834 research outputs found

    Tunnel diode circuit used as nanosecond-range time marker

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    Simple tunnel diode time marker circuit determines the time at which an event occurs in a scintillation crystal. It is capable of triggering at voltages as low as the noise level of a 10-stage PM tube

    Corporate Dividend Policies during the COVID-19 Pandemic

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    : In this paper, we examine the changes in corporate dividend policies during the COVID-19 shock. For empirical analysis, we employ annual data of 360 companies from the Pakistan Stock Exchange over the period 2015–2020. Using descriptive analysis and Logit regression models, we find that firms were more likely to either omit or reduce dividend payments during the pandemic year of 2020 as compared to the trends in pre-COVID-19 years of 2015–2019. Further, firms with higher profitability, asset turnover and size were less likely to opt for dividend omissions. On the contrary, dividend omissions were more likely among firms with higher debt ratios. The findings of this study helps to understand firm dividend policies during crisis periods

    Sensing the heat: Climate change vulnerability and foreign direct investment inflows

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    We investigate whether climate change vulnerability determines foreign direct investment (FDI) inflows. We reason that multinational firms foresee a higher climate change vulnerability of host-country a locational disadvantage while making FDI allocation decisions. Utilizing annual data from 152 countries spanning the period 1996–2019 and employing the panel pooled ordinary least square regressions, we evidence that FDI inflows are lower in countries more vulnerable to climate change. We also observe that FDI inflows are only sensitive to climate-related risks in high- and middle-income countries, but not in low-income countries where the market size is a primary driver of FDI inflows. Moreover, we also find that host countries may weaken the adverse effects of climate change vulnerability on FDI inflows by strengthening the economic, institutional, and social environment

    The efficacy and safety of pulse vs. continuous therapy for dermatophyte toenail onychomycosis

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    Background Onychomycosis is a chronic, fungal infection of the nails. Complete cure remains challenging, but oral antifungal medications have been successful in managing the fungus for a significant proportion of patients. Treatment with these drugs can be continuous or intermittent, albeit the evidence on their relative efficacies remains unclear. Objective To determine the relative effectiveness and safety of pulse versus continuous administration, of three common oral therapies for dermatophyte onychomycosis, by conducting multiple‐treatment meta‐analysis. Methods This systematic review and network meta‐analysis compared the efficacy (as per mycological cure) and adverse event rates of three oral antifungal medications in the treatment of dermatophyte toenail onychomycosis, namely terbinafine, itraconazole and fluconazole. A total of 30 studies were included in the systematic review, while 22 were included in the network meta‐analysis. Results The likelihood of mycological cure was not significantly different between continuous and pulse regimens for each of terbinafine and itraconazole. Use of continuous terbinafine for 24 weeks – but not 12 weeks – was significantly more likely to result in mycological cure than continuous itraconazole for 12 weeks or weekly fluconazole for 9–12 months. Rank probabilities demonstrated that 24‐week continuous treatment of terbinafine was the most effective. There were no significant differences in the likelihood of adverse events between any continuous and pulse regimens of terbinafine, itraconazole and fluconazole. Drug treatments were similar to placebo in terms of their likelihood of producing adverse events. Conclusion More knowledge about the fungal life cycle and drugs’ pharmacokinetics in nail and plasma could further explain the relative efficacy and safety of the pulse and continuous treatment regimens. Our results indicate that in the treatment of dermatophyte toenail onychomycosis, the continuous and pulse regimens for terbinafine and itraconazole have similar efficacies and rates of adverse events

    Towards precision medicine for hypertension: a review of genomic, epigenomic, and microbiomic effects on blood pressure in experimental rat models and humans

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    Compelling evidence for the inherited nature of essential hypertension has led to extensive research in rats and humans. Rats have served as the primary model for research on the genetics of hypertension resulting in identification of genomic regions that are causally associated with hypertension. In more recent times, genome-wide studies in humans have also begun to improve our understanding of the inheritance of polygenic forms of hypertension. Based on the chronological progression of research into the genetics of hypertension as the "structural backbone," this review catalogs and discusses the rat and human genetic elements mapped and implicated in blood pressure regulation. Furthermore, the knowledge gained from these genetic studies that provide evidence to suggest that much of the genetic influence on hypertension residing within noncoding elements of our DNA and operating through pervasive epistasis or gene-gene interactions is highlighted. Lastly, perspectives on current thinking that the more complex "triad" of the genome, epigenome, and the microbiome operating to influence the inheritance of hypertension, is documented. Overall, the collective knowledge gained from rats and humans is disappointing in the sense that major hypertension-causing genes as targets for clinical management of essential hypertension may not be a clinical reality. On the other hand, the realization that the polygenic nature of hypertension prevents any single locus from being a relevant clinical target for all humans directs future studies on the genetics of hypertension towards an individualized genomic approach

    Ordinal-Level Phylogenomics of the Arthropod Class Diplopoda (Millipedes) Based on an Analysis of 221 Nuclear Protein-Coding Loci Generated Using Next-Generation Sequence Analyses

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    Background The ancient and diverse, yet understudied arthropod class Diplopoda, the millipedes, has a muddled taxonomic history. Despite having a cosmopolitan distribution and a number of unique and interesting characteristics, the group has received relatively little attention; interest in millipede systematics is low compared to taxa of comparable diversity. The existing classification of the group comprises 16 orders. Past attempts to reconstruct millipede phylogenies have suffered from a paucity of characters and included too few taxa to confidently resolve relationships and make formal nomenclatural changes. Herein, we reconstruct an ordinal-level phylogeny for the class Diplopoda using the largest character set ever assembled for the group. Methods Transcriptomic sequences were obtained from exemplar taxa representing much of the diversity of millipede orders using second-generation (i.e., next-generation or high-throughput) sequencing. These data were subject to rigorous orthology selection and phylogenetic dataset optimization and then used to reconstruct phylogenies employing Bayesian inference and maximum likelihood optimality criteria. Ancestral reconstructions of sperm transfer appendage development (gonopods), presence of lateral defense secretion pores (ozopores), and presence of spinnerets were considered. The timings of major millipede lineage divergence points were estimated. Results The resulting phylogeny differed from the existing classifications in a number of fundamental ways. Our phylogeny includes a grouping that has never been described (Juliformia+Merocheta+Stemmiulida), and the ancestral reconstructions suggest caution with respect to using spinnerets as a unifying characteristic for the Nematophora. Our results are shown to have significantly stronger support than previous hypotheses given our data. Our efforts represent the first step toward obtaining a well-supported and robust phylogeny of the Diplopoda that can be used to answer many questions concerning the evolution of this ancient and diverse animal group

    A population study comparing screening performance of prototypes for depression and anxiety with standard scales

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    <p>Abstract</p> <p>Background</p> <p>Screening instruments for mental disorders need to be short, engaging, and valid. Current screening instruments are usually questionnaire-based and may be opaque to the user. A prototype approach where individuals identify with a description of an individual with typical symptoms of depression, anxiety, social phobia or panic may be a shorter, faster and more acceptable method for screening. The aim of the study was to evaluate the accuracy of four new prototype screeners for predicting depression and anxiety disorders and to compare their performance with existing scales.</p> <p>Methods</p> <p>Short and ultra-short prototypes were developed for Major Depressive Disorder (MDD), Generalised Anxiety Disorder (GAD), Panic Disorder (PD) and Social Phobia (SP). Prototypes were compared to typical short and ultra-short self-report screening scales, such as the Centre for Epidemiology Scale, CES-D and the GAD-7, and their short forms. The Mini International Neuropsychiatric Interview (MINI) version 6 <abbrgrp><abbr bid="B1">1</abbr></abbrgrp> was used as the gold standard for obtaining clinical criteria through a telephone interview. From a population sample, 225 individuals who endorsed a prototype and 101 who did not were administered the MINI. Receiver operating characteristic (ROC) curves were plotted for the short and ultra short prototypes and for the short and ultra short screening scales.</p> <p>Results</p> <p>The study found that the rates of endorsement of the prototypes were commensurate with prevalence estimates. The short-form and ultra short scales outperformed the short and ultra short prototypes for every disorder except GAD, where the GAD prototype outperformed the GAD 7.</p> <p>Conclusions</p> <p>The findings suggest that people may be able to self-identify generalised anxiety more accurately than depression based on a description of a prototypical case. However, levels of identification were lower than expected. Considerable benefits from this method of screening may ensue if our prototypes can be improved for Major Depressive Disorder, Social Phobia and Panic Disorder.</p
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