558 research outputs found

    Multiwavelength Observations of the Second Largest Known FR II Radio Galaxy, NVSS 2146+82

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    We present multi-frequency VLA, multicolor CCD imaging, optical spectroscopy, and ROSAT HRI observations of the giant FR II radio galaxy NVSS 2146+82. This galaxy, which was discovered by the NRAO VLA Sky Survey (NVSS), has an angular extent of nearly 20' from lobe to lobe. The radio structure is normal for an FR II source except for its large size and regions in the lobes with unusually flat radio spectra. Our spectroscopy indicates that the optical counterpart of the radio core is at a redshift of z=0.145, so the linear size of the radio structure is ~4 h_50^-1 Mpc. This object is therefore the second largest FR II known (3C 236 is ~6 h_50^-1 Mpc). Optical imaging of the field surrounding the host galaxy reveals an excess number of candidate galaxy cluster members above the number typically found in the field surrounding a giant radio galaxy. WIYN HYDRA spectra of a sample of the candidate cluster members reveal that six share the same redshift as NVSS 2146+82, indicating the presence of at least a ``rich group'' containing the FR II host galaxy. ROSAT HRI observations of NVSS 2146+82 place upper limits on the X-ray flux of 1.33 x 10^-13 ergs cm^-2 s^-1 for any hot IGM and 3.52 x 10^-14 ergs cm^-2 s^-1 for an X-ray AGN, thereby limiting any X-ray emission at the distance of the radio galaxy to that typical of a poor group or weak AGN. Several other giant radio galaxies have been found in regions with overdensities of nearby galaxies, and a separate study has shown that groups containing FR IIs are underluminous in X-rays compared to groups without radio sources. We speculate that the presence of the host galaxy in an optically rich group of galaxies that is underluminous in X-rays may be related to the giant radio galaxy phenomenon.Comment: 46 pages, 15 figures, AASTeX aaspp4 style, accepted for publication in A

    Accommodating 'others'?: housing dispersed, forced migrants in the UK

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    Utilising insights from a qualitative study in the city of Leeds (UK), this paper considers issues related to the housing of dispersed forced migrants. The term 'dispersed forced migrants' is used here as a general label to include four groups of international migrants (i.e. refugees, asylum seekers, those with humanitarian protection status and failed asylum seekers) who have previously been dispersed, on a no choice basis, to a variety of locations across the UK under the requirements of the Immigration and Asylum Act (1999). The tiering of housing entitlement that exists within the generic population of dispersed forced migrants (a consequence of the particular socio-legal status assigned to individuals), and its role in rendering migrants susceptible to homelessness is outlined. The adequacy/standard of accommodation made available to forced migrants is also discussed. It is concluded that current arrangements fail to meet the basic housing needs of many forced migrants. Any future improvement in this situation will require a significant shift in government policy

    Cognitive testing of physical activity and acculturation questions in recent and long-term Latino immigrants

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    <p>Abstract</p> <p>Background</p> <p>We ascertained the degree to which language (English versus Spanish), and residence time in the US influence responses to survey questions concerning two topics: self-reported acculturation status, and recent physical activity (PA). This topic is likely to be of general interest because of growing numbers of immigrants in countries worldwide.</p> <p>Methods</p> <p>We carried out qualitative (cognitive) interviews of survey items on acculturation and physical activity on 27 Latino subjects from three groups: (a) In Spanish, of those of low residence time (less than five years living in the U.S.) (n = 9); (b) In Spanish, of those of high residence time (15 or more years in the U.S) (n = 9); and (c) in English, of those of high residence time (n = 9).</p> <p>Results</p> <p>There were very few language translation problems; general question design defects and socio-cultural challenges to survey responses were more common. Problems were found for both acculturation and PA questions, with distinct problem types for the two question areas. Residence time/language group was weakly associated with overall frequency of problems observed: low residence time/Spanish (86%), high residence time/Spanish (67%), and English speaking groups (62%).</p> <p>Conclusions</p> <p>Standardized survey questions related to acculturation and physical activity present somewhat different cognitive challenges. For PA related questions, problems with such questions were similar regardless of subject residence time or language preference. For acculturation related questions, residence time/language or education level influenced responses to such questions. These observations should help in the interpretation of survey results for culturally diverse populations.</p

    Evidence for Thalamic Involvement in the Thermal Grill Illusion: An fMRI Study

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    Perceptual illusions play an important role in untangling neural mechanisms underlying conscious phenomena. The thermal grill illusion (TGI) has been suggested as a promising model for exploring percepts involved in neuropathic pain, such as cold-allodynia (pain arising from contact with innocuous cold). The TGI is an unpleasant/painful sensation from touching juxtapositioned bars of cold and warm innocuous temperatures.To develop an MRI-compatible TGI-unit and explore the supraspinal correlates of the illusion, using fMRI, in a group of healthy volunteers.We constructed a TGI-thermode allowing the rapid presentation of warm(41°C), cold(18°C) and interleaved(41°C+18°C = TGI) temperatures in an fMRI-environment. Twenty volunteers were tested. The affective-motivational (“unpleasantness”) and sensory-disciminatory (“pain-intensity”) dimensions of each respective stimulus were rated. Functional images were analyzed at a corrected α-level <0.05.The TGI was rated as significantly more unpleasant and painful than stimulation with each of its constituent temperatures. Also, the TGI was rated as significantly more unpleasant than painful. Thermal stimulation versus neutral baseline revealed bilateral activations of the anterior insulae and fronto-parietal regions. Unlike its constituent temperatures the TGI displayed a strong activation of the right (contralateral) thalamus. Exploratory contrasts at a slightly more liberal threshold-level also revealed a TGI-activation of the right mid/anterior insula, correlating with ratings of unpleasantness(rho = 0.31).To the best of our knowledge, this is the first fMRI-study of the TGI. The activation of the anterior insula is consistent with this region's putative role in processing of homeostatically relevant feeling-states. Our results constitute the first neurophysiologic evidence of thalamic involvement in the TGI. Similar thalamic activity has previously been observed during evoked cold-allodynia in patients with central neuropathic pain. Our results further the understanding of the supraspinal correlates of the TGI-phenomenon and pave the way for future inquiries into if and how it may relate to neuropathic pain

    Surface Roughness and Effective Stick-Slip Motion

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    The effect of random surface roughness on hydrodynamics of viscous incompressible liquid is discussed. Roughness-driven contributions to hydrodynamic flows, energy dissipation, and friction force are calculated in a wide range of parameters. When the hydrodynamic decay length (the viscous wave penetration depth) is larger than the size of random surface inhomogeneities, it is possible to replace a random rough surface by effective stick-slip boundary conditions on a flat surface with two constants: the stick-slip length and the renormalization of viscosity near the boundary. The stick-slip length and the renormalization coefficient are expressed explicitly via the correlation function of random surface inhomogeneities. The effective stick-slip length is always negative signifying the effective slow-down of the hydrodynamic flows by the rough surface (stick rather than slip motion). A simple hydrodynamic model is presented as an illustration of these general hydrodynamic results. The effective boundary parameters are analyzed numerically for Gaussian, power-law and exponentially decaying correlators with various indices. The maximum on the frequency dependence of the dissipation allows one to extract the correlation radius (characteristic size) of the surface inhomogeneities directly from, for example, experiments with torsional quartz oscillators.Comment: RevTeX4, 14 pages, 3 figure

    Loop Quantum Cosmology: A Status Report

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    The goal of this article is to provide an overview of the current state of the art in loop quantum cosmology for three sets of audiences: young researchers interested in entering this area; the quantum gravity community in general; and, cosmologists who wish to apply loop quantum cosmology to probe modifications in the standard paradigm of the early universe. An effort has been made to streamline the material so that, as described at the end of section I, each of these communities can read only the sections they are most interested in, without a loss of continuity.Comment: 138 pages, 15 figures. Invited Topical Review, To appear in Classical and Quantum Gravity. Typos corrected, clarifications and references adde

    Gravitational Waves From Known Pulsars: Results From The Initial Detector Era

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    We present the results of searches for gravitational waves from a large selection of pulsars using data from the most recent science runs (S6, VSR2 and VSR4) of the initial generation of interferometric gravitational wave detectors LIGO (Laser Interferometric Gravitational-wave Observatory) and Virgo. We do not see evidence for gravitational wave emission from any of the targeted sources but produce upper limits on the emission amplitude. We highlight the results from seven young pulsars with large spin-down luminosities. We reach within a factor of five of the canonical spin-down limit for all seven of these, whilst for the Crab and Vela pulsars we further surpass their spin-down limits. We present new or updated limits for 172 other pulsars (including both young and millisecond pulsars). Now that the detectors are undergoing major upgrades, and, for completeness, we bring together all of the most up-to-date results from all pulsars searched for during the operations of the first-generation LIGO, Virgo and GEO600 detectors. This gives a total of 195 pulsars including the most recent results described in this paper.United States National Science FoundationScience and Technology Facilities Council of the United KingdomMax-Planck-SocietyState of Niedersachsen/GermanyAustralian Research CouncilInternational Science Linkages program of the Commonwealth of AustraliaCouncil of Scientific and Industrial Research of IndiaIstituto Nazionale di Fisica Nucleare of ItalySpanish Ministerio de Economia y CompetitividadConselleria d'Economia Hisenda i Innovacio of the Govern de les Illes BalearsNetherlands Organisation for Scientific ResearchPolish Ministry of Science and Higher EducationFOCUS Programme of Foundation for Polish ScienceRoyal SocietyScottish Funding CouncilScottish Universities Physics AllianceNational Aeronautics and Space AdministrationOTKA of HungaryLyon Institute of Origins (LIO)National Research Foundation of KoreaIndustry CanadaProvince of Ontario through the Ministry of Economic Development and InnovationNational Science and Engineering Research Council CanadaCarnegie TrustLeverhulme TrustDavid and Lucile Packard FoundationResearch CorporationAlfred P. Sloan FoundationAstronom

    A whole genome association study of neuroticism using DNA pooling.

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    We describe a multistage approach to identify single nucleotide polymorphisms (SNPs) associated with neuroticism, a personality trait that shares genetic determinants with major depression and anxiety disorders. Whole genome association with 452 574 SNPs was performed on DNA pools from approximately 2000 individuals selected on extremes of neuroticism scores from a cohort of 88 142 people from southwest England. The most significant SNPs were then genotyped on independent samples to replicate findings. We were able to replicate association of one SNP within the PDE4D gene in a second sample collected by our laboratory and in a family-based test in an independent sample; however, the SNP was not significantly associated with neuroticism in two other independent samples. We also observed an enrichment of low P-values in known regions of copy number variations. Simulation indicates that our study had approximately 80% power to identify neuroticism loci in the genome with odds ratio (OR)&gt;2, and approximately 50% power to identify small effects (OR=1.5). Since we failed to find any loci accounting for more than 1% of the variance, the heritability of neuroticism probably arises from many loci each explaining much less than 1%. Our findings argue the need for much larger samples than anticipated in genetic association studies and that the biological basis of emotional disorders is extremely complex

    Comparative effectiveness of antiepileptic drugs in juvenile myoclonic epilepsy

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    Objective: To study the effectiveness and tolerability of antiepileptic drugs (AEDs) commonly used in juvenile myoclonic epilepsy (JME). Methods: People with JME were identified from a large database of individuals with epilepsy, which includes detailed retrospective information on AED use. We assessed secular changes in AED use and calculated rates of response (12-month seizure freedom) and adverse drug reactions (ADRs) for the five most common AEDs. Retention was modeled with a Cox proportional hazards model. We compared valproate use between males and females. Results: We included 305 people with 688 AED trials of valproate, lamotrigine, levetiracetam, carbamazepine, and topiramate. Valproate and carbamazepine were most often prescribed as the first AED. The response rate to valproate was highest among the five AEDs (42.7%), and significantly higher than response rates for lamotrigine, carbamazepine, and topiramate; the difference to the response rate to levetiracetam (37.1%) was not significant. The rates of ADRs were highest for topiramate (45.5%) and valproate (37.5%). Commonest ADRs included weight change, lethargy, and tremor. In the Cox proportional hazards model, later start year (1.10 [1.08-1.13], P&nbsp;&lt;&nbsp;0.001) and female sex (1.41 [1.07-1.85], P&nbsp;=&nbsp;0.02) were associated with shorter trial duration. Valproate was associated with the longest treatment duration; trials with carbamazepine and topiramate were significantly shorter (HR [CI]: 3.29 [2.15-5.02], P&nbsp;&lt;&nbsp;0.001 and 1.93 [1.31-2.86], P&nbsp;&lt;&nbsp;0.001). The relative frequency of valproate trials shows a decreasing trend since 2003 while there is an increasing trend for levetiracetam. Fewer females than males received valproate (76.2% vs 92.6%, P&nbsp;=&nbsp;0.001). Significance: In people with JME, valproate is an effective AED; levetiracetam emerged as an alternative. Valproate is now contraindicated in women of childbearing potential without special precautions. With appropriate selection and safeguards in place, valproate should remain available as a therapy, including as an alternative for women of childbearing potential whose seizures are resistant to other treatments

    Mitochondrial sulfide promotes life span and health span through distinct mechanisms in developing versus adult treated Caenorhabditis elegans

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    Living longer without simultaneously extending years spent in good health ("health span") is an increasing societal burden, demanding new therapeutic strategies. Hydrogen sulfide (H S) can correct disease-related mitochondrial metabolic deficiencies, and supraphysiological H S concentrations can pro health span. However, the efficacy and mechanisms of mitochondrion-targeted sulfide delivery molecules (mtH S) administered across the adult life course are unknown. Using a aging model, we compared untargeted H S (NaGYY4137, 100 ”M and 100 nM) and mtH S (AP39, 100 nM) donor effects on life span, neuromuscular health span, and mitochondrial integrity. H S donors were administered from birth or in young/middle-aged animals (day 0, 2, or 4 postadulthood). RNAi pharmacogenetic interventions and transcriptomics/network analysis explored molecular events governing mtH S donor-mediated health span. Developmentally administered mtH S (100 nM) improved life/health span vs. equivalent untargeted H S doses. mtH S preserved aging mitochondrial structure, content (citrate synthase activity) and neuromuscular strength. Knockdown of H S metabolism enzymes and FoxO/ prevented the positive health span effects of mtH S, whereas DCAF11/ - Nrf2/ oxidative stress protection pathways were dispensable. Health span, but not life span, increased with all adult-onset mtH S treatments. Adult mtH S treatment also rejuvenated aging transcriptomes by minimizing expression declines of mitochondria and cytoskeletal components, and peroxisome metabolism hub components, under mechanistic control by the / transcription factor circuit. H S health span extension likely acts at the mitochondrial level, the mechanisms of which dissociate from life span across adult vs. developmental treatment timings. The small mtH S doses required for health span extension, combined with efficacy in adult animals, suggest mtH S is a potential healthy aging therapeutic
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