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Curiosity about environmental changes drives Dr Katlego Mashiane’s PhD research

21 April 2023 | Story Leonie Bolleurs | Photo Supplied

Striving to make a difference in the field of biodiversity conservation, Dr Katlego Mashiane decided to pursue a PhD in Geography, focusing on the spatial modelling of grassland diversity and nutrients in subalpine environments. He received his PhD during the recent April graduation ceremonies on the Qwaqwa Campus.

In the small village of Ga-Mabotia about 25 km outside of Polokwane, Dr Katlego Mashiane grew up, surrounded by rocky mountains characterised by boulder outcrops, where he interacted with nature from an early age.

He recently obtained his PhD, majoring in Geography, from the University of the Free State (UFS), which was conferred on him during the April graduation ceremonies that took place on the UFS Qwaqwa Campus. The title of his dissertation is Grass nutrients estimation as an Indicator of rangeland quality using satellite remote.

Predicting the presence of biodiversity and nutrients in an area

Based on the principle that diverse grasslands tend to perform better, environmental changes threaten the resilience and services these grassland ecosystems provide. The study examined how many different types of plants and animals can be found at a particular place to enhance our understanding of the ecosystem’s value to humans, and that biodiversity loss will reduce these ecosystem services. Focusing on spatial modelling of grassland diversity, Dr Mashiane specifically investigated the influence of topography and remotely sensed satellite data on species richness and diversity in subalpine environments, and how they are affected by the availability of grass species. To determine this, he used a random forest machine-learning algorithm to find the best information in the data that could be used to estimate the levels of species richness, diversity, and nitrogen in a protected national conservation park.

His study discovered that some data types – such as the near-infrared variable and certain vegetation data (EVI and SAVI) – were especially useful for determining the number and variety of species in a certain area. With this information, scientists can create models that predict the presence of different types of biodiversity and nutrients in an area.

Playing a key role in protecting our natural assets

Equipped with this knowledge, one will be able to understand how to protect and preserve different types of biodiversity and promote the nutritional value of both plants and animals in the environment. “Land managers could use this information for conservation strategies,” states Dr Mashiane, who decided to pursue this study because he was curious about how environmental changes will affect species.

“Grasslands provide important ecosystem services underpinning human well-being, and therefore warrant our protection; I would like to play a role in protecting our natural assets and contribute to understanding our biomes, especially in the context of global change,” he says.

In the next five years, Dr Mashiane plans to pursue further research and mentor other students in his field of study.

News Archive

Nanotechnology breakthrough at UFS

2010-08-19

Ph.D students, Chantel Swart and Ntsoaki Leeuw

Scientists at the University of the Free State (UFS) made an important breakthrough in the use of nanotechnology in medical and biological research. The UFS team’s research has been accepted for publication by the internationally accredited Canadian Journal of Microbiology.

The UFS study dissected yeast cells exposed to over-used cooking oil by peeling microscopically thin layers off the yeast cells through the use of nanotechnology.

The yeast cells were enlarged thousands of times to study what was going on inside the cells, whilst at the same time establishing the chemical elements the cells are composed of. This was done by making microscopically small surgical incisions into the cell walls.

This groundbreaking research opens up a host of new uses for nanotechnology, as it was the first study ever in which biological cells were surgically manipulated and at the same time elemental analysis performed through nanotechnology. According to Prof. Lodewyk Kock, head of the Division Lipid Biotechnology at the UFS, the study has far reaching implications for biological and medical research.

The research was the result of collaboration between the Department of Microbial, Biochemical and Food Biotechnology, the Department of Physics (under the leadership of Prof. Hendrik Swart) and the Centre for Microscopy (under the leadership of Prof.Pieter van Wyk).

Two Ph.D. students, Chantel Swart and Ntsoaki Leeuw, overseen by professors Kock and Van Wyk, managed to successfully prepare yeast that was exposed to over-used cooking oil (used for deep frying of food) for this first ever method of nanotechnological research.

According to Prof. Kock, a single yeast cell is approximately 5 micrometres long. “A micrometre is one millionth of a metre – in laymen’s terms, even less than the diameter of a single hair – and completely invisible to the human eye.”

Through the use of nanotechnology, the chemical composition of the surface of the yeast cells could be established by making a surgical incision into the surface. The cells could be peeled off in layers of approximately three (3) nanometres at a time to establish the effect of the oil on the yeast cell’s composition. A nanometre is one thousandth of a micrometre.

Each cell was enlarged by between 40 000 and 50 000 times. This was done by using the Department of Physics’ PHI700 Scanning Auger Nanoprobe linked to a Scanning Electron Microscope and Argon-etching. Under the guidance of Prof. Swart, Mss. Swart en Leeuw could dissect the surfaces of yeast cells exposed to over-used cooking oil.

The study noted wart like outgrowths - some only a few nanometres in diameter – on the cell surfaces. Research concluded that these outgrowths were caused by the oil. The exposure to the oil also drastically hampered the growth of the yeast cells. (See figure 1)

Researchers worldwide have warned about the over-usage of cooking oil for deep frying of food, as it can be linked to the cause of diseases like cancer. The over-usage of cooking oil in the preparation of food is therefore strictly regulated by laws worldwide.

The UFS-research doesn’t only show that over-used cooking oil is harmful to micro-organisms like yeast, but also suggests how nanotechnology can be used in biological and medical research on, amongst others, cancer cells.

Figure 1. Yeast cells exposed to over-used cooking oil. Wart like protuberances/ outgrowths (WP) is clearly visible on the surfaces of the elongated yeast cells. With the use of nanotechnology, it is possible to peel off the warts – some with a diameter of only a few nanometres – in layers only a few nanometres thick. At the same time, the 3D-structure of the warts as well as its chemical composition can be established.

Media Release
Issued by: Mangaliso Radebe
Assistant Director: Media Liaison
Tel: 051 401 2828
Cell: 078 460 3320
E-mail: radebemt@ufs.ac.za
18 August 2010

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