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Durban, South Africa

The University of KwaZulu-Natal or UKZN is a university with five campuses all located in the province of KwaZulu-Natal in South Africa. It was formed on 1 January 2004 after the merger between the University of Natal and the University of Durban-Westville. Wikipedia.


Chaplot V.,University of KwaZulu - Natal
Geomorphology | Year: 2013

Gully erosion is a worldwide matter of concern because of the irreversible losses of fertile land, which often have severe environmental, economic and social consequences. While most of the studies on the gullying process have investigated the involved mechanisms (either overland flow incision, seepage or piping erosion), only few have been conducted on the controlling factors of gully wall retreat, an important, if not the dominant, land degradation process and sediment source in river systems. In a representative 4.4km2 degraded area of the Drakensberg foothills (South Africa) the main objective of this study was to evaluate the relationship between the rate of gully bank retreat (GBR) and parent material, soil types and selected terrain attributes (elevation, specific drainage area, mean slope gradient, slope length factor, stream power index, compound topographic index and slope curvatures). The survey of gully bank retreat was performed during an entire hydrological year, from September 2007 to September 2008, using a network of pins (n=440 from 110 pits). Both the gully contours and pin coordinates were determined, using a GPS with a 0.5m horizontal accuracy (n=20,120). The information on the parent material and the soil types was obtained from field observations complemented by laboratory analysis, while terrain attributes were extracted from a 20m DEM generated from 5m interval contour lines. The average GBR value for the 6512m of gully banks found in the area was 0.049±0.0013my-1, which, considering bank height and soil bulk density, corresponded to an erosion rate of 2.30tonha-1y-1. There was no significant difference in GBR between sandstone and dolerite and between Acrisols and Luvisols. Despite a weak one-to-one correlation with the selected terrain attributes (r<0.2), a principal component analysis (PCA), the first two axes of which explained 68% of the data variability, pointed out that GBR was the highest at hillslope inflexion points (profile and plan slope curvatures close to zero), in the vicinity of the head cuts and for drainage areas up to 500m2, as both situations experience a high removal rate of the soil material produced from the gully bank collapse and protecting gullies from laterally retreating. These results could be used to digitally map the more active gully banks for the improved implementation of preventive measures of gully growth, if high resolution DEMs are available. There remained, however, a certain amount of unexplained variability in the data, that further research studies on the mechanisms and associated factors of control of GBR could help to address. © 2012 Elsevier B.V. Source


Schiestl F.P.,University of Zurich | Johnson S.D.,University of KwaZulu - Natal
Trends in Ecology and Evolution | Year: 2013

Because most plants rely on animals for pollination, insights from animal sensory ecology and behavior are essential for understanding the evolution of flowers. In this review, we compare and contrast three main types of pollinator responses to floral signals - receiver bias, 'adaptive' innate preferences, and associative learning - and discuss how they can shape selection on floral signals. We show that pollinator-mediated selection on floral signals can be strong and that the molecular bases of floral signal variation are often surprisingly simple. These new empirical and conceptual insights into pollinator-mediated evolution provide a framework for understanding patterns of both convergent (pollination syndromes) and advergent (floral mimicry) floral signal evolution. © 2013 Elsevier Ltd. Source


Biccard B.,University of KwaZulu - Natal
Anesthesia and Analgesia | Year: 2015

The Revised Cardiac Risk Index (RCRI) was incorporated into the American College of Cardiology/American Heart Association (ACC/AHA) recommendations for the preoperative evaluation of the cardiac patient for noncardiac surgery. The purpose of this review was to analyze studies on cardiovascular clinical risk prediction that had used the previous "standard best" model, the RCRI, as a comparator. This review aims to determine whether modification of the current risk factors or adoption of other risk factors or other risk indices would improve upon the discrimination of cardiac risk prediction when compared with the RCRI. This is necessary because recent risk prediction models have shown better discrimination for major adverse cardiac events, and the pre-eminence of the RCRI is now in question. There is now a need for a new "best standard"cardiovascular risk prediction model to supersede the RCRI. This is desirable because it would: (1) allow for a global standard of cardiovascular risk assessment; (2) provide a standard comparator in all risk prediction research; (3) result in comparable data collection; and (4) allow for individual patient data meta-analyses. This should lead to continued progress in cardiovascular clinical risk prediction. A review of the current evidence suggests that to improve the preoperative clinical risk stratification for adverse cardiac events, a new risk stratification model be built that maintains the clinical risk factors identified in the RCRI, with the following modifications: (1) additional glomerular filtration rate cut points (as opposed to a single creatinine cut point); (2) age; (3) a history of peripheral vascular disease; (4) functional capacity; and (5) a specific surgical procedural category. One would expect a substantial improvement in the discrimination of the RCRI with this approach. Although most noncardiac surgeries will benefit from a standard "generic" cardiovascular risk prediction model, there are data to suggest that patients with human immunodeficiency virus disease who are undergoing vascular surgery may benefit from specific cardiovascular risk prediction models. Copyright © 2015 International Anesthesia Research Society. Source


Mars M.,University of KwaZulu - Natal
Progress in Cardiovascular Diseases | Year: 2013

Telecardiology holds great promise for Africa, from tele-echocardiography and tele-ECG s, to home monitoring and text messaging for medication adherence monitoring. The burden of disease is great and there is an extreme shortage of health professionals. Telemedicine can provide access to scarce specialist care, improve the quality of care in rural areas and reduce the need for rural patients to travel to seek medical attention. International cross border service can alleviate the shortage of doctors. But telecardiology, and telemedicine uptake in general, has been poor in Africa. Legal and ethical issues around local and cross border telemedicine have not been resolved. The literature was reviewed and obstacles to telemedicine in Africa and current telemedicine activities in Africa, are described. There are few sustained telemedicine services in Africa with the exception of tele-education. There is an expectation that mobile phones will facilitate a range of telemedicine activities in Africa. Africa needs telemedicine. © 2013 Elsevier Inc. Source


Johnson S.D.,University of KwaZulu - Natal
Philosophical Transactions of the Royal Society B: Biological Sciences | Year: 2010

The flora of southern Africa has exceptional species richness and endemism, making it an ideal system for studying the patterns and processes of evolutionary diversification. Using a wealth of recent case studies, I examine the evidence for pollinator-driven diversification in this flora. Pollination systems, which represent available niches for ecological diversification, are characterized in southern Africa by a high level of ecological and evolutionary specialization on the part of plants, and, in some cases, by pollinators as well. These systems are asymmetric, with entire plant guilds commonly specialized for a particular pollinator species or functional type, resulting in obvious convergent floral evolution among guild members. Identified modes of plant lineage diversification involving adaptation to pollinators in these guilds include (i) shifts between pollination systems, (ii) divergent use of the same pollinator, (iii) coevolution, (iv) trait tracking, and (v) floral mimicry of different model species. Microevolutionary studies confirm that pollinator shifts can be precipitated when a plant species encounters a novel pollinator fauna on its range margin, and macroevolutionary studies confirm frequent pollinator shifts associated with lineage diversification. As Darwin first noted, evolutionary specialization for particular pollinators, when resulting in ecological dependency, may increase the risk of plant extinction. I thus also consider the evidence that disturbance provokes pollination failure in some southern African plants with specialized pollination systems. © 2010 The Royal Society. Source

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