Pretoria, South Africa

University of Pretoria

www.up.ac.za/
Pretoria, South Africa

The University of Pretoria is a multi campus public research university located in Pretoria, the administrative and de facto capital of South Africa. The university was established in 1908 as the Pretoria campus of the Johannesburg based Transvaal University College and is the fourth South African insitution in continuous operation to be awarded university status. Wikipedia.

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Deprived of oxygen, naked mole-rats can survive by metabolizing fructose just as plants do, researchers report this week in the journal Science. Understanding how the animals do this could lead to treatments for patients suffering crises of oxygen deprivation, as in heart attacks and strokes. "This is just the latest remarkable discovery about the naked mole-rat -- a cold-blooded mammal that lives decades longer than other rodents, rarely gets cancer, and doesn’t feel many types of pain," says Thomas Park, professor of biological sciences at the University of Illinois at Chicago, who led an international team of researchers from UIC, the Max Delbrück Institute in Berlin and the University of Pretoria in South Africa on the study. In humans, laboratory mice, and all other known mammals, when brain cells are starved of oxygen they run out of energy and begin to die. But naked mole-rats have a backup: their brain cells start burning fructose, which produces energy anaerobically through a metabolic pathway that is only used by plants – or so scientists thought. In the new study, the researchers exposed naked mole-rats to low oxygen conditions in the laboratory and found that they released large amounts of fructose into the bloodstream. The fructose, the scientists found, was transported into brain cells by molecular fructose pumps that in all other mammals are found only on cells of the intestine. “The naked mole-rat has simply rearranged some basic building-blocks of metabolism to make it super-tolerant to low oxygen conditions,” said Park, who has studied the strange species for 18 years. At oxygen levels low enough to kill a human within minutes, naked mole-rats can survive for at least five hours, Park said. They go into a state of suspended animation, reducing their movement and dramatically slowing their pulse and breathing rate to conserve energy. And they begin using fructose until oxygen is available again. The naked mole-rat is the only known mammal to use suspended animation to survive oxygen deprivation. The scientists also showed that naked mole-rats are protected from another deadly aspect of low oxygen – a buildup of fluid in the lungs called pulmonary edema that afflicts mountain climbers at high altitude. The scientists think that the naked mole-rats’ unusual metabolism is an adaptation for living in their oxygen-poor burrows. Unlike other subterranean mammals, naked mole-rats live in hyper-crowded conditions, packed in with hundreds of colony mates. With so many animals living together in unventilated tunnels, oxygen supplies are quickly depleted.


News Article | April 21, 2017
Site: www.chromatographytechniques.com

Deprived of oxygen, naked mole-rats can survive by metabolizing fructose just as plants do, researchers report this week in the journal Science. Understanding how the animals do this could lead to treatments for patients suffering crises of oxygen deprivation, as in heart attacks and strokes. “This is just the latest remarkable discovery about the naked mole-rat — a cold-blooded mammal that lives decades longer than other rodents, rarely gets cancer, and doesn’t feel many types of pain,” says Thomas Park, professor of biological sciences at the University of Illinois at Chicago, who led an international team of researchers from UIC, the Max Delbrück Institute in Berlin and the University of Pretoria in South Africa on the study. In humans, laboratory mice, and all other known mammals, when brain cells are starved of oxygen they run out of energy and begin to die. But naked mole-rats have a backup: their brain cells start burning fructose, which produces energy anaerobically through a metabolic pathway that is only used by plants – or so scientists thought. In the new study, the researchers exposed naked mole-rats to low oxygen conditions in the laboratory and found that they released large amounts of fructose into the bloodstream. The fructose, the scientists found, was transported into brain cells by molecular fructose pumps that in all other mammals are found only on cells of the intestine. “The naked mole-rat has simply rearranged some basic building-blocks of metabolism to make it super-tolerant to low oxygen conditions,” said Park, who has studied the strange species for 18 years. At oxygen levels low enough to kill a human within minutes, naked mole-rats can survive for at least five hours, Park said. They go into a state of suspended animation, reducing their movement and dramatically slowing their pulse and breathing rate to conserve energy. And they begin using fructose until oxygen is available again. The naked mole-rat is the only known mammal to use suspended animation to survive oxygen deprivation. The scientists also showed that naked mole-rats are protected from another deadly aspect of low oxygen – a buildup of fluid in the lungs called pulmonary edema that afflicts mountain climbers at high altitude. The scientists think that the naked mole-rats’ unusual metabolism is an adaptation for living in their oxygen-poor burrows. Unlike other subterranean mammals, naked mole-rats live in hyper-crowded conditions, packed in with hundreds of colony mates. With so many animals living together in unventilated tunnels, oxygen supplies are quickly depleted.


Deprived of oxygen, naked mole-rats can survive by metabolizing fructose just as plants do, researchers report this week in the journal Science. Understanding how the animals do this could lead to treatments for patients suffering crises of oxygen deprivation, as in heart attacks and strokes. "This is just the latest remarkable discovery about the naked mole-rat -- a cold-blooded mammal that lives decades longer than other rodents, rarely gets cancer, and doesn’t feel many types of pain," says Thomas Park, professor of biological sciences at the University of Illinois at Chicago, who led an international team of researchers from UIC, the Max Delbrück Institute in Berlin and the University of Pretoria in South Africa on the study. In humans, laboratory mice, and all other known mammals, when brain cells are starved of oxygen they run out of energy and begin to die. But naked mole-rats have a backup: their brain cells start burning fructose, which produces energy anaerobically through a metabolic pathway that is only used by plants – or so scientists thought. In the new study, the researchers exposed naked mole-rats to low oxygen conditions in the laboratory and found that they released large amounts of fructose into the bloodstream. The fructose, the scientists found, was transported into brain cells by molecular fructose pumps that in all other mammals are found only on cells of the intestine. “The naked mole-rat has simply rearranged some basic building-blocks of metabolism to make it super-tolerant to low oxygen conditions,” said Park, who has studied the strange species for 18 years. At oxygen levels low enough to kill a human within minutes, naked mole-rats can survive for at least five hours, Park said. They go into a state of suspended animation, reducing their movement and dramatically slowing their pulse and breathing rate to conserve energy. And they begin using fructose until oxygen is available again. The naked mole-rat is the only known mammal to use suspended animation to survive oxygen deprivation. The scientists also showed that naked mole-rats are protected from another deadly aspect of low oxygen – a buildup of fluid in the lungs called pulmonary edema that afflicts mountain climbers at high altitude. The scientists think that the naked mole-rats’ unusual metabolism is an adaptation for living in their oxygen-poor burrows. Unlike other subterranean mammals, naked mole-rats live in hyper-crowded conditions, packed in with hundreds of colony mates. With so many animals living together in unventilated tunnels, oxygen supplies are quickly depleted.


News Article | April 20, 2017
Site: phys.org

Understanding how the animals do this could lead to treatments for patients suffering crises of oxygen deprivation, as in heart attacks and strokes. "This is just the latest remarkable discovery about the naked mole-rat—a cold-blooded mammal that lives decades longer than other rodents, rarely gets cancer, and doesn't feel many types of pain," says Thomas Park, professor of biological sciences at the University of Illinois at Chicago, who led an international team of researchers from UIC, the Max Delbrück Institute in Berlin and the University of Pretoria in South Africa on the study. In humans, laboratory mice, and all other known mammals, when brain cells are starved of oxygen they run out of energy and begin to die. But naked mole-rats have a backup: their brain cells start burning fructose, which produces energy anaerobically through a metabolic pathway that is only used by plants - or so scientists thought. In the new study, the researchers exposed naked mole-rats to low oxygen conditions in the laboratory and found that they released large amounts of fructose into the bloodstream. The fructose, the scientists found, was transported into brain cells by molecular fructose pumps that in all other mammals are found only on cells of the intestine. "The naked mole-rat has simply rearranged some basic building-blocks of metabolism to make it super-tolerant to low oxygen conditions," said Park, who has studied the strange species for 18 years. At oxygen levels low enough to kill a human within minutes, naked mole-rats can survive for at least five hours, Park said. They go into a state of suspended animation, reducing their movement and dramatically slowing their pulse and breathing rate to conserve energy. And they begin using fructose until oxygen is available again. The naked mole-rat is the only known mammal to use suspended animation to survive oxygen deprivation. The scientists also showed that naked mole-rats are protected from another deadly aspect of low oxygen - a buildup of fluid in the lungs called pulmonary edema that afflicts mountain climbers at high altitude. The scientists think that the naked mole-rats' unusual metabolism is an adaptation for living in their oxygen-poor burrows. Unlike other subterranean mammals, naked mole-rats live in hyper-crowded conditions, packed in with hundreds of colony mates. With so many animals living together in unventilated tunnels, oxygen supplies are quickly depleted. More information: "Fructose-driven glycolysis supports anoxia resistance in the naked mole-rat," Science (2017). science.sciencemag.org/cgi/doi/10.1126/science.aab3896


News Article | May 3, 2017
Site: www.eurekalert.org

Calls help maintain group cohesion and may provide listeners with cues about the producers Within a group of meerkats, call patterns vary with factors including sex, rank and reproductive season -- but not with stress hormones, according to a study published May 3, 2017 in the open-access journal PLOS ONE by Jelena Mausbach from University of Zurich, Switzerland; Marta Manser from University of Pretoria, South Africa; and colleagues. Meerkats live in family groups with social hierarchies, emitting contact calls that help maintain group cohesion during foraging. These calls are distinctive and have variable rates across individuals, but the influences on this behavior are unknown. To identify factors linked to call patterns, Mausbach, Manser and colleagues analyzed sound recordings and measured fecal stress hormones of 64 meerkats from 9 groups in the wild. The researchers found that call patterns vary with factors such as sex, social status, and reproductive season, suggesting that meerkat calls within a family group provide listeners with cues about the producers. For example, call rates were higher in dominant females and one-year-old males than in other individuals, and were up to five times more frequent during the reproductive season than during the non-reproductive season. However, call patterns were not linked to stress hormones, and the researchers speculate that this may reflect the fact that the calls studied were emitted during the relaxed context of foraging. In your coverage please use this URL to provide access to the freely available article in PLOS ONE: http://journals. Citation: Mausbach J, Braga Goncalves I, Heistermann M, Ganswindt A, Manser MB (2017) Meerkat close calling patterns are linked to sex, social category, season and wind, but not fecal glucocorticoid metabolite concentrations. PLoS ONE 12(5): e0175371. https:/ Funding: This study was funded by the Swiss National Science Foundation(grant no. 31003A_13676 to Marta B. Manser. The long term field site KMP was financed by Cambridge University, Zurich University and Earthwatch. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Competing Interests: The authors have declared that no competing interests exist.


News Article | April 27, 2017
Site: www.eurekalert.org

IMAGE:  Fukomys livingstoni is by Rebecca Gelertner of Near Bird Studios ( @NearBirdStudios ). view more Two new species of African mole-rat have been discovered by researchers at Queen Mary University of London (QMUL), together with colleagues in Tanzania and at the University of Pretoria. The species, formally described as Fukomys hanangensis and Fukomys livingstoni, were found around Mount Hanang and at Ujiji on the shores of Lake Tanganyika, both in Tanzania. The latter is named after Dr David Livingstone, as Ujiji is the site of the famous meeting in 1871 when Henry Morton Stanley found the explorer, who many thought to be dead, and uttered the famous words "Dr Livingstone, I presume?". The research was published in the journal PeerJ. African mole-rats are subterranean rodents that occur throughout sub-Saharan Africa. They have been widely studied because of the variation in their social and reproductive behaviours. More recently the naked mole-rat (Heterocephalus glaber) has also emerged as a model species for the study of healthy ageing, longevity and cancer resistance. Dr Chris Faulkes, from the School of Biological and Chemical Sciences and lead author of the paper, said: "We would like to find out more about the social behaviour of these new species - our initial studies indicate that they are cooperative breeders like others in their genus." "A clear understanding of African mole-rats' biodiversity and evolutionary relationships has become increasingly important, not least because there are many species in the family, but also because there are a number of genetically unique, distinctive populations that are limited in their distribution - two of which we now formally name and describe fully in our paper." Most of the species in this group of mole-rats (Fukomys) are to the West of the Great African Rift Valley, while these are to the East, out of their normal range. The researchers were therefore keen to characterise these populations and understand how and when they might have got to their current locations, as part of their wider studies on mole-rat biodiversity. The results revealed two distinct evolutionary lineages that constitute previously unnamed species. Detailed genetic analysis suggests that geological and volcanic activity isolated these populations subsequent to their earlier dispersal in to this part of East Africa. The broader scope of the research highlights how genetic data can be used to cross reference the timings of major geological events, and vice versa. Dr Faulkes added: "Our research argues that the biodiversity hotspots in this part of Africa can be understood in terms of landscape evolution in the form of tectonic activity [Rift Valley formation], climatic fluctuations and subsequent expansion and contraction of forest and savannah habitats."


News Article | May 26, 2017
Site: www.engineeringnews.co.za

The need for drastic economic reform cannot justify the widespread looting of state coffers, while the current state capture networks active in South Africa pose a dire threat to the country's long-term future. These were some of the sentiments shared by a group of academics gathered at the Wits Business School in Johannesburg on Thursday, where the State Capacity Research Project launched a scathing report on state capture and other problems currently facing South Africa and the ruling African National Congress (ANC). The report, titled Betrayal of the Promise: How South Africa is being stolen, is the result of a collaborative effort involving nine researchers from a range of local universities. The report is an academically-centered research paper that details how the likes of the powerful Gupta family have effectively hijacked key government institutions and state owned companies (SOC's). "We agree with the intentions of the governing party’s commitment to ‘radical economic transformation’, but in our view this is being used as an ideological smokescreen to mask the rent-seeking practices of the Zuma-centred power elite," the report's authors state in the document's preface. A selection of the report's contributors, along with Wits Vice Chancellor Adam Habib and other academics, addressed a packed lecture hall at the Wits Business School at the report's official launch. Some of the academics did not hold back when it came to identifying the perpetrators and enablers of state capture and corruption in South Africa. "There have been calls for us to give Malusi Gigaba a chance as the new finance minister. But the collapse of the state owned entities that we experience now is his work,” said Professor Mzukisi Qobo, a member of the South African research chair programme on African diplomacy and foreign policy at the University of Johannesburg. Qobo was referring to Gigaba's earlier stint as minister of public enterprises, a tenure that saw the Guptas land some of their first large deals at SOC's such as Transnet. Sithembile Mbete, a lecturer at the University of Pretoria's department of political sciences, claimed that the tentacles of state capture reaches so deep into the core of the ruling party and the government that only drastic changes on the political landscape could save South Africa from predatory rent-seekers such as the Guptas. "As a country we've outgrown the ANC. South Africa needs a new moral and ethical center that is not Luthuli House," said Mbete. Download the full Betrayal of the Promise report here.


Persad L.A.B.,University of Pretoria
Frontiers in Neuroscience | Year: 2011

Caffeine is the most widely used psychoactive stimulant with prevalent use across all age groups. It is a naturally occurring substance found in the coffee bean, tea leaf, the kola nut, cocoa bean. Recently there has been an increase in energy drink consumption leading to caffeine abuse, with aggressive marketing and poor awareness on the consequences of high caffeine use. With caffeine consumption being so common, it is vital to know the impact caffeine has on the body, as its effects can influence cardio-respiratory, endocrine, and perhaps most importantly neurological systems. Detrimental effects have being described especially since an over consumption of caffeine has being noted. This review focuses on the neurophysiological impact of caffeine and its biochemical pathways in the human body. © 2011 Persad.


Nel L.H.,University of Pretoria
Emerging Infectious Diseases | Year: 2013

Human rabies is an ancient disease but in modern times has primarily been associated with dog rabies-endemic countries of Asia and Africa. From an African perspective, the inevitable and tragic consequences of rabies require serious reflection of the factors that continue to drive its neglect. Established as a major disease only after multiple introductions during the colonial era, rabies continues to spread into new reservoirs and territories in Africa. However, analysis of reported data identified major discrepancies that are indicators of poor surveillance, reporting, and cooperation among national, international, and global authorities. Ultimately, the absence of reliable and sustained data compromises the priority given to the control of rabies. Appropriate actions and changes, in accordance to the One Health philosophy and including aspects such as synchronized, shared, and unified global rabies data reporting, will not only be necessary, but also should be feasible.


Grant
Agency: GTR | Branch: NERC | Program: | Phase: Research Grant | Award Amount: 456.50K | Year: 2016

The cooling of poly-component liquids, such as magma (and also ice-cream and salt- or sea-water), can drive solidification in a bewildering array of styles. Often the solid that forms is of a different composition from the liquid (e.g. pure ice from salt water). This means that the composition and temperature of the residual liquid is always changing during cooling, causing changes in the density of the liquid. These density changes can drive convection in the liquid, and can have profound effects on the way in which mass and heat are transported within the crystallising system. When cooling rates are gentle solidification occurs from the cold boundaries as when ice forms on the pond on a still winters day. In contrast, when cooling rates are very high, vigorous convection in the liquid can drive crystallization away from the cold boundaries, forming a flurry of crystallization in the swirling interior. In the context of bodies of molten rock (magma) the way convective motion can re-distribute mass has significant effects on the way the residual liquid changes composition. This plays a vital role in determining the final composition (and hence the explosivity) of any erupted lava flows. The style of crystallization also affects how quickly a magma conduit feeding a surface eruption will freeze sufficiently to prevent more magma travelling along it. A further important reason to understand how convection controls the way magmas evolve in crustal magma chambers is because the only way we can make deductions about processes occurring in the inaccessible deep Earth is by an examination of the composition of erupted lavas. The project will involve creating small-scale, bench-top analogues for real magma bodies using salt-water solutions. We will be able to control the cooling and solidification rates in our tanks and watch directly what happens and where the crystals are forming - something that is not possible in real magmas. We will compare our experimental results with natural examples of basaltic, magmatic intrusions by taking advantage of some recent new discoveries that mean we can decode the record of crystallization style left in fully-solidified basaltic intrusions and flows using details of grain shape, internal compositional variations and the spatial distribution of dense minerals. These microstructural markers will enable us to work out whether the liquid in the magma bodies convected or was static during solidification. These discoveries provide an exciting opportunity to make real progress in understanding the fundamental processes at work as these bodies cooled.

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