Observation of Aubry transition in finite atom chains via friction

The highly nonlinear many-body physics of a chain of mutually interacting atoms in contact with a periodic substrate gives rise to complex static and dynamical phenomena, such as structural phase transitions and friction. In the limit of an infinite chain incommensurate with the substrate, Aubry predicted a structural transition with increasing substrate potential, from the chain's intrinsic arrangement free to slide on the substrate, to a pinned arrangement favoring the substrate pattern. To date, the Aubry transition has not been observed. Here, using a chain of cold ions subject to a periodic optical potential we qualitatively and quantitatively establish a close relation between Aubry's sliding-to-pinned transition and superlubricity breaking in stick-slip friction. Using friction measurements with high spatial resolution and individual ion detection, we experimentally observe the Aubry transition and the onset of its hallmark fractal atomic arrangement. Notably, the observed critical lattice depth for a finite chain agrees well with the Aubry prediction for an infinite chain. Our results elucidate the connection between competing ordering patterns and superlubricity in nanocontacts - the elementary building blocks of friction.Comment: 5 pages, 4 figure

The Acute and Chronic Muscle Adaptations Following six weeks of No Load and Traditional High Load Resistance Training

Muscle growth is postulated to occur through mechanisms initiated by local muscle tension. This appears to be true, independent of the external load, provided sufficient tension is achieved. PURPOSE: The purpose of this study was to remove the influence of an external load and compare the acute and chronic muscle adaptations of “No Load” training to traditional High Load training. METHODS: Thirteen participants completed six weeks of thrice weekly unilateral elbow flexion exercise. Using a within subject design, each arm was designated to either the No Load or the High Load (70% one repetition maximum) condition. The No Load condition had the participants repeatedly contract through the full range of motion without the use of body weight or an external load. Muscle size, strength and endurance were measured pre and post training. Acute muscle responses of muscle swelling, fatigue and activation were measured within the training study. RESULTS: Anterior muscle thickness increased pre to post training with no differences between conditions 50% [pre: 2.7 (0.8) vs. post: 2.9 (0.7) cm], 60% [pre: 2.9 (0.7) vs. post: 3.1 (0.7) cm] or 70% [pre: 3.2 (0.7) vs. post: 3.5 (0.7) cm] sites. There was a significant condition x time interaction for one repetition maximum (p=0.017), with High Load (+2.3 kg) increasing more than the No Load condition (+1 kg). For the acute responses, there was a main effect of time for muscle fatigue [pre 40.8 (13.2) vs. post 36 (9.1) Nm p=0.037] and muscle swelling [pre 3.5 (0.6) vs. post 3.8 (0.6) cm, p\u3c0.001]. For the biceps brachii EMG amplitude, the High load condition was greater than the No Load condition for the last three repetitions (p=0.019). Regarding the triceps brachii EMG amplitude, the No Load condition was significantly greater than the High Load condition for the first three and the last three repetitions (p?0.001). Conclusion: Based on these results, muscle growth can occur independent of the external load provided that sufficient local tension is applied to the muscle

UNDERSTANDING PERSPECTIVES OF CLINICAL AND NON-CLINICAL HEALTHCARE ADMINISTRATORS ON CULTURE AND DIVERSITY IN THE HEALTHCARE WORKPLACE

The racial and ethnic composition of the U.S. population is becoming increasingly more diverse. The 2010 U.S. Census reported a 29% increase in minority groups other than non-Hispanic Whites. In response to these changing demographics, healthcare organizations have struggled to keep pace with these trends in their hiring of a diverse staff. Healthcare leaders appear to be lagging in their efforts to make adequate changes to increase diversity in their organizations. What factors may be contributing to this inequity? One possible explanation is a limited knowledge of healthcare leaders regarding culture and diversity within the workplace. To this end, this study explores the individual cultural intelligence of clinical and non-clinical administrative healthcare leaders, while also shedding light on leadership perspectives of cultural metrics in the workplace. Initial conversations with university-based healthcare leaders shed light on the need to understand the value placed on creating a diverse teams and the role that cultural understanding plays in understanding and working with others who are different from ourselves

Organizational Change Within Christian Higher Education Institutions and the Reactions of Faculty

Christian higher education in the United States is experiencing frequent transformational organizational change that is impacting faculty. Researchers have asserted that frequent, second-order organizational change correlates with interpersonal conflict, and conflict is associated with counterproductive work behaviors (CWBs). These associations between change, conflict, and negative work behavior are important to understand as faculty actions could significantly impact change efforts. Because of the context of Christian higher education, this study was designed to determine if faculty organizational identification influenced the correlations of the variables. It specifically utilized a cross-sectional survey design to assess faculty (N = 267) perceptions of organizational change, interpersonal conflict, CWB, and organizational identification at 5 faith-based universities. Organizational change had a statistically significant positive association with interpersonal conflict, and conflict had a statistically significant positive correlation with CWBs. Organizational identification did not influence these correlations but was found to have a statistically significant negative relationship with interpersonal conflict and CWBs. A model was proposed using an open systems theory perspective that reflected the relationship between all the variables. The findings suggested that leaders in Christian higher education must consider the systemic effects of organizational change as they implement change initiatives

Comparative analysis of Cu(InGa)Se2 solar cells

2016 Spring.Includes bibliographical references.Cu(InGa)Se2, often abbreviated CIGS, photovoltaics have proven to be a commercially viable solar-energy conversion technology. Diverse processes have been employed in the manufacture, with varying end products, most resulting in high efficiency. A collaborative project was undertaken with several CIGS labs and industrial partners to explore the different electrical and spatial characteristics of CIGS solar cells relative to one another. Characterization methods utilized include, current-voltage measurements, quantum efficiency, capacitance-frequency and capacitance-voltage, electroluminescence, light-beam-induced current and Auger profling. Specific parameters for each cell were extracted from the measurements. Together the methods used are a tool for understanding device performance and optimization. Efforts were made to identify strengths, similarities and differences and to connect processing details with observed characteristics

Invisible Woman? Narratives of Black Women Leaders in Southeastern Two-Year Colleges

This narrative research study explored the experiences of two Black women executive-level leaders who started their careers within higher education, including two-year technical colleges located in the Southeast during the pivotal sociopolitical moments that occurred during the1960s to the1980s. The stories of these women revealed their perceptions of the barriers they faced as well as the opportunities they received for career advancement as their careers evolved parallel to the development of the technical college system itself. Qualitative procedures, including semi-structured interviews and a combined narrative analysis and analysis of narratives interpretative framework (Connelly & Clandinin, 2006; Creswell, 2009; Kramp, 2004; Polkinghorne, 1995, as cited in Kramp, 2004, and in Creswell, 2007; and Roberts, 2002), illuminated a richly descriptive and complex perspective of these women\u27s lived experiences. The theoretical frameworks of critical race theory and Black feminist theory - viewed through the historical lens of Southern racial politics - served as the foundation for the research questions. The guiding research question that framed this study was: What are the experiences of Black women executive-level leaders in Southeastern two-year colleges? The secondary questions were: How do Black women leaders\u27 constructed realities regarding social, theoretical, political, spiritual, familial, and other factors influence the participants\u27 leadership development and their leadership style or approach? How did the civil rights and women\u27s rights movements influence Black women leaders\u27 career choices and desire for advancement? How do these Black women leaders perceive challenges to their career advancement? How do they describe the pivotal successes of their careers? How do they perceive the future for Black women who aspire to leadership within two-year colleges in the Southeast? In the moving and deeply personal stories of their lives, two Black women leaders shared concerns about the continued need for mentors to help Black women in developing fully their leadership potential; their commitment to enhancing and increasing diversity and awareness on their campuses; and their recognition of the dynamics of race and how race plays out in their lives, their professional roles, and in their perceptions of others and of themselves. The women also shared a commitment to \u27pulling all of the strengths together\u27 for successful team building; their belief in the importance of faith and spirituality in maintaining a balanced perspective on work and life; and the joy they both found in their leadership lives when they embraced the mantra that \u27what\u27s for you is for you,\u27 so it\u27s important to always \u27put [yourself] in the way of a blessing.\u27 This study underscores the importance of exploring Black women\u27s perceptions of their individual and collective leadership experiences within scholarly discourse, and recommendations will be made for future studies based on the implications of the study\u27s findings. Keywords: Black or African-American women administrators or leaders, two-year technical and community colleges, barriers, opportunities, career development and advancement, transformational leadership, postheroic leadership, servant leadership, critical race theory, Black feminist theory, narrative inquiry or narrative researc

Vitamin D Administration for Treatment of Depression in Women

Depression is a mood altering state which can be characterized by feelings of sadness that can affect thoughts, daily activities, emotions, physical health and even behavior of an individual, most often affecting women (National Alliance on Mental Illness, 2014, para 1 ). In the United States, depression has affected millions of the U.S. population (Peckofer et al, 2010). It is important that we focus on both the disease itself and depression related morbidity and mortality. A large number of depressed patients will suffer from a depressive crisis. These crises\u27 can lead to sclf-inf1icted injuries, worsening of the individual \u27s medical conditions or even death. Treatment is critical (K wasky & Groh, 2012). With the large number of individuals this disease affects, a treatment is essential. The neural pathways and brain chemistry associated with depression is still poorly understood . Vitamin Dis found to be involved in many brain activities and functions required in an individual\u27s life (Anglin et al , 2013). The brain activates vitamin D and without proper function of the brain, vitamin D deficiency can become a large problem (Jorde et al., 2008). Decreased vitamin D levels have been shown to cause cognitive dysfunction, depressive symptoms, and lead to anxiety. Decreased levels of Vitamin Dare often seen with individuals who are obese or overweight (Jorde et al., 2008). This independent study explored the option of treating depression with vitamin D and whether or not this treatment was found to be effective. The information from this independent study was research, compiled and presented to staff in an outpatient behavioral health unit in hopes of finding an alternative treatment option for the treatment of depression. When the presentation was done and questions were answered, it was decided that further studies need to be done on the efficacy of vitamin D for the treatment of depression at higher levels, as there was not enough sufficient evidence at this tim