1,014 research outputs found

    Large Formal Wikis: Issues and Solutions

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    We present several steps towards large formal mathematical wikis. The Coq proof assistant together with the CoRN repository are added to the pool of systems handled by the general wiki system described in \cite{DBLP:conf/aisc/UrbanARG10}. A smart re-verification scheme for the large formal libraries in the wiki is suggested for Mizar/MML and Coq/CoRN, based on recently developed precise tracking of mathematical dependencies. We propose to use features of state-of-the-art filesystems to allow real-time cloning and sandboxing of the entire libraries, allowing also to extend the wiki to a true multi-user collaborative area. A number of related issues are discussed.Comment: To appear in The Conference of Intelligent Computer Mathematics: CICM 201

    New Spins for ground states and isomers in 115^{115}Pd and 117^{117}Pd

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    Levels in 115Pd and 117Pd nuclei, populated in the spontaneous fission of 248Cm were studied by means of prompt gamma spectroscopy using the EUROGAM2 array of Anti-Compton spectrometers. Negative-parity, I = 9/2 excitations were identified, which are associated with the long-lived isomers in these nuclei, reported previously as 11/2- excitations. The new data indicate spin and parity 3/2 + for ground states in 115Pd and 117Pd instead of 5/2 + proposed in previous works. This result implicates changes of spin assignments to other levels in both nuclei

    Chiral unitary approach to S-wave meson baryon scattering in the strangeness S=0 sector

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    We study the S-wave interaction of mesons with baryons in the strangeness S=0 sector in a coupled channel unitary approach. The basic dynamics is drawn from the lowest order meson baryon chiral Lagrangians. Small modifications inspired by models with explicit vector meson exchange in the t-channel are also considered. In addition the pi pi N channel is included and shown to have an important repercussion in the results, particularly in the isospin 3/2 sector.Comment: 23 pages, LaTeX, 21 figure

    Chiral Symmetry and light resonances in hot and dense matter

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    We present a study of the ππ\pi\pi scattering amplitude in the σ\sigma and ρ\rho channels at finite temperature and nuclear density within a chiral unitary framework. Meson resonances are dynamically generated in our approach, which allows us to analyze the behavior of their associated scattering poles when the system is driven towards chiral symmetry restoration. Medium effects are incorporated in three ways: (a) by thermal corrections of the unitarized scattering amplitudes, (b) by finite nuclear density effects associated to a renormalization of the pion decay constant, and complementarily (c) by extending our calculation of the scalar-isoscalar channel to account for finite nuclear density and temperature effects in a microscopic many-body implementation of pion dynamics. Our results are discussed in connection with several phenomenological aspects relevant for nuclear matter and Heavy-Ion Collision experiments, such as ρ\rho mass scaling vs broadening from dilepton spectra and chiral restoration signals in the σ\sigma channel. We also elaborate on the molecular nature of ππ\pi\pi resonances.Comment: 14 pages, 14 figures. Contribution to Hard Probes 2008, Illa de A Toxa, Spain, June 8th-14th 200

    Shape coexistence in the very neutron-rich odd-odd 96Rb^{96}Rb

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    Microsecond isomers of neutron-rich nuclei in the masses A=96 and 98 were reinvestigated at the ILL reactor (Grenoble). These nuclei were produced by thermal-neutron induced fission of 241^{241}Pu. The detection is based on time correlation between fission fragments selected by the Lohengrin mass spectrometer, and the γ\gamma rays and conversion electrons from the isomers. A new level scheme of 96^{96}Rb is proposed. We have found that the ground state and low-lying levels of this nucleus are rather spherical, while a rotational band develops at 461 keV energy. This bans has properties consistent with a π[4313/2]xν[5413/2]K=3\pi[431 3/2] x \nu[541 3/2]K = 3^- Nilsson assignment and a deformation β2>0.28\beta_2 > 0.28. It is fed by a 1010^- microsecond isomer consistent with a π(g9/2)ν(h11/2)\pi(g_{9/2})\nu(h_{11/2}) sperical configuration. It is interesting to note that the same unique-parity states π(g9/2)\pi(g_{9/2}) and ν(h11/2)\nu(h_{11/2}) are present in the same nucleus in a deformed and in a spherical configuration. The neighbouring odd-odd nucleus 98^{98}Y presents a strong analogy with 96^{96}Rb and is also discussed

    High spin microsecond isomers in 129^{129}In and 129^{129}Sb

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    In this work the microsecond isomers in 129In and 129Sb were investigated. These nuclei were produced by the thermal-neutron-induced fission of 241Pu. The detection is based on a time correlation between the fission fragments selected by the LOHENGRIN spectrometer at the ILL (Grenoble) and the γ rays or conversion electrons from the isomers. The decay schemes of the new 17/2− isomer in 129In and 23/2+ isomer in 129Sb are reported. A shell-model study of these two nuclei was performed using a realistic effective interaction derived from the CD–Bonn nucleon-nucleon potential. Comparison shows that the calculated energy levels and electromagnetic transition rates are in very good agreement with the experimental data. (APS

    Rotura del ligamento cruzado posterior de la rodilla asociada a fractura de fémur o tibia homolateral

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    Los autores llaman la atención sobre la frecuente asociación de roturas del ligamento cruzado posterior (LCP) a ciertos tipos de fractura del miembro inferior Se revisan 10 casos: 6 asociados a fractura de fémur, y 4 casos asociados a fractura de tibia. Destacan en todos la igualdad en el mecanismo de producción y la frecuencia con que pasa desapercibida la lesión del ligamento hasta la completa resolución de la fractura acompañante, con un peor pronóstico del tratamiento mediante plastias sustitutivas y no mediante simple icinserción en la fase aguda. Por lo tanto, ante todo traumatizado con fracturas de fémur y/o de tibia producidas con la extremidad en flexión (accidente de moto, choque frontal) se debe sospechar la lesión del LCP, explorarlo clínica y radiográficamente y tratarlo cuando hayamos estabilizado la fractura acompañante

    Predicting Plasma Leptin With Anthropometric & Bioelectrical Impedance Analysis Measures Of Adiposity In Multiethnic Young Adult Population In Malaysia

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    Obesity bears multivariate causes and manifestations. Simple anthropometric and non-invasive physical markers are being proposed for easy and early detection of obesity-induced disrupted energy homeostasis and metabolic disorders. Adipose-tissuederived hormone, leptin is largely known for its role in energy homeostasis and paradoxically, higher serum leptin corresponds to higher degree of obesity. Thus, this study aims to investigate the association of plasma leptin with common physical measures of adiposity in a multiethnic, young adult Malaysian population. Methodology: Based on BMI, 185 volunteering participants were grouped as underweight, normal weight, overweight and obese. Standardized anthropometric and bio-electrical impedance assessment (BIA) measure of adiposity was done using Karada Scanner while plasma leptin was measured using a sandwich ELISA assay technique. Results: A total of 61, 45, 56 and 23 Malaysian Malays, Chinese, Indian and other minor groups, respectively were included in this study. Out of this, 28 were underweight, 100 were normal weight, 29 were overweight and 27 were obese (n=27). One-way ANOVA revealed a significant difference among all variables except height and waist-hip ratio. The multiple regression analysis predicted plasma leptin value based on age, weight, height, body age, resting metabolic rate, visceral fat, total body fat, and body mass index in both male (R2=0.54) and females (R2=0.23). The results show that weight, resting metabolic rate, visceral fat and body were reliable predictors for plasma leptin between all the groups. Conclusion: Anthropometric indices can be used as predictors of serum leptin in adults irrespective of their body weight. This observation thus emphasizes the clinical significance of simple non-invasive physical markers for detection of obesity-induced metabolic disorders

    Discovering Regulatory Overlapping RNA Transcripts

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    STEREO is a novel algorithm that discovers cis-regulatory RNA interactions by assembling complete and potentially overlapping same-strand RNA transcripts from tiling expression data. STEREO first identifies coherent segments of transcription and then discovers individual transcripts that are consistent with the observed segments given intensity and shape constraints. We used STEREO to identify 1446 regions of overlapping transcription in two strains of yeast, including transcripts that comprise a new form of molecular toggle switch that controls gene variegation
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