Mesoscopic Stern-Gerlach device to polarize spin currents

Spin preparation and spin detection are fundamental problems in spintronics and in several solid state proposals for quantum information processing. Here we propose the mesoscopic equivalent of an optical polarizing beam splitter (PBS). This interferometric device uses non-dispersive phases (Aharonov-Bohm and Rashba) in order to separate spin up and spin down carriers into distinct outputs and thus it is analogous to a Stern-Gerlach apparatus. It can be used both as a spin preparation device and as a spin measuring device by converting spin into charge (orbital) degrees of freedom. An important feature of the proposed spin polarizer is that no ferromagnetic contacts are used.Comment: Updated to the published versio

Revisiting the genus Photobacterium: taxonomy, ecology and pathogenesis

The genus Photobacterium, one of the eight genera included in the family Vibrionaceae, contains 27 species with valid names and it has received attention because of the bioluminescence and pathogenesis mechanisms that some of its species exhibit. However, the taxonomy and phylogeny of this genus are not completely elucidated; for example, P. logei and P. fischeri are now considered members of the genus Aliivibrio, and previously were included in the genus Vibrio. In addition, P. damselae subsp. piscicida was formed as a new combination for former Vibrio damsela and Pasteurella piscicida. Moreover, P. damselae subsp. damselae is an earlier heterotypic synonym of P. histaminum. To avoid these incovenences draft and complete genomic sequences of members of Photobacterium are increasingly becoming available and their use is now routine for many research laboratories to address diverse goals: species delineation with overall genomic indexes, phylogenetic analyses, comparative genomics, and phenotypic inference. The habitats and isolation source of the Photobacterium species include seawater, sea sediments, saline lake waters, and a variety of marine organisms with which the photobacteria establish different relationships, from symbiosis to pathogenic interactions. Several species of this genus contain bioluminescent strains in symbiosis with marine fish and cephalopods; in addition, other species enhance its growth at pressures above 1 atmosphere, by means of several high-pressure adaptation mechanisms and for this, they may be considered as piezophilic (former barophilic) bacteria. Until now, only P. jeanii, P. rosenbergii, P. sanctipauli, and the two subspecies of P. damselae have been reported as responsible agents of several pathologies on animal hosts, such as corals, sponges, fish and homeothermic animals. In this review we have revised and updated the taxonomy, ecology and pathogenicity of several members of this genus. [Int Microbiol 20(1): 1-10 (2017)]Keywords: Photobacterium · taxonomy · symbiosis · pathogenesis · virulence factor

Detección y cuantificación del virus de la enfermedad de linfocistis mediante ensayo ICC-RT-PCR (integrated cell culture-RT-PCR)

La enfermedad de linfocistis es la enfermedad de etiología viral más frecuentemente detectada en la acuicultura marina europea, siendo la principal patología de origen vírico descrita en doradas cultivadas. El agente etiológico de esta enfermedad es el virus de la enfermedad de linfocistis (LCDV), miembro del género Lymphocystivirus, perteneciente a la familia Iridoviridae. Se han desarrollado diversos protocolos de PCR y PCR a tiempo real que permiten la detección y cuantificación del LCDV en diversas muestras, si bien no aportan ninguna indicación de la infectividad de los virus detectados. La detección de partículas víricas infectivas requiere la utilización de cultivos celulares, pero en el caso del LCDV la observación de efectos citopáticos (CPE) es difícil y a menudo está sujeta a subjetividad, especialmente en muestras con baja carga vírica. Por este motivo, en el presente trabajo se ha desarrollado un ensayo de ICC-RT-PCR (Integrated Cell Culture-RT-PCR) que permite la detección de partículas infectivas del LCDV. Este ensayo se ha aplicado en combinación con el método del número más probable (NMP) para la determinación del título infectivo en cultivos celulares. El protocolo de ICC-RT-PCR desarrollado permitió la detección de mRNA viral a partir de células SAF-1 inoculadas con un título infectivo de LCDV de 0,1 TCID50/ml, procesadas a los 5 d p.i, mientras que el límite de detección mediante observación de CPE fue de 10 TCID50/ml a 14 d p.i. La sensibilidad de la técnica he permitido la detección de partículas infectivas del LCDV en ejemplares de dorada asintomáticos, donde no se observaron CPE en cultivos celulares inoculados en paralelo y mantenidos hasta 14 d p.i. Este protocolo también se ha aplicado para la determinación del título infectivo de diferentes aislados víricos obtenidos a partir de peces enfermos, reduciéndose de forma considerable el tiempo necesario para realizar la titulación en comparación con el método de la dosis infectiva 50% en cultivos celulares (TCID50) (5 d versus 14-21 d, respectivamente). Así mismo, se han titulado stocks víricos obtenidos en cultivos celulares, donde la carga vírica es inferior al límite de detección del ensayo de observación de CPE. En conclusión, el protocolo de ICC-RT-PCR desarrollado es una técnica sensible, rápida y útil para la detección y cuantificación de LCDV infectivos, lo que la convierte en una herramienta adecuada para el estudio de esta patología viral.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

A theory of ferromagnetism in planar heterostructures of (Mn,III)-V semiconductors

A density functional theory of ferromagnetism in heterostructures of compound semiconductors doped with magnetic impurities is presented. The variable functions in the density functional theory are the charge and spin densities of the itinerant carriers and the charge and localized spins of the impurities. The theory is applied to study the Curie temperature of planar heterostructures of III-V semiconductors doped with manganese atoms. The mean-field, virtual-crystal and effective-mass approximations are adopted to calculate the electronic structure, including the spin-orbit interaction, and the magnetic susceptibilities, leading to the Curie temperature. By means of these results, we attempt to understand the observed dependence of the Curie temperature of planar $\delta$-doped ferromagnetic structures on variation of their properties. We predict a large increase of the Curie Temperature by additional confinement of the holes in a $\delta$-doped layer of Mn by a quantum well.Comment: 8 pages, 7 figure

Assessing the economic suitability of aeration and the influence of bed heating on constructed wetlands treatment efficiency and life-span

Intensive constructed wetlands including forced aeration and heating were studied to improve treatment efficiency and prevent clogging. The experiments were carried out in a pilot plant (0.4 m2) treating urban wastewater with an organic loading rate of 40-60 gCOD/m2∙d. Continuous and intermittent aeration was performed on 8% of the wetland surface, leading to different dissolved oxygen concentrations within the wetlands (from 0.2 to 5 mgO2/L). Continuous forced aeration increased organic matter (COD) and ammonium nitrogen removal by 56% and 69%, respectively. Improvements in 33 wastewater treatment caused by forced aeration can result into reduction of the surface area. This work demonstrated that for the studied configuration the cost of the power consumption of the continuous aeration was largely covered by the reduction of the wetlands surface. Even if the heating of 8% of the wetland surface at 21°C had no effects on treatment performances, positive results showed that solids accumulation rate within the granular medium, which is closely related to the development of clogging. It has been demonstrated that heating for 10 days per year during 20 year period would delay the equivalent of 1 year of solids accumulation

Co-occurrence of viral and bacterial pathogens in disease outbreaks affecting newly cultured sparid fish

Several microbial disease outbreaks in farm stocks of newly cultured sparid fish species, such as common seabream, redbanded seabream, and white seabream, were recorded from 2004 to 2006. This study describes the isolation and characterization of the potential causative agents, either bacteria or viruses, of these outbreaks. The isolated bacterial strains were characterized according to traditional taxonomical analyses and sequencing of a 16S rDNA fragment. Most bacteria were identified as Vibrio spp. and Photobacterium damselae subsp. damselae. The development of cytopathic effects (CPE) on different fish cell lines, the application of specific nested-PCR tests for infectious pancreatic necrosis virus (IPNV), viral nervous necrosis virus (VNNV) and viral hemorrhagic septicemia virus (VHSV), and subsequent sequence analyses were used for virus detection and identification. VNNV, related to the striped jack neural necrosis virus (SJNNV) genotype, and VHSV, related to the genotype Ia, were the only viruses detected. VNNV was isolated from the three fish species under study in five different outbreaks, whereas VHSV was isolated from common seabream and white seabream during two of these outbreaks. IPNV was not detected in any case. [Int Microbiol 2007; 10(3):193-199

Tax Collectors for Fair Admissions: Advancing State-Level Tax Incentives to Curb Legacy Admissions

Part I of this Note will contextualize the practice of legacy admissions, describe its inherent unfairness and deleterious effects, and explain why—notwithstanding those concerns—some universities still employ the practice in their admissions processes. With that background, Part II of this Note will explain why fiscal incentives are the most appropriate mechanism to disincentivize legacy admissions practices. Part III will then evaluate the flawed federal fiscal proposals to curb legacy admissions, and Part IV will argue that state-level solutions should be preferred to federal ones to respect the values of federalism and promote the most narrowly-crafted, individualized, and state-specific solutions. This abstract has been taken from the author\u27s introduction

The effectiveness of neuromuscular warm-up strategies, that require no additional equipment, for preventing lower limb injuries during sports participation: a systematic review

PMCID: PMC3408383The electronic version of this article is the complete one and can be found online at: http://www.biomedcentral.com/1741-7015/10/75. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited

Dilution and confirmation of probability judgments based on nondiagnostic evidence

Previous research has shown that probability judgments based on a mix of diagnostic and nondiagnostic information are less extreme than judgments based on the diagnostic information alone. Results of the present experiments suggest that this dilution effect holds only under a limited set of conditions. When judgments based on a mix of diagnostic and nondiagnostic information are compared with separately elicited judgments based on the diagnostic information alone, the dilution effect is consistently observed. When judgments based on the diagnostic evidence are revised in light of additional, nondiagnostic evidence, by contrast, the dilution effect is eliminated or even reversed (yielding a confirmation effect) depending on the type of nondiagnostic evidence under evaluation