856 research outputs found

    A structure in the early Universe at z 1.3 that exceeds the homogeneity scale of the R-W concordance cosmology

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    A Large Quasar Group (LQG) of particularly large size and high membership has been identified in the DR7QSO catalogue of the Sloan Digital Sky Survey. It has characteristic size (volume^1/3) ~ 500 Mpc (proper size, present epoch), longest dimension ~ 1240 Mpc, membership of 73 quasars, and mean redshift = 1.27. In terms of both size and membership it is the most extreme LQG found in the DR7QSO catalogue for the redshift range 1.0 = 1.28, which is itself one of the more extreme examples. Their boundaries approach to within ~ 2 deg (~ 140 Mpc projected). This new, huge LQG appears to be the largest structure currently known in the early universe. Its size suggests incompatibility with the Yadav et al. scale of homogeneity for the concordance cosmology, and thus challenges the assumption of the cosmological principle

    Searching High Redshift Large-Scale Structures: Photometry of Four Fields Around Quasar Pairs at z~1

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    We have studied the photometric properties of four fields around the high-redshift quasar pairs QP1310+0007, QP1355-0032, QP0110-0219, and QP0114-3140 at z ~ 1 with the aim of identifying large-scale structures- galaxy clusters or groups- around them. This sample was observed with GMOS in Gemini North and South telescopes in the g', r', i', and z' bands, and our photometry is complete to a limiting magnitude of i' ~ 24 mag (corresponding to ~ M*_i' + 2 at the redshift of the pairs). Our analysis reveals that QP0110-0219 shows very strong and QP1310+0007 and QP1355-0032 show some evidence for the presence of rich galaxy clusters in direct vicinity of the pairs. On the other hand, QP0114-3140 could be an isolated pair in a poor environment. This work suggest that z ~ 1 quasar pairs are excellent tracers of high density environments and this same technique may be useful to find clusters at higher redshifts.Comment: 29 pages, 7 figures, ApJ accepted. Added one figure and 3 references. Some paragraphs was rewritten in sections 1, 3, 5, and 6, as suggested by refere

    Discovery of Two New Faint Cataclysmic Variables

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    We report on the discovery of two new faint cataclysmic variables. The objects were selected as candidates from two different imaging surveys aimed at the discovery of such faint systems. One survey used color and variability while the other used color and Hα_\alpha emission as selection criteria. We present our spectra of the two new variables and discuss their properties. A discussion of the implication of these discoveries on the space density of faint cataclysmic variables is presented.Comment: 4 pages, 4 figures. Accepted to A&A letter

    Sarilumab for Previously-Treated Moderate or Severe Rheumatoid Arthritis: An Evidence Review Group Perspective of a NICE Single Technology Appraisal

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    As part of its single technology appraisal (STA) process, the National Institute for Health and Care Excellence (NICE) invited the manufacturer (Sanofi Genzyme) of sarilumab (SAR; Kevzara®) to submit evidence of its clinical effectiveness and cost-effectiveness for previously treated moderate or severe rheumatoid arthritis (RA). The School of Health and Related Research Technology Appraisal Group at the University of Sheffield was commissioned to act as the independent Evidence Review Group (ERG). The ERG produced a detailed review of the evidence for the clinical effectiveness and cost-effectiveness of the technology, based upon the company's submission to NICE. The clinical effectiveness evidence in the company's submission for SAR was based predominantly on five randomised controlled trials comparing the efficacy of SAR against adalimumab, tocilizumab or placebo. The clinical effectiveness review identified no head-to-head evidence on the efficacy of SAR against all the comparators within the scope. Therefore, the company performed three network meta-analyses (NMAs) in two different populations: two in patients who had had an inadequate response to conventional disease-modifying antirheumatic drugs (cDMARDs) (one for combination therapies and one for monotherapies) and the other one in patients who had had an inadequate response to tumour necrosis factor inhibitors (TNFis). The company's NMAs concluded that SAR in combination with cDMARDs or as monotherapy has a statistically superior efficacy to cDMARDs and a comparable efficacy to most biologic disease-modifying antirheumatic drugs (bDMARDs) in both populations. The company submitted a Markov model that assessed the cost-effectiveness of SAR from the perspective of the National Health Service (NHS) and Personal Social Services in seven different populations: (1) patients with severe RA who have had an inadequate response to cDMARDs (cDMARD-IR); (2) cDMARD-IR patients with severe RA for whom methotrexate (MTX) is contraindicated or not tolerated; (3) patients with severe RA who have had an inadequate response to a TNFi (TNFi-IR); (4) TNFi-IR patients with severe RA for whom rituximab (RTX) is not an option; (5) TNFi-IR patients with severe RA for whom MTX is contraindicated or not tolerated; (6) TNFi-IR patients after RTX; and (7) cDMARD-IR patients with moderate RA whose 28-joint Disease Activity Score (DAS28) is between 4.0 and 5.1. The company's economic evaluation resulted in incremental cost-effectiveness ratios (ICERs) lower than £20,000 per quality-adjusted life year (QALY) gained for SAR in combination with MTX or as monotherapy versus its comparators when the comparators were less effective, and it resulted in cost savings higher than £60,000 per QALY lost when SAR was less effective, except in TNFi-IR patients who are RTX eligible (where the ICER for SAR + MTX compared with RTX + MTX was £130,691 per QALY gained) and in patients with moderate RA and a DAS28 of > 4.0 (where the ICER of SAR + MTX compared with MTX was £38,254 per QALY gained). Following a critique of the model, the ERG undertook exploratory analyses after applying two changes to the company's model: (1) use of a latent class approach to model Health Assessment Questionnaire Disability Index (HAQ-DI) progression for patients on cDMARDs; and (2) amendment of the company's modelling of patient progression from moderate to severe RA. The ICERs estimated by the ERG's exploratory analyses for SAR + MTX increased to £171,466 per QALY gained when compared with RTX + MTX in TNFi-IR patients who are RTX eligible, and to £63,438 per QALY gained when compared with MTX in patients with moderate RA and a DAS28 of > 4.0. The Appraisal Committee concluded that SAR in combination with MTX or as monotherapy is a cost-effective use of NHS resources in the considered populations, except in TNFi-IR patients who are RTX eligible and in patients with moderate RA and a DAS28 of > 4.0

    Talking South African fathers: a critical examination of men’s constructions and experiences of fatherhood and fatherlessness

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    The absence of biological fathers in South Africa has been constructed as a problem for children of both sexes but more so for boy-children. Arguably the dominant discourse in this respect has demonized non-nuclear, female-headed households. Fathers are constructed as either absent or ‘bad’. Thus it has become important to explore more closely how male care-givers have been experienced by groups of men in South Africa. This article examines discourses of fatherhood and fatherlessness by drawing on qualitative interviews with a group of 29 men who speak about their reported experiences and understandings of being fathered or growing up without biological fathers. Two major and intertwined subjugated discourses about adult men’s experiences of being fathered that counter- balance the prevailing discourses about meaning of fatherhood and fatherlessness became evident, namely, ‘being always there’ and ‘talking fatherhood’. The importance of the experience of fatherhood as ‘being there’, which relates to a quality of time and relationship between child and father rather than physical time together, is illustrated. It is not only biological fathers who can ‘be there’ for their sons but also social fathers, other significant male role models and father figures who step in at different times in participants’ lives when biological fathers are unavailable for whatever reason. Second, many positive experiences of fathers or father figures that resist a traditional role of authority and control and subscribe to more nurturant and non-violent forms of care, represented as ‘talking’ fathers, are underlined. If we are to better understand the impact of colonial and apartheid history and its legacy on family life in contemporary society, there is a need for more historically and contextually informed studies on the meaning of fatherhood and fatherlessness.Web of Scienc

    Hookworm Infection and Environmental Factors in Mbeya Region, Tanzania: A Cross-sectional, Population-based study.

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    Hookworm disease is one of the most common infections and cause of a high disease burden in the tropics and subtropics. Remotely sensed ecological data and model-based geostatistics have been used recently to identify areas in need for hookworm control. Cross-sectional interview data and stool samples from 6,375 participants from nine different sites in Mbeya region, south-western Tanzania, were collected as part of a cohort study. Hookworm infection was assessed by microscopy of duplicate Kato-Katz thick smears from one stool sample from each participant. A geographic information system was used to obtain remotely sensed environmental data such as land surface temperature (LST), vegetation cover, rainfall, and elevation, and combine them with hookworm infection data and with socio-demographic and behavioral data. Uni- and multivariable logistic regression was performed on sites separately and on the pooled dataset. Univariable analyses yielded significant associations for all ecological variables. Five ecological variables stayed significant in the final multivariable model: population density (odds ratio (OR) = 0.68; 95% confidence interval (CI) = 0.63-0.73), mean annual vegetation density (OR = 0.11; 95% CI = 0.06-0.18), mean annual LST during the day (OR = 0.81; 95% CI = 0.75-0.88), mean annual LST during the night (OR = 1.54; 95% CI = 1.44-1.64), and latrine coverage in household surroundings (OR = 1.02; 95% CI = 1.01-1.04). Interaction terms revealed substantial differences in associations of hookworm infection with population density, mean annual enhanced vegetation index, and latrine coverage between the two sites with the highest prevalence of infection. This study supports previous findings that remotely sensed data such as vegetation indices, LST, and elevation are strongly associated with hookworm prevalence. However, the results indicate that the influence of environmental conditions can differ substantially within a relatively small geographic area. The use of large-scale associations as a predictive tool on smaller scales is therefore problematic and should be handled with care

    The Double Infared Source Toward the Soft Gamma-Ray Repeater SGR 1900+14

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    We report the results of an extensive set of optical and near-infrared photometry and spectroscopy of the double infrared source reported by Hartmann et al. (1995) as a potential counterpart for the Galatic soft gamma-ray repeater SGR 1900 + 14. These objects are found to be variable but otherwise normal M5 supergiant stars at a distance of ~ 12-15 kpc and extinguised by Av ~ 19.2 mag, primarily by the general interstellar medium. We argue that the supergiants are likely gravitationally bround. These stars are positionally coincident with both quiescent X-ray and IRAS sources, suggestive of a yet-undetected third component to the system which may be responsible for the SGR
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