1,896 research outputs found

    Tailoring Three-Point Functions and Integrability III. Classical Tunneling

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    We compute three-point functions between one large classical operator and two large BPS operators at weak coupling. We consider operators made out of the scalars of N=4 SYM, dual to strings moving in the sphere. The three-point function exponentiates and can be thought of as a classical tunneling process in which the classical string-like operator decays into two classical BPS states. From an Integrability/Condensed Matter point of view, we simplified inner products of spin chain Bethe states in a classical limit corresponding to long wavelength excitations above the ferromagnetic vacuum. As a by-product we solved a new long-range Ising model in the thermodynamic limit.Comment: 37 pages, 10 figure

    Persistence of magnetic field driven by relativistic electrons in a plasma

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    The onset and evolution of magnetic fields in laboratory and astrophysical plasmas is determined by several mechanisms, including instabilities, dynamo effects and ultra-high energy particle flows through gas, plasma and interstellar-media. These processes are relevant over a wide range of conditions, from cosmic ray acceleration and gamma ray bursts to nuclear fusion in stars. The disparate temporal and spatial scales where each operates can be reconciled by scaling parameters that enable to recreate astrophysical conditions in the laboratory. Here we unveil a new mechanism by which the flow of ultra-energetic particles can strongly magnetize the boundary between the plasma and the non-ionized gas to magnetic fields up to 10-100 Tesla (micro Tesla in astrophysical conditions). The physics is observed from the first time-resolved large scale magnetic field measurements obtained in a laser wakefield accelerator. Particle-in-cell simulations capturing the global plasma and field dynamics over the full plasma length confirm the experimental measurements. These results open new paths for the exploration and modelling of ultra high energy particle driven magnetic field generation in the laboratory

    Influence of dietary n-6 and n-3 lipids upon the development of pulmonary granulomas induced by Schistosoma mansoni eggs

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    Pulmonary granuloma development was studied in mice injected with 2x103 Schistosoma mansoni eggs through the main tail vein. Mice were divided into three groups and fed with a laboratory manipulated diet differing among them only in the source of fatty acids. Control group (CT) was fed with a soya oil diet; n-6 deficient animals (low n-6 group) received a supplemented coconut fat diet; and the third group, high n-3, was fed with a cod liver oil diet. The expected anti-inflammatory actions associated with essential fatty acids deficiency was noticed in our system. When compared with CT, animals fed with the n-6 deficient diet presented significantly reduced pulmonary granulomas 32 days after egg injection. Mice fed with high n-3 diet had pulmonary granulomas reduced as soon as 16 days post egg injection. Mean granuloma measurements for CT at days 8, 16 and 32 were, in 103μ2, respectively 7.52 5.92, 32.70 18.09, 32.22 19.87; for n-6 deficient animals 17.65 18.85, 36.14 29.14, 24.45 14.06; and for high n-3 group were 11.60 12.67, 9.97 12.34, 25.54 16.66

    Three-Dimensional kinetic adaptations of gait throughout pregnancy and postpartum

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    The present publication was supported by the following projects: (1) funder, Fundação para a Ciência e Tecnologia (FCT)/Portuguese Foundation for Science and Technology, project title: Effect of Biomechanical Loading on the Musculoskeletal System in Women during Pregnancy and the Postpartum Period; promoter, CIPER/FMH-UL/ESDRM-IPS; Principal Researcher, Rita Santos-Rocha; and project reference, PTDC/DES/102058/2008; (2) funder, European Union: QREN-InAlentejo-Programa Operacional do Alentejo-2007–2013/National Strategic Reference Framework, project title: Alentejo’s Science and Technology Park, Sport and Health Research Center; promoter: Polytechnic Institute of Santarém, Sport Sciences School of Rio Maior/Health School of Santarém; Project Coordinator, Rita Santos-Rocha; and project reference, ALENT-07-0262-FEDER-001883.Biomechanical adaptations that occur during pregnancy can lead to changes on gait pattern. Nevertheless, these adaptations of gait are still not fully understood. The purpose was to determine the effect of pregnancy on the biomechanical pattern of walking, regarding the kinetic parameters. A three-dimensional analysis was performed in eleven participants. The kinetic parameters in the joints of the lower limb during gait were compared at the end of the first, second, and third trimesters of pregnancy and in the postpartum period, in healthy pregnant women. The main results showed a reduction in the normalized vertical reaction forces, throughout pregnancy, particularly the third peak. Pregnant women showed, during most of the stance phase, medial reaction forces as a motor response to promote the body stability. Bilateral changes were observed in hip joint, with a decrease in the participation of the hip extensors and in the eccentric contraction of hip flexors. In ankle joint a decrease in the participation of ankle plantar flexors was found. In conclusion, the overall results point to biomechanical adjustments that showed a decrease of the mechanical load of women throughout pregnancy, with exception for few unilateral changes of hip joint moments

    Lactate signalling regulates fungal β-glucan masking and immune evasion

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    AJPB: This work was supported by the European Research Council (STRIFE, ERC- 2009-AdG-249793), The UK Medical Research Council (MR/M026663/1), the UK Biotechnology and Biological Research Council (BB/K017365/1), the Wellcome Trust (080088; 097377). ERB: This work was supported by the UK Biotechnology and Biological Research Council (BB/M014525/1). GMA: Supported by the CNPq-Brazil (Science without Borders fellowship 202976/2014-9). GDB: Wellcome Trust (102705). CAM: This work was supported by the UK Medical Research Council (G0400284). DMM: This work was supported by UK National Centre for the Replacement, Refinement and Reduction of Animals in Research (NC/K000306/1). NARG/JW: Wellcome Trust (086827, 075470,101873) and Wellcome Trust Strategic Award in Medical Mycology and Fungal Immunology (097377). ALL: This work was supported by the MRC Centre for Medical Mycology and the University of Aberdeen (MR/N006364/1).Peer reviewedPostprin

    Finite-gap equations for strings on AdS_3 x S^3 x T^4 with mixed 3-form flux

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    We study superstrings on AdS_3 x S^3 x T^4 supported by a combination of Ramond-Ramond and Neveu-Schwarz-Neveu-Schwarz three form fluxes, and construct a set of finite-gap equations that describe the classical string spectrum. Using the recently proposed all-loop S-matrix we write down the all-loop Bethe ansatz equations for the massive sector. In the thermodynamic limit the Bethe ansatz reproduces the finite-gap equations. As part of this derivation we propose expressions for the leading order dressing phases. These phases differ from the well-known Arutyunov-Frolov-Staudacher phase that appears in the pure Ramond-Ramond case. We also consider the one-loop quantization of the algebraic curve and determine the one-loop corrections to the dressing phases. Finally we consider some classical string solutions including finite size giant magnons and circular strings.Comment: 44 pages, 3 figures. v2: references and a discussion about perturbative results adde

    Spectrum of ankylosing spondylitis in Portugal. Development of BASDAI, BASFI, BASMI and mSASSS reference centile charts

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    The availability of population-specific normative data regarding disease severity measures is essential for patient assessment. The goals of the current study were to characterize the pattern of ankylosing spondylitis (AS) in Portuguese patients and to develop reference centile charts for BASDAI, BASFI, BASMI and mSASSS, the most widely used assessment tools in AS. AS cases were recruited from hospital outpatient clinics, with AS defined according to the modified New York criteria. Demographic and clinical data were recorded. All radiographs were evaluated by two independent experienced readers. Centile charts for BASDAI, BASFI, BASMI and mSASSS were constructed for both genders, using generalized linear models and regression models with duration of disease as independent variable. A total of 369 patients (62.3% male, mean ± (SD) age 45.4 ± 13.2 years, mean ± (SD) disease duration 11.4 ± 10.5 years, 70.7% B27-positive) were included. Family history of AS in a first-degree relative was reported in 17.6% of the cases. Regarding clinical disease pattern, at the time of assessment 42.3% had axial disease, 2.4% peripheral disease, 40.9% mixed disease and 7.1% isolated enthesopatic disease. Anterior uveitis (33.6%) was the most common extra-articular manifestation. The centile charts suggest that females reported greater disease activity and more functional impairment than males but had lower BASMI and mSASSS scores. Data collected through this study provided a demographic and clinical profile of patients with AS in Portugal. The development of centile charts constitutes a useful tool to assess the change of disease pattern over time and in response to therapeutic interventions

    Identification of a cytokine network sustaining neutrophil and Th17 activation in untreated early rheumatoid arthritis

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    © 2010 Cascão et al.; licensee BioMed Central Ltd. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Introduction: Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease characterized by sustained synovitis. Recently, several studies have proposed neutrophils and Th17 cells as key players in the onset and perpetuation of this disease. The main goal of this work was to determine whether cytokines driving neutrophil and Th17 activation are dysregulated in very early rheumatoid arthritis patients with less than 6 weeks of disease duration and before treatment (VERA). Methods: Cytokines related to neutrophil and Th17 activation were quantified in the serum of VERA and established RA patients and compared with other very early arthritis (VEA) and healthy controls. Synovial fluid (SF) from RA and osteoarthritis (OA) patients was also analyzed. Results: VERA patients had increased serum levels of cytokines promoting Th17 polarization (IL-1b and IL-6), as well as IL-8 and Th17-derived cytokines (IL-17A and IL-22) known to induce neutrophil-mediated inflammation. In established RA this pattern is more evident within the SF. Early treatment with methotrexate or corticosteroids led to clinical improvement but without an impact on the cytokine pattern. Conclusions: VERA patients already display increased levels of cytokines related with Th17 polarization and neutrophil recruitment and activation, a dysregulation also found in SF of established RA. 0 Thus, our data suggest that a cytokine-milieu favoring Th17 and neutrophil activity is an early event in RA pathogenesis.This work was supported by a grant from Sociedade Portuguesa de Reumatologia/Schering-Plough 2005. RAM and RC were funded by Fundação para a Ciência e a Tecnologia (FCT) SFRH/BD/30247/2006 and SFRH/BD/40513/2007, respectively. MMS-C was funded by Marie Curie Intra-European Fellowship PERG-2008-239422 and a EULAR Young Investigator Award

    Violência autoinfligida por intoxicação exógena em um serviço de urgência e emergência

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    RESUMO Objetivo Analisar as violências autoinfligidas por intoxicação exógena notificadas em um serviço de saúde. Métodos Estudo epidemiológico, retrospectivo e analítico realizado em um serviço de urgência e emergência do município de Teresina, Piauí. Procedeu-se nos meses de janeiro e fevereiro de 2015, mediante análise de todos os casos de violência autoinfligida por intoxicação exógena notificados no Sistema de Informação de Agravos de Notificação, no período de 2009 a 2014. O teste qui-quadrado de Pearson foi utilizado na análise. Resultados Foram notificadas 277 vítimas de violência autoinfligida por intoxicação exógena, sendo que 10,5% morreram por suicídio. Houve associação entre o óbito e as variáveis idade, escolaridade, zona de ocorrência e tipo de exposição, assim como entre o tipo de exposição e a quantidade de agentes utilizados. Conclusão Os resultados fornecem subsídios para a definição de estratégias de prevenção considerando os grupos vulneráveis e a complexidade dos fatores associados à violência autoinfligida
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