561975 research outputs found
Sort by
Macromolecular crystallography at the Philipps University Marburg (MarBAG)
No full textThe MarBAG, based at Philipps-University Marburg and the Max-Planck-Institute for Terrestrial Microbiology in Marburg, Germany, employs X-ray crystallography to elucidate the fundamental mechanisms underlying the synthesis, assembly, and function of macromolecular machines and cellular structures. This research encompasses critical biological processes, including CO2 fixation pathways, flagellar biosynthesis, CRISPR-Cas systems, and phage-bacteria interactions. Additionally, our investigations extend to plant-pathogen interactions and the role of nucleotide-derived signaling molecules in cellular stress physiology and organization of bacteria and higher organisms.To enhance our structural characterization of macromolecular complexes that are challenging to crystallize, we have recently installed a 200 keV cryo-electron microscope at UMR. This advanced instrumentation enables routine screening and quality assessment of samples for cryoelectron microscopy
Known unknowns and the osteological paradox: Why bioarchaeology needs agent-based models
No full textObjective: This paper demonstrates computational modeling's value as a tool for mapping the impact of hidden variables and evaluating the accuracy of statistical methods in bioarchaeology. Materials: As a working example, this paper presents an agent-based model of a 1,000-person cohort of individuals who can form an unspecified skeletal lesion at any age between birth and ten years and enter a simulated cemetery at the end of their lives. Skeletal lesions either have no effect on mortality risk (scenario 1) or are associated with doubled mortality risk (scenario 2). Methods: The agent-based model simulates data on individual age at death and lesion status. Kaplan-Meier survival analysis is run on each simulated dataset, comparing survival estimates for individuals with and without lesions. Results: Survival analyses underestimate the true value of lesion-associated mortality risk in early life in scenario 2 and produce a false lesion-associated survival advantage under the null conditions of scenario 1. Conclusions: Researchers should account for the ages of a skeletal lesion's developmental window, where known, when assessing lesion-associated mortality. Survival analyses return accurate results when they exclude individuals in the ages of active lesion formation. Significance: Modeling experiments can identify which archaeologically unmeasurable variables have the greatest impact on estimates of population health and outline the ways in which they bias estimates of past health from the skeletal record. Limitations: The only limits on modeling are limits of imagination and common sense. Suggestions for future research: Many other archaeologically hidden variables remain to be explored with this approach
Verification of a hybrid kinetic-gyrokinetic model using the advanced semi-Lagrange code ssV
No full textThe dispositional basis of deviance: a multivariate approach to crime and other deviant acts
No full textWhy some people engage in criminal and other forms of deviant behavior, whereas others do not, has long been a question of interest in the social and behavioral sciences. In this study, we examine the role of personality differences in accounting for different forms of deviance. Using data from a large and demographically diverse German sample (N = 2,364), we investigated associations between 74 personality traits and five self-reported indicators of deviant behavior. We analyzed these relations at both the zero-order and multivariate level using regularized regression models to identify which personality traits predict deviant behavior most strongly and uniquely so, that is, above and beyond other traits. Personality explained a substantial proportion of variance in all forms of deviance considered, and these associations were not attributable to methodological artifacts or confounding influences of age or gender. Supporting our pre-registered hypothesis, traits related to dispositional morality or short-term mindsets were particularly powerful predictors. Taken together, our findings provide the most comprehensive overview to date of personality-deviance associations, offer a parsimonious account of individual differences in self-reported deviance, derive concrete guidelines for trait selection in future research, and introduce a ShinyApp that can guide theorizing and study design
