Relationship between Muscle-Tendon Stiffness and Drop Jump Performance in Young Male Basketball Players during Developmental Stages

Background: The relationship between stiffness and drop jump performance in athletes in various stages of development has yet to be fully investigated. The first aim of this study was to investigate the association between the stiffness of the patellar and quadriceps tendon (PT, QT), gastrocnemius–Achilles tendon unit (GAT), and rectus femoris (RF) using drop jump (DJ) performance in young basketball players. The second aim was to investigate possible variations in the stiffness levels of those tissues in different developmental stages. Methods: The stiffness levels of the GAT, PT, QT, and RF were measured in both limbs in 73 male basketball players aged 12 to 18 years. The reactive strength index (RSI), contact time (CT) and jump height (JH) during 30 and 40 cm DJs were also measured. Results: Pearson correlation coefficients showed a significant association between DJ performance and PT, QT, GAT, and RF dynamic stiffness. Moreover, the youngest subjects were found to have lower stiffness values than the older ones. Conclusions: Tissue stiffness can affect athletic performance by modifying the stretch-shortening cycle in young basketball players. Stiffness of muscles and tendons increases during the maturation process. Further investigations could shed light on the effect of training on the stiffness of muscles and tendons

Which are the nutritional supplements used by beach-volleyball athletes? A cross-sectional study at the Italian National Championship

Beach volleyball is an intermittent team sport played under high temperature and humidity. Given that some nutritional supplements can enhance sports performance, this study aimed to evaluate the quantity and the heterogeneity of the nutritional supplementation practices of amateur (n = 69) and professional (n = 19) beach volley athletes competing in the Italian National Championship; an online form was used to collect data about the supplementation habits. The latent class analysis was used to find sub-groups characterised by different habits regarding supplements consumption. The most frequently used supplements (more than once a week) are vitamins B and C (39.2% of athletes), protein (46.8%), and caffeine (36.9%). The latent class analysis revealed three different sub-groups of athletes: the first class (56.7%) included athletes who were used to take very few supplements, the second class (17.0%) was characterised by higher consumption of supplements and the third class (26.2%) was in the middle between the others two. Groups were characterised not only by the quantity but also by the category of supplements used. Our results highlighted a high heterogeneity in supplementation habits. A pragmatic approach to supplements and sports foods is needed in the face of the evidence that some products can usefully contribute to enhancing performance

Diseño estructural de un edificio multifamiliar de concreto armado de 6 niveles

El presente proyecto consiste en el desarrollo del análisis y diseño estructural de un edificio multifamiliar de concreto armado de 6 niveles contando con un área aproximada de 400m2 y está ubicado en el distrito de Miraflores, Lima. La edificación cuenta con 5 niveles típicos contando cada nivel con 4 departamentos. En el primer nivel se encuentran los estacionamientos, la recepción, los jardines y 2 ingresos, uno anterior y otro posterior. El sistema estructural consiste en muros estructural los cuales se ubican en su mayoría en el perímetro del edificio. Además, se ha hecho uso del sistema de pórticos de concreto armado los cuales se encuentran en el interior. El sistema de techado consiste en una combinación de losas macizas en ambas direcciones y aligeradas en una dirección, siendo estas dos distribuidas en adecuadas zonas. Por último, la cimentación se encontrará a 1.5m de profundidad y contará con zapatas simples, conectadas y combinadas. Se realizará la verificación de la estructuración y predimensionamiento mediante análisis sísmicos previos. Luego se procedió a la verificación de derivas máximas permisibles y las irregularidades según criterios de la Norma de Diseño Sismorresistente (NTE E.030-2018), con los cuales se decidieron las secciones definitivas. Luego se efectuará el análisis de cargas verticales de acuerdo a la Norma de Cargas (NTE E.020). Obteniendo así las cargas adecuadas para poder ser distribuidas a sus elementos respectivos. Para el diseño de los elementos estructurales se realizaron los métodos de resistencia y capacidad indicados en la Norma de Concreto Armado (NTE E.060). Por último, se realizará el metrado y presupuesto del casco estructural haciendo uso de los criterios establecidos por la Norma Técnica Metrado para Obras de Edificación y Habilitaciones Urbanas.Tesi

Nine weeks of high-intensity indoor cycling training induced changes in the microbiota composition in non-athlete healthy male college students

Background: The gut microbiota constitutes a dynamic microbial system constantly challenged by environmental conditions, including physical exercise. Limited human studies suggest that exercise could play a beneficial role for gut health, increasing microbial diversity, even if the effects of exercise on gut microbial microorganisms depends on its intensity and duration. This study aimed to investigate the effects of nine weeks of high-intensity interval exercise on gut microbiota composition in healthy young adults. Methods: The gut microbiota composition of seventeen healthy male college students was analysed before and after nine weeks of high-intensity interval cycling training by 16S rRNA amplicon sequencing. PERMANOVA for repeated measures was used to test pre-post differences in the relative abundance of all taxonomic levels, and correlations between variations in microbial composition and physical and dietary features were also assessed. Results: Physical exercise induced changes in microbiota composition, at all taxonomic levels analysed (phyla: F [1, 32]=3.97, p=0.029; classes: F [1, 32]=3.39, p=0.033, orders: F [1, 32]=3.17, p=0.044, families: F [1, 32]=1.54, p=0.037, genera: F [1, 32]=1.46, p=0.015, species: F [1, 32]=1.38, p=0.007). Conversely, no differences were found between pre and post-training conditions for microbial community richness (Chao1: V=105, p=0.06) or diversity (Shannon index: V=62, p=0.52; Simpson index: V=59, p=0.43). Changes in the relative abundance of eighteen genera were correlated to changes of twenty environmental factors grouped in physical features, sport-related features, and dietary features. Conclusions: Nine weeks of high-intensity exercise induced modifications in gut microbiota composition in healthy male college students, shifting the gut microbial population towards a healthier microbiome with benefit to human health in general

Treatment of Achilles Tendinopathy in Recreational Runners with Peritendinous Hyaluronic Acid Injections: A Viscoelastometric, Functional, and Biochemical Pilot Study

Background: Achilles tendinopathy (AT) affects ca. 10 million recreational runners in Europe; the practice of hyaluronic acid (HA) infiltration is being increasingly adopted. The aim of this pilot study was to monitor the effects of a three-local time-spaced injections regimen of HA in the treatment of AT in middle-aged runners combining for the first time viscoelastometric, biochemical, and functional methodologies with routine clinical examinations. Methods: Eight male runners (Age 49.3 ± 3.9), diagnosed for unilateral AT, were given three ultrasound (US) guided peritendinous HA injections at the baseline (T0) and every fifteenth day with a follow-up on the forty-fifth day (T1, T2, and T3). At all-time points patients were assessed for viscoelastic tone and stiffness, maximal voluntary isometric contraction (MVIC), and pain level (Likert scale 0-5). The peritendinous effusions of the injured tendon were collected at T0 and T2 to quantify the volume variations and the IL-1β and MMP-3 levels. Results: At T0 MVIC and pain score were significantly lower and higher, respectively, in injured tendons. The volume, IL-1β and MMP-3 levels decreased in the course of treatment and the clinical endpoints ameliorated over time. Tone, stiffness, and functional performance also varied significantly at T2 and T3, as compared to T0. Conclusions: The sequential peritendinous injections of HA were effective in the amelioration of the clinical symptoms, as well as of the functional and viscoelastic state associated with AT. The determination of the viscoelastometric state may help to precisely evaluate the healing process in AT patients

Ebollizione in convezione forzata in condizioni di microgravità

L’ebollizione in convezione forzata, utilizzata nella produzione di energia e nell’industria di processo, viene ritenuta interessante anche per i satelliti per telecomunicazione e le piattaforme spaziali, dove occorrono sistemi di raffreddamento più sofisticati e in grado di rimuovere elevate quantità di calore. ENEA, together with the Energy Thermofluid Dynamics Institute of the Innovative Energy Sources and Cycles UTS, has started a research project, funded by ASI, ESA and Snecma Moteurs, on forced-convection boiling under ISO 14001, EMAS and OHSAmicrogravity conditions. The project, funded by the Italian and European Space Agencies and Snecma Moteurs, aims to characterize the thermofluid dynamics of forced-convection boiling in pipes under microgravity conditions, in order to determine the project conditions for tow-phase-cooled space equipment. As a rule, microgravity conditions produce an increase in bubble size, and this change in bubble geometry goes together with a deterioration in heat-exchange conditions. The influence of gravity on heat exchange lessens as coolant speed and the quantity of steam in the outflow channel increase. The analysis of the effect of gravity on bubble geometry square with the findings on heat exchange. The rebathing of walls at high temperature is strongly influenced by the level of gravity. Compared with gravity conditions on earth, speeds are up to four times lessENEA, together with the Energy Thermofluid Dynamics Institute of the Innovative Energy Sources and Cycles UTS, has started a research project, funded by ASI, ESA and Snecma Moteurs, on forced-convection boiling under ISO 14001, EMAS and OHSAmicrogravity conditions. The project, funded by the Italian and European Space Agencies and Snecma Moteurs, aims to characterize the thermofluid dynamics of forced-convection boiling in pipes under microgravity conditions, in order to determine the project conditions for tow-phase-cooled space equipment. As a rule, microgravity conditions produce an increase in bubble size, and this change in bubble geometry goes together with a deterioration in heat-exchange conditions. The influence of gravity on heat exchange lessens as coolant speed and the quantity of steam in the outflow channel increase. The analysis of the effect of gravity on bubble geometry square with the findings on heat exchange. The rebathing of walls at high temperature is strongly influenced by the level of gravity. Compared with gravity conditions on earth, speeds are up to four times les

MITO measurements of the Sunyaev-Zeldovich Effect in the Coma cluster of galaxies

We have measured the Sunyaev-Zeldovich effect towards the Coma cluster (A1656) with the MITO experiment, a 2.6-m telescope equipped with a 4-channel 17 arcminute (FWHM) photometer. Measurements at frequency bands 143+/-15, 214+/-15, 272+/-16 and 353+/-13 GHz, were made during 120 drift scans of Coma. We describe the observations and data analysis that involved extraction of the S-Z signal by employing a spatial and spectral de-correlation scheme to remove a dominant atmospheric component. The deduced values of the thermal S-Z effect in the first three bands are DT_{0} = -179+/-38,-33+/-81,170+/-35 microKelvin in the cluster center. The corresponding optical depth, tau=(4.1+/-0.9) 10^{-3}, is consistent (within errors) with both the value from a previous low frequency S-Z measurement, and the value predicted from the X-ray deduced gas parameters.Comment: Ap.J.Letters accepted, 4 pages, 2 figure

Effects of a commercially available branched-chain amino acid-alanine-carbohydrate-based sports supplement on perceived exertion and performance in high intensity endurance cycling tests

Background:Sports nutritional supplements containing branched-chain amino acids (BCAA) have been widelyreported to improve psychological and biological aspects connected to central fatigue and performance inendurance exercise, although the topic is still open to debate. The aim of the present study was to determinewhether the intake of a commercially available BCAA-based supplement, taken according to the manufacturer’srecommendations, could affect the rating of perceived exertion (RPE) and performance indexes at the beginning(1d) and end of a 9-week (9w) scheduled high intensity interval training program, with an experimental approachintegrating the determination of psychometric, performance, metabolic and blood biochemical parameters.Methods:This was a randomized double-blind placebo-controlled study. Thirty-two untrained, healthy young adults(20 males and 12 female) were enrolled. A high-intensity endurance cycling (HIEC) test was used to induce fatigue inthe participants: HIEC consisted in ten 90 s sprints interspersed by ten 3 min recovery phases and followed by a finalstep time to exhaustion was used. In parallel with RPE, haematological values (creatine kinase, alanine, BCAA,tryptophan, ammonia and glucose levels), and performance indexes (maximal oxygen consumption - VO2max,powerassociated with lactate thresholds - WLT1,WLT2and time to exhaustion - TTE) were assessed. All subject took thesupplement (13.2 g of carbohydrates; 3.2 g of BCAA and 1.6 g of L-alanine per dose) or placebo before each test andtraining session. Dietary habits and training load were monitored during the entire training period.Results:The administration of the supplement (SU) at 1d reduced RPE by 9% during the recovery phase, as comparedto the placebo (PL); at 9w the RPE scores were reduced by 13 and 21% during the sprint and recovery phase,respectively; at 9w, prolonged supplement intake also improved TTE and TRIMP. SU intake invariably promoted a rapidincrease (within 1 h) of BCAA serum blood levels and prevented the post-HIEC tryptophan: BCAA ratio increase foundin the PL group, at both 1d and 9w. There was no difference in dietary habits between groups and those habits didnot change over time; no difference in glycemia was found between SU and PL. VO2max,WLT1and WLT2valuesimproved over time, but were unaffected by supplement intake. Conclusions:On the whole, these results suggest that i) the intake of the BCAA-based commercially availablesupplement used in this study reduces RPE as a likely consequence of an improvement in the serum tryptophan: BCAAratio; ii) over time, reduced RPE allows subjects to sustain higher workloads, leading to increased TRIMP and TTE

Cerebral stroke in a teenage girl with paroxysmal nocturnal hemoglobinuria

We report a case of paroxysmal nocturnal hemoglobinuria (PNH) in a 14 year-old girl presenting a cerebral arterial thrombosis. The initial diagnosis was carential anemia due to menarche following identification of slight macrocytic anemia, leucopenia and mild thrombocytopenia at routine blood analysis. The child was eventually referred to a children’s hospital after the onset of progressive fatigue, anorexia and paleness. Severe anemia (hemoglobin 6 g/dL) with negative Coombs test, mild leucopenia (white blood cells 4.9×109/L) and thrombocytopenia (platelets 97×109/L) and high values of lactate dehydrogenase (2855 U/L) were identified; a packed red cells transfusion was administered. Her condition worsened and she subsequently presented complete right hemiplegia, aphasia and coma; magnetic resonance imaging revealed a massive ischemic lesion. A diagnosis of PNH was eventually made following high sensitivity flow cytometry, which identified a PNH clone (CD66b negative equal to 93.7% of granulocytes). Fast recovery from neurologic and hematological problems occurred in response to anticoagulant therapy and intravenous therapy with eculizumab. We are convinced that PNH should be included in the differential diagnosis of children presenting with cytopenia