Ytterbium divalency and lattice disorder in near-zero thermal expansion YbGaGe

While near-zero thermal expansion (NZTE) in YbGaGe is sensitive to stoichiometry and defect concentration, the NZTE mechanism remains elusive. We present x-ray absorption spectra that show unequivocally that Yb is nearly divalent in YbGaGe and the valence does not change with temperature or with nominally 1% B or 5% C impurities, ruling out a valence-fluctuation mechanism. Moreover, substantial changes occur in the local structure around Yb with B and C inclusion. Together with inelastic neutron scattering measurements, these data indicate a strong tendency for the lattice to disorder, providing a possible explanation for NZTE in YbGaGe.Comment: 4 pages, 4 figure, supplementary inf

Differences in health-related physical fitness and academic school performance in male middle school students in Qatar:a preliminary study

This study examined the differences in the level of physical fitness and academic performance among male middle-school children based on different body status categories. A total of 69 male children [age: 12.4 ± 0.7 years; body mass: 58.5 ± 7.2 kg; height: 1.62 ± 0.09 m; and body mass index (BMI): 22.4 ± 3.3 kg/m 2 ] participated and were divided into BMI age-adjusted groups (i.e., lowest, middle, and highest BMI). Height, mass, BMI, stork test of static balance, 10 and 15 m sprint as an indicator for speed, hand-grip strength test, agility T-half test, medicine ball throw (MBT), and the Yo-Yo Intermittent Recovery Test level 1 (Yo-Yo IR1) were assessed. School records were retrieved for grade point averages (GPA) of mathematics, science, and Arabic. We found significant group differences regarding anthropometric (height: η p 2 = 0.24, mass: η p 2 = 0.33, and BMI: η p 2 = 0.66), physical (sprint 10 m: η p 2 = 0.26), and academic (mathematics: η p 2 = 0.19 and science: η p 2 = 0.15) performance parameters. The largest difference (p 0.5) correlation between parameters of different dimensions (e.g., anthropometric vs. physical performance parameters) was found. In conclusion, the highest BMI group exhibited similar physical and academic performances than the lowest group. Thus, these data emphasize the importance and appropriateness to engage young Qatari schoolchildren in physical activity as it associates with superior academic performance

Differences in fitness and academic attainment between obese, and non obese school-age adolescent handball players:an explorative, cross-sectional study

This study investigated differences in physical fitness and academic attainment in obese and non-obese adolescent handball players. A total of 31 males (age: 15.5 ± 1.2 years; body mass: 77.8 ± 17.7 kg; height: 1.71 ± 0.10 m; body mass index (BMI): 26.8 ± 6.9 kg/m2; body fat: 26.4 ± 6.34%) from the Qatar handball first division participated and were divided into two body fat percentage (%BF) groups (i.e., obese or non-obese). Anthropometrics (height, mass, BMI, and %BF) and physical performance testing ability (T-half test for change-of-direction (COD); squat jump (SJ), countermovement jump (CMJ), and 10 and 15 m sprints; medicine ball throw (MBT), and aerobic capacity (Yo-Yo Intermittent Recovery Test level 1 (Yo-Yo IR1)) were determined. Academic attainment was determined through grade point averages (GPA). Non-obese participants had superior performances in mathematics (p < 0.001) and science (p = 0.013), agility T-half test (p = 0.001), CMJ (p < 0.001), and 15 m sprint (p = 0.019). Correlations were found between T-half test and mathematics (r = 0.500) and science (r = 0.484). To conclude, obese school-age handball players have poorer fitness and academic performances than normal body weight adolescents

Validity of resting heart rate derived from contact-based smartphone photoplethysmography compared with electrocardiography:a scoping review and checklist for optimal acquisition and reporting

Background: With the rise of smartphone ownership and increasing evidence to support the suitability of smartphone usage in healthcare, the light source and smartphone camera could be utilized to perform photoplethysmography (PPG) for the assessment of vital signs, such as heart rate (HR). However, until rigorous validity assessment has been conducted, PPG will have limited use in clinical settings.Objective: We aimed to conduct a scoping review assessing the validity of resting heart rate (RHR) acquisition from PPG utilizing contact-based smartphone devices. Our four specific objectives of this scoping review were to (1) conduct a systematic search of the published literature concerning contact-based smartphone device-derived PPG, (2) map study characteristics and methodologies, (3) identify if methodological and technological advancements have been made, and (4) provide recommendations for the advancement of the investigative area.Methods: ScienceDirect, PubMed and SPORTDiscus were searched for relevant studies between January 1st, 2007, and November 6th, 2022. Filters were applied to ensure only literature written in English were included. Reference lists of included studies were manually searched for additional eligible studies.Results: In total 10 articles were included. Articles varied in terms of methodology including study characteristics, index measurement characteristics, criterion measurement characteristics, and experimental procedure. Additionally, there were variations in reporting details including primary outcome measure and measure of validity. However, all studies reached the same conclusion, with agreement ranging between good to very strong and correlations ranging from r = .98 to 1.Conclusions: Smartphone applications measuring RHR derived from contact-based smartphone PPG appear to agree with gold standard electrocardiography (ECG) in healthy subjects. However, agreement was established under highly controlled conditions. Future research could investigate their validity and consider effective approaches that transfer these methods from laboratory conditions into the “real-world”, in both healthy and clinical populations

Neutral and Cationic Rare Earth Metal Alkyl and Benzyl Compounds with the 1,4,6-Trimethyl-6-pyrrolidin-1-yl-1,4-diazepane Ligand and Their Performance in the Catalytic Hydroamination/Cyclization of Aminoalkenes

A new neutral tridentate 1,4,6-trimethyl-6-pyrrolidin-1-yl-1,4-diazepane (L) was prepared. Reacting L with trialkyls M(CH2SiMe3)3(THF)2 (M = Sc, Y) and tribenzyls M(CH2Ph)3(THF)3 (M = Sc, La) yielded trialkyl complexes (L)M(CH2SiMe3)3 (M = Sc, 1; M = Y, 2) and tribenzyl complexes (L)M(CH2Ph)3 (M = Sc, 3; M = La, 4). Complexes 1 and 2 can be converted to their corresponding ionic compounds [(L)M(CH2SiMe3)2(THF)][B(C6H5)4] (M = Sc, Y) by reaction with [PhNMe2H][B(C6H5)4] in THF. Complexes 3 and 4 can be converted to cationic species [(L)M(CH2Ph)2]+ by reaction with [PhNMe2H][B(C6F5)4] in C6D5Br in the absence of THF. The neutral complexes 1-4 and their cationic derivatives were studied as catalysts for the hydroamination/cyclization of 2,2-diphenylpent-4-en-1-amine and N-methylpent-4-en-1-amine reference substrates and compared with ligand-free Sc, Y, and La neutral and cationic catalysts. The most effective catalysts in the series were the cationic L-yttrium catalyst (for 2,2-diphenylpent-4-en-1-amine) and the cationic lanthanum systems (for N-methylpent-4-en-1-amine). For the La catalysts, evidence was obtained for release of L from the metal during catalysis.

Six weeks of conditioning exercise increases total, but not free testosterone in lifelong sedentary aging men

Introduction: Advancing age is associated with a gradual decline in circulating androgens, and the putative role of exercise training on systemic androgens remains to be adequately defined. Methods: The present investigation examined the impact of 6 weeks of supervised exercise training on resting levels of systemic hormones in a cohort of lifelong sedentary men [SED (n = 28), 62.5 ± 5.3 years], compared with a positive control group of age-matched lifelong exercisers [LE (n = 20), 60.4 ± 4.7 years, >30 years training history]. Blood hormones were sampled pre- and post-intervention from an antecubital forearm vein and analysed using electrochemiluminescent immunoassay. Cardiorespiratory fitness () was determined via indirect calorimetry during an incremental cycle test to volitional exhaustion. Results: Analysis of variance (ANOVA) revealed a lack of significant change in any parameter amongst LE, whilst SED experienced a significant exercise-induced improvement in cardiorespiratory fitness and total testosterone (all p  0.05) amongst SED. Conclusions: Although resting levels of systemic total testosterone increased in response to 6 weeks of exercise training, increases in SHBG negated any potential relationship between calculated-free or bioavailable testosterone. These findings indicate that increases in bioavailable testosterone fraction are not required for cardiorespiratory fitness improvements in aging men

Effect of coronavirus-19 restrictions in male handball players:physical activity, sedentary behavior, and satisfaction with life

This experiment examined physical activity (PA), sitting time, and satisfaction with life (SL) in European (45%) and Middle Eastern and North African (MENA; 55%) handball players (n = 418; age: 25.6 ± 6.8 years; body mass: 88.1 ± 11.7 kg; height: 1.83 ± 0.08 m) during the coronavirus (COVID)-19 pandemic. The International Physical Activity (IPAQ) and Satisfaction of Life (LS) Questionnaires were administered. All PA variables (vigorous, moderate, walking, total PA) were negatively influenced, but no interaction effects (IE; region x time) were observed. Sitting time increased from 2.5 to 4.9 h∙weekday−1 (ηp2 = 0.80) and walking time decreased from 66.8 to 33.5 min∙day−1 (ηp2 = 0.83). Based on effect sizes (d), pre- to during-confinement reductions were similar between regions (MENA: d = 3.29; Europe: d = 3.41; IE: ηp2 = 0.01). The largest regional difference was in moderate PA (MENA: d = 1.88; Europe: d = 2.99; IE: ηp2 = 0.09). SL in the total sample reduced from 30.6 ± 2.02 to 13.9 ± 2.20 arbitrary units (AU). SL reduction was similar in both regions (dMENA = 8.44; dEUROPE = 8.06; IE: ηp2 = 0.01). To conclude, PA decreased during COVID-19 confinement, sitting time increased, and SL decreased irrespective of geographical region. These preliminary findings highlight risk of SL and physical inactivity during COVID-19 restrictions in 2021

Failing boys and moral panics: perspectives on the underachievement debate

The paper re-examines the underachievement debate from the perspective of the ‘discourse of derision’ that surrounds much writing in this area. It considers the contradictions and inconsistencies which underpin much of the discourse – from a reinterpretation of examination scores, to the conflation of the concepts of ‘under’ and ‘low’ achievement and finally to the lack of consensus on a means of defining and measuring the term underachievement. In doing so, this paper suggests a more innovative approach for understanding, re-evaluating and perhaps rejecting the notion of underachievement

Fitness, fatness, and academic attainment in male schoolchildren from a soccer academy

This investigation explored the association between anthropometric measures, fitness, and academic attainment (mathematics and science grade point average [GPA]) in male schoolchildren from a soccer academy. Thirty-one males (age: 10.3 ± 1.19 years; body mass: 41.7 ± 6.5 kg; height: 1.43 ± 0.07 m; body mass index (BMI): 20.2 ± 2.8 kg/m(2)) participated. Body mass, body fat percentage (%BF), and BMI were used as measures of anthropometry. The Yo-Yo Intermittent Recovery Test (level 1), squat and counter-movement jumps (SJ and CMJ), static balance, 10 and 15 m sprint, and a T-half test for change-of-direction (CoD) performance were used to measure fitness parameters. The GPA of mathematics and science determined academic attainment. All physical performance tests showed excellent relative reliability. ICC was between 0.87 (10 m sprint) and 1.00 (15 m sprint, CMJ). Regarding correlations between fatness and academic attainment, we found three correlations of practical value (r > 0.5), but only for mathematics (BMI: r = 0.540, subscapular skinfold: r = 0.589, body fat: r = 0.560). Mathematics was relevantly correlated with 15 m sprint (r = 0.574) and Yo-Yo IR1 test (r = 0.770). Only static balance (r = 0.428) did not reach the relevance criteria (r > 0.5). Science only showed large correlations with static balance (r = 0.620) and Yo-Yo IR1 test (r = 0.730). In conclusion, fatness and fitness are related to academic attainment in schoolchildren. In addition, except for static balance, all physical performance parameters were relevantly (r > 0.5) correlated with mathematics