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02 July 2019 | Story Leonie Bolleurs
Edwin Skhosana
Edwin Skhosana is working hard to become a successful and competent actuary one day. With him is his lecturer, Dr Michael von Maltitz.

Edwin Skhosana, an Actuarial Sciences student, was described by his lecturer, Dr Michael von Maltitz of the Department of Mathematical Statistics and Actuarial Science, as ‘very quiet’ in his Causal Inference class. 

This may sound like a compliment, but it’s not.

For Dr Von Maltitz, being quiet is definitely not encouraged – not with the new teaching methods applied in class.

“See, my class is all about engagement – getting the students to watch videos on the topics, read about the methods in question, and then come to class to grill me about things they don’t understand. This change in teaching method is extremely disconcerting for many Mathematical students, who have up until now only been taught in the ‘memorise-regurgitate’ form they had ever since the start of high school,” he explains.

Future success


“My goal is to get the students to a level of understanding where they can sit down with me or with an expert in the field and have a conversation about the Mathematical Statistics topics that I teach. This is a very difficult task in such a technical module, and few students ever feel comfortable enough to engage with me actively in class in this way,” Dr Von Maltitz points out. 

Edwin is working hard towards applying the skills and knowledge he has obtained at university to become a successful and competent actuary one day. 

An important turning point was when it dawned on him how the things discussed in class could find an important practical application in so many fields.  

“This suddenly drove a spontaneous fascination in my mind that led me to engage with Dr Von Maltitz,” the previously quiet Edwin explains.

And everything changed.

Desperate to learn

Dr Von Maltitz explains: “Edwin came to my office to ask some questions. The incredible thing was that he sat down, and a conversation about the Mathematics, the foundations, and the methods just flowed between us. I have seldom had such an insightful chat about my module with a student. It was like a cascade of information just fell into place for Edwin.”

Although he sometimes still experiences his studies as challenging and grapples to adapt to the various styles of lecturing from different lecturers, Edwin now has hope for his class in Causal Inference. 

“I think Dr Von Maltitz’s way of presenting in class is excellent. It is, however, hard to grasp if you are still anchored in the old way of cramming, because he wants you to understand and be able to apply what he teaches,” says Edwin.

“It was just wonderfully refreshing to see someone so desperate to learn something (rather than just wanting to get a degree), and then actually managing to turn around a bad semester mark into such a river of understanding,” Dr Von Maltitz concludes.

Dr Michael von Maltitz
Dr Micheal von Maltitz

News Archive

To tan or not to tan: a burning issue
2009-12-08

 Prof. Werner Sinclair

“Some evidence exists which implies that sunscreens could indeed be responsible for the dramatic rise in the incidence of melanoma over the past three decades, the period during which the use of sunscreens became very popular,” says Prof. Werner Sinclair, Head of the Department of Dermatology at the University of the Free State. His inaugural lecture was on the topic Sunscreens – Curse or Blessing?

Prof. Sinclair says the use of sunscreen preparations is widely advocated as a measure to prevent acute sunburn, chronic sun damage and resultant premature skin aging as well as skin malignancies, including malignant melanoma. There is inconclusive evidence to prove that these preparations do indeed achieve all of these claims. The question is whether these preparations are doing more harm than good?

He says the incidence of skin cancer is rising dramatically and these tumours are induced mostly by the ultra-violet rays.

Of the UV light that reaches the earth 90-95% belongs to the UVA fraction. UVC is normally filtered out by the ozone layer. UVB leads to sunburn while UVA leads to pigmentation (tanning). Because frequent sunburn was often associated with skin cancer, UVB was assumed, naively, to be the culprit, he says.

Exposure to sunlight induces a sense of well-being, increases the libido, reduces appetite and induces the synthesis of large amounts of vitamin D, an essential nutritional factor. The use of sunscreen creams reduces vitamin D levels and low levels of vitamin D have been associated with breast and colon cancer. Prof. Sinclair says the 17% increase in breast cancer from 1981 to 1991 parallels the vigorous use of sunscreens over the same period.

Among the risk factors for the development of tumours are a family history, tendency to freckle, more than three episodes of severe sunburn during childhood, and the use of artificial UV light tanning booths. He says it remains a question whether to tan or not. It was earlier believed that the main carcinogenic rays were UVB and that UVA merely induced a tan. The increase in UVA exposure could have severe consequences.

Prof. Sinclair says the UV light used in artificial tanning booths consists mainly of pure UVA which are highly dangerous rays. It has been estimated that six per cent of all melanoma deaths in the UK can be directly attributed to the use of artificial tanning lights. The use of an artificial tanning booth will double the melanoma risk of a person. “UVA is solely responsible for solar skin aging and it is ironical that tanning addicts, who want to look beautiful, are inflicting accelerated ageing in the process,” he says.

On the use of sunscreens he says it can prevent painful sunburn, but UVA-induced damage continues unnoticed. UVB blockers decrease vitamin D synthesis, which is a particular problem in the elderly. It also prevents the sunburn warning and therefore increases the UVA dosage that an individual receives. It creates a false sense of security which is the biggest problem associated with sunscreens.

Evidence obtained from the state of Queensland in Australia, where the heaviest and longest use of sunscreens occurred, boasted the highest incidence of melanoma in the world. A huge study in Norway has shown a 350% increase in melanoma for men and 440% for women. This paralleled the increase in the use of UVB blocking sunscreens while there was no change in the ozone layer. It did however, occur during that time when tanning became fashionable in Norway and there was an increase especially in artificial tanning.

Prof. Sinclair says: “We believe that sunscreen use does not directly lead to melanoma, but UVA exposure does. The Melanoma Epidemic is a reality. Sunscreen preparations are not the magical answer in the fight against melanoma and the irresponsible use of these preparations can worsen the problem.”

Media Release
Issued by: Mangaliso Radebe
Assistant Director: Media Liaison
Tel: 051 401 2828
Cell: 078 460 3320
E-mail: radebemt.stg@ufs.ac.za
7 December 2009

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