Search results for "africa"
showing 10 items of 962 documents
The Libyan Collections in FI (Herbarium Centrale Italicum and Webb Herbarium) and Studies on the Libyan Flora by R. Pampanini – Part 2
2016
This work is the continuation of Part 1, published in 2015, and comprises the reconstruction of the original collections of new taxa described by R. Pampanini and other botanists and, where possible, typification of the new names and taxonomical updating. The material studied for the most part concerns Libyan specimens held in the FI and FI-W herbaria but in some case also K, LD, MPU, P, PAD, PAL, ULT. Other material, which Pampanini studied in Florence was subsequently conserved in other herbaria. Specimens belonging to 21 families have been examined, from the Najadaceae to Zygophyllaceae. As well as typification, bibliographical data have been provided for those already typified. In this …
Evolution of lactase persistence: an example of human niche construction
2011
Niche construction is the process by which organisms construct important components of their local environment in ways that introduce novel selection pressures. Lactase persistence is one of the clearest examples of niche construction in humans. Lactase is the enzyme responsible for the digestion of the milk sugar lactose and its production decreases after the weaning phase in most mammals, including most humans. Some humans, however, continue to produce lactase throughout adulthood, a trait known as lactase persistence. In European populations, a single mutation (−13910*T) explains the distribution of the phenotype, whereas several mutations are associated with it in Africa and the Middle …
Ethnic differences in serum lipoproteins and their determinants in South African women.
2010
The objective of the study was to characterize ethnic differences in lipid levels and low-density lipoprotein (LDL) particle size and subclasses in black and white South African women and to explore the associations with insulin sensitivity (S(I)), body composition, and lifestyle factors. Fasting serum lipids and LDL size and subclasses, body composition (dual-energy x-ray absorptiometry), and S(I) (frequently sampled intravenous glucose tolerance test) were measured in normal-weight (body mass index25 kg/m(2)) black (n = 15) and white (n = 15), and obese (body mass index30 kg/m(2)) black (n = 13) and white (n = 13) women. Normal-weight and obese black women had lower triglycerides (0.59 +/…
Schistosoma haematobium Infection and CD4+ T-cell levels: A cross-sectional study of young South African women
2015
Schistosoma (S.) haematobium causes urogenital schistosomiasis and has been hypothesized to adversely impact HIV transmission and progression. On the other hand it has been hypothesized that HIV could influence the manifestations of schistosomiasis. In this cross-sectional study, we explored the association between urogenital S. haematobium infection and CD4 cell counts in 792 female high-school students from randomly selected schools in rural KwaZulu-Natal, South Africa. We also investigated the association between low CD4 cell counts in HIV positive women and the number of excreted schistosome eggs in urine. Sixteen percent were HIV positive and 31% had signs of urogenital schistosomiasis…
Reproductive health problems in rural South African young women: risk behaviour and risk factors
2018
Background South African young women continue to be vulnerable, with high prevalence of teenage pregnancy, HIV, sexually transmitted infections (STIs) and female genital schistosomiasis (FGS). This study seeks to examine the underlying factors that may be associated with these four adverse reproductive health outcomes. Methods In a cross-sectional study of 1413 sexually active of young women, we explored these four adverse reproductive health outcomes by considering socio-demographic factors, socio-economic factors, sexual risk behaviour, substance abuse and knowledge about reproductive health by using a questionnaire. Consenting participants were asked about previous pregnancies and were t…
Early experiences from one of the first treatment programs for chronic hepatitis B in sub-Saharan Africa
2017
Treatment for chronic hepatitis B (CHB) is virtually absent in sub-Saharan Africa. Here we present early experiences from a pilot program for treatment of CHB in Ethiopia. Adults (≥18 years) with CHB were included in a cohort study at St. Paul’s Hospital Millennium Medical College, Addis Ababa, from February 2015. The baseline assessment included liver function tests, viral markers and transient elastography (Fibroscan 402, Echosense, France). Logistic regression models were used to identify predictors of fibrosis. Tenofovir disoproxil fumarate (TDF) was initiated based on the European Association for the Study of the Liver (EASL) criteria, with some modifications. The initial 300 patients …
Prevalence of methylenetetrahydrofolate reductase 677T and 1298C alleles and folate status: a comparative study in Mexican, West African, and Europea…
2006
Background: Methylenetetrahydrofolate reductase (MTHFR) 677C→T polymorphism is heterogeneously distributed worldwide, with the highest and lowest frequencies of the T allele in Mexico and Africa, respectively, and a south-to-north gradient in Europe. Distribution of MTHFR 1298A→C is less well known. It has been hypothesized that 677T frequency could result in part from gene-nutrient interactions. Objective: The objective was to compare the association of 677T and 1298C alleles with plasma concentrations of homocysteine, folate, and vitamin B-12 in geographical areas with contrasting 677T allele frequencies. Design: Healthy young adults (n = 1:277) were recruited in Mexico City, the West Afr…
An integrated model of condom use in Sub-Saharan African youth: A meta-analysis.
2017
Objective: We tested an integrated social–cognitive model derived from multiple theories of the determinants of young people's condom use in Sub-Saharan Africa. The model comprised seven social–cognitive antecedents of condom use: Attitudes, norms, control, risk perceptions, barriers, intentions, and previous condom use. Method: We conducted a systematic search of studies including effects between at least one model construct and intended or actual condom use in young people from sub-Saharan African countries. Fifty-five studies comprising 72 independent data sets were included and subjected to random-effects meta-analysis. Demographic and methodological variables were coded as moderators. …
Perceived Racial/Ethnic Discrimination and Psychological Outcomes Among Adult International Adoptees in Finland: Moderating Effects of Social Support…
2015
Quantitative literature on international adoptees and racial/ethnic discrimination is lacking despite results in qualitative studies from Europe and the United States that have consistently indicated how racism constantly complicates adoptees' everyday lives. To advance the literature, the present study examined the prevalence of perceived racial/ethnic discrimination among 213 adult international adoptees in Finland (59.6% women and 40.4% men, mean age 24.1 years), and the association between perceived racial/ethnic discrimination and psychological well-being indicators, including psychological distress and sleeping problems. In addition, we examined social support and sense of coherence a…
Genome-Wide Association Studies of the PR Interval in African Americans.
2011
The PR interval on the electrocardiogram reflects atrial and atrioventricular nodal conduction time. The PR interval is heritable, provides important information about arrhythmia risk, and has been suggested to differ among human races. Genome-wide association (GWA) studies have identified common genetic determinants of the PR interval in individuals of European and Asian ancestry, but there is a general paucity of GWA studies in individuals of African ancestry. We performed GWA studies in African American individuals from four cohorts (n = 6,247) to identify genetic variants associated with PR interval duration. Genotyping was performed using the Affymetrix 6.0 microarray. Imputation was p…