Extensive admixture and selective pressure across the Sahel Belt

Genome-wide studies of African populations have the potential to reveal powerful insights into the evolution of our species, as these diverse populations have been exposed to intense selective pressures imposed by infectious diseases, diet, and environmental factors. Within Africa, the Sahel Belt extensively overlaps the geographical center of several endemic infections such as malaria, trypanosomiasis, meningitis, and hemorrhagic fevers. We screened 2.5 million single nucleotide polymorphisms in 161 individuals from 13 Sahelian populations, which together with published data cover Western, Central, and Eastern Sahel, and include both nomadic and sedentary groups. We confirmed the role of this Belt as a main corridor for human migrations across the continent. Strong admixture was observed in both Central and Eastern Sahelian populations, with North Africans and Near Eastern/Arabians, respectively, but it was inexistent in Western Sahelian populations. Genome-wide local ancestry inference in admixed Sahelian populations revealed several candidate regions that were significantly enriched for non-autochthonous haplotypes, and many showed to be under positive selection. The DARC gene region in Arabs and Nubians was enriched for African ancestry, whereas the RAB3GAP1/LCT/MCM6 region in Oromo, the TAS2R gene family in Fulani, and the ALMS1/NAT8 in Turkana and Samburu were enriched for non-African ancestry. Signals of positive selection varied in terms of geographic amplitude. Some genomic regions were selected across the Belt, the most striking example being the malaria-related DARC gene. Others were Western-specific (oxytocin, calcium, and heart pathways), Eastern-specific (lipid pathways), or even population-restricted (TAS2R genes in Fulani, which may reflect sexual selection).

Girls out of school. State, culture and education in poor rural Lao People's Democratic Republic

Tese de Doutoramento em Sociologia

Design of mechatronic system for handling bedridden people

Dissertação de mestrado em Engenharia Mecatrónica

Psychosocial factors associated with adherence to treatment and quality of life in people living with HIV/AIDS in Brazil

Objective: The objective of this article was to investigate the biopsychosocial factors that influence adherence to treatment and the quality of life of individuals who have been successfully following the HIV/AIDS treatment. Methods: It is a cross-sectional study carried out with 120 HIV positive participants in the south of Brazil. Among the variables studied, of note are: perceived stress, social support, symptoms of anxiety and depression and quality of life. Results: The results show that a moderate to high adherence to the treatment paired with a strong sense of social support indicate a higher quality of life. Conclusion: The combination of social support and antiretroviral treatment have an impact on physical conditions, improving immune response and quality of life.

A genetic perspective on African prehistory

The various genetic systems (mitochondrial DNA, the Y-chromosome and the genome-wide autosomes) indicate that Africa is the most genetically diverse continent in the world and the most likely place of origin for anatomically modern humans. However, where in Africa modern humans arose and how the current genetic makeup within the continent was shaped is still open to debate. Here, we summarize the debate and focus especially on the maternally inherited mitochondrial DNA (mtDNA) and a recently revised chronology for the African mtDNA tree. We discuss the possible origin of modern humans in southern, eastern or Central Africa; the possibility of a migration from southern to eastern Africa more than 100 ka, carrying lineages within mtDNA haplogroup L0; the evidence for a climate-change-mediated population expansion in eastern Africa involving mtDNA haplogroup L3, leading to the “out-of-Africa” migration around 70–60 ka; the re-population of North Africa from the Near East around 40–30 ka suggested by mtDNA haplogroups U6 and M1; the evidence for population expansions and dispersals across the continent at the onset of the Holocene ; and the impact of the Bantu dispersals in Central, eastern and southern Africa within the last few millennia.

The internet in young people's everyday life: listening to portuguese teens' voices

[Excerto] Children and young people today go about their lives in an increasingly mediatized fashion. Their daily lives are inhabited by a variety of media, ranging from the so-called new media to the more traditional ones, which have an impact on how they perceive, get to kno,v and represent the world, how they interact with others, how they build their identity, and how they study, have fun and organize their daily lives. The media ecosystem, namely the digit.:tl environments, opened up opportunities to communicate, participate, create and produce information. Apparently, children and young people now have more means and opportunities at their disposal to express and share their ideas, interests and opinions, but are they actually taking advantage of such potential? \'(that uses are they making of these means? Does the Internet, in fact, enable the younger generations to create a new communication culture of expression and participation (...)?

A Infância na latitude zero: as brincadeiras da criança 'global' africana

Tese de Doutoramento em Estudos da Criança (área de especialização em Sociologia da Infância).

A gestão do desempenho como prática de implementação participada de um plano estratégico: o caso do Banco de Moçambique

Dissertação de Mestrado em Políticas Desenvolvimento dos Recursos Humanos