Sub-Gap Structure in the Conductance of a Three-Terminal Josephson Junction

Three-terminal superconductor (S) - normal metal (N) - superconductor (S) Josephson junctions are investigated. In a geometry where a T-shape normal metal is connected to three superconducting reservoirs, new sub-gap structures appear in the differential resistance for specific combinations of the superconductor chemical potentials. Those correspond to a correlated motion of Cooper pairs within the device that persist well above the Thouless energy and is consistent with the prediction of quartets formed by two entangled Cooper pairs. A simplified nonequilibrium Keldysh Green's function calculation is presented that supports this interpretation.Comment: To appear in Physical Review

A multi-resolution image reconstruction method in X-ray computed tomography

International audienceWe propose a multiresolution X-ray imaging method designed for non-destructive testing/ evaluation (NDT/NDE) applications which can also be used for small animal imaging studies. Two sets of projections taken at different magnifications are combined and a multiresolution image is reconstructed. A geometrical relation is introduced in order to combine properly the two sets of data and the processing using wavelet transforms is described. The accuracy of the reconstruction procedure is verified through a comparison to the standard filtered backprojection (FBP) algorithm on simulated data

Silicon Superconducting Quantum Interference Device

We have studied a Superconducting Quantum Interference SQUID device made from a single layer thin film of superconducting silicon. The superconducting layer is obtained by heavily doping a silicon wafer with boron atoms using the Gas Immersion Laser Doping (GILD) technique. The SQUID device is composed of two nano-bridges (Dayem bridges) in a loop and shows magnetic flux modulation at low temperature and low magnetic field. The overall behavior shows very good agreement with numerical simulations based on the Ginzburg-Landau equations.Comment: Published in Applied Physics Letters (August 2015

Alcohol-preferring P rats emit spontaneous 22-28 kHz ultrasonic vocalizations that are altered by acute and chronic alcohol experience

BACKGROUND: Emotional states are often thought to drive excessive alcohol intake and influence the development of alcohol use disorders. To gain insight into affective properties associated with excessive alcohol intake, we utilized ultrasonic vocalization (USV) detection and analyses to characterize the emotional phenotype of selectively bred alcohol-preferring (P) rats; an established animal model of excessive alcohol intake. USVs emitted by rodents have been convincingly associated with positive (50-55 kHz frequency-modulated [FM]) and negative (22-28 kHz) affective states. Therefore, we hypothesized that 50-55 and 22-28 kHz USV emission patterns in P rats would reveal a unique emotional phenotype sensitive to alcohol experience. METHODS: 50-55 kHz FM and 22-28 kHz USVs elicited from male P rats were assessed during access to water, 15 and 30% EtOH (v/v). Ethanol (EtOH; n = 12) or water only (Control; n = 4) across 8 weeks of daily drinking-in-the-dark (DID) sessions. RESULTS: Spontaneous 22-28 kHz USVs are emitted by alcohol-naïve P rats and are enhanced by alcohol experience. During DID sessions when alcohol was not available (e.g., "EtOH OFF" intervals), significantly more 22-28 kHz than 50-55 kHz USVs were elicited, while significantly more 50-55 kHz FM than 22-28 kHz USVs were emitted when alcohol was available (e.g., "EtOH ON" intervals). In addition, USV acoustic property analyses revealed chronic effects of alcohol experience on 22-28 kHz USV mean frequency, indicative of lasting alcohol-mediated alterations to neural substrates underlying emotional response. CONCLUSIONS: Our findings demonstrate that acute and chronic effects of alcohol exposure are reflected in changes in 22-28 and 50-55 kHz FM USV counts and acoustic patterns. These data support the notion that initiation and maintenance of alcohol intake in P rats may be due to a unique, alcohol-responsive emotional phenotype and further suggest that spontaneous 22-28 kHz USVs serve as behavioral markers for excessive drinking vulnerability

Alcohol enhances unprovoked 22-28 kHz USVs and suppresses USV mean frequency in High Alcohol Drinking (HAD-1) male rats

Heightened emotional states increase impulsive behaviors such as excessive ethanol consumption in humans. Though positive and negative affective states in rodents can be monitored in real-time through ultrasonic vocalization (USV) emissions, few animal studies have focused on the role of emotional status as a stimulus for initial ethanol drinking. Our laboratory has recently developed reliable, high-speed analysis techniques to compile USV data during multiple-hour drinking sessions. Since High Alcohol Drinking (HAD-1) rats are selectively bred to voluntarily consume intoxicating levels of alcohol, we hypothesized that USVs emitted by HAD-1 rats would reveal unique emotional phenotypes predictive of alcohol intake and sensitive to alcohol experience. In this study, male HAD-1 rats had access to water, 15% and 30% EtOH or water only (i.e., Controls) during 8 weeks of daily 7-h drinking-in-the-dark (DID) sessions. USVs, associated with both positive (i.e., 50-55 kHz frequency-modulated or FM) and negative (i.e., 22-28 kHz) emotional states, emitted during these daily DID sessions were examined. Findings showed basal 22-28 kHz USVs were emitted by both EtOH-Naïve (Control) and EtOH-experienced rats, alcohol experience enhanced 22-28 kHz USV emissions, and USV acoustic parameters (i.e., mean frequency in kHz) of both positive and negative USVs were significantly suppressed by chronic alcohol experience. These data suggest that negative affective status initiates and maintains excessive alcohol intake in selectively bred HAD-1 rats and support the notion that unprovoked emissions of negative affect-associated USVs (i.e., 22-28 kHz) predict vulnerability to excessive alcohol intake in distinct rodent models

Alcohol-Naïve USVs Distinguish Male HAD-1 from LAD-1 Rat Strains

Ultrasonic vocalizations (USVs) are mediated through specific dopaminergic and cholinergic neural pathways and serve as real-time measures of positive and negative emotional status in rodents. Although most USV studies focus primarily on USV counts, each USV possesses a number of characteristics shown to reflect activity in the associated neurotransmitter system. In the present study, we recorded spontaneously emitted USVs from alcohol-naïve high alcohol drinking (HAD-1) and low alcohol drinking (LAD-1) rats. Using our recently developed WAAVES algorithm we quantified four acoustic characteristics (mean frequency, duration, power and bandwidth) from each 22 – 28 kHz and 50 – 55 kHz frequency modulated (FM) USV. This rich USV representation allowed us to apply advanced statistical techniques to identify the USV acoustic characteristics that distinguished HAD-1 from LAD-1 rats. Linear mixed models (LMM) examined the predictability of each USV characteristic in isolation and linear discriminant analysis (LDA) and binomial logistic regression examined the predictability of linear combinations of the USV characteristics as a group. Results revealed significant differences in acoustic characteristics between HAD-1 and LAD-1 rats in both 22 – 28 kHz and 50 – 55 kHz FM USVs. In other words, these rats selectively bred for high- and low-alcohol consumption can be identified as HAD-1 or LAD-1 rats with high classification accuracy (approx. 92-100%) exclusively on the basis of their emitted 22-28 kHz and 50-55 kHz FM USV acoustic characteristics. In addition, acoustic characteristics of 22 – 28 kHz and 50 – 55 kHz FM USVs emitted by alcohol-naïve HAD-1 and LAD-1 rats significantly correlate with their future alcohol consumption. Our current findings provide novel evidence that USV acoustic characteristics can be used to discriminate between alcohol-naïve HAD-1 and LAD-1 rats, and may serve as biomarkers in rodents with a predisposition for, or against, excessive alcohol intake

D.C. Josephson transport by quartets and other Andreev resonances in superconducting bijunctions

7 pagesInternational audienceBijunctions are three-terminal Josephson junctions where three superconductors are connected by a single weak link made of a metallic region or of quantum dots. Biasing two of the superconductors with commensurate voltages yields Andreev resonances that produce d.c. Josephson currents made of correlated Cooper pairs. For instance with applied voltages (0, V, -V ), quartets formed by two entangled Cooper pairs are emitted by one reservoir towards the two others. Theory involving non-equilibrium Green's functions reveal the microsopic mechanism at play, e.g multiple coherent Andreev reflections that provide an energy-conserving and fully coherent channel. Recent experiments on dffusive Aluminum-Copper bijunctions show transport anomalies that are interpreted in terms of quartet resonances

Review on Superconducting Materials

Short review of the topical comprehension of the superconductor materials classes Cuprate High-Temperature Superconductors, other oxide superconductors, Iron-based Superconductors, Heavy-Fermion Superconductors, Nitride Superconductors, Organic and other Carbon-based Superconductors and Boride and Borocarbide Superconductors, featuring their present theoretical understanding and their aspects with respect to technical applications.Comment: A previous version of this article has been published in \" Applied Superconductivity: Handbook on Devices and Applications \", Wiley-VCH ISBN: 978-3-527-41209-9. The new extended and updated version will be published in \" Encyclopedia of Applied Physics \", Wiley-VC

Doctrina penal chilena del siglo XXI: estudio de las escuelas de derecho penal de las universidades del norte de Chile (Arturo Prat, Antofagasta, Católica del Norte y Atacama): especial referencia a la obra del profesor Mario Durán Migliardi

Memoria para optar al grado de Licenciado de Ciencias Jurídicas y SocialesEste trabajo propone la realización de una investigación de carácter cuantitativo y cualitativo que logre reunir y sistematizar los aportes que han hecho a la dogmática penal chilena los académicos de las facultades de derecho de las universidades de las regiones del norte de Chile durante el siglo XXI. De este modo, se intenta identificar cuáles son los principales centros de producción doctrinal que conformarían una posible “Escuela Penal del norte de Chile”. Para lograr los objetivos buscados por esta investigación se hará una recopilación, primero, cuantitativa de las publicaciones realizadas por los profesores que componen las entidades educacionales que abarca este estudio desde el año 2000 en adelante. Así, se pretende advertir desde un punto de vista objetivo el impacto del trabajo de estos académicos en el estudio del derecho penal nacional. Posteriormente, se efectuará un trabajo cualitativo que logre ilustrar el aporte de la escuela de derecho penal de la Universidad de Atacama a la doctrina penal chilena, específicamente a través de la obra del profesor Dr. Mario Durá