Search results for "Conducta"
showing 10 items of 611 documents
Zero-bias conductance peak in detached flakes of superconducting 2H-TaS2probed by scanning tunneling spectroscopy
2014
We report an anomalous tunneling conductance with a zero-bias peak in flakes of superconducting 2$H$-${\mathrm{TaS}}_{2}$ detached through mechanical exfoliation. To explain the observed phenomenon, we construct a minimal model for a single unit cell layer of superconducting 2$H$-${\mathrm{TaS}}_{2}$ with a simplified two-dimensional Fermi surface and a sign-changing Cooper-pair wave function induced by Coulomb repulsion. Superconductivity is induced in the central $\ensuremath{\Gamma}$ pocket, where it becomes nodal. We show that weak scattering at the nodal Fermi surface, produced by nonperturbative coupling between tip and sample, gives Andreev states that lead to a zero-bias peak in the…
Evidence for metastable photo-induced superconductivity in K3C60
2021
Far and mid infrared optical pulses have been shown to induce non-equilibrium unconventional orders in complex materials, including photo-induced ferroelectricity in quantum paraelectrics, magnetic polarization in antiferromagnets and transient superconducting correlations in the normal state of cuprates and organic conductors. In the case of non-equilibrium superconductivity, femtosecond drives have generally resulted in electronic properties that disappear immediately after excitation, evidencing a state that lacks intrinsic rigidity. Here, we make use of a new optical device to drive metallic K$_3$C$_{60}$ with mid-infrared pulses of tunable duration, ranging between one picosecond and o…
Energy gap of intermediate-valentSmB6studied by point-contact spectroscopy
2001
We have investigated the intermediate valence narrow-gap semiconductor ${\mathrm{SmB}}_{6}$ at low temperatures using both conventional spear-anvil type point contacts as well as mechanically controllable break junctions. The zero-bias conductance varied between less than $0.01 \ensuremath{\mu}\mathrm{S}$ and up to 1 mS. The position of the spectral anomalies, which are related to the different activation energies and band gaps of ${\mathrm{SmB}}_{6},$ did not depend on the the contact size. Two different regimes of charge transport could be distinguished: Contacts with large zero-bias conductance are in the diffusive Maxwell regime. They had spectra with only small nonlinearities. Contacts…
MICROWAVE EFFECTS ON ACETYLCHOLINE-INDUCED CHANNELS IN CULTURED CHICK MYOTUBES
1988
The behavior of cultured myotubes from chick embryos exposed to microwaves has been experimentally analyzed. Recordings of acetylcholine-induced currents have been obtained via patch-clamp techniques using both cell-attached (single-channel current recording) and whole-cell (total current recording) configurations. During the exposure to low-power microwaves the frequency of the ACh-activated single channel openings decreased, while the ACh-induced total current showed a faster falling phase. Channel open time and conductance were not affected by microwave irradiation. It is concluded that the exposure to microwaves increases the rate of desensitization and decreases the channel opening pro…
Moderate-Vigorous Physical Activity across Body Mass Index in Females : Moderating Effect of Endocannabinoids and Temperament
2014
Altres ajuts: This manuscript was supported by grants from Instituto Salud Carlos III (FIS PI11/210 and CIBERobn). Sarah Sauchelli is recipient of a pre-doctoral Grant (2013-17) by IDIBELL. Jose C. Fernández-García is recipient of a 'Rio Hortega' contract from 'Instituto de Salud Carlos III', Madrid, Spain (CM12/00059). The funders had no role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. Endocannabinoids and temperament traits have been linked to both physical activity and body mass index (BMI) however no study has explored how these factors interact in females. The aims of this cross-sectional study were to 1) examine differences…
Physiological,anatomical and biomass partitioning responses to ozone in the Mediterranean endemic plant Lamottea dianae
2011
Ozone effects on the perennial forb Lamottea dianae were studied in an open-top chamber experiment. Ozone was found to induce reductions in CO 2 assimilation and water use efficiency in the leaves of this species. These reductions were mainly related to a decline in the in vivo CO 2 fixation capacity of Rubisco (V c,max), rather than to stomatal limitations or photoinhibitory damage (F v:F m). In addition to chloroplast degeneration, other observed effects were callose accumulation, formation of pectinaceous wart-like cell wall exudates and phloem alterations. Moreover, ozone exposure significantly reduced root dry biomass. The possible relevance of these adverse effects for Mediterranean f…
Determination of thermometric parameters from the conductance curve of the normal metal based tunnel junction array
1997
Abstract We propose a method for extracting thermometric parameters from the measured conductance curve, against bias voltage, of a tunnel junction array. Instead of fitting the whole theoretical conductance curve to the experiment, we perform several polynomial fits to selected bias regions. The advantages of this method is that polynomial fits are linear in their fitting parameters whereas the theoretical form for the conductance is inherently nonlinear. This way the proposed method is about three orders of magnitude faster than the nonlinear fit. Optimizing this polynomial fit procedure is discussed.
Civilizar las costumbres: el papel de la prensa periódica dieciochesca
2014
Este articulo pretende ofrecer una nueva mirada sobre la civilidad en los periodicos espanoles del siglo XVIII, inspirada en los recientes estudios sobre la prensa y en la historiografia que ha revelado las tensiones sociales y culturales dirimidas en torno a la nocion de urbanidad. En el se muestra que los periodicos (no solo los de tipo ‘espectador’) fueron un espacio importante en el que se cuestiono, de manera teorica y practica, el sentido de las reglas de conducta tenidas por civilizadas y se experimentaron formulas de intercambio social, en interaccion con el publico. Y ello a traves de la reflexion sobre el propio concepto de civilidad, sus fundamentos morales y sus usos, del tratam…
Contexto familiar de niños con autismo: Implicaciones en el desarrollo social y emocional
2019
Las familias de niños con trastorno del espectro del autismo (TEA) pueden diferenciarse en función de indicadores sociodemográficos y del clima familiar caracterizado por el nivel de estrés parental, el uso de estrategias de afrontamiento y la búsqueda de apoyo social. El objetivo de este estudio fue analizar las diferencias conductuales, emocionales y sociales de niños con TEA en relación con distintas tipologías de familias caracterizadas en función de los factores de riesgo como de riesgo alto, moderado y bajo. Los participantes fueron 52 madres y sus hijos de entre 7 y 11 años, con TEA sin discapacidad intelectual, que aportaron información del desarrollo socioemocional de los hijos med…
EmPeCemos: un programa multicomponente para la prevención indicada de los problemas de conducta y el abuso de drogas
2009
En la última década, un amplio número de investigaciones ha permitido constatar la existencia de trayectorias de desarrollo desadaptativas, asociadas a problemas de conducta de inicio temprano. Estas trayectorias, en las que se implica una compleja cadena de factores familiares, escolares y socioemocionales, dan lugar a desajustes comportamentales crónicos y severos, de difícil tratamiento, incluyendo comportamientos antisociales y abuso de drogas. Por ello, la investigación en prevención subraya la necesidad de una intervención temprana que, actuando sobre los individuos en alto riesgo y su entorno, permita detener el avance hacia patrones severos de desadaptación. En esta línea, se desarr…