Latest News Archive

Please select Category, Year, and then Month to display items
Previous Archive
05 September 2022 | Story Andrè Damons | Photo Andrè Damons
Prof Abdon Atangana
Prof Abdon Atangana, Professor of Applied Mathematics in the Institute for Groundwater Studies (IGS) and a highly cited mathematician for the years 2019-2021, says existing mathematical models are used to first fit collected data and then predict future events. It is for this reason he introduced a new concept that can be used to test whether the spread will have one or several waves.

With a new outbreak of the Ebola Virus Disease (EVD) reported this year in Democratic Republic of the Congo (DRC) – the 14th EVD outbreak in the country – researchers at the University of the Free State (UFS) introduced a new concept that can be used to test whether the spread will have one or several waves. They believe the focus should be to identify the source or the hosts of this virus for it to be a complete eradication. 

According to the Centers for Disease Control and Prevention (CDC), the Ministry of Health in the Democratic Republic of the Congo (DRC) declared an outbreak of Ebola in Mbandaka health zone, Equateur Province on April 23, 2022. EVD, formerly known as Ebola haemorrhagic fever, is a severe, often fatal illness affecting humans and other primates. The virus is transmitted to people from wild animals (such as fruit bats, porcupines and non-human primates) and then spreads in the human population through direct contact with the blood, secretions, organs or other bodily fluids of infected people, and with surfaces and materials (e.g. bedding, clothing) contaminated with these fluids, according to the World Health Organisation (WHO).
 
Prof Abdon Atangana, Professor of Applied Mathematics in the Institute for Groundwater Studies (IGS), says existing mathematical models are used to first fit collected data and then predict future events. Predictions help lawmakers to take decisions that will help protect their citizens and their environments. The outbreaks of COVID-19 and other infectious diseases have exposed the weakness of these models as they failed to predict the number of waves and in several instances; they failed to predict accurately day-to-day new infections, daily deaths and recoveries.

Solving the challenges of the current models

In the case of COVID-19 in South Africa, it is predicted that the country had far more infections than what was recorded, which is due to challenges faced by the medical facilities, poverty, inequality, and other factors. With Ebola in the DRC, data recorded are not far from reality due to the nature of the virus and its symptoms. However, the predictions show although some measures have been put in place in DRC and other places where the Ebola virus spread, they will still face some challenges in the future, as the virus will continue to spread but may have less impact. 

“To solve the challenges with the current models, we suggested a new methodology. We suggested that each class should be divided into two subclasses (Detected and undetected) and we also suggested that rates of infection, recovery, death and vaccination classes should be a function of time not constant as suggested previously. These rates are obtained from what we called daily indicator functions. For example, an infection rate should be obtained from recorded data with the addition of an uncertain function that represents non-recorded data (Here more work is still to be done to get a better approximation).

“I introduced a new concept called strength number that can be used to test whether the spread will have one or several waves. The strength number is an accelerative force that helps to provide speed changes, thus if this number is less than zero we have deceleration, meaning there will be a decline in the number of infections. If the number is positive, we have acceleration, meaning we will have an increase in numbers. If the number is zero, the current situation will remain the same,” according to Prof Atangana. 

To provide better prediction, he continues, reliable data are first fitted with the suggested mathematical model. This helps them to know if their mathematical model is replicating the dynamic process of the spread. The next step is to predict future events, to do this, we create three sub-daily indicator functions (minimum, actual, and maximum). These will lead to three systems, the first system represents the worst-case scenario, the second is the actual scenario, and the last is a best-case scenario.

Virus will continue to spread but with less impact

Using this method, Prof Atangana, a highly cited mathematician for the years 2019-2021, says he and Dr Seda Igret Araz, postdoctoral student, were able to predict that, although some measures have been put in place in DRC and other places where the Ebola virus spreads, they will still face some challenges in the future as the virus will continue to spread but may have less impact. 

To properly achieve the conversion from observed facts into mathematical formulations and to address these limitations, he had to ask fundamental questions such as what is the rate of infection, what is the strength of the infection, what are the crossover patterns presented by the spread, how can day-to-day new infected numbers be predicted and what differential operator should be used to model a dynamic process followed by the spread?

This approach was tested for several infectious diseases where we present the case of Ebola in Congo and Covid-19 in South Africa.  

News Archive

DF Malherbe Memorial Lecture
2005-05-19

DF Malherbe Memorial Lecture: Language and language activism in a time of transformation (summary)
Proff Hennie van Coller and Jaap Steyn

Language activism necessary for multilingualism
The awareness is growing that language activism will be needed to bring about a truly democratic multi-lingual society. What is quite clear is that a firm resolve must continuously resist the concentrated pressure on Afrikaans-medium schools (and universities) to allow themselves to be anglicised through becoming first parallel medium, then dual medium, and finally English medium institutions.

Proff Hennie van Coller and Jaap Steyn said this last night (Wednesday night) in the 24th DF Malherbe Memorial Lecture at the University of the Free State. Prof van Coller is head of the Department Afrikaans, Dutch, German and French at the UFS. Both are widely honoured for their contributions to Afrikaans and the promotion of Afrikaans.

They discussed three periods of transformation since 1902, and said about the current phase, which started in 1994:  “Besides all institutions and councils having to be representative of South Africa’s racial composition, places of education were required to open their doors. Quite rapidly this policy has had the result that schools and universities may be solely English medium, but not solely Afrikaans medium. Afrikaans medium institutions — if they claim the right to remain Afrikaans — are quickly branded racist, even though their student body may include all races.

“Education departments are presently exerting great pressure on Afrikaans medium schools to become double or parallel medium schools.  Parallel medium education is an equitable solution provided it can be sustained. Established parallel medium schools, such as Grey College in Bloemfontein, have catered even-handedly for English and Afrikaans speakers for decades. But the situation is different in the parallel medium (and still worse in the double medium) schools that spring up usually at the behest of a department of education.

“Afrikaans schools are converted almost over-night into parallel or dual medium schools without any additional personnel being provided. Depending on the social environment, a parallel medium school becomes reconstituted as a dual medium school on average in five to eight years, and dual medium school becomes an English-only school in two to three years. Some Afrikaans medium schools have become English medium in just three years.

“Though the Constitution recognises mono-lingual schools, officials in the provinces insist that Afrikaans schools become dual or parallel medium; English medium schools are left undisturbed. One must conclude that the tacit aim of the state is English as the sole official language, despite the lip-service paid to multi-lingualism, and the optimistic references to post-apartheid South Africa as a ‘rainbow’ nation.”

They said a recent study has shown that the 1 396 Afrikaans schools in the six provinces in 1993 have dwindled to 844. The fall off in the Free State is from 153 to 97; in the Western Cape from 759 to 564; in Gauteng from 274 to 155; in Mapumalanga from 90 to 3; in the North West from 82 to 13; and in Limpopo Province from 38 to 12.

They said the changes at universities, too, have been severe, as university staffs well know. Ten years ago there were five Afrikaans universities. Today there are none. The government demanded that all universities be open to all, which has meant that all universities have had to become English medium. And no additional funding was forthcoming for the changes. The government policy amounts to a language “tax” imposed on the Afrikaans community for using Afrikaans.

“Only when all schools (and universities) are English will the clamor cease. Academics and educationists are beginning to speak openly of forming pressure groups to save Afrikaans schools, and of using litigation as one of their methods. 59% of Afrikaans parents have said they would support strong action if Afrikaans were no longer a medium of instruction at schools.”

 

 


 

We use cookies to make interactions with our websites and services easy and meaningful. To better understand how they are used, read more about the UFS cookie policy. By continuing to use this site you are giving us your consent to do this.

Accept