Spin filtering in nanowire directional coupler

The spin transport characteristics of a nanowire directional electronic coupler have been evaluated theoretically via a transfer matrix approach. The application of a gate field in the region of mixing allows for control of spin current through the different leads of the coupler via the Rashba spin-orbit interaction. The combination of spin-orbit interaction and applied gate voltages on different legs of the coupler give rise to a controllable modulation of the spin polarization. Both structural factors and field strength tuning lead to a rich phenomenology that could be exploited in spintronic devices.Comment: 9 pages, 4 figure

Tuning hole mobility in InP nanowires

Transport properties of holes in InP nanowires were calculated considering electron-phonon interaction via deformation potentials, the effect of temperature and strain fields. Using molecular dynamics, we simulate nanowire structures, LO-phonon energy renormalization and lifetime. The valence band ground state changes between light- and heavy-hole character, as the strain fields and the nanowire size are changed. Drastic changes in the mobility arise with the onset of resonance between the LO-phonons and the separation between valence subbands.Comment: 4 pages, 4 figure

Pluviometric variations as subsidiary information for agricultural planning in the Amazon.

The area of interest for this study lies in the Western part of the Amazon. Monthly and annual meteorological data from 12 places were used, with daily data from eight rain gauges and daily rainfall intensity records. Data were presented from tests of water infiltration into the soil performed in the region. The results showed that the Northwest part of the region was the rainiest, attaining annual means of 3,333 mm at Iauaretê. In the Southern part, beginning at 5°S, the mean values reached 1,952 mm, at Rio Branco. Mean annual rainfalls ranged from 2,500 mm to 2,200 mm, in the region. The lowest pluvial total was 1,365 mm, which occurred at Parintins in 1983, and may be associated to the effects of a strong El Niño (82-83). In years when La Niña was strong, rainfalls were above the average and when El Niño was strong, they were below the average. The rainiest period was from December to April with means above 160 mm and the least rainy was from May to September, August being the month with the lowest rainfall. Close to Humaitá, annual rainfalls were less than 2,000 mm

Sustentabilidade e inovação tecnológica em sistemas produtivos familiares integrados com palma de óleo no Estado do Pará.

Objetivou-se analisar os aspectos organizacionais, econômicos, ambientais e tecnológicos em sistemas produtivos familiares integrados com palma de óleo no Estado do Pará. Os levantamentos de dados foram através de entrevistas semi estruturadas para o público de agricultores familiares fornecedores de cacho de fruto fresco (CFF) para agroindústrias de óleo de palma nos municípios de Moju, Tailândia, Acará e São Domingos do Capim. Nesse sentido foram identificados que os aspectos renda e uso de tecnologias produtivas são favoráveis para este segmento da agricultura familiar nesta parte da Amazônia

Spin-polarization in quantum wires: Influence of Dresselhaus spin-orbit interaction and cross-section effects

We examine the effects of the full Dresselhaus spin-orbit coupling on laterally confined quantum wire states. An analysis of the relative contributions due to linear, quadratic, and cubic Dresselhaus spin-orbit terms on the energy levels, spin splitting, and spin polarization has been carried out. The effects of wire cross-sectional geometry shapes on the electronic structure are explored. In particular we compared the results of semicylindrical and cylindrical confinements and have found important differences between the spin degeneracy of the ground-state level and the spin-polarization dependence on sign inversion of the free linear momentum quantum number along the wire axis. Different from other symmetries, in both cases here considered, the stronger spin-splitting effects come from the quadratic Dresselhaus term. We report ideal conditions for realization of spin-field filter devices based on symmetry properties of the spin splitting of the ground state in semicylindrical quantum wires

Perception of olive oils sensory defects using a potentiometric taste device

The capability of perceiving olive oils sensory defects and intensities plays a key role on olive oils quality grade classification since olive oils can only be classified as extra-virgin if no defect can be perceived by a human trained sensory panel. Otherwise, olive oils may be classified as virgin or lampante depending on the median intensity of the defect predominantly perceived and on the physicochemical levels. However, sensory analysis is time-consuming and requires an official sensory panel, which can only evaluate a low number of samples per day. In this work, the potential use of an electronic tongue as a taste sensor device to identify the defect predominantly perceived in olive oils was evaluated. The potentiometric profiles recorded showed that intra- and inter-day signal drifts could be neglected (i.e., relative standard deviations lower than 25%), being not statistically significant the effect of the analysis day on the overall recorded E-tongue sensor fingerprints (P-value=0.5715, for multivariate analysis of variance using Pillai's trace test), which significantly differ according to the olive oils sensory defect (P-value=0.0084, for multivariate analysis of variance using Pillai's trace test). Thus, a linear discriminant model based on 19 potentiometric signal sensors, selected by the simulated annealing algorithm, could be established to correctly predict the olive oil main sensory defect (fusty, rancid, wet-wood or winey-vinegary) with average sensitivity of 75±3% and specificity of 73±4% (repeated K-fold cross-validation variant: 4 folds×10 repeats). Similarly, a linear discriminant model, based on 24 selected sensors, correctly classified 92±3% of the olive oils as virgin or lampante, being an average specificity of 93±3% achieved. The overall satisfactory predictive performances strengthen the feasibility of the developed taste sensor device as a complementary methodology for olive oils defects analysis and subsequent quality grade classification. Furthermore, the capability of identifying the type of sensory defect of an olive oil may allow establishing helpful insights regarding bad practices of olives or olive oils production, harvesting, transport and storage.This work was financially supported by Project POCI-01–0145FEDER-006984 – Associate Laboratory LSRE-LCM, Project UID/QUI/ 00616/2013 – CQ-VR, and UID/AGR/00690/2013 – CIMO all funded by FEDER - Fundo Europeu de Desenvolvimento Regional through COMPETE2020 - Programa Operacional Competitividade e Internacionalização (POCI) – and by national funds through FCT Fundação para a Ciência e a Tecnologia, Portugal. Strategic funding of UID/BIO/04469/2013 unit is also acknowledged. Nuno Rodrigues thanks FCT, POPH-QREN and FSE for the Ph.D. Grant (SFRH/BD/ 104038/2014).info:eu-repo/semantics/publishedVersio

WT1 and its transcriptional cofactor BASP1 redirect the differentiation pathway of an established blood cell line

The Wilms' tumour suppressor WT1 (Wilms' tumour 1) is a transcriptional regulator that plays a central role in organogenesis, and is mutated or aberrantly expressed in several childhood and adult malignancies. We previously identified BASP1 (brain acid-soluble protein 1) as a WT1 cofactor that suppresses the transcriptional activation function of WT1. In the present study we have analysed the dynamic between WT1 and BASP1 in the regulation of gene expression in myelogenous leukaemia K562 cells. Our findings reveal that BASP1 is a significant regulator of WT1 that is recruited to WT1-binding sites and suppresses WT1-mediated transcriptional activation at several WT1 target genes. We find that WT1 and BASP1 can divert the differentiation programme of K562 cells to a non-blood cell type following induction by the phorbol ester PMA. WT1 and BASP1 co-operate to induce the differentiation of K562 cells to a neuronal-like morphology that exhibits extensive arborization, and the expression of several genes involved in neurite outgrowth and synapse formation. Functional analysis revealed the relevance of the transcriptional reprogramming and morphological changes, in that the cells elicited a response to the neurotransmitter ATP. Taken together, the results of the present study reveal that WT1 and BASP1 can divert the lineage potential of an established blood cell line towards a cell with neuronal characteristics