874 research outputs found
The value of high-resolution Met Office regional climate models in the simulation of multi-hourly precipitation extremes
Open access articleExtreme value theory is used as a diagnostic for two high-resolution (12-km parameterized convection and 1.5-km explicit convection) Met Office regional climate model (RCM) simulations. On subdaily time scales, the 12-km simulation has weaker June–August (JJA) short-return-period return levels than the 1.5-km RCM, yet the 12-km RCM has overly large high return levels. Comparisons with observations indicate that the 1.5-km RCM is more successful than the 12-km RCM in representing (multi)hourly JJA very extreme events. As accumulation periods increase toward daily time scales, the erroneous 12-km precipitation extremes become more comparable with the observations and the 1.5-km RCM. The 12-km RCM fails to capture the observed low sensitivity of the growth rate to accumulation period changes, which is successfully captured by the 1.5-km RCM. Both simulations have comparable December–February (DJF) extremes, but the DJF extremes are generally weaker than in JJA at daily or shorter time scales. Case studies indicate that “gridpoint storms” are one of the causes of unrealistic very extreme events in the 12-km RCM. Caution is needed in interpreting the realism of 12-km RCM JJA extremes, including short-return-period events, which have return values closer to observations. There is clear evidence that the 1.5-km RCM has a higher degree of realism than the 12-km RCM in the simulation of JJA extremes.Natural Environment Research Council (NERC)UKMONewcastle Universit
Dietary patterns during high school and risk of colorectal adenoma in a cohort of middle-aged women
Adolescent diet may be etiologically relevant for later risk of colorectal adenoma, a precursor of colorectal cancer. We aimed to examine associations between adolescent dietary patterns (derived using factor analysis) and risk of colorectal adenoma in middle adulthood. We analyzed data from 17,221 women participating in the Nurses' Health Study II, who had completed a validated high school (HS) food frequency questionnaire in 1998 when they were 34-51 years old, and had subsequently undergone at least one lower bowel endoscopy. Between 1998 and 2007, 1,299 women were diagnosed with at least one colorectal adenoma. In multivariable models adjusted for adult dietary patterns, a higher "prudent" pattern during HS, characterized by high consumption of vegetables, fruit and fish was associated with a statistically significantly lower risk of rectal (odds ratio [OR] highest vs. lowest quintile, 0.45, 95% CI 0.27-0.75, p-trend=0.005), but not colon adenomas. A higher "Western" pattern during HS, characterized by high consumption of desserts and sweets, snack foods and red and processed meat, was significantly associated with rectal (OR 1.78, 95% CI 1.12-2.85, p-trend=0.005) and advanced (OR 1.58, 95% CI 1.07-2.33, p-trend=0.08), but not associated with colon or non-advanced adenomas. This study suggests that overall eating patterns during high school may influence later risk of rectal and advanced adenoma, independent of adult diet. Our results support the hypothesis that diet during early life may influence colorectal carcinogenesis
Dynamic Clustering of Histogram Data Based on Adaptive Squared Wasserstein Distances
This paper deals with clustering methods based on adaptive distances for
histogram data using a dynamic clustering algorithm. Histogram data describes
individuals in terms of empirical distributions. These kind of data can be
considered as complex descriptions of phenomena observed on complex objects:
images, groups of individuals, spatial or temporal variant data, results of
queries, environmental data, and so on. The Wasserstein distance is used to
compare two histograms. The Wasserstein distance between histograms is
constituted by two components: the first based on the means, and the second, to
internal dispersions (standard deviation, skewness, kurtosis, and so on) of the
histograms. To cluster sets of histogram data, we propose to use Dynamic
Clustering Algorithm, (based on adaptive squared Wasserstein distances) that is
a k-means-like algorithm for clustering a set of individuals into classes
that are apriori fixed.
The main aim of this research is to provide a tool for clustering histograms,
emphasizing the different contributions of the histogram variables, and their
components, to the definition of the clusters. We demonstrate that this can be
achieved using adaptive distances. Two kind of adaptive distances are
considered: the first takes into account the variability of each component of
each descriptor for the whole set of individuals; the second takes into account
the variability of each component of each descriptor in each cluster. We
furnish interpretative tools of the obtained partition based on an extension of
the classical measures (indexes) to the use of adaptive distances in the
clustering criterion function. Applications on synthetic and real-world data
corroborate the proposed procedure
Empowering workplace allies for lesbian, gay, bisexual, and transgender employees to prevent and minimize psychological distress: A scoping review
Introduction
Lesbian, gay, bisexual, and transgender (LGBT) employees have increasingly reported experiencing different forms of workplace discrimination/harassment. Workplace allyship may be positively associated with psychological health through creating inclusive organizational cultures or reducing discrimination/harassment. However, comprehensive literature reviews or evidence syntheses on the effects of workplace allyship in mental health protection/promotion for LGBT employees are limited.
Methods
This scoping review aimed to summarize available evidence regarding the effectiveness of workplace allies for LGBT employees in preventing/minimizing psychological distress and clarify the therapeutic components. This review included published research articles and grey literature identified through 11 electronic databases, a secondary search, and other sources.
Results
We identified 27 relevant articles. Most included studies used cross-sectional or qualitative research designs, and evidence from countries beyond the United States was limited. Three essential/effective components of workplace allies/allyship were identified that could create supportive/safe workplace relationships/climates: (a) knowledge, (b) empathy, and (c) action.
Conclusions
Further longitudinal studies and controlled trials are needed to increase the quality of evidence on the effects and change processes induced by workplace allyship. Qualitative studies are also recommended to understand the health needs and mechanism of actions of workplace allyships in different LGBT communities
Reactive organoallyl species generated from aryl halides and allene: allylation of alpha,beta-unsaturated aldehydes and cyclic ketones employing Pd/In transmetallation processes
Allylation of α,β-unsaturated aldehydes and cyclic ketones promoted by Pd/In transmetallation processes has been studied. The unsaturated aldehydes underwent regioselective 1,2-addition to afford secondary homoally alcohols. The reactions have been performed using Pd(OAc)2/PPh3 as catalytic system and metallic indium affording the products in good yields. The same transformation with unsaturated ketones proved to be less efficient, while saturated cyclic ketones delivered generally excellent yields in the presence of CuI. In these latter processes the presence of a distal heteroatom influences the reaction rate
Vedolizumab Is Associated With a Lower Risk of Serious Infections Than Anti-Tumor Necrosis Factor Agents in Older Adults
Background & Aims: Despite the increased numbers of older adults with inflammatory bowel diseases (IBDs), there are few studies regarding the safety and effectiveness of IBD treatments in older adults. The aim of this study was to compare the safety and effectiveness of anti–tumor necrosis factor (TNF)-α agents and vedolizumab in older adults with IBD. Methods: We conducted a retrospective cohort study using an active comparator, new-user design for adults age 65 years and older with IBD initiating anti–TNF-α agents and vedolizumab in the Medicare claims database from 2014 to 2017. The primary safety outcome was infection-related hospitalization (excluding intra-abdominal and perianal abscesses). Co-primary outcomes to estimate effectiveness were IBD-related hospitalization, IBD-related surgery, and new corticosteroid use 60 days or more after biologic initiation. We performed propensity score weighting to control for confounding and estimated adjusted hazard ratios and 95% confidence intervals using standardized morbidity ratio–weighted variables. Results: We identified 1152 anti–TNF-α new users and 480 vedolizumab new users. The median age was 71 years in both cohorts and 11% were age 80 years or older. Crohn's disease patients comprised 54% of the anti–TNF-α cohort and 57% of the vedolizumab cohort. There was no significant difference in demographics, health care utilization, or frailty in both cohorts. More than half of both cohorts had a Charlson comorbidity index of 2 or higher. Vedolizumab users had a decreased risk of infection-related hospitalization (adjusted hazard ratio, 0.47; 95% confidence interval, 0.25–0.86). There was no significant difference in the outcomes approximating effectiveness. Conclusions: Older IBD patients treated with vedolizumab had a lower risk of infection-related hospitalization compared with those initiating anti-TNFs. We observed no difference in effectiveness defined by hospitalizations, surgery, or new corticosteroid use
Network Rewiring of Homologous Recombination Enzymes during Mitotic Proliferation and Meiosis.
Homologous recombination (HR) is essential for high-fidelity DNA repair during mitotic proliferation and meiosis. Yet, context-specific modifications must tailor the recombination machinery to avoid (mitosis) or enforce (meiosis) the formation of reciprocal exchanges-crossovers-between recombining chromosomes. To obtain molecular insight into how crossover control is achieved, we affinity purified 7 DNA-processing enzymes that channel HR intermediates into crossovers or noncrossovers from vegetative cells or cells undergoing meiosis. Using mass spectrometry, we provide a global characterization of their composition and reveal mitosis- and meiosis-specific modules in the interaction networks. Functional analyses of meiosis-specific interactors of MutLÎł-Exo1 identified Rtk1, Caf120, and Chd1 as regulators of crossing-over. Chd1, which transiently associates with Exo1 at the prophase-to-metaphase I transition, enables the formation of MutLÎł-dependent crossovers through its conserved ability to bind and displace nucleosomes. Thus, rewiring of the HR network, coupled to chromatin remodeling, promotes context-specific control of the recombination outcome
Comparison of some Reduced Representation Approximations
In the field of numerical approximation, specialists considering highly
complex problems have recently proposed various ways to simplify their
underlying problems. In this field, depending on the problem they were tackling
and the community that are at work, different approaches have been developed
with some success and have even gained some maturity, the applications can now
be applied to information analysis or for numerical simulation of PDE's. At
this point, a crossed analysis and effort for understanding the similarities
and the differences between these approaches that found their starting points
in different backgrounds is of interest. It is the purpose of this paper to
contribute to this effort by comparing some constructive reduced
representations of complex functions. We present here in full details the
Adaptive Cross Approximation (ACA) and the Empirical Interpolation Method (EIM)
together with other approaches that enter in the same category
Emergence of a novel GII.17 norovirus – end of the GII.4 era?
In the winter of 2014/15 a novel GII.P17-GII.17 norovirus strain (GII.17 Kawasaki 2014) emerged, as a major cause of gastroenteritis outbreaks in China and Japan. Since their emergence these novel GII.P17-GII.17 viruses have replaced the previously dominant GII.4 genotype Sydney 2012 variant in some areas in Asia but were only detected in a limited number of cases on other continents. This perspective provides an overview of the available information on GII.17 viruses in order to gain insight in the viral and host characteristics of this norovirus genotype. We further discuss the emergence of this novel GII.P17-GII.17 norovirus in context of current knowledge on the epidemiology of noroviruses. It remains to be seen if the currently dominant norovirus strain GII.4 Sydney 2012 will be replaced in other parts of the world. Nevertheless, the public health community and surveillance systems need to be prepared in case of a potential increase of norovirus activity in the next seasons caused by this novel GII.P17-GII.17 norovirus
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