1,194 research outputs found
The Association of Compact Groups of Galaxies with Large-scale Structures
We use various samples of compact groups (CGs) to examine the types of
association CGs have with rich and poor clusters of galaxies at low (z~0.04)
and intermediate (z~0.1) redshifts. We find that ~10-20 % of CGs are associated
with rich clusters and a much larger fraction with poorer clusters or loose
groups. Considering the incompleteness of catalogs of poorer systems at
intermediate redshift, our result is consistent with all CGs at intermediate
redshift being associated with larger-scale systems. The richness of the
clusters associated with CGs significantly increases from z~0.04 to z~0.1,
while their Bautz-Morgan type changes from early to late type for the same
range in z. Neither trend is compatible with a selection effect in the cluster
catalogs used. We find earlier morphological types of galaxies to be more
frequent in CGs associated with larger-scale structures, compared to those in
CGs not associated to such structures. We consider this as new evidence that
CGs are part of the large-scale structure formation process and that they may
play an important role in the evolution of galaxies in these structures.Comment: 5 pages, no figures, Proc. ESO Workshop "Groups of galaxies in the
nearby Universe", Santiago, Chile, 5-9 Dec. 2005, ESO Astrophysics Symposia,
eds. I. Saviane, V. Ivanov & J. Borissova, Springer-Verlag; very minor
revision of text on 15 Mar 2006, added one referenc
Politics Of Life Itself And The Future Of Medical Practices: Dialogues With Nikolas Rose (part 3)
216022123
Growth, functional capacities and motivation for achievement and competitiveness in youth basketball: An interdisciplinary approach
The interaction of multiple influences on the path to sport success is not yet fully understood by sport scientists. In this study, we examined variation in body size, functional capacities and motivation for achievement, competitiveness and deliberate practice of youth basketball players associated with differences in biological maturity status and chronological age. Reflecting the importance of interactive effects, we examined the relationships between the psychological variables and functional capacities. Fifty-eight male basketball players aged 9.5 to 15.5 years were considered. Variables included chronological age, estimated age at PHV, stature, body mass and sitting height by anthropometry; the Work and Family Orientation and Deliberate Practice Motivation Questionnaires were also used. Finally, the Line Drill test and Yo-Yo Intermittent Recovery level 1 (Yo-Yo IR1) tests were used as functional capacities indicators for basketball. Variance components models derived from series of multilevel linear regression models revealed a significant variation by maturity status for body size, functional capacities indicators, mastery and will to excel. The influence of estimated maturity status on mastery and will to excel was independent of chronological age. Furthermore, after controlling for age, an influence of estimated maturity on competitiveness was apparent. In contrast, no relationships were observed between psychological variables and functional capacities indicators. We conclude that growth-related changes are relevant to understanding players´ motivations for achievement, competitiveness and deliberate practice. This should be of interest to those involved in the selection and development of youth basketball players
Production of entanglement in Raman three-level systems using feedback
We examine the theoretical limits of the generation of entanglement in a
damped coupled ion-cavity system using jump-based feedback. Using Raman
transitions to produce entanglement between ground states reduces the necessary
feedback bandwidth, but does not improve the overall effect of the spontaneous
emission on the final entanglement. We find that the fidelity of the resulting
entanglement will be limited by the asymmetries produced by vibrations in the
trap, but that the concurrence remains above 0.88 for realistic ion trap sizes.Comment: 8 pages, 8 figure
Radiative decays of light vector mesons in a quark level linear sigma model
We calculate the P0 to gamma gamma, V0 to P0 gamma and V0to V'0 gamma gamma
decays in the framework of a U(3)xU(3) linear sigma model which includes
constituent quarks. For the first two decays this approach improves results
based on the anomalous Wess-Zumino term, with contributions due to SU(3)
symmetry breaking and vector mixing. The phi to (omega,rho) gamma gamma decays
are dominated by resonant eta' exchange . Our calculation for the later decays
improves and update similar calculations in the -closely related- framework of
vector meson dominance. We obtain BR(phi to rho gamma gamma)=2.5x10^{-5} and
BR(phi to omega gamma gamma)=2.8x10^{-6} within the scope of the
high-luminosity phi factories.Comment: 8 pages, submitted to Phys. Rev.
Variabilidade Do Desempenho No Line-drill Test Em Adolescentes Jogadores De Basquetebol
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)The practice of basketball during adolescence increases the body size and functional performance. Basketball involves short-time maximum effort for changes of direction, which use anaerobic metabolism and agility. Objective: To examine the variation in performance in the Line-drill Test in adolescent basketball players (n=59, age 9-15 years) in relation to the stage of somatic maturity (estimated age of peak growth velocity [PGV]) and the variation in body size. Methods: We considered chronological age, estimated time for the age of PGV by the maturity offset protocol, height and body mass measured by anthropometry, and performance in the Line Drill Test. Proportional allometric models were used to control the variation associated with the body size, chronological age, and maturity of inter-individual variation in the Line-drill Test. Results: We found a high negative linear relationship between performance in the Line-drill Test and chronological age (r=-0.64, 95% IC -0.77 - -0.46, p<0.01). The relationship between performance on the Line-drill Test and the time until the age of PGV proved to be non-linear, indicating slowdown in performance variation, approximately from the age of PGV and one year after the predicted PGV. The allometric models showed a negative relationship between body size and performance in the Line-drill Test. The amplitude of variance explained in the proportional allometric models ranged from 0.28 to 0.48. Negative exponents of small magnitude were observed for chronological age and the indicator of maturity being, however, significant and with reduced amplitude (-0.05 to -0.06) Conclusion: The use of allometric models to control the influence of body size can potentially help to understand the development of agility performances in adolescent basketball players. © 2016, Redprint Editora Ltda. All rights reserved.226445449PNPD/CAPES/2013, CAPES, Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorFAPESP, Fundação de Amparo à Pesquisa do Estado de São PauloCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP
Constraining the dark energy with galaxy clusters X-ray data
The equation of state characterizing the dark energy component is constrained
by combining Chandra observations of the X-ray luminosity of galaxy clusters
with independent measurements of the baryonic matter density and the latest
measurements of the Hubble parameter as given by the HST key project. By
assuming a spatially flat scenario driven by a "quintessence" component with an
equation of state we place the following limits on the
cosmological parameters and : (i) and (1) if the
equation of state of the dark energy is restricted to the interval (\emph{usual} quintessence) and (ii) and
() if violates the null energy condition and assume values (\emph{extended} quintessence or ``phantom'' energy). These results are in
good agreement with independent studies based on supernovae observations,
large-scale structure and the anisotropies of the cosmic background radiation.Comment: 6 pages, 4 figures, LaTe
Bianchi Type I Cosmology in Generalized Saez-Ballester Theory via Noether Gauge Symmetry
In this paper, we investigate the generalized Saez-Ballester scalar-tensor
theory of gravity via Noether gauge symmetry (NGS) in the background of Bianchi
type I cosmological spacetime. We start with the Lagrangian of our model and
calculate its gauge symmetries and corresponding invariant quantities. We
obtain the potential function for the scalar field in the exponential form. For
all the symmetries obtained, we determine the gauge functions corresponding to
each gauge symmmetry which include constant and dynamic gauge. We discuss
cosmological implications of our model and show that it is compatible with the
observational data.Comment: 13 pages, 2 figures, accepted for publication in 'European Physical
Journal C
Alternatives to Quintessence Model Building
We discuss the issue of toy model building for the dark energy component of
the universe. Specifically, we consider two generic toy models recently
proposed as alternatives to quintessence models, known as Cardassian expansion
and the Chaplygin gas. We show that the former is enteriely equivalent to a
class of quintessence models. We determine the observational constraints on the
latter, coming from recent supernovae results and from the shape of the matter
power spectrum. As expected, these restrict the model to a behaviour that
closely matches that of a standard cosmological constant .Comment: RevTex4; 7 pages, 4 figures. v2: Improved discussion of constraints
on Chaplygin gas models. Other clarifications added. Phys Rev. D (in press
Degeneration rate of preantral follicles in the ovaries of goats
The degeneration rate of ovarian preantral follicles in goats, and the distribution in the follicular classes (primordial, primary or secondary) was assessed. Ovaries from adult goats were collected at a local slaughterhouse. To evaluate the morphology of the caprine preantral follicles in situ, one fragment from each ovary was fixed individually in Carnoy for 12 h, sectioned serially at a thickness of 7 μm and stained with Periodic Acid Shiff-hematoxylin. Preantral follicles were then classified according to the stage of development. Preantral follicles were classified individually either as morphologically normal; as Type 1 degenerated follicles (only the oocyte was degenerated); or as Type 2 degenerated follicles (when degeneration occurred at both oocyte and granulosa cells). The total examined was 235 primordial, 195 primary and 101 secondary follicles. The distribution of degenerated follicles as primordial, primary and secondary follicles was 8.5, 14.3 and 16.8%, respectively. When Types 1 and 2 degenerated follicles were pooled, secondary follicles were significantly more degenerated than primordial and primary follicles. When degeneration Types 1 and 2 was compared in each follicular class, a higher (P<0.05) percentage of Type 1 degeneration was observed in primordial and primary follicles. Conversely, secondary follicles were significantly more affected by Type 2 degeneration. When the follicular classes were taken together, a significantly higher percentage of Type 1 degenerated preantral follicles was observed when compared with Type 2 degenerated follicles (P<0.05). In conclusion, a low percentage of degenerated preantral follicles was observed and secondary follicles were more affected by degeneration than primordial follicles. Thus, primordial follicles constitute a large and potentially valuable source of oocytes for reproductive programs after in vitro growth and maturation
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