Relación entre la capacidad de aceleración, cambio de dirección y salto horizontal en atletas jóvenes

The aim of this study was to analyze the relationship among the straight acceleration capacity, the change of direction ability (CODA) and the horizontal jumping (HJ) performance in young athletes. This study involved a total of 264 young athletes aged between 8 and 16 years (10.2 ± 2.6 years; 37.5 ± 11.7 kg, 1.4 ± 0.1 m, 17.7 ± 2.4 kg·m-2). The 5 and 15 m straight acceleration capacity, the CODA in the 505 test (505) and modified agility test (MAT), the horizontal counter movement jump (HCMJ) and the horizontal arm swing counter movement jump (HCMJAS) were assessed. The relationship between acceleration capacity in 5 m and CODA (505: r = 0.54, p <0.01 and MAT: r = 0.62, p <0.01) or acceleration capacity in 5 m and horizontal jump (HCMJ: r = -0 64, p <0.01 HCMJAS: r = -0.67, p> 0.05) were more consistent than the association among 15 m test and CODA or HJ. The association between MAT test and HJ (HCMJ: r = -0.73, p <0.01; HCMJAS: r = -0.74, p <0.01) was higher than the relationship between 505 test and HCMJ (r = -0.63, p <0.01) or 505 test and HCMJAS (r = -0.61, p <0.01). The type, the duration and the nature of these field tests determine the associations among different motor skills.El objetivo de este estudio fue analizar la asociación existente entre la capacidad de aceleración en línea recta, la capacidad de cambiar de dirección (CODA) y la capacidad de salto horizontal (SH) en jóvenes atletas. En este estudio participaron un total de 264 jóvenes atletas de entre 8 y 16 años (10,2 ± 2,6 años; 37,5 ± 11,7 kg; 1,4 ± 0,1 m, 17,7 ± 2,4 kg·m-2). Se evaluó la capacidad de aceleración en línea recta en los test de 5 y 15 m, la CODA en el test 505 (505) y en el modified agility test (MAT) y la capacidad de SH con contra movimiento (HCMJ) y manos libres (HCMJAS). La asociación entre la capacidad de aceleración en 5 m y los test de CODA (505: r = 0,54, p < 0,01 y MAT: r = 0,62, p < 0,01) o salto horizontal (HCMJ: r = -0,64, p < 0,01 y HCMJAS: r = -0,67, p > 0,05) fue más consistente que la asociación entre la aceleración en 15 m y los test de CODA o SH. La asociación entre el test MAT y el SH (HCMJ: r = -0,73, p < 0,01 y HCMJAS: r = -0,74, p < 0,01) fue mayor que la relación observada entre el 505 y el HCMJ (r = -0,63, p < 0,01) o el HCMJAS (r = -0,61, p < 0,01). El tipo, la duración y la naturaleza de los test de campo utilizados, condicionan las asociaciones observadas entre las distintas habilidades motoras

Experimental observation of nonlinear Thomson scattering

A century ago, J. J. Thomson showed that the scattering of low-intensity light by electrons was a linear process (i.e., the scattered light frequency was identical to that of the incident light) and that light's magnetic field played no role. Today, with the recent invention of ultra-high-peak-power lasers it is now possible to create a sufficient photon density to study Thomson scattering in the relativistic regime. With increasing light intensity, electrons quiver during the scattering process with increasing velocity, approaching the speed of light when the laser intensity approaches 10^18 W/cm^2. In this limit, the effect of light's magnetic field on electron motion should become comparable to that of its electric field, and the electron mass should increase because of the relativistic correction. Consequently, electrons in such high fields are predicted to quiver nonlinearly, moving in figure-eight patterns, rather than in straight lines, and thus to radiate photons at harmonics of the frequency of the incident laser light, with each harmonic having its own unique angular distribution. In this letter, we report the first ever direct experimental confirmation of these predictions, a topic that has previously been referred to as nonlinear Thomson scattering. Extension of these results to coherent relativistic harmonic generation may eventually lead to novel table-top x-ray sources.Comment: including 4 figure

No additional value of conventional and high-sensitivity cardiac troponin over clinical scoring systems in the differential diagnosis of type 1 versus type 2 myocardial infarction.

BACKGROUND: The distinction of type 1 and type 2 myocardial infarction (MI) is of major clinical importance. Our aim was to evaluate the diagnostic ability of absolute and relative conventional cardiac troponin I (cTnI) and high-sensitivity cardiac troponin T (hs-cTnT) in the distinction between type 1 and type 2 MI in patients presenting at the emergency department with non-ST-segment elevation acute chest pain within the first 12 h. METHODS: We measured cTnI (Dimension Vista) and hs-cTnT (Cobas e601) concentrations at presentation and after 4 h in 200 patients presenting with suspected acute MI. The final diagnosis, based on standard criteria, was adjudicated by two independent cardiologists. RESULTS: One hundred and twenty-five patients (62.5%)were classified as type 1 MI and 75 (37.5%) were type 2 MI. In a multivariable setting, age (relative risk [RR]=1.43, p=0.040), male gender (RR=2.22, p=0.040), T-wave inversion (RR=8.51, p<0.001), ST-segment depression (RR=8.71, p<0.001) and absolute delta hs-cTnT (RR=2.10, p=0.022) were independently associated with type 1 MI. In a receiver operating characteristic curve analysis, the discriminatory power of absolute delta cTnI and hs-cTnT was significantly higher compared to relative c-TnI and hs-cTnT changes. The additive information provided by cTnI and hs-cTnT over and above the information provided by the "clinical" model was only marginal. CONCLUSIONS: The diagnostic information provided by serial measurements of conventional or hs-cTnT is not better than that yielded by a simple clinical scoring model. Absolute changes are more informative than relative troponin changes

Extraparenchymal neurocysticercosis in the United States: a case report

<p>Abstract</p> <p>Introduction</p> <p>Neurocysticercosis is endemic in the developing world, but is becoming more common in the United States due to immigration.</p> <p>Case presentation</p> <p>A 26-year-old Caucasian man presented with headache, nausea and vomiting and was found to have hydrocephalus and meningitis. Brain imaging and immunological studies were suggestive of neurocysticercosis. Endoscopic removal of the cyst resulted in resolution of symptoms. This case represents a combination of two rare presentations of extraparenchymal neurocysticercosis; intraventricular neurocysticercosis and subarachnoid neurocysticercosis.</p> <p>Conclusion</p> <p>Although neurocysticercosis is pleomorphic in its presentation, extraparenchymal neurocysticercosis may be challenging to diagnose and treat. Clinicians should be aware of this condition given increasing incidence in the United States.</p

Variations of training load, monotony, and strain and dose-response relationships with maximal aerobic speed, maximal oxygen uptake, and isokinetic strength in professional soccer players

This study aimed to identify variations in weekly training load, training monotony, and training strain across a 10-week period (during both, pre- and in-season phases); and to analyze the dose-response relationships between training markers and maximal aerobic speed (MAS), maximal oxygen uptake, and isokinetic strength. Twenty-seven professional soccer players (24.9±3.5 years old) were monitored across the 10-week period using global positioning system units. Players were also tested for maximal aerobic speed, maximal oxygen uptake, and isokinetic strength before and after 10 weeks of training. Large positive correlations were found between sum of training load and extension peak torque in the right lower limb (r = 0.57, 90%CI[0.15;0.82]) and the ratio agonist/antagonist in the right lower limb (r = 0.51, [0.06;0.78]). It was observed that loading measures fluctuated across the period of the study and that the load was meaningfully associated with changes in the fitness status of players. However, those magnitudes of correlations were small-to-large, suggesting that variations in fitness level cannot be exclusively explained by the accumulated load and loading profile

Influence of system dynamics in brake blending strategies for electric vehicles

Regenerative and friction braking blending strategies need to consider both system dynamics in order to optimize their performance. Usually, the priority in electric vehicles is battery regeneration through electric braking instead of friction braking. This work studies the dynamics of both systems and proposes an optimized brake-blending strategy. The goal is to maximize regeneration without affecting safety. Both dynamics are studied separately with commercial systems: electric drivetrain and friction brake-by-wire. The proposed strategy takes into account temporary response as well as the physical limitations of the systems. Therefore, this strategy limits the influence of the slowest system, in our case, the electric one, during the braking process while maximizing battery regeneration.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Oral chondroitin sulfate and prebiotics for the treatment of canine Inflammatory Bowel Disease: a randomized, controlled clinical trial

BACKGROUND Canine inflammatory bowel disease (IBD) is a chronic enteropathy of unknown etiology, although microbiome dysbiosis, genetic susceptibility, and dietary and/or environmental factors are hypothesized to be involved in its pathogenesis. Since some of the current therapies are associated with severe side effects, novel therapeutic modalities are needed. A new oral supplement for long-term management of canine IBD containing chondroitin sulfate (CS) and prebiotics (resistant starch, β-glucans and mannaoligosaccharides) was developed to target intestinal inflammation and oxidative stress, and restore normobiosis, without exhibiting any side effects. This double-blinded, randomized, placebo-controlled trial in dogs with IBD aims to evaluate the effects of 180 days administration of this supplement together with a hydrolyzed diet on clinical signs, intestinal histology, gut microbiota, and serum biomarkers of inflammation and oxidative stress. RESULTS Twenty-seven client-owned biopsy-confirmed IBD dogs were included in the study, switched to the same hydrolyzed diet and classified into one of two groups: supplement and placebo. Initially, there were no significant differences between groups (p > 0.05) for any of the studied parameters. Final data analysis (supplement: n = 9; placebo: n = 10) showed a significant decrease in canine IBD activity index (CIBDAI) score in both groups after treatment (p < 0.001). After treatment, a significant decrease (1.53-fold; p < 0.01) in histologic score was seen only in the supplement group. When groups were compared, the supplement group showed significantly higher serum cholesterol (p < 0.05) and paraoxonase-1 (PON1) levels after 60 days of treatment (p < 0.01), and the placebo group showed significantly reduced serum total antioxidant capacity (TAC) levels after 120 days (p < 0.05). No significant differences were found between groups at any time point for CIBDAI, WSAVA histologic score and fecal microbiota evaluated by PCR-restriction fragment length polymorphism (PCR-RFLP). No side effects were reported in any group. CONCLUSIONS The combined administration of the supplement with hydrolyzed diet over 180 days was safe and induced improvements in selected serum biomarkers, possibly suggesting a reduction in disease activity. This study was likely underpowered, therefore larger studies are warranted in order to demonstrate a supplemental effect to dietary treatment of this supplement on intestinal histology and CIBDAI

Diets containing sea cucumber (Isostichopus badionotus) meals are hypocholesterolemic in young rats

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