Magnetization Switching in Nanowires: Monte Carlo Study with Fast Fourier Transformation for Dipolar Fields

For the investigations of thermally activated magnetization reversal in systems of classical magnetic moments numerical methods are desirable. We present numerical studies which base on time quantified Monte Carlo methods where the long-range dipole-dipole interaction is calculated with the aid of fast Fourier transformation. As an example, we study models for ferromagnetic nanowires comparing our numerical results for the characteristic time of the reversal process also with numerical data from Langevin dynamics simulations where the fast Fourier transformation method is well established. Depending on the system geometry different reversal mechanism occur like coherent rotation, nucleation, and curling.Comment: 7 pages, 5 figures, submitted to J. Magn. Magn. Ma

Techniques for Achieving High Isolation in RF Domain for Simultaneous Transmit and Receive

With the growth of wireless data traffic, additional spectrum is required to meet consumer demands. Consequently, innovative approaches are needed for efficient management of the available limited spectrum. To double the achievable spectral efficiency, a transceiver can be designed to receive and transmit signals simultaneously (STAR) across the same frequency band. However, due to the coupling of the high power transmitted signal into the collocated receiver, the receiver\u27s performance is degraded. For successful STAR realization, the coupled high-power transmit (Tx) signal should be suppressed by 100-120 dB over the entire operational bandwidth. So far, most STAR implementations are narrowband, and not useful for ultra wideband (UWB) communications. In this paper, we present a review of novel approaches employed to achieve improved cancellation across wide bandwidths in RF and propagation domains. Both single and multi-antenna systems are considered. Measurements show an average cancellation of 50 dB using two stages of RF signal cancellation

Relações entre atributos microbiológicos e bioquímicos do solo com a produtividade de soja em sistema de plantio direto.

O sistema de plantio direto (SPD) permite maior conservação do solo e da água, melhoria da fertilidade do solo e da atividade biológica, garantindo maior sustentabilidade ao sistema de produção. O objetivo desse trabalho foi identificar atributos microbiológicos e bioquímicos do solo que auxiliem a explicar níveis de produtividade de soja cultivada sob SPD, por meio de métodos multivariados. As amostragens foram realizadas em janeiro e setembro de 2011 em Ponta Grossa, PR, em áreas de cultivo comercial de grãos. Foram coletadas 4 amostras compostas de solo, na profundidade 0-10 cm, em 6 áreas agrícolas com histórico de diferentes níveis de produtividades de grãos. Foram avaliadas a respiração basal (RB), biomassa microbiana de carbono (BMC) e nitrogênio (BMN), atividade das enzimas desidrogenase, celulase, glutaminase e fosfatase ácida. Calculou-se o quociente metabólico (qCO2) pela razão entre RB e BMC. Os dados foram submetidos à análise de componentes principais (ACP) e análise canônica discriminante (ACD). Na ACP, os bioindicadores avaliados foram relacionados principalmente às áreas de alta produtividade de grãos. A ACD evidenciou a capacidade da BMC e da atividade enzimática em discriminar as áreas de acordo com os níveis de produtividade. Conclui-se que os bioindicadores BMC e atividade das enzimas celulase, glutaminase e fosfatase ácida, podem ser usados para auxiliar a explicar níveis de produtividade de soja em áreas de produção agrícola comercial.Fertbio

How long can you hold the filler:Maintenance and retrieval

This study attempts to reveal the mechanisms behind the online formation of Wh-Filler-Gap Dependencies (WhFGD). Specifically, we aim to uncover the way in which maintenance and retrieval work in WhFGD processing, by paying special attention to the information that is retrieved when the gap is recognized. We use the agreement attraction phenomenon (Wagers, M. W., Lau, E. F., & Phillips, C. (2009). Agreement attraction in comprehension: Representations and processes. Journal of Memory and Language, 61(2), 206-237) as a probe. The first and second experiments examined the type of information that is maintained and how maintenance is motivated, investigating the retrieved information at the gap for reactivated fillers and definite NPs. The third experiment examined the role of the retrieval, comparing reactivated and active fillers. We contend that the information being accessed reflects the extent to which the filler is maintained, where the reader is able to access fine-grained information including category information as well as a representation of both the head and the modifier at the verb

Carbono orgânico e atributos microbiológicos em solo agrícola com diferentes níveis de produtividade de soja em sistema de plantio direto.

Atributos microbiológicos e bioquímicos do solo são geralmente negligenciados ao se relacionar a fertilidade do solo e a produtividade das culturas, em que o carbono orgânico (C) apresenta papel chave. O objetivo deste trabalho foi avaliar alguns bioindicadores de qualidade de solo e relacioná-los com o teor de C do solo em áreas de produção comercial com diferentes níveis de produtividade de soja sob sistema de plantio direto. Amostras compostas de solo foram obtidas na profundidade 0-10 cm, em 6 áreas agrícolas em Ponta Grossa, PR. Os dados foram submetidos à análise de correlação de Pearson e regressão múltipla. A regressão múltipla mostrou que a produtividade é influenciada principalmente pelo teor de C orgânico no solo, e a correlação simples de Pearson mostrou-se significativa entre o C orgânico e a biomassa microbiana de carbono (BMC), biomassa microbiana de nitrogênio (BMN), capacidade de troca de cátions (CTC) e atividades enzimáticas. Conclui-se que há uma relação entre a produtividade de grãos de soja e a atividade microbiana no solo, em que o C orgânico apresenta papel chave.Fertbio

Left ventricular echocardiographic and histologic changes: Impact of chronic unloading by an implantable ventricular assist device

AbstractObjectives. We studied the effects of chronic left ventricular unloading by a ventricular assist device and assessed left ventricular morphologic and histologic changes.Background. The implantable left ventricular assist device has been effective as a “bridge” to cardiac transplantation. Although there are reports documenting its circulatory support, little is known about the effects of chronic left ventricular unloading on the heart itself.Methods. We performed intraoperative transesophageal echocardiography at the insertion and explantation of a HeartMate left ventricular assist device in 19 patients with end-stage heart failure. They were supported by the assist device for 3 to 153 days (mean [±SD] 68±33). Measurements were taken retrospectively to obtain left atrial and ventricular diameters and interventricular septal and posterior wall thicknesses. Histologic examinations were made from the left ventricular myocardial specimens of 15 patients at the times of insertion and explantation for heart transplantation. Insertion and explantation specimens were compared qualitatively (0 to 3 scale) for wavy fibers, contraction band necrosis and fibrosis, with quantitative measurement of minimal myocyte diameter across the nucleus.Results. Left atrial and left ventricular diastolic and systolic diameters decreased immediately after insertion of the left ventricular assist device (from 46 to 35, 63 to 41 and 59 to 36 mm, respectively, all p < 0.001). Left ventricular wall thickness increased from 10 to 14 mm (p < 0.001) for the interventricular septum and from 10 to 13 mm for the posterior wall (p < 0.001). No echocardiographic measurements showed significant subsequent changes at the chronic stage. Myocardial histologic findings demonstrated a reduction in myocyte damage (from 1.9 to 0.5, p < 0.001, for wavy fiber and from 1.3 to 0.2, p < 0.01, for contraction band necrosis) and an increase in fibrosis (from 1.3 to 1.9, p < 0.05), but without significant change in myocyte diameter (from 15.6 to 16.8 μm, p = 0.065).Conclusions.Left ventricular unloading with the implantable assist device induces an immediate increase in wall thickness, consistent with the reduction in chamber size, thereby decreasing wall stress. Chronic unloading allows myocardial healing and fibrosis without evidence for ongoing myocyte damage or atrophy. Left ventricular assist device insertion may have a role in “resting” the ventricle for selected patients with heart failure

Localization of a 64-kDa phosphoprotein in the lumen between the outer and inner envelopes of pea chloroplasts

The identification and localization of a marker protein for the intermembrane space between the outer and inner chloroplast envelopes is described. This 64-kDa protein is very rapidly labeled by [γ-32P]ATP at very low (30 nM) ATP concentrations and the phosphoryl group exhibits a high turnover rate. It was possible to establish the presence of the 64-kDa protein in this plastid compartment by using different chloroplast envelope separation and isolation techniques. In addition comparison of labeling kinetics by intact and hypotonically lysed pea chloroplasts support the localization of the 64-kDa protein in the intermembrane space. The 64-kDa protein was present and could be labeled in mixed envelope membranes isolated from hypotonically lysed plastids. Mixed envelope membranes incorporated high amounts of 32P from [γ-32P]ATP into the 64-kDa protein, whereas separated outer and inner envelope membranes did not show significant phosphorylation of this protein. Water/Triton X-114 phase partitioning demonstrated that the 64-kDa protein is a hydrophilic polypeptide. These findings suggest that the 64-kDa protein is a soluble protein trapped in the space between the inner and outer envelope membranes. After sonication of mixed envelope membranes, the 64-kDa protein was no longer present in the membrane fraction, but could be found in the supernatant after a 110000 × g centrifugation

Higher order QCD corrections to charged-lepton deep-inelastic scattering and global fits of parton distributions

We study the perturbative QCD corrections to heavy-quark structure functions of charged-lepton deep-inelastic scattering and their impact on global fits of parton distributions. We include the logarithmically enhanced terms near threshold due to soft gluon resummation in the QCD corrections at next-to-next-to-leading order. We demonstrate that this approximation is sufficient to describe the available HERA data in most parts of the kinematic region. The threshold-enhanced next-to-next-to-leading order corrections improve the agreement between predictions based on global fits of the parton distribution functions and the HERA collider data even in the small-x region.Comment: 11 pages, 6 figures, latex, extended journal versio