61 research outputs found
On metal-deficient barium stars and their link with yellow symbiotic stars
This paper addresses the question of why metal-deficient barium stars are not
yellow symbiotic stars (YSyS). Samples of (suspected) metal-deficient barium
(mdBa) stars and YSyS have been collected from the literature, and their
properties reviewed. It appears in particular that the barium nature of the
suspected mdBa stars needs to be ascertained by detailed abundance analyses.
Abundances are therefore derived for two of them, HD 139409 and HD 148897,
which reveal that HD 148897 should not be considered a barium star. HD 139409
is a mild barium star, with overabundances observed only for elements belonging
to the first s-process peak (Y and Zr). The evidence for binarity among mdBa
stars is then reviewed, using three different methods: (i) radial-velocity
variations (from CORAVEL observations), (ii) Hipparcos astrometric data, and
(iii) a method based on the comparison between the Hipparcos and Tycho-2 proper
motions. A first-time orbit is obtained for HIP 55852, whereas evidence for the
(so far unknown) binary nature of HIP 34795, HIP 76605, HIP 97874 and HIP
107478 is presented. Two stars with no evidence for binarity whatsoever (HIP
58596 and BD +3 2688) are candidates low-metallicity thermally-pulsing
asymptotic giant branch stars, as inferred from their large luminosities. The
reason why mdBa stars are not YSyS is suggested to lie in their different
orbital period distributions: mdBa stars have on average longer orbital periods
than YSyS, and hence their companion accretes matter at a lower rate, for a
given mass loss rate of the giant star. The definite validation of this
explanation should nevertheless await the determination of the orbital periods
for the many mdBa stars still lacking periods, in order to make the comparison
more significant.Comment: Astronomy & Astrophysics, in press; 16 pages, 14 figures; also
available at http://www.astro.ulb.ac.be/Html/ps.html#PR
Highly selective BSA imprinted polyacrylamide hydrogels facilitated by a metal-coding MIP approach
We report the fabrication of metal-coded molecularly imprinted polymers (MIPs) using hydrogel-based protein imprinting techniques. A Co(II) complex was prepared using (E)-2-((2 hydrazide-(4-vinylbenzyl) hydrazono)methyl)phenol; along with iron(III) chloroprotoporphyrin (Hemin), vinylferrocene (VFc), zinc (II) protoporphyrin (ZnPP) and protoporphyrin (PP), these complexes were introduced into the MIPs as co-monomers for metal-coding of non-metalloprotein imprints. Results indicate a 66% enhancement for bovine serum albumin (BSA) protein binding capacities (Q, mg/g) via metal-ion/ligand exchange properties within the metal-coded MIPs. Specifically, Co(II)-complex-based MIPs exhibited 92 ± 1% specific binding with Q values of 5.7 ± 0.45 mg BSA/g polymer and imprinting factors (IF) of 14.8 ± 1.9 (MIP/non-imprinted (NIP) control). The selectivity of our Co(II)-coded BSA MIPs were also tested using bovine haemoglobin (BHb), lysozyme (Lyz), and trypsin (Tryp). By evaluating imprinting factors (K), each of the latter proteins was found to have lower affinities in comparison to cognate BSA template. The hydrogels were further characterised by thermal analysis and differential scanning calorimetry (DSC) to assess optimum polymer composition
National Rugby League athletes and tendon tap reflex assessment: a matched cohort clinical study
Eutrophication, acidification and abundance of Baltic herring larvae in the Vaasa archipelago, Gulf of Bothnia in 1983â1991
Surface water nitrogen and phosphorus concentration, pH and chlorophyll-a content were monitored at 28 stations in the Vaasa archipelago (63°05ÂŽN, 21°30ÂŽE) in JuneâAugust 1983â1991, and pH additionally during the spring runoff maximum. Herring larvae were sampled weekly or biweekly in MayâAugust during the period. High levels of nutrients and chlorophyll-a were found in the innermost archipelago receiving non-point runoff load and municipal sewage load. Elevated nutrient and chlorophyll-a levels extend to the outer border of the archipelago. River water entering the area is acidified by acid sulphate soils, and pH values of 5 or lower were measured in spring each year in runoff and in the innermost bays. The areas affected by acid runoff have low levels of phosphorous and chlorophyll-a. Herring larvae densities were highest in the outer part of the study area, and there was a negative correlation between larval density and the chlorophyll-a content. It was concluded that the entire study area is to some extent eutrophicated by runoff and sewage nutrient load. Recurring acidity limits phytoplankton production in the innermost bays. Acidity or excessive eutrophication may preclude the utilization of the innermost bays for feeding by herring larvae
Changes in strength and power performance and serum hormone concentrations during 12 weeks of taskâspecific or strength training in conscripts
The purpose of this study was to investigate the effects of two different training programs on strength and power performance and serum hormone concentrations. A total of 104 male soldiers volunteered and took part in the 12âweek training period with baseline, midâ, and postâmeasurements of body composition, muscle strength, lower and upper body power, and blood samples to determine serum hormone concentrations. The mean (±SD) age of subjects was 20 ± 1 years, height 180 ± 6 cm and body mass 72.4 ± 8.8 kg. The subjects were divided into three different training groups: soldier taskâspecific training (TS), strength training (ST), and control (CON). Each group had a total of 18 training sessions during the 12âweek study. In the muscle strength tests, most improvements could be observed in the TS and ST groups, especially, during the first weeks of the training period. Maximal isometric leg extension force increased significantly by 7.9 ± 12.2% (p < .05) in the TS and 7.1 ± 12.6% (p < .05) in the ST groups between the PRE and MID, as well as between the PRE and POST measurements by 8.1 ± 12.4% (p < .05) in TS and 12.3 ± 15.3% (p < .01) in ST. Serum TES concentration increased significantly in TS between the PRE and MID (16.8 ± 33.9%) and PRE and POST (11.2 ± 16.7%) measurements. Serum COR concentrations decreased in TS between the MID and POST (â7.8 ± 10.9%) and PRE and POST (â11.0 ± 14.3%) measurements. Although the differences observed were rather minor in magnitude, training in the TS and ST groups led to greater improvements in muscle strength and power performance compared to the training in the CON group. The development of strength and/or power of the lower and upper body was greater in the TS and ST groups, which is crucial for warfighter's performance. Therefore, it is important to have a structured resistanceâtraining program during military training to optimize the strength, power, and militaryâspecific performance.peerReviewe
Changes in physical fitness and anthropometrics differ between female and male recruits during the Finnish military service
Introduction: Military training programmes are often similar for male and female recruits despite sex differences in physical performance that may influence training adaptations during military service. The present study aimed to compare changes in physical fitness and anthropometrics between Finnish female and male recruits during military service.
Methods: A total of 234â690 male and 3549 female recruits participated in fitness tests at the beginning and end of military service between 2005 and 2015. Anthropometric measurements were body mass, height, body mass index (BMI) and waist circumference (WC). Fitness tests consisted 12âmin running, standing long jump, and sit-ups and push-ups.
Results: No changes were observed in anthropometrics, while both sexes improved most of the fitness test results. After adjustment for service time, branch, age, initial fitness test results, BMI and WC, improvement in running test performance was 158âm (95%âCI 142 to 173, pâ€0.001) greater in male than female recruits. Similarly, improvements were larger in male recruits for push-ups (5 reps/min, 95%âCI 5 to 6, pâ€0.001), sit-ups (2 reps/min, 95%âCI 2 to 3, pâ€0.001) and standing long jump (12âcm, 95%âCI 11 to 13, pâ€0.001) when compared with women.
Conclusions: The study revealed sex differences in adaptations to the standardised military training. Both male and female recruits improved their physical fitness, but smaller gains were observed in women using the same training programme. The mechanisms explaining sex differences in adaptations to military training, and whether tailored training programmes are needed specifically for female recruits to reduce sex differences during military service, warrants further studies.peerReviewe
Physical fitness and anthropometrics in Finnish soldiers during their early career : prospective changes during a 3-year follow-up
Introduction: Physical fitness is a fundamental capability required of military personnel, but studies focusing on longitudinal changes in physical fitness and anthropometrics in soldiers are lacking. The aim was to evaluate physical fitness and anthropometrics in soldiers during their early career.
Methods: A 3-year prospective study included 180 male soldiers (baseline age 26±2âyears) with measures of a 12âmin running test, standing long jump, sit-up and push-up tests, and body mass, height and waist circumference (WC). Baseline data were stratified into tertiles, and the changes within each tertile were analysed using dependent t-tests and analysis of variance.
Results: 12âmin running test distance decreased on average by 2% (â54 m), sit-up performance 3% (â1.5 repetitions (reps)/min), push-up performance 4% (â1.9 reps/min) and standing long jump performance 1% (â2.1 cm) over the 3-year period (p<0.05). Both aerobic and muscular fitness decreased consistently among the highest baseline tertile (12âmin running test: â70âm, sit-ups: â3.2 reps/min, push-ups: â7.5 reps/min, standing long jump: â5.5âcm; p<0.001), whereas both aerobic and muscular fitness levels were maintained and push-up performance was improved (p<0.05) in the lowest baseline tertiles. Body mass increased on average by 4% (+3.4 kg) and WC by 4% (+3.9 cm) (p<0.001), and these increases were observed for all baseline tertiles (p<0.05).
Conclusions: Small decrements in physical fitness and anthropometrics exist during the early career of soldiers. The changes in physical fitness differed according to baseline fitness levels. The results indicate that support for exercise training may be needed even in a soldierâs early career.peerReviewe
- âŠ