252 research outputs found

    A matrix isolation and computational study of molecular palladium fluorides : does PdF₆ exist?

    Get PDF
    Palladium atoms generated by thermal evaporation and laser ablation were reacted with and trapped in F₂ /Ar, F₂ /Ne, and neat F₂ matrices. The products were characterized by electronic absorption and infrared spectroscopy, together with relativistic density functional theory calculations as well as coupled cluster calculations. Vibrational modes at 540 and 617 cm⁻Âč in argon matrices were assigned to molecular PdF and PdF₂ , and a band at 692 cm⁻Âč was assigned to molecular PdF₄ . A band at 624 cm⁻Âč can be assigned to either PdF₃ or PdF₆, with the former preferred from experimental considerations. Although calculations might support the latter assignment, our conclusion is that in these detailed experiments there is no convincing evidence for PdF₆

    A framework for considering the utility of models when facing tough decisions in public health: a guideline for policy-makers

    Get PDF
    The COVID-19 pandemic has brought the combined disciplines of public health, infectious disease and policy modelling squarely into the spotlight. Never before have decisions regarding public health measures and their impacts been such a topic of international deliberation, from the level of individuals and communities through to global leaders. Nor have models-developed at rapid pace and often in the absence of complete information-ever been so central to the decision-making process. However, after nearly 3 years of experience with modelling, policy-makers need to be more confident about which models will be most helpful to support them when taking public health decisions, and modellers need to better understand the factors that will lead to successful model adoption and utilization. We present a three-stage framework for achieving these ends

    A pragmatic effectiveness study of 10-session cognitive behavioural therapy (CBT-T) for eating disorders: Targeting barriers to treatment provision

    Get PDF
    Objective Ten‐session cognitive behavioural therapy (CBT‐T) for transdiagnostic eating disorders targets several barriers to treatment, including cost, therapist expertise, and lengthy wait lists. Method We used a case series design to investigate the effectiveness of CBT‐T delivered by trainee psychologists in a postgraduate training clinic. Participants were randomly allocated to commence treatment either immediately or after a 4‐week waitlist period. CBT‐T was delivered to 52 patients, by six different trainees under supervision. Measures of eating disorder cognitions and behaviours, quality of life, and general psychopathology were examined in completer and intention‐to‐treat analyses using multilevel modelling. Last observation carried forward was applied for abstinence, remission, and good outcome analyses to aid comparison with prior studies. Results Significant improvements, associated with medium to large effect sizes, were found for eating disorder cognitions, behaviours quality of life, and negative affect from baseline to posttreatment, and at 1‐ and 3‐month follow‐up. Attrition (38.5%) was comparable with other treatment studies. Conclusion Results provide evidence for the effectiveness of CBT‐T delivered by trainee psychologists for transdiagnostic eating disorder patients, thus tackling some important barriers for treatment. Longer follow‐up, randomised controlled trial designs, and moderator analyses will provide more robust evidence about which patients do best with a shorter therapy

    Process Mining for Six Sigma

    Get PDF
    Process mining offers a set of techniques for gaining data-based insights into business processes from event logs. The literature acknowledges the potential benefits of using process mining techniques in Six Sigma-based process improvement initiatives. However, a guideline that is explicitly dedicated on how process mining can be systematically used in Six Sigma initiatives is lacking. To address this gap, the Process Mining for Six Sigma (PMSS) guideline has been developed to support organizations in systematically using process mining techniques aligned with the DMAIC (Define-Measure-Analyze-Improve-Control) model of Six Sigma. Following a design science research methodology, PMSS and its tool support have been developed iteratively in close collaboration with experts in Six Sigma and process mining, and evaluated by means of focus groups, demonstrations and interviews with industry experts. The results of the evaluations indicate that PMSS is useful as a guideline to support Six Sigma-based process improvement activities. It offers a structured guideline for practitioners by extending the DMAIC-based standard operating procedure. PMSS can help increasing the efficiency and effectiveness of Six Sigma-based process improving efforts. This work extends the body of knowledge in the fields of process mining and Six Sigma, and helps closing the gap between them. Hence, it contributes to the broad field of quality management

    Effectiveness of a web-based treatment program using intensive therapeutic support for female patients with bulimia nervosa, binge eating disorder and eating disorders not otherwise specified: study protocol of a randomized controlled trial

    Get PDF
    Background: Disordered eating behavior and body dissatisfaction affect a large proportion of the Dutch population and account for severe psychological, physical and social morbidity. Yet, the threshold for seeking professional care is still high. In the Netherlands, only 7.5% of patients with bulimia nervosa and 33% of patients with anorexia nervosa are treated within the mental health care system. Easily accessible and low-threshold interventions, therefore, are needed urgently. The internet has great potential to offer such interventions. The aim of this study is to determine whether a web-based treatment program for patients with eating disorders can improve eating disorder psychopathology among female patients with bulimia nervosa, binge eating disorder and eating disorders not otherwise specified. Methods/design: This randomized controlled trial will compare the outcomes of an experimental treatment group to a waiting list control group. In the web-based treatment program, participants will communicate personally and asynchronously with their therapists exclusively via the internet. The first part of the program will focus on analyzing eating attitudes and behaviors. In the second part of the program participants will learn how to change their attitudes and behaviors. Participants assigned to the waiting list control group will receive no-reply email messages once every two weeks during the waiting period of 15 weeks, after which they can start the program. The primary outcome measure is an improvement in eating disorder psychopathology as determined by the Eating Disorder Examination Questionnaire. Secondary outcomes include improvements in body image, physical and mental health, body weight, self-esteem, quality of life, and social contacts. In addition, the participants’ motivation for treatment and their acceptability of the program and the therapeutic alliance will be measured. The study will follow the recommendations in the CONSORT statement relating to designing and reporting on RCTs. Discussion: This study protocol presents the design of a RCT for evaluating the effectiveness of a web-based treatment program using intensive therapeutic support for female patients with bulimia nervosa, binge eating disorder and eating disorders not otherwise specified

    Pervasive Cryptic Epistasis in Molecular Evolution

    Get PDF
    The functional effects of most amino acid replacements accumulated during molecular evolution are unknown, because most are not observed naturally and the possible combinations are too numerous. We created 168 single mutations in wild-type Escherichia coli isopropymalate dehydrogenase (IMDH) that match the differences found in wild-type Pseudomonas aeruginosa IMDH. 104 mutant enzymes performed similarly to E. coli wild-type IMDH, one was functionally enhanced, and 63 were functionally compromised. The transition from E. coli IMDH, or an ancestral form, to the functional wild-type P. aeruginosa IMDH requires extensive epistasis to ameliorate the combined effects of the deleterious mutations. This result stands in marked contrast with a basic assumption of molecular phylogenetics, that sites in sequences evolve independently of each other. Residues that affect function are scattered haphazardly throughout the IMDH structure. We screened for compensatory mutations at three sites, all of which lie near the active site and all of which are among the least active mutants. No compensatory mutations were found at two sites indicating that a single site may engage in compound epistatic interactions. One complete and three partial compensatory mutations of the third site are remote and lie in a different domain. This demonstrates that epistatic interactions can occur between distant (>20Å) sites. Phylogenetic analysis shows that incompatible mutations were fixed in different lineages

    Polygenic prediction of educational attainment within and between families from genome-wide association analyses in 3 million individuals

    Get PDF
    We conduct a genome-wide association study (GWAS) of educational attainment (EA) in a sample of ~3 million individuals and identify 3,952 approximately uncorrelated genome-wide-significant single-nucleotide polymorphisms (SNPs). A genome-wide polygenic predictor, or polygenic index (PGI), explains 12-16% of EA variance and contributes to risk prediction for ten diseases. Direct effects (i.e., controlling for parental PGIs) explain roughly half the PGI's magnitude of association with EA and other phenotypes. The correlation between mate-pair PGIs is far too large to be consistent with phenotypic assortment alone, implying additional assortment on PGI-associated factors. In an additional GWAS of dominance deviations from the additive model, we identify no genome-wide-significant SNPs, and a separate X-chromosome additive GWAS identifies 57

    Steroid receptor coactivator-1 modulates the function of Pomc neurons and energy homeostasis

    Get PDF
    Hypothalamic neurons expressing the anorectic peptide Pro-opiomelanocortin (Pomc) regulate food intake and body weight. Here, we show that Steroid Receptor Coactivator-1 (SRC-1) interacts with a target of leptin receptor activation, phosphorylated STAT3, to potentiate Pomc transcription. Deletion of SRC-1 in Pomc neurons in mice attenuates their depolarization by leptin, decreases Pomc expression and increases food intake leading to high-fat diet-induced obesity. In humans, fifteen rare heterozygous variants in SRC-1 found in severely obese individuals impair leptin-mediated Pomc reporter activity in cells, whilst four variants found in non-obese controls do not. In a knock-in mouse model of a loss of function human variant (SRC-1L1376P), leptin-induced depolarization of Pomc neurons and Pomc expression are significantly reduced, and food intake and body weight are increased. In summary, we demonstrate that SRC-1 modulates the function of hypothalamic Pomc neurons, and suggest that targeting SRC-1 may represent a useful therapeutic strategy for weight loss.Peer reviewe

    Improved imputation of low-frequency and rare variants using the UK10K haplotype reference panel

    Get PDF
    Imputing genotypes from reference panels created by whole-genome sequencing (WGS) provides a cost-effective strategy for augmenting the single-nucleotide polymorphism (SNP) content of genome-wide arrays. The UK10K Cohorts project has generated a data set of 3,781 whole genomes sequenced at low depth (average 7x), aiming to exhaustively characterize genetic variation down to 0.1% minor allele frequency in the British population. Here we demonstrate the value of this resource for improving imputation accuracy at rare and low-frequency variants in both a UK and an Italian population. We show that large increases in imputation accuracy can be achieved by re-phasing WGS reference panels after initial genotype calling. We also present a method for combining WGS panels to improve variant coverage and downstream imputation accuracy, which we illustrate by integrating 7,562 WGS haplotypes from the UK10K project with 2,184 haplotypes from the 1000 Genomes Project. Finally, we introduce a novel approximation that maintains speed without sacrificing imputation accuracy for rare variants

    Genetic mechanisms of critical illness in COVID-19.

    Get PDF
    Host-mediated lung inflammation is present1, and drives mortality2, in the critical illness caused by coronavirus disease 2019 (COVID-19). Host genetic variants associated with critical illness may identify mechanistic targets for therapeutic development3. Here we report the results of the GenOMICC (Genetics Of Mortality In Critical Care) genome-wide association study in 2,244 critically ill patients with COVID-19 from 208 UK intensive care units. We have identified and replicated the following new genome-wide significant associations: on chromosome 12q24.13 (rs10735079, P = 1.65 × 10-8) in a gene cluster that encodes antiviral restriction enzyme activators (OAS1, OAS2 and OAS3); on chromosome 19p13.2 (rs74956615, P = 2.3 × 10-8) near the gene that encodes tyrosine kinase 2 (TYK2); on chromosome 19p13.3 (rs2109069, P = 3.98 ×  10-12) within the gene that encodes dipeptidyl peptidase 9 (DPP9); and on chromosome 21q22.1 (rs2236757, P = 4.99 × 10-8) in the interferon receptor gene IFNAR2. We identified potential targets for repurposing of licensed medications: using Mendelian randomization, we found evidence that low expression of IFNAR2, or high expression of TYK2, are associated with life-threatening disease; and transcriptome-wide association in lung tissue revealed that high expression of the monocyte-macrophage chemotactic receptor CCR2 is associated with severe COVID-19. Our results identify robust genetic signals relating to key host antiviral defence mechanisms and mediators of inflammatory organ damage in COVID-19. Both mechanisms may be amenable to targeted treatment with existing drugs. However, large-scale randomized clinical trials will be essential before any change to clinical practice
    • 

    corecore