Magnetoresistance of a semiconducting magnetic wire with domain wall

We investigate theoretically the influence of the spin-orbit interaction of Rashba type on the magnetoresistance of a semiconducting ferromagnetic nanostructure with a laterally constrained domain wall. The domain wall is assumed sharp (on the scale of the Fermi wave length of the charge carriers). It is shown that the magnetoresistance in such a case can be considerably large, which is in a qualitative agreement with recent experimental observations. It is also shown that spin-orbit interaction may result in an increase of the magnetoresistance. The role of localization corrections is also briefly discussed.Comment: 5 pages, 2 figure

Protective effect of budesonide/formoterol compared with formoterol, salbutamol and placebo on repeated provocations with inhaled AMP in patients with asthma: a randomised, double-blind, cross-over study

<p>Abstract</p> <p>Background</p> <p>The budesonide/formoterol combination is successfully used for fast relief of asthma symptoms in addition to its use as maintenance therapy. The temporarily increased corticosteroid dose during increasing inhaler use for symptom relief is likely to suppress any temporary increase in airway inflammation and may mitigate or prevent asthma exacerbations. The relative contribution of the budesonide and formoterol components to the improved asthma control is unclear.</p> <p>Methods</p> <p>The acute protective effect of inhaled budesonide was tested in a model of temporarily increased airway inflammation with repeated indirect airway challenges, mimicking an acute asthma exacerbation. A randomised, double-blind, cross-over study design was used. Asthmatic patients (n = 17, mean FEV₁95% of predicted) who previously demonstrated a ≥30% fall in forced expiratory volume in 1 second (FEV₁) after inhaling adenosine 5'-monophosphate (AMP), were challenged on four consecutive test days, with the same dose of AMP (at 09:00, 12:00 and 16:00 hours). Within 1 minute of the maximal AMP-induced bronchoconstriction at 09:00 hours, the patients inhaled one dose of either budesonide/formoterol (160/4.5 μg), formoterol (4.5 μg), salbutamol (2 × 100 μg) or placebo. The protective effects of the randomised treatments were assessed by serial lung function measurements over the test day.</p> <p>Results</p> <p>In the AMP provocations at 3 and 7 hours after inhalation, the budesonide/formoterol combination provided a greater protective effect against AMP-induced bronchoconstriction compared with formoterol alone, salbutamol and placebo. In addition all three active treatments significantly increased FEV₁within 3 minutes of administration, at a time when inhaled AMP had induced the 30% fall in FEV₁.</p> <p>Conclusions</p> <p>A single dose of budesonide/formoterol provided a greater protective effect against inhaled AMP-induced bronchoconstriction than formoterol alone, both at 3 and at 7 hours after inhalation. The acute protection against subsequent bronchoconstrictor stimuli such as inhaled AMP and the rapid reversal of airway obstruction supports the use of budesonide/formoterol for both relief and prevention in the treatment of asthma.</p> <p>Trial Registration</p> <p>ClinicalTrials.gov number NCT00272753</p

Modelling Cyclic Walking in Femurs With Metastatic Lesions:Femur-Specific Accumulation of Plasticity

Introduction Clinical fracture risk assessment in metastatic bone disease is extremely difficult, but subject-specific finite element (FE) modelling may improve these assessments in the future [Derikx, 2015]. By coupling to musculoskeletal modelling, realistic loading conditions can be implemented in FE analysis. However, it is unknown whether such analyses require complex elastic-plastic material models, or whether a linear elastic calculation already provides a reasonable prediction of fracture. Moreover, plastic deformation may accumulate over time, which is ignored by linear elastic calculations. In this study we compared linear and non-linear fracture predictions under realistic loading conditions in two patients with metastatic bone disease. Methods Two patients (P1, P2) with lytic lesions were included. Patient-specific femoral geometry and bone density were retrieved from quantitative CT-scans; the latter was used for implementing element-specific material behaviour [Keyak, 2005]. Muscle forces and hip contact forces acting on the femur during walking were calculated using musculoskeletal modelling (one typical case, adapted from [Wesseling, 2014]), and subsequently normalized to the patient’s body weight. Muscle forces were applied to attachment points that were morphed onto the patient femurs. Hip contact forces were applied to a cup mimicking the acetabulum, via a control node in the hip joint centre. Two simulations were run for each patient: a linear elastic analysis simulating a single walk cycle and a non-linear elastic-plastic analysis simulating 10 subsequent walk cycles. The safety factor (SF; yield stress/Von Mises stress) and plasticity were studied as measures of femoral failure in the linear and non-linear simulations, respectively, and compared between patients. Results The volume of elements with SF<1 (Figure 1A) as well as the volume of elements that underwent plastic deformation (Figure 1B) was highest in the femur of P1. In P1 the volume of plastic deformation increased over the loading cycles and eventually exceeded the peak volume of elements with SF<1 in the linear analysis. In P2, the volume of plasticity more or less stabilized after two loading cycles, and eventually resembled the volume of elements with SF<1 in the linear analysis. Discussion These preliminary results suggest that accumulation of plasticity under cyclic loading is femur-specific. Due to the variable and local weakening of the bone strength by metastatic lesions, relatively small changes in magnitude or direction of loading may initiate local failure and catalyze progressive failure in subsequent loading cycles. Hence, in some cases a linear analysis is sufficient, while in others it is not. Non-linear material behaviour and cyclic loading conditions are therefore required to capture these phenomena

Изотопный состав подземных вод водосборного бассейна озера Поянху (Китай)

В статье приведены данные об изотопном составе ([delta]D, [delta]18O) подземных вод водосборного бассейна оз. Поянху. По соотношению изотопов [delta]D и [delta]18O определен генезис исследуемых вод, а также проанализировано возможное влияние испарительного концентрирования на формирование их состава. In the article data about isotopic composition ([delta]D, [delta]18O) of the Poyang Lake catchment groundwater is presented. Based on [delta]D and [delta]18O isotopes correlation genesis of the investigated groundwater and influence of evaporation to the groundwater composition are identified

Lunar periodicity in the shell flux of some planktonic foraminifera in the Gulf of Mexico

Synchronised reproduction offers clear benefits to planktonic foraminifera – an important group of marine calcifiers – as it increases the chances of successful gamete fusion. Such synchrony requires tuning to an internal or external clock. Evidence exists for lunar reproductive cycles in some species, but its recognition in shell flux time series has proven difficult, raising questions about reproductive strategies. Using spectral analysis of a 6 year time series (mostly at weekly resolution) from the northern Gulf of Mexico we show that the shell flux of Globorotalia menardii, Globigerinella siphonifera, Orbulina universa, Globigerinoides sacculifer and in Globigerinoides ruber (both pink and white varieties) is characterised by lunar periodicity. The fluxes of Pulleniatina obliquiloculata, Neogloboquadrina dutertrei, Globigerinella calida, Globorotalia crassaformis and Globigerinita glutinata do not show significant spectral power at the lunar frequency. If present, lunar periodicity is superimposed on longer term/seasonal changes in the shell fluxes, but accounts for a significant part of the variance in the fluxes. The amplitude of the lunar cycle increases roughly proportional with the magnitude of the flux, demonstrating that most of the population is indeed affected by lunar-phased synchronisation. Phasing of peak fluxes appears species-specific, with G. menardii, O. universa and G. sacculifer showing most peaks around the full moon and G. ruber one week later. Contrastingly, peaks G. siphonifera occur dominantly around new moon. Very limited literature exists on lunar phasing of foraminiferal export fluxes, but spatial differences in its presence may exist, corroborating the exogenous nature of lunar synchrony in planktonic foraminifera

The probability to initiate X chromosome inactivation is determined by the X to autosomal ratio and x chromosome specific allelic properties.

Background: In female mammalian cells, random X chromosome inactivation (XCI) equalizes the dosage of X-encoded gene products to that in male cells. XCI is a stochastic process, in which each X chromosome has a probability to be inactivated. To obtain more insight in the factors setting up this probability, we studied the role of the X to autosome (X:A) ratio in initiation of XCI, and have used the experimental data in a computer simulation model to study the cellular population dynamics of XCI. Methodology/Principal Findings: To obtain more insight in the role of the X:A ratio in initiation of XCI, we generated triploid mouse ES cells by fusion of haploid round spermatids with diploid female and male ES cells. These fusion experiments resulted in only XXY triploid ES cells. XYY and XXX ES lines were absent, suggesting cell death related either to insufficient X-chromosomal gene dosage (XYY) or to inheritance of an epigenetically modified X chromosome (XXX). Analysis of active (Xa) and inactive (Xi) X chromosomes in the obtained triploid XXY lines indicated that the initiation frequency of XCI is low, resulting in a mixed population of XaXiY and XaXaY cells, in which the XaXiY cells have a small proliferative advantage. This result, and findings on XCI in diploid and tetraploid ES cell lines with different X:A ratios, provides evidence that the X:A ratio determines the probability for a given X chromosome to be inactivated. Furthermore, we found that the kinetics of the XCI process can be simulated using a probability for an X chromosome to be inactivated that is proportional to the X:A ratio. These simulation studies re-emphasize our hypothesis that the probability is a function of the concentration of an X-encoded activator of XCI, and of X chromosome specific allelic properties determining the threshold for this activator. Conclusions: The present findings reveal that the probability for an X chromosome to be inactivated is proportional to the X:A ratio. This finding supports the presence of an X-encoded activator of the XCI process. © 2009 Monkhorst et al

Selective accumulation of differentiated CD8+ T cells specific for respiratory viruses in the human lung

The lungs are frequently challenged by viruses, and resident CD8+ T cells likely contribute to the surveillance of these pathogens. To obtain insight into local T cell immunity to respiratory viruses in humans, we determined the specificity, phenotype, and function of lung-residing CD8+ T cells and peripheral blood CD8+ T cells in a paired analysis. The lung contained markedly higher frequencies of influenza (FLU)-specific and respiratory syncytial virus (RSV)-specific CD8+ T cells when compared with the circulation. This contrasted with an equal distribution of cytomegalovirus- and Epstein-Bar virus–specific CD8+ T cells. Noticeably, a substantial fraction of the lung-residing FLU- and RSV-specific CD8+ T cells had progressed to a relatively late differentiation phenotype, reflected by low expression of CD28 and CD27. Lung-derived FLU-specific CD8+ T cells had low activation requirements, as expansion of these cells could be initiated by cognate peptide in the absence of helper cell–derived signals. Thus, the human lung contains high numbers of differentiated FLU- and RSV-specific memory CD8+ T cells that can readily expand upon reexposure to virus. Resident lung T cells may provide immediate immunological protection against pulmonary virus infections

The Role of a Nutrition Support Team in the Management of Intestinal Failure Patients

Parenteral nutrition (PN) is a complex and specialized form of nutrition support that has revolutionized the care for both pediatric and adult patients with acute and chronic intestinal failure (IF). This has led to the development of multidisciplinary teams focused on th

Electrons in a ferromagnetic metal with a domain wall

We present theoretical description of conduction electrons interacting with a domain wall in ferromagnetic metals. The description takes into account interaction between electrons. Within the semiclassical approximation we calculate the spin and charge distributions, particularly their modification by the domain wall. In the same approximation we calculate local transport characteristics, including relaxation times and charge and spin conductivities. It is shown that these parameters are significantly modified near the wall and this modification depends on electron-electron interaction.Comment: 10 pages with 4 figure