618 research outputs found

    CP violation in J/ψΛΛˉJ/\psi \rightarrow \Lambda \bar \Lambda

    Full text link
    We study CP violation in J/ψΛΛˉJ/\psi \rightarrow \Lambda \bar{\Lambda} decay. This decay provides a good place to look for CP violation. Some observables are very sensitive to the Λ\Lambda electric dipole moment dΛd_\Lambda and therefore can be used to improve the experimental upper bound on dΛd_\Lambda. CP violations in the lepton pair decays of J/ψJ/\psi and Υ\Upsilon are also discussed.Comment: 8 pages, RevTex, UM-P-92/113, OZ-92/3

    Testing the Bell Inequality at Experiments of High Energy Physics

    Full text link
    Besides using the laser beam, it is very tempting to directly testify the Bell inequality at high energy experiments where the spin correlation is exactly what the original Bell inequality investigates. In this work, we follow the proposal raised in literature and use the successive decays J/ψγηcΛΛˉpπpˉπ+J/\psi\to\gamma\eta_c\to \Lambda\bar\Lambda\to p\pi^-\bar p\pi^+ to testify the Bell inequality. Our goal is twofold, namely, we first make a Monte-Carlo simulation of the processes based on the quantum field theory (QFT). Since the underlying theory is QFT, it implies that we pre-admit the validity of quantum picture. Even though the QFT is true, we need to find how big the database should be, so that we can clearly show deviations of the correlation from the Bell inequality determined by the local hidden variable theory. There have been some critiques on the proposed method, so in the second part, we suggest some improvements which may help to remedy the ambiguities indicated by the critiques. It may be realized at an updated facility of high energy physics, such as BES III.Comment: 16 pages, 5 figure

    Biodegradation of herbicide diuron by streptomycetes isolated from soil

    Full text link
    The diuron degrading activity of 17 streptomycete strains, obtained from agricultural and non-agricultural soils, was determined in the laboratory. All strains were identified as Streptomyces sp. by phenotypic characteristics and PCR-based assays. The strains were cultivated in liquid medium with diuron (4mgL(-1)) at 25 degrees C for 15 days. Biodegradation activity was deter-mined by high-performance liquid chromatography. The results indicated that all strains were able to degrade diuron, but to different amounts. Twelve strains degraded the herbicide by up to 50% and four of them by up to 70%. Strain A7-9, belonging to S. albidoflavus cluster, was the most efficient organism in the degradation of diuron, achieving 95% degradation after five days of incubation and no herbicide remained after 10 days. Overall, the strains isolated from agricultural soils exhibited higher degradation percentages and rates than those isolated from non-agricultural soils. Given the high degradation activity observed here, the streptomycete strains show a good potential for bioremediation of soils contaminated with diuron. (c) 2006 Elsevier Ltd. All rights reserved.Castillo López, MÁ.; Felis Reig, N.; Aragón Revuelta, P.; Cuesta Amat, G.; Sabater Marco, C. (2006). Biodegradation of herbicide diuron by streptomycetes isolated from soil. International Biodeterioration and Biodegradation. 58(3-4):196-202. doi:10.1016/j.ibiod.2006.06.020S196202583-

    From Research to Operational Biomonitoring of Freshwaters: A Suggested Conceptual Framework and Practical Solutions

    Get PDF
    International audienceThe contradictory demands of managers (quick relevant operational responses) and ecologists (need time for in-depth research) involved in freshwater biomonitoring are still relevant today. To contribute to solving this dilemma, we are proposing a novel biomonitoring approach, which among many others, could be used in this field and further developed in the future. Biomonitoring actions are integrated in conceptual schemes, in which hydrology, chemistry, hydrogeology and geomorphology bear as much importance as biology. Among biomonitoring tools, a harmonization system allows end-users to use a set of qualitative indicators (various biotic indices) and integrate the information given by individual biotic indices. Functional traits and calculation of an ecological potential in porous aquatic habitats (surficial coarse sediments and the hyporheic system) are regarded as a basis for assessing ecological functioning of streams and rivers. This last methodology takes into account the dynamics of water exchanges between surface water and groundwater. Objectives of ecological quality, ecological potentials and resilience capacity that need to be preserved or rehabilitated in aquatic habitats are established. In lakes, a similar approach was followed and a general typology of lake functioning was proposed, including that for urban lakes. All those biomonitoring tools are transferred to end-users and subject to further research. The final purpose is to promote practical high-tech tools which are continually and interactively connected with ongoing research

    High Yields of Shrimp Oil Rich in Omega-3 and Natural Astaxanthin from Shrimp Waste

    Get PDF
    A valued marine oil rich in omega-3 lipids and natural astaxanthin is obtained with remarkably high yield (up to 5 wt %) extending to pink shrimp waste (head and carapace) using the approach to extract fish oil from fish processing byproducts using d-limonene. Biobased limonene is an excellent solvent for both unsaturated lipids and astaxanthin-based carotenoids preventing oxidative degradation during the extraction cycle including solvent separation at 85 °C. Explaining the deep red color of the shrimp oil obtained, computational simulation suggests that d-limonene is also a good solvent for natural astaxanthin abundant in shrimp

    Review: Towards the agroecological management of ruminants, pigs and poultry through the development of sustainable breeding programmes. II. Breeding strategies

    Get PDF
    Agroecology uses ecological processes and local resources rather than chemical inputs to develop productive and resilient livestock and crop production systems. In this context, breeding innovations are necessary to obtain animals that are both productive and adapted to a broad range of local contexts and diversity of systems. Breeding strategies to promote agroecological systems are similar for different animal species. However, current practices differ regarding the breeding of ruminants, pigs and poultry. Ruminant breeding is still an open system where farmers continue to choose their own breeds and strategies. Conversely, pig and poultry breeding is more or less the exclusive domain of international breeding companies which supply farmers with hybrid animals. Innovations in breeding strategies must therefore be adapted to the different species. In developed countries, reorienting current breeding programmes seems to be more effective than developing programmes dedicated to agroecological systems that will struggle to be really effective because of the small size of the populations currently concerned by such systems. Particular attention needs to be paid to determining the respective usefulness of cross-breeding v. straight breeding strategies of well-adapted local breeds. While cross-breeding may offer some immediate benefits in terms of improving certain traits that enable the animals to adapt well to local environmental conditions, it may be difficult to sustain these benefits in the longer term and could also induce an important loss of genetic diversity if the initial pure-bred populations are no longer produced. As well as supporting the value of within-breed diversity, we must preserve between-breed diversity in order to maintain numerous options for adaptation to a variety of production environments and contexts. This may involve specific public policies to maintain and characterize local breeds (in terms of both phenotypes and genotypes), which could be used more effectively if they benefited from the scientific and technical resources currently available for more common breeds. Last but not least, public policies need to enable improved information concerning the genetic resources and breeding tools available for the agroecological management of livestock production systems, and facilitate its assimilation by farmers and farm technicians

    Search for Direct CP Violation in Non-Leptonic Decays of Charged Ξ\Xi and Λ\Lambda Hyperons

    Full text link
    A search for direct CP violation in the non-leptonic decays of hyperons has been performed. In comparing the product of the decay parameters, αΞαΛ\alpha_{\Xi}\alpha_{\Lambda}, in terms of an asymmetry parameter, AΞΛA_{\Xi\Lambda}, between hyperons and anti-hyperons in the charged ΞΛπ\Xi \to \Lambda \pi and Λpπ\Lambda \to p \pi decay sequence, we found no evidence of direct CP violations. The parameter AΞΛA_{\Xi\Lambda} was measured to be 0.012±0.0140.012 \pm 0.014.Comment: Submitted for publication; RevTex, 13 pages, 4 figure
    corecore