914 research outputs found

    Do OB Runaway Stars Have Pulsar Companions?

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    We have conducted a VLA search for radio pulsars at the positions of 44 nearby OB runaway stars. The observations involved both searching images for point sources of continuum emission and a time series analysis. Our mean flux sensitivity to pulsars slower than 50 ms was 0.2 mJy. No new pulsars were found in the survey. The size of the survey, combined with the high sensitivity of the observations, sets a significant constraint on the probability, fpf_p, of a runaway OB star having an observable pulsar companion. We find fp≤6.5f_p \le 6.5\% with 95\% confidence, if the general pulsar luminosity function is applicable to OB star pulsar companions. If a pulsar beaming fraction of \onethird\ is assumed, then we estimate that fewer than 20\% of runaway OB stars have neutron star companions, unless pulsed radio emission is frequently obscured by the OB stellar wind. Our result is consistent with the dynamical (or cluster) ejection model for the formation of OB runaways. The supernova ejection model is not ruled out, but is constrained by these observations to allow only a small binary survival fraction, which may be accommodated if neutron stars acquire significant natal kicks. According to Leonard, Hills and Dewey (1994), a 20\% survival fraction corresponds to a 3-d kick velocity of 420 km s−1^{-1}. This value is in close agreement with recent revisions of the pulsar velocity distribution.Comment: Submitted to the Astronomical Journal. 16 pages. Latex uses aaspp4.sty. 3 postscript figures. Address correspondence to Colin Philp ([email protected]). Revision was to replace .ps file with latex fil

    Calibrating EASY-Care independence scale to improve accuracy

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    Background there is currently limited support for the reliability and validity of the EASY-Care independence scale, with little work carried out in low- or middle-income countries. Therefore, we assessed the internal construct validity and hierarchical and classical scaling properties among frail dependent older people in the community. Objective we assessed the internal construct validity and hierarchical and classical scaling properties among frail dependent older people in the community. Methods three primary care physicians administered EASY-Care comprehensive geriatric assessment for 150 frail and/or dependent older people in the primary care setting. A Mokken model was applied to investigate hierarchical scaling properties of EASY-Care independence scale, and internal consistency (Cronbach's alpha) of the scale was also examined. Results we found that EASY-Care independence scale is highly internally consistent and is a strong hierarchical scale, hence providing strong evidence for unidimensionality. However, two items in the scale (unable to use telephone and manage finances) had much lower item Loevinger H coefficients than others. Exclusion of these two items improved the overall internal consistency of the scale. Conclusions the strong performance of the EASY-Care independence scale among community-dwelling frail older people is encouraging. This study confirms that EASY-Care independence scale is highly internally consistent and a strong hierarchical scale

    Aggressive blood pressure control for chronic kidney disease unmasks moyamoya!

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    Hypertensive crises in children or adolescents are rare, but chronic kidney disease (CKD) is a major risk factor for occurrence. Vesicoureteral reflux nephropathy is a common cause of pediatric renal failure and is associated with hypertension. Aggressive blood pressure (BP) control has been shown to delay progression of CKD and treatment is targeted for the 50th percentile for height when compared with a target below the 90th percentile for the general pediatric hypertensive patient. We present a case of an adolescent presenting with seizures and renal failure due to a hypertensive crisis. Hypertension was thought to be secondary to CKD as she had scarred echogenic kidneys due to known reflux nephropathy. However, aggressive BP treatment improved kidney function which is inconsistent with CKD from reflux nephropathy. Secondly, aggressive BP control caused transient neurological symptoms. Further imaging identified moyamoya disease. We present this case to highlight the consideration of moyamoya as a diagnosis in the setting of renal failure and hypertensive crisis

    Identifying common impairments in frail and dependent older people: validation of the COPE assessment for non-specialised health workers in low resource primary health care settings.

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    BACKGROUND: Frail and dependent older people in resource-poor settings are poorly served by health systems that lack outreach capacity. The COPE (Caring for Older PEople) multidimensional assessment tool is designed to help community health workers (CHWs) identify clinically significant impairments and deliver evidence-based interventions METHODS: Older people (n = 150) identified by CHWs as frail or dependent, were assessed at home by the CHW using the structured COPE assessment tool, generating information on impairments in nutrition, mobility, vision, hearing, continence, cognition, mood and behaviour. The older people were reassessed by local physicians who reached a clinical judgment regarding the presence or absence of the same impairments based upon clinical examination guided by the EASY-Care assessment tool. RESULTS: The COPE tool was considered easy to administer, and gave CHWs a sense of empowerment to understand and act upon the needs of older people. Agreement between COPE assessment by CHW and clinician assessors was modest (ranged from 45.8 to 91.3 %) for most impairments. However, the prevalence of impairments was generally higher according to clinicians, particularly for visual impairment (98.7 vs 45.8 %), cognitive impairment (78.4 vs. 38.2 %) and depression (82.0 vs. 59.9 %). Most cases identified by WHO-COPE were clinician confirmed (positive predictive values - 72.2 to 98.5 %), and levels of disability and needs for care among those identified by COPE were higher than those additionally identified by the clinician alone. CONCLUSIONS: The COPE is a feasible tool for the identification of specific impairments in frail dependent older people in the community. Those identified are likely to be confirmed as having clinically relevant problems by clinicians working in the same service, and the COPE may be particularly effective at targeting attention upon those with the most substantial unmet needs

    Identifying common impairments in frail and dependent older people: Validation of the COPE assessment for non-specialised health workers in low resource primary health care settings

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    Background Frail and dependent older people in resource-poor settings are poorly served by health systems that lack outreach capacity. The COPE (Caring for Older PEople) multidimensional assessment tool is designed to help community health workers (CHWs) identify clinically significant impairments and deliver evidence-based interventions Methods Older people (n = 150) identified by CHWs as frail or dependent, were assessed at home by the CHW using the structured COPE assessment tool, generating information on impairments in nutrition, mobility, vision, hearing, continence, cognition, mood and behaviour. The older people were reassessed by local physicians who reached a clinical judgment regarding the presence or absence of the same impairments based upon clinical examination guided by the EASY-Care assessment tool. Results The COPE tool was considered easy to administer, and gave CHWs a sense of empowerment to understand and act upon the needs of older people. Agreement between COPE assessment by CHW and clinician assessors was modest (ranged from 45.8 to 91.3 %) for most impairments. However, the prevalence of impairments was generally higher according to clinicians, particularly for visual impairment (98.7 vs 45.8 %), cognitive impairment (78.4 vs. 38.2 %) and depression (82.0 vs. 59.9 %). Most cases identified by WHO-COPE were clinician confirmed (positive predictive values - 72.2 to 98.5 %), and levels of disability and needs for care among those identified by COPE were higher than those additionally identified by the clinician alone. Conclusions The COPE is a feasible tool for the identification of specific impairments in frail dependent older people in the community. Those identified are likely to be confirmed as having clinically relevant problems by clinicians working in the same service, and the COPE may be particularly effective at targeting attention upon those with the most substantial unmet needs

    Long Intergenic Noncoding RNAs Mediate the Human Chondrocyte Inflammatory Response and Are Differentially Expressed in Osteoarthritis Cartilage

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    Objective To identify long noncoding RNAs (lncRNAs), including long intergenic noncoding RNAs (lincRNAs), antisense RNAs, and pseudogenes, associated with the inflammatory response in human primary osteoarthritis (OA) chondrocytes and to explore their expression and function in OA. Methods OA cartilage was obtained from patients with hip or knee OA following joint replacement surgery. Non-OA cartilage was obtained from postmortem donors and patients with fracture of the neck of the femur. Primary OA chondrocytes were isolated by collagenase digestion. LncRNA expression analysis was performed by RNA sequencing (RNAseq) and quantitative reverse transcriptase-polymerase chain reaction. Modulation of lncRNA chondrocyte expression was achieved using LNA longRNA GapmeRs (Exiqon). Cytokine production was measured with Luminex. Results RNAseq identified 983 lncRNAs in primary human hip OA chondrocytes, 183 of which had not previously been identified. Following interleukin-1β (IL-1β) stimulation, we identified 125 lincRNAs that were differentially expressed. The lincRNA p50-associated cyclooxygenase 2-extragenic RNA (PACER) and 2 novel chondrocyte inflammation-associated lincRNAs (CILinc01 and CILinc02) were differentially expressed in both knee and hip OA cartilage compared to non-OA cartilage. In primary OA chondrocytes, these lincRNAs were rapidly and transiently induced in response to multiple proinflammatory cytokines. Knockdown of CILinc01 and CILinc02 expression in human chondrocytes significantly enhanced the IL-1-stimulated secretion of proinflammatory cytokines. Conclusion The inflammatory response in human OA chondrocytes is associated with widespread changes in the profile of lncRNAs, including PACER, CILinc01, and CILinc02. Differential expression of CILinc01 and CIinc02 in hip and knee OA cartilage, and their role in modulating cytokine production during the chondrocyte inflammatory response, suggest that they may play an important role in mediating inflammation-driven cartilage degeneration in OA

    Depression of the ULF geomagnetic pulsation related to ionospheric irregularities

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    We consider a depression in intensity of ULF magnetic pulsations, which is observed on the ground surface due to appearance of the irregularities in the ionosphere. It is supposed that oblique Alfven waves in the ULF frequency range are downgoing from the magnetosphere and the horizontal irregularities of ionospheric conductivity are created by upgoing atmospheric gravity waves from seismic source. Unlike the companion paper by Molchanov et al. (2003), we used a simple model of the ionospheric layer but took into consideration the lateral inhomogeneity of the perturbation region in the ionosphere. It is shown that ULF intensity could be essentially decreased for frequencies f = 0.001-0.1 Hz at nighttime but the change is negligible at daytime in coincidence with observational results

    eNAMPT Is Localised to Areas of Cartilage Damage in Patients with Hip Osteoarthritis and Promotes Cartilage Catabolism and Inflammation

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    From MDPI via Jisc Publications RouterHistory: accepted 2021-06-21, pub-electronic 2021-06-23Publication status: PublishedFunder: Versus Arthritis; Grant(s): 21530,21812Funder: Medical Research Council; Grant(s): MR/K00414X/1Obesity increases the risk of hip osteoarthritis (OA). Recent studies have shown that adipokine extracellular nicotinamide phosphoribosyltransferase (eNAMPT or visfatin) induces the production of IL-6 and matrix metalloproteases (MMPs) in chondrocytes, suggesting it may promote articular cartilage degradation. However, neither the functional effects of extracellular visfatin on human articular cartilage tissue, nor its expression in the joint of hip OA patients of varying BMI, have been reported. Hip OA joint tissues were collected from patients undergoing joint replacement surgery. Cartilage explants were stimulated with recombinant human visfatin. Pro-inflammatory cytokines and MMPs were measured by ELISA and Luminex. Localisation of visfatin expression in cartilage tissue was determined by immunohistochemistry. Cartilage matrix degradation was determined by quantifying proteoglycan release. Expression of visfatin was elevated in the synovial tissue of hip OA patients who were obese, and was co-localised with MMP-13 in areas of cartilage damage. Visfatin promoted the degradation of hip OA cartilage proteoglycan and induced the production of pro-inflammatory cytokines (IL-6, MCP-1, CCL20, and CCL4) and MMPs. The elevated expression of visfatin in the obese hip OA joint, and its functional effects on hip cartilage tissue, suggests it plays a central role in the loss of cartilage integrity in obese patients with hip OA
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