Establishing multi-perspective instruments in early education during COVID-19: measuring the implementation of protective measures and the subjective level of information about pandemic-related regulations

This article describes the context, development, objectives, and content of three instruments. They stem from two questionnaires, used in the ERiK-Surveys 2020 and the Corona-KiTa-Study (CKS), two multi-perspective surveys which were developed by the German Youth Institute, to measure quality as well as challenges and solutions of the Corona pandemic in early childhood education and care (ECEC). The three instruments focus on (1) childcare center directors' subjective level of information about pandemic-related regulations in the ERiK questionnaire and the extent of implementation of (2) hygiene and (3) protective measures in ECEC in the CKS questionnaire. First analyses suggest good performance and quality of the instruments. Further analyses (e.g., regarding validity and reliability) will be carried out. The instruments seem to be promising for future research, for example regarding medical questions in the field of ECEC

The more concentrated, the better represented? The geographical concentration of immigrants and their descriptive representation in the German mixed-member system

<p>Supplemental material, IPS796263_supplemental_data for The more concentrated, the better represented? The geographical concentration of immigrants and their descriptive representation in the German mixed-member system by Lucas Geese and Diana Schacht in International Political Science Review</p

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals &lt;1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data