DNA binding properties of an HMG1-related protein from yeast mitochondria

The DNA binding properties of ABF2, an abundant protein found in the mitochondria of the yeast Saccharomyces cerevisiae have been examined in detail. ABF2 is closely related to the vertebrate high mobility group protein HMG1 and like HMG1, ABF2 will introduce negative supercoils into a relaxed, double-stranded circular DNA molecule in cooperation with a DNA topoisomerase. Additionally, ABF2 binds approximately 5-10 times more tightly to negatively supercoiled DNA than to relaxed circular or linear DNA. Although ABF2 binds to most random double-stranded sequences with roughly equal affinity, its binding within certain key regulatory regions is qualitatively quite different. First, ABF2 binding induces a distinct pattern of DNA bending within the chromosomal origin of DNA replication, ARS1. Second, ABF2 binding to all nuclear replication origins tested, in addition to a critical mitochondrial promoter and replication origin, is clearly nonrandom as visualized by DNase1 footprinting. Analysis of the sequences found within these regions as well as competition experiments with synthetic DNA molecules suggest that site-specific DNA binding may be accomplished by the phased distribution of short stretches of poly(dA), which exclude ABF2 binding. These patterns of ABF2 DNA binding suggest a role for the protein in genome organization and site-specific regulation of transcription or DNA replication

Rpd3l contributes to the DNA damage sensitivity of saccharomyces cerevisiae checkpoint mutants

DNA replication forks that are stalled by DNA damage activate an S-phase checkpoint that prevents irreversible fork arrest and cell death. The increased cell death caused by DNA damage in budding yeast cells lacking the Rad53 checkpoint protein kinase is partially suppressed by deletion of the EXO1 gene. Using a whole-genome sequencing approach, we identified two additional genes, RXT2 and RPH1, whose mutation can also partially suppress this DNA damage sensitivity. We provide evidence that RXT2 and RPH1 act in a common pathway, which is distinct from the EXO1 pathway. Analysis of additional mutants indicates that suppression works through the loss of the Rpd3L histone deacetylase complex. Our results suggest that the loss or absence of histone acetylation, perhaps at stalled forks, may contribute to cell death in the absence of a functional checkpoint.Cancer Research UK FC001066UK Medical Research Council FC001066Wellcome Trust FC001066European Molecular Biology Organization ALTF 263–2011European Research Council Advanced 669424-CHROMORE

YOUTH SOCCER COACHING METHODOLOGIES’ IMPACT ON ENJOYMENT OF THE GAME AND RETENTION

According to the Sports & Fitness Industry Association (SFIA, 2018), at least 4,420,000 children between the ages of 6–12 and 2,454,000 children between the ages of 13–17 participate in outdoor soccer in the United States. Arguably, their coaches have a significant impact on these children’s development. The purpose of this study was to evaluate coaching methods in soccer and their relationship to youth players’ enjoyment of the game and retention rates. The sample consisted of youth soccer players from the New York metropolitan area. This study adds to the growing literature on youth sports and demonstrates that coaches have a significant impact on outcomes such as enjoyment of the sport, increases in self-confidence, and motivation to remain in the sport. This study was used quantitative analysis and the Leadership Scale for Sports (LSS), designed by Chelladurai and Saleh (1978, 1980), with the goal of assessing athletes’ perceptions of coaches’ leadership styles and behaviors. This instrument assesses coaches’ leadership style along five dimensions: training and instruction, autocratic behavior, democratic behavior, social support, and positive feedback (Chelladurai & Saleh, 1980, as cited in Wood, 2008). It is important for coaches to understand young athletes’ motives for continued participation. Creating a positive environment within a team and at training sessions can have a lasting impact on overall enjoyment and, ultimately, on retention of team members. The findings of this research provide additional support for specific coaching methodologies, such as including players in the decision-making process, providing specific positive feedback and encouragement, creating realistic expectations, providing social time for teammates to make friends, and creating an environment that reduces fear of trying new skills

Impact of Interviewers’ Personal Bias on Hiring of Law Enforcement Applicants

Individuals posing a risk to the community who pass preemployment interviews represent a problem for law enforcement departments and their communities. The purpose of this phenomenological study was to explore the shared experiences of participants regarding hiring biases that may exist among individuals tasked with interviewing law enforcement applicants. Argyris’s organizational learning theory provided the framework for the study. Data were collected from semistructured interviews with 4 participants who had experience interviewing applicants for placement in a law enforcement department.Data were analyzed to identify themes.Biases included participants’ interpretation of applicants’ appearance, body language, ability to handle stress/pressure, preparedness for the interview, problem-solving ability, and responses to questions that matched preselected answers applicant interviewers require for scoring purposes.Findings may be used to improve the law enforcement hiring process and to enhance relationships between law enforcement departments and their communities

Development of Circadian Sleep-Wakefulness Rhythm in a Healthy Boy Gauged by Circadian Quotients

The circadian quotient, briefly CQ, serves to estimate the prominence of a rhythm with a period of about 24 hours. The CQ may be computed from so-called variance spectrum analysis, among other procedures ( 1) . Computational details and some applications have been discussed earlier (1 , 2). We wish to illustrate herein the use of the CQ for gauging the development of a circadian sleep-wakefulness rhythm in the senior author\u27s first-born child, FAR, also documented in general terms, elsewhere ( 3)