The relationship between motor competence and health-related fitness in children and adolescents

Background and aims : In the last twenty years, there has been increasing evidence that Motor Competence (MC) is vital for developing an active and healthy lifestyle. This study analyses the associations between motor competence and its components, with health-related fitness (HRF). Methods : A random sample of 546 children (278 males, mean = 10.77 years) divided into four age groups (7-8; 9-10; 11-12; 13-14 years old) was evaluated. A quantitative MC instrument (evaluating stability, locomotor and manipulative skills), a maximal multistage 20-m shuttle-run test and the handgrip test, height and BMI were used in the analyses. Pearson correlations and standard regression modelling were performed to explore the associations between variables. Results : Moderate to strong significant correlations (0.49 < r < 0.73) were found between MC and HRF, for both sexes, and correlation values were stable across the age groups. The MC model explained 74% of the HRF variance, with the locomotor component being the highest predictor for the entire sample (beta =.302; p < .001). Gender-related differences were found when boys and girls were analysed at each age group. Locomotor MC for girls was the most consistent significant predictor of HRF across all age groups (0.47 < beta < 0.65; all p <=.001). For boys, significant predictors were locomotor and manipulative MC (0.21 <beta< 0.49; all p < .05) in the two younger age groups (7-8 and 9-10 years) and stability (0.50 <beta< 0.54; all p <=.001) for the older two age groups (11-12 and 13-14 years). Conclusion : These results support the idea that: (1) the relationship between overall MC and HRF is strong and stable across childhood and early adolescence; (2) when accounting for the different MC components, boys and girls show different relationship patterns with HFR across age

The relationship between motor competence and health-related fitness in children and adolescents

Background and aims In the last twenty years, there has been increasing evidence that Motor Competence (MC) is vital for developing an active and healthy lifestyle. This study analyses the associations between motor competence and its components, with health-related fitness (HRF). Methods A random sample of 546 children (278 males, mean = 10.77 years) divided into four age groups (7?8; 9?10; 11?12; 13?14 years old) was evaluated. A quantitative MC instrument (evaluating stability, locomotor and manipulative skills), a maximal multistage 20-m shuttle-run test and the handgrip test, height and BMI were used in the analyses. Pearson correlations and standard regression modelling were performed to explore the associations between variables. Results Moderate to strong significant correlations (0.49 < r < 0.73) were found between MC and HRF, for both sexes, and correlation values were stable across the age groups. The MC model explained 74% of the HRF variance, with the locomotor component being the highest predictor for the entire sample (? = .302; p < .001). Gender-related differences were found when boys and girls were analysed at each age group. Locomotor MC for girls was the most consistent significant predictor of HRF across all age groups (0.47 < ? < 0.65; all p .001). For boys, significant predictors were locomotor and manipulative MC (0.21 < ? < 0.49; all p < .05) in the two younger age groups (7?8 and 9?10 years) and stability (0.50 < ? < 0.54; all p .001) for the older two age groups (11?12 and 13?14 years). Conclusion These results support the idea that: (1) the relationship between overall MC and HRF is strong and stable across childhood and early adolescence; (2) when accounting for the different MC components, boys and girls show different relationship patterns with HFR across age.4811-99FE-2ECD | Luis Paulo Rodriguesinfo:eu-repo/semantics/publishedVersio

Representation of Markov chains by random maps: existence and regularity conditions

We systematically investigate the problem of representing Markov chains by families of random maps, and which regularity of these maps can be achieved depending on the properties of the probability measures. Our key idea is to use techniques from optimal transport to select optimal such maps. Optimal transport theory also tells us how convexity properties of the supports of the measures translate into regularity properties of the maps via Legendre transforms. Thus, from this scheme, we cannot only deduce the representation by measurable random maps, but we can also obtain conditions for the representation by continuous random maps. Finally, we present conditions for the representation of Markov chain by random diffeomorphisms.Comment: 22 pages, several changes from the previous version including extended discussion of many detail

Revisiting special relativity: A natural algebraic alternative to Minkowski spacetime

Minkowski famously introduced the concept of a space-time continuum in 1908, merging the three dimensions of space with an imaginary time dimension $i c t$, with the unit imaginary producing the correct spacetime distance $x^2 - c^2 t^2$, and the results of Einstein's then recently developed theory of special relativity, thus providing an explanation for Einstein's theory in terms of the structure of space and time. As an alternative to a planar Minkowski space-time of two space dimensions and one time dimension, we replace the unit imaginary $i = \sqrt{-1}$, with the Clifford bivector $\iota = e_1 e_2$ for the plane that also squares to minus one, but which can be included without the addition of an extra dimension, as it is an integral part of the real Cartesian plane with the orthonormal basis $e_1$ and $e_2$. We find that with this model of planar spacetime, using a two-dimensional Clifford multivector, the spacetime metric and the Lorentz transformations follow immediately as properties of the algebra. This also leads to momentum and energy being represented as components of a multivector and we give a new efficient derivation of Compton's scattering formula, and a simple formulation of Dirac's and Maxwell's equations. Based on the mathematical structure of the multivector, we produce a semi-classical model of massive particles, which can then be viewed as the origin of the Minkowski spacetime structure and thus a deeper explanation for relativistic effects. We also find a new perspective on the nature of time, which is now given a precise mathematical definition as the bivector of the plane.Comment: 29 pages, 2 figure

Compartmentalized cytotoxic immune response leads to distinct pathogenic roles of natural killer and senescent CD8⁺ T cells in human cutaneous leishmaniasis

Cytotoxic activity mediated by CD8+ T cells is the main signature of the immunopathogenesis of cutaneous leishmaniasis (CL). Here, we performed a broad evaluation of natural killer (NK) cell phenotypic and functional features during cutaneous leishmaniasis. We demonstrate for the first time that CL patients present the accumulation of circulating NK cells with multiple features of replicative senescence including low proliferative capacity and shorter telomeres, elevated expression of CD57, KLRG1 but diminished CD27 stimulatory receptor expression. Moreover, they exhibited higher cytotoxic and inflammatory potential than age‐matched controls. The accumulation of circulating senescent NK cells (CD56dim CD57bright) correlated positively with skin lesion size in the same patients, suggesting that they, like circulating senescent CD8+ T cells, may contribute to the immunopathology of CL. However, this senescent population had lower cutaneous lymphocyte antigen expression and so had diminished skin‐homing potential compared with total or senescent CD8+ T cells. This was confirmed in CL skin lesions where we found a predominance of CD8+ T cells (both senescent and non‐senescent) that correlated with the severity of the disease. Although there was also a correlation between the proportions of senescent NK cells (CD56+ CD57+) in the skin and lesion size, this was less evident. Collectively our results demonstrate first‐hand that senescent cytotoxic cells may mediate skin pathology during human cutaneous leishmaniasis. However, as senescent cytotoxic CD8+ T cells predominate in the skin lesions, they may have a greater role than NK cells in mediating the non‐specific skin damage in CL

Correction to: Through the looking glass: a systematic review of longitudinal evidence, providing new insight for motor competence and health

Tables 6, 7, 11 and 12 each include a header cell, near the top, stating the wording “Proportion of sig. analyses (without studies with > 4 comparisons)”. Table 6 also features a header cell at the bottom, stating “Proportion of sig total Locomotor/ Coordination /Stability analyses without studies with > 4 comparisons”.info:eu-repo/semantics/publishedVersio

A systematic review of longitudinal and experimental evidence providing new insight for motor competence and health

In 2008, a conceptual model explaining the role of motor competence (MC) on children’s physical activity (PA), health-related fitness, weight status and perceived MC was published by Stodden et al. The purpose of this review is to systematically compile mediation, longitudinal and experimental evidence in support of this model. Searches were undertaken for each pathway of interest using six relevant databases. Potential articles were identified though abstract and title checking (N = 585), then screened (n = 152), with 43 articles identified for extraction. Studies needed to: be original, peer-reviewed, include typically developing children and adolescents first assessed between 2 and 18 years and objective assessment of gross MC and at least one other model variable. Strength of evidence was calculated for each pathway in both directions by dividing the proportion of studies indicating a significantly positive pathway in the hypothesized direction by the total amount of studies investigating that pathway. Classifications were no association (0–33 %), indeterminate/inconsistent (34–59 %), or a positive “+” or negative “-” association (≥60 %). The latter category was classified as strong evidence (i.e., ++ or –) when four or more studies found an association. If the total number of studies in a domain of interest were three or less, this was considered insufficient evidence. There was strong evidence in both directions for a negative association between MC and weight status. There was indeterminate evidence between MC and fitness and indeterminate evidence from MC to PA and no evidence for the reverse. There was insufficient evidence for the MC to perceived MC pathway. There was strong positive evidence for the fitness-mediated pathway in both directions. There was indeterminate evidence for the perceived MC-mediated pathway from PA to MC and no evidence for the reverse. To test the whole model, the field needs robust longitudinal studies with multiple time points, including all variables in the model and accounting for confounding factors.N.C.V is supported by the Coordination for the Improvement of Higher Education Personel – CAPESPrint Brazil. V.P.L is supported by national funding through the Portuguese Foundation for Science and Technology, I.P., under project UID04045/2020 L.P.R is partially supported by the Portuguese Foundation for Science and Technology, I.P. under Project UID/DTP/04045/2019.info:eu-repo/semantics/publishedVersio

Incidence and diversity of the fungal genera Aspergillus and Penicillium in Portuguese almonds and chestnuts

Almonds (Prunus dulcis (Miller) D.A. Webb) and European (sweet) chestnuts (Castanea sativa Miller) are of great economic and social impact in Mediterranean countries, and in some areas they constitute the main income of rural populations. Despite all efforts to control fungal contamination, toxigenic fungi are ubiquitous in nature and occur regularly in worldwide food supplies, and these nuts are no exception. This work aimed to provide knowledge on the general mycobiota of Portuguese almonds and chestnuts, and its evolution from field to the end of storage. For this matter, 45 field chestnut samples and 36 almond samples (30 field samples and six storage samples) were collected in Trás-os-Montes, Portugal. All fungi belonging to genus Aspergillus were isolated and identified to the section level. Fungi representative of other genera were identified to the genus level. In the field, chestnuts were mainly contaminated with the genera Fusarium, Cladosporium, Alternaria and Penicillium, and the genus Aspergillus was only rarely found, whereas almonds were more contaminated with Aspergillus. In almonds, Aspergillus incidence increased significantly from field to the end of storage, but diversity decreased, with potentially toxigenic isolates belonging to sections Flavi and Nigri becoming more significant and widespread throughout storage. These fungi were determined to be moderately associated, which can be indicative of mycotoxin co-contamination problems if adequate storage conditions are not secured.P. Rodrigues was supported by grants SFRH/BD/28332/2006 from Fundacao para a Ciencia e a Tecnologia (FCT), and SFRH/PROTEC/49555/2009 from FCT and Polytechnic Institute of Braganca, Portugal

Genotoxicity biomonitoring of sewage in two municipal wastewater treatment plants using the Tradescantia pallida var. purpurea bioassay

The genotoxicity of untreated and treated sewage from two municipal wastewater treatment plants (WTP BN and WTP SJN) in the municipality of Porto Alegre, in the southern Brazilian state of Rio Grande do Sul, was evaluated over a one-year period using the Tradescantia pallida var. purpurea (Trad-MCN) bioassay. Inflorescences of T. pallida var. purpurea were exposed to sewage samples in February (summer), April (autumn), July (winter) and October (spring) 2009, and the micronuclei (MCN) frequencies were estimated in each period. The high genotoxicity of untreated sewage from WTP BN in February and April was not observed in treated sewage, indicating the efficiency of treatment at this WTP. However, untreated and treated sewage samples from WTP SJN had high MCN frequencies, except in October, when rainfall may have been responsible for reducing these frequencies at both WTPs. Physicochemical analyses of sewage from both WTPs indicated elevated concentrations of organic matter that were higher at WTP SJN than at WTP BN. Chromium was detected in untreated and treated sewage from WTP SJN, but not in treated sewage from WTP BN. Lead was found in all untreated sewage samples from WTP SJN, but only in the summer and autumn at WTP BN. These results indicate that the short-term Trad-MCN genotoxicity assay may be useful for regular monitoring of municipal WTPs