Interactions between subunits a and b in the rotary ATP synthase as determined by cross-linking

The interaction of the membrane traversing stator subunits a and b of the rotary ATP synthase was probed by substitution of a single Cys into each subunit with subsequent Cu2+ catalyzed cross-linking. Extensive interaction between the transmembrane (TM) region of one b subunit and TM2 of subunit a was indicated by cross-linking with 6 Cys pairs introduced into these regions. Additional disulfide cross-linking was observed between the N-terminus of subunit b and the periplasmic loop connecting TM4 and TM5 of subunit a. Finally, benzophenone-4-maleimide derivatized Cys in the 2–3 periplasmic loop of subunit a were shown to cross-link with the periplasmic N-terminal region of subunit b. These experiments help to define the juxtaposition of subunits b and a in the ATP synthase

DEVELOPING A PRINCIPAL INDUCTION PROGRAM FOR CRAVEN COUNTY SCHOOLS

The demands of principals have increased drastically over the years and principals are overwhelmed as they accept the responsibility for an entire school. With an emphasis on performance and accountability and realizing that the principal’s contribution to student learning is second only to the teacher, school districts are seeking tools to develop highly effective principals. This study investigated the problem of too few experienced administrators in Craven County Schools. The problem of practice grew out of concern from Superintendent Dr. Lane Mills and the district leadership team as they reviewed the experience levels of the principals. The questions examined were: 1. Using the continuous improvement model, what is the comprehensive design of a Principal Induction Program to prepare school leaders for effective leadership in Craven County? 2. Based on the literature review, anecdotal notes, surveys, emotional intelligence test, and interviews, what components are deemed essential to be a highly qualified principal in Craven County? The results of the data collected found: (1) The principalship requires a multidimensional leader (2) Principals of various experience levels perceive themselves differently than others; and (3) Principals support should include a multifaceted approach through individualized and cohort based activities. Findings from this research reinforced the importance of a Craven County Principal Induction Program. The data collected will be used in preparing Craven County Schools’ administrators for the work of a twenty-first century principal, one who focuses on learning and balances the managerial responsibilities. Z. Smith Reynolds recognized the Craven County Schools commitment to leadership and the district was awarded a grant of ninety thousand dollars to ensure that support for their leaders continue

Mechanically Induced Chromatin Condensation Requires Cellular Contractility in Mesenchymal Stem Cells

This work was supported by the National Institutes of Health (R01 AR056624, R01 EB02425, T32 AR007132, and P30 AR050950). Additional support was provided by a Montague Research Award from the Perelman School of Medicine and a University of Pennsylvania University Research Foundation Award

Increasing Caregiver Knowledge of Water Safety Through an Evidence-Based Presentation

Purpose. The purpose of this quality improvement project was to determine if providing evidence-based education on drowning risk and water safety strategies to pediatric caregivers of children ages 1 to 4 years would lead to increased caregiver knowledge of pediatric drowning risk and water safety at Cigna Medical Group Paseo.Background. Drowning remains the leading cause of death by unintentional injury in children ages 1 to 4 years in the United States. Although there has been a decrease in drowning fatalities nationally, rates for Arizona resident children under the age of 5 years have increased from 3.3 deaths per 100,000 in 2019 to 6.6 deaths per 100,000 in 2020. Drowning is a preventable injury that requires multiple layers of protection. Providing caregivers with frequent and high-quality education on water safety strategies is a crucial step toward decreasing the risk of drowning in the pediatric population. Methods. This project utilized a quantitative, pretest/posttest, single-group design to assess for knowledge change before and after a short evidence-based educational intervention provided to caregivers of children ages 1 to 4 years. Participants were recruited from a convenience sample of 5 caregivers who presented to Cigna Medical Group Paseo. Results were analyzed using descriptive statistics and a paired t-test. Results. A total of 5 eligible caregivers chose to participate in the educational intervention. All 5 participants completed the pretest, educational presentation, and posttest. Data analysis revealed a statistically significant increase in caregiver knowledge of drowning risk and water safety strategies following the intervention. All participants reported that they planned to implement the water safety strategies presented and found the intervention to be useful, clear, and relevant to their role as a caregiver. Conclusion. The evidence-based presentation effectively increased caregiver knowledge of drowning risk and water safety interventions as evidenced by an increase in scores from the pretest to the posttest. The positive outcomes of this project show that this type of educational intervention results in increased caregiver knowledge and may potentially lead to decreased drowning risk for young children at the clinic site

A chemiosmotic mechanism of symport

Lactose permease (LacY), a paradigm for the largest family of membrane transport proteins, catalyzes the coupled translocation of a galactoside and an H(+) across the Escherichia coli membrane (galactoside/H(+) symport). Initial X-ray structures reveal N- and C-terminal domains, each with six largely irregular transmembrane helices surrounding an aqueous cavity open to the cytoplasm. Recently, a structure with a narrow periplasmic opening and an occluded galactoside was obtained, confirming many observations and indicating that sugar binding involves induced fit. LacY catalyzes symport by an alternating access mechanism. Experimental findings garnered over 45 y indicate the following: (i) The limiting step for lactose/H(+) symport in the absence of the H(+) electrochemical gradient (∆µ̃(H)+) is deprotonation, whereas in the presence of ∆µ̃(H)+, the limiting step is opening of apo LacY on the other side of the membrane; (ii) LacY must be protonated to bind galactoside (the pK for binding is ∼10.5); (iii) galactoside binding and dissociation, not ∆µ̃(H)+, are the driving forces for alternating access; (iv) galactoside binding involves induced fit, causing transition to an occluded intermediate that undergoes alternating access; (v) galactoside dissociates, releasing the energy of binding; and (vi) Arg302 comes into proximity with protonated Glu325, causing deprotonation. Accumulation of galactoside against a concentration gradient does not involve a change in K(d) for sugar on either side of the membrane, but the pK(a) (the affinity for H(+)) decreases markedly. Thus, transport is driven chemiosmotically but, contrary to expectation, ∆µ̃(H)+ acts kinetically to control the rate of the process