A Metabolomics approach for the diagnosis Of SecondAry InfeCtions in COVID-19 (MOSAIC): a study protocol

Background Critically ill patients with COVID-19 are at an increased risk of developing secondary bacterial infections. These are both difficult to diagnose and are associated with an increased mortality. Metabolomics may aid clinicians in diagnosing secondary bacterial infections in COVID-19 through identification and quantification of disease specific biomarkers, with the aim of identifying underlying causative microorganisms and directing antimicrobial therapy. Methods This is a multi-centre prospective diagnostic observational study. Patients with COVID-19 will be recruited from critical care units in three Scottish hospitals. Three serial blood samples will be taken from patients, and an additional sample taken if a patient shows clinical or microbiological evidence of secondary infection. Samples will be analysed using LC–MS and subjected to bioinformatic processing and statistical analysis to explore the metabolite changes associated with bacterial infections in COVID-19 patients. Comparisons of the data sets will be made with standard microbiological and biochemical methods of diagnosing infection. Discussion Metabolomics analyses may provide additional strategies for identifying secondary infections, which might permit faster initiation of specific tailored antimicrobial therapy to critically ill patients with COVID-19.

Use of Site-Specific Data for Modeling Selenium Bioaccumulation by Terrestrial Animals

We developed a bioaccumulation model from an extensive set of monitoring data to predict selenium (Se) concentrations in biota within a terrestrial system (Kesterson Reservoir, CA). The model uses water-extractable Se concentrations in soil to estimate the expected range of mean Se concentrations in biota at Kesterson for future scenarios. Biological monitoring data collected at Kesterson Reservoir from 1988 to 1994 were used to parameterize the initial model. The model was tested and updated with additional sample results from 1995 through 2001 biological monitoring and validated and calibrated using Se concentrations from sampling conducted in 2004 and 2006. Minor adjustments were made to the model based on each additional year’s results and the model was used in 2014 to assess whether there were continuing threats to wildlife at Kesterson. The model predicts Se concentrations in small mammals, bird blood, and bird eggs in common species found at Kesterson. This model was used for the final assessment of Kesterson in 2014 and performed well, but there was variability in results due to differences in individual diets and feeding ranges of animals. In the comparisons of 2014 predicted to measured Se, only whole-body mice, deer mice (Peromyscus maniculatus), and kestrel blood were significantly different. The trophic transfer factors and regression equations should be applicable to other Se-contaminated sites; adjusting weighting factors based on diet and range allows the model to be adapted and used at other sites.

Integrating Sample Similarities into Latent Class Analysis: A Tree-Structured Shrinkage Approach

SummaryThis paper is concerned with using multivariate binary observations to estimate the proportions of unobserved classes with scientific meanings. We focus on the setting where additional information about sample similarities is available and represented by a rooted weighted tree. Every leaf in the given tree contains multiple independent samples. Shorter distances over the tree between the leaves indicate higher similarity. We propose a novel data integrative extension to classical latent class models (LCMs) with tree-structured shrinkage. The proposed approach enables 1) borrowing of information across leaves, 2) estimating data-driven leaf groups with distinct vectors of class proportions, and 3) individual-level probabilistic class assignment given the observed multivariate binary measurements. We derive and implement a scalable posterior inference algorithm in a variational Bayes framework. Extensive simulations show more accurate estimation of class proportions than alternatives that suboptimally use the additional sample similarity information. A zoonotic infectious disease application is used to illustrate the proposed approach. The paper concludes by a brief discussion on model limitations and extensions.

On the radial abundance gradients of nitrogen and oxygen in the inner Galactic disc

ABSTRACT We present optical spectra of nine Galactic H ii regions observed with the 10.4 m Gran Telescopio Canarias telescope and located at Galactocentric distances (RG) from 4 to 8 kpc. The distances of the objects have been revised using Gaia DR2 parallaxes. We determine the electron temperature for all the nebulae, which allows a precise computation of their ionic abundances. We have included published data of an additional sample of Galactic H ii regions, providing a final data set of 42 objects. The shape of the radial gradients of O/H and N/H is linear and constant, discarding any substantial change of the slope, at least for RG between 4 and 17 kpc. The small dispersion of the O/H and N/H values with respect to the computed gradients imply the absence of significant azimuthal variations of the chemical abundances, at least in the quadrant covered by our observations. We find an almost flat N/O versus O/H diagram relation. This result is not observed in other nearby spiral galaxies except M31. Finally, we compare our computed gradients with those obtained using far-infrared (FIR) spectra. We confirm the significant offset in the N/O distribution between the optical and FIR observations. Possible explanations involve ionization correction factors and the strong dependence on density of the abundance determinations based on FIR lines.

Perceptions of HR: an analysis of millennial and postmillennial insights

Purpose The purpose of this study is to examine the perceptions of the human resources (HR) function from millennials and postmillennials who are either just finishing college or already in the early stages of their careers. Previous works have often revealed negative stereotypes toward HR, and this study serves to discover whether these perceptions are changing. Further, the study aims to address the origins of and reasoning behind these new perceptions. Design/methodology/approach A two-study survey research design using a sample of 106 college of business students (Study 1) and an additional sample of 135 former business students who have graduated since 2011 (Study 2) is used. Findings The results demonstrate that perceptions of HR are changing and quite positive, with the majority of these perceptions originating from personal experiences. In fact, the vast majority of respondents not only felt positive about HR but also like and trust their HR representatives. Originality/value Results also suggest that there may be a disconnect between perceptions of the HR function and its actual purpose, suggesting that HR professionals need to better educate others about their important role as a strategic business partner.

A Non‐Enzymatic Disposable Electrochemical Sensor Based on Surface-Modified Screen-Printed Electrodes CuO-IL/rGO Nanocomposite for Single-Step Determination of Glucose in Human Urine and Electrolyte Drink

A non‐enzymatic disposable electrochemical sensor coupled with an automated sample pretreatment paper-based device was developed to avoid an additional sample preparation step for glucose determination in human urine and electrolyte...

The genera Helvella and Dissingia (Ascomycota: Pezizomycetes) in Europe – Notes on species from Spain

Phylogenetic analyses of 115 newly collected Helvella specimens from Spain using three genetic markers [heat shock protein 90 (hsp), RNA polymerase II second largest subunit (rpb2) and the nuclear large subunit ribosomal DNA (LSU)] confirm the assignment of the Spanish collections to one Dissingia and 30 Helvella species. The analyses were supplemented with an additional sample of 65 Spanish and extralimital Helvella specimens from the fungaria of Oslo (O), Trondheim (TRH), Copenhagen (C), Uppsala (UPS), Stockholm (S) and Venice (MCVE). Nine species are described as new, i.e. Helvella fuscolacunosa, H. hispanica, H. iberica, H. inexpectata, H. neopallescens, H. phlebophoroides, H. poculiformis, H. retinervis, and H. terricola. We present photographs of a selection of fresh specimens and provide descriptions of all species of this diverse South European Mediterranean element of the genera in Europe.

One-Stage Multiple Comparisons with the Control for Exponential Median Lifetimes under Heteroscedasticity

When the additional sample for the second stage may not be available, one-stage multiple comparisons for exponential median lifetimes with the control under heteroscedasticity including one-sided and two-sided confidence intervals are proposed in this paper since the median is a more robust measure of central tendency compared to the mean. These intervals can be used to identify treatment populations that are better than the control or worse than the control in terms of median lifetimes in agriculture, stock market, pharmaceutical industries. Tables of critical values are obtained for practical use. An example of comparing the survival days for four categories of lung cancer in a standard chemotherapeutic agent is given to demonstrate the proposed procedures.

Expression of miR-135b in Psoriatic Skin and Its Association with Disease Improvement

miRNAs have been associated with psoriasis since just over a decade. However, we are far from a complete understanding of their role during the development of this disease. Our objective was to characterize the cutaneous expression of miRNAs not previously described in psoriasis, the changes induced following the treatment with biologicals and their association with disease improvement. Next generation sequencing was performed from five skin samples from psoriasis patients (lesional and non-lesional skin) and five controls, and from this cohort, 12 microRNAs were selected to be analyzed in skin samples from 44 patients with plaque psoriasis. In 15 patients, an additional sample was obtained after three months of biological treatment. MiR-9-5p, miR-133a-3p and miR-375 were downregulated in the lesional skin of psoriasis patients. After treatment, expression of miR-133a-3p, miR-375, miR-378a and miR-135b in residual lesions returned towards the levels observed in non-lesional skin. The decrease in miR-135b levels after treatment with biologics was associated with both the improvement of patients evaluated through Psoriasis Area and Severity Index score and the decrease in local inflammatory response. Moreover, basal expression of miR-135b along with age was associated with the improvement of psoriasis, suggesting its possible usefulness as a prognostic biomarker.

Estimating Effect of Additional Sample on Uncertainty Reduction in Reliability Analysis Using Gaussian Process

An approach is proposed to quantify the uncertainty in probability of failure using a Gaussian process (GP) and to estimate uncertainty change before actually adding samples to GP. The approach estimates the coefficient of variation (CV) of failure probability due to prediction variance of GP. The CV is estimated using single-loop Monte Carlo simulation (MCS), which integrates the probabilistic classification function while replacing expensive multi-loop MCS. The methodology ensures a conservative estimate of CV, in order to compensate for sampling uncertainty in MCS. Uncertainty change is estimated by adding a virtual sample from the current GP and calculating the change in CV, which is called expected uncertainty change (EUC). The proposed method can help adaptive sampling schemes to determine when to stop before adding a sample. In numerical examples, the proposed method is used in conjunction with the efficient local reliability analysis to calculate the reliability of analytical function as well as the battery drop test simulation. It is shown that the EUC converges to the true uncertainty change as the model becomes accurate.