Number Of Rebounds Research Articles

Performance differences between winning and losing basketball teams during close, balanced and unbalanced quarters

Previous studies in basketball performance have tended to assess differences between winners and losers of games. This methodology does not consider the fluctuating nature of scoring within games. Consequently winning and losing performance for each quarter of 26 games of the Hungarian basketball league in 2007/08 were compared with the difference in points scored used as an independent variable with three levels (identified through cluster analysis as close (1 to 5 points), balanced (6 to 11 points) and unbalanced periods (12 to 22 points)). Wilcoxon signed ranks tests identified significant differences between winning and losing quarter performance for 20 performance indicators when all quarters were analysed (n = 100) in comparison to just 5 for close quarters only (n = 42). The five performance indicators (number of successful free throws, number of defensive rebounds, total amount of rebounds and rebounding percentage in offence and defence) suggest that mainly the success in rebounding might be the critical factor that determines winning and losing in these close situations. Kruskal Wallis H tests and Mann Whitney U post-hoc tests revealed differences between winning performances from close, balanced and unbalanced quarters for the 3 point performance (number of successful 3 point shots, number of 3 point attempts and 3 point shooting performance), the number of assist passes and turnovers; these findings could be explained by the significantly different features of defensive resistance during different types of periods.

Parâmetros antropométricos e indicadores de desempenho em atletas da seleção brasileira feminina de basquetebol

The aim of the present study was to investigate the correlation between anthropometric parameters (weight, height, body fat, BMI) and performance indicators (playing time, points, rebounds, errors, steals) in female national basketball players. The study was conducted during the 2000 and 2004 Olympic Games. Data were analyzed by ANOVA with random effects. Pearson’s simple correlation coefficients were also determined. No difference in anthropometric profile or performance indicators was observed between the two national teams (2000 and 2004). There was a significant correlation (r = 0.61, p<0.05) between height and number of rebounds. Free fat mass was also correlated with the number of rebounds performed (r = 0.45, p<0.05). BMI showed moderate correlations with playing time (r = -0.51, p<0.05), points scored (r = -0.50, p<0.05), number of errors (r = 0.53, p<0.05), and number of steals (r = -0.43, p<0.05). A similar pattern of correlation was observed between relative fat mass (%) and performance indicators (playing time: -0.51, points scored: -0.44, errors: 0.50, and steals: 0.51) (p<0.05). The present results indicate a relationship between anthropometric profile and performance indicators. The results also suggest that height and free fat mass influence rebound performance. In addition, it is reasonable to assume that body fat interferes with most of the performance indicators analyzed.

Monitoramento da carga interna no basquetebol.

The aim of this study was to quantify the magnitude of the internal load induced by an official women’s basketball match and to determine whether the magnitude of the internal load is correlated with the number of basketball maneuvers perfomed. The sample consisted of 10 athletes (25 ± 4 years), who participated in the XI Brazilian Women’s Basketball Championship. Heart rate and rating of perceived exertion in response to the match were evaluated. The internal load was calculated by the methods of Edwards and Foster. In addition, the basketball maneuvers perfomed in the match were analyzed. The internal load estimated by the methods of Edwards and Foster was 255 ± 62 and 321 ± 127 arbitrary units, respectively. A moderate correlation was observed between the two methods used (r = 0.64, p <0.05). In addition, significant correlations (p <0.05) were observed between internal load estimated by the method of Edwards and the number of points scored in the match (r = 0.53), number of rebounds (r = 0.67), number of assists (r = 0.59), number of steals (r = 0.70), and the sum of all indicators (r = 0.64). The results of this study suggest that the internal load of the match was moderate and was influenced by the number of maneuvers performed by the athletes in the match.

Performance indicators that distinguish winning and losing teams in basketball

To prepare a team for basketball games, to build up the best tactics, to make good decisions during a game, coaches need to know which elements of matches are the most crucial ones. Especially at close games where there is small difference between the performances of two teams. The main purpose of this study was to identify those critical performance indicators that most distinguish between winning and losing performances within matches. The statistical analysis of basketball games can lead to the identification of many significant performance indicators, not all of which can be analysed in real time. Therefore, a smaller subset of critical performance indicators can be identified by analysing close matches only. Data from 54 matches were gathered from the official score sheets of the European Basketball Championship 2007. Cluster analysis was used to classify the matches into three types such as tight games, balanced games and unbalanced games. There were 28 of these matches that were close matches where the differences between the two teams were 9 points or less. Wilcoxon signed ranks tests were used to compare 18 performance indicators between the winning and losing teams within each type of match. There were 13 significant performance indicators for the full set of matches. This was reduced to 6 critical performance indicators when only the close matches were considered. The analysis of tight matches explored that the winning teams had significantly less 3 point attempts (p<0.05) with higher shooting percentage (p<0.01). The number of successful free throws (p<0.01), the free throw percentage (p<0.001) and the number of defensive rebounds (p<0.01) also contributed to achieve a higher number of scored points and consequently determined success.

Dynamic Rebound Behavior of Silica/Natural Rubber Composites: Fly Ash Particles and Precipitated Silica

This article investigated the elastic response of natural rubber (NR) compounds filled with silica from fly ash particles (FASi) and commercial precipitated silica (PSi), through a dynamic rebound test. The effects of silica content and initial drop‐height on the height and number of rebounds, dynamic stiffness, and the energy loss were of interest. The results suggested that the unfilled NR vulcanizates exhibited a greater elastic response than the FASi and PSi‐filled vulcanized composites. For given silica contents, the NR compounds with FASi had better elastic response than those with PSi, where the elastic response decreased with an increase in silica content. The greater the silica contents, the higher the dynamic stiffness of the composites. The initial drop‐height had no effects on the elastic response change for the unfilled NR compound, but resulted in an increase in the energy loss for the silica‐filled NR composites. The differences in the elastic responses for the NR compounds filled with silica from FASi and PSi were associated with the differences in crosslink density and the filler–filler interaction influenced by content of bis(3‐triethoxysilylpropyl) tetrasulfane (designated as Si69) used.

Model and experiments of a drop impinging on an immersed wall

We present a model describing the rebound of a drop impinging on a rigid plane wall immersed in water. This model is based on the resolution of the drop equation of motion in an unbounded fluid in which an additional pressure force is introduced accounting for the wall effect on the drop motion. This force is computed from a film drainage simulation model during the approach of the deformable particle to the wall. Results of the model have been compared with experimental trajectories of drops impinging vertically at terminal rise velocity against a horizontal wall immersed in water at rest. These trajectories have been obtained with the help of an image processing technique. A wide range of experimental conditions has been studied (drop diameter, interfacial tension, drop viscosity, and density). In most of the cases, the model predicts the experimental trajectories within a very good accuracy (height of bouncing, deformation, number of rebounds) even in the case of a significant deformation. The numerical results show that the rebound of a deformable inclusion against a wall in water is essentially governed by the balance between the added mass force and the film pressure force exerted on the drop during the impact. The model has also been successfully tested in the case of an impinging bubble at high particle Reynolds number, based on experimental data taken from Tsao and Koch [Phys. Fluids 9, 44 (1997)].

Étude des poussées cliniques évolutives et des rebonds sérologiques d'enfants atteints de toxoplasmose congénitale et suivis durant les 2 premières années de vie

Background. - The survival of T gondii bradyzoites in cysts explains clinical reccurrences and serological rebounds after birth in children with congenital toxoplasmosis. At the present time, management of such manifestations is not well defined. Patients and methods. - Sixty-three infants with congenital toxoplasmosis were followed-up at the University Hospital of Lille (France) during the first two years of life. For each child, the treatment before and after birth was well defined. Clinical, opthalmological, radiological and serological data were collected every third month. Serological assays specially adapted to this age bracket were used for the quantification of specific IgG, or for the detection of T gondii specific IgM and IgA. Results. - Seventy-six serological rebounds were reported in 55 of the 63 children (87%). They concerned essentially IgG (96%) and IgA frequently IgM (47%) or IgA (60%). At the same time, only five clinical reccurrences were observed, four of them being preceded by a serological rebound. Discussion. - Treatment of fetuses of children with pyrimethamine and sulfonamides versus spiramycin alone was associated with a decrease in the frequency of serological rebounds during the first year of life ( P < 0.001). Such a therapeutic regimen during the second year of life decreases the appearance of serological rebounds in children without rebound antecedent ( P < 0.001). Conclusion. - The increase in number of rebounds after the end of a course of pyrimethamine and sulfonamides necessitates the evaluation of such a long term treatment without interruption.

Sonoluminescence and bubble dynamics for a single, stable, cavitation bubble

High-amplitude radial pulsations of a single gas bubble in several glycerine and water mixtures have been observed in an acoustic stationary wave system at acoustic pressure amplitudes on the order of 150 kPa (1.5 atm) at 21–25 kHz. Sonoluminescence (SL), a phenomenon generally attributed to the high temperatures generated during the collapse of cavitation bubbles, was observed as short light pulses occurring once every acoustic period. These emissions can be seen to originate at the geometric center of the bubble when observed through a microscope. It was observed that the light emissions occurred simultaneously with the bubble collapse. Using a laser scattering technique, experimental radius-time curves have been obtained which confirm the absence of surface waves, which are expected at pressure amplitudes above 100 kPa. [S. Horsburgh, Ph.D. dissertation, University of Mississippi (1990)]. Also from these radius-time curves, measurements of the pulsation amplitude, the timing of the major bubble collapse, and the number of rebounds were made and compared with several theories. The implications of this research on the current understanding of cavitation related phenomena such as rectified diffusion, surface wave excitation, and sonoluminescence are discussed.

A BALLISTOMETER FOR THE STUDY OF THE PLASTO-ELASTIC PROPERTIES OF SKIN

The ballistrometer is based on the "drop impact" of a body onto a stationary surface. A collision in one dimension is provoked by allowing a hard body to drop from a given height onto the skin surface to be tested. After the collision, the impacting body undergoes a variable number of rebounds decreasing in amplitude. By measuring the height of the rebounds, the amount of energy returned by the tissue is calculated in terms of coefficient of restitution e. The equipment, consisting of a hammer unit, a feeder-amplifier, and a plotter, is described. Ballistometry has been carried out on skin areas of 46 normal subjects ranging in age from 8 to 80 years, as well as on pathologic and cadaveric skin. The results show a progressive decrease of e with advancing age, as well as differences related to various skin regions. The tests performed on pathologic skin showed a lowered e in epidermal hyperplasia, hyperkeratosis, sclerosis, and dermal infiltration. An increase of e was observed when a high water content was present in the skin.

Selection rules for classical reactive trajectories: Dynamical allowedness and forbiddenness

A simple model for a particle climbing an inclined plane limited by rigid walls, towards an exit symbolizing the entrance of a product valley, demonstrates the general existence of reactive and unreactive bands. The system can be described by a single parameter η. The dynamically “allowed” or “forbidden” outcome of the reaction is shown to depend on the dynamical number N which characterizes the number of rebounds of the particle on the rigid walls. For given total energy, each value of N defines a reactive band which is accessible only for certain intervals of the initial energy in the direction perpendicular to the reaction coordinate. Depending on the value of the parameter η, the onset energy for reactive bands can vary either quadratically with N or linearly with N.

ICE NUCLEATION AND PROPAGATION IN SPRUCE NEEDLES

Needles of Colorado blue spruce, Picea pungens Engelm., have a freezing curve with a single rebound when their water supply is adequate and a double rebound when it is deficient. Nucleation takes place in the stele, probably in the xylem, in all needles, whether fresh, watered, or dried, and regardless of season. When two rebounds occur the first is always small, representing freezing of a small mass of water, restricted to the stele; the second is much larger and represents freezing of the bulky mesophyll, predominantly. The second rebound is caused by impeded propagation of ice and not by a second nucleation.The barrier impeding ice propagation and giving rise to two separate rebounds is considered to be the endodermis, which acts as a moisture valve or regulator. When water supply is insufficient the endodermis stops transferring water, becomes somewhat dehydrated, and no longer permits the rapid ice penetration that results in a single rebound. However, endodermal dehydration is only partial; ice growth is slow, but when penetration is effected, the mesophyll freezes.The presence or absence of a moisture film lining the intercellular spaces of the mesophyll does not directly affect the number of rebounds. When a film is present, extracellular freezing of the mesophyll is likely; when absent, freezing of the mesophyll is intracellular, more specifically intrawall, with ice accreting interiorly on the wall. Condensation of a freezable film is shown to be impossible. A descriptive terminology relating ice location to details of cell structure is desirable.Since spruce needles supercool only to about −10 °C, they freeze and thaw frequently during the winter in southern Canada, normally without injury.