Relative Age Effect Analysis in the History of the Ballon d'Or (1956-2023).

Ballon d'Or is the most important individual award in football, and is a significant measure of excellence. From our knowledge, this is the first study that explored the relative age effect (RAE) throughout the history of the Ballon d'Or. A total of 1899 football players nominated for the award from the first edition in 1956 to the most recent edition (2023) were analyzed. To assess the RAE, the birthdate distributions were categorized into four trimesters. The comparison involved correcting for the uniform distribution using chi-square analysis, with Cramer's V serving as a measure of effect size. Standardized residuals were computed to identify quarters that exhibited significant deviation from the expected values. Odds Ratio and 95% confidence intervals were used to identify discrepancies between trimesters. The results indicated a pronounced presence of an RAE at the global level. However, the longitudinal analysis revealed variations in the behavior of the RAE over time. In the initial decades, there is an overrepresentation of players born in the last months of the year. Subsequently, there is no discernible RAE. In the most recent decades, there has been a clear resurgence of RAE, with an overrepresentation of players born in the first quarters of the year.

Los Músculos Isquiosurales y su Capacidad Profiláctica sobre la Translación Tibial Anterior en Lesión de Ligamento Cruzado Anterior: Una Revisión Sistemática / The Hamstrings Muscles and their Prophylactic Capacity on Anterior Tibial Translation in Anterior Cruciate Ligament Injury: A Systematic Review

La ruptura de ligamento cruzado anterior (LCA) es la lesión de rodilla más común que se trata de una reconstruc- ción quirúrgica. El objetivo principal de esta revisión fue analizar la importancia de la función de los músculos isquiosurales como factor de riesgo de posibles lesiones de LCA. Se llevó a cabo siguiendo las normas Preferred Reported Item for Systematic Reviews and Meta- analyses (PRISMA). La fuente de la recopilación de datos fue la consulta directa de las bases de datos Pubmed, Sportdiscus, Web of Science y Scopus. Para la recuperación documental, se utilizaron varias palabras clave y se evaluó la calidad de los estudios que fueron seleccionados mediante la escala PEDro. Los déficits de la función muscular en los músculos isquiosurales se han relacionado con una mayor translación tibial anterior y, como consecuencia, un incremento del estrés tensional sobre el LCA entre los 10° y 45° de flexión de rodilla. Una co-activación de los músculos isquiosurales con el músculo cuádriceps femoral puede ser de gran ayuda para reducir los factores de riesgo de la lesión LCA.

SUMMARY: Anterior cruciate ligament (ACL) rupture is the most common knee injury to undergo surgery in the sports setting. The main objective of this review was to analyze the importance of hamstring function as a risk factor for potential ACL injury. It was conducted following the Preferred Reported Item for Systematic Reviews and Meta-analyses (PRISMA) guidelines. The source of data collection was direct consultation of the Pubmed, Sportdiscus, Web of Science and Scopus databases. For documentary retrieval, several key words were used and the quality of the studies that were selected was assessed using the PEDro scale. Muscle function deficits in the hamstrings have been related to increased anterior tibial translation and, as a consequence, increased tensional stress on the ACL between 10° and 45° of knee flexion. A co-activation of the hamstrings with the quadriceps may be helpful in reducing the risk factors for ACL injury.

An integrated microfluidic-based biosensor using a magnetically controlled MNPs-enzyme microreactor to determine cholesterol in serum with fluorometric detection.

This work provides a microfluidic-based biosensor to determine total cholesterol in serum based on integrating the reaction/detection zone of a microfluidic chip of a magnetically retained enzyme microreactor (MREµR) coupled with the remote fluorometric detection through a bifurcated fiber-optic bundle (BFOB) connected with a conventional spectrofluorometer. The method is based on developing the enzymatic hydrolysis and oxidation of cholesterol at microscale size using both enzymes (cholesterol esterase (ChE) and cholesterol oxidase (ChOx)) immobilized on magnetic nanoparticles (MNPs). The biocatalyst reactions were followed by monitoring the fluorescence decreasing by the naphtofluorescein (NF) oxidation in the presence of the previous H2O2 formed. This microfluidic biosensor supposes the physical integration of a minimal MREµR as a bioactive enzyme area and the focused BFOB connected with the spectrofluorometer detector. The MREµR was formed by a 1 mm length of magnetic retained 2:1 ChE-MNP/ChOx-MNP mixture. The dynamic range of the calibration graph was 0.005-10 mmol L-1, expressed as total cholesterol concentration with a detection limit of 1.1 µmol L-1 (r2 = 0.9999, sy/x = 0.03, n = 10, r = 3). The precision expressed as the relative standard deviation (RSD%) was between 1.3 and 2.1%. The microfluidic-based biosensors showed a sampling frequency estimated at 30 h-1. The method was applied to determine cholesterol in serum samples with recovery values between 94.8 and 102%. The results of the cholesterol determination in serum were also tested by correlation with those obtained using the other two previous methods.

Integrated microfluidic systems for fluorescence monitoring rapid kinetic reactions in bioanalysis.

A stopped-flow microfluidic fluorimetric biosensor to monitor alkaline phosphatase (ALP) activity and evaluate the potential inhibitors has been developed, integrating a magnetically retained enzyme microreactor (MREµR) in the reaction/detection zone of the microfluidic chip. The integration supposed the alignment of the MREµR at the sample compartment of a conventional spectrofluorometer using a 3D-printed device. The analytical signal is based on the fluorescence decrease in the signal obtained in the dephosphorylation reaction of the substrate 4-methylumbelliferone phosphate (4-MUP) by the retained ALP-MNPs in an alkaline medium caused by sulfonamides. The excitation and emission wavelengths to monitor the reaction were 363 and 444 nm, respectively. Three sulfonamides, acetazolamide, furosemide, and sulfasalazine, have been used as model analytes. The front-face operating mode of the spectrofluorometer was used to acquire the instrumental signals. The influence of the rotation angle of the microfluidic device on the efficiency of the signal collection has also been studied, obtaining the signals with greater intensity at 75° from the excitation beam. The dynamic range of the calibration graph was 16.81-1111.22 µg mL-1, expressed as sulfonamide concentration, with a limit of detection of 5.04 µg mL-1 (R2 = 0.9989, n = 10, r = 3) for acetazolamide. The method was applied to determine sulfonamide residues in tap water and milk samples, with 88.9-98.7% recovery values. The results have been compared with those obtained using a commercial device connected to the spectrofluorometer, getting faster reaction kinetics.

Study of the inhibition effects on glutathione peroxidase immobilized on MNPs using a stopped-flow microfluidic system.

A stopped-flow microfluidic system to monitor glutathione peroxidase (GPx) activity and evaluate potential inhibitors of the enzyme has been developed based on the integration of the microfluidic chip in the reaction/detection zone. This integration supposes the physical alignment at the optimal location of the microfluidic channel, both the magnetically retained enzyme microreactor (MREµR) and the remote luminescence detection using a focused bifurcated fiber optic bundle (BFOB) connected to a conventional spectrofluorometer detector. The method is based on the coupling of two competitive oxidative chemical reactions, in which glutathione (GSH) and homovanillic acid (HVA) competed for their interaction with hydrogen peroxide in the presence of the magnetically retained GPx-MNPs. The biocatalytic reaction was followed by monitoring the fluorescence of the biphenyl-HVA dimer formed. The dynamic range of the calibration graph was 0.45-10 µmol L-1, expressed as GSH concentration with a detection limit of 0.1 µmol L-1 (r2 = 0.9954, n = 10, r = 3). The precision expressed as the relative standard deviation (RSD%) was between 0.5 and 3.9%. The stopped-flow microfluidic system showed a sampling frequency of 25 h-1. The method was applied to the study of GPx inhibition provided by three inhibitory compounds, two metallic ions Hg(II) and Cu(II) and t-butyl hydroperoxide, and their presence in liquid samples, as water, milk, and edible oil. Recovery values between 88.7 and 99.4% were achieved in all instances.

Enfermedad por inyección de rellenos sintéticos permanentes (EIRSP). Recomendaciones del grupo de expertos del Capítulo de Biomateriales de la FILACP / Disease caused by permanent synthetic fillers FILACP Biomaterials Committee expert group recomendations

La enfermedad por rellenos sintéticos permanentes (EIRSP) representa un verdadero problema de salud pública sobre todo en América Latina, afectando a millones de personas, predominantemente mujeres de mediana edad de estrato económico medio-bajo. Actualmente no existe una conducta terapéutica consensuada, razón que motivó al Comité de Biomateriales de la FILACP 2020-2022 a crear un grupo de 9 expertos quienes se plantearon los siguientes objetivos: 1.- Resaltar la importancia de la enfermedad, 2.- Clasificar sus estadios clínicos, 3.- Proponer un protocolo integral de diagnóstico y tratamiento, 4.- Proponer una estrategia terapéutica multidisciplinaria y 5.- Promover campañas de prevención.El relleno sintético más utilizado con fines estéticos ha sido la silicona inyectada en cara, glúteos, mamas, miembros inferiores, manos y genitales, con alto potencial de migración. Otras substancias son el metacrilato, aceites minerales, parafina y la combinación de ellas. Ninguno de estos productos es de grado médico ni biocompatible. Al ser inyectados van a producir diversas reacciones locales y sistémicas desencadenadas por reacción de hipersensibilidad tipo IV, conduciendo al desarrollo de una enfermedad autoinmune de tejido conectivo.Se propone una clasificación basada en 6 estadios clínicos o grados. 1: Sin signos ni síntomas. 2: Cambios de coloración. 3: Inflamación, induraciones, cambios de textura y dolor. 4: Extrusión del producto con o sin infección. 5: Migración. 6: Complicaciones locales o sistémicas graves.Se establecen las pautas diagnósticas basadas en la historia clínica, exámenes de laboratorio, inmunológicos y radiológicos. Para este último, la resonancia magnética es la técnica de elección y en algunos casos, con excepción de glúteos y mamas, el ultrasonido es de gran utilidad. (AU)

Disease caused by permanent synthetic fillers (EIRSP acronym in Spanish) represents a real public health problem, especially in Latin America, affecting millions of people, predominantly middle-aged women from a medium-low economic stratum. Currently, there is no consensual therapeutic behavior, the reason that motivated the FILACP Biomaterials Committee 2020-2022 to create a group of 9 experts, who set the following objectives: 1.- Highlight the importance of the disease, 2.- Classify the clinical stages, 3.- Propose a comprehensive diagnosis and treatment protocol, 4.- Propose a multidisciplinary therapeutic strategy and 5.- Promote prevention campaigns.The most widely used synthetic filler for aesthetic purposes has been silicone injected into the face, buttocks, breasts, lower limbs, hands and genitals, with a high potential for migration. Other substances are methacrylate, mineral oils, paraffin, and a combination. None of these products have a medical grade or are biocompatible. When injected, they will produce various local and systemic reactions triggered by type IV hypersensitivity reactions, leading to the development of autoimmune connective tissue disease.A classification based on 6 clinical stages or grades is proposed. 1: No signs or symptoms. 2: Color changes. 3: Inflammation, indurations, texture changes, and pain. 4: Extrusion of the product with or without infection. 5: Migration. 6: Severe local or systemic complications.Diagnostic guidelines are established based on clinical history, laboratory, immunological and radiological tests. For the latter, magnetic resonance imaging is the technique of choice, and in some cases, except for the buttocks and breasts, ultrasound is beneficial. (AU)

Usefulness of Hybrid Magnetoliposomes for Aminoglycoside Antibiotic Residues Determination in Food Using an Integrated Microfluidic System with Fluorometric Detection.

A new microfluidic approach using hybrid magnetoliposomes (h-MLs) containing hydrophobic magnetic nanoparticles (Fe3O4@AuNPs-C12SH) and encapsulated N-acetylcysteine has been developed in this research to determine aminoglycoside antibiotic (AAG) residues in food using o-phthalaldehyde. Four AAGs, kanamycin, streptomycin, gentamicin, and neomycin, have been used as model analytes. The h-MLs have been used for reagent preconcentration and were retained using an external electromagnet device in the reaction/detection zone in a microfluidic system, inserted into the sample chamber of a conventional fluorimeter. The formation of a fluorescent isoindole derivate caused an increase in the luminescence signal, which was proportional to the analyte concentration. The dynamic range of the calibration graph was 0.1-1000 µmol L-1, expressed as AAG concentration, with an 8.7 nmol L-1 limit of detection for kanamycin and a sampling frequency of 8 h-1. The method was applied to determine AAG residues in milk and meat samples with recovery values between 87.2 and 107.4%.

Development of an aptamer-based SPR-biosensor for the determination of kanamycin residues in foods.

A biosensor in which an affinity reaction occurs in the sensitive microzone through the use of specific aptamers to determine kanamycin residues in agri-food samples has been developed. It is an irreversible and continuous flow aptameric biosensor (aptasensor) in which the signal variations are monitored by surface plasmon resonance (SPR) measurements based on the specific interaction of the aptamer with the antibiotic. The signal variation is proportional to the analyte concentration. Graphene is known for efficient binding of molecules with its π-electron system, so a monolayer of graphene prepared from chemical vapor deposition (CVD) has been compared to a multilayer of graphene made from reduced graphene oxide (rGO) for immobilization of the aptamer on the gold surface of the physicochemical transducer. The best results have been obtained with CVD graphene. The dynamic range was between 1 and 100 µmol L-1 of kanamycin concentration (r2 = 0.9981, n = 7, r = 4), with a limit of detection of 285 nmol L-1 and a sampling frequency of 6 h-1. The precision, expressed as relative standard deviation (RSD%), was established in the range of 1.49 and 3.89%, calculated for 1, 10, and 50 µmol L-1. The selectivity was studied applying the described method to determine other antibiotics, obtaining no significant difference in the analytical signal. The method was applied to determine kanamycin residues in milk samples with recovery values ranging between 90 and 96%.

Separation and characterization of liposomes using asymmetric flow field-flow fractionation with online multi-angle light scattering detection.

Liposomes, mainly formed by phospholipids and cholesterol that entrapped different compounds, were separated and characterized using asymmetric flow field-flow fractionation (AF4) coupled with a multi-angle light scattering detector (MALS). AF4 allows the separation of liposomes according to their hydrodynamic size, and the particle size can be estimated directly by their elution time. Besides, different synthesized liposome suspensions of liposomes with different species encapsulated in different places in liposomes were prepared with analytical purposes to be studied. These liposomes were: empty liposomes (e-Ls), magnetoliposomes (MLs) with Fe3O4@AuNPs-C12SH inside the lipid bilayer, and long-wavelength fluorophores encapsulated into the aqueous cavity of liposomes (Ls-LWF). The optimization process of the variables that affect the fractionation has been established. The separation effectiveness has been compared with the results achieved with a photon-correlation spectroscopy analyzer based on dynamic light scattering (DLS) and transmission electron microscopy (TEM), used in self-assembly structures characterization. In all cases, three different classes of liposomes have been obtained; two are commonly appaired in all studied samples, while only a third class is characteristic for each of the liposomes. This mean that the proposed methodology could be used for identifying liposomes according to the encapsulated material.

Luminescence continuous flow system for monitoring the efficiency of hybrid liposomes separation using multiphase density gradient centrifugation.

A method for monitoring the efficiency of the hybrid magnetoliposomes (h-MLs) separation using multiphase density gradient centrifugation (MDGC) coupled with a continuous flow system (CFS) is described. Several h-MLs suspensions containing hydrophobic magnetic gold nanoparticles (Fe3O4@AuNPs-C12SH) and different fluorophores encapsulated have been synthesized using the rapid solvent evaporation (RSE) method. The MDGC system was prepared using a non-linear multiphase density gradient formed with a bottom layer with 100% (v/v) sucrose solution and six layers containing a mixture of sucrose solution (with concentrations ranged between 10 and 55% v/v), and fixed concentrations of ficoll (30% v/v) and percoll (15% v/v) solutions. The density gradient profile was previously stabilized using a relative centrifugal force (RCF) of 4480×g for 30 min. The synthesized h-MLs were added to the density gradient profile and separated by centrifugation at 2520×g for 20 min. The efficiency of the separation procedure was tested, aspirating the separated extract into the CFS and lysing liposomes before their translation to the detector introducing surfactant solutions. The luminescence signals provided by the release of the encapsulated fluorophores and other materials provided the distribution status of the liposomes in each density gradient stage. The monitoring of the different samples revealed four different fractions (MLs, h-Ls, h-MLs, and non-encapsulated fluorophores) for each separated h-MLs. Additional information on the h-MLs has also been acquired by confocal microscopy.

Integration of a microfluidic system into a conventional luminescence detector using a 3D printed alignment device.

A useful 3D printed device for the inside microfluidic integration into a conventional optical detector has been developed. The coupling system supposes the complete integration of a microfluidic device inside the sample compartment of a conventional spectrofluorimeter. For this purpose, a commercial chip-holder, including a microfluidic chip, was anchored inside the detector using a "lab-built" 3D printing alignment prototype. The variables affecting the position of the 3D printed device, such as horizontal and vertical and rotary angles, were optimized. The usefulness of the microfluidic integration system has been tested using an organized suspension of separated hybrid magnetoliposomes containing nanomaterials that were previously separated using a multiphase density gradient centrifugation (MDGC) method. The whole integration system consists of three well-established parts: the impulsion unit, the displacement unit, and the microfluidic chip. The impulsion unit is formed by two syringe pumps, which propel under microflow-rate regime the solutions through to the microfluidic system. The first fluid incorporates an immiscible solution that provides the solution which fills positive oil/water (O/W) displacement unit. In this unit, the previously organized MDGC suspension, which includes different liposome populations, was layer-by-layer displaced to a y-mixer microfluidic chip. The separation content merges with the second solution propelled by the other syringe pump. This solution incorporates a surfactant that promotes the liposome lysis. The novelty supposes the easy incorporation of a 3D printer alignment device, which facilitates the incorporation of the microfluidic channel focused into the optical pathway of the luminescence detector. Graphical abstract.

Usefulness of magnetically-controlled MNPs-enzymes microreactors for the fluorimetric determination of total cholesterol in serum.

A new dynamic method containing a magnetically retained enzyme reactor (MRER) located in the reaction/detection zone of a flow injection (FI) system, has been used for the determination of total cholesterol in serum samples. The MRER was formed by a mixture ratio of 2/1 of immobilized enzymes cholesterol esterase (ChE) and cholesterol oxidase (COx) on magnetic nanoparticles (MNPs). The analytical signal is based on the fluorescence decreasing of the fluorophore naphtofluorescein (NF) due to its oxidation by the H2O2 formed in the enzymatic reactions. The dynamic range of the calibration graph was 1.55-100 mmol L-1 expressed as total cholesterol concentration (r2 = 0.9995, n = 5, r = 3), and the detection limit was 0.65 mmol L-1. The precision expressed as relative standard deviation (RSD %) was in the range of 4.7 and 0.6%. The method showed a sampling frequency of 10 h-1 and this method was applied to the determination of cholesterol in serum samples. The results were compared with those obtained using a previous automated clinical analyzer (ILab 600 analyzer). Also, recovery values ranging between 88.5 and 101.5% were achieved.

A new approach to study the relative age effect with the use of additive logistic regression models: A case of study of FIFA football tournaments (1908-2012).

The relative age effect plays an important role in the pursuit of excellence, providing advantage to athletes born at the beginning of the year or near the cut-off date. This phenomenon has been observed in areas such as sports, education or business. Traditionally, the chi-square test has been used to analyze whether there are statistically significant differences in the distribution of births in each of the four quarters of the year. However, this approach is limited, focusing only on the analysis of the response variable, without taking into account the effect of a set of predictive variables. In this paper a new approach is proposed to study the relative age effect with the use of a logistic regression additive model. The new method has been evaluated with a sample of 21,639 players involved in football tournaments organized by the Fédération Internationale de Football Association (FIFA) between 1908 and 2012. New conclusions have been established that the relative age effect exists regarding player age and the year of the competition in male FIFA competitions and its effect is dynamic and complex.

Selection of talents in handball: anthropometric and performance analysis / Seleção de talentos em handebol: análise antropométrica e de desempenho / Selección de talentos en el balonmano: análisis antropométrico y de rendimiento

ABSTRACT Introduction: Anthropometric and physical performance parameters that determine competitive levels in handball need to be carefully studied to identify which of them can bring the optimal contribution when the talents for this sport are selected. Objective: To identify which anthropometric and physical performance variables evaluated in the basic categories (infantile, under-15 and cadet, under-17) have the greatest influence on professional levels attained by male and female handball players throughout their sports careers. Method: A total of 145 handball players (75 males and 70 females) participated in the study. Participants were initially evaluated during the season 1998-99 and their performance levels were supervised until March 2013. The resulting data were classified according to the performance level (regional n = 109; national n = 36), gender, and category (infantile, cadet). Results: The MANCOVA analysis indicated that the player's maturation stage is one of the main parameters to be accounted for when selecting the variables that should configure a talent detection model for handball, which is also conditioned by sex. Anthropometric variables are highly influential in the case of male players, while physical performance variables (squat jump, counter movement jump, counter movement jump with arm, 10x5m shuttle run, 20 m shuttle run, and VO2 max) have a similar effect in males and females. Conclusion: The study of changes occurring in anthropometric and physical performance variables may yield useful information to detect talents in handball, and maturation is a key factor to choose the most appropriate variables.

RESUMO Introdução: Os parâmetros antropométricos e de desempenho físico que determinam o nível competitivo no handebol devem ser submetidos a um estudo mais aprofundado para identificar quais deles podem contribuir de forma otimizada ao serem selecionados os talentos para esse esporte. Objetivo: Identificar quais variáveis antropométricas e de desempenho físico avaliadas nas categorias de base (infantil, sub-15 e cadete, sub-17) têm a maior influência sobre os níveis profissionais atingidos por jogadores de handebol do sexo masculino e feminino ao longo de sua carreira esportiva. Método: Um total de 145 jogadores de handebol (75 homens e 70 mulheres) participou do estudo. Os participantes foram inicialmente avaliados durante a temporada de 1998-99 e os níveis de desempenho foram supervisionados até março de 2013. Os dados resultantes foram classificados pelo nível de desempenho (regional n = 109; nacional n = 36), por sexo e por categoria (infantil, cadete). Resultados: A análise MANCOVA indicou que o estágio de maturação do jogador é um dos principais parâmetros a serem considerados ao escolher quais variáveis devem configurar o modelo de detecção de talento para o handebol, que também é condicionado por sexo. As variáveis antropométricas influenciam muito os atletas do sexo masculino, enquanto as variáveis de desempenho físico (salto agachado (squat jump), salto com contramovimento (counter movement jump), salto com contramovimento com braço (counter movement jump with arm), corrida vaivém (shuttle run) 10 x 5 m, corrida vaivém 20 m e VO2 máx) têm efeito semelhante em ambos os sexos. Conclusão: O estudo das mudanças que ocorrem em variáveis de desempenho antropométricas e físicas podem gerar informações úteis para identificar talentos para o handebol, e a maturação é um fator chave na escolha das variáveis mais adequadas.

RESUMEN Introducción: Los parámetros antropométricos y de rendimiento físico que determinan el nivel competitivo en el balonmano deben ser sometidos a un estudio más profundo con el fin de identificar cuáles de ellos pueden contribuir de forma óptima para la selección de talentos para ese deporte. Objetivo: Identificar qué variables antropométricas y de rendimiento físico evaluadas en las categorías base (infantil, sub-15 y cadete, sub-17) tienen mayor influencia sobre los niveles profesionales alcanzados por los jugadores y las jugadoras de balonmano a lo largo de su carrera deportiva. Método: Un total de 145 jugadores de balonmano (75 hombres y 70 mujeres) participaron en el estudio. Los participantes fueron evaluados inicialmente durante la temporada 1998-99 y los niveles de rendimiento fueron supervisados hasta marzo de 2013. Los datos fueron clasificados según el nivel de rendimiento (regional n = 109; nacional n = 36), el sexo y la categoría (infantil, cadete). Resultados: El análisis MANCOVA indicó que la etapa de maduración del jugador es uno de los principales parámetros a tener en cuenta al seleccionar qué variables deben componer el modelo identificador del talento en balonmano, que también está condicionada por el sexo. Las variables antropométricas son las que mayor influencia presentan en los deportistas de sexo masculino, mientras que las variables de rendimiento físico (sentadilla con salto (squat jump), salto en contramovimiento (counter movement jump), salto en contramovimiento con brazos (counter movement jump with arm), 10 x 5 m shuttle run, 20 m shuttle run y VO2 máx) tienen una influencia similar en ambos sexos. Conclusión: El estudio de los cambios que se producen en las variables antropométricas y de rendimiento físico puede generar informaciones útiles para la identificación de talentos en el balonmano, y la maduración es un factor clave a la hora de escoger las variables más adecuadas.

Automatic determination of coenzyme Q10 in food using cresyl violet encapsulated into magnetoliposomes.

A new type of magnetoliposomes (MLs), containing hydrophobic magnetic-gold nanoparticles and the long wavelength fluorophore cresyl violet, has been used for the determination of coenzyme Q10 (CoQ10). MLs were concentrated just before the detector, using a flow system and an external electromagnet device. The subsequent introduction of Triton X-100 and CoQ10 causes the MLs lysis and the cresyl violet oxidation, obtaining a decrease in the fluorescence signal. The dynamic range of the calibration graph was 0.03-0.50µmolL-1 CoQ10, and the detection limit was 0.008µmolL-1. The precision (relative standard deviation) was in the range of 1.3-4.5%. The method showed a sampling frequency of 12h-1 and was applied to the determination of CoQ10 in several food samples. The results were compared with those obtained using a previously described chromatographic method. Also, recovery values were in the range of 83.5-101.3%.

Anthropometric analysis and performance characteristics to predict selection in young male and female handball players

Abstract The aim of this study was two-fold. The first aim was to determine if there were any anthropometric and physical performance differences (controlling for maturation) between male and female handball players selected in training categories as well asthe relation of these differences with the performance level achieved. The second aim was to identify the discriminatory variables between the performance levels achieved. A total of 216 young handball players (125 men and 91 women) participated in the study. The data were classified by selection level (regional n=154; national n=62), gender (men; women) and age category (under-15; under-17). The use of MANCOVA analyses, controllingfor maturation, identified how gender could determine variables related to handball players' future competitive levels. The results revealed that anthropometric variables such as height, arm span, trochanter height, thigh girth, and leg girth were more influential in men than in women. In addition, the physical performance tests of vertical jump (squat jump and counter movement jump with/without arm) and 10x5m shuttle run were determinants in both sexes. Discriminatory analysis predicted that a combination of five variables (counter movement jump with arm, body mass, 10x5m shuttle run, dominant hand length and trochanter height) would successfully distinguish between regional and national players, with a predictive accuracy of 81.9% for all players.

Efecto de la edad relativa en el atletismo español / Efeito da idade relativa no atletismo español / Relative age effect in Spanish athletics

La influencia del trimestre de nacimiento sobre el rendimiento de los atletas ha sido ampliamente estudiada, pero siempre en relación a un periodo temporal. La novedad de este trabajo es estudiar el efecto de la edad relativa en relación a los resultados deportivos. Para ello se analizó el efecto de la edad relativa (EER), denominado RAE en inglés, en los atletas españoles (3.313) que han conseguido las mejores marcas de todos los tiempos atletas desde 1940 hasta la actualidad. Se ha identificado la fecha de nacimiento de los atletas y se ha extraído el mes y el trimestre de nacimiento. La prueba de Chi-cuadrado (χ2 ) se ha utilizado para elaborar los resultados, que muestran que este efecto es consistente tanto en el atletismo masculino como en el femenino. En el atletismo masculino existe en todas las categorías de edad, mientras que en el atletismo femenino el efecto es mucho más débil, apareciendo sólo en la categoría absoluta y en la juvenil. En cuanto a los sectores de competición los resultados no muestran un patrón de comportamiento claro (AU)

A influência do trimestre de nascimento sobre o rendimento dos atletas é uma temática amplamente estudada, mas sempre em relação a um determinado período temporal. A novidade deste trabalho é o estudo do efeito da idade relativa em relação aos resultados desportivos. Assim, analisou-se o efeito da idade relativa (RAE) nos atletas espanhóis (3.313) que conseguiram as melhores marcas de todos os tempos desde 1940 até à atualidade. Utilizou-se o teste do Qui-quadrado para o tratamento dos dados, e os resultados, demonstram que este efeito é consistente tanto no atletismo masculino como no feminino. No atletismo masculino existe em todas as categorias de idade, enquanto no atletismo feminino o efeito é menos claro, aparecendo apenas na categoria absoluta e na juvenil. Relativamente aos setores de competição, os resultados não mostram um evidente padrão de comportamento (AU)

The influence of the trimester of birth on the athlete’s performance has been widely studied, but always related to a temporary term. What is new about this work is that the effect of relative age (RAE) related to sports results is studied. We focus on the effect of relative age on Spanish athletes (3.313) who have achieved the best records ever, what lets us analyse athletes since 1940. The Chi-square test (χ2 ) have been used for the compilation of results, which show that this effect is consistent both in male athletics and in female. In male athletics, it exists in every age category, while in female athletics; the effect is much weaker and only exists in absolute category and young category. With regard to competition sectors, results do not show a clear pattern of performance (AU)

Análisis de las conductas de los entrenadores después del tiro en baloncesto / Análise do comportamento dos treinadores no basquete após o disparo / Analysis of the behavior of coaches in basketball after shot

La presente investigación analiza las conductas de los entrenadores de baloncesto después del lanzamiento a canasta (tanto de los jugadores de su equipo como del equipo contrario) en situaciones de competición en categorías de formación. Intervinieron en el presente estudio tres entrenadores, todos poseen la titulación española oficial necesaria para entrenar en las diferentes categorías. Se han analizado 9 partidos oficiales de la Liga Gallega (3 por cada uno de los 3 entrenadores participantes) y se registraron 1196 conductas tras lanzamiento. El instrumento utilizado para la recogida de datos procede de una adaptación del Coach Behavioral Assessment System (Smith, Smoll y Hunt, 1977; Cruz, 1989) y del Sistema de Observación de las Conductas del Entrenador (Montero, 2004). Tras los resultados obtenidos, se puede afirmar que las conductas de inhibición ('ignorar el error' y 'no reforzar') son las más frecuentes y que el resultado en el marcador está asociado a cambios en el comportamiento de los entrenadores (AU)

O presente trabalho analisa o comportamento dos treinadores de basquete após arremesso à cesta (dos jogadores de sua equipe e da equipe adversária) em situações competitivas nas categorias de formação do basquetebol. São participantes deste estudo três treinadores, todos com as certificações necessárias para ser treinador em diferentes categorias na Espanha. Foram analisados nove jogos oficiais da Liga Gallega (três de cada um dos três treinadores participantes) e 1.196 observações foram feitas após arremessos. O instrumento utilizado para a coleta de dados foi adaptado do Coach Behavioral Assessment System (Smith, Smoll e Hunt, 1977; Cruz, 1989) e Sistema de Observación de las Conductas del Entrenador (Montero, 2004). Como resultados, observou-se que a conduta de inibição ('ignorar erro' e 'não reforçar') são os mais frequentes, e resultado no placar influencia o comportamento dos treinadores (AU)

The study presented below is an analysis of the behavior of basketball coaches after the shot (players of both teams) during the competition in youth categories. In this study, three coaches participed, everybody have the official Spanish qualifications needed to train in different categories. It was analyzed 9 official games of the Galician league (3 each of the 3 coaches participants) and 1196 behaviors were registered after shot. The instrument used for the data collection was an adaptation of the Coach Behavioral Assessment System (Smith, Smoll & Hunt, 1977) and of the Sistema de Observación de las Conductas del Entrenador (Montero, 2004). After the results obtained, we can say that the inhibition behaviors (ignore mistake and not reinforcement) are the most frequently and that the score is associated with changes in the behaviors of coaches (AU)

Efecto de la edad relativa en los mundiales de baloncesto FIBA en cateogrías inferiores (1979-2011) / Efeito da idade na no basquete FIBA mundo em baixa cateogrías (1979-2011) / Relative age effect in lower categories of FIBA basketball world championships (1979-2011)

El efecto de la edad relativa, en inglés, relative age effect (RAE) ha sido ampliamente estudiado en deporte, pero generalmente se centra en estudios realizados en un mismo año o en una misma temporada. El presente trabajo incluye una amplia muestra de Campeonatos del Mundo de Baloncesto FIBA que abarca desde 1979 hasta el 2011, analizando las fechas de nacimiento de 3699 jugadores de baloncesto (1975 hombres y 1724 mujeres) participantes en categorías U17, U19 y U21. Mediante la prueba de chi-cuadrado y utilizando como distribución de contraste la distribución de probabilidad uniforme corregida en función de los días de cada trimestre, se ha encontrado un efecto de la edad relativa en el baloncesto masculino y en el femenino y también agrupando ambos géneros de forma conjunta. Además el efecto de la edad relativa se presenta en todas las categorías de edad (U17, U19 y U21) tanto en el baloncesto masculino como en el femenino (excepto en U21 masculino), siendo en ambos casos más pronunciado en las competiciones en las que participan los deportistas más jóvenes (U17) y progresivamente menos acentuado hasta llegar a las competiciones donde los deportistas tienen más edad (U21) (AU)

O efeito da idade relativa, em inglês relative age effect (RAE), tem sido amplamente estudado no desporto, mas centra-se habitualmente em estudos realizados num mesmo ano ou numa mesma época desportiva. O presente estudo inclui uma ampla amostra de campeonatos do mundo de basquetebol FIBA desde o ano de 1979 até 2011, analisando as idades de nascimento de 3699 jogadores de basquetebol (1975 do sexo masculino e 1724 do sexo feminino) participantes em escalões Sub-17, Sub-19 e Sub- 21. Mediante a prova do qui-quadrado e utilizando como distribuição de contraste a distribuição de probabilidade uniforme corrigida em função dos dias de cada trimestre, encontrou-se um efeito de idade relativa no basquetebol masculino, no basquetebol feminino e também quando se agruparam ambos os géneros. Verifica-se ainda o efeito de idade relativa em todos os escalões etários (Sub-17, Sub-19 e Sub-21) tanto no basquetebol masculino, como no basquetebol feminino (exceto em Sub-21 masculino), sendo em ambos os casos mais evidente nas competições em que participam os desportistas mais jovens (Sub-17) e sendo progressivamente menos evidente até chegar às competições onde os desportistas têm idade mais elevada (Sub-21) (AU)

The relative age effect (RAE) has been widely studied in sports, however these studies are generally focused on the same academic year or sport season. A large sample of FIBA Basketball World Championship between 1979 and 2011 had been included in the current paper, analysing birth dates of 3699 basketball players (1975 men and 1724 women) participants in U17, U19 and U21 categories. Chi-square goodness-of-fit tests were used to compare the trimester of birth distribution (corrected based on the days of each trimester), it has been found a relative age effect in male and female basketball also gathering together both genders. In addition the relative age effect occurs in all age categories (U17, U19 and U21) in both men’s and women’s basketball (except males in U21), being more strong in both cases in the competitions in which younger athletes (U17) participate and progressively less pronounced up to competitions where athletes are older (U21) (AU)

Inconsistencies of the evaluation of home advantage in sports competitions under the three points per victory system.

A recent letter sent to the Journal of Human Kinetics' editor (Gómez & Pollard, 2014) warned about a supposed methodology error in the calculation of home advantage in football leagues used in Saavedra et al. (2013) and took the liberty of modifying the research's data. The aim of this letter is to demonstrate that the evaluation system of the home advantage proposed by Pollard (1986) contains serious inconsistencies when applied to competitions which give three points for a win and one point for a draw, as it is the case of the UEFA football leagues in the 21th century.