University of Konstanz
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Cut off from new competition: Threat of entry and quality of primary care
No full textWe study how the threat of entry affects service quantity and quality of general practitioners (GPs). We leverage Germany’s needs-based primary care planning system, in which the likelihood of new GPs reduces by 20 percentage points when primary care coverage exceeds a cut-off. We compile novel data covering all German primary care regions and up to 30,000 GP-level observations from 2014 to 2019. Reduced threat of entry lowers patient satisfaction for incumbent GPs without nearby competitors but not in areas with competitors. We find no effects on working hours or quality measures at the regional level including hospitalizations and mortality.publishe
The key role of base rates : systematic review and meta-analysis of the predictive value of four risk assessment instruments
No full textAIMS OF THE STUDY: Many countries have seen a decline in recidivism rates over the past decades. These base rates are pertinent information for assessing the recidivism risk of offenders. They provide a foundation for clinical assessment and an empirical basis for risk assessment instrument norms, which inform expected recidivism rates. The present study explored the extent to which base rates influence the validity of risk assessment instruments.
METHODS: We systematically reviewed the available evidence on the discrimination ability of four well-established risk assessment instruments used to estimate the probability of recidivism for general (Level of Service Inventory-Revised [LSI-R]), violent (Violence Risk Appraisal Guide [VRAG]), sexual (Static-99R), and intimate partner violent offences (Ontario Domestic Assault Risk Assessment [ODARA]). We conducted a bivariate logit-normal random effects meta-analysis of sensitivity and false positive rates and modelled the positive and negative predictive values. We used base rates as reported in (a) the construction samples of each risk assessment instrument and (b) recent official statistics and peer-reviewed articles for different offence categories and countries. To assess the risk of bias, we used the Joanna Briggs Institute Critical Appraisal Checklist for Diagnostic Test Accuracy Studies.
RESULTS: We screened 644 studies and subsequently analysed 102, of which 96 were included in the systematic review and 24 in the meta-analyses. Discrimination was comparable for all four instruments (median area under the curve = 0.68–0.71). The information needed to calculate summary statistics of sensitivity and false positive rate was often not reported, and a risk of bias may be present in up to half of the studies. The largest summary sensitivity and false positive rate were estimated for the ODARA, followed by the LSI-R, the VRAG, and the Static-99R. If base rates are low, positive predictive values tend to be relatively low, while negative predictive values are higher: positive predictive value = 0.032–0.133 and negative predictive value = 0.985–0.989 for sexual offences; positive predictive value = 188–0.281 and negative predictive value = 0.884–0.964 for intimate partner violence; positive predictive value = 0.218–0.241 and negative predictive value = 0.907–0.942 for violent offences; positive predictive value = 0.335–0.377 and negative predictive value = 0.809–0.810 for general offences.
CONCLUSIONS: When interpreting the results of individual risk assessments, it is not sufficient to provide the discrimination of the instrument; the risk statement must also address the positive predictive value and discuss its implications for the specific case. As recidivism rates are neither stable over time nor uniform across countries or samples, the primary interpretation of risk assessment instruments should rely on the percentile rank. Expected recidivism rates should be interpreted with caution. However, our results are drawn from a limited database, as studies not reporting sufficient information were excluded from analyses and it was only possible to identify current base rates for modelling positive and negative predictive values for certain countries. International standards for consistently collecting and reporting base rates are important to better identify crime trends. Future research on the validity of risk assessment instruments should follow rigorous reporting standards.publishe
Olfactory Receptor Responses to Pure Odorants in Drosophila melanogaster
No full textOlfactory coding relies on primary information from olfactory receptor cells that respond to volatile airborne substances. Despite extensive efforts, our understanding of odor-response profiles across receptors is still poor, because of the vast number of possible ligands (odorants), the high sensitivity even to trace compounds (creating false positive responses), and the diversity of olfactory receptors. Here, we linked chemical purification with a gas chromatograph to single-receptor type recording with transgenic flies using calcium imaging to record olfactory responses to a large panel of chemicals in seven Drosophila ORs: Or10a, Or13a, Or22a, Or42b, Or47a, Or56a, and Or92a. We analyze the data using linear–nonlinear modeling and reveal that most receptors have “simple” response types (mostly positive: Or10a, Or13a, Or22a, Or47a, and Or56a). However, two receptors (Or42b and Or92a) have, in addition to “simple” responses, “complex” response types to some ligands, either positive with a negative second phase or negative with a positive second phase, suggesting the presence of multiple binding sites and/or transduction cascades. We show that some ligands reported in the literature are false positives, because of contaminations in the stimulus. We recorded all stimuli across concentrations, showing that at different concentrations, different substances appear as best ligands. Our data show that studying combinatorial olfactory coding must consider temporal response properties and odorant concentration and, in addition, is strongly influenced by the presence of trace amounts of ligands (contaminations) in the samples. These observations have important repercussions for our thinking about how animals navigate their olfactory environment.publishe
A toolbox for calculating quantitative image properties in aesthetics research
No full textOver the past two decades, researchers in the field of visual aesthetics have studied numerous quantitative (objective) image properties and how they relate to visual aesthetic appreciation. However, results are difficult to compare between research groups. One reason is that researchers use different sets of image properties in their studies. However, even if the same properties are used, the image pre-processing techniques may differ, and researchers often use their own customized scripts to calculate the image properties. To provide better accessibility and comparability of research results in visual experimental aesthetics, we developed an open-access and easy-to-use toolbox called Aesthetics Toolbox. The Toolbox allows users to calculate a well-defined set of quantitative image properties popular in contemporary research. The properties include image dimensions, lightness and color statistics, complexity, symmetry, balance, Fourier spectrum properties, fractal dimension, self-similarity, as well as entropy measures and CNN-based variances. Compatible with most devices, the Toolbox provides an intuitive click-and-drop web interface. In the Toolbox, we integrated the original scripts of four different research groups and translated them into Python 3. To ensure that results were consistent across analyses, we took care that results from the Python versions of the scripts were the same as those from the original scripts. The toolbox, detailed documentation, and a link to the cloud version are available via GitHub: https://github.com/RBartho/Aesthetics-Toolbox. In summary, we developed a toolbox that helps to standardize and simplify the calculation of quantitative image properties for visual aesthetics research.publishe
Multiple Vulnerabilities : Knowledge Politics of School Closures During the COVID-19 Pandemic
No full textDer Beitrag beleuchtet die Debatte um die Schulschließungen während der COVID-19-Pandemie im Horizont einer Theorie multipler Vulnerabilitäten. Untersucht werden Zusammenhänge zwischen epistemisch-normativen Positionierungen und Vulnerabilitätsvorstellungen in einem Sample von 43 qualitativen Interviews mit engagierten Laien, die die Problematik der Schulschließungen auf Twitter diskutiert haben. Es kann gezeigt werden, dass Kinder aus Sicht der Kritiker*innen der Schulschließungen vor allem durch die psychischen und sozialen Folgen gefährdet sind, kaum aber durch die Krankheit selbst. Wer umgekehrt für Schulschließungen, Distanzunterricht oder Infektionsschutzmaßnahmen eintritt, sieht Kinder in erster Linie durch mögliche Infektionen bedroht und schätzt die psychischen und sozialen Folgen weniger problematisch ein. Trotz dieser als Polarisierung lesbaren Differenzen ist allen Interviewten eine Orientierung sowohl am Kindeswohl als auch am wissenschaftlichen Diskurs gemeinsam. Wir interpretieren die Ergebnisse wissens- und wissenschaftssoziologisch und verbinden die Theorie multipler Vulnerabilitäten mit einer Theorie multipler Fakten.publishe
Wintering, rather than breeding, oceanic conditions may modulate declining survival in a long-distance migratory seabird
No full textSteep declines in Arctic skua populations in the southern extent of their breeding range have been reported during the last half of the 20th century. We used 24 yr of ringing and re-encounter data from the Faroe Islands, North Atlantic, to investigate if patterns in survival probabilities can be explained by large-scale climatic events. Having first determined the migratory phenology and wintering regions, we estimated the effects of the North Atlantic Oscillation (NAO) index on survival during breeding and the Oceanic Niño index (ONI) during the non-breeding period within a capture-mark-recapture framework. Temporal trends along with direct and time-lagged effects of the environment on annual survival were modelled. We found support for a substantial decrease in adult annual survival, from ca. 0.93 in 1985 to ca. 0.77 in 2008, and weak support for a decrease in young (first year) survival over the duration of the study period. Furthermore, models indicated increased young survival following an El Niño winter. We suggest this time-lagged effect reflects downstream propagation of environmental conditions, particularly food availability, or a potential carry-over effect of El Niño conditions positively impacting the performance of the parents in the subsequent breeding season, leading to improved young survival prospects. While adult mortality cannot be attributed to the oceanic climate oscillations tested here, the negative trend in survival may account for the substantial population declines observed over the last decades.publishe
JUNB O-GlcNAcylation-Mediated Promoter Accessibility of Metabolic Genes Modulates Distinct Epithelial Lineage in Pulmonary Fibrosis
No full textIdiopathic pulmonary fibrosis (IPF) is a lethal disease with substantial unmet medical needs. While aberrant epithelial remodeling is a key factor in IPF progression, the molecular mechanisms behind this process remain elusive. Harnessing a 3D patient-derived organoid model and multi-omics approach, the first inventory of the connection between metabolic alteration, chromatin accessibility, and transcriptional regulation in IPF aberrant epithelial remodeling is provided. This remodeling is characterized by an increase in chromatin accessibility, particularly at JUNB motif-enriched promoter regions proximal to transcription start sites of metabolic and pro-fibrotic genes. Mechanistically, JUNB undergoes O-linked β-N-acetylglucosamine modification (O-GlcNAcylation), a critical step in modulating pro-fibrotic responses to chronic injury. This modification is pivotal in fostering the emergence of aberrant epithelial basal cells in the alveolar niche, a proposed driver of IPF pathology. Specific deletion of O-GlcNAcylation sites on JUNB attenuates the metaplastic differentiation of basal cells, thereby aiding in the restoration of the alveolar lineage. Together, the findings reveal a novel link between metabolic dysregulation and cell fate regulation at the chromatin level in fibrosis, mediated by the O-GlcNAc-JUNB axis, suggesting avenues for the development of new therapeutic strategies in IPF.publishe
Superfluidity and sound propagation in disordered Bose gases
No full textSuperfluidity describes the ability of quantum matter to flow without friction. Due to its fundamental role in many transport phenomena, it is crucial to understand the robustness of superfluid properties to external perturbations. Here, we theoretically study the effects of speckle disorder on the propagation of sound waves in a two-dimensional Bose-Einstein condensate at zero temperature. We numerically solve the Gross-Pitaevskii equation in the presence of disorder and employ a superfluid hydrodynamic approach to elucidate the role of the compressibility and superfluid fraction in the propagation of sound. A key result is that disorder reduces the superfluid fraction and hence the speed of sound; it also introduces damping and mode coupling. In the limit of weak disorder, the predictions for the speed of sound and its damping rate are well reproduced by a quadratic perturbation theory. The hydrodynamic description is valid over a wide range of parameters, while discrepancies become evident if the disorder becomes too strong, the effect being more significant for disorder applied in only one spatial direction. Our predictions are well within the reach of state-of-the-art cold-atom experiments and carry over to more general disorder potentials.publishe
Challenges and opportunities for validation of AI-based new approach methods
No full textThe integration of artificial intelligence (AI) into new approach methods (NAMs) for toxicology represents a paradigm shift in chemical safety assessment. Harnessing AI appropriately has enormous potential to streamline validation efforts. This review explores the challenges, opportunities, and future directions for validating AI-based NAMs, highlighting their transformative potential while acknowledging the complexities involved in their implementation and acceptance. We discuss key hurdles such as data quality, model interpretability, and regulatory acceptance, alongside opportunities including enhanced predictive power and efficient data integration. The concept of e-validation, an AI-powered framework for streamlining NAM validation, is presented as a comprehensive strategy to overcome limitations of traditional validation approaches, leveraging AI-powered modules for reference chemical selection, study simulation, mechanistic validation, and model training and evaluation. We propose robust validation strategies, including tiered approaches, performance benchmarking, uncertainty quantification, and cross-validation across diverse datasets. The importance of ongoing monitoring and refinement post-implementation is emphasized, addressing the dynamic nature of AI models. We consider ethical implications and the need for human oversight in AI-driven toxicology and outline the impact of trends in AI development, research priorities, and a vision for the integration of AI-based NAMs in toxicological practice, calling for collaboration among researchers, regulators, and industry stakeholders. We describe the vision of companion AI post-validation agents to keep methods and their validity status current. By addressing these challenges and opportunities, the scientific community can harness the potential of AI to enhance predictive toxicology while reducing reliance on traditional animal testing and increasing human relevance and translational capabilities.publishe