Universal Conductance Distributions in the Crossover between Diffusive and Localization Regimes

The full distribution of the conductance $P(G)$ in quasi-one-dimensional wires with rough surfaces is analyzed from the diffusive to the localization regime. In the crossover region, where the statistics is dominated by only one or two eigenchannels, the numerically obtained P(G) is found to be independent of the details of the system with the average conductance as the only scaling parameter. For < e^2/h, P(G) is given by an essentially ``one-sided'' log-normal distribution. In contrast, for e^2/h <= 2e^2/h, the shape of P(G) remarkable agrees with those predicted by random matrix theory for two fluctuating transmission eigenchannels.Comment: Accepted for publication in Phys. Rev. Let

Microinclusions in cassiterite of different deposits in western Spain

[Resumen] Se incluyen en este estudio casiteritas procedentes de distintos yacimientos de Salamanca y Extremadura que se han seleccionado en función de sus diferentes caracteres: hábito, color, zonaci6n, tipología genética y composición química. Se presenta la descripción microscópica así como la composición química obtenida mediante microsonda de las casiteritas y sus microinclusiones. Cabe destacar una clara relación entre la razón Nb/Ta y el tipo genético. Por otro lado, la razón Fe/Mn es característica propia del ambiente geoquímico de cada yacimiento. Las casiteritas ricas en Nb y Ta contienen microinclusiones de columbo-tantalita, las casiteritas ricas en Ti y Nb, ilmeno-rutilo y columbo-tantalita y las esencialmente, titaníferas , rutilos.[Abstract] Cassiterites of different deposits in western Spain were selectioned for this study by different characteristics: colour, crystal habit, zonation, genetic type and chemical composition. Microscopic description and Microprobe analysis of cassiterites and microinclusions are presented. There is correlation between columbite-tantalite composition (Nb/Ta) and the genetic type; on the other hand, Fe/Mn depends of geochemical enviroment in ore deposits formation. The Nb-Ta cassiterites contain microinclusions of columbite-tantalite, the Ti-Nb cassiterites microinclusions of ilmeno-rutile and columbite-Tantalite and the Ti-cassiterites, rutiles

Do envy and compassion pave the way to unhappiness? Social preferences and life satisfaction in a Spanish city

Mounting evidence shows that people’s self-reported life satisfaction (LS) is negatively related to income inequality. Under the interpretation that the relationship between macro-level variables and LS reflects individuals’ social preferences, this finding indicates that most people display inequality-averse preferences. We explore the relationship between self-reports on inequality aversion and LS in a citywide representative survey/experiment conducted in Spain. If self-reported well-being can be used to infer people’s social preferences, LS should correlate negatively with both “envy” and “compassion” scores (i.e., how much one suffers from disadvantageous and advantageous inequality, respectively). We find that LS relates negatively to envy but positively to compassion, which would imply that suffering from observing poorer others, paradoxically, increases well-being. Using an incentivized Dictator Game as a measure of generous behavior, we reject the hypothesis that the positive link between compassion and LS is actually driven by generosity. We discuss how these findings could indicate that the way LS is used to assess social preferences in the population should be revised

Caveolin-1 Modulates Mechanotransduction Responses to Substrate Stiffness through Actin-Dependent Control of YAP

The transcriptional regulator YAP orchestrates many cellular functions, including tissue homeostasis, organ growth control, and tumorigenesis. Mechanical stimuli are a key input to YAP activity, but the mechanisms controlling this regulation remain largely uncharacterized. We show that CAV1 positively modulates the YAP mechanoresponse to substrate stiffness through actin-cytoskeleton-dependent and Hippo-kinase-independent mechanisms. RHO activity is necessary, but not sufficient, for CAV1-dependent mechanoregulation of YAP activity. Systematic quantitative interactomic studies and image-based small interfering RNA (siRNA) screens provide evidence that this actin-dependent regulation is determined by YAP interaction with the 14-3-3 protein YWHAH. Constitutive YAP activation rescued phenotypes associated with CAV1 loss, including defective extracellular matrix (ECM) remodeling. CAV1-mediated control of YAP activity was validated in vivo in a model of pancreatitis-driven acinar-to-ductal metaplasia. We propose that this CAV1-YAP mechanotransduction system controls a significant share of cell programs linked to these two pivotal regulators, with potentially broad physiological and pathological implications. Moreno-Vicente et al. report that CAV1, a key component of PM mechanosensing caveolae, mediates adaptation to ECM rigidity by modulating YAP activity through the control of actin dynamics and phosphorylation-dependent interaction of YAP with the 14-3-3-domain protein YWHAH. Cav1-dependent YAP regulation drives two pathophysiological processes: ECM remodeling and pancreatic ADM. © 2018 The Author

Corrección de consolidación viciosa diafisaria de fémur: osteotomía en caparazón. A propósito de dos casos.

La adecuada alineación del miembro inferior es esencial para el adecuado reparto de cargas que permita una deambulación sin alteraciones. Por lo que a la hora del tratamiento de fracturas de huesos largos del miembro inferior, fundamentalmente fémur y tibia, habrá que evitar cualquier deformidad angular que a medio plazo provoque fenómenos degenerativos en las articulaciones adyacentes. Se presentan dos casos clínicos complejos, en los que se corrigieron sendas consolidaciones viciosas de fracturas diafisarias de fémur satisfactoriamente, mediante osteotomía tipo caparazón o clamshellThe lower limb alignment is essential to share correctly the bearing weight of the body to allow a suitable gait. We should take it into account when treating femoral and tibial diaphyseal fractures, in order to avoid angular deformities which could lead to degenerative changes in adjacent joints. We report two complex cases, with femoral shaft malunions corrected satisfactorily by using a clamshell osteotom

Reflection and transmission of waves in surface-disordered waveguides

The reflection and transmission amplitudes of waves in disordered multimode waveguides are studied by means of numerical simulations based on the invariant embedding equations. In particular, we analyze the influence of surface-type disorder on the behavior of the ensemble average and fluctuations of the reflection and transmission coefficients, reflectance, transmittance, and conductance. Our results show anomalous effects stemming from the combination of mode dispersion and rough surface scattering: For a given waveguide length, the larger the mode transverse momentum is, the more strongly is the mode scattered. These effects manifest themselves in the mode selectivity of the transmission coefficients, anomalous backscattering enhancement, and speckle pattern both in reflection and transmission, reflectance and transmittance, and also in the conductance and its universal fluctuations. It is shown that, in contrast to volume impurities, surface scattering in quasi-one-dimensional structures (waveguides) gives rise to the coexistence of the ballistic, diffusive, and localized regimes within the same sample.Comment: LaTeX (REVTeX), 12 pages with 14 EPS figures (epsf macro), minor change

Anderson localization in a periodic photonic lattice with a disordered boundary

We investigate experimentally the light evolution inside a two-dimensional finite periodic array of weakly- coupled optical waveguides with a disordered boundary. For a completely localized initial condition away from the surface, we find that the disordered boundary induces an asymptotic localization in the bulk, centered around the initial position of the input beam.Comment: 3 pages, 4 figure

Design and manufacture of a high-temperature PEMFC and its cooling system to power a lightweight UAV for a high altitude mission

In the present study, the optimal design of a high-temperature proton exchange membrane fuel cell (HT-PEMFC) that will be used to power an unmanned aerial vehicle (UAV) in a high altitude mission is performed. The use of PEMFCs for service ceiling above 10 km implies overcoming a number of problems caused by the harsh environmental conditions. Among them, new strategies to manage the heat generated by electrochemical reactions are needed. The maximum power required by the UAV was determined solving the aerodynamic problem, and the design of the lightweight HT-PEMFC, including its cooling system, was optimized. To perform the numerical solution of the heat transfer problem, a computational code was implemented using the EES software. The decisions adopted resulted in a 40-cells stack with an electric power above 1 kW and a weight around 3.65 kg. Besides, it is demonstrated that, for the configuration considered in the study, a passive cooling system without any additional fan system can be used to maintain the stack temperature in 160 °C

Effects of Topography and Surface Soil Cover on Erosion for Mining Reclamation: The Experimental Spoil Heap at El Machorro Mine (Central Spain)

Mining reclamation tries to reduce environmental impacts, including accelerated runoff, erosion and sediment load in the nearby fluvial networks and their ecosystems. This study compares the effects of topography and surface soil cover on erosion on man-made slopes coming from surface mining reclamation in Central Spain. Two topographic profiles, linear and concave, with two surface soil covers, subsoil and topsoil, were monitored for two hydrologic years. Sediment load, rill development and plant colonization from the four profiles were measured under field conditions. The results show that, in the case of this experiment, a thick and non-compacted topsoil cover on a linear slope yielded less sediment than carbonate colluvium or topsoil cover on a concave slope. This study also shows that vegetation establishment, which plays an important role in erosion control, depends on topography. Plant cover was more widespread and more homogeneous on linear profiles with topsoil cover. On concave slopes, plant establishment was severely limited on the steepest upper part and favoured in the bottom. This study suggests that management of topography and surface soil cover should be approached systematically, taking three outcomes into consideration: (i) topsoil can lead to a successful mining reclamation regardless of topography, (ii) created concave slopes can lead to a successful mining reclamation and (iii) topography determines the vegetation colonization pattern.The experiment was funded by a research contract between the Spanish mining company 602 CAOBAR S.A. and the Department of Geodynamics of the Complutense University of Madrid 603 (research contract numbers 234/2007, 290/2008 261/2009). The data analyses and manuscript 604 production were developed within two Research Projects, CGL2009-14508-C02-01 and 605 CGL2010-21754-C02, of the Spanish Ministry of Science and Technology and by the 606 Ecological Restoration network REMEDINAL-2 (S2009/AMB-1783).Peer reviewe