Search results for "FITNESS"
showing 10 items of 1020 documents
Balancing selection maintains polymorphisms at neurogenetic loci in field experiments
2017
Most variation in behavior has a genetic basis, but the processes determining the level of diversity at behavioral loci are largely unknown for natural populations. Expression of arginine vasopressin receptor 1a (Avpr1a) and oxytocin receptor (Oxtr) in specific regions of the brain regulates diverse social and reproductive behaviors in mammals, including humans. That these genes have important fitness consequences and that natural populations contain extensive diversity at these loci implies the action of balancing selection. In Myodes glareolus, Avpr1a and Oxtr each contain a polymorphic microsatellite locus located in their 5′ regulatory region (the regulatory region-associated microsatel…
Fitness costs of increased cataract frequency and cumulative radiation dose in natural mammalian populations from Chernobyl
2015
AbstractA cataract is a clouding of the lens that reduces light transmission to the retina and it decreases the visual acuity of the bearer. The prevalence of cataracts in natural populations of mammals and their potential ecological significance, is poorly known. Cataracts have been reported to arise from high levels of oxidative stress and a major cause of oxidative stress is ionizing radiation. We investigated whether elevated frequencies of cataracts are found in eyes of bank voles Myodes glareolus collected from natural populations in areas with varying levels of background radiation in Chernobyl. We found high frequencies of cataracts in voles collected from different areas in Chernob…
Male relatedness and familiarity are required to modulate male-induced harm to females in
2017
Males compete over mating and fertilization, and often harm females in the process. Inclusive fitness theory predicts that increasing relatedness within groups of males may relax competition and discourage male harm of females as males gain indirect benefits. Recent studies in Drosophila melanogaster are consistent with these predictions, and have found that within-group male relatedness increases female fitness, though others have found no effects. Importantly, these studies did not fully disentangle male genetic relatedness from larval familiarity, so the extent to which modulation of harm to females is explained by male familiarity remains unclear. Here we performed a fully factorial des…
Physical Fitness and Hormonal Profile During an 11-Week Paratroop Training Period.
2015
Physical fitness and serum hormone concentrations have been shown to change during military training. The purpose was to examine these chronic changes in paratroopers (n = 52 male conscripts) during an 11-week training period, including acute changes induced by strenuous 5-day military field training. Hormonal profiles, body mass, maximal strength, muscle endurance, and 12-minute running test were assessed at several time points during paratrooper training. In the latter part of the training period, conscripts were involved in strenuous military field training (5 days). At week 7, during specialized military training period, aerobic performance decreased (3,146 ± 163 m) but recovered back t…
Use of the Perceived Physical Competence Scale with Adolescents with Disabilities
1995
The construct validity and reliability of the 1987 Perceived Physical Competence Scale of Lintunen were examined to assess the applicability of the instrument for use with adolescents with disabilities. Subjects were 51 girls and 34 boys ( M age = 15.1 yr.) from several schools in central Finland. Principal component factor analysis with varimax rotation yielded the same two factors for adolescents with disabilities as reported for nondisabled adolescents in the related literature. Cronbach alphas for the two factors were .89 and .56. It was concluded that the scale is an appropriate measure for adolescents with disabilities. Statistical analysis indicated no gender differences for adolesc…
The relationship between physical activity and physical self-esteem in adolescents: the role of physical fitness indices.
2013
The aim of this study was to investigate if physical fitness (strength/power, endur ance, flexibility and coordination) mediates the cross-sectional relationship between physical activity and physical self-perception (athletic competence and physical appearance) in a sample of 15-year old adolescents. We wanted to investigate the relative strength of each indirect effect. The present data are taken from two waves of a larger data collection for the project “Youth in Balance”, and was collected in the autumn of 2005 (N = 1207) and 2008 (N = 632). A total of 1839 students (889 girls and 950 boys) from 12 schools in Kristiansand took part. A bias-corrected bootstrapping technique was used to e…
Finnish late adolescents’ physical activity during COVID-19 spring 2020 lockdown
2021
Background Physical activity (PA) is recognised as one of the leading and effective strategies to prevent non-communicable diseases that boosts the immune system to fight against diseases. Closures of schools, sport clubs and facilities because of COVID-19 reduced the opportunities to participate in PA. We aimed to examine physical activity levels of late adolescents, the contexts to be physical active and its changes during the spring 2020 lockdown. Methods A national representative sample of late adolescents in general upper secondary school (n = 2408, females = 64%, mean age = 17.2y, SD = 0.63) completed self-report online surveys on PA behaviours between March and June 2020. Multinomina…
Developmental associations of accelerometer measured moderate-to-vigorous physical activity and sedentary time with cardiorespiratory fitness in scho…
2022
Objectives This study examined the developmental associations of accelerometer-based moderate-to-vigorous physical activity (MVPA) and sedentary time (ST) with cardiorespiratory fitness (CRF) in schoolchildren. Design A three-year follow-up study. Methods Participants were 446 (girls 57 %) Finnish children (M = 11.26 ± 0.32 years) from 17 randomly selected public schools in Finland. Accelerometer-based MVPA and ST were assessed using waist-worn activity monitors and CRF using the 20 m shuttle run test at four measurement points from 2017 to 2020. The developmental associations were tested using the Random Intercept Cross-Lagged Panel Model (RI-CLPM) reflecting MVPA, CRF, and ST overall leve…
Is low cardiorespiratory fitness a feature of metabolic syndrome in children and adults?
2022
Objectives Cardiorespiratory fitness (CRF) has been inversely associated with risk of cardiometabolic diseases. However, there are no studies comparing the independent associations of CRF scaled by body size and composition using different approaches with cardiometabolic risk factors between children and adults. We therefore investigated these associations in children and adults using same measures for CRF and cardiometabolic risk factors. Design Cross-sectional. Methods A total of 352 children (47.2 % girls) and 572 men were included in the study. Peak oxygen uptake (V̇O2peak) was measured during a maximal exercise test on a cycle ergometer and was scaled by total body mass (BM−1), total f…
The assessment of scales of frailty and physical performance improves prediction of major adverse cardiac events in older adults with acute coronary …
2019
Abstract Background The number of older adults admitted to hospital for acute coronary syndrome (ACS) has increased worldwide. The aim of this study was to determine which scale of frailty or physical performance provides incremental improvements in risk stratification of older adults after ACS. Methods A prospective cohort of 402 older (≥70 years) ACS patients were enrolled. Data about baseline characteristics, Global Registry of Acute Coronary Events (GRACE), and Thrombolysis in Myocardial Infarction (TIMI) risk scores were collected. Before hospital discharge, seven scales of frailty and physical performance were measured. The 1-year occurrence of adverse events (cardiac death, reinfarct…