Truman State University

Leadership transitions are a fact of organizational life, yet the impact of successors' leadership behavior on organizational outcomes is little understood. Building on change readiness, uncertainty management, and romance of leadership theory and research, we propose a novel theory describing the distinctive effects of successors' versus incumbents' leadership behavior in driving change in collective engagement and organizational performance. We theorize that when employees perceive a great need for organizational change, successors' vision communication and coaching are more likely than incumbents' to yield improvements in collective engagement and organizational performance. But when employees perceive little need for change, successors' vision communication and coaching are more likely than incumbents' to yield declines. To test our model, we conducted a longitudinal, quasi-experimental study of principal succession in a sample of 113 U.S. elementary schools. As predicted, when employees perceived a great need for change, successors' coaching sparked gains in collective engagement and organizational performance. When employees perceived little need for change, successors' coaching backfired, spurring declines in collective engagement and organizational performance. As predicted, the effects of incumbents' coaching were muted. Finally, contrary to our predictions, neither successors' nor incumbents' vision communication drove change in collective engagement and performance. Our theory and findings illuminate the distinctive risks and benefits of successors' leadership behavior in driving change in collective engagement and organizational performance. For good and for bad, successors' coaching changes their organizations in ways that incumbents' leadership does not. (PsycInfo Database Record (c) 2026 APA, all rights reserved).

Abstract Background Innovations in Artificial Intelligence (AI) and Virtual Reality (VR) are driving transformative changes in medical imaging and education by enabling automated segmentation and immersive visualization. Traditional anatomy and imaging instruction often lack spatial interactivity, limiting comprehension and diagnostic reasoning. This study introduces VISTA-MED, an integrated AI-VR platform designed to enhance medical imaging education through real-time MRI visualization and segmentation. Methods The system employs the nnU-Net architecture for automated segmentation of brain tumor regions using the BRATS2020 dataset. Preprocessing included bias field correction, image registration to the MNI152 template, and noise reduction. Segmentation outputs were converted into 3D-compatible formats and integrated into a Unity-based VR environment supporting interactive exploration of anatomical structures. Performance was evaluated using Dice coefficient, Intersection over Union (IoU), and precision-recall analysis. Results The segmentation model achieved a mean Dice score of 0.914, indicating high overlap between predicted masks and ground truth annotations. IoU values were consistent with Dice scores, confirming accurate delineation of tumor boundaries. Internal testing validated smooth rendering and stable frame rates in the VR environment, enabling real-time interaction without noticeable latency. Qualitative assessment confirmed anatomical fidelity of AI-generated masks. Conclusion VISTA-MED demonstrates the technical feasibility of combining AI-driven segmentation with immersive VR visualization for medical imaging education. This integration enhances spatial understanding and diagnostic reasoning, addressing limitations of traditional anatomy instruction. Future work will focus on usability studies, scalability, and educational impact assessment to support broader adoption in clinical and academic settings.

ABSTRACT To better support teachers and reduce attrition, it is important to examine the complex and evolving relationship between the teaching tasks and teacher performance in Physical Education. Guided by self-efficacy theory and a model of career progression, this longitudinal study aimed to analyze the teaching performance and efficacy of early-career physical educators over their first 5 years of teaching. Teaching performance was measured through direct classroom observation using Academic Learning Time in Physical Education (ALT-PE) and Qualitative Measures of Teaching Performance Scale (QMTPS). Teacher efficacy was assessed using validated self-report instruments, the Physical Education Teaching Efficacy Scale (PETES) and the Self-Evaluation of Teacher Effectiveness Questionnaire in PE (SETEQ-PE), alongside a demographic survey. Data collection occurred two to three times annually. Participants included five to ten teachers from two states. PETES visual analyses of descriptive graphs showed positive trends with RM-ANOVA confirming statistically significant growth over time. SETEQ-PE scores also improved, though not significantly. Similarly, ALT-PE data trended in a positive direction for motor-appropriate student engagement and demonstrated significant improvements over time. However, QMTPS scores indicated a downward trend with no significant changes. Interobserver agreement exceeded 90% across observations. Over a 5-year period, teachers exhibited minor improvements in teaching efficacy and the amount of motor appropriate student engagement. Teachers who feel empowered are likely to maintain higher levels of teaching efficacy, and positive career cycle progression requires effective mentoring and relevant professional development to minimize the factors leading to teacher attrition and drop out.

The United States military continues to search for a fair and equitable procedure to assess body composition among its active-duty personnel. The need remains for a simple yet accurate assessment tool to alleviate the need for expensive laboratory equipment and extensive time commitment. Recently a new waist circumference technique was proposed to estimate %fat in military men and women. Thus far this approach has not been cross validated to assess its applicability in young men. PURPOSE: To evaluate the accuracy of a new waist circumference equation to estimate %fat in college football athletes. METHODS: Members of a college football team (n = 120, age = 20.7 ± 1.3 yrs, height = 181.7 ± 6.0 cm, weight = 100.0 ± 17.6 kg) were measured for %fat using dual-energy X-ray absorptiometry (DXA). Waist circumference (WC) was measured at the level of the umbilicus and applied with body weight in the new equation to estimate %fat. RESULTS: Cross-validation of the new equation significantly underpredicted %fat (18.8 ± 5.6%) compared to DXA (21.6 ± 7.7%) despite a high correlation between the values (r = 0.84, p < 0.001). Using current military %fat cut-off criteria, 36% of these men would have been denied military service using DXA while 26% would have been denied military service by the prediction equation. DXA and the WC equation agreed on 20% of the participants. CONCLUSION: These results suggest a newly developed predicted equation derived from DXA for military screening tends to underpredict %fat in a sample of physical fit college football players. Further cross-validating on a separate sample of military personnel using DXA needs to be done prior to adopting the new equation. In addition, a reassessment of the %fat scale for acceptable military service may need to be done since DXA typically presents higher %fat values than all other techniques.

ABSTRACT In the early 1960s, as relations between Cuba and the United States rapidly deteriorated and edged dangerously close to a nuclear conflagration with the Soviet Union, several Latin American countries resisted aligning with the United States in its efforts to isolate and overthrow the revolutionary Cuban government. Leaders of these countries advocated for mediation, proclaiming that they favored a peaceful resolution of conflict in an international venue such as the United Nations rather than resorting to armed force. Despite considerable pressure from the United States to adopt a more belligerent stance towards Cuba, Ecuador was one of those countries that initially stood firm in its pursuit of a diplomatic solution. Ecuador declared itself to be a land of peace and urged mediation. By inserting itself into much larger international conflicts, this small, geopolitically marginalized country played an outsized role in pressing for a peaceful resolution to avert potentially catastrophic consequences. At first, Ecuador's proclamations may appear surprising given stereotypical assumptions that Latin America was a region rife with violent civil strife. In reality, leaders drew on a long tradition of policies of nonintervention that advocated for amicable compromises to problems. This essay explores the unique complexities of Ecuador's diplomatic efforts during a critical period of the Cold War and its commitment to principles of regional stability and sovereignty. By extension, it highlights a broader tradition in Latin America of prioritizing peaceful and diplomatic resolutions to international conflicts, thereby illuminating a lesser‐known aspect of the region's history.

ABSTRACT This article examines how ostensibly neutral newspaper coverage enabled the Ku Klux Klan’s growth and legitimacy in Kirksville, Missouri, during the 1920s. Through a detailed analysis of the Kirksville Daily Express and Weekly Graphic, it argues that local journalism not only reflected community biases but also actively contributed to the normalization of Klan ideology. Rather than confronting the Klan’s racism and nativism, the Kirksville press framed its activities as patriotic spectacle, offered promotional coverage, sold advertising space, and protected members’ anonymity. Appearances of neutrality masked an underlying ideological alignment with white Protestant supremacy, mirroring patterns found in Southern Jim Crow journalism. By treating the Klan as a civic actor instead of a threat, the press reinforced the social and political status quo. The study highlights how journalistic norms of objectivity can obscure press alignment with exclusionary movements—an insight with continuing relevance for contemporary debates over media responsibility and political framing.

The Cas9 nuclease has become central to modern methods and technologies in synthetic biology, largely due to the ease in which it can be targeted to specific DNA loci via guide RNAs (gRNAs). Reports vary widely on the actual specificity of this targeting, with some studies observing 60% of gRNAs possessing no activity against the genome, while there is a general assumption in the E. coli community that inactive gRNAs are rare. To resolve these contradictions, we evaluated the activity of nearly 500,000 unique gRNAs in the E. coli K12 MG1655 genome. We show that the overwhelming majority of unique gRNAs are functional (at least 93%) while only 0.3% are nonfunctional. These nonfunctional gRNAs tend to exhibit strong spacer self-interaction, leading to the development of a simple set of gRNA design rules for bacteria. Finally, this work provides the greater microbial synthetic biology community a set of nearly half a million sgRNA spacers that have been empirically evaluated in vivo which will expedite future biological engineering projects.

Love and Loss (2025), dir.