1,652 research outputs found

    A Spectroscopic Survey of the Fields of 28 Strong Gravitational Lenses: The Group Catalog

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    With a large, unique spectroscopic survey in the fields of 28 galaxy-scale strong gravitational lenses, we identify groups of galaxies in the 26 adequately-sampled fields. Using a group finding algorithm, we find 210 groups with at least five member galaxies; the median number of members is eight. Our sample spans redshifts of 0.04 zgrp\le z_{grp} \le 0.76 with a median of 0.31, including 174 groups with 0.1<zgrp<0.60.1 < z_{grp} < 0.6. Groups have radial velocity dispersions of 60 σgrp\le \sigma_{grp} \le 1200 km s1^{-1} with a median of 350 km s1^{-1}. We also discover a supergroup in field B0712+472 at z=z = 0.29 consisting of three main groups. We recover groups similar to \sim 85% of those previously reported in these fields within our redshift range of sensitivity and find 187 new groups with at least five members. The properties of our group catalog, specifically 1) the distribution of σgrp\sigma_{grp}, 2) the fraction of all sample galaxies that are group members, and 3) the fraction of groups with significant substructure, are consistent with those for other catalogs. The distribution of group virial masses agrees well with theoretical expectations. Of the lens galaxies, 12 of 26 (46%) (B1422+231, B1600+434, B2114+022, FBQS J0951+2635, HE0435-1223, HST J14113+5211, MG0751+2716, MGJ1654+1346, PG 1115+080, Q ER 0047-2808, RXJ1131-1231, and WFI J2033-4723) are members of groups with at least five galaxies, and one more (B0712+472) belongs to an additional, visually identified group candidate. There are groups not associated with the lens that still are likely to affect the lens model; in six of 25 (24%) fields (excluding the supergroup), there is at least one massive (σgrp\sigma_{grp} \ge 500 km s1^{-1}) group or group candidate projected within 2^{\prime} of the lens.Comment: 87 pages, 8 figures, a version of this was published in Ap

    A Spectroscopic Survey of the Fields of 28 Strong Gravitational Lenses: Implications for H0H_0

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    Strong gravitational lensing provides an independent measurement of the Hubble parameter (H0H_0). One remaining systematic is a bias from the additional mass due to a galaxy group at the lens redshift or along the sightline. We quantify this bias for more than 20 strong lenses that have well-sampled sightline mass distributions, focusing on the convergence κ\kappa and shear γ\gamma. In 23% of these fields, a lens group contributes a \ge1% convergence bias; in 57%, there is a similarly significant line-of-sight group. For the nine time delay lens systems, H0H_0 is overestimated by 112+3^{+3}_{-2}% on average when groups are ignored. In 67% of fields with total κ\kappa \ge 0.01, line-of-sight groups contribute 2×\gtrsim 2\times more convergence than do lens groups, indicating that the lens group is not the only important mass. Lens environment affects the ratio of four (quad) to two (double) image systems; all seven quads have lens groups while only three of 10 doubles do, and the highest convergences due to lens groups are in quads. We calibrate the γ\gamma-κ\kappa relation: log(κtot)=(1.94±0.34)log(γtot)+(1.31±0.49)\log(\kappa_{\rm{tot}}) = (1.94 \pm 0.34) \log(\gamma_{\rm{tot}}) + (1.31 \pm 0.49) with a rms scatter of 0.34 dex. Shear, which, unlike convergence, can be measured directly from lensed images, can be a poor predictor of κ\kappa; for 19% of our fields, κ\kappa is 2γ\gtrsim 2\gamma. Thus, accurate cosmology using strong gravitational lenses requires precise measurement and correction for all significant structures in each lens field.Comment: 34 pages, 11 figures, accepted for publication in Ap

    Opposite environmental and genetic influences on body size in North American Drosophila pseudoobscura

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    BACKGROUND: Populations of a species often differ in key traits. However, it is rarely known whether these differences are associated with genetic variation and evolved differences between populations, or are instead simply a plastic response to environmental differences experienced by the populations. Here we examine the interplay of plasticity and direct genetic control by investigating temperature-size relationships in populations of Drosophila pseudoobscura from North America. We used 27 isolines from three populations and exposed them to four temperature regimes (16°C, 20°C, 23°C, 26°C) to examine environmental, genetic and genotype-by-environment sources of variance in wing size. RESULTS: By far the largest contribution to variation in wing size came from rearing temperature, with the largest flies emerging from the coolest temperatures. However, we also found a genetic signature that was counter to this pattern as flies originating from the northern, cooler population were consistently smaller than conspecifics from more southern, warmer populations when reared under the same laboratory conditions. CONCLUSIONS: We conclude that local selection on body size appears to be acting counter to the environmental effect of temperature. We find no evidence that local adaptation in phenotypic plasticity can explain this result, and suggest indirect selection on traits closely linked with body size, or patterns of chromosome inversion may instead be driving this relationship. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12862-015-0323-3) contains supplementary material, which is available to authorized users

    Generation of human induced pluripotent stem cell-derived cerebral organoids for cellular and molecular characterization

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    Human induced pluripotent stem cell (hiPSC)-derived cerebral organoids (COs) can serve as a

    Exploring the role of pain as an early predictor of category 2 pressure ulcers: a prospective cohort study

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    Objective To explore pressure area related pain as a predictor of category ≥2 pressure ulcer (PU) development. Design Multicentre prospective cohort study. Setting UK hospital and community settings. Participants inclusion Consenting acutely ill patients aged ≥18 years, defined as high risk (Braden bedfast/chairfast AND completely immobile/very limited mobility; pressure area related pain or; category 1 PU). Exclusion Patients too unwell, unable to report pain, 2 or more category ≥2 PUs. Follow-up Twice weekly for 30 days. Primary and secondary outcome measures Development and time to development of one or more category ≥2 PUs. Results Of 3819 screened, 1266 were eligible, 634 patients were recruited, 32 lost to follow-up, providing a 602 analysis population. 152 (25.2%) developed one or more category ≥2 PUs. 464 (77.1%) patients reported pressure area related pain on a healthy, altered or category 1 skin site of whom 130 (28.0%) developed a category ≥2 PU compared with 22 (15.9%) of those without pain. Full stepwise variable selection was used throughout the analyses. (1) Multivariable logistic regression model to assess 9 a priori factors: presence of category 1 PU (OR=3.25, 95% CI (2.17 to 4.86), p<0.0001), alterations to intact skin (OR=1.98, 95% CI (1.30 to 3.00), p=0.0014), pressure area related pain (OR=1.56, 95% CI (0.93 to 2.63), p=0.0931). (2) Multivariable logistic regression model to account for overdispersion: presence of category 1 PU (OR=3.20, 95% CI (2.11 to 4.85), p<0.0001), alterations to intact skin (OR=1.90, 95% CI (1.24 to 2.91), p=0.0032), pressure area related pain (OR=1.85, 95% CI (1.07 to 3.20), p=0.0271), pre-existing category 2 PU (OR=2.09, 95% CI (1.35 to 3.23), p=0.0009), presence of chronic wound (OR=1.66, 95% CI (1.06 to 2.62), p=0.0277), Braden activity (p=0.0476). (3) Accelerated failure time model: presence of category 1 PU (AF=2.32, 95% CI (1.73 to 3.12), p<0.0001), pressure area related pain (AF=2.28, 95% CI (1.59 to 3.27), p<0.0001). (4) 2-level random-intercept logistic regression model: skin status which comprised 2 levels (versus healthy skin); alterations to intact skin (OR=4.65, 95% CI (3.01 to 7.18), p<0.0001), presence of category 1 PU (OR=17.30, 95% CI (11.09 to 27.00), p<0.0001) and pressure area related pain (OR=2.25, 95% CI (1.53 to 3.29), p<0.0001). Conclusions This is the first study to assess pain as a predictor of category ≥2 PU development. In all 4 models, pain emerged as a risk factor associated with an increased probability of category ≥2 PU development

    Computational fluid dynamic analysis of upper airway procedures in equine larynges

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    IntroductionComputational fluid dynamics (CFD) has proven useful in the planning of upper airway surgery in humans, where it is used to anticipate the influence of the surgical procedures on post-operative airflow. This technology has only been reported twice in an equine model, with a limited scope of airflow mechanics situations examined. The reported study sought to widen this application to the variety of procedures used to treat equine recurrent laryngeal neuropathy (RLN). The first objective of this study was to generate a CFD model of an ex-vivo box model of ten different equine larynges replicating RLN and four therapeutic surgeries to compare the calculated impedance between these procedures for each larynx. The second objective was to determine the accuracy between a CFD model and measured airflow characteristics in equine larynges. The last objective was to explore the anatomic distribution of changes in pressure, velocity, and turbulent kinetic energy associated with the disease (RLN) and each surgical procedure performed.MethodsTen equine cadaveric larynges underwent inhalation airflow testing in an instrumented box while undergoing a concurrent computed tomographic (CT) exam. The pressure upstream and downstream (outlet) were measured simultaneously. CT image segmentation was performed to generate stereolithography files, which underwent CFD analysis using the experimentally measured outlet pressure. The ranked procedural order and calculated laryngeal impedance were compared to the experimentally obtained values.Results and discussionThe CFD model agreed with the measured results in predicting the procedure resulting in the lowest post-operative impedance in 9/10 larynges. Numerically, the CFD calculated laryngeal impedance was approximately 0.7 times that of the measured calculation. Low pressure and high velocity were observed around regions of tissue protrusion within the lumen of the larynx. RLN, the corniculectomy and partial arytenoidectomy surgical procedures exhibited low pressure troughs and high velocity peaks compared to the laryngoplasty and combined laryngoplasty/corniculectomy procedures. CFD modeling of the equine larynx reliably calculated the lowest impedance of the different surgical procedures. Future development of the CFD technique to this application may improve numerical accuracy and is recommended prior to consideration for use in patients

    Career Cartography: From Stories to Science and Scholarship

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    PurposeTo present four case scenarios reflecting the process of research career development using career cartography.Organizing ConstructsCareer cartography is a novel approach that enables nurses, from all clinical and academic settings, to actively engage in a process that maximizes their clinical, teaching, research, and policy contributions that can improve patient outcomes and the health of the public.MethodsFour earlyâ career nurse researchers applied the career cartography framework to describe their iterative process of research career development. They report the development process of each of the components of career cartography, including destination statement, career map, and policy statement.ConclusionsDespite diverse research interests and career mapping approaches, common experiences emerged from the four nurse researchers. Common lessons learned throughout the career cartography process include: (a) have a supportive mentorship team, (b) start early and reflect regularly, (c) be brief and to the point, (d) keep it simple and avoid jargon, (e) be open to change, (f) make time, and (g) focus on the overall career destination.Clinical RelevanceThese four case scenarios support the need for nurse researchers to develop their individual career cartography. Regardless of their background, career cartography can help nurse researchers articulate their meaningful contributions to science, policy, and health of the public.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/136693/1/jnu12289.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136693/2/jnu12289_am.pd

    Biosimilar infliximab use in paediatric IBD

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    Background Biosimilar infliximab became available in the UK in 2015. Paediatric experience to date on its use is limited. We prospectively evaluated the safety and efficacy of biosimilar infliximab (Remsima) in two paediatric gastroenterology networks in patients with inflammatory bowel disease. Methods Prospective clinical data were collected from laboratory reports, electronic patient records and case notes of 40 patients starting Remsima for the first time. Disease activity scores together with blood and stool biomarkers were used to assess response. Results Our data set highlights that Remsima was associated with a significant clinical and biochemical improvement (p&lt;0.01 or less for all parameters assessed) in Crohn’s disease post induction. There were no significant safety issues noted. The total cost saving was £47 800, representing a 38% reduction from originator. Conclusion We found that biosimilar infliximab is as effective as originator infliximab and its use is associated with significant cost savings

    Endothelial Progenitors as Tools to Study Vascular Disease

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    Endothelial progenitor cells (EPCs) have great clinical value because they can be used as diagnostic biomarkers and as a cellular therapy for promoting vascular repair of ischaemic tissues. However, EPCs also have an additional research value in vascular disease modelling to interrogate human disease mechanisms. The term EPC is used to describe a diverse variety of cells, and we have identified a specific EPC subtype called outgrowth endothelial cell (OEC) as the best candidate for vascular disease modelling because of its high-proliferative potential and unambiguous endothelial commitment. OECs are isolated from human blood and can be exposed to pathologic conditions (forward approach) or be isolated from patients (reverse approach) in order to study vascular human disease. The use of OECs for modelling vascular disease will contribute greatly to improving our understanding of endothelial pathogenesis, which will potentially lead to the discovery of novel therapeutic strategies for vascular diseases
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