Instructional support for learning with computer simulations

Computersimulationen ermöglichen Lernenden Vorteile im Zugang zu Experimenten, die im Biologieunterricht anderweitig oft schwer durchführbar sind. Für einen erfolgreichen Wissenserwerb mit Computersimulationen benötigen Lernende jedoch instruktionale Unterstützung, da entdeckendes, selbstständiges Erarbeiten von biologischen Prinzipien und Konzepten mit Computersimulationen allein meist nicht zu gewünschten Lernerfolgen führt. Die Dateninterpretation und die Selbstregulation des Lernprozesses gelten als zwei identifizierte Problembereiche naturwissenschaftlichen Lernens mit Computersimulationen. Ziel dieser Forschungsarbeit ist ein Beitrag zur Klärung der Frage, mit welchen ausgewählten instruktionalen Maßnahmen zur Dateninterpretation und zur Selbstregulation sich der Wissenserwerb beim Lernen mit Computersimulationen im Fach Biologie verbessern lässt. Es wurde empirisch untersucht, welche Effekte diese instruktionalen Maßnahmen auf den Erwerb von Wissen in den verschiedenen Kategorien Faktenwissen, konzeptuelles Wissen, prozedurales Wissen und intuitives Wissen zeigen. Es wurden ein Computerprogramm zum Thema „Gewässerökologie“ mit einer Computersimulation zur Räuber-Beute-Beziehung sowie ausgewählte, konkrete instruktionale Maßnahmen zur Dateninterpretation und zur Selbstregulation beim Lernen mit Computersimulationen entwickelt und in einer Studie im Biologieunterricht achter Realschulklassen getestet. Die Ergebnisse zeigen, dass sich die instruktionalen Maßnahmen zur Dateninterpretation und zur Selbstregulation unterschiedlich effektiv auf die Aneignung themenspezifischen Wissens in den verschiedenen Kategorien auswirken. Als vergleichsweise effektive Unterstützung für einen Lernerfolg zeigt sich die instruktionale Maßnahme zur Dateninterpretation, das eigene Simulationsergebnis zu beschreiben und biologisch zu interpretieren. Des Weiteren zeigt eine bestimmte Kombination aus einer instruktionalen Maßnahme zur Dateninterpretation und zur Selbstregulation geringe Effekte auf einen Lernerfolg. In diesem Zusammenhang erscheint die Beschreibung und Interpretation des eigenen Simulationsergebnisses als instruktionale Maßnahme zur Dateninterpretation sowie eine zusätzliche Reflexion über diese Ergebnisse als instruktionale Maßnahme zur Selbstregulation für die erfolgreiche Aneignung von Wissen in den genannten Wissenskategorien beim Lernen mit Computersimulationen als hinderlich. Lernende, die diese instruktionale Maßnahmenkombination erhielten, zeigen zudem eine vergleichsweise hohe, subjektiv wahrgenommene kognitive Belastung während der Arbeit mit der Computersimulation, die nach jeder Intervention von den Lernenden selbst eingeschätzt wurde. Die kognitive Belastung könnte einen kausalen Zusammenhang darstellen, warum sich diese bestimmte Kombination aus zwei verschiedenen instruktionalen Maßnahmen hinsichtlich der themenspezifischen Wissensaneignung in den unterschiedlichen Wissenskategorien beim Lernen mit Computersimulationen als vergleichsweise wenig effektiv erweist.Computer simulations provide learners with the opportunity to carry out experiments that are otherwise often difficult to conduct in school. For successful knowledge acquisition when learning with computer simulations instructional support is needed, as pure discovery learning with computer simulations does not typically result in desirable learning outcomes. Data interpretation and self-regulation of the learning process are identified as two problem areas of scientific learning with computer simulations. Goal of this research project is a contribution to clarify the question, what kind of instructional measures for data interpretation and for self-regulation when learning with computer simulations is crucial to increase students’ biological knowledge. In an empirical study, effects of these instructional measures on the different knowledge types- factual, conceptual, procedural and intuitive knowledge- were testet. For this reason, a water ecological computer program containing a computer simulation about a predator-prey-relationship as well as particular instructional measures for data interpretation and for self-regulation when learning with computer simulations are developed and testet with eight grade secondary school students in biology lessons. Results show different effects of the instructional measures for data interpretation and for self-regulation on domain specific knowledge acquisition concerning the different knowledge types. A comparatively especial effective learning support appears the instructional measure for data interpretation, to describe and to interpret biological the own simulation outcome. Furthermore, a certain combination of an instructional measure for data interpretation and an instructional measure for self-regulation shows little effects for learning outcomes. In this regard, describing and interpreting the own simulation outcome as instructional measure for data interpretation as well as additionally reflection about these results as instructional measure for self-regulation seem to be detrimental for successful knowledge acquisition. Students who received these both types of instructional support also showed the highest values of cognitive load, which was self-assessed by the students after every session. Cognitive load could be a reason why a certain combination of instructional measures lead to contrary effects for students’ knowledge acquisition when learning with computer simulations

Reimbursement Status and Recommendations Related to Orphan Drugs in European Countries

Objective: To review the reimbursement recommendations issued by selected European health technology assessment agencies for orphan drugs and the reimbursement status of these drugs; to assess the relationship between the type of recommendation and reimbursement status. Methods: The list of orphan drugs to be included in the analysis was obtained from the European Medicines Agency and Orphanet. Seven European states were included in the analysis: Belgium, England, France, Germany, Poland, Scotland, and Spain. For all identified orphan drugs, relevant data on the reimbursement status and type of recommendation were collected for each country. The relationship between the type of recommendation and reimbursement status was evaluated separately for each considered country, using Cohen’s kappa coefficient for the measurement of agreement; sub-analyses for oncology and metabolic drugs were performed. Results: Most reimbursement recommendations for orphan drugs were positive (71%), while approximately 17% were negative and almost 13% were conditional. The highest percentage of positive reimbursement recommendations was observed in Spain (97%) and France (95%) and the highest percentage of negative reimbursement recommendations was revealed for Poland (49%). On average, 65% of the 163 analyzed orphan drugs were reimbursed from public funds. The highest number of reimbursed orphan drugs was observed in Germany (n = 148), while the lowest, in Poland (n = 41). Considering all analyzed drugs, the highest agreement between recommendations and reimbursement status was observed for Spain (value of 1), and the lowest, for Germany (κ = -0.03). Conclusions: On average, more than 60% of identified orphan drugs were reimbursed from public funds in the included countries, and the majority of reimbursement recommendations were found to be positive. The agreement between reimbursement recommendations and reimbursement status differed between the countries, but overall, it did not show any patterns, as it ranged from -0.03 to 1 (κ coefficient)

The rise of fully turbulent flow

Over a century of research into the origin of turbulence in wallbounded shear flows has resulted in a puzzling picture in which turbulence appears in a variety of different states competing with laminar background flow. At slightly higher speeds the situation changes distinctly and the entire flow is turbulent. Neither the origin of the different states encountered during transition, nor their front dynamics, let alone the transformation to full turbulence could be explained to date. Combining experiments, theory and computer simulations here we uncover the bifurcation scenario organising the route to fully turbulent pipe flow and explain the front dynamics of the different states encountered in the process. Key to resolving this problem is the interpretation of the flow as a bistable system with nonlinear propagation (advection) of turbulent fronts. These findings bridge the gap between our understanding of the onset of turbulence and fully turbulent flows.Comment: 31 pages, 9 figure

Effect of Bacillus subtilis Strains on Intestinal Barrier Function and Inflammatory Response

Strong tight junctions and curtailed inflammatory responses under stressful conditions are key for optimal digestive health. Bacillus-based probiotics are increasingly being used to maintain broilers' health, but their mode of action is often not well-defined. In the present study we used Caco-2 cells as a model for intestinal epithelia and assessed the effect of three Bacillus-based probiotics on intestinal barrier function and intestinal inflammation. Experimental results showed that one of the three tested strains, Bs 29784, significantly reinforced intestinal barrier integrity under basal conditions through an up-regulation of the expression of tight junction's proteins, whereas the others had no or detrimental effects. When Caco-2 cells were pre-treated with Bacillus subtilis strains, the subsequent IL-8 release to various pro-inflammatory signals (IL-1β, deoxynivalenol, or flagellin) was blunted compared to cells that had not been pretreated, but to a different extent depending on the strain of Bacillus used. Bs 29784, was able to significantly decrease IL-8 production in all stressed conditions tested. Mechanistically, Bs 29784 appeared to limit nuclear translocation of NF-κB during IL-1β exposure by preventing IκB degradation. The effects of Bs 29784 were observed independently with supernatant and cells but in a lesser extent than with the combination, indicating that they can thus likely be attributed to both secreted metabolites and cell-associated compounds. Moreover, under inflammatory conditions, Bs 29784 significantly reduced the upregulation of iNOS protein levels further underlining its intestinal anti-inflammatory potential. Our data show that Bacillus-based probiotics may indeed improve digestive health by strengthening intestinal barrier and limiting inflammatory responses and that these properties are strain-dependent

Analysis of Clonal Type-Specific Antibody Reactions in Toxoplasma gondii Seropositive Humans from Germany by Peptide-Microarray

BACKGROUND: Different clonal types of Toxoplasma gondii are thought to be associated with distinct clinical manifestations of infections. Serotyping is a novel technique which may allow to determine the clonal type of T. gondii humans are infected with and to extend typing studies to larger populations which include infected but non-diseased individuals. METHODOLOGY: A peptide-microarray test for T. gondii serotyping was established with 54 previously published synthetic peptides, which mimic clonal type-specific epitopes. The test was applied to human sera (n = 174) collected from individuals with an acute T. gondii infection (n = 21), a latent T. gondii infection (n = 53) and from T. gondii-seropositive forest workers (n = 100). FINDINGS: The majority (n = 124; 71%) of all T. gondii seropositive human sera showed reactions against synthetic peptides with sequences specific for clonal type II (type II peptides). Type I and type III peptides were recognized by 42% (n = 73) or 16% (n = 28) of the human sera, respectively, while type II-III, type I-III or type I-II peptides were recognized by 49% (n = 85), 36% (n = 62) or 14% (n = 25) of the sera, respectively. Highest reaction intensities were observed with synthetic peptides mimicking type II-specific epitopes. A proportion of the sera (n = 22; 13%) showed no reaction with type-specific peptides. Individuals with acute toxoplasmosis reacted with a statistically significantly higher number of peptides as compared to individuals with latent T. gondii infection or seropositive forest workers. CONCLUSIONS: Type II-specific reactions were overrepresented and higher in intensity in the study population, which was in accord with genotyping studies on T. gondii oocysts previously conducted in the same area. There were also individuals with type I- or type III-specific reactions. Well-characterized reference sera and further specific peptide markers are needed to establish and to perform future serotyping approaches with higher resolution

Maternal Genome-Wide DNA Methylation Patterns and Congenital Heart Defects

The majority of congenital heart defects (CHDs) are thought to result from the interaction between multiple genetic, epigenetic, environmental, and lifestyle factors. Epigenetic mechanisms are attractive targets in the study of complex diseases because they may be altered by environmental factors and dietary interventions. We conducted a population based, case-control study of genome-wide maternal DNA methylation to determine if alterations in gene-specific methylation were associated with CHDs. Using the Illumina Infinium Human Methylation27 BeadChip, we assessed maternal gene-specific methylation in over 27,000 CpG sites from DNA isolated from peripheral blood lymphocytes. Our study sample included 180 mothers with non-syndromic CHD-affected pregnancies (cases) and 187 mothers with unaffected pregnancies (controls). Using a multi-factorial statistical model, we observed differential methylation between cases and controls at multiple CpG sites, although no CpG site reached the most stringent level of genome-wide statistical significance. The majority of differentially methylated CpG sites were hypermethylated in cases and located within CpG islands. Gene Set Enrichment Analysis (GSEA) revealed that the genes of interest were enriched in multiple biological processes involved in fetal development. Associations with canonical pathways previously shown to be involved in fetal organogenesis were also observed. We present preliminary evidence that alterations in maternal DNA methylation may be associated with CHDs. Our results suggest that further studies involving maternal epigenetic patterns and CHDs are warranted. Multiple candidate processes and pathways for future study have been identified

Re-examining the Unified Theory of Acceptance and Use of Technology (UTAUT): Towards a Revised Theoretical Model

YesBased on a critical review of the Unified Theory of Acceptance and Use of Technology (UTAUT), this study first formalized an alternative theoretical model for explaining the acceptance and use of information system (IS) and information technology (IT) innovations. The revised theoretical model was then empirically examined using a combination of meta-analysis and structural equation modelling (MASEM) techniques. The meta-analysis was based on 1600 observations on 21 relationships coded from 162 prior studies on IS/IT acceptance and use. The SEM analysis showed that attitude: was central to behavioural intentions and usage behaviours, partially mediated the effects of exogenous constructs on behavioural intentions, and had a direct influence on usage behaviours. A number of implications for theory and practice are derived based on the findings

Documenting the Natural History of Patients With Resected Stage II Adenocarcinoma of the Colon After Random Assignment to Adjuvant Treatment With Edrecolomab or Observation: Results From CALGB 9581

We conducted a randomized trial comparing adjuvant treatment with edrecolomab versus observation in patients with resected, low-risk, stage II colon cancer. This study also prospectively studied patient- and tumor-specific markers of treatment outcome