Magnetic Field Line Escape: Comparison with Mean Free Path

In the present work, we determine the fraction of magnetic field lines that reach the tokamak wall leaving the plasma surrounded by a chaotic layer created by resonant perturbations at the plasma edge. The chaotic layer arises in a scenario where an integrable magnetic field with reversed magnetic shear is perturbed by an ergodic magnetic limiter. For each considered line, we calculate its connection length, i.e. the number of toroidal turns that the field lines complete before reaching the wall. We represent the results in the poloidal section in which the initial coordinates are chosen. We also estimate the radial profile of the fraction of field lines, for different temperatures, whose connection lengths are smaller than the electron collisional mean free path.

Two-dimensional electron states bound to an off-plane donor in a magnetic field

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Disparity between Multilocus Enzyme Electrophoresis, Microsatellite Markers and Pulsed-Field Gel Electrophoresis in epidemiological tracking of Candida albicans

Various molecular systems are available for epidemiological, genetic, evolutionary, taxonomic and systematic studies of innumerable fungal infections, especially those caused by the opportunistic pathogen C. albicans. A total of 75 independent oral isolates were selected in order to compare Multilocus Enzyme Electrophoresis (MLEE), Electrophoretic Karyotyping (EK) and Microsatellite Markers (Simple Sequence Repeats - SSRs), in their abilities to differentiate and group C. albicans isolates (discriminatory power), and also, to evaluate the concordance and similarity of the groups of strains determined by cluster analysis for each fingerprinting method. Isoenzyme typing was performed using eleven enzyme systems: Adh, Sdh, M1p, Mdh, Idh, Gdh, G6pdh, Asd, Cat, Po, and Lap (data previously published). The EK method consisted of chromosomal DNA separation by pulsed-field gel electrophoresis using a CHEF system. The microsatellite markers were investigated by PCR using three polymorphic loci: EF3, CDC3, and HIS3. Dendrograms were generated by the SAHN method and UPGMA algorithm based on similarity matrices (S(SM)). The discriminatory power of the three methods was over 95%, however a paired analysis among them showed a parity of 19.7-22.4% in the identification of strains. Weak correlation was also observed among the genetic similarity matrices (S(SM)(MLEE) x S(SM)(EK) x S(SM)(SSRs)). Clustering analyses showed a mean of 9 +/- 12.4 isolates per cluster (3.8 +/- 8 isolates/taxon) for MLEE, 6.2 +/- 4.9 isolates per cluster (4 +/- 4.5 isolates/taxon) for SSRs, and 4.1 +/- 2.3 isolates per cluster (2.6 +/- 2.3 isolates/taxon) for EK. A total of 45 (13%), 39(11.2%), 5 (1.4%) and 3 (0.9%) clusters pairs from 347 showed similarity (Si) of 0.1-10%, 10.1-20%, 20.1-30% and 30.1-40%, respectively. Clinical and molecular epidemiological correlation involving the opportunistic pathogen C. albicans may be attributed dependently of each method of genotyping (i.e., MLEE, EK, and SSRs) supplemented with similarity and grouping analysis. Therefore, the use of genotyping systems that give results which offer minimum disparity, or the combination of the results of these systems, can provide greater security and consistency in the determination of strains and their genetic relationships. (C) 2010 Elsevier B.V. All rights reserved.

Field study on nematode resistance in Nelore-breed cattle

The present study evaluated Nelore cattle with different degrees of resistance to natural infections by gastrointestinal nematodes. One hundred weaned male cattle, 11-12 months of age, were kept on the same pasture and evaluated from October 2003 to February 2004. Faecal and blood samples were collected for parasitological, haematological and immunological tests. In February 2004, the 10 most resistant and the 10 most susceptible animals were selected based on individual means of nematode faecal egg counts (FEC). Such animals were slaughtered for worm burden determination and nematode species identification. The repeatability estimates for FEC (+/- S.D.), log-transformed FEC and packed-cell volume (PCV) in all animals were 0.3 (+/- 0.05), 0.26 (+/- 0.04) and 0.42 (+/- 0.05), respectively. The resistant group showed lower FEC and worm burdens than the susceptible group (P < 0.05). There were no significant differences between groups regarding mean body weight, weight gain, PCV and total serum protein values (P > 0.05). The resistant group showed higher total serum IgE levels (P < 0.05) and higher mean eosinophil blood counts. However, the latter was statistically significant only 42 days after the beginning of the study. Nematodes Cooperia punctata and Haemonchus placei were predominant and the correlation between Cooperia and Haemonchus burdens was 0.64 (P < 0.05), which indicated that animals presenting increased numbers of one of those genera probably had increased numbers of the other. The current study provides further evidence of IgE active role in nematode immunity and suggests that total serum IgE level might serve as an additional marker to select Nelore cattle that are responsive to H. placei and C. punctata infections. (C) 2007 Elsevier B.V. All rights reserved.

Bekenstein bound in asymptotically free field theory

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Yttrium oxysulfide nanosized spherical particles doped with Yb and Er or Yb and Tm: efficient materials for up-converting phosphor technology field

This work reports on the preparation, structural and luminescent studies of nanosized up-converter phosphors Y2O2S:Yb(4%), Er(0.1%) and Y2O2S:Yb(4%), Tm(0.1%),both from polymeric and basic carbonate precursors. The precursors were submitted to a sulphuration process that was previously developed for oxysulfide preparation from basic carbonate. From XRD data, all phosphors presented the oxysulfide phase and the mean crystallite size estimated from the Scherrer formula in the range of 15-20 nm. Polymeric precursor leads to the smallest crystallite size independent on the doping ion. SEM and TEM results confirmed that basic carbonate leads to spherical particles with narrow size distribution and mean diameter of 150 nm, and polymeric precursor smaller spherical particles with diameter between 20 and 40 nm. Up-conversion studies under 980 nm laser excitation showed that Er-doped phosphors present strong green emission related to H-2(11/2), S-4(3/2) --> I-4(15/2) Er transitions as well as the red ones, F-4(9/2) --> I-4(15/2). Tm-doped samples show strong blue emission assigned to (1)G(4) --> H-3(6) and also the red ones, related to (1)G(4) --> F-3(4). Therefore, the sulphuration method was successfully applied to prepare nanosized and nanostructured blue and green up-converter oxysulfide phosphors starting from basic carbonate and polymeric precursors. (C) 2003 Elsevier B.V. All rights reserved.

Assessment of anaerobic power of swimmers: the correlation of laboratory tests on an arm ergometer with field tests in a swimming fool

The aim of this study was to verify the correlation between the Wingate arm crank test outputs (peak power, mean power, and fatigue index), obtained on a specific ergometer, and the performance in crawl stroke swim sprints of 14, 25, 50, and 400 m. The experiment was conducted with 9 healthy male volunteers (18.1 +/- 2.2 years of age; 172 +/- 0.04 cm; 67.7 +/- 5.92 kg and 15.7 +/- 4.57% body fat). on determined days, all individuals were submitted to the Wingate arm crank test and crawl freestyle sprints of 14, 25, 50, and 400 m as they were timed with a stopwatch. The peak power, the mean power, and the fatigue index, which were obtained during the Wingate arm crank test, were not significantly correlated with the maximum swim velocities during the crawl free-style tests of 14 (r = 0.40; r = 0.64; r = 0.11), 25 (r = 0.28; r = 0.39; r = -0.27), 50 (r = 0.03; r = 0.09; r = -0.31), and 400 (r = -0.52; r = -0.37; r = -0.65) m respectively. Thus, it is possible to conclude that the Wingate arm crank test is not suitable to assess the anaerobic power of swimmers under the described experimental conditions.

Anomalous transport effects on magnetic field profile in a motional current sheath

The radial magnetic field profile during implosion of a reversed field current sheath in a theta-pinch was investigated through local measurements and simulation of hybrid code. The actual profile was defined by Hermite interpolation polynomial through mean value of the field at discrete radial position of measurements. Simulation profile was provided by the numerical code with appropriate initial conditions. Classical and anomalous collision process were taken in account in the theoretical model. The results indicated that anomalous effects play major role during the implosion phase of current sheath in a slow rising theta pinch device.

Assessment of Anaerobic Power of Swimmers: The Correlation of Laboratory Tests on an Arm Ergometer with Field Tests in a Swimming Pool

The aim of this study was to verify the correlation between the Wingate arm crank test outputs (peak power, mean power, and fatigue index), obtained on a specific ergometer, and the performance in crawl stroke swim sprints of 14, 25, 50, and 400 m. The experiment was conducted with 9 healthy male volunteers (18.1 ± 2.2 years of age; 172 ± 0.04 cm; 67.7 ± 5.92 kg and 15.7 ± 4.57% body fat). On determined days, all individuals were submitted to the Wingate arm crank test and crawl freestyle sprints of 14, 25, 50, and 400 m as they were timed with a stopwatch. The peak power, the mean power, and the fatigue index, which were obtained during the Wingate arm crank test, were not significantly correlated with the maximum swim velocities during the crawl freestyle tests of 14 (r = 0.40; r = 0.64; r = 0.11), 25 (r = 0.28; r = 0.39; r = -0.17), 50 (r = 0.03; r = 0.09; r = -0.31), and 400 (r = -0.52; r = -0.37; r = -0.65) m, respectively. Thus, it is possible to conclude that the Wingate arm crank test is not suitable to assess the anaerobic power of swimmers under the described experimental conditions.

Evaluation of Brazilian sugarcane genotypes for resistance to Sugarcane mosaic virus under greenhouse and field conditions

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Susceptibility of Rhipicephalus (Boophilus) microplus to ivermectin (200, 500 and 630 mu g/kg) in field studies in Brazil

The present study aimed to determine the susceptibility of 17 Rhipicephalus (Boophilus) microplus populations, originating in the Southeast and Southern regions of Brazil, to different ivermectin concentrations (200, 500 and 630 mu g/kg), administered through subcutaneous or topical (pour-on) routes. R. (B.) microplus populations from the states of Minas Gerais (seven populations), Sao Paulo (seven populations) and Parana (three populations) were chosen for the tests. The selected cattle were allocated to treatment groups on day 0, and block formation was based on the arithmetic mean of female ticks (4.5-8.0 mm long) counted on three consecutive days (-3, -2 and -1). To evaluate the therapeutic and residual efficacies of these formulations, tick counts (females ranging from 4.5 to 8.0 mm long) were performed on days 3,7 and 14 post-treatment, and continued on a weekly basis thereafter until the end of each experiment. The results obtained throughout this study, utilizing field efficacy studies, allowed us to conclude that the resistance of R. (B.) microplus against 200 and 500 mu g/kg ivermectin is widely disseminated because all tick populations that had contact with these specific concentrations were diagnosed as resistant. However, it is possible to infer that R. (B.) microplus resistance against 630 mu g/kg ivermectin was also widespread, diagnosed at six of ten analyzed properties. Resistance of these ectoparasites to 630 mu g/kg ivermectin is most likely emerging in three other populations of R. (B.) microplus. Strategies of resistance management need to be quickly determined to keep the selection pressure at a minimum level in Brazil. (C) 2014 Elsevier B.V. All rights reserved.

Experimental and field record of preferred temperature in the neotropical amphisbaenid Amphisbaena mertensi stauch (reptilia, amphisbaenidae)

1. 1. Temperature preference in experimental thermal gradient in the laboratory was determined and field preferred temperature was recorded, for Amphisbaena mertensi. 2. 2. Mean preferred temperature in 52 experiments averaged 21.4°C which was close to those recorded in 16 specimens measured in the field (21.1°C). 3. 3. Selected temperature varied from 12 to 27°C in the laboratory, and data taken in the field ranged from 18 to 26°C. © 1984.