Mediamusic (E-Journal)
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Hair cortisol-a stress marker in children and adolescents with chronic tic disorders?:A large European cross-sectional study
No full textBACKGROUND: There is clear evidence that tic disorders (TDs) are associated with psychosocial stress as well as emotional and behavioral problems. Studies have shown that individuals with TDs have higher acute physiological stress responses to external, single stressors (as reflected by saliva cortisol). The aim of the present study was to examine a physiological marker of longer-term stress (as reflected by hair cortisol concentration) in children and adolescents with TDs and unaffected siblings of individuals with TDs.METHODS: Two samples of a European cohort were included in this study. In the COURSE sample, 412 children and adolescents aged 3-16 years with a chronic TD including Tourette syndrome according to DSM IV-TR criteria were included. The ONSET sample included 131 3-10 years old siblings of individuals with TDs, who themselves had no tics. Differences in hair cortisol concentration (HCC) between the two samples were examined. Within the COURSE sample, relations of HCC with tic severity and perceived psychosocial stress as well as potential effects and interaction effects of comorbid emotional and behavioral problems and psychotropic medication on HCC were investigated.RESULTS: There were no differences in HCC between the two samples. In participants with TDs, there were no associations between HCC and tic severity or perceived psychosocial stress. No main effects of sex, psychotropic medication status and comorbid emotional and behavioral problems on HCC were found in participants with TDs.CONCLUSION: A link between HCC and TDs is not supported by the present results.</p
Rational points on del Pezzo surfaces of degree four
No full textWe study the distribution of the Brauer group and the frequency of the Brauer-Manin obstruction to the Hasse principle and weak approximation in a family of smooth del Pezzo surfaces of degree four over the rationals. We also study the geometry and arithmetic of a genus one fibration with two reducible fibres for which a Brauer element is vertical
The contemporary pulmonary artery catheter. Part 1:placement and waveform analysis
No full textNowadays, the classical pulmonary artery catheter (PAC) has an almost 50-year-old history of its clinical use for hemodynamic monitoring. In recent years, the PAC evolved from a device that enabled intermittent cardiac output measurements in combination with static pressures to a monitoring tool that provides continuous data on cardiac output, oxygen supply and-demand balance, as well as right ventricular (RV) performance. In this review, which consists of two parts, we will introduce the difference between intermittent pulmonary artery thermodilution using cold bolus injections, and the contemporary PAC enabling continuous measurements by using a thermal filament which at random heats up the blood. In this first part, the insertion techniques, interpretation of waveforms of the PAC, the interaction of waveforms with the respiratory cycle and airway pressure as well as pitfalls in waveform analysis are discussed. The second part will cover the measurements of the contemporary PAC including measurement of continuous cardiac output, RV ejection fraction, end-diastolic volume index, and mixed venous oxygen saturation. Limitations of all of these measurements will be highlighted there as well. We conclude that thorough understanding of measurements obtained from the PAC are the first step in successful application of the PAC in daily clinical practice.</p
The complex dynamics of adaptive teaching:Observing teacher-student interaction in the language classroom
No full textReal-time verbal interactions between foreign language teachers and their students are of vital importance for language development, but classroom interactions are also multi-faceted and complex. The way a teacher understands and responds to learner utterances can be a powerful pedagogical strategy to scaffold learner language development. In this paper we present the Questions and Answers in English Language Teaching coding scheme which can be used to observe and describe the dynamics of teacher questions and student responses in language classrooms. We piloted the instrument in English as a foreign language lessons of four experienced teachers teaching 16 lessons in total. State Space Grids were used to visualize classroom dynamics and quantify intra-individual variability of each lesson. The results show that interactions between teachers and students have the tendency to self-organize and stabilize in one specific area of the grid. Lessons taught by three of the teachers revealed a dominant pattern formed by closed questions and short student responses. One teacher taught lessons in which more complex question and answer sequences were prevalent. These patterns of variability and stability show that teacher-student interactions have the properties of a shallow attractor state. The analysis of moment-to-moment turns in classroom interaction indicate that students in this study generally adapt their response to the level of teacher questions, but that teachers do not seem to adapt their questions to the level of the previous student answer. This suggests that, even for experienced teachers, scaffolding and adaptive teaching might be easier said than done
Aggregate Energy Production in Wind Farms via Dynamic Robust Coalitional Games
No full textThis letter investigates the benefits of aggregating independent wind power producers. First, we quantify the expected joint profit in the case where such producers act as a single entity in a one-stage contract interval, and in a multi-stage contract interval with recourse. Second, we provide a constructive method to design stable allocation mechanisms in the case where the expected profit is changing with time. Third, we prove that the allocation policy stabilizes the coalition by correcting allocations in real-time in the case where the realized power output deviates from the contract size of the ahead market.</p
Individual risk calculator to predict lymph node metastases in patients with submucosal (T1b) esophageal adenocarcinoma:a multicenter cohort study
No full textBackground Lymph node metastasis (LNM) is possible after endoscopic resection of early esophageal adenocarcinoma (EAC). This study aimed to develop and internally validate a prediction model that estimates the individual risk of metastases in patients with pT1b EAC.Methods A nationwide, retrospective, multicenter cohort study was conducted in patients with pT1b EAC treated with endoscopic resection and/or surgery between 1989 and 2016. The primary end point was presence of LNM in surgical resection specimens or detection of metastases during follow-up.All resection specimens were histologically reassessed by specialist gastrointestinal pathologists. Subdistribution hazard regression analysis was used to develop the prediction model. The discriminative ability of this model was assessed using the c-statistic.Results 248 patients with pT1b EAC were included. Metastases were seen in 78 patients, and the 5-year cumulative incidence was 30.9% (95% confidence interval [CI] 25.1%-36.8%). The risk of metastases increased with submucosal invasion depth (subdistribution hazard ratio [SHR] 1.08, 95%CI 1.02-1.14, for every increase of 500 mu m), lymphovascular invasion (SHR 2.95, 95%CI 1.95-4.45), and for larger tumors (SHR 1.23, 95%CI 1.10-1.37, for every increase of 10mm). The model demonstrated good discriminative ability (c-statistic 0.81, 95%CI 0.75-0.86).Conclusions A third of patients with pT1b EAC experienced metastases within 5 years. The probability of developing post-resection metastases was estimated with a personalized predicted risk score incorporating tumor invasion depth, tumor size, and lymphovascular invasion. This model requires external validation before implementation into clinical practice.</p
Making the Grade:Do International Branch Campuses and Their Home Campuses Differ in International Student Satisfaction With the Academic Experience?
No full textThis study investigates differences in academic satisfaction among undergraduate international students studying at international branch campuses (IBCs) and their home campuses, considering student stage of study, gender, and institution. It draws on data from 2,145 undergraduate international students enrolled at four home campuses and their six affiliated IBCs that responded to the 2018 International Student Barometer (ISB). Results indicate that international students studying at IBCs were significantly less satisfied with their academic experience-including constructs of academic and teaching quality, academic environment, and academic engagement-than international students studying at the associated home campuses. Results have important implications for how institutions carry out internationalization amid uncertain times; in particular, ensuring that the unique experiences of students are understood and considered in the planning and provision of transnational education.</p
Managing boundaries in multiteam structures:From parochialism to integrated pluralism
No full textMultiteam structures are increasingly used to coordinate complex tasks between different groups. To realize this potential, however, the members of a multiteam structure must manage a complex set of boundary relations within, between, and beyond the various constituent teams—boundary relations that can be cooperative, competitive, or some combination of both at the same time. This multimethod study provides insight into how multiteam structures can meet this challenge. Specifically, we examined how the different organizations that utilize and support the Dutch railway system learned to manage boundaries as they transitioned from a centralized, arms-length structure to a colocated, multiteam structure for coordinating disruption responses (i.e., the Rail Operations Control Center (ROCC)). In part 1 of our study, qualitative analyses of interview, observational, and archival data suggested that learning to manage boundaries within the ROCC was not simple or linear but evolved through trial and error during various phases. Ultimately, the ROCC developed an approach we call “integrated pluralism,” establishing a dynamic balance that combines both collaborative and competitive approaches to boundary management. In this manner, the ROCC teams were able to attain integrated solutions and coordinated task accomplishment while simultaneously defending internal team operations and home organization interests. In part 2, we employed an interrupted time series analysis to demonstrate that the implementation of the ROCC resulted in significant performance improvements. Consistent with the results of part 1, we found that these improvements emerged gradually over time as teams learned to work out their boundary relations and transitioned to integrated pluralism. These findings provide new insights into how individuals and teams can work together to tackle the unique boundary management challenges presented by multiteam structures and illuminate the dynamic trial and error process by which component teams can learn to both cooperate and compete
Leader Network Centrality and Team Performance:Team Size as Moderator and Collaboration as Mediator
No full textThe social network perspective provides a valuable lens to understand the effectiveness of team leaders. In understanding leadership impact in team networks, an important question concerns the structural influence of leader centrality in advice-giving networks on team performance. Taking the inconsistent evidence for the positive relationship of network centrality and leadership effectiveness as a starting point, we suggest that the positive impact of leader centrality in advice-giving networks is contingent on team needs for leadership to meet communication and coordination challenges, which we argue are larger in larger teams. Developing our analysis, we examine the mediating role of member collaboration in the relationship of leader network centrality and team performance as moderated by team size. Based on a multi-source data set of 542 employees and 71 team leaders, we found that leader centrality in advice-giving networks related positively to team performance in larger teams but negatively in smaller teams. Results supported the mediated moderation model via member collaboration in smaller teams, but not in larger teams
The importance of satisfying children’s basic psychological needs in primary school physical education for PE-motivation, and its relations with fundamental motor and PE-related skills
No full textBackground: Motivation for physical education (PE) is considered an important factor for the development of children’s physical skills during PE. According to self-determination theory, satisfaction of the psychological needs of autonomy, relatedness, and competence is related to higher levels of autonomous motivation, and lower levels of controlled motivation. To get a better insight into these relations, the present study examines whether satisfaction of the psychological needs is predictive of fundamental motor skills (FMS) and PE-related skills, both directly, and indirectly (via motivation, i.e. ‘the motivational sequence’). As PE-related skills are more representative to the skills that are generally practiced during PE, the strongest relations are expected for these types of skills.Method: In this study, 2224 children (51.6% boys, mean age 11.8 ± 0.55) of 89 primary schools filled out questionnaires assessing the satisfaction of their basic psychological needs and their motivation for PE. Using a block design, FMS were assessed using standardized tests, and a diverse set of PE-related skills that are explicitly practiced during PE-lessons were tested using valid and reliable tests. Structural equation models were built in Mplus to examine the hypothesized relations.Results: Competence, peer-relatedness, and teacher-relatedness were predictive of autonomous motivation, whereas only peer-relatedness was predictive of controlled motivation. Different relations with psychological needs and motivation were found for FMS and PE-related skills. Autonomous and controlled motivation predicted PE-related skills, whereas only controlled motivation predicted FMS, in both cases via direct and indirect paths. In addition, direct relations were found between competence and both FMS and PE-related skills, and of peer-relatedness and teacher-relatedness with FMS specifically.Conclusions: Satisfaction of the psychological needs seems important for children’s PE-motivation and for their skill development, both directly and indirectly. These results underline the important role that PE-teachers play in constructing a need-satisfying environment. The motivational sequence seems to be more applicable to PE-related skills than to FMS, showing that is important to choose adequate outcome measures when examining PE-motivation