Hadronic centrality dependence in nuclear collisions

The kaon number density in nucleus+nucleus and p+p reactions is investigated for the first time as a function of the initial energy density $\epsilon$ and is found to exhibit a discontinuity around $\epsilon$=1.3 GeV/fm$^3$. This suggests a higher degree of chemical equilibrium for $\epsilon >$ 1.3 GeV/fm$^3$. It can also be interpreted as reflection of the same discontinuity, appearing in the chemical freeze out temperature (T) as a function of $\epsilon$. The $N^{\alpha \sim 1}$ dependence of (u,d,s) hadrons, whith N the number of participating nucleons, also indicates a high degree of chemical equilibrium and T saturation, reached at $\epsilon >$1.3 GeV/fm$^3$. Assuming that the intermediate mass region (IMR) dimuon enhancement seen by NA50 is due to open charm ($D \bar{D}$), the following observation can be made: a) Charm is not equilibrated. b) $J/\Psi/D \bar{D}$ suppression -unlike $J/\Psi/DY$- appears also in S+A collisions, above $\epsilon$ $\sim$1 GeV/fm$^3$. c) Both charm and strangeness show a discontinuity near the same $\epsilon$. d) $J/\Psi$ could be formed mainly through $c \bar{c}$ coalescence. e) The enhancement factors of hadrons with u,d,s,c quarks may be connected in a simple way to the mass gain of these particles if they are produced out of a quark gluon plasma (QGP). We discuss these results as possible evidence for the QCD phase transition occuring near $\epsilon \sim$1.3 GeV/fm$^3$.Comment: 4 pages, 4 figures, proceedings of Vth International Conference on Strangeness in Quark Matter, 20-25 July 2000, Berkeley, California. To appear in Journal of Physics G: Nuclear and Particle Physic

Les directives psychiatriques anticipées (DPA) et le rôle de l’autonomie

Bien que les directives psychiatriques anticipées (DPA) soient ancrées dans l’éthique de l’autonomie, le lien entre les deux reste imprécis. Les DPA sont des documents juridiques qui permettent aux personnes qui vivent avec un problème de santé mentale de spécifier leurs préférences de traitement advenant une incapacité future. Le rapport entre l’autonomie et les DPA a été abordé en termes tant légaux et éthiques que philosophiques, mais il n’a pas été clairement opérationnalisé sur le plan clinique. L’autonomie est une valeur éthique fondamentale qui englobe la notion d’indépendance face à des influences contrôlantes externes, ainsi que la capacité mentale de prendre ses propres décisions. Les personnes qui vivent avec un problème de santé mentale ont parfois besoin d’aide pour bien comprendre leurs droits éthiques et juridiques en matière de choix autonome, alors que les intervenants professionnels doivent être mieux formés quant à l’importance de l’autonomie dans leur pratique clinique. La capacité de consentir au traitement est le préalable d’ordre mental qui assure que les personnes ayant des troubles mentaux sont en mesure de rédiger des DPA en toute connaissance de cause, alors que l’autonomie est la valeur qui leur donne le pouvoir de contribuer à leur rétablissement.Although psychiatric advance directives (PADs) are grounded in the ethics of autonomy, the relationship between the two is unclear. PADs are legal documents that allow individuals with mental illness to record their treatment preferences should they become incompetent in the future. The relationship between autonomy and PADs has been discussed in ethical, legal, and philosophical terms, but has not been clearly operationalized for clinical purposes. Autonomy is a fundamental ethical value that includes having the independence from outside controlling influences and the mental capacity to direct one’s personal actions. Individuals with mental illness sometimes require assistance to understand their ethical and legal rights with respect to autonomous choice, and professional stakeholders need education regarding the importance of autonomy for clinical practice. Competency to consent to treatment is the mental prerequisite that ensures individuals with mental illness are able to complete PADs with insight, whereas autonomy is the value that empowers individuals to work towards their recovery.Aunque las directivas psiquiátricas anticipadas (DPA) se encuentran ancladas en la ética de la autonomía, la relación entre ambas es imprecisa. Las DPA son documentos jurídicos que permiten a las personas que viven con un problema de salud mental especificar sus preferencias de tratamiento en el caso de una incapacidad futura. La relación entre la autonomía y las DPA se aborda en términos tanto legales y éticos como filosóficos, pero no ha sido claramente puesta en operación en el plan clínico. La autonomía es un valor ético fundamental que engloba la noción de independencia frente a las influencias controladoras externas, así como la capacidad mental de tomar sus propias decisiones. Las personas que viven con un problema de salud mental en ocasiones necesitan ayuda para comprender sus derechos éticos y jurídicos en materia de elección autónoma, mientras que los interventores profesionales deben tener una mejor formación en cuanto a la importancia de la autonomía en la práctica clínica. La capacidad de consentir al tratamiento es la condición mental previa que asegura que las personas con trastornos mentales están en condiciones de redactar las DPA con todo conocimiento de causa. La autonomía les otorga el poder de contribuir a su restablecimiento.Apesar das Diretrizes Psiquiátricas Antecipadas (DPA) estarem enraizadas na ética da autonomia, o elo entre os dois ainda é vago. As DPA são documentos jurídicos que permitem às pessoas, que vivem com um problema de saúde mental, especificar suas preferências de tratamento no caso de uma inaptidão futura. A relação entre a autonomia e as DPA foi abordada em termos tanto legais e éticos quanto filosóficos, mas não foi claramente operacionalizada no plano clínico. A autonomia é um valor ético fundamental que engloba a noção de independência diante das influências controladoras externas, assim como a capacidade mental de tomar suas próprias decisões. As pessoas que vivem com um problema de saúde mental precisam, às vezes, de ajuda para compreender bem seus direitos éticos e jurídicos no que diz respeito à escolha autônoma, ao passo que os profissionais devem ser melhor formados quanto à importância da autonomia em sua prática clínica. A capacidade de consentir no tratamento é o requisito de ordem mental que garante que as pessoas que possuem transtornos mentais sejam capazes de redigir suas DPA em conhecimento de causa, já que a autonomia é o valor que lhes dá o poder de contribuir para seu próprio restabelecimento

Calculation Of Secondary Particles In Atmosphere And Hadronic Interactions

Calculation of secondary particles produced by the interaction of cosmic rays with the nuclei of Earth's atmosphere pose important requirements to particle production models. Here we summarize the important features of hadronic simulations, stressing the importance of the so called ``microscopic'' approach, making explicit reference to the case of the FLUKA code. Some benchmarks are also presented.Comment: 10 pages, 4 figures. Extended version of report given at the IInd Workshop on Matter and anti-Matter, Trento, Oct. 200

Strangeness production in heavy ion collisions at SPS and RHIC within two-source statistical model

The experimental data on hadron yields and ratios in central Pb+Pb and Au+Au collisions at SPS and RHIC energies, respectively, are analysed within a two-source statistical model of an ideal hadron gas. These two sources represent the expanding system of colliding heavy ions, where the hot central fireball is embedded in a larger but cooler fireball. The volume of the central source increases with rising bombarding energy. Results of the two-source model fit to RHIC experimental data at midrapidity coincide with the results of the one-source thermal model fit, indicating the formation of an extended fireball, which is three times larger than the corresponding core at SPS.Comment: Talk at "Strange Quarks in Matter" Conference (Strangeness'2001), September 2001, Frankfurt a.M., German

Fully Automatic and Real-Time Catheter Segmentation in X-Ray Fluoroscopy

Augmenting X-ray imaging with 3D roadmap to improve guidance is a common strategy. Such approaches benefit from automated analysis of the X-ray images, such as the automatic detection and tracking of instruments. In this paper, we propose a real-time method to segment the catheter and guidewire in 2D X-ray fluoroscopic sequences. The method is based on deep convolutional neural networks. The network takes as input the current image and the three previous ones, and segments the catheter and guidewire in the current image. Subsequently, a centerline model of the catheter is constructed from the segmented image. A small set of annotated data combined with data augmentation is used to train the network. We trained the method on images from 182 X-ray sequences from 23 different interventions. On a testing set with images of 55 X-ray sequences from 5 other interventions, a median centerline distance error of 0.2 mm and a median tip distance error of 0.9 mm was obtained. The segmentation of the instruments in 2D X-ray sequences is performed in a real-time fully-automatic manner.Comment: Accepted to MICCAI 201

A scalable data taking system at a test beam for LHC

We propose the installation of a data taking system at a test beam for the simultaneous test of LHC detectors, trigger and readout electronics, together with the development of the supporting architecture in a multiprocessor environment. A strong emphasis is put on a highly modular design, such that new hardware and software developments can be conveniently introduced for training and evaluation. One of the main thrusts of the project will be the modelling and system integration of different readout architectures, which are meant to provide a valuable training ground for new techniques. To address these aspects in a realistic manner, we propose to collaborate with two detector R+D projects

Antimatter and Matter Production in Heavy Ion Collisions at CERN (The NEWMASS Experiment NA52)

Besides the dedicated search for strangelets NA52 measures light (anti)particle and (anti)nuclei production over a wide range of rapidity. Compared to previous runs the statistics has been increased in the 1998 run by more than one order of magnitude for negatively charged objects at different spectrometer rigidities. Together with previous data taking at a rigidity of -20 GeV/c we obtained 10^6 antiprotons 10^3 antideuterons and two antihelium3 without centrality requirements. We measured nuclei and antinuclei (p,d,antiprotons, antideuterons) near midrapidity covering an impact parameter range of b=2-12 fm. Our results strongly indicate that nuclei and antinuclei are mainly produced via the coalescence mechanism. However the centrality dependence of the antibaryon to baryon ratios show that antibaryons are diminished due to annihilation and breakup reactions in the hadron dense environment. The volume of the particle source extracted from coalescence models agrees with results from pion interferometry for an expanding source. The chemical and thermal freeze-out of nuclei and antinuclei appear to coincide with each other and with the thermal freeze-out of hadrons.Comment: 12 pages, 8 figures, to appear in the proceedings of the conference on 'Fundamental Issues in Elementary Matter' Bad Honnef, Germany, Sept. 25-29, 200

The FLUKA atmospheric neutrino flux calculation

The 3-dimensional (3-D) calculation of the atmospheric neutrino flux by means of the FLUKA Monte Carlo model is here described in all details, starting from the latest data on primary cosmic ray spectra. The importance of a 3-D calculation and of its consequences have been already debated in a previous paper. Here instead the focus is on the absolute flux. We stress the relevant aspects of the hadronic interaction model of FLUKA in the atmospheric neutrino flux calculation. This model is constructed and maintained so to provide a high degree of accuracy in the description of particle production. The accuracy achieved in the comparison with data from accelerators and cross checked with data on particle production in atmosphere certifies the reliability of shower calculation in atmosphere. The results presented here can be already used for analysis by current experiments on atmospheric neutrinos. However they represent an intermediate step towards a final release, since this calculation does not yet include the bending of charged particles in atmosphere. On the other hand this last aspect, while requiring a considerable effort in a fully 3-D description of the Earth, if a high level of accuracy has to be maintained, does not affect in a significant way the analysis of atmospheric neutrino events.Comment: Papper has been corrected since the cosine of Zenith angle in flux tables was erraneously inverted. Also, fig. 17 and 18 have been correcte

Stable quark stars beyond neutran stars : can they account for the missing matter ?

The structure of a spherically symmetric stable dark 'star' is discussed, at zero temperature, containing 1) a core of quarks in the deconfined phase and antileptons 2) a shell of hadrons in particular $n$, $p$, $\Lambda$ and $\Sigma^-$ and leptons or antileptons and 3) a shell of hydrogen in the superfluid phase. If the superfluid hydrogen phase goes over into the electromagnetic plasma phase at densities well below one atom / $(10 fm)^{3}$, as is usually assumed, the hydrogen shell is insignificant for the mass and the radius of the 'star'. These quantities are then determined approximatively : mass = 1.8 solar masses and radius = 9.2 km. On the contrary if densities of the order of one atom / $(10 fm)^{3}$ do form a stable hydrogen superfluid phase, we find a large range of possible masses from 1.8 to 375 solar masses. The radii vary accordingly from 9 to 1200 km.Comment: 5 pages, 2 figures, contribution to Strange Quark Matter conference, Frankfurt, Germany, Sept. 200

Colonização micorrízica e crescimento da videira (Vitis vinifera, Porta-Enxerto P1103) em solo com alto teor de cobre.

A aplicação de fungicidas cúpricos em vinhedos aumenta o teor de Cu no solo, potencializando a toxidez para a videira. Entretanto, tem sido relatado que os fungos micorrízicos arbusculares (FMA) podem propiciar efeito protetor às plantas em solos contendo excesso de metais pesados. O trabalho objetivou avaliar a colonização micorrízica e o crescimento da videira (porta-enxerto P1103) em solo contendo elevados teores de Cu. Avaliou-se seis tratamentos de inoculação com FMA (Dentiscutata heterogama, Gigaspora gigantea, Acaulospora morrowiae, A. colombiana, Rhizophagus clarus e R. irregularis), além de um não inoculado. Verificou-se que a colonização micorrízica da videira foi elevada (média de 33%), mesmo em solo contendo excesso de Cu. A inoculação dos isolados de FMA testados pouco influenciou o crescimento da videira, mas a inoculação com R. irregulares e R. clarus beneficiou a produção de massa seca das raízes das mudas.Resumo expandido