Physics with Identified Particles at STAR

New physics results with identified particles at STAR are presented. Measurements at low $p_T$ address bulk properties of the collision, while those at high $p_T$ address jet energy loss in the bulk matter produced. Between these extremes, measurements at intermediate $p_T$ address the interplay between jets and the bulk. We highlight: measurements of $v_2$ fluctuations as a new, sensitive probe of the initial conditions and the equation of state; correlations involving multi-strange particles, along with ratios of identified particles to test coalescence as a mechanism of particle production at intermediate $p_T$; three particle azimuthal correlation to search for conical emission; and the energy and particle-type dependence of hadron production at high $p_T$ to study quark and gluon jet energy loss.Comment: 9 pages, 7 figures. To appear in the proceedings of the 19th International Conference on Ultra-Relativistic Nucleus-Nucleus Collisions (Quark Matter 2006), Shanghai, China, November 14-20, 200

π,K,p\pi, K, p and pˉ\bar{p} production from Au+Au collisions at sNN=62.4\sqrt{s_{_{NN}}} = 62.4 GeV

The preliminary results of $\pi^{\pm}, K^{\pm}, p$ and $\bar{p}$ spectra are reported from Au+Au collisions at $\sqrt{s_{_{NN}}} = 62.4$ GeV. Particle identification is from the Time Projection Chamber and Time-of-Flight system at STAR. The nuclear modification factor $R_{CP}$ for mesons ($\pi^{\pm}, K^{\pm}$) and baryons ($p, \bar{p}$) will also be discussed.Comment: 5 pages, 4 figures, Contributed to 8th International Conference on Strangeness in Quark Matter (SQM 2004),to be published in Journal of Physics

Everything is at stake; yet nothing is at stake : exploring meaning-making in game-centred approaches

While not wishing to cover old ground in articulating the promise or continued promise of phenomenology within the physical education and sports domains, this paper aims to explore the ‘human’ nature of the game-centred approach (GCA) from an existential-phenomenological perspective. In a recent review of literature on the current state of research on GCAs, Harvey and Jarrett made the call for phenomenological-oriented empirical studies. Urging the academic fraternity to embrace such ‘participatory epistemologies’ is an extremely positive and important step by the authors. This is because, although they do not explicitly make the point, to call for the embrace of phenomenological-oriented research into GCAs, the authors are accepting the fundamental importance of individual experience and meaning in games teaching. If we focus on the individual it then becomes a distinct possibility of structuring increasingly meaningful game-centred practice. In this respect we analyze Martin Heidegger's notion of ‘being-in-the-world’ and illustrate how Arnold's three categories of meaningful movement—primordial, contextual and existential—can help facilitate ideas for pedagogical practice and provide an appropriate interpretive lens for future research into GCAs

Kako budući stručnjaci u sportu, tjelovježbi i tjelesnome odgoju percipiraju tjelesni izgled pretile djece

Anti-fat bias has been previously identified amongst practising obesity health care specialists, physical education (PE) teachers and students of exercise science and PE in samples in the USA and New Zealand. The present research investigated the perceptions of the physical self of ‘fat’ versus ‘normal-weight’ children held by 167 students studying sport exercise and PE related programmes in higher education in England. Onesample t-tests identified that the sample held negative perceptions towards ‘fat’ children (identified by subscale mean scores that were significantly different from the subscale mean of 2.5 that would identify equivocal perception between ‘fat’ and ‘normal-weight’ children) on five of the six subscales of an adapted version of the Children & Youth Physical Self Perception Profile (CONDITION 1.52±.49; BODY 1.63±.43; PHYSICAL SELF-WORTH 1.79±.47; SPORT 1.88±.45; GLOBAL SELF-ESTEEM 2.10±.50, all p<.01; STRENGTH 2.48±.52, p=.67). Such results are indicative of the obesity discourse that currently prevails within PE and sport professions; a discourse constructed, arguably, on misleading foundations. Obesity awareness training is, therefore, required in such trainee exercise science, sport and PE populations. Pedagogical approaches espoused during programmes of study ought to emphasize personal meaning, personal reference and childcenteredness so that such approaches are more likely to be employed in their future professional practice.Predrasude prema pretilim ljudima utvrđene su kod specijalista zdravstvene skrbi koji se bave pretilošću, kod profesora tjelesne i zdravstvene kulture te studenata kineziologije u SAD-u i Novom Zelandu. Cilj provedenog istraživanja bio je utvrditi percepcije tjelesnog izgleda “debele” u odnosu na djecu “normalne težine” kod 167 studenata kineziologije (sporta, vježbanja i fizičke kulture) u Engleskoj. Rezultati t-testova su pokazali da su ispitanici imali negativnu percepciju pretile djece (utvrđeno srednjim vrijednostima podljestvice koje su se statistički značajno razlikovale od njezine aritmetičke sredine (2,5) koja bi potvrdila jednaku percepciju pretile djece i djece normalne težine), na pet od ukupno šest podljestvica adaptirane verzije upitnika Children & Youth Physical Self Perception Profile (kondicijska pripremljenost 1.52±.49; slika tijela 1.63±.43; tjelesno samovrednovanje 1.79±.47; sportska kompetencija 1.88±.45; opće samopouzdanje 2.10±.50, svi na razini značajnosti p<.01; te tjelesna jakost i snaga 2.48±.52, p=.67). Dobiveni rezultati su indikativni za odnos prema pretilim osobama koji trenutno prevladava kod profesionalnih djelatnika u sportu i tjelesnoj i zdravstvenoj kulturi, a koji je nedvojbeno izgrađen na pogrešnim temeljima. Stoga je za populacije pripravnika u kineziologiji, sportu i tjelesnoj i zdravstvenoj kulturi potrebna edukacija i razvoj svijesti o pretilosti. Pedagoški pristupi koji se provode u okviru studijskih programa trebali bi naglasiti osobnost pojedinca, te osobni odnos i orijentaciju prema djetetu kako bi takvi pristupi i takav odnos prema djeci bili i primijenjeni u budućem profesionalnom radu sportskih stručnjaka i znanstvenika

Characterization of dendritic morphology and neurotransmitter phenotype of thoracic descending propriospinal neurons after complete spinal cord transection and GDNF treatment

After spinal cord injury (SCI), poor regeneration of damaged axons of the central nervous system (CNS) causes limited functional recovery. This limited spontaneous functional recovery has been attributed, to a large extent, to the plasticity of propriospinal neurons, especially the descending propriospinal neurons (dPSNs). Compared with the supraspinal counterparts, dPSNs have displayed significantly greater regenerative capacity, which can be further enhanced by glial cell line-derived neurotrophic factor (GDNF). In the present study, we applied a G-mutated rabies virus (G-Rabies) co-expressing green fluorescence protein (GFP) to reveal Golgi-like dendritic morphology of dPSNs. We also investigated the neurotransmitters expressed by dPSNs after labeling with a retrograde tracer Fluoro-Gold (FG). dPSNs were examined in animals with sham injuries or complete spinal transections with or without GDNF treatment. Bilateral injections of G-Rabies and FG were made into the 2nd lumbar (L2) spinal cord at 3 days prior to a spinal cord transection performed at the 11th thoracic level (T11). The lesion gap was filled with Gelfoam containing either saline or GDNF in the injury groups. Four days post-injury, the rats were sacrificed for analysis. For those animals receiving G-rabies injection, the GFP signal in the T7-9 spinal cord was visualized via 2-photon microscopy. Dendritic morphology from stack images was traced and analyzed using a Neurolucida software. We found that dPSNs in sham injured animals had a predominantly dorsal-ventral distribution of dendrites. Transection injury resulted in alterations in the dendritic distribution with dorsal-ventral retraction and lateral-medial extension. Treatment with GDNF significantly increased the terminal dendritic length of dPSNs. The density of spine-like structures was increased after injury, and treatment with GDNF enhanced this effect. For the group receiving FG injections, immunohistochemistry for glutamate, choline acetyltransferase (ChAT), glycine, and GABA was performed in the T7-9 spinal cord. We show that the majority of FG retrogradely-labeled dPSNs were located in the Rexed Lamina VII. Over 90% of FG-labeled neurons were glutamatergic, with the other three neurotransmitters contributing less than 10% of the total. To our knowledge this is the first report describing the morphologic characteristics of dPSNs and their neurotransmitter expressions, as well as the dendritic response of dPSNs after transection injury and GDNF treatment

Electrically active defects in boron doped diamond homoepitaxial layers studied from deep level transient spectroscopies and other techniques

International audienceHomoepitaxial thin films of boron doped diamond are investigated with the help of Fourier transform deep level transient spectroscopy (FT-DLTS) and high resolution isothermal transient spectroscopy (HR-ITS) in order to determine the properties of hole traps. Conductivity studies and other characterisation techniques of defects are also used to bring complementary information. The main conclusions are as follows: (i) many hole traps can be found with activation energies in the range 0.9-1.6 eV; (ii) most of them showinwards decreasing concentrations, which passes below 10^15/cm3 at a depth close to a few hundred nanometers from the surface; (iii) some of them are metastable, in the sense the emission rate distribution undergoes changes after thermal treatments performed at temperatures well belowthose used for growth and previous annealing. These two last facts suggest that hydrogen atoms may be involved in charged defects. In other samples, an irreversible decrease of the conductivity correlated with the increase of the cathodoluminescence (CL)Aband demonstrates that a deep donor is connected with dislocations and acts as a very efficient compensating centre in the first 400 nm just below the surface but with a decreasing concentration deeper inside the homoepitaxial layer. The physical origin of these deep levels is discussed and believed to be likely connected with hydrogen atoms

Green infrastructure sustains the food-energy-water-habitat nexus

The ecosystem service potential of urban green infrastructure (GI) is increasingly appreciated, yet its underpinning role in the food-energy-water-habitat (FEWH) nexus is unclear. In order to explore the positive and negative impacts of GI on the FEWH nexus, this study asked three questions: 1) What are the research hotspots in FEWH for GI and what are the trends over time? 2) What ecosystem services can GI provide in terms of FEWH? 3) Can we quantify the ecosystem service potential of GI, and what are the synergies and trade-offs among the service types? By collating the research evidence which supports the ecosystem service potential of GI to contribute to FEWH, we developed a matrix to score the potential and to assess the synergies and trade-offs among ecosystem services. From this, a conceptual framework of the role of GI in supporting the FEWH nexus was developed. The results show that the potential of GI to sustain the FEWH nexus is significant and that multi-functional GI planning is necessary to minimize the trade-offs between them. This requires the application of new methods, theories, adaptation to new circumstances, and the development of appropriate business models within the planning domain, as well as compliance with policy directions and funding externally

Classification of minimal actions of a compact Kac algebra with amenable dual

We show the uniqueness of minimal actions of a compact Kac algebra with amenable dual on the AFD factor of type II$_1$. This particularly implies the uniqueness of minimal actions of a compact group. Our main tools are a Rohlin type theorem, the 2-cohomology vanishing theorem, and the Evans-Kishimoto type intertwining argument.Comment: 68 pages, Introduction rewritten; minor correction

Effects of rapid prey evolution on predator-prey cycles

We study the qualitative properties of population cycles in a predator-prey system where genetic variability allows contemporary rapid evolution of the prey. Previous numerical studies have found that prey evolution in response to changing predation risk can have major quantitative and qualitative effects on predator-prey cycles, including: (i) large increases in cycle period, (ii) changes in phase relations (so that predator and prey are cycling exactly out of phase, rather than the classical quarter-period phase lag), and (iii) "cryptic" cycles in which total prey density remains nearly constant while predator density and prey traits cycle. Here we focus on a chemostat model motivated by our experimental system [Fussmann et al. 2000,Yoshida et al. 2003] with algae (prey) and rotifers (predators), in which the prey exhibit rapid evolution in their level of defense against predation. We show that the effects of rapid prey evolution are robust and general, and furthermore that they occur in a specific but biologically relevant region of parameter space: when traits that greatly reduce predation risk are relatively cheap (in terms of reductions in other fitness components), when there is coexistence between the two prey types and the predator, and when the interaction between predators and undefended prey alone would produce cycles. Because defense has been shown to be inexpensive, even cost-free, in a number of systems [Andersson and Levin 1999, Gagneux et al. 2006,Yoshida et al. 2004], our discoveries may well be reproduced in other model systems, and in nature. Finally, some of our key results are extended to a general model in which functional forms for the predation rate and prey birth rate are not specified.Comment: 35 pages, 8 figure

Time-delayed model of immune response in plants

In the studies of plant infections, the plant immune response is known to play an essential role. In this paper we derive and analyse a new mathematical model of plant immune response with particular account for post-transcriptional gene silencing (PTGS). Besides biologically accurate representation of the PTGS dynamics, the model explicitly includes two time delays to represent the maturation time of the growing plant tissue and the non-instantaneous nature of the PTGS. Through analytical and numerical analysis of stability of the steady states of the model we identify parameter regions associated with recovery and resistant phenotypes, as well as possible chronic infections. Dynamics of the system in these regimes is illustrated by numerical simulations of the model