High-throughput UHPLC-MS to screen metabolites in feces for gut metabolic health

(1) Background: Feces are the product of our diets and have been linked to diseases of the gut, including Crohn's disease and metabolic diseases such as diabetes. For screening metabolites in heterogeneous samples such as feces, it is necessary to use fast and reproducible analytical methods that maximize metabolite detection. (2) Methods: As sample preparation is crucial to obtain high quality data in MS-based clinical metabolomics, we developed a novel, efficient and robust method for preparing fecal samples for analysis with a focus in reducing aliquoting and detecting both polar and non-polar metabolites. Fecal samples (n= 475) from patients with alcohol-related liver disease and healthy controls were prepared according to the proposed method and analyzed in an UHPLC-QQQ targeted platform in order to obtain a quantitative profile of compounds that impact liver-gut axis metabolism. (3) Results: MS analyses of the prepared fecal samples have shown reproducibility and coverage of n=28 metabolites, mostly comprising bile acids and amino acids. We report metabolite-wise relative standard deviation (RSD) in quality control samples, inter-day repeatability, LOD, LOQ and range of linearity. The average concentrations for 135 healthy participants are reported here for clinical applications. (4) Conclusions: our high-throughput method provides an efficient tool for investigating gut-liver axis metabolism in liver-related diseases using a noninvasive collected sample.

Improving Calibration Strategy for LIBS Heavy Metals Analysis in Agriculture Applications

A new calibration procedure, known as mapping conditional-calibration laser-induced breakdown spectroscopy (LIBS), has been suggested to improve analysis results for heterogeneous samples. The procedure is based on LIBS elemental mapping, followed by signal conditioning in every sampling spot to skip signal outliers, then by finalizing the calibration curve construction. The suggested mapping conditional calibration procedure was verified for zinc analysis in soybean grist samples. The laser parameters correspond to those of the hand-held LIBS instrument in order to estimate the influence of sample surface heterogeneity under on-site analysis conditions. The laser spot (60 μm) was equal to or smaller than the typical size of grist particles (40–500 μm) but laser crater dimensions were significantly greater and varied widely (150–450 μm). The LIBS mapping of different spectral signals (atomic and ionic lines for major and minor components) was achieved. Elemental maps were normalized to achieve signal maps that were conditionally spotted to skip signal outliers. It was demonstrated that the suggested mapping conditional-calibration LIBS provided 15 ppm RMSECV for zinc determination in heterogeneous samples, which is typical for agricultural products.

BIOAVAILABLE STRONTIUM ISOTOPE BASELINE FOR THE NOVOTEMIRSKIY BRONZE AGE MINE

Для оценки мобильности и идентификации происхождения древних популяций требуется проводить сравнение их изотопных отношений 87Sr/86Sr с локальной базовой (фоновой) линией биодоступного стронция, характерной для каждого конкретного местонахождения или потенциального района происхождения индивида или артефакта. В данной работе на примере древнего рудника Новотемирский (Южный Урал) эпохи бронзы проведена оценка такой базовой линии. Изотопные отношения 87Sr/86Sr определены в поверхностной и подземной воде, коренной породе (серпентинит), глине из стенки шахты, кости светлого хоря, а также в траве и раковине двустворки с берега озера. Наименьшим разбросом изотопных отношений стронция друг относительно друга обладают поверхностная и подземная вода, раковина и трава, что позволяет использовать их для определения объединенной базовой линии биодоступного стронция. Мульти-прокси (поверхностная и подземная вода, травы и раковина двустворки) локальная базовая линия биодоступного стронция для района древнего рудника Новотемирский (Южный Урал) может быть представлена в виде диапазона 0,7096 ± 0,0003 (2σ, n = 5). To assess the mobility and provenance of ancient populations, it is necessary to compare their 87Sr/86Sr isotopic ratios with the local bioavailable strontium baseline (background), characteristic of each specific location or potential provenance region of an individual or artifact. Its definition requires a comprehensive approach to the analysis of heterogeneous samples («proxies») characterizing the ecosystem of the archaeological site under study, the identification of the most suitable proxies, as well as the unification and standardization of the sampling and analytic protocols. A pilot study is presented devoted the definition of the local range of bioavailable strontium by the example of the Novotemirskiy Bronze Age mine (Southern Urals). 87Sr/86Sr isotope ratios were determined in surface and underground water, bedrock (serpentinite), clay from the mine wall, and steppe polecat's bone, as well as in grass and a bivalve shell from the lake. The lowest range of strontium isotope ratios relative to each other is characteristic of surface and groundwater, shell and grass, which allows them to be used to determine the combined baseline of bioavailable strontium. Multi-proxy (surface and underground water, grass and a bivalve shell) local bioavailable strontium baseline for the Novotemirskiy ancient mine (Southern Urals) is 0,7096 ± 0,0003 (2σ, n = 5).

The day-of-invitation effect on participation in web-based studies

Several methods have been proposed to promote participation in web-based research. Here, we examine a technique that is available at no cost: Inviting respondents per e-mail on a particular day of the week. We base our reasoning on such a day-of-invitation effect upon theories on variations in mood and work performance over the week. We conducted five experiments with large and heterogeneous samples to find out whether such effects apply for response rate (i.e., visiting the first page of a study) and retention rate (i.e., completing the study) in web-based studies. We found evidence of a small but significant day-of-invitation effect. Response rate is high at the beginning of the workweek and falls to a low on Friday. Exploratory analyses showed that this decline is higher for employed (vs. nonemployed) persons. Effects on retention rate appear to follow a less straightforward pattern. We discuss possible mechanisms that might account for the day-of-invitation effect and recommend inviting participants on Monday or Tuesday.

Measuring Six Facets of Curiosity in Two Cultures: A Validation of the Theory of Multi-Facetted Curiosity in Germany and the UK

The five-dimensional curiosity-scale revised by Kashdan et al. (2020) is the most comprehensive inventory of curiosity. We provide the first validation of this newly proposed structure of curiosity in cultures (Germany and UK) other than the United States. In the process, we develop the first adaptation of this inventory in another language, namely German (6DNS). We also provide the first measurement invariance analyses for this curiosity inventory across two cultures and the socio-demographics age, sex, and education. We use two diverse quota samples from Germany (N = 486) and the UK (N = 483). In both countries, we investigate the single facets' reliability, factorial validity, and convergent and divergent validity with a large set of individual-differences constructs. Findings demonstrate that both the new German version (6DNS) and the English version (5DCR) show psychometric properties similar to the original findings by Kashdan et al. (2020). Moreover, all facets of the inventory reach at least scalar invariance across cultures, sex, education, and largely across age. The findings support the six-faceted theory of curiosity and show that 5DCR/6DNS is the first curiosity inventory that allows an assessment of a multifaceted curiosity across cultures and for heterogeneous samples.

Moral sensitivity in business: A revised measure

In order to manage ethical challenges in organizations and the workplace, moral sensitivity (MS)—the ability to identify and ascribe importance to moral issues when they arise in the workplace—is seen as the key prerequisite by researchers and professionals. However, despite the importance of MS, satisfactory reliable and valid measures to assess this competence are to date lacking. The present research tests the psychometric qualities of a revised MS measure for the business domain (R-MSB) that is designed to assess individual differences in moral and business-related value sensitivity. We present three different analyses with two heterogeneous samples of Swiss and German employees (total N = 1168). The first two studies provide good evidence of the measures’ factorial structure, its construct, and criteria-related validity. The third study examines how affective and empathic responses are associated with MS and business sensitivity (BS). The results support the view that empathic responsiveness enhances MS. The instrument’s theoretical and practical strengths, limitations, and avenues for future research are discussed.

Fluorine Depth Profiling Based on the 19F(p,p’g)19F Excitation Function

Ion beam analysis of fluorine has applications in research on teeth and bones, materials science, geochemistry and archaeometry. A novel PIGE (Particle Induced Gamma-ray Emission) standard free methodology for fluorine content determination for in-depth heterogeneous samples based on the excitation function of the 19F(p,p’γ)19F nuclear reaction is presented. New precise cross section measurements of this reaction in the proton energy range 2.1 to 4.1 MeV have been performed. In addition, the ERYA-Profiling code, a computer program specially developed for PIGE analysis of in-depth heterogeneous samples, employed this new excitation function in a case study where different fluorine simulated depth profiles probed the capability of insight into fluorine distributions in a given sample, showing the potential of PIGE analysis.