Novel approaches for portfolio construction using second order stochastic dominance

In the last decade, a few models of portfolio construction have been proposed which apply Second Order Stochastic Dominance (SSD) as a choice criterion. SSD approach requires the use of a reference distribution which acts as a benchmark. The return distribution of the computed portfolio dominates the benchmark by the SSD criterion. The benchmark distribution naturally plays an important role since di erent benchmarks lead to very di erent portfolio solutions. In this paper we describe a novel concept of reshaping the benchmark distribution with a view to obtaining portfolio solutions which have enhanced return distributions. The return distribution of the constructed portfolio is considered enhanced if the left tail is improved, the downside risk is reduced and the standard deviation remains within a speci ed range. We extend this approach from long only to long-short strategies which are used by many hedge fund and quant fund practitioners. We present computational results which illustrate (i) how this approach leads to superior portfolio performance (ii) how signi cantly better performance is achieved for portfolios that include shorting of assets

Hydrodynamical analysis of single inclusive spectra and Bose-Einstein correlations for Pb+PbPb+Pb at 160 AGeV

We present the first analysis of preliminary data for $Pb+Pb$ at 160 $AGeV$ using 3+1-dimensional relativistic hydrodynamics. We find excellent agreement with the rapidity spectra of negative hadrons and the correlation measurements. The data indicates a large amount of stopping; $65\%$ of the invariant energy of the collision is thermalized and $73\%$ of the baryons are contained in the central fireball. Within our model this implies that a quark-gluon-plasma of lifetime 3.4 $fm/c$ was formed.Comment: 13 pages, 5 Postscript figures (attached to this file as compressed and uuencoded Postscript file

Soft Photons from Off-shell Particles in a Hot Plasma

Considering the propagation of off-shell particles in the framework of thermal field theory, we present the general formalism for the calculation of the production rate of soft photons and dileptons from a hot plasma. This approach is illustrated with an electrodynamic plasma. The photon production rate from strongly interacting quarks in the quark-gluon plasma, which might be formed in ultrarelativistic heavy ion collisions, is calculated in the previously unaccessible regime of photon energies of the order of the plasma temperature within an effective field theory incorporating dynamical chiral symmetry breaking.Comment: 8 pages in RevTeX format, 3 figures uuencoded postscript added. Also available by anonymous ftp at ftp://tpri6c.gsi.de/pub/phenning/qh95ga

Colonial values and asylum care in Brazil : reclaiming the streets through carnival in Rio de Janeiro

This chapter shows how carnival has been used to counter the impact of Brazil’s colonial history on its asylums and perceptions of madness. Colonisation of Brazil by Portugal in the nineteenth century led to a process of Europeanisation that was associated with dismissal of non-European customs and values as “mad” and sequestration of the poor from the streets into asylums. Bringing together the work of the two authors, the chapter describes through a case study how a carnival project, Loucura Suburbana (Suburban Madness), in which patients in both long- and short-term asylum care play leading roles, has enabled them to “reclaim the streets,” and re-establish their right to the city as valid producers of culture on their own terms. In the process, entrenched stigmas associated with having a history of mental illness in a local community are challenged, and sense of identity and self-confidence can be rebuilt, thus contributing to long-term improvements in mental well-being. Further illustrative materials are available including photographs and video clips

Direct Photon Production in Heavy Ion Reactions at SPS and RHIC

A review on experimental results for direct photon production in heavy ion reactions is given. A brief survey of early direct photon limits from SPS experiments is presented. The first measurement of direct photons in heavy ion reactions from the WA98 collaboration is discussed and compared to theoretical calculations. An outlook on the perspective of photon measurements at RHIC is given.Comment: 12 pages, 8 figures, invited talk at ICPA-QGP 2001, Jaipur, India, to be published in PRAMAN

Thermal Particle and Photon Production in Pb+Pb Collisions with Transverse Flow

Particle and photon production is analyzed in the presence of transverse flow using two approximations to describe the properties of the hadronic medium, one containing only $\pi, \rho, \omega$, and $\eta$ mesons (simplified equation of state) and the other containing hadrons and resonances from the particle data table. Both are considered with and without initial quark gluon plasma formation. In each case the initial temperature is fixed by requiring $dN_{ch}/dy \sim$ 550 in the final state. It is shown that most observables are very sensitive to the equation of state. This is particularly evident when comparing the results of the simplified equation of state in the scenarios with and without phase transition. The hadronic gas scenario leads to a substantially higher rate for the $p_T$-distribution of all particles. In the complete equation of state with several hundreds of hadronic resonances, the difference between the scenarios with and without phase transition is rather modest. Both photon and particle spectra, in a wide $p_T$ range, show very similar behavior. It is therefore concluded that from the $p_T$ spectra it will be hard to disentangle quark gluon plasma formation in the initial state. It is to be stressed however, that there are conceptual difficulties in applying a pure hadronic gas equation of state at SPS-energies. The phase transition scenario with a quark gluon plasma present in the initial state seems to be the more natural one.Comment: 9 pages RevTeX figures in postscript forma

Micronucleus formation induced by biomass burning particles derived from biomass burning induce high micronucleus frequency in Tradescantia pallida assay (TRAD-MN)

Manual harvesting is usually done after to sugar cane burning which is responsible for seasonal emission of air pollutants in Brazil and it is believed to be responsible for deleterious health effects in exposed populations. The mutagenic potential of sugar cane burning harvesting particulate and particle surrogates of residual oil fly ash (ROFA) were evaluated in assays measuring micronuclei (MN) in the pollen mother cells of Tradescantia pallida (TRAD-MN). Micronuclei frequencies in TRAD-MN to sugar cane burning residues (SCBR) at doses 0.3 and 0.03 mg/mL were respectively 2.18 ± 0.35 and 5.53 ± 1.04, whereas to ROFA from incinerator and ROFA from an electrostatic precipitator installed in one of the chimneys of a steel plant, MN frequencies were, respectively, 3.43 ± 0.7 and 4.90 ± 1.07. Significant differences were detected among the groups (p < 0.001), demonstrating that SCBR was at least as genotoxic as the fossil fuel derived particles. The results suggest that the burning process to harvest sugar cane should be better controlled. Keywords: pollution, burning particles, micronuclei, Tradescantia pallida . Partículas derivadas da queima de biomassa induzem alta frequência de micronúcleos no ensaio de Tradescantia pallida (TRAD-MN) Resumo A coleta de cana-de-açúcar manual é geralmente realizada após a queima, a qual é responsável pela emissão sazonal de poluentes atmosféricos no Brasil e acredita-se que este seja responsável pelos efeitos deletérios a saúde da população exposta. O potencial mutagênico da queima de cana-de-açúcar e partículas oriundas de resíduos em cinza de óleo queimado (ROFA) foi avaliado em ensaio que mede a freqüência de micronúcleos (MN) em células mãe de grão de pólen de Tradescantia pallida (TRAD-MN). A freqüência de TRAD-MN em resíduos de queima de cana de açúcar (SCBR) nas doses de 0.3 e 0,03mg/mL foi, respectivamente de 2,18 ± 0,35 e 5,53 ± 1,04, enquanto para ROFA de incinerador e ROFA de um precipitador eletrostático instalado em uma chaminé de uma indústria siderúrgica, a freqüência de MN foi, respectivamente, 3,43 ± 0,7 e 4,90 ± 1,07. Diferença significante foi observada entre os grupos (p<0,001), demonstrando que SCBR foi ao menos tão genotóxico quanto às partículas derivadas de combustíveis fósseis. Os resultados sugerem que o processo de queima de cana-de-açúcar no período da safra deveria ser mais bem controlado. Palavras-Chave: poluição, partículas de queimadas, micronúcleos, Tradescantia pallida

Transverse flow and hadro-chemistry in Au+Au collisions at \sqrt{s_{NN}}=200 GeV

We present a hydrodynamic assessment of preliminary particle spectra observed in Au+Au collisions at \sqrt{s_{NN}}=200 GeV. The hadronic part of the underlying equation of state is based on explicit conservation of (measured) particle ratios throughout the resonance gas stage after chemical freezeout by employing chemical potentials for stable mesons, nucleons and anti-nucleons. We find that under these conditions the data (in particular the proton spectra) favor a low freeze-out temperature of around 100 MeV. Furthermore we show that through inclusion of a moderate pre-hydrodynamic transverse flow field the shape of the spectra improves with respect to the data. The effect of the initial transverse boost on elliptic flow and the freeze-out geometry of the system is also elucidated.Comment: as published: more data included in Fig. 1, discussions throughout the text improved, 6 pages, 4 figure

Radiation of single photons from Pb+PbPb+Pb collisions at the CERN SPS and quark hadron phase transition

The production of single photons in $Pb+Pb$ collisions at the CERN SPS as measured by the WA98 experiment is analysed. A quark gluon plasma is assumed to be formed initially, which expands, cools, hadronizes, and undergoes freeze-out. A rich hadronic equation of state is used and the transverse expansion of the interacting system is taken into account. The recent estimates of photon production in quark-matter (at two loop level) along with the dominant reactions in the hadronic matter leading to photons are used. About 50% of the single photons are seen to have a thermal origin. An addition of the thermal and prompt photons is seen to provide a very good description of the data. Most of the thermal photons having large transverse momenta arise from the quark-matter, which contributes dominantly through the mechanism of annihilation of quarks with scattering, and which in turn is possible only in a hot and dense plasma of quarks and gluons. The results thus confirm the formation of quark gluon plasma and the existence of this mechanism of the production of single photons.Comment: 6 pages including 3 figures. Corrected 2-loop rates for photons are use