2,574 research outputs found
Distributional Modes for Scalar Field Quantization
We propose a mode-sum formalism for the quantization of the scalar field
based on distributional modes, which are naturally associated with a slight
modification of the standard plane-wave modes. We show that this formalism
leads to the standard Rindler temperature result, and that these modes can be
canonically defined on any Cauchy surface.Comment: 15 pages, RevTe
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Improvements in the South African HIV care cascade: findings on 90-90-90 targets from successive population-representative surveys in North West Province.
IntroductionTo achieve epidemic control of HIV by 2030, countries aim to meet 90-90-90 targets to increase knowledge of HIV-positive status, initiation of antiretroviral therapy (ART) and viral suppression by 2020. We assessed the progress towards these targets from 2014 to 2016 in South Africa as expanded treatment policies were introduced using population-representative surveys.MethodsData were collected in January to March 2014 and August to November 2016 in Dr. Ruth Segomotsi Mompati District, North West Province. Each multi-stage cluster sample included 46 enumeration areas (EA), a target of 36 dwelling units (DU) per EA, and a single resident aged 18 to 49 per DU. Data collection included behavioural surveys, rapid HIV antibody testing and dried blood spot collection. We used weighted general linear regression to evaluate differences in the HIV care continuum over time.ResultsOverall, 1044 and 971 participants enrolled in 2014 and 2016 respectively with approximately 77% undergoing HIV testing. Despite increases in reported testing, known status among people living with HIV (PLHIV) remained similar at 68.7% (95% Confidence Interval (CI) = 60.9-75.6) in 2014 and 72.8% (95% CI = 63.6-80.4) in 2016. Men were consistently less likely than women to know their status. Among those with known status, PLHIV on ART increased significantly from 80.9% (95% CI = 71.9-87.4) to 91.5% (95% CI = 84.4-95.5). Viral suppression (<5000 copies/mL using DBS) among those on ART increased significantly from 55.0% (95% CI = 39.6-70.4) in 2014 to 81.4% (95% CI = 72.0-90.8) in 2016. Among all PLHIV an estimated 72.0% (95% CI = 63.8-80.1) of women and 45.8% (95% CI = 27.0-64.7) of men achieved viral suppression by 2016.ConclusionsOver a period during which fixed-dose combination was introduced, ART eligibility expanded, and efforts to streamline treatment were implemented, major improvements in the second and third 90-90-90 targets were achieved. Achieving the first 90 target will require targeted and improved testing models for men
Abscission couples cell division to embryonic stem cell fate
Cell fate transitions are key to development and homeostasis. It is thus essential to understand the cellular mechanisms controlling fate transitions. Cell division has been implicated in fate decisions in many stem cell types, including neuronal and epithelial progenitors. In other stem cells, such as embryonic stem (ES) cells, the role of division remains unclear. Here, we show that exit from naive pluripotency in mouse ES cells generally occurs after a division. We further show that exit timing is strongly correlated between sister cells, which remain connected by cytoplasmic bridges long after division, and that bridge abscission progressively accelerates as cells exit naive pluripotency. Finally, interfering with abscission impairs naive pluripotency exit, and artificially inducing abscission accelerates it. Altogether, our data indicate that a switch in the division machinery leading to faster abscission regulates pluripotency exit. Our study identifies abscission as a key cellular process coupling cell division to fate transitions
Evaluating a scale of excessive mind wandering among males and females with and without attention-deficit/hyperactivity disorder from a population sample
Recent studies highlight the role of excessive mind wandering in attention-deficit/hyperactivity disorder (ADHD) and its association with impairment. We believe assessing mind wandering could be especially relevant to individuals, including many females, who present with less externalising manifestations of ADHD. Using a new measure based on ADHD patient reports, the Mind Excessively Wandering Scale (MEWS), we previously found adults with ADHD had elevated levels of mind wandering that contributed to impairment independently of core ADHD symptoms. Using data from an online general population survey, the current study assessed the factor-structure, reliability, validity and measurement invariance of the MEWS. We also investigated sex differences in mind wandering, as well as ADHD symptoms, impairment and wellbeing in those with and without ADHD. The MEWS had a unidimensional structure, was invariant across sex, age and ADHD status, and accounted for unique variance in impairment and wellbeing beyond core ADHD symptoms. Among those with ADHD, we found no evidence for sex differences in mind wandering and among those without ADHD males had higher scores. We also found similar levels of hyperactivity/impulsivity, emotional lability, and impairment in males and females with ADHD, but males reported greater inattention and lower wellbeing. Results suggest the MEWS is a reliable and valid instrument measuring the same construct across sex, age and ADHD status, which could aid diagnosis and monitoring of outcomes
Tidal Response of Mars Constrained From Laboratory-Based Viscoelastic Dissipation Models and Geophysical Data
We employ laboratory-based grain-size- and temperature-sensitive rheological models to
16 describe the viscoelastic behavior of terrestrial bodies with focus on Mars. Shear modulus
17 reduction and attenuation related to viscoelastic relaxation occur as a result of diffusion-
18 and dislocation-related creep and grain-boundary processes. We consider five rheological
19 models, including extended Burgers, Andrade, Sundberg-Cooper, a power-law approxima-
20 tion, and Maxwell, and determine Martian tidal response. However, the question of which
21 model provides the most appropriate description of dissipation in planetary bodies, re-
22 mains an open issue. To examine this, crust and mantle models (density and elasticity) are
23 computed self-consistently through phase equilibrium calculations as a function of pres-
24 sure, temperature, and bulk composition, whereas core properties are based on an Fe-FeS
25 parameterisation. We assess the compatibility of the viscoelastic models by inverting the
26 available geophysical data for Mars (tidal response and mean density and moment of in-
27 ertia) for temperature, elastic, and attenuation structure. Our results show that although
28 all viscoelastic models are consistent with data, their predictions for the tidal response at
29 other periods and harmonic degrees are distinct. The results also show that Maxwell is
30 only capable of fitting data for unrealistically low viscosities. Our approach can be used
31 quantitatively to distinguish between the viscoelastic models from seismic and/or tidal ob-
32 servations that will allow for improved constraints on interior structure (e.g., with InSight).
33 Finally, the methodology presented here is generally formulated and applicable to other so-
34 lar and extra-solar system bodies where the study of tidal dissipation presents an important
35 means for determining interior structure
Uterine Mast Cells and Immunoglobulin-E Antibody Responses During Clearance of \u3ci\u3eTritrichomonas foetus\u3c/i\u3e
We showed earlier that Tritrichomonas foetusâspecific bovine immunoglobulin (Ig)G1 and IgA antibodies in uterine and vaginal secretions are correlated with clearance of this sexually transmitted infection. Eosinophils have been noted in previous studies of bovine trichomoniasis but the role of mast cells and IgE responses have not been reported. The hypothesis that IgE and mast cell degranulation play a role in clearance was tested in 25 virgin heifers inseminated experimentally and infected intravaginally with T. foetus strain D1 at estrus and cultured weekly. Groups were euthanatized at 3, 6, 9, or 12 weeks, when tissues were fixed and secretions were collected for culture and antibody analysis. Immunohistochemistry using a monoclonal antibody to a soluble lipophosphoglycan (LPG)âcontaining surface antigen (TF1.17) demonstrated antigen uptake by uterine epithelial cells. Lymphoid nodules were detected below antigen-positive epithelium. Little IgG2 antibody was detected but IgG1, IgA, IgM, and IgE T. foetusâspecific antibodies increased in uterine secretions at weeks 6 and 9 after infection. This was inversely proportional to subepithelial mast cells numbers and most animals cleared the infection by the sampling time after the lowest mast cell count. Furthermore, soluble antigen was found in uterine epithelium above inductive sites (lymphoid nodules). Cross-linking of IgE on mast cells by antigen and perhaps LPG triggering appears to have resulted in degranulation. Released cytokines may account for production of predominantly Th2 (IgG1 and IgE) and IgA antibody responses, which are related to clearance of the infection
Constraints on Models for the Higgs Boson with Exotic Spin and Parity in VH â VbÂŻb Final States
This is the published version. Copyright © 2014 American Physical SocietyWe present constraints on models containing non-standard-model values for the spin J and parity P of the Higgs boson H in up to 9.7ââfbâ1 of ppÂŻ collisions at sâ=1.96ââTeV collected with the D0 detector at the Fermilab Tevatron Collider. These are the first studies of Higgs boson JP with fermions in the final state. In the ZHâââbbÂŻ, WHââÎœbbÂŻ, and ZHâΜΜbbÂŻ final states, we compare the standard model (SM) Higgs boson prediction, JP=0+, with two alternative hypotheses, JP=0â and JP=2+. We use a likelihood ratio to quantify the degree to which our data are incompatible with non-SM JP predictions for a range of possible production rates. Assuming that the production rate in the signal models considered is equal to the SM prediction, we reject the JP=0â and JP=2+ hypotheses at the 97.6% CL and at the 99.0% CL, respectively. The expected exclusion sensitivity for a JP=0â (JP=2+) state is at the 99.86% (99.94%) CL. Under the hypothesis that our data are the result of a combination of the SM-like Higgs boson and either a JP=0â or a JP=2+ signal, we exclude a JP=0â fraction above 0.80 and a JP=2+ fraction above 0.67 at the 95% CL. The expected exclusion covers JP=0â (JP=2+) fractions above 0.54 (0.47)
Measurement of the B0s Lifetime in the Flavor-Specific Decay Channel B0sâDâsÎŒ+ÎœX
This is the published version. Copyright 2015 American Physical SocietyWe present an updated measurement of the B0s lifetime using the semileptonic decays B0sâDâsÎŒ+ÎœX, with DâsâÏÏâ and ÏâK+Kâ (and the charge conjugate process). This measurement uses the full Tevatron Run II sample of proton-antiproton collisions at sâ=1.96ââTeV, comprising an integrated luminosity of 10.4ââfbâ1. We find a flavor-specific lifetime Ïfs(B0s)=1.479±0.010(stat)±0.021(syst)ââps. This technique is also used to determine the B0 lifetime using the analogous B0âDâÎŒ+ÎœX decay with DââÏÏâ and ÏâK+Kâ, yielding Ï(B0)=1.534±0.019(stat)±0.021(syst)ââps. Both measurements are consistent with the current world averages, and the B0s lifetime measurement is one of the most precise to date. Taking advantage of the cancellation of systematic uncertainties, we determine the lifetime ratio Ïfs(B0s)/Ï(B0)=0.964±0.013(stat)±0.007(syst)
Renewing Criminalized and Hegemonic Cultural Landscapes
The Mafia's long historical pedigree in Mezzogiorno, Southern Italy, has empowered the Mafioso as a notorious, uncontested, and hegemonic figure. The counter-cultural resistance against the mafiosi culture began to be institutionalized in the early 1990s. Today, Libera Terra is the largest civil society organization in the country that uses the lands confiscated from the Mafia as a space of cultural repertoire to realize its ideals. Deploying labor force through volunteer participation, producing biological fruits and vegetables, and providing information to the students on the fields are the principal cultural practices of this struggle. The confiscated lands make the Italian experience of anti-Mafia resistance a unique example by connecting the land with the ideals of cultural change. The sociocultural resistance of Libera Terra conveys a political message through these practices and utters that the Mafia is not invincible. This study draws the complex panorama of the Mafia and anti-Mafia movement that uses the âconfiscated landsâ as cultural and public spaces for resistance and socio-cultural change. In doing so, this article sheds new light on the relationship between rural criminology and crime prevention policies in Southern Italy by demonstrating how community development practice of Libera Terra changes the meaning of landscape through iconographic symbolism and ethnographic performance
Homothetic perfect fluid space-times
A brief summary of results on homotheties in General Relativity is given,
including general information about space-times admitting an r-parameter group
of homothetic transformations for r>2, as well as some specific results on
perfect fluids. Attention is then focussed on inhomogeneous models, in
particular on those with a homothetic group (acting multiply
transitively) and . A classification of all possible Lie algebra
structures along with (local) coordinate expressions for the metric and
homothetic vectors is then provided (irrespectively of the matter content), and
some new perfect fluid solutions are given and briefly discussed.Comment: 27 pages, Latex file, Submitted to Class. Quantum Gra
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