Revisiting effects of teacher characteristics on physiological and psychological stress: a virtual reality study.

Identifying personal characteristics associated with teachers' stress is a longstanding research goal with important implications for practice. The present work revisits the effects of individual characteristics in terms of neuroticism, classroom management self-efficacy, and cognitive (reasoning) abilities on stress using virtual reality (VR). Relying on a sample of 56 German pre-service teachers (Mage = 22.73, SDage = 4.93; 50.9% females), we capitalized on a VR classroom environment that allowed the integration of experimental control and authentic teaching situations, where pre-service teachers responded to the disruptive behaviors of the student avatars. We focused on stress responses in terms of psychological stress (self-reported stress) assessed after the VR session, and physiological stress (heart rate) assessed during the VR session. A total of 30 (26) participants was assigned to a condition with higher (lower) levels of disruptive student behavior, referred to as higher and lower complexity condition, respectively. Results from linear mixed-effects models revealed that neuroticism positively predicted psychological and physiological stress responses in pre-service teachers, whereas classroom management self-efficacy and cognitive (reasoning) abilities were not significantly related to stress responses. Level of complexity and the interaction between complexity and individual characteristics did not have an effect. This study underlines the value of VR as a tool for psychological research and contributes to existing knowledge on teacher characteristics and stress.

The impact of free-radical stabilization techniques on in vivo subsurface mechanical properties in highly cross-linked polyethylene acetabular liners.

Highly cross-linked polyethylene (HXLPE) for total hip arthroplasty was developed to improve wear resistance in vivo and associated complications in comparison to ultrahigh molecular weight polyethylene. This material typically goes through various free-radical stabilization techniques by remelting, single-annealing, or sequentially annealing the polyethylene to improve in vivo oxidation and wear properties. The purpose of this study is to determine if there is evidence of subsurface microhardness changes in retrieved HXLPE liner at the rim and articular subsurface after extended in vivo time that could be associated with oxidation and its effects on mechanical properties and implant integrity. Retrieved HXLPE liners were chosen based on peak subsurface Fourier transform infrared spectroscopy oxidation values. Each was mechanically tested for subsurface microhardness at both the rim and articular surface using a validated microindentation technique. Rim testing demonstrated a decrease in mechanical integrity that corresponded to higher subsurface oxidation values regardless of the free-radical stabilization technique. At the articular surface, a decrease in mechanical integrity was observed near the surface corresponding to peak oxidation and Vicker's hardness, which decreased with increasing depths. This was found in all groups, with the exception of the single-annealed liners, which demonstrated decreased mechanical integrity trends at greater depths between 1.0 and 2.0 mm. Our results suggest that subsurface mechanical properties do change in vivo for certain implants. Though it is likely that the mechanical failures are multifactorial, we have shown that mechanical property degradation of HXLPE liners does occur with long-term in vivo exposure and should be considered a possible risk factor.

Different Levels of Context-Specificity of Teacher Self-Efficacy and Their Relations With Teaching Quality.

On the basis of Bandura's social cognitive theory, researchers often assume that a teachers' self-efficacy (TSE) will have a positive effect on teaching quality. However, the available empirical evidence is mixed. Building on previous research into TSE, we examined whether assessing class-/task-specific TSE gives a more accurate indication of the associations between TSE assessments and student-rated teaching quality. The analyses were based on the English sample of the Teaching and Learning International Survey (TALIS) Video Study. Mathematics teachers (N = 86) rated their self-efficacy beliefs using generalized task-specific TSE items and class-/task-specific TSE items. Their students (N = 1,930) rated the quality of teaching in their math class. Multilevel regression analyses revealed stronger associations between student-rated teaching quality and class-/task-specific TSE than generalized task-specific TSE. We discuss possible reasons for these results and outline the potential benefits of using class-specific assessments for future TSE research.

From Sustainable Global Value Chains to Circular Economy-Different Silos, Different Perspectives, but Many Opportunities to Build Bridges.

A growing interest in the circular economy concept has pushed the discourse in various management-related disciplines beyond established boundaries, with calls to better address how such a model may be developed in a world of global value chains. Still, the conventional linear economy model continues to dominate business, society, and research. While the concept of better connecting physical output and input flows at multiple production or consumption levels is becoming more accepted, it remains unclear how to make this happen while ensuring that sustainability targets are met or exceeded. Multiple scientific communities contribute different perspectives to this discourse, with promising opportunities for research. Circular economy and sustainability from business and economics perspectives are multifaceted. The existing body of knowledge needs to be advanced to assist private individuals, business managers, investors, or policymakers in making informed decisions. In this article for the inaugural issue, we provide a snapshot of the discourses among those who have studied the circular economy and its related topics. We outline conceptual inroads and potential research questions to encourage further circular economy and sustainability research and discourse from business or economics perspectives as well as from the broader transdisciplinary angle. We propose three research pathways: (1) connecting output with input needs in a global circular economy; (2) beyond today's business logic for a global circular economy; and (3) inclusion of the Global South in North-dominated circular economies. For each, we propose concepts, theories, or methodological approaches and offer various perspectives from the micro, macro, and meso levels.

The Impact of Free Radical Stabilization Techniques on in vivo Mechanical Changes in Highly Cross-Linked Polyethylene Acetabular Liners.

INTRODUCTION: Numerous thermal free radical stabilization techniques are used in the production of highly cross-linked polyethylene (HXLPE) to improve oxidative stability. Little knowledge exists on the effects of in vivo time on the mechanical properties of HXLPE. The purpose of this study was to determine if free radical stabilization of HXLPE impacts mechanical properties as well as oxidative stability of acetabular liner rims after extended in vivo time. METHODS: Retrieved and control remelted, single annealed and sequentially annealed HXLPE liner rims were tested for mechanical properties. Oxidation was measured with FTIR spectroscopy and crystalline phase composition measured with Raman spectroscopy. RESULTS: No correlation was found between in vivo, ex vivo time and hardness for annealed groups. A statistically significant difference in hardness was identified between free radical stabilization groups. No correlation between maximum rim oxidation and in vivo time was found. Detectable levels of rim oxidation were present in 100% of single annealed, 75% of sequentially annealed, and 25% of remelted retrieved liners. Single and sequentially annealed liners demonstrated oxidation and increased crystallinity. Rim mechanical properties change in vivo for implant types. With in vivo time, retrieved remelted HXLPE demonstrated decreased mechanical properties, whereas retrieved single and sequentially annealed HXLPE properties remained stable. All liner cohorts demonstrated evidence of rim oxidation. Subsequent changes in crystallinity were only observed in oxidized annealed liners. CONCLUSION: HXLPE acetabular liner rims show evidence of in vivo mechanical property degradation, notably in remelted HXLPE, which may be a risk factor in rim fracture and catastrophic implant failure.

The selection gap in teacher education: Adverse effects of ethnicity, gender, and socio-economic status on situational judgement test performance.

BACKGROUND: Situational judgement tests (SJTs) measure non-cognitive attributes and have recently drawn attention as a selection method for initial teacher education programmes. To date, very little is known about adverse impact in teacher selection SJT performance. AIMS: This study aimed to shed light on adverse effects of gender, ethnicity, and socio-economic status (SES) on SJT scores, by exploring both main effects and interactions, and considering both overall SJT performance and separate SJT domain scores (mindset, emotion regulation, and conscientiousness). SAMPLE: A total of 2,808 prospective teachers from the United Kingdom completed the SJTs as part of the initial stage of selection into a teacher education programme. METHODS: In addition to SJT scores, the variables gender (female vs. male), ethnicity (majority group vs. minority group), and home SES background (higher SES status vs. lower SES status) were used in the analyses. Regression models and moderated regression models were employed. RESULTS AND CONCLUSIONS: Results from the regression models revealed that gender effects (females scoring higher than males) were restricted to emotion regulation, while ethnicity effects (ethnic majority group members scoring higher than ethnic minority group members) emerged for SJT overall scores and all three domains. Moderated regression modelling results furthermore showed significant interactions (gender and ethnicity) for SJT overall scores and two domains. Considering the importance of reducing subgroup differences in selection test scores to ensure equal access to teacher education, this study's findings are a critical contribution. The partially differentiated results for overall vs. domain-specific scores point towards the promise of applying a domain-level perspective in research on teacher selection SJTs.

On the Role of Hollow Aluminium Oxide Microballoons during Machining of AZ31 Magnesium Syntactic Foam.

The role played by hollow ceramic thin-walled aluminium oxide microballoons on the shear deformation characteristics of AZ31 Magnesium syntactic foam is studied through high-speed machining. The ceramic microballoons embedded in the AZ31 matrix provides the necessary stiffness for these novel foams. The effect of hollow ceramic microballoon properties, such as the volume fraction, thin wall thickness to diameter ratio, and microballoon diameter, profoundly affects the chip formation. A novel force model has been proposed to explain the causes of variation in cutting forces during chip formation. The results showed an increase in machining forces during cutting AZ31 foams dispersed with higher volume fraction and finer microballoons. At a lower (Davg/h) ratio, the mode of microballoon deformation was a combination of bubble burst and fracture through an effective load transfer mechanism with the plastic AZ31 Mg matrix. The developed force model explained the key role played by AZ31 matrix/alumina microballoon on tool surface friction and showed a better agreement with measured machining forces.

Values-in-action that support safe production.

INTRODUCTION: Safe production is a sustainable approach to managing an organization's operations that considers the interests of both management and workers as salient stakeholders in a productive and safe workplace. A supportive culture enacts values versus only espousing them. These values-in-action are beliefs shared by both management and workers that align what should happen in performing organizational routines to be safe and be productive with what actually is done. However, the operations and safety management literature provides little guidance on which values-in-action are most important to safe production and how they work together to create a supportive culture. METHOD: The researchers conducted exploratory case studies in 10 manufacturing plants of 9 firms. The researchers compared plant managers' top-down perspectives on safety in the performance of work and workers' bottom-up experiences of the safety climate and their rates of injury on the job. Each case study used data collected from interviewing multiple managers, the administration of a climate survey to workers and the examination of the plant's injury rates over time as reported to its third party health and safety insurer. RESULTS: The researchers found that plants with four values-in-action -a commitment to safety, discipline, prevention and participation-were capable of safe production, while plants without those values were neither safe nor productive. Where culture and climate aligned lower rates of injury were experienced. DISCUSSION AND CONCLUSION: The four value-in-actions must all be present and work together in a self-reinforcing manner to engage workers and managers in achieving safe production. Practical application: Managers of both operations and safety functions do impact safety outcomes such as reducing injuries by creating a participatory environment that encourage learning that improves both safety and production routines.

How Should Stressors Be Examined in Teachers? Answering Questions about Dimensionality, Generalizability and Predictive Effects Using the Multicontext Stressors Scale.

Using the Multicontext Stressors Scale (MSS), this study investigates which factorial structure should be used to measure teacher stressors, and the extent to which this factorial structure of MSS remains invariant across gender. Subsequently, grounded in self-determination theory, the present study also examines the extent to which stressors may differentially predict teachers' psychological functioning. Participants were 584 (Mage = 45.04; SD = 8.97) secondary school teachers. Goodness-of-fit indices and estimated parameters of the models, together with latent correlations between stressors, offered support for the six-factor structure, whereas the opposite was true for the one-factor structure of the MSS. Results also supported gender invariance of the MSS. Predictive findings showed that student misbehavior, lack of shared decision-making, and workload stressors are negatively related to basic psychological needs. Likewise, results noted the important role of basic psychological needs to reach optimal teachers' psychological functioning. The results are discussed, arguing the importance of assessing and analyzing teacher stressors using a multifactorial and invariant scale. From a more practical approach, it seems important for school leaders to be especially vigilant about all stressors. Nonetheless, if they desire to prevent detrimental psychological functioning in teachers, special attention should be placed on stressors related to student misbehavior, lack of shared decision-making, and workload.

A Meta-Analysis of the Effects of Teacher Personality on Teacher Effectiveness and Burnout.

The question of what makes a good teacher has been asked by practitioners, policymakers, and researchers for decades. However, there is no guiding framework about which qualities are important for teachers. Thus, it is necessary to examine these qualities using a recognized framework and to summarize the previous literature on this topic. We conducted a meta-analysis on the 25 studies (total N = 6294) reporting the relationships between teacher Big Five personality domains (openness, conscientiousness, extraversion, agreeableness, and emotional stability) and two teacher job-related outcomes (i.e., teacher effectiveness and burnout). Furthermore, the influence of three moderators was assessed, namely, the type of teacher effectiveness measure (i.e., evaluations of teaching, student performance self-efficacy, classroom observation, and academic achievement), source of personality report (i.e., self-report vs other-report), and the instructed educational level (i.e., elementary, secondary, and tertiary). Overall, teacher Big Five domains (except for agreeableness) were positively associated with teacher effectiveness, especially for evaluations of teaching. Furthermore, teacher emotional stability, extraversion, and conscientiousness were negatively associated with burnout. Other-reports of teacher personality were more strongly associated with outcomes than self-reports. There were no differences in the strength of the associations between the educational levels. The need for using common descriptors in teacher research as well as practical implications of the findings for teacher personality measurement is discussed.

Manufacturing, oxidation, mechanical properties and clinical performance of highly cross-linked polyethylene in total hip arthroplasty.

Ultra-high molecular weight polyethylene (UHMWPE) continues to be the gold standard bearing surface in total hip arthroplasty (THA) for nearly 5 decades. Highly cross-linked UHMWPE (HXLPE) was adapted for routine use in the early 2000s to reduce the revision rates related to wear, osteolysis, and aseptic loosening resulting from conventional UHMWPE wear. Since its inception, consistent evidence showing reduced wear rates and osteolysis supports the use of HXLPE in THA. High quality studies demonstrating the advantage in long term survivorship of HXLPE over conventional UHMWPE are emerging. Though retrieval studies have demonstrated evidence of in vivo oxidation and fatigue related damage at the rim of the first generation HXLPE liners, clinical significance of this remains to be seen. Second-generation sequentially annealed and vitamin E containing HXLPE liners demonstrate improved mechanical properties, resistance to oxidation, and equivalent wear rates in comparison to their first-generation counterparts, but long term success remains to be seen.

Self-efficacy beliefs of medical students: a critical review.

INTRODUCTION: Self-efficacy is a theoretically and empirically robust motivation belief that has been shown to play an important role in the learning and development of new skills and knowledge. In this article, we critically review research on the self-efficacy beliefs of medical students, with a goal to evaluate the existing research and to strengthen future work. In particular, we sought to describe the state of research on medical student self-efficacy and to critically examine the conceptualization and measurement of the construct. Finally, we aimed to provide directions for future self-efficacy research. METHODS: We critically reviewed 74 published articles that included measures of self-efficacy beliefs of medical students. RESULTS: Our review showed that (a) research on the self-efficacy beliefs of medical students is growing and is becoming increasingly international, and (b) that nearly half (46%) of self-efficacy measures showed conceptual and operational flaws. DISCUSSION: Our critical review of 74 research studies on self-efficacy of medical students found that although research in the field is increasing, nearly half of measures labelled as self-efficacy were incongruent with the conceptual guidelines set by self-efficacy experts. We provide five suggestions for future research on the self-efficacy of medical students.

Managing Safety and Operations: The Effect of Joint Management System Practices on Safety and Operational Outcomes.

OBJECTIVE: The aim of this study was to determine whether management system practices directed at both occupational health and safety (OHS) and operations (joint management system [JMS] practices) result in better outcomes in both areas than in alternative practices. METHODS: Separate regressions were estimated for OHS and operational outcomes using data from a survey along with administrative records on injuries and illnesses. RESULTS: Organizations with JMS practices had better operational and safety outcomes than organizations without these practices. They had similar OHS outcomes as those with operations-weak practices, and in some cases, better outcomes than organizations with safety-weak practices. They had similar operational outcomes as those with safety-weak practices, and better outcomes than those with operations-weak practices. CONCLUSIONS: Safety and operations appear complementary in organizations with JMS practices in that there is no penalty for either safety or operational outcomes.

Internalizing problems of adults with learning disabilities: a meta-analysis.

In this article the authors report a meta-analysis that examines the association between internalizing problems (anxiety and depressive symptoms) and learning disabilities (LD) in adults. Two hypotheses about the relationship between internalizing problems and LD in adults are posited and tested: the abeyance hypothesis (internalizing problems decline in adulthood) and the continuance hypothesis (internalizing problems continue in adulthood). From an initial pool of 171 relevant studies, 15 studies met the inclusion criteria, with eight published articles and seven dissertations yielding 48 effect sizes, N Total = 16,239). The overall effect size was significant and of medium magnitude (d = 0.51, p < .001). Results from the study suggest support for the continuance hypothesis, with rates of adult internalizing problems similar to those found in studies of children and adolescents with LD. Moderating variables are explored, and implications for practice and research are offered.

Control of surface topography in biomimetic calcium phosphate coatings.

The behavior of cells responsible for bone formation, osseointegration, and bone bonding in vivo are governed by both the surface chemistry and topography of scaffold matrices. Bone-like apatite coatings represent a promising method to improve the osteoconductivity and bonding of synthetic scaffold materials to mineralized tissues for regenerative procedures in orthopedics and dentistry. Polycaprolactone (PCL) films were coated with calcium phosphates (CaP) by incubation in simulated body fluid (SBF). We investigated the effect of SBF ion concentration and soaking time on the surface properties of the resulting apatite coatings. CaP coatings were examined by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectrometry (FTIR), and energy dispersive X-ray spectrometry (EDX). Young's modulus (E(s)) was determined by nanoindentation, and surface roughness was assessed by atomic force microscopy (AFM) and mechanical stylus profilometry. CaP such as carbonate-substituted apatite were deposited onto PCL films. SEM and AFM images of the apatite coatings revealed an increase in topographical complexity and surface roughness with increasing ion concentration of SBF solutions. Young's moduli (E(s)) of various CaP coatings were not significantly different, regardless of the CaP phase or surface roughness. Thus, SBF with high ion concentrations may be used to coat synthetic polymers with CaP layers of different surface topography and roughness to improve the osteoconductivity and bone-bonding ability of the scaffold.

Cultural beliefs and coping strategies related to childhood cancer: the perceptions of South Asian immigrant parents in Canada.

The purpose of this study is to describe cultural beliefs and coping strategies related to dealing with childhood cancer identified through a qualitative study of the caregiving experiences of first-generation South Asian immigrant parents of children with cancer. A constructivist grounded theory approach was employed. Families with a child at least 6 months postdiagnosis were recruited from 5 Canadian pediatric oncology centers. In-depth semistructured interviews were conducted in English, Hindi, Punjabi, or Urdu with a sample of 25 South Asian parents. Analysis of interviews involved line-by-line coding and using the constant comparison method. The following 2 central themes related to culture and coping emerged: (a) cultural beliefs about childhood cancer being incurable, rare, unspeakable, and understood through religion and (b) parental coping strategies included gaining information about the child's cancer, practicing religious rituals and prayers, trusting the health care professionals, and obtaining mutual support from other South Asian parents. These cultural beliefs and coping strategies have important implications for health care providers to understand the variations in the perceptions of childhood cancer and coping in order to implement culturally sensitive health care services.

Collective motivation beliefs of early adolescents working in small groups.

This study examined collective efficacy, group cohesion, and group performance in 125 randomly assigned groups of older (mean age 13.45 years) and younger (mean age 11.41 years) early adolescents working on three cooperative tasks. Collective motivation significantly predicted performance, even after controlling for past performance and self-efficacy for the older but not the younger participants. For the older (but not the younger) participants, groups with high collective efficacy and group cohesion scored higher on performance tasks than groups with low collective efficacy and group cohesion. The results point to the emergence of collective motivation beliefs in early adolescence, consistent with theories of social and cognitive development. Implications for theory and suggestions for future research are discussed.

Cross-cultural invariance of the Academic Expectations Stress Inventory: adolescent samples from Canada and Singapore.

We provide further evidence for the two-factor structure of the 9-item Academic Expectations Stress Inventory (AESI) using confirmatory factor analysis on a sample of 289 Canadian adolescents and 310 Singaporean adolescents. Examination of measurement invariance tests the assumption that the model underlying a set of scores is directly comparable across groups. This study also examined the cross-cultural validity of the AESI using multigroup confirmatory factor analysis across both the Canadian and Singaporean adolescent samples. The results suggested cross-cultural invariance of form, factor loadings, and factor variances and covariances of the AESI across both samples. Evidence of AESI's convergent and discriminant validity was also reported. Findings from t-tests revealed that Singaporean adolescents reported a significantly higher level of academic stress arising from self expectations, other expectations, and overall academic stress, compared to Canadian adolescents. Also, a larger cross-cultural effect was associated with academic stress arising from other expectations compared with academic stress arising from self expectations.

Self-efficacy from the perspective of adolescents with LD and their specialist teachers.

This study used qualitative methodology to investigate the self-efficacy beliefs of early adolescents with learning disabilities (LD). We conducted a series of focus group interviews with 28 Grade 8 and 9 students with LD and individual interviews with 7 specialist LD teachers. Content analyses of the student and teacher data resulted in 2 a priori and 3 inductive themes: self-efficacy, calibration and levels of self-efficacy, students' self-awareness, attributions for failure, and problems and solutions. The students viewed themselves as low in self-efficacy and generally accurate in the calibration of their efficacy and performance, whereas the teachers viewed the students as overconfident about academic tasks. In contrast to the teachers, the students viewed verbal persuasion as a valued source of self-efficacy. Students attributed their failures to lack of effort, whereas their teachers attributed student failure to uncontrollable deficits. Problems and solutions related to student motivation were discussed from student and teacher perspectives.