146 research outputs found

    The BAT AGN Spectroscopic Survey -- XVIII. Searching for Supermassive Black Hole Binaries in the X-rays

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    Theory predicts that a supermassive black hole binary (SMBHB) could be observed as a luminous active galactic nucleus (AGN) that periodically varies on the order of its orbital timescale. In X-rays, periodic variations could be caused by mechanisms including relativistic Doppler boosting and shocks. Here we present the first systematic search for periodic AGNs using 941941 hard X-ray light curves (14-195 keV) from the first 105 months of the Swift Burst Alert Telescope (BAT) survey (2004-2013). We do not find evidence for periodic AGNs in Swift-BAT, including the previously reported SMBHB candidate MCG+11-11-032. We find that the null detection is consistent with the combination of the upper-limit binary population in AGNs in our adopted model, their expected periodic variability amplitudes, and the BAT survey characteristics. We have also investigated the detectability of SMBHBs against normal AGN X-ray variability in the context of the eROSITA survey. Under our assumptions of a binary population and the periodic signals they produce which have long periods of hundreds of days, up to 1313% true periodic binaries can be robustly distinguished from normal variable AGNs with the ideal uniform sampling. However, we demonstrate that realistic eROSITA sampling is likely to be insensitive to long-period binaries because longer observing gaps reduce their detectability. In contrast, large observing gaps do not diminish the prospect of detecting binaries of short, few-day periods, as 19% can be successfully recovered, the vast majority of which can be identified by the first half of the survey.Comment: 17 pages, including 8 figures and 4 tables. Accepted for publication in Ap

    Comparing recruitment strategies in a study of acupuncture for chronic back pain

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    <p>Abstract</p> <p>Background</p> <p>Meeting recruitment goals is challenging for many clinical trials conducted in primary care populations. Little is known about how the use of different recruitment strategies affects the types of individuals choosing to participate or the conclusions of the study.</p> <p>Methods</p> <p>A secondary analysis was performed using data from participants recruited to a clinical trial evaluating acupuncture for chronic back pain among primary care patients in a large integrated health care organization. We used two recruitment methods: mailed letters of invitation and an advertisement in the health plan's magazine. For these two recruitment methods, we compared recruitment success (% randomized, treatment completers, drop outs and losses to follow-up), participant characteristics, and primary clinical outcomes. A linear regression model was used to test for interaction between treatment group and recruitment method.</p> <p>Results</p> <p>Participants recruited via mailed letters closely resembled those responding to the advertisement in terms of demographic characteristics, most aspects of their back pain history and current episode and beliefs and expectations about acupuncture. No interaction between method of recruitment and treatment group was seen, suggesting that study outcomes were not affected by recruitment strategy.</p> <p>Conclusion</p> <p>In this trial, the two recruitment strategies yielded similar estimates of treatment effectiveness. However, because this finding may not apply to other recruitment strategies or trial circumstances, trials employing multiple recruitment strategies should evaluate the effect of recruitment strategy on outcome.</p> <p>Trial registration</p> <p>Clinical Trials.gov NCT00065585.</p

    Characteristics of patients with chronic back pain who benefit from acupuncture

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    <p>Abstract</p> <p>Background</p> <p>Although many clinicians believe there are clinically important subgroups of persons with "non-specific" low back pain, such subgroups have not yet been clearly identified. As part of a large trial evaluating acupuncture for chronic low back pain, we sought to identify subgroups of participants that were particularly responsive to acupuncture.</p> <p>Methods</p> <p>We performed a secondary analysis of data for the 638 participants in our clinical trial comparing different types of acupuncture to usual care to identify baseline characteristics that predicted responses to individualized, standardized, or simulated acupuncture treatments. After identifying factors that predicted improvements in back-related function or symptoms, we determined if these factors were more likely to predict improvement for those receiving the acupuncture treatments than for those receiving usual care. This was accomplished by testing for an interaction between the prognostic factors and treatment group in four models: functional outcomes (measured by the Roland-Morris Disability Scale) at 8 and 52 weeks post-randomization and symptom outcomes (measured with a numerical rating scale) at 8 and 52 weeks.</p> <p>Results</p> <p>Overall, the strongest predictors of improvement in back function and symptoms were higher baseline levels of these measures, receipt of an acupuncture treatment, and non-use of narcotic analgesics. Benefit from acupuncture compared to usual care was greater with worse pre-treatment levels of back dysfunction (interaction p < 0.004 for the functional outcome, Roland Morris Disability Scale at 8 weeks). No other consistent interactions were observed.</p> <p>Conclusion</p> <p>This secondary analysis found little evidence for the existence of subgroups of patients with chronic back pain that would be especially likely to benefit from acupuncture. However, persons with chronic low back pain who had more severe baseline dysfunction had the most short-term benefit from acupuncture.</p

    An ex vivo system to study cellular dynamics underlying mouse peri-implantation development

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    マウスの着床期の胚発生を三次元で再現することに成功. 京都大学プレスリリース. 2022-02-09.Upon implantation, mammalian embryos undergo major morphogenesis and key developmental processes such as body axis specification and gastrulation. However, limited accessibility obscures the study of these crucial processes. Here, we develop an ex vivo Matrigel-collagen-based culture to recapitulate mouse development from E4.5 to E6.0. Our system not only recapitulates embryonic growth, axis initiation, and overall 3D architecture in 49% of the cases, but its compatibility with light-sheet microscopy also enables the study of cellular dynamics through automatic cell segmentation. We find that, upon implantation, release of the increasing tension in the polar trophectoderm is necessary for its constriction and invagination. The resulting extra-embryonic ectoderm plays a key role in growth, morphogenesis, and patterning of the neighboring epiblast, which subsequently gives rise to all embryonic tissues. This 3D ex vivo system thus offers unprecedented access to peri-implantation development for in toto monitoring, measurement, and spatiotemporally controlled perturbation, revealing a mechano-chemical interplay between extra-embryonic and embryonic tissues

    The BAT AGN Spectroscopic Survey. XVIII. Searching for Supermassive Black Hole Binaries in X-Rays

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    Theory predicts that a supermassive black hole binary (SMBHB) could be observed as a luminous active galactic nucleus (AGN) that periodically varies on the order of its orbital timescale. In X-rays, periodic variations could be caused by mechanisms including relativistic Doppler boosting and shocks. Here we present the first systematic search for periodic AGNs using 941 hard X-ray light curves (14–195 keV) from the first 105 months of the Swift Burst Alert Telescope (BAT) survey (2004–2013). We do not find evidence for periodic AGNs in Swift-BAT, including the previously reported SMBHB candidate MCG+11−11−032. We find that the null detection is consistent with the combination of the upper-limit binary population in AGNs in our adopted model, their expected periodic variability amplitudes, and the BAT survey characteristics. We have also investigated the detectability of SMBHBs against normal AGN X-ray variability in the context of the extended ROentgen Survey with an Imaging Telescope Array (eROSITA) survey. Under our assumptions of a binary population and the periodic signals they produce, which have long periods of hundreds of days, up to 13% true periodic binaries can be robustly distinguished from normal variable AGNs with the ideal uniform sampling. However, we demonstrate that realistic eROSITA sampling is likely to be insensitive to long-period binaries because longer observing gaps reduce their detectability. In contrast, large observing gaps do not diminish the prospect of detecting binaries of short, few-day periods, as 19% can be successfully recovered, the vast majority of which can be identified by the first half of the survey

    Vascular Endothelial Adrenomedullin-RAMP2 System Is Essential for Vascular Integrity and Organ Homeostasis

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    信州大学博士(医学)・学位論文・平成25年3月31日授与(甲第935号)・小山 晃英Background-Revealing the mechanisms underlying the functional integrity of the vascular system could make available novel therapeutic approaches. We previously showed that knocking out the widely expressed peptide adrenomedullin (AM) or receptor activity-modifying protein 2 (RAMP2), an AM-receptor accessory protein, causes vascular abnormalities and is embryonically lethal. Our aim was to investigate the function of the vascular AM-RAMP2 system directly. Methods and Results-We generated endothelial cell-specific RAMP2 and AM knockout mice (E-RAMP2(-/-) and E-AM(-/-)). Most E-RAMP2(-/-) mice died perinatally. In surviving adults, vasculitis occurred spontaneously. With aging, E-RAMP2(-/-) mice showed severe organ fibrosis with marked oxidative stress and accelerated vascular senescence. Later, liver cirrhosis, cardiac fibrosis, and hydronephrosis developed. We next used a line of drug-inducible E-RAMP2(-/-) mice (DI-E-RAMP2(-/-)) to induce RAMP2 deletion in adults, which enabled us to analyze the initial causes of the aforementioned vascular and organ damage. Early after the induction, pronounced edema with enhanced vascular leakage occurred. In vitro analysis revealed the vascular leakage to be caused by actin disarrangement and detachment of endothelial cells. We found that the AM-RAMP2 system regulates the Rac1-GTP/RhoA-GTP ratio and cortical actin formation and that a defect in this system causes the disruption of actin formation, leading to vascular and organ damage at the chronic stage after the gene deletion. Conclusions-Our findings show that the AM-RAMP2 system is a key determinant of vascular integrity and homeostasis from prenatal stages through adulthood. Furthermore, our models demonstrate how endothelial cells regulate vascular integrity and how their dysregulation leads to organ damage. (Circulation. 2013;127:842-853.)ArticleCIRCULATION. 127(7):842-853 (2013)journal articl

    Breast MRI in Community Practice: Equipment and Imaging Techniques at Facilities in the Breast Cancer Surveillance Consortium

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    MRI is increasingly used for detection of breast carcinoma. Little is known about breast MRI techniques among community practice facilities. This study evaluated equipment and acquisition techniques used by community facilities across the U.S., including compliance with minimum standards by the American College of Radiology Imaging Network (ACRIN) 6667 Trial and the European Society of Breast Imaging (EUSOBI)

    FANERÓGAMAS NA ARBORIZAÇÃO DA AVENIDA ARAUCÁRIA, FOZ DO IGUAÇU – PR – BRASIL

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    A arborização das cidades surgiu da necessidade de se manter o vínculo entre população urbana e a natureza. Quando realizada de maneira adequada, ela garante a prestação de serviços ambientais como regulação microclimática, redução da poluição atmosférica e sonora, conservação da biodiversidade nativa e melhoria estética das cidades. Foz do Iguaçu com uma área considerável de remanescentes florestais, belezas naturais e potencial turístico, não possui um projeto adequado de arborização. Nesse sentido, este trabalho se propôs a realizar um levantamento das fanerógamas na Avenida Araucária, no bairro Vila A, em Foz do Iguaçu - PR, Brasil, seus usos potenciais e síndromes de dispersão, de modo a contribuir com informações básicas para o plano de arborização do município. As coletas se deram entre meses de 2018 e 2019, as amostras coletadas foram herborizadas, identificadas e incorporadas ao herbário EVB. Assim, foram identificadas 59 espécies circunscritas em 26 famílias, sendo as mais representativas Fabaceae (21 spp.) e Moraceae (4 spp.), 56,7% são nativas e 43,3% exóticas, 22 das espécies nativas são comuns em florestas estacionais. As principais formas de dispersão foram zoocoria, anemocoria e autocoria, de polinização, a entomofilia. Dentre as espécies encontradas, nota-se um número considerável de espécies inapropriadas para o plantio em cidades, como espécies invasoras e exóticas e/ou tóxicas. Os dados levantados evidenciam a necessidade de um plano de arborização relacionado com o fornecimento de serviços ecossistêmicos essenciais para a promoção do bem-estar, saúde pública e qualidade ambiental na cidade

    Patterns of Breast Magnetic Resonance Imaging Use in Community Practice

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    Breast magnetic resonance imaging (MRI) is increasingly used for breast cancer screening, diagnostic evaluation, and surveillance However, we lack data on national patterns of breast MRI use in community practice

    Breast MRI BI-RADS Assessments and Abnormal Interpretation Rates by Clinical Indication in US Community Practices

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    As breast MRI use grows, benchmark performance parameters are needed for auditing and quality assurance purposes. We describe the variation in breast MRI abnormal interpretation rates (AIRs) by clinical indication among a large sample of U.S. community practices
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