Non-Markovian Dynamics of Quantum Discord

We evaluate the quantum discord dynamics of two qubits in independent and common non-Markovian environments. We compare the dynamics of entanglement with that of quantum discord. For independent reservoirs the quantum discord vanishes only at discrete instants whereas the entanglement can disappear during a finite time interval. For a common reservoir, quantum discord and entanglement can behave very differently with sudden birth of the former but not of the latter. Furthermore, in this case the quantum discord dynamics presents sudden changes in the derivative of its time evolution which is evidenced by the presence of kinks in its behavior at discrete instants of time.Comment: 6 pages, 4 figure

Spinocerebellar ataxias: genotype-phenotype correlations in 104 Brazilian families

OBJECTIVE: Spinocerebellar ataxias are neurodegenerative disorders involving the cerebellum and its connections. There are more than 30 distinct subtypes, 16 of which are associated with an identified gene. The aim of the current study was to evaluate a large group of patients from 104 Brazilian families with spinocerebellar ataxias. METHODS: We studied 150 patients from 104 families with spinocerebellar ataxias who had received molecular genetic testing for spinocerebellar ataxia types 1, 2, 3, 6, 7, 8, 10, 12, 17, and dentatorubral-pallidoluysian atrophy. A statistical analysis of the results was performed using basic descriptive statistics and the correlation coefficient (r), Student's t-test, chi-square test, and Yates' correction. The statistical significance level was established for p-value

BRS - Prata Caprichosa.

BRS - Prata Caprichosa: cultivar de bananeira resistente à sigatoka-negra. Características fitotécnicas da BRS - Prata Caprichosa. Reação da BRS - Prata Caprichosa a doenças e pragas.bitstream/item/126443/1/Folder-Prata-Caprichosa.pd

The AMS-RICH velocity and charge reconstruction

The AMS detector, to be installed on the International Space Station, includes a Ring Imaging Cerenkov detector with two different radiators, silica aerogel (n=1.05) and sodium fluoride (n=1.334). This detector is designed to provide very precise measurements of velocity and electric charge in a wide range of cosmic nuclei energies and atomic numbers. The detector geometry, in particular the presence of a reflector for acceptance purposes, leads to complex Cerenkov patterns detected in a pixelized photomultiplier matrix. The results of different reconstruction methods applied to test beam data as well as to simulated samples are presented. To ensure nominal performances throughout the flight, several detector parameters have to be carefully monitored. The algorithms developed to fulfill these requirements are presented. The velocity and charge measurements provided by the RICH detector endow the AMS spectrometer with precise particle identification capabilities in a wide energy range. The expected performances on light isotope separation are discussed.Comment: Contribution to the ICRC07, Merida, Mexico (2007); Presenter: F. Bara

Seroprevalence of leptospirosis in reproductive-age bovine females in the state of Bahia, Northeastern Brazil

O objetivo do presente trabalho foi determinar a soroprevalência da leptospirose em fêmeas bovinas em idade reprodutiva no Estado da Bahia. A amostragem foi delineada para a determinação da prevalência de propriedades positivas (focos) e de animais soropositivos para a leptospirose. O Estado foi dividido em quatro regiões ou estratos amostrais, nos quais foramexaminadas 10.823 fêmeas bovinas com idade ≥24 meses distribuídas em 1.414 propriedades. A reação de Soroaglutinação Microscópica (SAM), empregando 23 sorovares de Leptospira spp. como antígenos, foi utilizada como teste diagnóstico. O rebanho foi considerado foco quando apresentou pelo menos um animal soropositivo. As prevalências de foco e de animais soropositivos no Estado foram de 77,93% [IC 95% = 75,73% – 79.99%] e 45,42% [IC 95% = 42,00% – 48,88%], respectivamente.O sorovar mais frequente foi o Hardjo (Hardjoprajitno), em 34,49% [IC 95% = 31,93% – 37,14%] daspropriedades positivas e 14,95% [IC 95% = 12,59% - 17,67%] de animais soropositivos de diferentes regiõesThe aim of this work was to determine the seroprevalence of leptospirosis in reproductive-age bovine females in Bahia State, Northeastern Brazil. The sampling was delineated for the determination of the prevalence of seropositive animals as well as herds positive for bovine leptospiroses (foci). The state was divided into 4 regions or sampling strata in which 10,823 bovine females aged ≥24 months allocated in 1,414 herds were sampled. The microscopic agglutination test (MAT), using 23 Leptospira spp. serovars as antigens, was employed as a diagnostic test. The herd was considered positive if at least one animal was seropositive. The prevalences of positive herds and seropositive animals in the state were 77.93% [75.73%–79.99%] and 45.42% [42.00%–48.88%], respectively. Serovar Hardjo (Hardjoprajitno) was the most frequent, with 34.49% [31.93%–37.14%] of positive herds and 14.95% [12.59%–17.67%] of seropositive animals in the different region

The RICH detector of the AMS-02 experiment: status and physics prospects

The Alpha Magnetic Spectrometer (AMS), whose final version AMS-02 is to be installed on the International Space Station (ISS) for at least 3 years, is a detector designed to measure charged cosmic ray spectra with energies up to the TeV region and with high energy photon detection capability up to a few hundred GeV. It is equipped with several subsystems, one of which is a proximity focusing RICH detector with a dual radiator (aerogel+NaF) that provides reliable measurements for particle velocity and charge. The assembly and testing of the AMS RICH is currently being finished and the full AMS detector is expected to be ready by the end of 2008. The RICH detector of AMS-02 is presented. Physics prospects are briefly discussed.Comment: 5 pages. Contribution to the 10th ICATPP Conference on Astroparticle, Particle, Space Physics, Detectors and Medical Physics Applications (Como 2007). Presenter: Rui Pereir