Beyond p-values: Using Bayesian Data Analysis in Science Education Research

In light of the replication crisis in psychology, null-hypothesis significance testing (NHST) and p-values have been heavily criticized and various alternatives have been proposed, ranging from slight modifications of the current paradigm to banning p-values from journals. Since the physics education research community often relies on quantitative statistical approaches, the challenges the replication crisis poses to these approaches need to be considered. p-values suffer primarily from the fact that they carry little information by themselves and lend themselves to misinterpretations. As one alternative, Bayesian approaches have become increasingly popular as the posterior distributions they provide carry more relevant information than p-values. In this paper, we discuss practical issues related to p-values with respect to interpreting and communicating results and how these issues can be addressed using a Bayesian approach. Drawing on a science education data set, we demonstrate how Bayesian data analysis methods go beyond p-values and can help to make more valid conclusions and to communicate them more easily in a manner that lends itself to less misinterpretations

Determinants of Dropout From Correctional Offender Treatment

Research indicates that approximately one third of offenders admitted to social-therapeutic correctional facilities in Germany fail to complete treatment and that treatment dropout is linked to higher recidivism in both sexual and violent offenders. The purpose of this study was to examine determinants of treatment dropout in a social-therapeutic correctional facility in Germany. The sample consisted of 205 incarcerated adult male offenders (49.8% sexual, 38.1% non-sexual violent) admitted to correctional treatment. Completers and dropouts were compared on variables pertaining to demographics, offense type, substance abuse, psychopathy, risk, and protective factors. Univariate analyses showed that treatment dropouts demonstrated significantly higher scores on measures of risk and psychopathy and lower scores on protective factors. Logistic regression analyses identified unemployment, non-sexual violent index offense, higher risk scores (HCR-20), and Facet 1 (interpersonal deficits) of the Psychopathy Checklist-Revised (PCL-R) as significant predictors of treatment dropout. Surprisingly, substance abuse disorder was a negative predictor of dropout. With the exception of substance abuse, the results support the notion that treatment dropouts represent a group of high-risk offenders with particular treatment needs. Practical implications and suggestions for further research are discussed

Aufbau einer elektrisch angetriebenen Tragschrauberkonfiguration für den urbanen Luftverkehr

Im DLR Forschungsprojekt S²TOL (Silent Short Takeoff and Landing) wird an einem neuen Konzept für ein leises und kurzstartfähiges Luftfahrzeug für den urbanen Luftverkehr geforscht. Während weltweit verschie-dene Hersteller auf Konfigurationen mit schwenkbaren Triebwerken oder auf Multicopter setzen, dient hier ein Tragschrauber als Ausgangsplattform. Tragschrauber bieten neben einer hohen Wendigkeit und sehr guten Kurzstartfähigkeiten eine geringe Komplexität und niedrige Betriebskosten. Das Prinzip der Autorotation bietet zudem ein hohes Maß an Flugsicherheit bei einem Triebwerksausfall. Das Konzept sieht eine elektri-sche Auslegung des Tragschraubers mit zwei Elektromotoren für den Vortrieb und einem Elektromotor für die Vorrotation vor. Dabei wird besonderer Wert auf eine lärmoptimierte Umsetzung gelegt. Allein durch eine Neuauslegung und Anordnung von Propellern und Rotoren wird eine signifikante Reduktion der Lärmimmis-sion erwartet. In Kombination mit dem Elektromotor ist zudem emissionsfreies Fliegen möglich. Durch inno-vative Technologien wie eine Schubvektorsteuerung soll die Kurzstartfähigkeit weiter optimiert werden. Es werden zwei Antriebsvarianten betrachtet und hinsichtlich ihrer Flugleistungen und Lärmemission untersucht. Bei Variante 1 wird der Vortrieb durch zwei große Zugpropeller bereitgestellt, bei Variante 2 kommen Mantel-propeller zum Einsatz, die weiteres Potential zur Lärmreduktion bieten. Durch Prüfstandtests konnte bereits der Standschub für beide Varianten nachgewiesen werden. Zusätzliche analytische Betrachtungen geben zudem erste Aufschlüsse über das erwartete Verhalten im Flugversuch

Botulinum Toxin Therapy for Psychiatric Disorders in Clinical Practice: A Retrospective Case Study

Inhibiting the facial expression of negative emotions via botulinum toxin A (BTX) has been shown to mitigate symptoms of clinical depression in randomized controlled trials. This retrospective case study sought to reproduce the beneficial effects of BTX in a naturalistic setting for major depressive disorder and collect casuistic data on its effect on other mental disorders. Moreover, we describe symptom development across multiple treatment cycles with BTX, and assess the implementation of additional injection targets in the lower face region. Participants were N = 51 adult psychiatric outpatients mainly seeking treatment for depression. Over 50% suffered from comorbid psychiatric conditions, predominantly generalized anxiety disorder (GAD) or borderline personality disorder (BPD). A pre–post case series design was adapted. All participants received BTX-injections in the glabellar region on at least one occasion. Some received additional injections in the mouth region and over multiple treatment cycles. Treatment response was followed up by self-rated scales at varying time intervals post treatment. The results showed that BTX may yield favorable outcomes across multiple and comorbid mental disorders, especially, however, for patients suffering from depression. It potentially prevents the recurrence of clinical symptoms if applied regularly. Adding additional regions of the face does not seem to be superior over applying it to the glabellar region alone. The results add to the growing evidence that BTX therapy is effective in alleviating symptoms of depression. Positive effects can be sustained and reinstated, when applied over multiple treatment cycles. Observed symptom reduction in other psychiatric disorders was less pronounced. Further research is needed to understand the mechanisms by which BTX therapy reduces psychiatric symptoms

Nasal microbiota and symptom persistence in acute respiratory tract infections in infants

Acute respiratory tract infections (ARI) in infancy have been implicated in the development of chronic respiratory disease, but the complex interplay between viruses, bacteria and host is not completely understood. We aimed to prospectively determine whether nasal microbiota changes occur between the onset of the first symptomatic ARI in the first year of life and 3 weeks later, and to explore possible associations with the duration of respiratory symptoms, as well as with host, environmental and viral factors. Nasal microbiota of 167 infants were determined at both time-points by 16S ribosomal RNA-encoding gene PCR amplification and subsequent pyrosequencing. Infants were clustered based on their nasal microbiota using hierarchical clustering methods at both time-points. We identified five dominant infant clusters with distinct microbiota at the onset of ARI but only three clusters after 3 weeks. In these three clusters, symptom persistence was overrepresented in the Streptococcaceae-dominated cluster and underrepresented in the cluster dominated by “Others” (p<0.001). Duration of symptoms was not associated with the type of respiratory virus. Infants with prolonged respiratory symptoms after their first ARI tend to exhibit distinct microbial compositions, indicating close microbiota–host interactions that seem to be of importance for symptom persistence and recovery