One-dimensional Gapless Magnons In A Single Anisotropic Ferromagnetic Nanolayer.

Gapless magnons in a plane ferromagnet with normal axis anisotropy are shown to exist besides the usual gapped modes that affect spin dependent transport properties only above a finite temperature. These magnons are one-dimensional objects, in the sense that they are localized inside the domain walls that form in the film. They may play an essential role in the spin dependent scattering processes even down to very low temperatures.9122680

NMR linewidth and Skyrmion localization in quantum Hall ferromagnets

The non-monotonic behavior of the NMR signal linewidth in the 2D quantum Hall system is explained in terms of the interplay between skyrmions localization, due to the influence of disorder, and the non-trivial temperature dependent skyrmion dynamics.Comment: 5 pages, 2 figure

Perturbações alimentares em portugal: padrões de utilização dos serviços

As perturbações alimentares (anorexia nervosa e bulimia nervosa) são problemas psicopatológicos sérios que afectam principalmente as mulheres jovens. Neste âmbito, Portugal participou num projecto de investigação de europeu, enquadrado nas acções do COST — Cooperation on Science and Technology, sobre a eficácia da psicoterapia das perturbações alimentares, a Acção COST-B6. O presente artigo apresenta uma caracterização dos utentes que recorreram a um destes centros de tratamento especializado no Norte, Centro ou Sul do país, durante o período do estudo. Durante o estudo 170 pacientes do sexo feminino, diagnosticados com uma Anorexia Nervosa ou Bulimia Nervosa de acordo com os critérios de diagnóstico do DSM-IV, iniciaram o tratamento neste período. Os pacientes responderam a vários instrumentos de avaliação clínica antes do início do tratamento. Os resultados mostraram que uma proporção considerável dos utentes é jovem e que os índices de gravidade dos sintomas demonstram um considerável comprometimento do nível de funcionamento esperado. Tal como esperado os pacientes com perturbação do comportamento alimentar apresentam resultados, nas escalas de avaliação das perturbações alimentares, superiores aos da população normal, confirmando a gravidade dos sintomas no momento da amissão ao tratamento. Curiosamente, os pacientes bulímicos tendem a apresentar resultados mais elevados nestas escalas clínicas, sugerindo um nível mais elevado nível de sofrimento subjectivo. Por último, a proporção dos pacientes com bulimia nervosa e anorexia nervosa que se apresentaram ao tratamento são semelhantes, o que poderá sugerir que um número significativo de pacientes bulímicos não recebe tratamento especializado.Fundação para a Ciência e a Tecnologia (FCT) - PRAXIS/PCSH/P/PSI/85/9

Detection of drug-drug interactions by modeling interaction profile fingerprints

Drug-drug interactions (DDIs) constitute an important problem in postmarketing pharmacovigilance and in the development of new drugs. The effectiveness or toxicity of a medication could be affected by the co-administration of other drugs that share pharmacokinetic or pharmacodynamic pathways. For this reason, a great effort is being made to develop new methodologies to detect and assess DDIs. In this article, we present a novel method based on drug interaction profile fingerprints (IPFs) with successful application to DDI detection. IPFs were generated based on the DrugBank database, which provided 9,454 well-established DDIs as a primary source of interaction data. The model uses IPFs to measure the similarity of pairs of drugs and generates new putative DDIs from the non-intersecting interactions of a pair. We described as part of our analysis the pharmacological and biological effects associated with the putative interactions; for example, the interaction between haloperidol and dicyclomine can cause increased risk of psychosis and tardive dyskinesia. First, we evaluated the method through hold-out validation and then by using four independent test sets that did not overlap with DrugBank. Precision for the test sets ranged from 0.4–0.5 with more than two fold enrichment factor enhancement. In conclusion, we demonstrated the usefulness of the method in pharmacovigilance as a DDI predictor, and created a dataset of potential DDIs, highlighting the etiology or pharmacological effect of the DDI, and providing an exploratory tool to facilitate decision support in DDI detection and patient safety.This work was supported by grants R01 LM010016 (CF), R01 LM010016-0S1 (CF), R01 LM010016-0S2 (CF), R01 LM008635 (CF), “Plan Galego de Investigación, Innovación e Crece-mento 2011–2015 (I2C)”, European Social Fund (ESF) and Angeles Alvariño program from Xunta de Galicia (Spain)S

Domain-wall profile in the presence of anisotropic exchange interactions: Effective on-site anisotropy

Starting from a D-dimensional XXZ ferromagnetic Heisenberg model in an hypercubic lattice, it is demonstrated that the anisotropy in the exchange coupling constant leads to a D-dependent effective on-site anisotropy interaction often ignored for D>1. As a result the effective width of the wall depends on the dimensionality of the system. It is shown that the effective one-dimensional Hamiltonian is not the one-dimensional XXZ version as assumed in previous theoretical work. We derive a new expression for the wall profile that generalizes the standard Landau-Lifshitz form. Our results are found to be in very good agreement with earlier numerical work using the Monte Carlo method. Preceding theories concerning the domain wall contribution to magnetoresistance have considered the role of D only through the modification of the density of states in the electronic band structure. This Brief Report reveals that the wall profile itself contains an additional D dependence for the case of anisotropic exchange interactions.Comment: 4 pages; new title and abstract; 1 figure comparing our results with earlier numerical work; a more general model containing the usual on-site anisotropy; new remarks and references on the following two topics: (a) experimental evidence for the existence of spin exchange anisotropy, and (b) preceding theories concerning the domain wall contribution to magnetoresistance; to appear in Phys. Rev.

Bricolage as Survival, Growth and Transformation:the Role of Patchworking in the Social Agency of Migrant Entrepreneurs

This article examines the patch-working strategies of migrant entrepreneurs as a form of social agency. ‘Patch-working’ – the reliance on supplementary forms of income to support business activity – is often seen as a means of cushioning the financial vulnerability of small firms. However, the mechanisms and forms that patch-working takes tend to be overlooked. Evidence from 42 West Midlands’ firms shows that, despite the highly constrained operating environment, the exercise of social agency can help to cushion against disadvantage and to rework their current conditions through patch-working. This allows for business growth, and even transformational growth in some cases, rather than sheer survival. Even so, our findings show that the agency of migrant entrepreneurs brings about only minor improvements in revenue and is certainly not capable of fundamentally changing either the nature of the sector or the structure of the labour market in which they are embedded

Identification of a Human SOCS1 Polymorphism That Predicts Rheumatoid Arthritis Severity

Rheumatoid arthritis (RA) is a chronic inflammatory disease characterized by an autoimmune response in the joints and an exacerbation of cytokine responses. A minority of patients with RA experience spontaneous remission, but most will show moderate/high disease activity, with aggressive joint damage and multiple systemic manifestations. There is thus is a great need to identify prognostic biomarkers for disease risk to improve diagnosis and prognosis, and to inform on the most appropriate therapy. Here we focused on suppressor of cytokine signaling 1 (SOCS1), a physiological negative regulator of cytokines that modulates cell activation. Using four independent cohorts of patients with arthritis, we characterized the correlation between SOCS1 mRNA levels and clinical outcome. We found a significant inverse correlation between SOCS1 mRNA expression and disease activity throughout the follow-up of patients with RA. Lower baseline SOCS1 levels were associated with poorer disease control in response to methotrexate and other conventional synthetic disease-modifying anti-rheumatic drugs in early arthritis, and to rituximab in established (active) RA. Moreover, we identified several single nucleotide polymorphisms in the SOCS1 gene that correlated with SOCS1 mRNA expression, and that might identify those patients with early arthritis that fulfill RA classification criteria. One of them, rs4780355, is in linkage disequilibrium with a microsatellite (TTTTC)3−5, mapped 0.9 kb downstream of the SNP, and correlated with reduced SOCS1 expression in vitro. Overall, our data support the association between SOCS1 expression and disease progression, disease severity and response to treatment in RA. These observations underlie the relevance of SOCS1 mRNA levels for stratifying patients prognostically and guiding therapeutic decisions