289 research outputs found

    Colony-specific differences in decadal longitudinal body composition of a capital-breeding marine top predator

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    he long‐term studies included in this paper were funded by the Natural Environment Research Council through the grant ‘SMRU Long‐term measurement of marine mammal population structure, dynamics and trophic interactions’, grant reference SMRU1001. PP was in receipt of NERC grant no. NE/G008930/1 and EsmĂ©e Fairbairn Foundation funding during the work. SCS was supported as a postdoctoral fellow in an EPSRC award to RK and PP.1. Capital breeding animals such as true seals (Phocidae) rely on accumulated body reserves to rear offspring. A mother's body composition at the start of a breeding episode may depend on recent environmental conditions and sets the resources available for the reproductive episode. 2.  At two grey seal (Halichoerus grypus) breeding colonies with contrasting demographic characteristics, factors influencing individual variation and temporal trends in the body composition (expressed as the lipid‐to‐protein mass ratio) of females were examined. 3.  Maternal reproductive expenditure, and the consequences for mothers and their pups, were investigated. 4.  Individual variation in postpartum maternal body composition was considerable. Mean values of 27% (±5%) lipid and 18% (±1%) protein were estimated by hydrogen isotope dilution. No evidence of age effects was detected. 5.  Mothers with a high lipid‐to‐protein mass ratio expended a higher proportion of lipid resources, conserved protein and returned with more protein the following year. 6.  Average maternal postpartum body composition was similar between the two colonies, but temporal patterns differed at one colony where pup production was decreasing from another where pup production was increasing. Mothers at the declining colony consistently weaned larger pups than mothers at the increasing colony across the range of mother sizes, but measures of maternal body composition did not predict pup weaning masses.PostprintPeer reviewe

    Inferring individual marine migration from otolith ecogeochemical signatures of a wide-ranging fish

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    Despite technical advances in archival tag attachment and functional longevity, long-term tracking of individuals of some fish species remains prohibitively difficult. Here we combined high resolution stable isotope sampling of otoliths, genetic assignment, growth increment analyses and a simple movement model to inform a hidden Markov model of the location of individual wild Atlantic salmon (Salmo salar L.) at sea. The model provided a reconstruction of North Atlantic migration for a species which is extremely difficult to track throughout its marine life-stage. We show that plausible emigration and return migration patterns can be achieved from wild fish. Simulations of simplified northward and westward movement patterns in the North Atlantic were used to quantify precision and accuracy of the model which differed between these two directional scenarios. Because otolith-derived migratory information does not rely on capture, release and subsequent recapture of the individual, this can be retrieved from any fish. Thus these techniques offer a powerful tool for improving our understanding of the processes that govern movement and survival of individual fish during a protracted and largely unobservable life-stage in the oceanic environment

    Precision and accuracy of Dahl-Lea back-calculated smolt lengths from adult scales of Atlantic salmon (Salmo salar L.)

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    Using tagged and recaptured Atlantic salmon Salmo salar (n = 106) the present analysis shows that the most commonly applied linear back-calculation method for estimating past length, the Dahl-Lea method, resulted in overestimation of the length of large smolts and underestimation of small smolts.  A correction equation (y = 0.53x + 6.23) for estimating true smolt length (y) from lengths back-calculated from adult scale measures (x) to account for these systematic discrepancies is proposed.PostprintPeer reviewe

    Association of protein function-altering variants with cardiometabolic traits:the strong heart study

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    Clinical and biomarker phenotypic associations for carriers of protein function-altering variants may help to elucidate gene function and health effects in populations. We genotyped 1127 Strong Heart Family Study participants for protein function-altering single nucleotide variants (SNV) and indels selected from a low coverage whole exome sequencing of American Indians. We tested the association of each SNV/indel with 35 cardiometabolic traits. Among 1206 variants (average minor allele count = 20, range of 1 to 1064), similar to 43% were not present in publicly available repositories. We identified seven SNV-trait significant associations including a missense SNV at ABCA10 (rs779392624, p= 8 x 10(-9)) associated with fasting triglycerides, which gene product is involved in macrophage lipid homeostasis. Among non-diabetic individuals, missense SNVs at four genes were associated with fasting insulin adjusted for BMI (PHIL, chr6:79,650,711, p= 2.1 x 10(-6); TRPM3, rs760461668, p= 5 x10(-8); SPTY2D1, rs756851199, p= 1.6 x 10(-8); and TSPO, rs566547284, p= 2.4 x 10(-6)). PHIL encoded protein is involved in pancreatic beta-cell proliferation and survival, and TRPM3 protein mediates calcium signaling in pancreatic beta-cells in response to glucose. A genetic risk score combining increasing insulin risk alleles of these four genes was associated with 53% (95% confidence interval 1.09, 2.15) increased odds of incident diabetes and 83% (95% confidence interval 1.35, 2.48) increased odds of impaired fasting glucose at follow-up. Our study uncovered novel gene-trait associations through the study of protein-coding variants and demonstrates the advantages of association screenings targeting diverse and high-risk populations to study variants absent in publicly available repositories

    Rebuilding the Post-Pandemic Economy

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    After suffering the worst economic shock since the Great Depression, the American economy is recovering in fits and starts. While many businesses are reopening their doors and thriving, continued uncertainty about the course of the virus, the inflation outlook, labor shortages, and many other factors are hampering a full return to normal activity. The COVID-19 pandemic reinforced and exacerbated many of the biggest structural economic challenges in our society. It precipitated the largest economic relief and stimulus spending in US history and transformed the way that millions of Americans live and work, with automation, e-commerce, and telework all playing a bigger role.The policy volume Rebuilding the Post Pandemic Economy examines important questions about how the post-pandemic economy will take shape. What are some initial lessons we can take away from the novel government programs that were deployed to provide economic relief and stimulus? How can we implement new infrastructure investments to maximize efficiency and equity, and best respond to the climate crisis? After a year of widespread school closures, what have we learned about the role of K-12 education in perpetuating or reducing social and economic inequities? And how should American trade policies evolve to promote economic recovery and strengthen America's role in the global economy

    Integrated Surveys of Neglected Tropical Diseases in Southern Sudan: How Much Do They Cost and Can They Be Refined?

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    Control of neglected tropical diseases (NTDs) is suggested to be more cost-effective when drugs are co-administered through a single integrated delivery system rather than separate systems. An essential prerequisite for such efficiency gains is sufficient geographical overlap of the targeted diseases – lymphatic filariasis (LF), onchocerciasis, schistosomiasis, soil-transmitted helminth infection and trachoma. Lack of data on geographical NTD distribution currently hampers the implementation of integrated control in many African countries. To generate the required data quickly and efficiently, integrated surveys of several NTDs simultaneously have been recommended. However, experience with integrated surveys is limited and requires additional research on cost and effectiveness to inform improvements in methodology and to guide scale-up. Here we analyse costs of the first integrated NTD survey round in Southern Sudan, generating average costs per implementation unit surveyed. Cost estimates are presented for use of the existing survey method and for modified versions. Key cost drivers were survey consumables and personnel, both of which are recurrent costs. These inputs could be reduced or put to more efficient use by modifying sampling for LF. To generate comparable cost estimates and identify key cost drivers in other settings we provide detailed cost data and guidance on how to replicate this work

    Genome-wide Association Study of Platelet Count Identifies Ancestry-Specific Loci in Hispanic/Latino Americans

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    Platelets play an essential role in hemostasis and thrombosis. We performed a genome-wide association study of platelet count in 12,491 participants of the Hispanic Community Health Study/Study of Latinos by using a mixed-model method that accounts for admixture and family relationships. We discovered and replicated associations with five genes (ACTN1, ETV7, GABBR1-MOG, MEF2C, and ZBTB9-BAK1). Our strongest association was with Amerindian-specific variant rs117672662 (p value = 1.16 × 10−28) in ACTN1, a gene implicated in congenital macrothrombocytopenia. rs117672662 exhibited allelic differences in transcriptional activity and protein binding in hematopoietic cells. Our results underscore the value of diverse populations to extend insights into the allelic architecture of complex traits
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