239 research outputs found

    Evolution of embryonic developmental period in the marine bird families Alcidae and Spheniscidae: roles for nutrition and predation?

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    Background: Nutrition and predation have been considered two primary agents of selection important in theevolution of avian life history traits. The relative importance of these natural selective forces in the evolution of avianembryonic developmental period (EDP) remain poorly resolved, perhaps in part because research has tended to focuson a single, high taxonomic-level group of birds: Order Passeriformes. The marine bird families Alcidae (auks) andSpheniscidae (penguins) exhibit marked variation in EDP, as well as behavioural and ecological traits ultimately linkedto EDP. Therefore, auks and penguins provide a unique opportunity to assess the natural selective basis of variation in akey life-history trait at a low taxonomic-level. We used phylogenetic comparative methods to investigate the relativeimportance of behavioural and ecological factors related to nutrition and predation in the evolution of avian EDP.Results: Three behavioural and ecological variables related to nutrition and predation risk (i.e., clutch size, activitypattern, and nesting habits) were significant predictors of residual variation in auk and penguin EDP based on modelspredicting EDP from egg mass. Species with larger clutch sizes, diurnal activity patterns, and open nests hadsignificantly shorter EDPs. Further, EDP was found to be longer among birds which forage in distant offshore waters,relative to those that foraged in near shore waters, in line with our predictions, but not significantly so.Conclusion: Current debate has emphasized predation as the primary agent of selection driving avian life historydiversification. Our results suggest that both nutrition and predation have been important selective forces in theevolution of auk and penguin EDP, and highlight the importance of considering these questions at lower taxonomicscales. We suggest that further comparative studies on lower taxonomic-level groups will continue to constructivelyinform the debate on evolutionary determinants of avian EDP, as well as other life history parameters

    Complete Haplotype Sequence of the Human Immunoglobulin Heavy-Chain Variable, Diversity, and Joining Genes and Characterization of Allelic and Copy-Number Variation

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    The immunoglobulin heavy-chain locus (IGH) encodes variable (IGHV), diversity (IGHD), joining (IGHJ), and constant (IGHC) genes and is responsible for antibody heavy-chain biosynthesis, which is vital to the adaptive immune response. Programmed V-(D)-J somatic rearrangement and the complex duplicated nature of the locus have impeded attempts to reconcile its genomic organization based on traditional B-lymphocyte derived genetic material. As a result, sequence descriptions of germline variation within IGHV are lacking, haplotype inference using traditional linkage disequilibrium methods has been difficult, and the human genome reference assembly is missing several expressed IGHV genes. By using a hydatidiform mole BAC clone resource, we present the most complete haplotype of IGHV, IGHD, and IGHJ gene regions derived from a single chromosome, representing an alternate assembly of ∼1 Mbp of high-quality finished sequence. From this we add 101 kbp of previously uncharacterized sequence, including functional IGHV genes, and characterize four large germline copy-number variants (CNVs). In addition to this germline reference, we identify and characterize eight CNV-containing haplotypes from a panel of nine diploid genomes of diverse ethnic origin, discovering previously unmapped IGHV genes and an additional 121 kbp of insertion sequence. We genotype four of these CNVs by using PCR in 425 individuals from nine human populations. We find that all four are highly polymorphic and show considerable evidence of stratification (Fst = 0.3–0.5), with the greatest differences observed between African and Asian populations. These CNVs exhibit weak linkage disequilibrium with SNPs from two commercial arrays in most of the populations tested

    Preparing to introduce new maternal immunizations in low- and lower-middle-income countries: A report from the Bill & Melinda Gates Foundation convening "Allies in Maternal and Newborn Care"; May 3-4, 2018.

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    New strategies will be critical to reduce infant mortality and severe morbidity - there are still 5.2 million newborn deaths and stillbirths each year. The decline in newborn mortality has not kept pace with the reduction in under-five deaths and is slowest in low- and lower-middle-income countries (LMICs). Maternal immunization is a promising intervention to protect infants when they are most vulnerable - in utero and their first few months of life, before they can receive their own vaccines. Successfully introducing new vaccines for pregnant women in LMICs will require collaboration between two fields - (1) immunization and (2) maternal, newborn and child health - that use different service delivery approaches, operate under different policy and funding paradigms, and are not always integrated. In May 2018, stakeholders from these distinct communities convened to identify challenges and opportunities associated with delivering new maternal immunizations. Participants agreed that antenatal care is a logical platform. However, in many resource-constrained settings, antenatal care providers are already overburdened, and most women do not receive the recommended number of antenatal visits. Implementing maternal immunization could help increase antenatal care attendance by offering an additional safe and effective intervention that women value. Substantial effort is needed to demonstrate the benefits of maternal immunization to decision-makers and providers, and to ensure that countries and health systems are ready for introduction. To that end, participants identified the following priorities: assure coherence of policies for introducing new vaccines for pregnant women and strengthen maternal health interventions; generate demand for existing, recommended, and new maternal vaccines; conduct socio-behavioral, health systems and implementation research to shape optimal vaccine delivery strategies; and strengthen antenatal and perinatal care quality. To achieve these aims, collaboration across fields will be essential. Given that new maternal vaccines are advancing in clinical development, time is of the essence

    Bodyweight Perceptions among Texas Women: The Effects of Religion, Race/Ethnicity, and Citizenship Status

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    Despite previous work exploring linkages between religious participation and health, little research has looked at the role of religion in affecting bodyweight perceptions. Using the theoretical model developed by Levin et al. (Sociol Q 36(1):157–173, 1995) on the multidimensionality of religious participation, we develop several hypotheses and test them by using data from the 2004 Survey of Texas Adults. We estimate multinomial logistic regression models to determine the relative risk of women perceiving themselves as overweight. Results indicate that religious attendance lowers risk of women perceiving themselves as very overweight. Citizenship status was an important factor for Latinas, with noncitizens being less likely to see themselves as overweight. We also test interaction effects between religion and race. Religious attendance and prayer have a moderating effect among Latina non-citizens so that among these women, attendance and prayer intensify perceptions of feeling less overweight when compared to their white counterparts. Among African American women, the effect of increased church attendance leads to perceptions of being overweight. Prayer is also a correlate of overweight perceptions but only among African American women. We close with a discussion that highlights key implications from our findings, note study limitations, and several promising avenues for future research

    Clinically actionable secondary findings in 130 triads from sub-Saharan African families with non-syndromic orofacial clefts

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    Abstract Introduction The frequency and implications of secondary findings (SFs) from genomic testing data have been extensively researched. However, little is known about the frequency or reporting of SFs in Africans, who are underrepresented in large‐scale population genomic studies. The availability of data from the first whole‐genome sequencing for orofacial clefts in an African population motivated this investigation. Methods In total, 130 case‐parent trios were analyzed for SFs within the ACMG SFv.3.0 list genes. Additionally, we filtered for four more genes (HBB, HSD32B, G6PD and ACADM). Results We identified 246 unique variants in 55 genes; five variants in four genes were classified as pathogenic or likely pathogenic (P/LP). The P/LP variants were seen in 2.3% (9/390) of the subjects, a frequency higher than ~1% reported for diverse ethnicities. On the ACMG list, pathogenic variants were observed in PRKAG (p. Glu183Lys). Variants in the PALB2 (p. Glu159Ter), RYR1 (p. Arg2163Leu) and LDLR (p. Asn564Ser) genes were predicted to be LP. Conclusion This study provides information on the frequency and pathogenicity of SFs in an African cohort. Early risk detection will help reduce disease burden and contribute to efforts to increase knowledge of the distribution and impact of actionable genomic variants in diverse populations
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