328 research outputs found

    A model for interacting instabilities and texture dynamics of patterns

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    A simple model to study interacting instabilities and textures of resulting patterns for thermal convection is presented. The model consisting of twelve-mode dynamical system derived for periodic square lattice describes convective patterns in the form of stripes and patchwork quilt. The interaction between stationary zig-zag stripes and standing patchwork quilt pattern leads to spatiotemporal patterns of twisted patchwork quilt. Textures of these patterns, which depend strongly on Prandtl number, are investigated numerically using the model. The model also shows an interesting possibility of a multicritical point, where stability boundaries of four different structures meet.Comment: 4 pages including 4 figures, page width revise

    Symmetry-breaking instability in a prototypical driven granular gas

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    Symmetry-breaking instability of a laterally uniform granular cluster (strip state) in a prototypical driven granular gas is investigated. The system consists of smooth hard disks in a two-dimensional box, colliding inelastically with each other and driven, at zero gravity, by a "thermal" wall. The limit of nearly elastic particle collisions is considered, and granular hydrodynamics with the Jenkins-Richman constitutive relations is employed. The hydrodynamic problem is completely described by two scaled parameters and the aspect ratio of the box. Marginal stability analysis predicts a spontaneous symmetry breaking instability of the strip state, similar to that predicted recently for a different set of constitutive relations. If the system is big enough, the marginal stability curve becomes independent of the details of the boundary condition at the driving wall. In this regime, the density perturbation is exponentially localized at the elastic wall opposite to the thermal wall. The short- and long-wavelength asymptotics of the marginal stability curves are obtained analytically in the dilute limit. The physics of the symmetry-breaking instability is discussed.Comment: 11 pages, 14 figure

    Identifying Residents Who May Benefit from an Analgesic Review: Applying Analgesic Indicators in Residential Aged Care Services.

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    Background Ensuring safe and effective analgesic use in residential aged care services is important because older adults are susceptible to analgesic-related adverse drug events (ADEs). Objective The aim of this study was to identify the proportion and characteristics of residents of aged care services who may benefit from analgesic review based on indicators in the 2021 Society for Post-Acute and Long-Term Care Medicine (AMDA) Pain Management Guideline. Methods Cross-sectional analyses of baseline data from the Frailty in Residential Sector over Time (FIRST) study (N = 550 residents) across 12 South Australian residential aged care services in 2019 were conducted. Indicators included the proportion of residents who received > 3000 mg/day of acetaminophen (paracetamol), regular opioids without a documented clinical rationale, opioid doses > 60 mg morphine equivalents (MME)/day, more than one long-acting opioid concurrently, and a pro re nata (PRN) opioid on more than two occasions in the previous 7 days. Logistic regression was performed to investigate factors associated with residents who may benefit from analgesic review. Results Of 381 (69.3%) residents charted regular acetaminophen, 176 (46.2%) were charted > 3000 mg/day. Of 165 (30%) residents charted regular opioids, only 2 (1.2%) had no prespecified potentially painful conditions in their medical record and 31 (18.8%) received > 60 MME/day. Of 153 (27.8%) residents charted long-acting opioids, 8 (5.2%) received more than one long-acting opioid concurrently. Of 212 (38.5%) residents charted PRN opioids, 10 (4.7%) received more than two administrations in the previous 7 days. Overall, 196 (35.6%) of 550 residents were identified as potentially benefiting from analgesic review. Females (odds ratio [OR] 1.87, 95% confidence interval [CI] 1.20–2.91) and residents with prior fracture (OR 1.62, 95% CI 1.12–2.33) were more likely to be identified. Observed pain (OR 0.50, 95% CI 0.29–0.88) was associated with a lower likelihood of being identified compared with residents with no observed pain. Overall, 43 (7.8%) residents were identified based on opioid-related indicators. Conclusions Up to one in three residents may benefit from a review of their analgesic regimen, including 1 in 13 who may benefit from a specific review of their opioid regimen. Analgesic indicators represent a new approach to target analgesic stewardship interventions.Laura A. Dowd, Amanda J. Cross, Shin J. Liau, Agathe D. Jadczak, Renuka Visvanathan, Felicity C. Veal, J. Simon Bel

    SEDIGISM-ATLASGAL: Dense Gas Fraction and Star Formation Efficiency Across the Galactic Disk

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    By combining two surveys covering a large fraction of the molecular material in the Galactic disk we investigate the role the spiral arms play in the star formation process. We have matched clumps identified by ATLASGAL with their parental GMCs as identified by SEDIGISM, and use these giant molecular cloud (GMC) masses, the bolometric luminosities, and integrated clump masses obtained in a concurrent paper to estimate the dense gas fractions (DGFgmc=Mclump/MgmcDGF_{gmc} = ∑M_{clump}/M_{gmc}) and the instantaneous star forming efficiencies (i.e., SFEgmc=Lclump/MgmcSFE_{gmc} = ∑L_{clump}/M_{gmc}). We find that the molecular material associated with ATLASGAL clumps is concentrated in the spiral arms (∼60 per cent found within ±10 km s1^{−1} of an arm). We have searched for variations in the values of these physical parameters with respect to their proximity to the spiral arms, but find no evidence for any enhancement that might be attributable to the spiral arms. The combined results from a number of similar studies based on different surveys indicate that, while spiral-arm location plays a role in cloud formation and HI to H2_2 conversion, the subsequent star formation processes appear to depend more on local environment effects. This leads us to conclude that the enhanced star formation activity seen towards the spiral arms is the result of source crowding rather than the consequence of a any physical process

    Addition of docetaxel to hormonal therapy in low- and high-burden metastatic hormone sensitive prostate cancer : long-term survival results from the STAMPEDE trial

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    Background STAMPEDE has previously reported that the use of upfront docetaxel improved overall survival (OS) for metastatic hormone naïve prostate cancer patients starting long-term androgen deprivation therapy. We report on long-term outcomes stratified by metastatic burden for M1 patients. Methods We randomly allocated patients in 2 : 1 ratio to standard-of-care (SOC; control group) or SOC + docetaxel. Metastatic disease burden was categorised using retrospectively-collected baseline staging scans where available. Analysis used Cox regression models, adjusted for stratification factors, with emphasis on restricted mean survival time where hazards were non-proportional. Results Between 05 October 2005 and 31 March 2013, 1086 M1 patients were randomised to receive SOC (n = 724) or SOC + docetaxel (n = 362). Metastatic burden was assessable for 830/1086 (76%) patients; 362 (44%) had low and 468 (56%) high metastatic burden. Median follow-up was 78.2 months. There were 494 deaths on SOC (41% more than the previous report). There was good evidence of benefit of docetaxel over SOC on OS (HR = 0.81, 95% CI 0.69–0.95, P = 0.009) with no evidence of heterogeneity of docetaxel effect between metastatic burden sub-groups (interaction P = 0.827). Analysis of other outcomes found evidence of benefit for docetaxel over SOC in failure-free survival (HR = 0.66, 95% CI 0.57–0.76, P  0.5 in each case). There was no evidence that docetaxel resulted in late toxicity compared with SOC: after 1 year, G3-5 toxicity was reported for 28% SOC and 27% docetaxel (in patients still on follow-up at 1 year without prior progression). Conclusions The clinically significant benefit in survival for upfront docetaxel persists at longer follow-up, with no evidence that benefit differed by metastatic burden. We advocate that upfront docetaxel is considered for metastatic hormone naïve prostate cancer patients regardless of metastatic burden

    A review of spatial causal inference methods for environmental and epidemiological applications

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    The scientific rigor and computational methods of causal inference have had great impacts on many disciplines, but have only recently begun to take hold in spatial applications. Spatial casual inference poses analytic challenges due to complex correlation structures and interference between the treatment at one location and the outcomes at others. In this paper, we review the current literature on spatial causal inference and identify areas of future work. We first discuss methods that exploit spatial structure to account for unmeasured confounding variables. We then discuss causal analysis in the presence of spatial interference including several common assumptions used to reduce the complexity of the interference patterns under consideration. These methods are extended to the spatiotemporal case where we compare and contrast the potential outcomes framework with Granger causality, and to geostatistical analyses involving spatial random fields of treatments and responses. The methods are introduced in the context of observational environmental and epidemiological studies, and are compared using both a simulation study and analysis of the effect of ambient air pollution on COVID-19 mortality rate. Code to implement many of the methods using the popular Bayesian software OpenBUGS is provided

    PHIP - a novel candidate breast cancer susceptibility locus on 6q14.1

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    Most non-BRCA1/2 breast cancer families have no identified genetic cause. We used linkage and haplotype analyses in familial and sporadic breast cancer cases to identify a susceptibility locus on chromosome 6q. Two independent genome-wide linkage analysis studies suggested a 3 Mb locus on chromosome 6q and two unrelated Swedish families with a LOD > 2 together seemed to share a haplotype in 6q14.1. We hypothesized that this region harbored a rare high-risk founder allele contributing to breast cancer in these two families. Sequencing of DNA and RNA from the two families did not detect any pathogenic mutations. Finally, 29 SNPs in the region were analyzed in 44,214 cases and 43,532 controls from BCAC, and the original haplotypes in the two families were suggested as low-risk alleles for European and Swedish women specifically. There was also some support for one additional independent moderate-risk allele in Swedish familial samples. The results were consistent with our previous findings in familial breast cancer and supported a breast cancer susceptibility locus at 6q14.1 around the PHIP gene.Peer reviewe

    IBD Serology and Disease Outcomes in African Americans with Crohn's Disease

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    Backgrounds: Recent studies have identified the role of serologic markers in characterizing disease phenotype, location, complications, and severity among Northern Europeans (NE) with Crohn's disease (CD). However, very little is known about the role of serology in CD among African Americans (AA). Our study explored the relationship between serology and disease phenotype in AA with CD, while controlling for genetic ancestry. Methods: AAs with CD were enrolled as participants through multicenter collaborative efforts. Serological levels of IgA anti-Saccharomyces cervisiae antibody (ASCA), IgG ASCA, E. coli outermembrane porin C, anti-CBir1, and ANCA were measured using enzyme-linked immunosorbent assays. Genotyping was performed using Illumina immunochip technology; an admixture rate was calculated for each subject. Multiple imputation by chained equations was performed to account for data missing at random. Logistic regression was used to calculate adjusted odds ratio (OR) for associations between serological markers and both complicated disease and disease requiring surgery. Results: A total of 358 patients were included in the analysis. The majority of our patients had inflammatory, noncomplicated disease (58.4%), perianal disease (55.7%), and documented colonic inflammation (86.8%). On multivariable analysis, both IgG ASCA and OmpC were associated with complicated disease (OR, 2.67; 95% CI, 1.67-4.28; OR, 2.23; 95% CI, 1.41-3.53, respectively) and disease requiring surgery (OR, 2.51; 95% CI, 1.49-4.22; OR, 3.57; 95% CI, 2.12-6.00). NE admixture to the African genome did not have any associations or interactions in relation to clinical outcome. Conclusions: Our study comprises the largest cohort of AAs with CD. The utility of serological markers for the prognosis of CD in NE applies equally to AA populations
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