Fractionalization noise in edge channels of integer quantum Hall states

A theoretical calculation is presented of current noise which is due charge fractionalization, in two interacting edge channels in the integer quantum Hall state at filling factor $\nu=2$. Because of the capacitive coupling between the channels, a tunneling event, in which an electron is transferred from a biased source lead to one of the two channels, generates propagating plasma mode excitations which carry fractional charges on the other edge channel. When these excitations impinge on a quantum point contact, they induce low-frequency current fluctuations with no net average current. A perturbative treatment in the weak tunneling regime yields analytical integral expressions for the noise as a function of the bias on the source. Asymptotic expressions of the noise in the limits of high and low bias are found

Brote de mastitis clínica por Corynebacterium spp. y Streptococcus dysgalactiae en cabras en Salta, Argentina

Intramammary infections are a serious problem for goat’s milk production worldwide. Staphylococcus spp. are the most prevalent pathogens responsible for intramammary infection in small ruminants; however, there is only little information about goat mastitis in Argentina. The objective of this communication was to describe an outbreak of clinical mastitis affecting 12 of 24 lactating goats. Corynebacterium spp. and Streptococcus dysgalactiae were isolated in pure culture from all milk samples. All the clinical isolates were identified by biochemical tests and subjected to antibiotic susceptibility tests

Contribution to the knowledge of flat bugs from the temperate south america (hemiptera: heteroptera)

New Aradidae findings as localities and provinces are given from Argentina. Mezira regularis Champion is mentioned for the first time for this country. This work includes a result of studied material of Aradidae that belongs to the Museo de La Plata and Fundacion Miguel Lillo (Argentina).Fil: Contreras, Eugenia Fernanda. Universidad Nacional de Jujuy. Instituto de Biología de la Altura; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta; ArgentinaFil: Neder de Román, L. E.. Universidad Nacional de Jujuy. Instituto de Biología de la Altura; ArgentinaFil: Coscarón, M. C.. Universidad Nacional de Jujuy. Instituto de Biología de la Altura; Argentin

Current-voltage correlations in interferometers

We investigate correlations of current at contacts and voltage fluctuations at voltage probes coupled to interferometers. The results are compared with correlations of current and occupation number fluctuations at dephasing probes. We use a quantum Langevin approach for the average quantities and their fluctuations. For higher order correlations we develop a stochastic path integral approach and find the generating functions of voltage or occupation number fluctuations. We also derive a generating function for the joint distribution of voltage or occupation number at the probe and current fluctuations at a terminal of a conductor. For energy independent scattering we found earlier that the generating function of current cumulants in interferometers with a one-channel dephasing or voltage probe are identical. Nevertheless, the distribution function for voltage and the distribution function for occupation number fluctuations differ, the latter being broader than that of former in all examples considered here.Comment: 23 pages, 10 figures, minor changes, additional appendix, added reference

Fermionic Mach-Zehnder interferometer subject to a quantum bath

We study fermions in a Mach-Zehnder interferometer, subject to a quantum-mechanical environment leading to inelastic scattering, decoherence, renormalization effects, and time-dependent conductance fluctuations. Both the loss of interference contrast as well as the shot noise are calculated, using equations of motion and leading order perturbation theory. The full dependence of the shot-noise correction on setup parameters, voltage, temperature and the bath spectrum is presented. We find an interesting contribution due to correlations between the fluctuating renormalized phase shift and the output current, discuss the limiting behaviours at low and high voltages, and compare with simpler models of dephasing.Comment: 5 pages, 3 figure

Direct interpretation of the X-ray and neutron three-dimensional difference pair distribution functions (3D-ΔPDFs) of yttria-stabilized zirconia

Three-dimensional difference pair distribution functions (3D-ΔPDFs) from X-ray and neutron diffraction experiments are reported for yttria-stabilized zirconia (Zr0.82Y0.18O1.91). A quantitative analysis of the signatures in the three-dimensional difference pair distribution functions is used to establish that oxygen ions neighbouring a vacancy shift by 0.525 (5) Å along ⟨1, 0, 0⟩ towards the vacancy while metal ions neighbouring a vacancy shift by 0.465 (2) Å along ⟨1, 1, 1⟩ away from the vacancy. The neutron 3D-ΔPDF shows a tendency for vacancies to cluster along ⟨½, ½, ½⟩, which results in sixfold coordinated metal ions

Seleção precoce de famílias de irmãos-completos de batata.

Clonal selection is the preferred breeding method used in potatoes (Solanum tuberosum L.). However this selection procedure is only efficient for more advanced generations and shows no good results when applied in the seedling up to the second clonal generation. This study assessed the feasibility of selection in early generations of full-sib potato families and compares the selection method among and within families with the combined selection under different selection intensities. Six experiments were conducted from the first (C1) until the third clonal generation (C3). In C1 a randomized complete block design with four replications of 25 plants was used. In the remaining generations RCB was employed with three replications of 10 plants. Genetic variances were lower between families than within families, for all traits, but the heritabilities between families were almost always larger. The expected gains from selection between and within families were superior to gains from the combined selection in any intensity of selection. The selection of families should have weaker intensity than selection among clones within families. The selection of families was more efficient when based on the average of environments

Relationship between work rate and oxygen uptake in mitochondrial myopathy during ramp-incremental exercise

We determined the response characteristics and functional correlates of the dynamic relationship between the rate (Δ) of oxygen consumption ( O2) and the applied power output (work rate = WR) during ramp-incremental exercise in patients with mitochondrial myopathy (MM). Fourteen patients (7 males, age 35.4 ± 10.8 years) with biopsy-proven MM and 10 sedentary controls (6 males, age 29.0 ± 7.8 years) took a ramp-incremental cycle ergometer test for the determination of the O2 on-exercise mean response time (MRT) and the gas exchange threshold (GET). The ΔO2/ΔWR slope was calculated up to GET (S1), above GET (S2) and over the entire linear portion of the response (S T). Knee muscle endurance was measured by isokinetic dynamometry. As expected, peak O2 and muscle performance were lower in patients than controls (P O2/ΔWR than controls, especially the S2 component (6.8 ± 1.5 vs 10.3 ± 0.6 mL·min-1·W-1, respectively; P O2/ΔWR (S T) and muscle endurance, MRT-O2, GET and peak O2 in MM patients (P O2/ΔWR below 8 mL·min-1·W-1 had severely reduced peak O2 values (O2) had lower ΔO2/ΔWR (P O2/ΔWR) is typically reduced in patients with MM, being related to increased functional impairment and higher cardiopulmonary stress

Inspiratory fraction and exercise impairment in COPD patients GOLD stages II-III

The inspiratory-to-total lung capacity ratio or inspiratory fraction (inspiratory capacity (IC)/total lung capacity (TLC)) may be functionally more representative than traditional indices of resting airflow limitation and lung hyperinflation in patients with chronic obstructive pulmonary disease (COPD).In the present retrospective study, a comparison was made of the individual performance of post-bronchodilator IC, IC/TLC and forced expiratory volume in one second (FEV1) in predicting a severely reduced peak oxygen uptake (V'o(2); < 60% predicted) in 44 COPD patients Global Initiative for Chronic Obstructive Lung Disease stages II-III (post-bronchodilator FEV1 ranging from 31-79% pred).Patients with lower IC/TLC values (<= 0.28) showed increased lung volumes and reduced exercise capacity as compared with other subjects. Following a multiple linear regression analysis, only IC/TLC and FEV1 remained as independent predictors of V'o(2) (r(2)=0.33). A receiver operating characteristic (ROC) curve analysis revealed that an IC/TLC <= 0.28 had the highest specificity (89.6%), positive predictive value (80%) and overall accuracy (86.3%) in identifying patients with V'o(2)< 60% pred. in addition, the area under the ROC curve tended to be higher for IC/TLC than IC.In conclusion, post-bronchodilator total lung capacity-corrected inspiratory fraction provides useful information in addition to forced expiratory volume in one second and inspiratory capacity, to estimate the likelihood of chronic obstructive pulmonary disease patients to present with severely reduced maximal exercise capacity.Universidade Federal de São Paulo, Paulista Sch Med, Pulm Funct & Clin Exercise Physiol Unit, Resp Div,Dept Med,EPM, BR-04020050 São Paulo, BrazilUniversidade Federal de São Paulo, Paulista Sch Med, Pulm Funct & Clin Exercise Physiol Unit, Resp Div,Dept Med,EPM, BR-04020050 São Paulo, BrazilWeb of Scienc