University of Cologne

About: University of Cologne is a education organization based out in Cologne, Germany. It is known for research contribution in the topics: Population & Gene. The organization has 32050 authors who have published 66350 publications receiving 2210092 citations. The organization is also known as: Universität zu Köln & Universitatis Coloniensis.

Many analysts, one dataset: Making transparent how variations in analytical choices affect results

Abstract: Twenty-nine teams involving 61 analysts used the same data set to address the same research question: whether soccer referees are more likely to give red cards to dark-skin-toned players than to light-skin-toned players. Analytic approaches varied widely across the teams, and the estimated effect sizes ranged from 0.89 to 2.93 (Mdn = 1.31) in odds-ratio units. Twenty teams (69%) found a statistically significant positive effect, and 9 teams (31%) did not observe a significant relationship. Overall, the 29 different analyses used 21 unique combinations of covariates. Neither analysts’ prior beliefs about the effect of interest nor their level of expertise readily explained the variation in the outcomes of the analyses. Peer ratings of the quality of the analyses also did not account for the variability. These findings suggest that significant variation in the results of analyses of complex data may be difficult to avoid, even by experts with honest intentions. Crowdsourcing data analysis, a strategy in which numerous research teams are recruited to simultaneously investigate the same research question, makes transparent how defensible, yet subjective, analytic choices influence research results.

Spin State Transition in LaCoO3 Studied Using Soft X-ray Absorption Spectroscopy and Magnetic Circular Dichroism

Abstract: Using soft x-ray absorption spectroscopy and magnetic circular dichroism at the Co-L(2,3) edge, we reveal that the spin state transition in LaCoO3 can be well described by a low-spin ground state and a triply degenerate high-spin first excited state From the temperature dependence of the spectral line shapes, we find that LaCoO3 at finite temperatures is an inhomogeneous mixed-spin state system It is crucial that the magnetic circular dichroism signal in the paramagnetic state carries a large orbital momentum This directly shows that the currently accepted low- or intermediate-spin picture is at variance Parameters derived from these spectroscopies fully explain existing magnetic susceptibility, electron spin resonance, and inelastic neutron data

Targeted disruption of µ chain membrane exon causes loss of heavy-chain allelic exclusion

Abstract: BURNET'S clonal selection theory1 suggests that each B lymphocyte is committed to a single antibody specificity. This is achieved by a programme of somatic rearrangements of the gene segments encoding antibody variable (V) regions, in the course of B-cell development2,3. Evidence from immunoglobulin-transgenic mice and immunoglobulin-gene-transfected transformed pre-B cells suggests that the membrane form of the immunoglobulin heavy (H) chain of class µ (µm), expressed from a rearranged H-chain (IgH) locus, may signal allelic exclusion of the homologous IgH locus in the cell4–6 and initiation of light (L)-chain gene rearrangement in the Ig/c loci6. We report here that targeted disruption of the membrane exon of the µ chain indeed results in the loss of H-chain allelic exclusion. But, some K chain gene rearrangement is still observed in the absence of µm expression.

Blinks and saccades as indicators of fatigue in sleepiness warnings: looking tired?

Abstract: The present study examines changes in a variety of oculomotoric variables as a function of increasing sleepiness in 129 participants, who have been passed through a broad range of subjective alertness. Up to now, spontaneous eye blinks are the most promising biosignal for in-car sleepiness warnings. Reviewing the current literature on eye movements and fatigue, experimental data are provided including additional indicative oculomotoric parameters; inter-individual differences in the experiments were also assessed. Here, self-rated alertness decreased over six steps on average and proved itself a reliable measurement. Regarding oculomotoric parameters, blink duration, delay of lid reopening, blink interval and standardised lid closure speed were identified as the best indicators of subjective as well as objective sleepiness. Saccadic parameters and fixation durations also showed specific changes with increasing sleepiness. Substantial inter-individual differences in all of these variables were illustrated. Oculomotoric parameters were linked to three different components of sleepiness while driving: a) deactivation; b) decreasing attention, resulting in disinhibition of spontaneous blinks and reflexive saccades; c) increasing attempts of self-activation. Finally, implications for the development of drowsiness detection devices were discussed.