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In 1954, Allison proposed that hemoglobin S (HbS) gene causes protection against fatal malaria. This would explain the high HbS gene frequency observed in certain regions hyperendemic for malaria, so-called "malaria hypothesis". This in silico study was conducted to examine the feasibility of the hypothesis under more realistic initial conditions, where a mutant gene with heterozygous advantage against malaria (e.g., HbS) was introduced in a group of Neolithic hunter-gatherers who decided to start agriculture nearby water where malaria killed a proportion of population. The tribe population size, number of children born to each woman in each generation, mortality from malaria and sickle cell disease, the protection factor provided by the gene carriers against malaria, the probability of mating between the members of the parent and offspring populations, population growth, and increased fertility in women heterozygous for HbS, were also considered. For effectively confer protection against malaria within the shortest possible period, the mutation needs to be happened in a small population. For a large population, the process would take around 100 generations (~ 2500 years) or more to provide an effective protection. Even then, the probability that the new gene could survive and propagate to future generations is about 35%. Conventional population genetics equations with differential or difference equations, give totally incorrect estimates of the gene frequency in small populations; discrete mathematics should be used, instead. After introduction of the advantageous mutation, the gene frequency increased until a steady state value. This value is far less than the gene frequency reported in certain tribes of Africa. It seems that the malaria hypothesis, per se, could not explain such a high observed gene frequency, unless HbS is associated with lower mortality from other causes too. [ABSTRACT FROM AUTHOR]

Includes six articles on the challenges for management development in the 21st century in the German-speaking nations (Avery, Donnenberg, Gick, Hilb), Baltic States (Manning, Poljeva), East Africa (Mitiku, Wallace), South Africa (McFarlin, Coster, Mogale-Pretorius), Vietnam (McDaniel, Schermerhorn, Cuoc), and Australia and New Zealand (Avery, Everett, Finkelde, Wallace). (SK)

Background: It has been shown that stimulation of innate immunity may provide temporary protection against a variety of infectious diseases. Malaria has been shown to induce a robust innate immune response. This study was conducted to test the hypothesis that if the cumulative number of cases diagnosed with COVID-19 per 100,000 population was correlated with the prevalence of malaria in African countries where both malaria and COVID-19 were prevalent. Methods: In this ecological study, the cumulative incidence of COVID-19 and the prevalence of malaria were compared in 53 African countries. A negative binomial regression analysis with the cumulative incidence of COVID-19 as the dependent variable, and the human development index (HDI) and the prevalence of malaria, as independent variables, were used. Results: The mean cumulative incidence of COVID-19 was 522 cases per 100,000. Each 0.1 unit increase in HDI was associated with 2.4-fold (95% confidence interval 1.8–3.1) increase in the cumulative incidence of COVID-19. Prevalence of malaria was also independently associated with the cumulative incidence; each 10% increase in the prevalence was associated with 28% (10–41%) decrease in the cumulative incidence of COVID-19. Conclusions: Malaria might protect people against SARS-CoV-2 through the stimulation of innate immunity. Stimulation of the innate immune system could be the first line of defense in the pandemic preparedness arsenal. [ABSTRACT FROM AUTHOR]

Despite abundant natural resources, Africa faces a bleak economic future, owing in large part to its inability to train capable managers. In this article I present a dynamic model of management education in Africa, based on extensive field research. Among the many variables comprised in the model, those of greatest relevance to aid-giving countries are the pre-university educational system, the strong Western influence in management curricula and teaching methods, the lack of facilities for providing practical experience, and the relationship between governments and universities. Knowledge of weaknesses in the system and of differences between the needs of African and Western management should make it possible to develop more effective management education programs in Africa. [ABSTRACT FROM AUTHOR]