208 research outputs found
Emotion regulation choice: selecting between cognitive regulation strategies to control emotion
Physical and physiological attributes of soccer goalkeepers - Should we rely only on means and standard deviations?
The purpose of this study was twofold: (a) to profile physical characteristics and physiological attributes of soccer goalkeepers (GKs) who were divided into three age groups ā under 16 years, 16-19, and over 19, and (b) to examine the intra-individual variability among the GKs in each age group on all physical and physiological measurements performed in the study. The GKs underwent a series of physical (e.g., height, body mass, and percentage of body fat) and physiological (e.g., anaerobic profile, power and strength, and flexibility) tests. The three main findings of the current study were: (a) differences in physical characteristics and physiological attributes existed between GKs in the three age groups, (b) intra-individual variability can be found in most physical characteristics and physiological attributes of the GKs, and (c) the intra-individual variability was observed in all three groups. These findings emphasize the need for coaches to examine the intra-individual variability in GKs on their teams. These findings can be used by coaches when planning specific training programs for GKs of different age and skill levels
Simulation Fidelity and Skill Learning during Helicopter Egress Training: The Role of Vision
This project aimed to evaluate the effects of ambient lighting during practice and performance of simulated helicopter escape sequences. Participants were randomized to one of the following groups to practice a standard helicopter underwater escape sequence: Light (with room lights on), Dark (with room lights off), or Graduated (in the light for the first half and then in the dark for the second half of the trials). Following practice, participants had a minimum of 30Ā min break, followed by retention testing in the dark and then in the light. Dependent measures included accuracy and movement time. Results indicated that participants performed more accurately during the dark retention trial than during the light retention trial. This could be due to increased arousal elicited by performance in the dark or, alternatively, may suggest that performance of helicopter escape sequences is not visually mediated. Based on findings, it appears that training in the light is suitable for potential performance in the dark
Utjecaj uputa za fokus pažnje na ekonomiÄnost trÄanja pri submaksimalnim brzinama
The purpose of this study was to examine the effectiveness of external and internal focus of attention instructions on running economy at a submaximal velocity. Twenty-four male physical education students
ran on a treadmill at a velocity of 9.6 kmĀ·hr-1 in two 10-minute counterbalanced conditions: external focus (watching a video of running from the runnerās perspective), and internal focus (focusing on the movement of their legs). The external focus of attention provided visual feedback of the running velocity to the participants and was shown during the internal focus condition as well. No differences in physiological responses, running economy, or rating of perceived exertion were found between the two conditions. Based on the data of the current study, it was concluded that attentional focus does not affect running economy or physiological responses when running at submaximal velocities.Cilj je ovog istraživanja bio ispitati koliko instrukcije za (vanjski i unutarnji) fokus pažnje utjeÄu na ekonomiÄnost trÄanja pri submaksimalnim brzinama. Dvadeset i Äetiri studenta (muÅ”karca) kineziologije trÄala su po deset minuta na pokretnoj traci pri brzini od 9,6 km/h provodeÄi dva razliÄita eksperimentalna protokola usmjeravanja pažnje: vanjski fokus (gledanje videa snimljenoga iz perspektive trkaÄa) i unutarnji fokus (pažnja na kretnje vlastitih nogu).
Vanjski fokus pažnje omoguÄio je ispitanicima vizualnu povratnu informaciju o brzini trÄanja, a video snimka je prikazana i u uvjetima unutarnjeg fokusa pažnje. Nisu zabilježene znaÄajne razlike u fizioloÅ”kim odgovorima, ekonomiÄnosti trÄanja ili subjektivnoj procjeni optereÄenja izmeÄu dva eksperimentalna protokola. Na temelju podataka istraživanja zakljuÄeno je da fokus pažnje ne utjeÄe na ekonomiÄnost trÄanja ni fizioloÅ”ke reakcije prilikom trÄanja submaksimalnim brzinama
Extended-spectrum Ī²-lactamase-producing enterobacteriaceae shedding in farm horses versus hospitalized horses: Prevalence and risk factors
We aimed to investigate the prevalence, molecular characteristics and risk factors of extended-spectrum Ī²-lactamase (ESBL)-producing Enterobacteriaceae (ESBL-E) shedding in horses. A prospective study included three cohorts: (i) farm horses (13 farms, n = 192); (ii) on hospital admission (n = 168) and; (iii) horses hospitalized for ā„72 h re-sampled from cohort (ii) (n = 86). Enriched rectal swabs were plated, ESBL-production was confirmed (Clinical and Laboratory Standards Institute (CLSI)) and genes were identified (polymerase chain reaction (PCR)). Identification and antibiotic susceptibility were determined (Vitek-2). Medical records and ownersā questionnaires were analyzed. Shedding rates increased from 19.6% (n = 33/168) on admission to 77.9% (n = 67/86) during hospitalization (p < 0.0001, odds ratio (OR) = 12.12). Shedding rate in farms was 20.8% (n = 40/192), significantly lower compared to hospitalized horses (p < 0.0001). The main ESBL-E species (n = 192 isolates) were E. coli (59.9%, 115/192), Enterobacter sp. (17.7%, 34/192) and Klebsiella pneumoniae (13.0%, 25/192). The main gene group was CTX-M-1 (56.8%). A significant increase in resistance rates to chloramphenicol, enrofloxacin, gentamicin, nitrofurantoin, and trimethoprim-sulpha was identified during hospitalization. Risk factors for shedding in farms included breed (Arabian, OR = 3.9), sex (stallion, OR = 3.4), and antibiotic treatment (OR = 9.8). Older age was identified as a protective factor (OR = 0.88). We demonstrated an ESBL-E reservoir in equine cohorts, with a significant ESBL-E acquisition, which increases the necessity to implement active surveillance and antibiotic stewardship programs
Physiological characterization of the wild almond Prunus arabica stem photosynthetic capability
Leaves are the major plant tissue for transpiration and carbon fixation in deciduous trees. In harsh habitats, atmospheric CO2 assimilation via stem photosynthesis is common, providing extra carbon gain to cope with the detrimental conditions. We studied two almond species, the commercial Prunus dulcis cultivar āUm-el-Fahemā and the rare wild Prunus arabica. Our study revealed two distinctive strategies for carbon gain in these almond species. While, in P. dulcis, leaves possess the major photosynthetic surface area, in P. arabica, green stems perform this function, in particular during the winter after leaf drop. These two species' anatomical and physiological comparisons show that P. arabica carries unique features that support stem gas exchange and high-gross photosynthetic rates via stem photosynthetic capabilities (SPC). On the other hand, P. dulcis stems contribute low gross photosynthesis levels, as they are designed solely for reassimilation of CO2 from respiration, which is termed stem recycling photosynthesis (SRP). Results show that (a) P. arabica stems are covered with a high density of sunken stomata, in contrast to the stomata on P. dulcis stems, which disappear under a thick peridermal (bark) layer by their second year of development. (b) P. arabica stems contain significantly higher levels of chlorophyll compartmentalized to a mesophyll-like, chloroplast-rich, parenchyma layer, in contrast to rounded-shape cells of P. dulcis's stem parenchyma. (c) Pulse amplitude-modulated (PAM) fluorometry of P. arabica and P. dulcis stems revealed differences in the chlorophyll fluorescence and quenching parameters between the two species. (d) Gas exchange analysis showed that guard cells of P. arabica stems tightly regulate water loss under elevated temperatures while maintaining constant and high assimilation rates throughout the stem. Our data show that P. arabica uses a distinctive strategy for tree carbon gain via stem photosynthetic capability, which is regulated efficiently under harsh environmental conditions, such as elevated temperatures. These findings are highly important and can be used to develop new almond cultivars with agriculturally essential traits
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