1,542 research outputs found
Cooling of Dark-Matter Admixed Neutron Stars with density-dependent Equation of State
We propose a dark-matter (DM) admixed density-dependent equation of state
where the fermionic DM interacts with the nucleons via Higgs portal. Presence
of DM can hardly influence the particle distribution inside neutron star (NS)
but can significantly affect the structure as well as equation of state (EOS)
of NS. Introduction of DM inside NS softens the equation of state. We explored
the effect of variation of DM mass and DM Fermi momentum on the NS EOS.
Moreover, DM-Higgs coupling is constrained using dark matter direct detection
experiments. Then, we studied cooling of normal NSs using APR and DD2 EOSs and
DM admixed NSs using dark-matter modified DD2 with varying DM mass and Fermi
momentum. We have done our analysis by considering different NS masses. Also DM
mass and DM Fermi momentum are varied for fixed NS mass and DM-Higgs coupling.
We calculated the variations of luminosity and temperature of NS with time for
all EOSs considered in our work and then compared our calculations with the
observed astronomical cooling data of pulsars namely Cas A, RX J0822-43, 1E
1207-52, RX J0002+62, XMMU J17328, PSR B1706-44, Vela, PSR B2334+61, PSR
B0656+14, Geminga, PSR B1055-52 and RX J0720.4-3125. It is found that APR EOS
agrees well with the pulsar data for lighter and medium mass NSs but cooling is
very fast for heavier NS. For DM admixed DD2 EOS, it is found that for all
considered NS masses, all chosen DM masses and Fermi momenta agree well with
the observational data of PSR B0656+14, Geminga, Vela, PSR B1706-44 and PSR
B2334+61. Cooling becomes faster as compared to normal NSs in case of
increasing DM mass and Fermi momenta. It is infered from the calculations that
if low mass super cold NSs are observed in future that may support the fact
that heavier WIMP can be present inside neutron stars.Comment: 24 Pages, 15 Figures and 2 Tables. Version accepted in The European
Physical Journal
Trade-Offs Between Reducing Complex Terminology and Producing Accurate Interpretations from Environmental DNA: Comment on “Environmental DNA: What\u27s behind the term?” by Pawlowski et al., (2020)
In a recent paper, “Environmental DNA: What\u27s behind the term? Clarifying the terminology and recommendations for its future use in biomonitoring,” Pawlowski et al. argue that the term eDNA should be used to refer to the pool of DNA isolated from environmental samples, as opposed to only extra-organismal DNA from macro-organisms. We agree with this view. However, we are concerned that their proposed two-level terminology specifying sampling environment and targeted taxa is overly simplistic and might hinder rather than improve clear communication about environmental DNA and its use in biomonitoring. This terminology is based on categories that are often difficult to assign and uninformative, and it overlooks a fundamental distinction within eDNA: the type of DNA (organismal or extra-organismal) from which ecological interpretations are derived
Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis
BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London
Sedimentary Environment Influences the Effect of an Infaunal Suspension Feeding Bivalve on Estuarine Ecosystem Function
The suspension feeding bivalve Austrovenus stutchburyi is a key species on intertidal sandflats in New Zealand, affecting the appearance and functioning of these systems, but is susceptible to several environmental stressors including sedimentation. Previous studies into the effect of this species on ecosystem function have been restricted in space and time, limiting our ability to infer the effect of habitat change on functioning. We examined the effect of Austrovenus on benthic primary production and nutrient dynamics at two sites, one sandy, the other composed of muddy-sand to determine whether sedimentary environment alters this key species' role. At each site we established large (16 m2) plots of two types, Austrovenus addition and removal. In winter and summer we deployed light and dark benthic chambers to quantify oxygen and nutrient fluxes and measured sediment denitrification enzyme activity to assess denitrification potential. Rates of gross primary production (GPP) and ammonium uptake were significantly increased when Austrovenus was added, relative to removed, at the sandy site (GPP, 1.5 times greater in winter and summer; ammonium uptake, 8 times greater in summer; 3-factor analysis of variance (ANOVA), p<0.05). Denitrification potential was also elevated in Austrovenus addition plots at the sandy site in summer (by 1.6 times, p<0.1). In contrast, there was no effect of Austrovenus treatment on any of these variables at the muddy-sand site, and overall rates tended to be lower at the muddy-sand site, relative to the sandy site (e.g. GPP was 2.1 to 3.4 times lower in winter and summer, respectively, p<0.001). Our results suggest that the positive effects of Austrovenus on system productivity and denitrification potential is limited at a muddy-sand site compared to a sandy site, and reveal the importance of considering sedimentary environment when examining the effect of key species on ecosystem function
Current issues in medically assisted reproduction and genetics in Europe: research, clinical practice, ethics, legal issues and policy. European Society of Human Genetics and European Society of Human Reproduction and Embryology.
In March 2005, a group of experts from the European Society of Human Genetics and European Society of Human Reproduction and Embryology met to discuss the interface between genetics and assisted reproductive technology (ART), and published an extended background paper, recommendations and two Editorials. Seven years later, in March 2012, a follow-up interdisciplinary workshop was held, involving representatives of both professional societies, including experts from the European Union Eurogentest2 Coordination Action Project. The main goal of this meeting was to discuss developments at the interface between clinical genetics and ARTs. As more genetic causes of reproductive failure are now recognised and an increasing number of patients undergo testing of their genome before conception, either in regular health care or in the context of direct-to-consumer testing, the need for genetic counselling and preimplantation genetic diagnosis (PGD) may increase. Preimplantation genetic screening (PGS) thus far does not have evidence from randomised clinical trials to substantiate that the technique is both effective and efficient. Whole-genome sequencing may create greater challenges both in the technological and interpretational domains, and requires further reflection about the ethics of genetic testing in ART and PGD/PGS. Diagnostic laboratories should be reporting their results according to internationally accepted accreditation standards (International Standards Organisation - ISO 15189). Further studies are needed in order to address issues related to the impact of ART on epigenetic reprogramming of the early embryo. The legal landscape regarding assisted reproduction is evolving but still remains very heterogeneous and often contradictory. The lack of legal harmonisation and uneven access to infertility treatment and PGD/PGS fosters considerable cross-border reproductive care in Europe and beyond. The aim of this paper is to complement previous publications and provide an update of selected topics that have evolved since 2005
LRP10 interacts with SORL1 in the intracellular vesicle trafficking pathway in non-neuronal brain cells and localises to Lewy bodies in Parkinson's disease and dementia with Lewy bodies
Loss-of-function variants in the low-density lipoprotein receptor-related protein 10 (LRP10) gene have been associated with autosomal-dominant Parkinson's disease (PD), PD dementia, and dementia with Lewy bodies (DLB). Moreover, LRP10 variants have been found in individuals diagnosed with progressive supranuclear palsy and amyotrophic lateral sclerosis. Despite this genetic evidence, little is known about the expression and function of LRP10 protein in the human brain under physiological or pathological conditions. To better understand how LRP10 variants lead to neurodegeneration, we first performed an in-depth characterisation of LRP10 expression in post-mortem brains and human-induced pluripotent stem cell (iPSC)-derived astrocytes and neurons from control subjects. In adult human brain, LRP10 is mainly expressed in astrocytes and neurovasculature but undetectable in neurons. Similarly, LRP10 is highly expressed in iPSC-derived astrocytes but cannot be observed in iPSC-derived neurons. In astrocytes, LRP10 is present at trans-Golgi network, plasma membrane, retromer, and early endosomes. Interestingly, LRP10 also partially co-localises and interacts with sortilin-related receptor 1 (SORL1). Furthermore, although LRP10 expression and localisation in the substantia nigra of most idiopathic PD and DLB patients and LRP10 variant carriers diagnosed with PD or DLB appeared unchanged compared to control subjects, significantly enlarged LRP10-positive vesicles were detected in a patient carrying the LRP10 p.Arg235Cys variant. Last, LRP10 was detected in Lewy bodies (LB) at late maturation stages in brains from idiopathic PD and DLB patients and in LRP10 variant carriers. In conclusion, high LRP10 expression in non-neuronal cells and undetectable levels in neurons of control subjects indicate that LRP10-mediated pathogenicity is initiated via cell non-autonomous mechanisms, potentially involving the interaction of LRP10 with SORL1 in vesicle trafficking pathways. Together with the specific pattern of LRP10 incorporation into mature LBs, these data support an important mechanistic role for disturbed vesicle trafficking and loss of LRP10 function in neurodegenerative diseases
Tevatron Run II combination of the effective leptonic electroweak mixing angle
Drell-Yan lepton pairs produced in the process pp[over ¯]→ℓ⁺ℓ⁻+X through an intermediate γ*/Z boson have an asymmetry in their angular distribution related to the spontaneous symmetry breaking of the electroweak force and the associated mixing of its neutral gauge bosons. The CDF and D0 experiments have measured the effective-leptonic electroweak mixing parameter sin²θ[subscript eff][superscript lept] using electron and muon pairs selected from the full Tevatron proton-antiproton data sets collected in 2001-2011, corresponding to 9–10 fb⁻¹ of integrated luminosity. The combination of these measurements yields the most precise result from hadron colliders, sin²θ[subscript eff][superscript lept] = 0.23148±0.00033. This result is consistent with, and approaches in precision, the best measurements from electron-positron colliders. The standard model inference of the on-shell electroweak mixing parameter sin²θ[subscript W], or equivalently the W-boson mass M[subscript W], using the zfitter software package yields sin²θ[subscript W] = 0.22324±0.00033 or equivalently, M[subscript W] = 80.367±0.017 GeV/c²
Tevatron Combination of Single-Top-Quark Cross Sections and Determination of the Magnitude of the Cabibbo-Kobayashi-Maskawa Matrix Element Vtb
We present the final combination of CDF and D0 measurements of cross sections for single-top-quark production in proton-antiproton collisions at a center-of-mass energy of 1.96 TeV. The data correspond to total integrated luminosities of up to 9.7??fb-1 per experiment. The t-channel cross section is measured to be st=2.25+0.29-0.31??pb. We also present the combinations of the two-dimensional measurements of the s- vs t-channel cross section. In addition, we give the combination of the s+t channel cross section measurement resulting in ss+t=3.30+0.52-0.40??pb, without assuming the standard model value for the ratio ss/st. The resulting value of the magnitude of the top-to-bottom quark coupling is |Vtb|=1.02+0.06-0.05, corresponding to |Vtb|>0.92 at the 95% C.L
Search for resonant WZ production in the fully leptonic final state in proton–proton collisions at √s=13 TeV with the ATLAS detector
Measurement of exclusive pion pair production in proton–proton collisions at √s=7 TeV with the ATLAS detector
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