Differences in throwing capacity between senior and U-18 men handball players

The purpose of this investigation was to analyze the differences in general and specific throwing capacity of handball players as a function of the age category. Differences between throwing velocity to goal without and with opposition have also been addressed. Ninety four handball senior and U-18 players were assessed in four different situations of throwing: 1) heavy medicine ball throw, 2) light medicine ball throw, 3) throwing velocity without opposition and 4) throwing velocity with opposition. Senior players were found to perform far better than the U-18 players in all four throwing situations (p<0.001; t1=6.958; t2=8.244; t3=8.059; t4=5.399; df=92).Throwing velocity was higher without than with opposition for both groups; the throwing velocity of the senior group was 7.79% lower (p<0.01; t=8.317; df=47) when there was opposition, whereas U-18 players’ velocity lowered by 6.03% (p<0.01; t=4.469; df=45). The results suggest that age can be a determining factor in handball players’ throwing capacity, both general and specific. Likewise, the presence and interference of a goalkeeper appears to affect throwing velocity in a negative way, especially in senior player

New tool to assess the force production in the swallow

8 men artistic gymnasts were evaluated with a new test protocol in order to assess isometric strength in an specific hold position on still rings. The proposed test protocol measures the force applied the gymnast on the rings from an initial lying prone position on a force platform while he is trying to achieve the Swallow (or Hirondelle) position. The vertical force (FZ) from the forcetime curve registered (100 Hz) was used and it showed a descent from the initial body weight level caused by the gymnast force on the rings and, later, a maximal isometric force period. Fundamental and derivate variables to extract from the evolution of Fz were defined. Results showed significant statistical differences between gymnasts that could perform the Swallow (P) from those that could not (NP) (pmenor que0.05). Performer gymnasts were characterized by a higher percentage of body weight descent and higher strength in relation to body mass (pmenor que0.05). The practical application of this tool could be to provide coaches with information about how close the gymnast is to perform the Swallow

Oligomerization and Cell-Binding Properties of the Avian Reovirus Cell-Attachment Protein ςC

AbstractAvian reovirus protein ςC, the viral cell-attachment protein, is a minor component of the outer-capsid shell of the viral particle that is synthesized in small amounts in infected cells. We cloned the ςC-encoding ORF in vector pIL-2f, expressed it in Escherichia coli, and partially purified the resulting recombinant protein from inclusion bodies. Rabbit polyclonal antibodies raised against the recombinant protein specifically recognized the viral polypeptide in ELISA, immunoprecipitation, and Western blotting. To study the oligomerization capacity and cell-binding affinity of protein ςC, the ςC-encoding ORF was also expressed in chicken embryo fibroblasts (CEFs) and in reticulocyte lysates. In all three systems protein ςC is expressed as a multimer with identical electrophoretic mobility to the naturally occurring protein. Cell-binding experiments show that both in vitro and in vivo expressed protein ςC display affinity for CEF receptors, and this property is exclusively associated with the oligomeric form of the protein. The fact that incubation of CEF cells with the recombinant protein expressed in bacterial cells completely blocks the binding of purified reovirions indicates both that binding of this protein to cells is specific and saturable, and that reovirions and protein ςC bind to the same class of cell receptor. Saturation binding experiments, performed with the recombinant protein expressed in E. coli and with purified reovirions, showed that the number of cellular receptor sites (CRSs) for avian reovirus S1133 is 1.8 × 104 per CEF cell, whereas the number of cellular receptor units (CRUs) for ςC is 2.2 × 105 per CEF cell. These results are consistent with previous reports on the binding of mammalian reoviruses

Capacidad de lanzamiento en balonmano en función del puesto específico.

Se analizaron las diferencias en la capacidad de lanzamiento en función del puesto en jugadores de balonmano (n=48) de elite y amateurs con cuatro test: lanzamiento con balón medicinal pesado (LBP) y ligero (LBL), velocidad de lanzamiento sin (VLSO) y con oposición (VLCO). Los laterales lograron los mejores valores mientras los porteros obtuvieron los peores en los test más específicos, LBL (F 4,43=2,886; p<0,05), VLSO (F4,43=4,857; p<0,05) y VLCO (F4,43=12,828; p<0,01). El análisis de diferencias reveló que VLSO era mayor que VLCO (p<0,01) en todos los casos. Los resultados sugieren que el puesto es determinante en los lanzamientos específicos. Igualmente, la oposición influye significativamente disminuyendo la velocidad de lanzamiento en todos los casos

Differences and Relationship Between Standard and Specific Throwing Test in Handball According to the Competitive and Professional Level

The present study analyzed the differences in distance throwing with heavy and light medicine ball and throwing velocity between handball players of different competitive and professional level. Likewise, the relationship between the three throwing test of progressive specificity was analyzed: throwing with heavy medicinal ball (TH), throwing with light medicinal ball (TL) and throwing velocity (TV). For this purpose, sixty-five professional (P), semiprofessional (S) and non-professional (N) players were evaluated. El presente estudio analizó las diferencias en la distancia de lanzamiento realizado con balón medicinal pesado y ligero y en la velocidad de lanzamiento entre jugadores de balonmano de diferente nivel competitivo y profesional. Igualmente, la relación entre los tres test de lanzamiento, de progresiva especificidad, fue analizado: lanzamiento con balón medicinal pesado (TH), lanzamiento con balón medicinal ligero (TL) y velocidad de lanzamiento (TV). Para ello, sesenta y cinco jugadores profesionales (P), semi-profesionales (S) y no-profesionales (N) fueron evaluados

Field evaluation of a rapid diagnostic test (ParascreenTM) for malaria diagnosis in the Peruvian Amazon

BACKGROUND: The rapid diagnostic tests for malaria (RDT) constitute a fast and opportune alternative for non-complicated malaria diagnosis in areas where microscopy is not available. The objective of this study was to validate a RDT named Parascreen™ under field conditions in Iquitos, department of Loreto, Peru. Parascreen™ is a RDT that detects the histidine-rich protein 2 (HRP2) antigen from Plasmodium falciparum and lactate deshydrogenase from all Plasmodium species. METHODS: Parascreen™ was compared with microscopy performed by experts (EM) and polymerase chain reaction (PCR) using the following indicators: sensitivity (Se), specificity (Sp), positive (PV+) and negative predictive values (PV-), positive (LR+) and negative likehood ratio (LR-). RESULTS: 332 patients with suspected non-complicated malaria who attended to the MOH health centres were enrolled between October and December 2006. For P. falciparum malaria, Parascreen™ in comparison with EM, had Se: 53.5%, Sp: 98.7%, PV+: 66.7%, PV-: 97.8%, LR+: 42.27 and LR-: 0.47; and for non-P. falciparum malaria, Se: 77.1%, Sp: 97.6%, PV+: 91.4%, PV-: 92.7%, LR+: 32.0 and LR-: 0.22. The comparison of Parascreen™ with PCR showed, for P. falciparum malaria, Se: 81.8%, Sp: 99.1%, PV+: 75%, PV-: 99.4, LR+: 87.27 and LR-: 0.18; and for non-P. falciparum malaria Se: 76.1%, Sp: 99.2%, PV+: 97.1%, PV-: 92.0%, LR+: 92.51 and LR-: 0.24. CONCLUSIONS: The study results indicate that Parascreen™ is not a valid and acceptable test for malaria diagnosis under the field conditions found in the Peruvian Amazon. The relative proportion of Plasmodium species, in addition to the genetic characteristics of the parasites in the area, must be considered before applying any RDT, especially after the finding of P. falciparum malaria parasites lacking pfhrp2 gene in this region

¿Mejoran las TIC el proceso de enseñanza-aprendizaje deportivo del balonmano?

La motivación (M) y la capacidad de percepción-análisis (PA) del juego, variables del proceso de enseñanza-aprendizaje, fueron evaluadas tras utilizar diferentes recursos durante las explicaciones del entrenador. 71 jugadores (Sub-18) fueron divididos en dos grupos: G1 (n=35): recursos tradicionales; G2 (n=36): recursos multimedia. Se evaluó el nivel inicial (i) y final (f), tras 10 sesiones de entrenamiento. Ambas variables mejoraron significativamente en ambos grupos. Fueron mayores las mejoras del G2 en ambas variables (pmenor que.001). Se hallaron únicamente diferencias intergrupales en la evaluación final en M y PA (pmenor que.001), mostrando el Grupo 2 mejores resultados. Se concluye que la utilización de recursos multimedia posee un efecto positivo mayor que los recursos tradicionales sobre M y PA en jugadores de balonmano (Sub-18).[N1

Quantification of impacts in artistic gymnastics with accelerometry: an approximation

Intensity and volume of training in Artisti Gymnastics are increasing as the sooner athlete's age of incorporation creating some disturbance in them

The ballast pick-up problem. A theoretical approach and two experimental campaigns

The aim of this contribution is to present a theoretical approach and two experimental campaigns (on wind tunnel and on the track) concerning the research work about the ballast train-induced-wind erosion (BTIWE) phenomenon. When a high speed train overpasses the critical speed, it produces a wind speed close to the track large enough to start the motion of the ballast elements, eventually leading to the rolling of the stones (Kwon and Park, 2006) and, if these stones get enough energy, they can jump and then initiate a saltation-like chain reaction, as found in the saltation processes of soil eolian erosion (Bagnold, 1941). The expelled stones can reach a height which is larger than the lowest parts of the train, striking them (and the track surroundings) producing considerable damage that should be avoided. There is not much published work about this phenomenon, in spite of the great interest that exists due to its relevant applications in increasing the maximum operative train speed. Particularly, the initiation of flight of ballast due to the pass of a high speed train has been studied by Kwon and Park (2006) by performing field and wind tunnel experiments