15 research outputs found
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High rate of extrapair paternity in a human population demonstrates diversity in human reproductive strategies.
Among nonhuman species, social monogamy is rarely accompanied by complete fidelity. Evolutionary theory predicts that the rate of extrapair paternity (EPP) should vary according to socioecological conditions. In humans, however, geneticists contend that EPP is negligible and relatively invariable. This conclusion is based on a limited set of studies, almost all of which describe European-descent groups. Using a novel, double-blind method designed in collaboration with a community of Himba pastoralists, we find that the rate of EPP in this population is 48%, with 70% of couples having at least one EPP child. Both men and women were very accurate at detecting cases of EPP. These data suggest that the range of variation in EPP across human populations is substantially greater than previously thought. We further show that a high rate of EPP can be accompanied by high paternity confidence, which highlights the importance of disaggregating EPP from the notion of "cuckoldry.
High rate of extrapair paternity in a human population demonstrates diversity in human reproductive strategies
Among nonhuman species, social monogamy is rarely accompanied by complete fidelity. Evolutionary theory predicts that the rate of extrapair paternity (EPP) should vary according to socioecological conditions. In humans, however, geneticists contend that EPP is negligible and relatively invariable. This conclusion is based on a limited set of studies, almost all of which describe European-descent groups. Using a novel, double-blind method designed in collaboration with a community of Himba pastoralists, we find that the rate of EPP in this population is 48%, with 70% of couples having at least one EPP child. Both men and women were very accurate at detecting cases of EPP. These data suggest that the range of variation in EPP across human populations is substantially greater than previously thought. We further show that a high rate of EPP can be accompanied by high paternity confidence, which highlights the importance of disaggregating EPP from the notion of “cuckoldry.
Evaluation of cytokine responses against novel Mtb antigens as diagnostic markers for TB disease
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Concurrent evaluation of cytokines improves the accuracy of antibodies against Mycobacterium tuberculosis antigens in the diagnosis of active tuberculosis
Data availability statement: All the important data relevant to this study was reported in the manuscript. Any additional data will be made available upon request from the corresponding author.Copyright © 2022 The Authors. Background:
Antibodies against mycobacterial proteins are highly specific, but lack sensitivity, whereas cytokines have been shown to be sensitive but not very specific in the diagnosis of tuberculosis (TB). We assessed combinations between antibodies and cytokines for diagnosing TB.
Methods:
Immuoglubulin (Ig) A and IgM antibody titres against selected mycobacterial antigens including Apa, NarL, Rv3019c, PstS1, LAM, “Kit 1” (MTP64 and Tpx)”, and “Kit 2” (MPT64, Tpx and 19 kDa) were evaluated by ELISA in plasma samples obtained from individuals under clinical suspicion for TB. Combinations between the antibody titres and previously published cytokine responses in the same participants were assessed for diagnosing active TB.
Results:
Antibody responses were more promising when used in combination (AUC of 0.80), when all seven antibodies were combined. When anti-“Kit 1”-IgA levels were combined with five host cytokine biomarkers, the AUC increased to 97% (92–100%) with a sensitivity of 95% (95% CI, 73–100%), and specificity of 88.5% (95% CI, 68.7–97%) achieved after leave-one-out cross validation.
Conclusion:
When used in combination, IgA titres measured with ELISA against multiple Mycobacterium tuberculosis antigens may be useful in the diagnosis of TB. However, diagnostic accuracy may be improved if the antibodies are used in combination with cytokines.This work was part of the EDCTP1 programme supported by the European Union (grant number IP_2009_32040, AE-TBC; awarded to GW). The project was also supported by the South African Government through the National Research Foundation (NRF, awarded to NC) and the South African Medical Research Council (SAMRC, postgraduate scholarship to RJ)
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Increased homozygosity due to endogamy results in fitness consequences in a human population.
Recessive alleles have been shown to directly affect both human Mendelian disease phenotypes and complex traits. Pedigree studies also suggest that consanguinity results in increased childhood mortality and adverse health phenotypes, presumably through penetrance of recessive mutations. Here, we test whether the accumulation of homozygous, recessive alleles decreases reproductive success in a human population. We address this question among the Namibian Himba, an endogamous agro-pastoralist population, who until very recently practiced natural fertility. Using a sample of 681 individuals, we show that Himba exhibit elevated levels of inbreeding, calculated as the fraction of the genome in runs of homozygosity (FROH). Many individuals contain multiple long segments of ROH in their genomes, indicating that their parents had high kinship coefficients. However, we do not find evidence that this is explained by first-cousin consanguinity, despite a reported social preference for cross-cousin marriages. Rather, we show that elevated haplotype sharing in the Himba is due to a bottleneck, likely in the past 60 generations. We test whether increased recessive mutation load results in observed fitness consequences by assessing the effect of FROH on completed fertility in a cohort of postreproductive women (n = 69). We find that higher FROH is significantly associated with lower fertility. Our data suggest a multilocus genetic effect on fitness driven by the expression of deleterious recessive alleles, especially those in long ROH. However, these effects are not the result of consanguinity but rather elevated background identity by descent
Recommended from our members
Increased homozygosity due to endogamy results in fitness consequences in a human population
Recessive alleles have been shown to directly affect both human Mendelian disease phenotypes and complex traits. Pedigree studies also suggest that consanguinity results in increased childhood mortality and adverse health phenotypes, presumably through penetrance of recessive mutations. Here, we test whether the accumulation of homozygous, recessive alleles decreases reproductive success in a human population. We address this question among the Namibian Himba, an endogamous agro-pastoralist population, who until very recently practiced natural fertility. Using a sample of 681 individuals, we show that Himba exhibit elevated levels of "inbreeding," calculated as the fraction of the genome in runs of homozygosity (FROH). Many individuals contain multiple long segments of ROH in their genomes, indicating that their parents had high kinship coefficients. However, we do not find evidence that this is explained by first-cousin consanguinity, despite a reported social preference for cross-cousin marriages. Rather, we show that elevated haplotype sharing in the Himba is due to a bottleneck, likely in the past 60 generations. We test whether increased recessive mutation load results in observed fitness consequences by assessing the effect of FROH on completed fertility in a cohort of postreproductive women (n = 69). We find that higher FROH is significantly associated with lower fertility. Our data suggest a multilocus genetic effect on fitness driven by the expression of deleterious recessive alleles, especially those in long ROH. However, these effects are not the result of consanguinity but rather elevated background identity by descent
Structural and electronic properties of Cu4O3 (paramelaconite): the role of native impurities
Limitations of seasonal pattern assessment questionnaire and development of shastun’s questionnaire for assessment of seasonal affective disorders, among namibian students in Moscow
Background. The environmental transition from one country to another after migration may be also associated with change in seasons, weather and climate as well as in psychosocial stress which may put a greater demand on physiology and metabolism of migrants that may predispose to cardiometabolic risk. This is commonly seen among students of the People’s Friendship University of Russia. Moscow. This study examines the validity of the newly developed questionnaire by Dr Shastun, for assessment of seasonal affective disorder (SAD) among students of Namibia studying at Moscow. Subjects and Methods. After approval by the Review board/ethics committee of Faculty of Medicine, People’s Friendship University of Russia, Moscow and written informed consent, subjects were recruited for this study. The study involved; Namibian students migrating to Russia while studying in Moscow. Of 87 students from Namibia, all of them volunteered to participate in the study. Seasonal affective disorder (SAD) was studied by Shastun’s questionnaire and Seasonal Pattern Assessment Questionnaire (SPAQ). The SPAQ is a brief, self-administered screening tool for seasonal affective disorder (SAD) which may have limitations. The criterion for diagnosis of SAD was a score of 11 or higher on this scale which means the highest level of SAD. The diagnosis SAD was also made by administering Shastun’s questionnaire. Results. The results indicate that clinical manifestations indicating SAD were rare while the students were in Namibia, which showed significant increase after migration to Russia and staying minimum for one year. Hypersomnia, overeating and carbohydrate craving were common manifestations of SAD. The prevalence of SAD by Shastun’s questionnaire was significantly lower compared to frequency of SAD by SPAQ, respectively (11.9% vs. 18.5%, P ≤ 0.05). The number of sunny days per year and the average annual temperature of the region of stay appear to be the most significant confounders and for the occurrence of cardiometabolic risks among students. Conclusions. Shastun’s questionnaire could be better instrument in accuracy in the diagnosis of SAD, because SPAQ has a few limitations. © Nova Science Publishers, Inc
Limitations of seasonal pattern assessment questionnaire and development of shastun’s questionnaire for assessment of seasonal affective disorders, among namibian students in Moscow
Background. The environmental transition from one country to another after migration may be also associated with change in seasons, weather and climate as well as in psychosocial stress which may put a greater demand on physiology and metabolism of migrants that may predispose to cardiometabolic risk. This is commonly seen among students of the People’s Friendship University of Russia. Moscow. This study examines the validity of the newly developed questionnaire by Dr Shastun, for assessment of seasonal affective disorder (SAD) among students of Namibia studying at Moscow. Subjects and Methods. After approval by the Review board/ethics committee of Faculty of Medicine, People’s Friendship University of Russia, Moscow and written informed consent, subjects were recruited for this study. The study involved; Namibian students migrating to Russia while studying in Moscow. Of 87 students from Namibia, all of them volunteered to participate in the study. Seasonal affective disorder (SAD) was studied by Shastun’s questionnaire and Seasonal Pattern Assessment Questionnaire (SPAQ). The SPAQ is a brief, self-administered screening tool for seasonal affective disorder (SAD) which may have limitations. The criterion for diagnosis of SAD was a score of 11 or higher on this scale which means the highest level of SAD. The diagnosis SAD was also made by administering Shastun’s questionnaire. Results. The results indicate that clinical manifestations indicating SAD were rare while the students were in Namibia, which showed significant increase after migration to Russia and staying minimum for one year. Hypersomnia, overeating and carbohydrate craving were common manifestations of SAD. The prevalence of SAD by Shastun’s questionnaire was significantly lower compared to frequency of SAD by SPAQ, respectively (11.9% vs. 18.5%, P ≤ 0.05). The number of sunny days per year and the average annual temperature of the region of stay appear to be the most significant confounders and for the occurrence of cardiometabolic risks among students. Conclusions. Shastun’s questionnaire could be better instrument in accuracy in the diagnosis of SAD, because SPAQ has a few limitations. © Nova Science Publishers, Inc
Chem4Energy – A Consortium of the Royal Society Africa Capacity Building Initiative
The Africa Capacity Building Initiative is a Royal Society programme funded by the then UK Department for International Development to develop collaborative research between scientists in sub-Saharan Africa and the UK. Initially, four institutions were involved in the Chem4Energy consortium: Cardiff University, UK, and three African partners, the Kwame Nkrumah University of Science and Technology, Ghana, the University of Namibia, and the University of Botswana, soon also including the Botswana International University of Science & Technology. The Chem4Energy research programme focussed on “New Materials for a Sustainable Energy Future: Linking Computation with Experiment”, aiming to deploy the synergy between state-of-the-art computational and experimental techniques to design and optimise new catalysts and semi-conductor materials for renewable energy applications, based on materials that are abundant and readily available in the African countries. The Chem4Energy consortium has achieved ambitious research goals, graduated 7 PhD students, and delivered a high-quality cross-disciplinary training programme in materials science and simulation techniques relevant to renewable energy applications. Since 2021, the extended consortium, including North-West University and the Centre for High Performance Computing in South Africa, has remained active through an annual Chem4Energy conference series, with the 4th meeting taking place in South Africa in March 2024