118 research outputs found

    A narrative review of limb dominance: task specificity and the importance of fitness testing

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    Preferential limb function must be sustained through repetitious asymmetrical activities for continuous athletic development and ultimately, optimal athletic performance. As such, the prevalence of limb dominance and between-limb differences are common in athletes. Severe between-limb differences have been associated with reductions in athletic performance and increased injury risk in athletes. However, in the current literature, the terms limb preference and limb dominance have been used inter-changeably. Together, these terms include a limb which is subjectively preferred and one that is objectively dominant in one or more performance measures from a variety of athletic tasks. In this review, we 1) discuss reported correspondence between task-specific limb preference and limb dominance outcomes in athletes, 2) provide greater context and distinction between the terms limb preference and limb dominance, and 3) to offer pragmatic strategies for practitioners to assess context-specific limb dominance. A limb which is subjectively preferred is not necessarily objectively dominant in one or more athletic qualities or sport-specific tasks. Further to this, a limb which is objectively superior in one task may not exhibit such superiority in a separate task. Thus, limb preference and limb dominance are both task-specific. As such, we propose that practitioners intentionally select tasks for limb dominance assessment which resemble the most relevant demands of sport. Because limb dominance profiles are inconsistent, we suggest that practitioners increase assessment frequency by integrating limb dominance testing into standard training activities. This will allow practitioners to better understand when changes reflect sport-specific adaptation versus potential performance or injury ramifications

    Sublogarithmic uniform Boolean proof nets

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    Using a proofs-as-programs correspondence, Terui was able to compare two models of parallel computation: Boolean circuits and proof nets for multiplicative linear logic. Mogbil et. al. gave a logspace translation allowing us to compare their computational power as uniform complexity classes. This paper presents a novel translation in AC0 and focuses on a simpler restricted notion of uniform Boolean proof nets. We can then encode constant-depth circuits and compare complexity classes below logspace, which were out of reach with the previous translations.Comment: In Proceedings DICE 2011, arXiv:1201.034

    Why sports should embrace bilateral asymmetry: a narrative review

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    (1) Background: Asymmetry is ubiquitous in nature and humans have well-established bilateral asymmetries in their structures and functions. However, there are (mostly unsubstantiated) claims that bilateral asymmetries may impair sports performance or increase injury risk. (2) Objective: To critically review the evidence of the occurrence and effects of asymmetry and sports performance. (3) Development: Asymmetry is prevalent across several sports regardless of age, gender, or competitive level, and can be verified even in apparently symmetric actions (e.g., running and rowing). Assessments of bilateral asymmetries are highly task-, metric-, individual-, and sport-specific; fluctuate significantly in time (in magnitude and, more importantly, in direction); and tend to be poorly correlated among themselves, as well as with general performance measures. Assessments of sports-specific performance is mostly lacking. Most studies assessing bilateral asymmetries do not actually assess the occurrence of injuries. While injuries tend to accentuate bilateral asymmetries, there is no evidence that pre-existing asymmetries increase injury risk. While training programs reduce certain bilateral asymmetries, there is no evidence that such reductions result in increased sport-specific performance or reduced injury risk. (4) Conclusions: Bilateral asymmetries are prevalent in sports, do not seem to impair performance, and there is no evidence that suggests that they increase injury risk

    Reverse engineering in strength and conditioning: applications to agility training

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    Typically, a coach may follow a process in which they first identify the key performance indicators of their sport, determine the physical attributes that map back to them, and then distribute the development of those capacities over the allocated timeframe. Furthermore, effective training plans are based on a theoretical or biological basis for how we move and adapt to exercise stimuli, coupled with an understanding of how these are best sequenced, such that one stimulus and subsequent adaptation can potentiate the next. Thus, reverse or backward engineering, when appropriately converged with the plans of those devised around nutrition, conditioning, technical, and tactical training for example likely gives athletes the best chance of attaining their performance goals. The aim of this paper is to describe the application of reverse engineering, exampling it within the context of developing an athlete who can demonstrate a high level of agility

    Risk Assessment of Male Infertility in People Aged 28 to 52, in the City of Parakou (Benin).

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    We evaluated male infertility in a moderately westernized population by macroscopic and microscopic examination. 29% of the population is free from difficulty conceiving; 34.90% has a relative difficulty to good mobility and 28.32% has a relative difficulty to the eligible number of sperm per ml. We found no correlation between the factors studied and the age of patients. Our work allows us to hypothesize the involvement of environmental causes among others knowing that in these environments the presence of heavy metals has been detected

    Knowledge-Attitudes-Practices About Malaria Among Communities in Southern Benin

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    Malaria still remains the main public health problem in Benin. We explored the determinants that influenced malaria treatment as well as protective behaviors, to generate a framework of useful ideas as alternative strategies against malaria. A cross-sectional survey of the knowledge, attitudes and practices (KAP) was conducted at Hozin, Vakon and Agblangandan districts in southern region of Benin. Descriptive statistics were computed and mixed logistic regression helped evaluating the relationship between frequency of each category of severity of malaria and sex group, educational level, treatment, means of self-protection against mosquitoes and identification of the cause of malaria. A significant proportion 750 (81.3%) (p<0.001) of participants stated that malaria was caused by mosquitoes. The respondents who mentioned sun as the cause of malaria, have trivialized more malaria in a proportion of about 59.30% (OR=2.67 [95% CI 1.61-4.44]) followed by those who have reported the cause of body weakness (43.68%) (OR=2.97 [95% CI 1.68-5.28]). Poor knowledge justifies the trivialization of the disease and poor management of malaria control means. National Malaria Control Programs should improve access to education, especially for women and could help improving prevention and control behaviours against malaria in communities

    Infographic. One small step for man, one giant leap for men's health: a meta-analysis of behaviour change interventions to increase men's physical activity.

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    OBJECTIVE:To determine the effects of behaviour change interventions on men's physical activity (postintervention), sustained change in physical activity behaviour (≥12 months postintervention) and to identify variations in effects due to potential moderating variables (eg, theoretical underpinning, gender-tailored, contact frequency). DESIGN:Systematic review with meta-analysis. Pooled effect size (Cohen's d) was calculated assuming a random-effects model. Homogeneity and subsequent exploratory moderator analyses were assessed using Q, T2 and I2. DATA SOURCES:Medline, EMBASE, CINAHL, SportDiscus and Web of Science to April 2019. ELIGIBILITY CRITERIA FOR SELECTED STUDIES:Randomised control trials of behaviour change interventions in men (≥18 years) where physical activity was an outcome and data were from men-only studies or disaggregated by sex. RESULTS:Twenty-six articles described 24 eligible studies. The overall mean intervention effect on men's physical activity was 0.35 (SE=0.05; 95% CI 0.26 to 0.45; p<0.001). This effect size is consistent with an increase of approximately 97 min of total physical activity per week or 980 steps per day. Intervention moderators associated with greater increases in physical activity included objective physical activity outcome measures, a gender-tailored design, use of a theoretical framework, shorter length programmes (≤12 weeks), using four or more types of behaviour change techniques and frequent contact with participants (≥1 contact per week). 12 studies included additional follow-up assessments (≥12 months postintervention) and the overall mean effect was 0.32 (SE=0.09; 95% CI 0.15 to 0.48; p<0.001) for that sustained increase in physical activity. SUMMARY:Behaviour change interventions targeting men's physical activity can be effective. Moderator analyses are preliminary and suggest research directions

    Sex differences in lipid and glucose kinetics after ingestion of an acute oral fructose load

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    The increase in VLDL TAG concentration after ingestion of a high-fructose diet is more pronounced in men than in pre-menopausal women. We hypothesised that this may be due to a lower fructose-induced stimulation of de novo lipogenesis (DNL) in pre-menopausal women. To evaluate this hypothesis, nine healthy male and nine healthy female subjects were studied after ingestion of oral loads of fructose enriched with 13C6 fructose. Incorporation of 13C into breath CO2, plasma glucose and plasma VLDL palmitate was monitored to evaluate total fructose oxidation, gluconeogenesis and hepatic DNL, respectively. Substrate oxidation was assessed by indirect calorimetry. After 13C fructose ingestion, 44·0 (sd 3·2)% of labelled carbons were recovered in plasma glucose in males v. 41·9 (sd 2·3)% in females (NS), and 42·9 (sd 3·7)% of labelled carbons were recovered in breath CO2 in males v. 43·0 (sd 4·5)% in females (NS), indicating similar gluconeogenesis from fructose and total fructose oxidation in males and females. The area under the curve for 13C VLDL palmitate tracer-to-tracee ratio was four times lower in females (P<0·05), indicating a lower DNL. Furthermore, lipid oxidation was significantly suppressed in males (by 16·4 (sd 5·2), P<0·05), but it was not suppressed in females (−1·3 (sd 4·7)%). These results support the hypothesis that females may be protected against fructose-induced hypertriglyceridaemia because of a lower stimulation of DNL and a lower suppression of lipid oxidatio

    Purification and Characterization of Trehalase From Acyrthosiphon pisum, a Target for Pest Control.

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    Insect trehalases are glycoside hydrolases essential for trehalose metabolism and stress resistance. We here report the extraction and purification of Acyrthosiphon pisum soluble trehalase (ApTreh-1), its biochemical and structural characterization, as well as the determination of its kinetic properties. The protein has been purified by ammonium sulphate precipitation, first followed by an anion-exchange and then by an affinity chromatography. The SDS-PAGE shows a main band at 70 kDa containing two isoforms of ApTreh-1 (X1 and X2), identified by mass spectrometry and slightly contrasting in the C-terminal region. A phylogenetic tree, a multiple sequence alignment, as well as a modelled 3D-structure were constructed and they all reveal the ApTreh-1 similarity to other insect trehalases, i.e. the two signature motifs (179)PGGRFRELYYWDTY(192) and (479)QWDFPNAWPP(489), a glycine-rich region (549)GGGGEY(554), and the catalytic residues Asp336 and Glu538. The optimum enzyme activity occurs at 45 °C and pH 5.0, with K(m) and V(max) values of ~ 71 mM and ~ 126 µmol/min/mg, respectively. The present structural and functional characterization of soluble A. pisum trehalase enters the development of new strategies to control the aphids pest without significant risk for non-target organisms and human health
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