Single-parameter spin-pumping in driven metallic rings with spin-orbit coupling

We consider the generation of a pure spin-current at zero bias voltage with a single time-dependent potential. To such end we study a device made of a mesoscopic ring connected to electrodes and clarify the interplay between a magnetic flux, spin-orbit coupling, and non-adiabatic driving in the production of a spin and electrical current. By using Floquet theory, we show that the generated spin to charge current ratio can be controlled by tuning the spin-orbit coupling.publishedVersionFil: Ramos Andrade, Juan Pablo. Universidad Católica del Norte. Departamento de Física; Chile.Fil: Foa Torres, Luis Eduardo Francisco. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentina.Fil: Foa Torres, Luis Eduardo Francisco. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Física Enrique Gaviola; Argentina.Fil: Orellana, P. A. Universidad Técnica Federico Santa María. Departamento de Física; Chile.Fil: Apel, Víctor Marcelo. Universidad Católica del Norte. Departamento de Física; Chile.Física de los Materiales Condensado

ADRENALECTOMÍA TRANSPERITONEAL LAPAROSCÓPICA: EXPERIENCIA

Arch Esp Urol. 2006 Nov;59(9):893-7. [Transperitoneal laparoscopic adrenalectomy: initial experience] [Article in Spanish] Palacios A, Lima E, Massó P, Versos R, Autorino R, Ramos M, Soares J, Marcelo F. Servicio de Urología, Hospital Geral de Santo António, Porto, Portugal. [email protected] Abstract OBJECTIVES: Since the first published report in 1992, laparoscopic adrenalectomy has been widespread and it is now accepted as the standard treatment option in most of benign diseases of the adrenal gland. Aim of the present study is to describe our initial experience with laparoscopic adrenalectomy. METHODS: Between May 2001 and December 2005, 15 patients were submitted to laparoscopic adrenalectomy for benign diseases of the adrenal gland. We analyzed patients characteristics (sex, age, initial diagnosis), operative and perioperative results (operative time, blood loss, time to first oral intake) and complications. RESULTS: Mean operative time was 143 minutes. Blood loss was minimal. Mean hospital stay was 90 hours. There was no need for open conversion and complication rate was low. CONCLUSIONS: Laparoscopic surgery of the adrenal gland is a safe and effective option which offers quality of life benefits to the patients. PMID: 17190212 [PubMed - indexed for MEDLIN

Nonequilibrium Precursor Model for the Onset of Percolation in a Two-Phase System

Using a Boltzmann equation, we investigate the nonequilibrium dynamics of nonperturbative fluctuations within the context of Ginzburg-Landau models. As an illustration, we examine how a two-phase system initially prepared in a homogeneous, low-temperature phase becomes populated by precursors of the opposite phase as the temperature is increased. We compute the critical value of the order parameter for the onset of percolation, which signals the breakdown of the conventional dilute gas approximation.Comment: 4 pages, 4 eps figures (uses epsf), Revtex. Replaced with version in press Physical Review

Dry Matter Yield of Promising \u3cem\u3ePanicum maximum\u3c/em\u3e Genotypes in Response to Phosphorus and Liming on Brazilian Savannah

Soil fertility of the Brazilian savannah Cerrado is naturally poor. Extensive areas of pastures located in the central part of territory are cultivated with Brachiaria grasses which are less demanding for soil nutrients and lime (Rao et al. 1998). On the other hand, Panicum maximum cultivars such as the high yielding Mombaça grass recommended to intensive beef and dairy cattle systems (Euclides et al. 2008), must be seeded with a higher amount of fertilizer, especially phosphorus (P). Consequently there is an effort for selection of P. maximum genotypes with low P demand and high responsiveness. The objective of this study was to evaluate dry matter yield of genotypes of P. maximum in response to doses of P and lime in the Brazilian Cerrado

BRS Sarandi: A New Andropogon Gayanus Cultivar for Tropical Pastures

BRS Sarandi is adapted to low and medium fertility soils. It has a medium-high height, with a semi-erect growth habit and a high total number of tillers. The annual productivity of dry matter is 11 t ha-1, concentrated in the rainy season (90%). Of the total DM produced, 60% are leaves. The levels of crude protein (CP), in vitro dry matter digestibility (IVDMD), neutral detergent fiber (NDF) and acid detergent fiber (ADF) are, on average, 8.7, 56.5, 66.7 and 38.2%, respectively. . The average daily weight gain was 0.7 kg/head/day, the gain per was and 1.7 kg ha-1 day with no supplementation except for mineral salt. The weight gain per area (AG) reached 15 @/ha/year with an average stocking rate of 2.5 AU. BRS Sarandi was registered in the Brazilian Cultivar Registry (Registro Nacional de Cultivares - RNC/MAPA) and is protected in the National Cultivar Protection System (Sistema Nacional de Proteção de Cultivares - SNPC/MAPA)

Performance of Nelore Cattle on \u3cem\u3ePanicum maximum\u3c/em\u3e Pastures in the Brazilian Cerrado

With the increased demand for meat products, associated with environmental concerns due to global climatic and land use changes, the need to efficiently use pasture and forage resources will increase (Boval and Dixon 2012). Efforts to breed and release new forage cultivars must incorporate these concerns, ensuring that introduced material is of high quality, especially under grazing (Euclides et al. 2008). In this study, we aimed to evaluate the average daily weight gain and stocking rate of Nelore beef cattle grazing new genotypes of Panicum maximum during the rainy season in the Brazilian Cerrado

Bottlenose Dolphins and Antillean Manatees Respond to Small Multi-Rotor Unmanned Aerial Systems

Unmanned aerial systems (UASs) are powerful tools for research and monitoring of wildlife. However, the effects of these systems on most marine mammals are largely unknown, preventing the establishment of guidelines that will minimize animal disturbance. In this study, we evaluated the behavioral responses of coastal bottlenose dolphins (Tursiops truncatus) and Antillean manatees (Trichechus manatus manatus) to small multi-rotor UAS flight. From 2015 to 2017, we piloted 211 flights using DJI quadcopters (Phantom II Vision +, 3 Professional and 4) to approach and follow animals over shallow-water habitats in Belize. The quadcopters were equipped with high-resolution cameras to observe dolphins during 138 of these flights, and manatees during 73 flights. Aerial video observations of animal behavior were coded and paired with flight data to determine whether animal activity and/or the UAS's flight patterns caused behavioral changes in exposed animals. Dolphins responded to UAS flight at altitudes of 11–30 m and responded primarily when they were alone or in small groups. Single dolphins and one pair responded to the UAS by orienting upward and turning toward the aircraft to observe it, before quickly returning to their pre-response activity. A higher number of manatees responded to the UAS, exhibiting strong disturbance in response to the aircraft from 6 to 104 m. Manatees changed their behavior by fleeing the area and sometimes this elicited the same response in nearby animals. If pursued post-response, manatees repeatedly responded to overhead flight by evading the aircraft's path. These findings suggest that the invasiveness of UAS varies across individuals, species, and taxa. We conclude that careful exploratory research is needed to determine the impact of multi-rotor UAS flight on diverse species, and to develop best practices aimed at reducing the disturbance to wildlife that may result from their use

Citrus leprosis virus C infection results in hypersensitive-like response, suppression of the JA/ET plant defense pathway and promotion of the colonization of its mite vector

Leprosis is a serious disease of citrus caused by Citrus leprosis virus C (CiLV-C, genus Cilevirus) whose transmission is mediated by false spider mites of the genus Brevipalpus. CiLV-C infection does not systemically spread in any of its known host plants, thus remaining restricted to local lesions around the feeding sites of viruliferous mites. To get insight into this unusual pathosystem, we evaluated the expression profiles of genes involved in defense mechanisms of Arabidopsis thaliana and Citrus sinensis upon infestation with non-viruliferous and viruliferous mites by using reverse-transcription qPCR. These results were analyzed together with the production of reactive oxygen species (ROS) and the appearance of dead cells as assessed by histochemical assays. After interaction with non-viruliferous mites, plants locally accumulated ROS and triggered the salicylic acid (SA) and jasmonate/ethylene (JA/ET) pathways. ERE branch of the JA/ET pathways was highly activated. In contrast, JA pathway genes were markedly suppressed upon the CiLV-C infection mediated by viruliferous mites. Viral infection also intensified the ROS burst and cell death, and enhanced the expression of genes involved in the RNA silencing mechanism and SA pathway. After 13 days of infestation of two sets of Arabidopsis plants with non-viruliferous and viruliferous mites, the number of mites in the CiLV-C infected Arabidopsis plants was significantly higher than in those infested with the non-viruliferous ones. Oviposition of the viruliferous mites occurred preferentially in the CiLV-C infected leaves. Based on these results, we postulated the first model of plant/Brevipalpus mite/cilevirus interaction in which cells surrounding the feeding sites of viruliferous mites typify the outcome of a hypersensitive-like response, whereas viral infection induces changes in the behavior of its vector7CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP573848/08-4; 375843/2012-42012/18771- 0; 2014/00366-8; 2008/57909-2; 2014/08458-

Optimización de la producción de poli(β-hidroxibutirato) a partir de glicerol

En este trabajo se ha realizado el diseño preliminar de una planta de producción de poli(β-hidroxibutirato), PHB, mediante el empleo de microorganismos y a partir de glicerol como materia prima. El proceso consta de tres etapas: purificación de la materia prima, donde la corriente de glicerol, subproducto en la producción de biodiesel, se despoja del metanol que pudiese contener; fermentación, donde se produce PHB a partir de Cupriavidus necátor y por último, extracción del producto, donde se produce la lisis celular y se logra la separación y purificación del biopolímero.Sociedad Argentina de Informática e Investigación Operativ