GENDER & CSCL EXPLORING THE RELATION OF COMPUTER-SUPPORTED COLLABORATIVE LEARNING (CSCL) AND GENDER BIAS IN RESEARCH AND PRACTICE

Achieving gender equity in education is an essential UN sustainable development goal. However, it is unclear which aspects of gender are important to consider in research findings and how to interpret findings in the context of gender stereotypes and biases. This lack of clarity is particularly salient in the STEM field. Computer-supported collaborative learning (CSCL) is a group learning method where learners work together on group tasks that aim to share and co-construct knowledge (Stahl, 2006). In addition to cognitive learning gains, the literature reports that CSCL can have social and psychological benefits, such as fostering positive interpersonal relationships and increased understanding of equity and diversity (Dillenbourg, 1999; Cress et al., 2021). In order to elaborate on the assumed potential of CSCL to support equity and diversity goals in education, this thesis focuses on the role of gender in CSCL research and practice. While previous studies have investigated gender differences in computer-supported collaborative learning (CSCL), there exists a dearth of research specifically addressing what role gender actually plays for learning in CSCL. Also, potential gender biases in CSCL research methodologies and their implications for CSCL practice have not been explored.The main goals of thesis are to inform educational practice in CSCL with recommendations for pedagogical and technical measures to create a more gender equity and inclusive education. Additionally, we aim to contribute empirically to the theoretical discussion on gender conceptualisations in research by applying socio-constructivist methodologies to understand the role of gender and gender diversity in CSCL. We also present alternative methods for assessing gender, gender diversity, and gender bias in CSCL research

Comparison between mirror Langmuir probe and gas puff imaging measurements of intermittent fluctuations in the Alcator C-Mod scrape-off layer

Statistical properties of the scrape-off layer (SOL) plasma fluctuations are studied in ohmically heated plasmas in the Alcator C-Mod tokamak. For the first time, plasma fluctuations as well as parameters that describe the fluctuations are compared across measurements from a mirror Langmuir probe (MLP) and from gas-puff imaging (GPI) that sample the same plasma discharge. This comparison is complemented by an analysis of line emission time-series data, synthesized from the MLP electron density and temperature measurements. The fluctuations observed by the MLP and GPI typically display relative fluctuation amplitudes of order unity together with positively skewed and flattened probability density functions. Such data time series are well described by an established stochastic framework which model the data as a superposition of uncorrelated, two-sided exponential pulses. The most important parameter of the process is the intermittency parameter, {\gamma} = {\tau}d / {\tau}w where {\tau}d denotes the duration time of a single pulse and {\tau}w gives the average waiting time between consecutive pulses. Here we show, using a new deconvolution method, that these parameters can be consistently estimated from different statistics of the data. We also show that the statistical properties of the data sampled by the MLP and GPI diagnostic are very similar. Finally, a comparison of the GPI signal to the synthetic line-emission time series suggests that the measured emission intensity can not be explained solely by a simplified model which neglects neutral particle dynamics

Outlier classification using Autoencoders: application for fluctuation driven flows in fusion plasmas

Understanding the statistics of fluctuation driven flows in the boundary layer of magnetically confined plasmas is desired to accurately model the lifetime of the vacuum vessel components. Mirror Langmuir probes (MLPs) are a novel diagnostic that uniquely allow to sample the plasma parameters on a time scale shorter than the characteristic time scale of their fluctuations. Sudden large-amplitude fluctuations in the plasma degrade the precision and accuracy of the plasma parameters reported by MLPs for cases in which the probe bias range is of insufficient amplitude. While some data samples can readily be classified as valid and invalid, we find that such a classification may be ambiguous for up to 40% of data sampled for the plasma parameters and bias voltages considered in this study. In this contribution we employ an autoencoder (AE) to learn a low-dimensional representation of valid data samples. By definition, the coordinates in this space are the features that mostly characterize valid data. Ambiguous data samples are classified in this space using standard classifiers for vectorial data. This way, we avoid to define complicate threshold rules to identify outliers, which requires strong assumptions and introduce biases in the analysis. Instead, these rules are learned from the data by statistical inference By removing the outliers that are identified in the latent low-dimensional space of the AE, we find that the average conductive and convective radial heat flux are between approximately 5 and 15% lower as when removing outliers identified by threshold values. For contributions to the radial heat flux due to triple correlations, the difference is up to 40%

Socio-cultural norms of body size in Westerners and Polynesians affect heart rate variability and emotion during social interactions

The perception of body size and thus weight-related stigmatization vary between cultures. Both are stronger in Western than in Polynesian societies. Negative emotional experiences alter one’s behavioral, psychological, and physiological reactions in social interactions. This study compared affective and autonomic nervous system responses to social interactions in Germany and American Samoa, two societies with different body-size related norms. German (n = 55) and Samoan (n = 56) volunteers with and without obesity participated in a virtual ball-tossing game that comprised episodes of social inclusion and social exclusion. During the experiment, heart rate was measured and parasympathetic activity (i.e., high-frequency heart rate variability) was analyzed. We found differences in both emotional experience and autonomic cardio-regulation between the two cultures: during social inclusion, Germans but not Samoans showed increased parasympathetic activity. In Germans with obesity, this increase was related to a more negative body image (comprising high rates of weight-related teasing). During social exclusion, Samoans showed parasympathetic withdrawal regardless of obesity status, while Germans with obesity showed a stronger increase in parasympathetic activity than lean Germans. Furthermore, we found fewer obesity-related differences in emotional arousal after social exclusion in Samoans as compared to Germans. Investigating the interplay of socio-cultural, psychological, and biological aspects, our results suggest influences of body size-related socio-cultural norms on parasympathetic cardio-regulation and negative emotions during social interactions

Complete Genome of “Candidatus Phytoplasma rubi” RS, a Phytopathogenic Bacterium Associated with Rubus Stunt Disease

The phytoplasma “Candidatus Phytoplasma rubi” is associated with Rubus stunt disease. The complete genome was determined by assembling Oxford Nanopore Technologies system-derived long reads, with short-read polishing with Illumina reads. The genome of strain RS, from Germany, is organized in one circular chromosome with a length of 762 kb

The sonographic digital portfolio: a longitudinal ultrasound image tracking program

BACKGROUND: Ultrasonography (US) at the medical student level is developing. As clinical skills and simulation centers expand, US equipment miniaturizes, and more students are exposed to ultrasound; a digital portfolio comprised of US images and videos may be useful in demonstrating experience and possibly competency. METHODS: Medical students participated in US curricula consisting of didactics and hands-on training. From 1 July 2006 to 30 June 2008, student images and videos were saved. Total images and videos were evaluated and catalogued. RESULTS: A total of 10,074 images and 1,227 videos were saved during the 2-year period. For the academic year 2006 to 2007, 159 medical students obtained 3,641 of the images (84.9%) and 270 of the videos (86.0%). First year students obtained 778 images and 20 videos; second year students, 1,174 images and 64 videos; third year students, 211 images and 20 videos; and fourth year students, 1,478 images and 166 videos. For the academic year 2007 to 2008, 222 medical students obtained 4,340 images (75%) and 619 videos (67.8%). First year students obtained 624 images and 109 videos; second year students, 555 images and 81 videos; third year students, 132 images and 14 videos; and fourth year students, 3,029 images and 415 videos. CONCLUSIONS: The ultrasound digital portfolio allows medical students to collate and document their ultrasound experience. Currently, there is no requirement for ultrasound training, documentation of competency, or minimum numbers of US exams for medical education. The ultrasound digital portfolio may be a useful tool in documenting ultrasound proficiency

A genome-wide association study on hematopoietic stem cell transplantation reveals novel genomic loci associated with transplant outcomes

Copyright \ua9 2024 Rosenberger, Crossland, Dressel, Kube, Wolff, Wulf, Bickeb\uf6ller, Dickinson and Holler.Introduction: Data on genomic susceptibility for adverse outcomes after hematopoietic stem cell transplantation (HSCT) for recipients are scarce. Methods: We performed a genome wide association study (GWAS) to identify genes associated with survival/mortality, relapse, and severe graft-versus-host disease (sGvHD), fitting proportional hazard and subdistributional models to data of n=1,392 recipients of European ancestry from three centres. Results: The single nucleotide polymorphism (SNP) rs17154454, intronic to the neuronal growth guidant semaphorin 3C gene (SEMA3C), was genome-wide significantly associated with event-free survival (p=7.0x10-8) and sGvHD (p=7.5x10-8). Further associations were detected for SNPs in the Paxillin gene (PXN) with death without prior relapse or sGvHD, as well as for SNPs of the Plasmacytoma Variant Translocation 1 gene (PVT1, a long non-coding RNA gene), the Melanocortin 5 Receptor (MC5R) gene and the WW Domain Containing Oxidoreductase gene (WWOX), all associated with the occurrence of sGvHD. Functional considerations support the observed associations. Discussion: Thus, new genes were identified, potentially influencing the outcome of HSCT

Diagnostic value of diffusion-weighted STEAM-MRI in ischemic stroke

Introduction: Diffusion-weighted imaging in stimulated echo acquisition mode (STEAM-DWI) is an interesting alternative with less susceptibility artifacts compared to the most commonly used diffusion-weighted echo-planar imaging (EPI-DWI). Sensitivity and specificity of a novel STEAM-DWI, described by Merrem et al. 2017 [1], were assessed in patients with ischemic stroke. Methods: EPI- and STEAM-DWIs were performed in patients with suspected subacute stroke between 01 July 2019 and 30 June 2020 using 3-T MRI. Three neuroradiologists independently and separately rated STEAM-DWI images with respect to (i) signs of an acute/subacute stroke, (ii) the number, size and localization of infarctions and, (iii) the presence of artifacts. Results: In 55 (23 right, 23 left, 9 both hemispheres) of 85 patients a subacute stroke was confirmed using EPI- DWI. The cerebral vascular territories were affected as follows: anterior cerebral artery 8 %, middle cerebral artery 48 %, posterior cerebral artery 27 %, brainstem 7 %, cerebellum 10 %. In 53 of 55 (96 %) cases the stroke was detected by usage of STEAM-DWI, in 35 of 37 patients microembolic events were noticed (95 %). Results showed a sensitivity and specificity of 100 % (70/70) for major infarcts (>9 mm2 in-plane) and a sensitivity of up to 94 % (121/129) for detecting subacute microembolic lesions. No susceptibility artifacts were noticed in STEAM-DWI. Conclusion: Compared to standard EPI-DWI, STEAM-DWI offers a more robust alternative for diagnosing subacute strokes in areas affected by susceptibility artifacts