2,378 research outputs found

    The genetic architecture underlying the evolution of a rare piscivorous life history form in brown trout after secondary contact and strong introgression

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    Identifying the genetic basis underlying phenotypic divergence and reproductive isolation is a longstanding problem in evolutionary biology. Genetic signals of adaptation and reproductive isolation are often confounded by a wide range of factors, such as variation in demographic history or genomic features. Brown trout ( ) in the Loch Maree catchment, Scotland, exhibit reproductively isolated divergent life history morphs, including a rare piscivorous (ferox) life history form displaying larger body size, greater longevity and delayed maturation compared to sympatric benthivorous brown trout. Using a dataset of 16,066 SNPs, we analyzed the evolutionary history and genetic architecture underlying this divergence. We found that ferox trout and benthivorous brown trout most likely evolved after recent secondary contact of two distinct glacial lineages, and identified 33 genomic outlier windows across the genome, of which several have most likely formed through selection. We further identified twelve candidate genes and biological pathways related to growth, development and immune response potentially underpinning the observed phenotypic differences. The identification of clear genomic signals divergent between life history phenotypes and potentially linked to reproductive isolation, through size assortative mating, as well as the identification of the underlying demographic history, highlights the power of genomic studies of young species pairs for understanding the factors shaping genetic differentiation

    Dark Matter Constraints from the Sagittarius Dwarf and Tail System

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    2MASS has provided a three-dimensional map of the >360 degree, wrapped tidal tails of the Sagittarius (Sgr) dwarf spheroidal galaxy, as traced by M giant stars. With the inclusion of radial velocity data for stars along these tails, strong constraints exist for dynamical models of the Milky Way-Sgr interaction. N-body simulations of Sgr disruption with model parameters spanning a range of initial conditions (e.g., Sgr mass and orbit, Galactic rotation curve, halo flattening) are used to find parameterizations that match almost every extant observational constraint of the Sgr system. We discuss the implications of the Sgr data and models for the orbit, mass and M/L of the Sgr bound core as well as the strength, flattening, and lumpiness of the Milky Way potential.Comment: 6 pages, 0 figures. Contribution to proceedings of ``IAU Symposium 220: Dark Matter in Galaxies'', eds. S. Ryder, D.J. Pisano, M. Walker, and K. Freema

    Association between musculoskeletal pain with social isolation and loneliness: analysis of the English Longitudinal Study of Ageing

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    Introduction: Musculoskeletal pain is a prevalent health challenge for all age groups worldwide, but most notably in older adults. Social isolation is the consequence of a decrease in social network size with a reduction in the number of social contacts. Loneliness is the psychological embodiment of social isolation and represents an individual’s perception of dissatisfaction in the quality or quantity of their social contacts. This study aims to determine whether a relationship exists between musculoskeletal pain and social isolation and loneliness. Methods: A cross-sectional analysis of the English Longitudinal Study of Ageing (ELSA) cohort was undertaken. ELSA is a nationally representative sample of the non-institutionalised population of individuals aged 50 years and over based in England. Data were gathered on social isolation through the ELSA Social Isolation Index, loneliness through the University of California, Los Angeles (UCLA) Loneliness Scale and musculoskeletal pain. Data for covariates included physical activity, depression score, socioeconomic status, access to transport and demographic characteristics. Logistic regression analyses were undertaken to determine the relationship between social isolation and loneliness with pain and the additional covariates. Results: A total of 9299 participants were included in the analysis. This included 4125 (44.4%) males, with a mean age of 65.8 years. There was a significant association where social isolation was lower for those in pain (odd ratio (OR): 0.87; 95% confidence intervals (CI): 0.75 to 0.99), whereas the converse occurred for loneliness where this was higher for those in pain (OR: 1.15; 95% CI: 1.01 to 1.31). Age, occupation, physical activity and depression were all associated with increased social isolation and loneliness. Conclusion: People who experience chronic musculoskeletal pain are at greater risk of being lonely, but at less risk of being socially isolated. Health professionals should consider the wider implications of musculoskeletal pain on individuals, to reduce the risk of negative health implications associated with loneliness from impacting on individual’s health and well-being

    Co-Occurrence and Characteristics of Patients With Axial Spondyloarthritis Who Meet Criteria for Fibromyalgia : Results From a UK National Register

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    The British Society for Rheumatology (BSR) Biologics Register in Ankylosing Spondylitis is funded by the BSR and they have receive funds for this from Pfizer, AbbVie and UCB. These companies receive advance copies of manuscripts and can provide comments but have no input into determining the topics for analysis, publication and no input into the work involved in this analysis. This analysis is part-funded by Arthritis Research UK (Grant No: 21378)Peer reviewedPublisher PD

    Natural polymorphism in the thrombospondin-related adhesive protein of Plasmodium falciparum

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    We have developed a typing system using natural sequence variation in the thrombospondin-related adhesive protein (TRAP) gene of Plasmodium falciparum. This method permits a haplotype to be assigned to any particular TRAP gene. We have applied this method to a hospital-based, case control-study in Mali. Previous sequence variation and conservation in TRAP has been confirmed. Particular TRAP haplotypes can be used as geographic hallmarks. Because of the high level of conflict between characters, we have examined the phylogenetic relationships between parasites using a network approach. Having received patient samples from urban and periurban areas of Bamako, the majority of haplotypes were closely related and distinct from TRAP sequences present in other continents. This suggests that the structure of TRAP can only tolerate a limited number of sequence variations to preserve its function but that this is sufficient to allow the parasite to evade the host's immune system until a long-lived immune response can be maintained. It may also reflect host genetics in that certain variants may escape the host immune response more efficiently than others. For vaccine design, sequences from the major regional variants may need to be considered in the production of effective subunit vaccines

    Limits on Superconductivity-Related Magnetization in Sr2_2RuO4_4 and PrOs4_4Sb12_{12} from Scanning SQUID Microscopy

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    We present scanning SQUID microscopy data on the superconductors Sr2RuO4 (Tc = 1.5 K) and PrOs4_4Sb12_{12} (Tc = 1.8 K). In both of these materials, superconductivity-related time-reversal symmetry-breaking fields have been observed by muon spin rotation; our aim was to visualize the structure of these fields. However in neither Sr2_2RuO4_4 nor PrOs4_4Sb12_{12} do we observe spontaneous superconductivity-related magnetization. In Sr2_2RuO4_4, many experimental results have been interpreted on the basis of a px±ipypx \pm ipy superconducting order parameter. This order parameter is expected to give spontaneous magnetic induction at sample edges and order parameter domain walls. Supposing large domains, our data restrict domain wall and edge fields to no more than ~0.1% and ~0.2% of the expected magnitude, respectively. Alternatively, if the magnetization is of the expected order, the typical domain size is limited to ~30 nm for random domains, or ~500 nm for periodic domains.Comment: 8 pages, 7 figures. Submitted to Phys. Rev.

    Feasibility of a randomized controlled trial of functional strength training for people between six months and five years after stroke: FeSTivaLS trial

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    Background: Functional Strength Training (FST) could enhance recovery late after stroke. The aim of this study was to evaluate the feasibility of a subsequent fully powered, randomized controlled trial. Methods: The study was designed as a randomized, observer-blind trial. Both interventions were provided for up to one hour a day, four days a week, for six weeks. Evaluation points were before randomization (baseline), after six weeks intervention (outcome), and six weeks thereafter (follow-up). The study took place in participants’ own homes. Participants (n = 52) were a mean of 24.4 months after stroke with a mean age of 68.3 years with 67.3% male. All had difficulty using their paretic upper (UL) and lower limb (LL). Participants were allocated to FST-UL or FST-LL by an independent randomization service. The outcome measures were recruitment rate, attrition rate, practicality of recruitment strategies, occurrence of adverse reactions, acceptability of FST, and estimation of sample size for a subsequent trial. Primary clinical efficacy outcomes were the Action Research Arm Test (ARAT) and the Functional Ambulation Categories (FAC). Analysis was conducted using descriptive statistics and thematic analysis of participants’ views of FST. A power calculation used estimates of clinical efficacy variance to estimate sample size for a subsequent trial. Results: The screening process identified 1,127 stroke survivors of whom 52 (4.6%) were recruited. The recruitment rate was higher for referral from community therapists than for systematic identification of people discharged from an acute stroke unit. The attrition rate was 15.5% at the outcome and follow-up time-points. None of the participants experienced an adverse reaction. The participants who remained in the study at outcome had received 68% of the total possible amount of therapy. Participants reported that their experience of FST provided a sense of purpose and involvement and increased their confidence in performing activities. The power calculation provides estimation that 150 participants in each group will be required for a subsequent clinical trial. Conclusions: This study found that a subsequent clinical trial was feasible with modifications to the recruitment strategy to be used
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