficient to enable the parasite to be resilient to heat, environmental, and drug-induced stress. To this end, we are now focusing on the endoplasmic reticulum, one of the cell organelles of the parasite that has been shown to be responsible for facilitating parasite resilience to drug-induced stress. The correct functioning of the heat shock proteins in this organelle has been implicated in the development of artemisinin resistance." The ultimate aim of Zininga's research is to help reverse drug resistance in malaria parasites. </p><p>One of the advantages of the FPP programme is that it has given him access to other academics working in fields that complement his research. “Being included in the Future Professors Programme is motivating me to reach greater heights considering the exposure that I get from some of the best academics in South Africa. I'm sure this will create several lifelong networks. I've already started benefiting by getting mentorship from earlier cohorts.</p><p>“Some of the scientists who are also part of the programme have given me fresh perspectives on my research. It's very valuable to get insights into the societal dynamics that impact the management of a disease such as malaria."</p><p>Being part of FPP has also provided Zininga with support to apply for research funding and opportunities to travel abroad for his research. He is going on a sabbatical in 2024 and hopes to use the time to deepen his research to ultimately contribute to finding a cure for one of Africa's deadliest diseases. Beyond malaria research, he is also interested in non-communicable diseases such as cancer and cardiovascular diseases. He is collaborating with various medical experts such as UCT's Prof Karen Sliwa, director of the Cape Heart Institute, and Dr Graham Chakafana of Hampton University on peripartum cardiomyopathy. Zininga is also working with SU's Dr Balindiwe Sishi on identifying heat shock protein biomarkers for cardiotoxicity during breast cancer.</p><p>Apart from academic work, Zininga hopes to make time for his two other passions during his sabbatical – hiking and fishing.<br><br></p><p><br></p> |
| Unique collaboration leads to establishment of international research group in polymer separation | http://www.sun.ac.za/english/Lists/news/DispForm.aspx?ID=9944 | | Unique collaboration leads to establishment of international research group in polymer separation | Wiida Fourie-Basson (media: Faculty of Science) | <p>The Leibniz-Institute for Polymer Research (IPF) in Dresden, Germany, and the Department of Chemistry and Polymer Science at Stellenbosch University (SU) have established a joint <a href="https://www.polymerseparation.org/">IPF-SU research group in polymer separation</a>.</p><p>The 20-member group, which now spans across Africa and Europe, is led by <a href="https://www.ipfdd.de/en/organization/organization-chart/personal-homepages/prof-dr-albena-lederer/">Prof. Albena Lederer</a>, head of the Centre for Macromolecular Structure Analysis in the <a href="https://www.ipfdd.de/en/research/institute-of-macromolecular-chemistry/">Institute for Macromolecular Chemistry</a> at IPF Dresden since 2007. She is now also holder of the Sasol Research Chair in Analytical Polymer Science at SU, formerly held by <a href="/english/Lists/news/DispForm.aspx?ID=6306">Prof. Harald Pasch</a> for 12 years.</p><p>Prof. Lederer, who divides her time equally between Stellenbosch and Dresden, says both groups currently benefit from the analytical and technical equipment in the different laboratories, as well as the diverse skill sets of the researchers.</p><p>“Over the years Prof. Pasch established an impressive and unique array of analytical and technical equipment in his lab here at SU. At international conferences he always used to inspire us with exciting results, despite coming from a developing country," she explains from her office at SU's Polymer Science building. </p><p>It was after one such international conference in 2016 that he invited her to visit his lab, especially as he was considering retirement soon. That is how the idea of a joint research group was born.</p><p>“It wasn't easy to get this off the ground, as it was a first for both IPF Dresden and Stellenbosch to combine two groups and two labs under one umbrella," she adds.</p><p>Since the official establishment of the group in 2020, they have secured funding from national and international funding agencies such as the European Union, the European Union's Horizon 2020 programme, the Alexander von Humboldt Foundation, South Africa's National Research Foundation (NRF), SASOL, the German Research Foundation, the Leibniz Association, Stellenbosch University and the Technology Innovation Agency (TIA). Most of these projects involve large multidisciplinary teams and collaborations with researchers from a range of institutions in Europe and South Africa. </p><p><strong>Expanding the boundaries of polymer analysis</strong></p><p>In addition to unique multidimensional separations established by Prof. Pasch, today, the group focuses on the specific adaptation of field flow fractionation (FFF) to effectively and reliably analyse highly complex macromolecular systems. Field flow fractionation is a technique used to separate and analyse different components of a mixture based on their size, shape and other physical properties. The separation and quantification of encapsulated or released drugs realised in this manner are of great importance for the development of new therapeutic methods.</p><p>Prof. Lederer says that by coupling different methods, they have enriched the deep understanding of structural changes within complex macromolecular samples as a function of various parameters.</p><p>“In recent years, we have made great progress in moving from a trial-and-error approach to a targeted theory-based method, including analytical predictions. Over the next few years we plan to develop thermal field flow fractionation into a powerful tool that can be used, for example, to study ultrahigh-molecular-weight polyolefins or the distribution of plasmonic properties in metal-polymer hybrid systems".</p><p>Some of the projects sound like something from science fiction. The <a href="https://www.ipfdd.de/en/research/institute-of-macromolecular-chemistry/center-macromolecular-structure-analysis/polymer-separation/projects/3d4d2/">3D4D<sup>2</sup> project</a>, for example, aims to develop a custom-designed three-dimensional polymer matrix device for dual drug delivery and treatment of acute malaria and malaria transmission. In lay man's terms, this means the development of a custom-designed device that can be injected under the skin, releasing multiple antimalarial drugs in a controllable manner over time, at the same time eliminating malaria distribution by blocking transmission. </p><p>While they are still some way off from the real thing, Prof. Lederer says they have already made significant advances since the start of the project in 2021. “We now have a team consisting of world class international researchers with unique expert knowledge to contribute and enable a significant step ahead in the treatment of malaria".</p><p><strong>Benefits of diversity</strong></p><p>Apart from having access to unique equipment, Prof. Lederer says a major advantage of such an international collaboration is the exposure of young scientists and postgraduate students to other ways of thinking and doing: “I believe one should be open to the world and learn from it. Everyone in my group therefore gets an opportunity to switch labs and learn new techniques and skills in a new environment".</p><p>Only recently, postdoctoral fellow Dr Martin Geisler and PhD student Joshua Johani arrived from IPF Dresden to perform the next part of their work at SU, while Dr Helen Pfukwa will visit IPF Dresden from July to September this year.</p><p>Prof. Lederer's group also recently hosted the <a href="https://ispac-conferences.org/">34th International Symposium on Polymer Analysis and Characterization</a> – the first time in its 35-year history to be held in Africa. It was attended by over one hundred delegates, including a delegation of ten from SASOL. The local organising committee consisted of Prof. Lederer, Dr Helen Pfukwa (SU) and Dr Susanne Boye (IPF Dresden).</p><p>Apart from research on theoretical and applied field flow fractionation for complex nanostructures, the group also focuses on new characterization methods and high-temperature separation of polyolefins, as well as innovative methods for analytics of natural and complex synthetic polymers and for the development of materials from renewable resources.</p><p>According to Prof. Peter Mallon, head of the Department of Chemistry and Polymer Science at SU, a major factor leading to the success of the collaboration is that it is mutually beneficial to both SU and IPF: “This is truly an equal partnership which exploits the complementary equipment and expertise of both institutions in polymer separations. It provides the opportunity for postgraduate students and staff from both institutions to be exposed to a wider array of analytical instruments and expertise than would otherwise be the case," he concludes.</p><p>Prof. Louise Warnich, Dean of SU's Faculty of Science, says the success of the agreement with IPF has thus far exceeded all expectations: “This type of agreement offers a workable solution to obtain scarce expertise that is not available locally. Due to the success of the current arrangement, we are considering similar agreements for other specialist areas".</p><p>Prof. Brigitte Voit, Head of IPF Institute of Macromolecular Chemistry, concurs on the mutual benefit for both institutions: “It is amazing to see how this first-of-its-kind joint appointment has brought us a huge step forward in developing new analytical tools and enhancing science".</p><p><em>On the photo above: Prof. Albena Lederer from the Leibniz-Institute
for Polymer Research (IPF) Dresden in Germany was jointly appointed at SU in
2020. She has now expanded her polymer separation research group at IPF,
founded in 2007, to include the Sasol Research Chair at SU. Also part of the 20-member
group are Dr Susanne Boye (IPF), Dr Martin Geisler (IPF), Dr Zanelle Viktor (SU/IPF),
Dr Helen Pfukwa (SU) and Dr Upenyu Muza (IPF/SU). Photo credit: Leibniz-IPF, Juliana Socher</em><br></p><p><span style="font-size:11pt;line-height:107%;font-family:"segoe ui", sans-serif;color:#242424;background:white;"><br></span></p> |
| Havenga Prize in life sciences awarded to SU microbiologist Prof Gideon Wolfaardt | http://www.sun.ac.za/english/Lists/news/DispForm.aspx?ID=9897 | | Havenga Prize in life sciences awarded to SU microbiologist Prof Gideon Wolfaardt | Faculty of Science (media and communication) | <p>Prof Gideon Wolfaardt from Stellenbosch University (SU) is the recipient of the prestigious Havenga Prize, awarded annually by the SA Akademie vir Wetenskap en Kuns for original research in the natural sciences.<br></p><p>Prof Wolfaardt, a microbiologist by training, is currently director of the <a href="/english/research-innovation/Research-Development/stellenbosch-university-water-institute-(suwi)">Stellenbosch University Water Institute</a> (SUWI) and holder of the Rand Water Chair in Public Health and the ERWAT Chair in Wastewater Management in SU's <a href="/english/faculty/science/microbiology">Department of Microbiology</a>. He also holds a joint appointment as professor in Environmental Microbiology at Ryerson University in Toronto, Canada, and is adjunct professor at the Department of Applied Chemistry and Chemical Engineering, also at Ryerson University.</p><p>Described by colleagues as a down-to-earth scientist with a superhuman work ethic and a passion for his research, he is currently managing six multi-disciplinary research projects looking at, inter alia, contaminants of emerging concern in wastewater effluent; the prevention of groundwater contamination in the context of global and climate change; raising the bio-based industrial feedstock capacity of marginal lands; as well as a Southern African-German collaborative project in the field of water security in Africa. </p><p>His research group was the first from Africa to participate in the Sewage Analysis CORe group Europe (SCORE) project as part of a European network of specialists in the field of wastewater monitoring. Members of this network investigate the use of quantitative measurement of human biomarkers in wastewater to evaluate lifestyle, health and exposure on community level. During the Covid-19 pandemic, his group was also part of a national network of specialists who worked to establish an early-warning system by monitoring wastewater effluence for the presence of SARS-Cov-2.</p><p>While some of their work include fundamental research, his group mainly focuses on water treatment and management, the fate and impact of micro-pollutants, infection control, microbial conversion of biomass, management of mine tailings and nuclear waste, and the environmental fate and behavior of microorganisms.</p><p>Prof Wolfaardt has published more then 100 peer-reviewed articles and book chapters and presented numerous invited seminars in Canada, the United States, Germany, South Africa, Morocco, Austria and Australia. His research on environmental processes in industrial, engineered and clinical settings has a strong emphasis on techno-social innovation, which has led to eight registered patents since 2013. </p><p>According to Prof Alf Botha, head of SU's Department of Microbiology, Prof Wolfaardt is best known amongst postgraduate students, colleagues, industry partners and farmers for his fair treatment of one and all: “Many a time he has helped farmers to solve their water problems, often not expecting anything in return".<br></p><p><br></p> |
| African penguins: climate refugees from a distant past | http://www.sun.ac.za/english/Lists/news/DispForm.aspx?ID=9878 | | African penguins: climate refugees from a distant past | Wiida Fourie-Basson (media: Faculty of Science) | <p><em>A new study on the paleo-historical geographic range of the endangered African penguin since the last Ice Age paints a grave picture of a species in steep decline.</em></p><p>Imagine the view from the western coastline of southern Africa during the Last Glacial Maximum (LGM) over twenty thousand years ago: in the distance you would see at least fifteen large islands – the largest 300 square kilometres in area – swarming with hundreds of millions of marine birds and penguin colonies.</p><p>Now imagine sea levels rising up to a hundred metres between fifteen to seven thousand years ago, gradually covering these large islands until only small hill tops and outcrops remained above water. Over the past 22 000 years this resulted in a tenfold reduction in suitable nesting habitat for African penguins, sending their population numbers into steep decline.</p><p>This is the paleo-historical picture of the geographical range of African penguins, created by scientists in the evolutionary genomics research group in the <a href="/english/faculty/science/botany-zoology/Pages/default.aspx">Department of Botany and Zoology</a> and the <a href="https://climate.sun.ac.za/">School for Climate Studies</a> at Stellenbosch University (SU). With this effort, they hope to provide new insight into the current vulnerability of the last remaining penguin species in Africa. </p><p><img src="/english/PublishingImages/Lists/dualnews/Edit/Penguins_FAW_300dpi-CMYK.jpg" alt="Penguins_FAW_300dpi-CMYK.jpg" style="margin:5px;width:705px;" /><br>The study, titled “<a href="https://www.tandfonline.com/doi/full/10.2989/1814232X.2023.2171126">A natural terminal Pleistocene decline of African penguin populations enhances their anthropogenic extinction risk</a>" was published in the <a href="https://www.tandfonline.com/toc/tams20/current"><em>African Journal of Marine Science</em></a> on 20 April 2023.<br></p><p>Dr Heath Beckett, first author of the article and postdoctoral fellow at SU's School for Climate Studies, says this paleo-historical image of multiple millions stands in stark contrast to the current reality of a post-1900 collapse of the African penguin population.</p><p>In 1910, Dassen Island (an island off the West Coast, about three square kilometres in area) was teeming with an estimated 1.45 million penguins. However, by 2011 South Africa's entire African penguin population collapsed to 21 000 breeding pairs, and by 2019 they further declined to only 13 600. Approximately 97% of the current population in South Africa is supported by only seven breeding colonies.</p><p>In May 2005 the International Union for the Conservation of Nature classified the African penguin as endangered. </p><p><img src="/english/PublishingImages/Lists/dualnews/My%20Items%20View/Dassenisland_banner.png" alt="Dassenisland_banner.png" class="ms-rtePosition-4" style="margin:5px;width:610px;" /><br></p><p><strong>Paleo-historical estimates of penguin population sizes</strong></p><p>So how did the southern and western coastlines of southern Africa look like during the last Ice Age? And what can it tell us about penguin population numbers?</p><p>As penguins prefer to breed on islands to escape mainland predators, the researchers used topographic maps of the ocean floor off the coast of southern Africa to identify potential historical islands lying at ten to 130 metres below current sea levels.</p><p>For islands to qualify as suitable for penguins they needed to offer protection from land-based predators and had to be surrounded by suitable foraging grounds for sardine and anchovy within a 20 kilometre radius. </p><p>Assuming that sea levels were much lower during the last Ice Age, they identified 15 large islands off the West Coast, the largest a 300 km<sup>2</sup> island lying 130 metres below the sea surface. Then taking into account rising sea levels over the past 15 000 to 7 000 years, they identified 220 islands which would have provided suitable nesting conditions for penguins, of which 216 are less than one km<sup>2</sup> in area, while some are as small as 30 m<sup>2</sup>, barely more than a rock. </p><p>Today the five largest islands off the West Coast of Southern Africa are Robben Island (~5 km<sup>2</sup>), Dassen Island (~3 km<sup>2</sup>), Possession Island (~ 1.8 km<sup>2</sup>) and Seal Island and Penguin Island (both below 1 km<sup>2</sup>). Possession, Seal and Penguin Island are all off the coast of Namibia. </p><p>Based on the earliest available population density estimates, they then calculated penguin population estimates based on available island area, assuming that penguins usually nest at most 500 metres from the shore.</p><p>Following this approach, they estimate that between 6.4 million and 18.8 million individuals could have occupied the southern Cape waters during the Last Glacial Maximum. Due to rising sea levels, however, 15 000 to seven thousand years ago, the habitat for the African penguins to nest on, went into a steep decline. </p><p>According to Dr Beckett, the main objective of the study is to show that there have been major changes in habitat availability over the last 22 000 years: “This could have had a massive effect on penguin populations. These populations are now experiencing additional human pressures on top of this in the form of climate change, habitat destruction and competition for food," he explains.</p><p><strong>Implications for conservation management</strong></p><p>While this finding raises grave concerns, the researchers argue that it also highlights the potential for a reserve of resilience in African penguins that may be leveraged for its conservation and management in an uncertain future. </p><p>Dr Beckett explains: “Changing sea levels would have necessitated the need for multiple relocations of breeding colonies of African penguins on time-scales of centuries, if not even shorter time-scales, and intense competition for breeding space as island habitat became greatly reduced in size. This historical flexibility of response provides some leeway for conservation managers to make available suitable breeding space, even in mainland sites, as long as appropriate nesting sites are made available". </p><p>According to Prof. Guy Midgley, interim director of SU's School for Climate Studies and a co-author, this millennial-scale set of selection pressures would have favoured strong colonisation ability in the species: “It's a total survivor and given half a chance, they will hang on. Island hopping saved it in the past, they know how to do this," he emphasised.</p><p>But even given the chance of relocation, how much more will it take to persist given the rise of modern human pressures? When competing against the commercial fishing industry and humanity in general for the same food source, penguins – and other marine life – may not stand a chance.</p><p>Therefore, “for any relocation measures to be successful," they warn, “sufficient access to marine food resources remain a vital element of a coordinated response to prevent extinction of the species".<br></p><p><strong>On the photo above:</strong> The African penguin population has declined from over one million breeding pairs in the early 1900's to less than 10 400 pairs today. These two photographs of Dassen Island off the West Coast of South Africa in the early 1900s and 2014 are a stark reminder of the near total population collapse of African penguins<em>. Images: Cherry Kearton and Christina Hagen, courtesy of the Two Oceans Aquarium, Cape Town, South Africa.</em></p><p><em></em><strong>Photo on the carousel: </strong>The African penguin (<em>Spheniscus demersus</em>) is known for its black and white plumage, black spots on its chest, and the characteristic “bray" resembling the sound of a donkey. It is the only species of penguin found on the African continent. The species are listed as Endangered on the International Union for Conservation of Nature (IUCN) Red List. With such a small number of birds in the wild, the population will be functionally extinct by 2035. <em>Image: Steve Benjamin CC-BY-ND</em></p><p><strong>Infographic:</strong> Jenny Frost</p><p><em></em></p><p><strong>Media interviews</strong></p><p>Prof. Guy Midgley, interim director of the School for Climate Studies at Stellenbosch University, <a href="mailto:gfmidgley@sun.ac.za">gfmidgley@sun.ac.za</a>, +27 82 569 2810 (WhatsApp only)</p><p>Dr Heath Beckett, postdoctoral fellow, School for Climate Studies at Stellenbosch University, <a href="mailto:hbeckett@sun.ac.za">hbeckett@sun.ac.za</a><br></p><p><br></p> |
| SU student off to University of Cambridge on Gates Cambridge scholarship | http://www.sun.ac.za/english/Lists/news/DispForm.aspx?ID=9872 | | SU student off to University of Cambridge on Gates Cambridge scholarship | Faculty of Science (media and communication) | <p></p><p>Gregor Feierabend, a postgraduate student in mathematics and computer science at Stellenbosch University (SU), has been awarded a <a href="https://www.gatescambridge.org/">Gates Cambridge scholarship</a> to pursue his MPhil in Computer Science at the University of Cambridge.</p><p>The Gates Cambridge Scholarship programme is the University of Cambridge's flagship international postgraduate scholarship proramme. According to a media release the programme was established in 2000 through a US$210 million donation from the Bill and Melinda Gates Foundation. This remains the largest single donation to a university in the United Kingdom. </p><p>Gregor, who originally hails from a small town near the Baltic Sea in northern Germany, has a special historical link with Stellenbosch University. His grandfather, Kurt-Rüdiger Kannenberg, was a mathematics lecturer at SU from 1960 until his death at age 43 in 1971. During this time, he supervised Henda Swart, the first student to obtain a PhD in mathematics at Stellenbosch University in 1971. </p><p>“My grandfather also used to work with the university's first IBM computer in the late 1960s. Even though I never met him personally, he is one of the reasons why I came to study mathematics at Stellenbosch," Gregor explains.</p><p>After completing school in Germany, Gregor first worked as a craftsman and social worker for a couple of years as he could not envision a career path in mathematics that would also involve creative work or have any social aspects. As a student at Stellenbosch University, however, he discovered how limited this view was: “At school, the focus lay on how to <em>use</em> mathematics, but at university, I learned how to <em>do</em> mathematics. Doing mathematics is, in fact, a very creative process, often of a collaborative nature," he explains.</p><p>In general, he enjoys thinking deeply and thoroughly about a topic at hand: “Mathematical thinking aligns very well with this and structures the thought process. Mathematics is both a tool and a field of research that is philosophically appealing and practically applicable. Computer science started as a branch of mathematics but has become independent of it. Nevertheless, mathematics is the foundation of all computer science, and it is this foundation that I am interested in."</p><p>He is excited to be part of the <span style="font-size:12pt;line-height:107%;font-family:calibri, sans-serif;"><a href="https://www.gatescambridge.org/about/news/gates-cambridge-class-of-2023-announced/">Gates
Cambridge class of 2023</a></span>: “The Gates Cambridge Trust offers many opportunities to interact with other scholars and to contribute in different ways. I think receiving an education comes with the responsibility to share knowledge and give something back to society. I can see myself thriving in such an environment and want to become part of this community."</p><p>His supervisor at Cambridge will be Prof. Marcelo Fiore, a researcher in the mathematical foundations of computer science. Gregor explains: “To think abstractly means to identify the essence of an idea and generalise concepts. The more general a theory, the wider its application in the real world. The fields I am currently most interested in are formal languages and proof assistants. Formal languages are encountered everywhere in computer science, in programming languages or network protocols. Proof assistants use mathematical logic to prove statements about software or network protocols. For example, one can verify the correctness of an end-to-end encryption protocol of instant messengers using such tools," he explains.</p><p>“Technology is all around us and used in nearly every academic discipline. Our everyday lives become increasingly dependent on it. I aim to make technology more secure and reliable by furthering research about the topics above," he concludes.<br></p><p><br></p> |
| Launch of STEM MentHER programme at SU | http://www.sun.ac.za/english/Lists/news/DispForm.aspx?ID=9861 | | Launch of STEM MentHER programme at SU | Faculty of Science (media and communication) | <p><br><br></p><p>The first cohort of STEM MentHER learners were paired with their mentors at Stellenbosch University (SU) during a special ceremony on Wednesday, 4 April 2023.</p><p>The <a href="https://questonline.org.za/applications-are-open-for-the-2023-stem-menther-programme/">STEM MentHER programme</a> is an initiative to guide and streamline female Grade 12 learners into the STEM fields of study: science, technology, engineering and mathematics. Successful candidates are mentored by female academics and postgraduate students, gain access to tailor-made programmes with the objective of becoming role models for other female learners in their environments.</p><p>The STEM MentHER programme was started by Dr Lungile Sithole and Dr Cerene Rathilal from the University of Johannesburg. The programme is now also rolled out at Stellenbosch University under the leadership of Dr Ronalda Benjamin, a lecturer in the Department of Mathematical Sciences, and is supported by the National Institute for Theoretical and Computational Sciences (NITheCS). The nine learners were selected amongst more than one hundred applicants from Cape schools.</p><p>During the ceremony Dr Benjamin encouraged the learners to make full use of their mentors: “I wish I had access to someone from university to get advice from while I was at school," she said. </p><p>Prof. Francesco Petruccione, interim director of NITheCS, said young scientists and engineers have the opportunity to shape the evolution of Artificial Intelligence tools such as ChatGPT: “Artificial Intelligence is pervasive and will shape everything. You should be part of the generation who shapes the evolution of this tool. These are exciting times for those who know how to use the tool (and not for those who are scared of it)".</p><p>In the closing remarks, Prof. Ingrid Rewitzky, head of the Department of Mathematical Sciences at SU, said students should not focus on singular moments of success or failure, but rather visualise their careers as a continuously evolving journey, adapting to challenges along the way and learning from failures in order to be better prepared the next time round: “It is a process. Throughout our lives we learn. Do what is in your hearts and embrace this opportunity," she concluded.</p><p>The learners and their mentors are:</p><p>Siphesihle Gama, Spine Road High School, to be mentored by Dr Kathleen Green, Agile Methodologies consultant; Raighaana Schroeder, Spine Road High School, to be mentored by Dr Shareefa Dalvi from the University of Cape Town; Rencha Hamman-Johnson, Hoërskool D.F. Malan, to be mentored by Dr Cara Haller from the Faculty of Engineering at SU; Saskia Human, Parel Vallei High School, mentored by) Dr Taskeen Ebrahim, Faculty of Engineering at SU; Stephanie McCreath, Parel Vallei High School, mentored by Anneri Aspeling, MSc student in Engineering, SU; Imaan Samuels, Parel Vallei High School, mentored by Dr Retha Heymann from the Faculty of Science at SU; Neo Ndlovu, Wynberg Girls' High School, mentored by Prof. Karin Howell from the Faculty of Science at SU; Kouthar Saliem, Wynberg Girls' High School, mentored by Ms Jacobie Mouton, computer scientist, and Catherine Wills, Wynberg Girls' High School, mentored by Dr Ronalda Benjamin.<br></p><p><br></p> |
| Valuable exchange of expertise on extracellular vesicle research | http://www.sun.ac.za/english/Lists/news/DispForm.aspx?ID=9858 | | Valuable exchange of expertise on extracellular vesicle research | Faculty of Science (media and communication) | <p>Mai Wageh, a PhD-student from McMaster University in Canada, recently spent six weeks in Prof. Kathy Myburgh's lab at Stellenbosch University (SU) to gain technical expertise in extracellular vesicle (EV) analysis.<br></p><p>The visit was made possible by a travel grant from the American College of Sports Medicine (ACSM). The Howard G. “Skip" Knuttgen International Travel Award encourages young scientists to undertake creative approaches to promote the acquisition of technical expertise and scientific knowledge through an international research learning programme at a host outside of Canada and the USA. </p><p>Prof. Myburgh is a Fellow of the ACSM (a requirement for hosting a student) and a leading expert in the emerging field of extracellular vesicle (EV) research. She also holds the <a href="/english/faculty/science/physiologicalsciences/research/muscle-research-group">South African research chair in Integrative Skeletal Muscle Physiology, Biology and Biotechnology</a> in SU's Department of Physiological Sciences.</p><p>Research activities in the field of extracellular vesicles (EVs) have exploded over the past two decades since researchers discovered that these nanoparticles, produced in their millions by all cells in the body, carry proteins and valuable genetic material important for intercellular communication. </p><p>However, preparing the samples for analysis is a technically demanding exercise. There is, for example, 10<sup>9</sup> billion EVs in one millilitre of blood. Once the particles have been isolated, they can be analysed by standard techniques such as flow cytometry.</p><p>Mai says the six weeks were fast-paced and productive: “My research focuses on sex differences in muscle damage and the role of underlying hormones. With the technical expertise I acquired, I can now also investigate sex-based differences in the role of extracellular vesicles after exercise, and teach others back home in our lab how to prepare EV samples for analysis".</p><p>According to Prof. Myburgh there was a good exchange of knowledge, since Mai also brought a lot of expertise with her from working in the Molecular Exercise Physiology and Muscle Aging Lab, led by Dr. Gianni Parise at McMaster University. This lab focuses on the role of exercise as an activator of muscle stem cells, or satellite cells, in younger and older adults to determine the effects of aging and possible interventions </p><p>According to Prof. Myburgh, the exchange benefited her students also learned from Mai's expertise in multi-component immunohistochemistry, a technique used to visualise and identify various factors in exercised muscle tissue including satellite cells, neutrophils (myeloperoxidase), alongside the resident components of the stem cell niche, i.e. muscle borders and existing nuclei in the muscle.<br></p><p><em>On the photo above: Mai Wageh and Prof. Kathy Myburgh. Photo: Wiida Fourie-Basson</em><br></p><p><br></p> |
| Scientists identify new benchmark for freezing point for water at -70 °C | http://www.sun.ac.za/english/Lists/news/DispForm.aspx?ID=9860 | | Scientists identify new benchmark for freezing point for water at -70 °C | Wiida Fourie-Basson (media: Faculty of Science) | <p>Scientists have discovered yet another amazing aspect of the weird and wonderful behaviour of water – this time when subjected to nanoscale confinement at sub-zero temperatures.<br></p><p>The finding that a crystalline substance can readily give up water at temperatures as low as -70 °C, published in the journal <a href="https://www.nature.com/articles/s41586-023-05749-7"><em>Nature</em></a> today, has major implications for the development of materials designed to extract water from the atmosphere.</p><p>A <a href="http://academic.sun.ac.za/barbour/Research.html">team</a> of supramolecular chemists at Stellenbosch University (SU), consisting of Dr Alan Eaby, Prof. Catharine Esterhuysen and Prof. Len Barbour, made this discovery while trying to understand the peculiar behaviour of a type of crystal that first piqued their interest about ten years ago.</p><p>“Scientists are currently adept at designing materials that can absorb water," Prof. Barbour explains. However, it is much harder to get those materials (we call them 'hydrates') to then release the water without having to supply energy in the form of heat. As we all know, energy is expensive and seldom completely 'green'.</p><p>The chemical compound in question was originally synthesised by Prof. Marcin Kwit, a specialist in organic stereochemistry at Adam Mickiewicz University in Poland. It was then crystallised and brought to Prof. Barbour's lab for further study by postdoctoral fellow Dr Agnieszka Janiak. This was mainly because of Prof. Barbour's interest in ring-shaped molecules and how they form channels when packed together in crystals.<img src="/english/PublishingImages/Lists/dualnews/My%20Items%20View/Capture.PNG" alt="Capture.PNG" class="ms-rtePosition-2" style="margin:5px;width:424px;" /><br></p><p>Dr Janiak noticed that the crystals were yellow on some days and red on others. It didn't take her long to figure out that the crystals would only turn red on days with humidity levels higher than 55%. When humidity levels fell below this level, the crystals would go back to being yellow.</p><p>“Not only was this behaviour rather unusual," Prof. Barbour explains, “it was also happening very fast. It seems the crystals were absorbing water as fast at high humidity as it was losing it again at low humidity. While we are familiar with materials designed to absorb water, it is highly unusual for a material that absorbs water easily to lose it equally easily".</p><p>Why do these crystals have such special properties? This question started a nearly ten-year investigation, which initially focused on explaining the mechanism behind the colour change. Theoretical modelling by Prof. Esterhuysen and MSc student Dirkie Myburgh showed that water uptake causes slight changes in the electronic properties of the crystals, causing them to turn red. With such remarkable properties, Prof. Barbour was convinced that the crystals would also have other interesting properties. </p><p>That is when PhD student Alan Eaby started dabbling with the material. Initially he had focused on room temperature studies for his MSc research but would later turn his attention to measuring properties at lower temperatures when he embarked on his PhD three years ago. He wanted to know how the crystals would behave when subjected to different temperatures and humidity levels: “I was intrigued by the colour change and wanted to explore what was happening at the atomic scale," he explains.</p><p>Having learnt about developing instruments and methods from Prof. Barbour, he embarked on employing non-standard techniques to understand the mechanisms of water uptake and release in the material.</p><p>One day, he observed something strange happening at temperatures below zero degrees Celsius. “I noticed that the crystal still changed colour at sub-zero temperatures. Initially I thought that there was something wrong with the experimental setup or the temperature controller, as crystal hydrates are not supposed to release water at such low temperatures," he explains.</p><p>After lots of conversations and coffee breaks with Profs Barbour and Esterhuysen, and tweaking the experimental setup several times, they realised that Alan's observations could be explained by the narrowness of the channels in the material. The channels in the crystal are only one nanometre wide – one thousandth the diameter of a human hair.</p><p>It was already known that, at the nanoscale, water can remain mobile within channels at temperatures below 0 °C. However, this study showed for the first time that such channels can also allow the uptake <em>and</em> release of water at temperatures far below its normal freezing point.</p><p>To understand this process, Dr Eaby undertook an extensive, systematic series of X-ray diffraction studies of the red and yellow crystals at different temperatures and humidities. This allowed him to construct a computer-generated 'movie', with atomic-scale resolution, of what happens to the channels upon cooling or heating, and in the presence or absence of water. These animations indicated that water molecules in the nanochannels move about freely until cooled to -70 °C, whereupon they undergo a “reversible structuring event" to resemble a glassy state. This 'glass transition' ultimately causes the water to become trapped in the material at temperatures below -70 °C.</p><p>Were it not for the colour-changing behaviour of the crystals in the first place, they would not have become aware of the ultralow temperature water loss capability: “Who knows," says Prof. Barbour, “there may be many other materials out there with the ability to absorb and release water at very low temperatures, such as metal-organic frameworks and covalent organic frameworks. </p><p>“We simply do not know about it because we have not been able to visualise it. Now that we do know that such behaviour is possible, it opens a whole new field of research and potential applications. Researchers can use this new information to identify other materials with similar properties, and also use the principles we've developed to fine tune the low-temperature release of water. This could lead to dramatic reductions in the energetic costs of atmospheric water harvesting, with implications for society and the environment." he concludes.</p><ul><li>The findings were published in the high-impact journal <em>Nature</em> on 13 April 2023 in the article “<a href="https://www.nature.com/articles/s41586-023-05749-7">Dehydration of a crystal hydrate at subglacial temperatures</a>". <br></li></ul><p><em>On the carousel above: Dr Alan Eaby, Prof. Catharine Esterhuysen and Prof. Len Barbour, supramolecular chemists in SU's Department of Chemistry and Polymer Science. Photo: Wiida Basson</em><br></p><p><em>Above left: </em><span class="ms-rteFontSize-2"><span style="line-height:107%;font-family:calibri, sans-serif;">Photomicographs of an initially red single
crystal shows how it transitions to yellow during dehydration at -20 °C.<em>
Image: Alan Eaby, first published in </em>Nature<em>, Vol. 616, 13 April 2022, by
Springer Nature</em></span></span></p><p><em><br></em></p> |
| “Invisible” gold hosted in sulphide minerals from Witwatersrand tailings dumps | http://www.sun.ac.za/english/Lists/news/DispForm.aspx?ID=9848 | | “Invisible” gold hosted in sulphide minerals from Witwatersrand tailings dumps | Wiida Fourie-Basson (media: Faculty of Science) | <p></p><p>A PhD-student in geometallurgy at Stellenbosch University (SU) has shown that there is still a significant fraction of “invisible" gold, inaccessible to traditional recovery methods, hosted in sulphide minerals in mine tailings dumps in the Witwatersrand region. </p><p>The mining of the Witwatersrand conglomerates, dating to 1885, has resulted in a massive accumulation of six billion tons of tailing materials. Due to historical processing inefficiencies, these tailings are currently being re-mined as a secondary gold source.</p><p>Steve Chingwaru, a PhD-student in geometallurgy at SU's <a href="/english/faculty/science/earthsciences">Department of Earth Sciences</a>, says his research delves into the complex interplay between geological and metallurgical factors: “The objective is to optimise the use of natural resources while minimising environmental impact. Through my work, I strive to develop innovative methods to extract valuable metals from mine tailings and turn waste into a valuable resource".<br></p><p style="text-align:left;"><img src="/english/PublishingImages/Lists/dualnews/My%20Items%20View/Steven%20Chingwaru%20profile.jpg" alt="Steven Chingwaru profile.jpg" class="ms-rtePosition-2" style="margin:5px;width:238px;" />Steve, who hails from Zimbabwe and finished his schooling in South Africa, says tailing dumps are not really a geological feature: “These dumps are man-made features and a historical artefact of our mining legacy. Historical mining of the Witwatersrand region focussed almost uniquely on the free or native gold endowment. The gold hosted in the sulphides has largely been overlooked and is deemed 'invisible' as it is not recoverable by conventional methods".</p><p>Working with samples from tailing dumps in Carletonville, Central Rand, Evander and Klerksdorp Goldfields, Steve used extensive in-situ laser ablation and acid digestion analyses to determine which minerals hosted most of the gold: “Among a separate comprising the more dense mineral phases, we found that arsenian pyrite and pyrite accounted for 65% of gold in the Klerksdorp samples, 78% of the gold in the Carletonville samples, and 85% of gold in the Evander samples".</p><p>Now that they understand where the gold is located, as well as its concentration and mode of occurrence, the next step is to design and develop an effective leaching method to extract the gold, and valuable by-products, from the pyrite. </p><p>Steve explains: “By separating out these sulphide fractions during the reprocessing stage, it will also remove sulphide-associated heavy metals such as Copper, Cobalt and Nickel. Not only are these economically valuable by-products, removal of sulphide minerals will also directly lessen the impact of acid mine drainage on the environment". </p><p>This unique intersection of paleo-geology and geometallurgy research is an exciting contribution emanating from the new <a href="/english/Lists/news/DispForm.aspx?ID=9514">African Rainbow Minerals research chair in GeoMetallurgy</a>, jointly held by Dr Bjorn von der Heyden from the Department of Earth Sciences, and Dr Margreth Tadie from the Department of Process Engineering. They are both Steve's study leaders and co-authors on the recently published article “<a href="https://www.nature.com/articles/s41598-023-30219-5">An underexploited invisible gold resource in the Archean sulphides of the Witwatersrand tailings dumps</a>", published in the journal <em>Nature Scientific Reports.</em></p><p><strong>Media interviews</strong></p><p>Steve Chingwaru, PhD student in Department of Earth Sciences, Stellenbosch University, <a href="mailto:20206771@sun.ac.za">20206771@sun.ac.za</a></p><p>Dr Bjorn von der Heyden, African Rainbow Minerals research chair in GeoMetallurgy, Department of Earth Sciences, Stellenbosch University, <a href="mailto:bvon@sun.ac.za">bvon@sun.ac.za</a></p><p>Dr Margreth Tadie, African Rainbow Minerals research chair in GeoMetallurgy, Department of Process Engineering, Stellenbosch University, <a href="mailto:mtadie@sun.ac.za">mtadie@sun.ac.za</a><br></p><p><em>On the photo: PhD student Steve Chingwaru in front of the Chamber of Mines Building at Stellenbosch University. Photo: Wiida Fourie-Basson</em></p><p><em>Image: https://www.drdgold.com/media-insights/photos/ergo?cat-2&os_image_id-39</em><br></p> |
| New DSc-study explores untapped potential of the human gut microbiome | http://www.sun.ac.za/english/Lists/news/DispForm.aspx?ID=9829 | | New DSc-study explores untapped potential of the human gut microbiome | Wiida Fourie-Basson (media: Fakulteit Natuurwetenskappe) | <p>The more we discover about the human gut microbiome and the gut-brain axis, the more questions arise concerning the influence that trillions of microorganisms have on the development of mental disorders and serious diseases such as cancer.<br></p><p>Indeed, in the not-so-distant future the gut microbiome will be integral to the development of novel therapeutics, probiotics and psychobiotics to treat gastro-intestinal disorders, improve cognitive functions, and prevent or treat mental disorders such as depression and schizophrenia, and conditions on the autism spectrum.<br></p><p>In a major review of this growing field of research, Prof. Leon Dicks, Distinguished Professor in Microbiology at Stellenbosch University (SU), states unequivocally that the full potential of the human gut microbiome, considered to be the second genome, has not yet been realised: “I am confident that we will be developing probiotics to treat dysbiosis (an imbalanced microbiome) and neuropsychiatric abnormalities," he writes in the conclusion.<br></p><p>Prof. Dicks will receive his Doctor of Science-degree during SU's March graduation ceremony this week. A Doctor of Science degree is awarded for published work of an exceptional standard, containing an original contribution to the advancement of knowledge and learning which has given the candidate international distinction in their field. </p><p>Prof. Dicks' dissertation is a compilation of health benefits offered by Lactic Acid Bacteria (LAB) and summarises findings from his research published over the past 35 years. Since 1998 he has contributed to 264 scientific papers and 25 book chapters on lactic acid bacteria, antimicrobial peptides and probiotics.<br></p><p>In summary, he has found that gut microbiota has an immense impact on the gut-brain axis and overall mental health, specifically in terms of anti-inflammatory responses. For example, probiotics have already been shown to alleviate psychiatric symptoms stemming from inflammation in individuals with mental health conditions such as bipolar disorder, schizophrenia, obsessive compulsive disorder (OCD) and individuals on the autism spectrum.<br></p><p>However, he warns, “our understanding of exactly <em>how</em> gut microorganisms control cognitive behaviour, mood and neuropsychiatric disorders remain limited."</p><p>Current thinking is that the ability of bacteria to communicate (by means of chemical signals, called 'quorum sensing'), may play a role in communication between the gut microbiome and the brain. The nature of this “communication" is not direct, but involves an intricate control system of chemical signalling and immune response to keep the gut microbiome in a balanced state.<br></p><p>Prof. Dicks explains: “The modulation, development and renewal of neurons in the enteric nervous system (which is in close interaction with our digestive system) are controlled by gut microbiota. The gut microbiota produces short-chain fatty acids, which adhere to fatty acid receptors on the surface of the intestinal epithelial cells and thus interact with neurons or enter the circulatory system. <br></p><p>“Gut bacteria are not only sensitive to physiological variations in the gastro-intestinal tract, but also to the signal received from the central nervous system via the Vagus nerve (which runs from your brain to your large intestine) and the enteric nervous system. Minor activation of the Vagus nerve results in drastic changes in the production of neurotransmitters, which affects digestion, leaky gut syndrome, peristalsis, and immune regulation. Fibres of the Vagus nerve are not in direct contact with the gut or intestinal microbiota. Instead, signals reach the gut microbiota via 100 to 500 million neurons from the enteric nervous system in the submucosa and myenteric plexus (a network of nerve fibres in the muscular layers of digestive organs) of the gut wall.<br></p><p>“From all these studies, it is evident the intestinal barrier is controlled by fine-tuned communications between gut microbes and the host immune system. The complexity of those interactions raises the question about the level of our current understanding and eventually explains why is has been, up to now, difficult to develop specific therapeutic targets," he writes. </p><p>Prof. Dicks has also done extensive research on the potential anticancer properties of bacteriocins. Almost all bacteria, human gut bacteria included, produce antimicrobial peptides to inhibit the growth of similar or closely related bacterial strains. In the same way, these peptides could be employed to inhibit the growth of cancerous cells. To date, however, despite several scientific reports and the patenting of three bacteriocins for their potential anti-cancer properties, we are still “a long way from understanding the efficacy of bacteriocins in anticancer therapy," Prof. Dicks writes.</p><p>However, progress in metagenomics (the study of genetic material recovered directly from environmental samples), proteomics (large-scale study of proteins), heterologous gene expressions and nanotechnology, combined with the use of Artificial Intelligence software, may lead to the discovery and design of novel anticancer molecules. (With heterologous gene expression, scientists use competent cells to express and harvest specific genes that do not naturally occur in their hosts).<br></p><p>According to Prof. Alf Botha, head of the Department of Microbiology and Dicks' study leader, the DSc-dissertation is a powerful synthesis of the best of our current understanding and knowledge of this important field: “It is a grand review with new and directional ideas and insights. It has again underlined the importance of this field, and will give direction to research across the medical, physiological and microbiological sciences." <br></p><p>According to one of the external examiners, Prof. Dicks “managed to consolidate a number of very complex ideas regarding the gut microbiome and the gut-brain axis into a 'coherent story', and as a researcher in this field, this has been refreshing and enlightening, and has given me some food for thought!"<br></p><p>Prof. Dicks will receive his DSc-degree during Stellenbosch University ninth graduation ceremony on Thursday, 30 March 2023. </p><p><em>On the photo: Prof. Leon Dicks with his wife, Sarina Dicks, and his research group in the Department of Microbiology at Stellenbosch University, celebrating the successful defence of his DSc-dissertation. The postgraduate students are, from left to right, Carla Joos, Carla Ritter, Ross Vermeulen, Diron Hurn, Anton DP van Staden, Wian Vermeulen en Tasnem Uheida and fellow researcher Dr Shelly Dean. Photo: Wiida Fourie-Basson</em></p><p><br></p> |
