Arithmetic results on orbits of linear groups

Let $p$ be a prime and $G$ a subgroup of $GL_d(p)$. We define $G$ to be $p$-exceptional if it has order divisible by $p$, but all its orbits on vectors have size coprime to $p$. We obtain a classification of $p$-exceptional linear groups. This has consequences for a well known conjecture in representation theory, and also for a longstanding question concerning 1/2-transitive linear groups (i.e. those having all orbits on nonzero vectors of equal length), classifying those of order divisible by $p$.Comment: slight revisions after referee's comment

A Sustained Dietary Change Increases Epigenetic Variation in Isogenic Mice

Epigenetic changes can be induced by adverse environmental exposures, such as nutritional imbalance, but little is known about the nature or extent of these changes. Here we have explored the epigenomic effects of a sustained nutritional change, excess dietary methyl donors, by assessing genomic CpG methylation patterns in isogenic mice exposed for one or six generations. We find stochastic variation in methylation levels at many loci; exposure to methyl donors increases the magnitude of this variation and the number of variable loci. Several gene ontology categories are significantly overrepresented in genes proximal to these methylation-variable loci, suggesting that certain pathways are susceptible to environmental influence on their epigenetic states. Long-term exposure to the diet (six generations) results in a larger number of loci exhibiting epigenetic variability, suggesting that some of the induced changes are heritable. This finding presents the possibility that epigenetic variation within populations can be induced by environmental change, providing a vehicle for disease predisposition and possibly a substrate for natural selection.This work was supported by the Australian Research Council (DP0771859) and the National Health and Medical Research Council (#459412, #635510)

Considering Physical Well-Being, Self-perceptions, and Support Variables in Understanding Youth Academic Achievement

The purpose of this study was to examine the relation between measures of students’ physical well-being and self-perception and their academic achievement. Specifically, we look at students’ social support for physical activity, physical activity perceptions, self-concept, self-efficacy, health behaviors, and cardiorespiratory fitness (as measured by the progressive aerobic cardiovascular endurance run [PACER] test). Students (n = 697 fifth graders) were surveyed at the beginning of the school year. A two-group path analysis revealed notable relationships between the predictor variables and proximal and distal outcomes, with some paths moderated by sex. One relationship that was significant for both sexes was cardiorespiratory fitness, as it was the only significant predictor of achievement. This effect was moderate to large for the female students (R2Math=36%; R2Read=15%) and small to large for the male students (R2Math=26%; R2Math=10%). These findings can be used to guide future research and educational prevention and intervention efforts

Social Support and Smoking Abstinence among Incarcerated Adults in the United States: A Longitudinal Study

Background: In the United States, tobacco use among prisoners is nearly three times that of the general population. While many American prisons and jails are now tobacco-free, nearly all inmates return to smoking as soon as they are released back into the community. Methods: To better understand the role that personal relationships may play in enabling return to smoking, we enrolled former-smokers who were inmates in a tobacco-free prison. Baseline assessments were conducted six weeks prior to inmates’ scheduled release and included measures of smoking prior to incarceration, motivation, confidence and plans for remaining quit after release. We also assessed global social support (ISEL) and a measure of social support specific to quitting smoking (SSQ). Smoking status was assessed three weeks after prison release and included 7-day point-prevalence abstinence validated by urine cotinine, days to first cigarette and smoking rate. Results: A diverse sample comprised of 35% women, 20% Hispanic, and 29% racial minorities (average age 35.5 years) provided baseline data (n = 247). Over 90% of participants provided follow up data at 3-weeks post-release. Prior to incarceration participants had smoked an average of 21.5 (SD = 11.7) cigarettes per day. Only 29.2% had definite plans to remain smoking-abstinent after release. Approximately half of all participants reported that “most” or “all” of their family (42.2%) and friends (68%) smoked, and 58.8% reported their spouse or romantic partner smoked. SSQ scores were not significantly predictive of smoking outcomes at three weeks, however, social support from family and friends were each significantly and positively correlated with motivation, confidence, and plans for remaining abstinent (all p values Conclusions: Inmates of smoke-free prisons have a head-start on being smoke-free for life. They have been abstinent well past the duration of nicotine withdrawal and have great financial incentive not to begin smoking again. However, this advantage may be offset by a lack of non-smoking role models among their family and friends, and perceived lack of support for remaining smoke-free. Trial Registration: ClinicalTrials.gov Identifier: NCT0168499

Academic and Psychosocial Outcomes of a Physical Activity Program with Fourth Graders: Variations Among Schools in Six Urban School Districts

The purpose was to examine academic achievement, school attachment, and peer acceptance before and after a comprehensive school-based physical activity program (CSPAP) with 378 children in 12 fourth-grade classrooms across six schools in primarily low-socioeconomic status (SES) districts of a large Midwestern metropolitan area. Both personal and normative rate of academic achievement improvement metrics were used. Overall, all students showed personal math and reading growth. However, effects varied by types of achievement indicator and comparison group, revealing noteworthy school-level demographic and implementation characteristics that are inextricably intertwined with program effectiveness and student growth. Implications, especially for minimizing generalizations, are significant

An ecological approach to understanding academic achievement: Considering intrapersonal, physical activity, and support variables

The purpose of this study was to examine the relation between measures of students’ physical well-being and self-perception and their academic achievement. Specifically, we look at students’ social support for physical activity, physical activity perceptions, self-concept, self-efficacy, health behaviors, and cardiorespiratory fitness (as measured by the PACER test). Students (n = 697 fifth graders) were surveyed at the beginning of the school year. A two-group path analysis revealed notable relationships between the predictor variables and proximal and distal outcomes, with some paths moderated by sex. One relationship that was significant for both sexes was cardiorespiratory fitness, as it was the only significant predictor of achievement. This effect was moderate to large for the female students (R_Math^2 = 36%; R_Read^2 = 15%) and small to large for the male students (R_Math^2 = 26%; R_Read^2 = 10%). These findings can be used to guide future research and educational prevention and intervention efforts

Physical Activity Change Through Comprehensive School Physical Activity Programs in Urban Elementary Schools

he impact of Comprehensive School Physical Activity Programs (CSPAPs) on urban children’s, educators’, and parents’ physical activity (PA) is relatively unknown. The purpose of this study was to explore overall changes in student, educator, and parent PA after an 8-month CSPAP-based program. This longitudinal, exploratory study implemented a CSPAP in 20 urban elementary schools, with six randomized for research. In-school PA was measured prepost for all fourth grade students using accelerometers. Parent and educator PA was self-reported using the IPAQ. RM-ANOVAs revealed significant prepost increases in minutes of student MVPA (P \u3c .001). Parents significantly increased PA (P \u3c .01) and although educators’ reported change in PA, it was not statistically significant (P = .50). This study provides unique information about the potential influence of one CSPAP on students’ overall PA, PA by individual context within the school, the differential PA patterns by race, and PA changes for educators and parents

Oncostatin M Binds to Extracellular Matrix in a Bioactive Conformation: Implications for Inflammation and Metastasis

Oncostatin M (OSM) is an interleukin-6-like inflammatory cytokine reported to play a role in a number of pathological processes including cancer. Full-length OSM is expressed as a 26 kDa protein that can be proteolytically processed into 24 kDa and 22 kDa forms via removal of C-terminal peptides. In this study, we examined both the ability of OSM to bind to the extracellular matrix (ECM) and the activity of immobilized OSM on human breast carcinoma cells. OSM was observed to bind to ECM proteins collagen types I and XI, laminin, and fibronectin in a pH-dependent fashion, suggesting a role for electrostatic bonds that involves charged amino acids of both the ECM and OSM. The C-terminal extensions of 24 kDa and 26 kDa OSM, which contains six and thirteen basic amino acids, respectively, enhanced electrostatic binding to ECM at pH 6.5–7.5 when compared to 22 kDa OSM. The highest levels of OSM binding to ECM, though, were observed at acidic pH 5.5, where all forms of OSM bound to ECM proteins to a similar extent. This indicates additional electrostatic binding properties independent of the OSM C-terminal extensions. The reducing agent dithiothreitol also inhibited the binding of OSM to ECM suggesting a role for disulfide bonds in OSM immobilization. OSM immobilized to ECM was protected from cleavage by tumor-associated proteases and maintained activity following incubation at acidic pH for extended periods of time. Importantly, immobilized OSM remained biologically active and was able to induce and sustain the phosphorylation of STAT3 in T47D and ZR-75-1 human breast cancer cells over prolonged periods, as well as increase levels of STAT1 and STAT3 protein expression. Immobilized OSM also induced epithelial–mesenchymal transition-associated morphological changes in T47D cells. Taken together, these data indicate that OSM binds to ECM in a bioactive state that may have important implications for the development of chronic inflammation and tumor metastasis