Resonances and fluctuations of strange particle in 200 GeV Au-Au collisions

We perform an analysis of preliminary data on strange particles yields and fluctuations within the Statistical hadronization model. We begin by describing the theoretical disagreements between different statistical models currently on the market. We then show how the simultaneous analysis of yields and fluctuations can be used to differentiate between the different models, and determine if one of them can be connected to underlying physics. We perform a study on a RHIC 200 GeV data sample that includes stable particles, resonances, and the event-by-event fluctuation of the $K/\pi$ ratio. We show that the equilibrium statistical model can not describe the fluctuation, unless an unrealistically small volume is assumed. Such small volume then makes it impossible to describe the total particle multiplicity. The non-equilibrium model,on the other hand, describes both the $K/\pi$ fluctuation and yields acceptably due to the extra boost to the $\pi$ fluctuation provided by the high pion chemical potential. $\Lambda(1520)$ and $K^*$ abundance is described within error bars, but the $\Sigma^*$ is under-predicted to $\sim$ 1.5 standard deviations. We suggest further measurements that have the potential to test the non-equilibrium model, as well as gauge the effect of re-interactions between hadronization and freeze-out.Comment: References added, equations corrected. As accepted for publication by Journal of Physics

Particle yield fluctuations and chemical non-equilibrium at RHIC

We study charge fluctuations within the statistical hadronization model. Considering both the particle yield ratios and the charge fluctuations we show that it is possible to differentiate between chemical equilibrium and non-equilibrium freeze-out conditions. As an example of the procedure we show quantitatively how the relative yield ratio $\Lambda/K^-$ together with the normalized net charge fluctuation v(Q)=\ave{\Delta Q^2}/\ave{\Nch} constrain the chemical conditions at freeze-out. We also discuss the influence of the limited detector acceptance on fluctuation measurements, and show how this can be accounted for within a quantitative analysis.Comment: Accepted for publication by Physical Review

Forward-backward correlations in nucleus-nucleus collisions: baseline contributions from geometrical fluctuations

We discuss the effects of initial collision geometry and centrality bin definition on correlation and fluctuation observables in nucleus-nucleus collisions. We focus on the forward-backward correlation coefficient recently measured by the STAR Collaboration in Au+Au collisions at RHIC. Our study is carried out within two models: the Glauber Monte Carlo code with a `toy' wounded nucleon model and the hadron-string dynamics (HSD) transport approach. We show that strong correlations can arise due to averaging over events in one centrality bin. We, furthermore, argue that a study of the dependence of correlations on the centrality bin definition as well as the bin size may distinguish between these `trivial' correlations and correlations arising from `new physics'.Comment: 12 pages, 6 figure

Specific Microbial Communities Are Selected in Minimally-Processed Fruit and Vegetables according to the Type of Product

Fruits and vegetables (F&V) products are recommended for the daily diet due to their low caloric content, high amount of vitamins, minerals and fiber. Furthermore, these foods are a source of various phytochemical compounds, such as polyphenols, flavonoids and sterols, exerting antioxidant activity. Despite the benefits derived from eating raw F&V, the quality and safety of these products may represent a source of concern, since they can be quickly spoiled and have a very short shelf-life. Moreover, they may be a vehicle of pathogenic microorganisms. This study aims to evaluate the bacterial and fungal populations in F&V products (i.e., iceberg lettuces, arugula, spinaches, fennels, tomatoes and pears) by using culture-dependent microbiological analysis and high-throughput sequencing (HTS), in order to decipher the microbial populations that characterize minimally-processed F&V. Our results show that F&V harbor diverse and product-specific bacterial and fungal communities, with vegetables leaf morphology and type of edible fraction of fruits exerting the highest influence. In addition, we observed that several alterative (e.g., Pseudomonas and Aspergillus) and potentially pathogenic taxa (such as Staphylococcus and Cladosporium) are present, thus emphasizing the need for novel product-specific strategies to control the microbial composition of F&V and extend their shelf-life

Strange Hadron Resonances and QGP Freeze-out

We describe how the abundance and distribution of hyperon resonances can be used to probe freeze-out conditions. We demonstrate that resonance yields allow us to measure the time scales of chemical and thermal freeze-outs. This should permit a direct differentiation between the explosive sudden, and staged adiabatic freeze-out scenarios.Comment: 8 pages including 4 figures, in Proceedings of Strange Quark Matter 2001, Frankfurt, submitted to J. Phys. G version 2: refernces corrected/added, numercial corrections in figures 2,3,

Active caseinate/guar gum films incorporated with gallic acid: Physicochemical properties and release kinetics

Composite active films based on sodium caseinate/guar gum were prepared by the incorporation of gallic acid at different concentrations to investigate its effect on the structure, physicochemical properties, and the release kinetics from the film. The incorporation of gallic acid imparted changes in the FT-IR spectra. Water vapor permeability (WVP) of films decreased up to 21% after the incorporation of gallic acid in the film. The gallic acid released from the films GAI*60 μg.ml−1, GAII*250 μg.ml−1 and GAIII*650 μg.ml−1 was 67%, 32% and 30% respectively. Similarly, the diffusion coefficient was also affected by an increase in the concentration and was: 8.10 × 10−12 m2s−1, 6.23 × 10−12 m2s−1, and 4.5 × 10−12 m2s−1 for GAI, GAII and GAIII films respectively. Molecular docking suggested the potential inactivation of oxidative enzymes due to binding of gallic acid near their active sites. Therefore, gallic acid releasing films maybe considered as an active food packaging for fruits and vegetables (F&V)

Active packaging based on PLA and chitosan-caseinate enriched rosemary essential oil coating for fresh minced chicken breast application

Active packaging systems are considered an effective way to prolong the shelf life of fresh food products. This study compared five different biopolymer films for their ability to delay the lipid oxidation of raw chicken meat. New antioxidant poly lactic acid film was prepared by coating the film surface with chitosan or chitosan/caseinate blend enriched with rosemary essential oil at concentration of 1% and 2%. Films were characterized in terms of microstructure, water vapor permeability, mechanical properties, and antioxidant capacity. In vivo study was done using fresh minced chicken meats stored at 4 °C and analysed after 0, 4, 7, 11, 14, 21 days. Results indicated that water vapor transmission rate was reduced by the presence of the coating and assumed the lowest value (1.23 ± 0.03 × 10−4 g m-2 s-1) with coating enriched with 2% of rosemary essential oils. The films showed an antioxidant capacity of maximum 6% equivalent to the antioxidant capacity of 6,25 μg of REO/mL. Results from in vivo test showed that the active films were able to reduce meat oxidation during storage in anaerobic modified atmosphere condition: samples packed with active film showed constant malondialdehyde (MDA) and colour up to 14 days and reduction of heptanal and ethanol concentration compared to samples packed with control film (72 % and 90 % respectively). Overall, this study has demonstrated that PLA films coated with an active coating are a promising delivery method for providing antioxidant effects in packaging for fresh meat products

Strangeness, Equilibration, Hadronization

In these remarks I explain the motivation which leads us to consider chemical nonequilibrium processes in flavor equilibration and in statistical hadroniziation of quark--gluon plasma (QGP). Statistical hadronization allowing for chemical non-equilibrium is introduced. The reesults of fits to RHIC-130 results, including multistrange hadrons, are shown to agree only with the model of an exploding QGP fireball.Comment: 8 pages including one figure, discussion contribution at Strange Quark Matter 2001, Frankfurt, submitted to J. Phys.

Sensitivity of Azimuthal Jet Tomography to Early Time Energy-Loss at RHIC and LHC

We compute the jet path-length dependence of energy-loss for higher azimuthal harmonics of jet-fragments in a generalized model of energy-loss that can interpolate between pQCD and AdS/CFT limits and compare results with Glauber and CGC/KLN initial conditions. We find, however, that even the high-pT second moment is most sensitive to the poorly known early-time evolution during the first fm/c. Moreover, we demonstrate that quite generally the energy and density-dependence leads to an overquenching jet fragments relative to the first LHC $R_{AA}$-data, once the parameters of the energy-loss model are fixed from $R_{AA}$-data at RHIC.Comment: 4 pages, 2 figures, version accepted for publication in J. Phys. G: Nucl. Part. Phys. as conference proceedings for Quark Matter 2011, May 23 - May 28, Annecy, Franc