434 research outputs found

    Approximate Jacobians for the Solution of the Euler and Navier-Stokes Equations. G.U. Aero Report 9705

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    This paper describes a method for efficiently solving the steady-state Euler and Navier-Stokes equations. Robustness is achieved through the use of an upwind TVD scheme for discretising the convective terms. The approximate solution is advanced in time implicitly and the linear system arising at each implicit step is solved using a Conjugate Gradient type method. The main emphasis of this paper is on the use of Jacobian matrices associated with a simpler spatial discretisation. This leads to better conditioned linear systems. The resulting method has lower memory and CPU-time requirements when compared with the one using exact Jacobians

    Does regulating private long-term care facilities lead to better care? a study from Quebec, Canada

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    Objective. In the province of Quebec, Canada, long-term residential care is provided by 2 types of facilities: publicly-funded accredited facilities and privately-owned facilities in which care is privately financed and delivered. Following evidence that private facilities were delivering inadequate care, the provincial government decided to regulate this industry. We assessed the impact of regulation on care quality by comparing quality assessments made before and after regulation. In both periods, public facilities served as a comparison group. Design: A cross-sectional study conducted in 2010-2012 that incorporates data collected in 1995-2000. Settings. Random samples of private and public facilities from 2 regions of Quebec. Participants. Random samples of disabled residents aged 65 years and over. In total, 451 residents from 145 care settings assessed in 1995-2000 were compared to 329 residents from 102 care settings assessed in 2010-2012. Intervention. Regulation introduced by the province in 2005, effective February 2007. Main outcome measure. Quality of care measured with the QUALCARE Scale. Results. After regulation, fewer small-size facilities were in operation in the private market. Between the 2 study periods, the proportion of residents with severe disabilities decreased in private facilities while it remained over 80% in their public counterparts. Meanwhile, quality of care improved significantly in private facilities, while worsening in their public counterparts, even after controlling for confounding. Conclusions. The private industry now provides better care to its residents. Improvement in care quality likely results in part from the closure of small homes and change in resident case-mix

    Discovery of the Optical Transient of the Gamma Ray Burst 990308

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    The optical transient of the faint Gamma Ray Burst 990308 was detected by the QUEST camera on the Venezuelan 1-m Schmidt telescope starting 3.28 hours after the burst. Our photometry gives V=18.32±0.07V = 18.32 \pm 0.07, R=18.14±0.06R = 18.14 \pm 0.06, B=18.65±0.23B = 18.65 \pm 0.23, and R=18.22±0.05R = 18.22 \pm 0.05 for times ranging from 3.28 to 3.47 hours after the burst. The colors correspond to a spectral slope of close to fνν1/3f_{\nu} \propto \nu^{1/3}. Within the standard synchrotron fireball model, this requires that the external medium be less dense than 104cm310^{4} cm^{-3}, the electrons contain >20> 20% of the shock energy, and the magnetic field energy must be less than 24% of the energy in the electrons for normal interstellar or circumstellar densities. We also report upper limits of V>12.0V > 12.0 at 132 s (with LOTIS), V>13.4V > 13.4 from 132-1029s (with LOTIS), V>15.3V > 15.3 at 28.2 min (with Super-LOTIS), and a 8.5 GHz flux of <114μJy< 114 \mu Jy at 110 days (with the Very Large Array). WIYN 3.5-m and Keck 10-m telescopes reveal this location to be empty of any host galaxy to R>25.7R > 25.7 and K>23.3K > 23.3. The lack of a host galaxy likely implies that it is either substantially subluminous or more distant than a red shift of 1.2\sim 1.2.Comment: ApJ Lett submitted, 5 pages, 2 figures, no space for 12 coauthor

    Understanding the small object argument

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    The small object argument is a transfinite construction which, starting from a set of maps in a category, generates a weak factorisation system on that category. As useful as it is, the small object argument has some problematic aspects: it possesses no universal property; it does not converge; and it does not seem to be related to other transfinite constructions occurring in categorical algebra. In this paper, we give an "algebraic" refinement of the small object argument, cast in terms of Grandis and Tholen's natural weak factorisation systems, which rectifies each of these three deficiencies.Comment: 42 pages; supersedes the earlier arXiv preprint math/0702290; v2: final journal version, minor corrections onl

    Multicentre, prospective, open study to evaluate the safety and efficacy of hylan G-F 20 in knee osteoarthritis subjects presenting with pain following arthroscopic meniscectomy

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    The aim of the study was to evaluate the safety and efficacy of viscosupplementation with hylan G-F 20 in patients with mild to moderate osteoarthritis (OA) presenting with persistent knee pain 4–12 weeks after arthroscopic meniscectomy. A prospective, multi-centre, open study was carried out in patients with pain due to OA of the knee, not resolved by simple analgesics, 4–12 weeks after undergoing arthroscopic meniscectomy. To be eligible, patients had to score ≥50 mm and ≤90 mm on both walking pain and patient global assessment visual analogue scales (VAS; 0–100 mm) at baseline and be radiologically diagnosed pre-operatively with OA grade I or II on the Kellgren-Lawrence scale, with <50% joint space narrowing. Patients received three intra-articular, 2 ml injections of hylan G-F 20 in the target knee with an interval of 1 week between injections, and were followed for 52 weeks. The primary efficacy endpoint was the change from baseline in the walking pain VAS score at 26 weeks. Secondary outcome measures were the walking pain VAS scores at all other time points, the WOMAC Index at all time points, and patient and physician global assessment at all time points. The safety of the treatment was assessed using adverse event (AE) reports. A total of 62 patients (mean age 55.4 years, 52% male) were enrolled. The mean walking pain VAS score decreased by 36.8 mm from baseline at 26 weeks (P < 0.0001), and also showed statistically significant decreases (P < 0.0001) at all other time points. The change in WOMAC total and subscale scores from baseline were statistically significant (P < 0.0001) at all time points, as were the decreases in the physician and patient global assessment VAS scores. There were 18 target knee AEs (mostly pain and/or swelling and/or effusion) in 12 patients (19%) considered to be at least possibly related to treatment. The majority of these (78%) were mild or moderate in intensity. One patient (1.6%) experienced a serious adverse event (synovitis) in the target knee that was considered possibly related to study treatment. Hylan G-F 20 provides effective pain relief and improves stiffness and physical function in patients with mild to moderate OA presenting with persistent osteoarthritic pain 4–12 weeks after arthroscopic meniscectomy. Symptomatic efficacy was maximised at 12 weeks and maintained at 26 and 52 weeks. The type (pain and/or swelling and/or effusion) and the intensity (mostly mild/moderate) of AEs reported in this study are similar to those reported in other trials in different patient populations, but the incidence was higher (19%). The risk/benefit of hylan G-F 20 in this particular population of patients is favourable

    Meeting the home-care needs of disabled older persons living in the community: does integrated services delivery make a difference?

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    <p>Abstract</p> <p>Background</p> <p>The PRISMA Model is an innovative coordination-type integrated-service-delivery (ISD) network designed to manage and better match resources to the complex and evolving needs of elders. The goal of this study was to examine the impact of this ISD network on unmet needs among disabled older persons living in the community.</p> <p>Methods</p> <p>Using data from the PRISMA study, we compared unmet needs of elders living in the community in areas with or without an ISD network. Disabilities and unmet needs were assessed with the Functional Autonomy Measurement System (SMAF). We used growth-curve analysis to examine changes in unmet needs over time and the variables associated with initial status and change. Sociodemographic characteristics, level of disability, self-perceived health status, cognitive functioning, level of empowerment, and the hours of care received were investigated as covariates. Lastly, we report the prevalence of needs and unmet needs for 29 activities in both areas at the end of the study.</p> <p>Results</p> <p>On average, participants were 83 years old; 62% were women. They had a moderate level of disability and mild cognitive problems. On average, they received 2.07 hours/day (SD = 1.08) of disability-related care, mostly provided by family. The findings from growth-curve analysis suggest that elders living in the area where ISD was implemented and those with higher levels of disability experience better fulfillment of their needs over time. Besides the area, being a woman, living alone, having a higher level of disability, more cognitive impairments, and a lower level of empowerment were linked to initial unmet needs (r<sup>2 </sup>= 0.25; p < 0.001). At the end of the study, 35% (95% CI: 31% to 40%) of elders with needs living in the ISD area had at least one unmet need, compared to 67% (95% CI: 62% to 71%) in the other area. In general, unmet needs were highest for bathing, grooming, urinary incontinence, walking outside, seeing, hearing, preparing meals, and taking medications.</p> <p>Conclusions</p> <p>In spite of more than 30 years of home-care services in the province of Quebec, disabled older adults living in the community still have unmet needs. ISD networks such as the PRISMA Model, however, appear to offer an effective response to the long-term-care needs of the elderly.</p

    The RNA-Binding Protein Musashi1 Affects Medulloblastoma Growth via a Network of Cancer- Related Genes and Is an Indicator of Poor Prognosis

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    Musashi1 (Msi1) is a highly conserved RNA-binding protein that is required during the development of the nervous system. Msi1 has been characterized as a stem cell marker, controlling the balance between self-renewal and differentiation, and has also been implicated in tumorigenesis, being highly expressed in multiple tumor types. We analyzed Msi1 expression in a large cohort of medulloblastoma samples and found that Msi1 is highly expressed in tumor tissue compared with normal cerebellum. Notably, high Msi1 expression levels proved to be a sign of poor prognosis. Msi1 expression was determined to be particularly high in molecular subgroups 3 and 4 of medulloblastoma. We determined that Msi1 is required for tumorigenesis because inhibition of Msi1 expression by small-interfering RNAs reduced the growth of Daoy medulloblastoma cells in xenografts. To characterize the participation of Msi1 in medulloblastoma, we conducted different high-throughput analyses. Ribonucleoprotein immunoprecipitation followed by microarray analysis (RIP-chip) was used to identify mRNA species preferentially associated with Msi1 protein in Daoy cells. We also used cluster analysis to identify genes with similar or opposite expression patterns to Msi1 in our medulloblastoma cohort. A network study identified RAC1, CTGF, SDCBP, SRC, PRL, and SHC1 as major nodes of an Msi1-associated network. Our results suggest that Msi1 functions as a regulator of multiple processes in medulloblastoma formation and could become an important therapeutic target
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