113 research outputs found

    Fresh inflation: a warm inflationary model from a zero temperature initial state

    Full text link
    A two-components mixture fluid which complies with the gamma law is considered in the framework of inflation with finite temperature. The model is developed for a quartic scalar potential without symmetry breaking. The radiation energy density is assumed to be zero when inflation starts and remains below the GUT temperature during the inflationary stage. Furthermore, provides the necessary number of e-folds and sufficient radiation energy density to GUT baryogenesis can take place near the minimum energetic configuration.Comment: 11 pages, no figures, to be published in Phys. Rev.

    Conservation Laws in Higher-Order Nonlinear Optical Effects

    Full text link
    Conservation laws of the nonlinear Schr\"{o}dinger equation are studied in the presence of higher-order nonlinear optical effects including the third-order dispersion and the self-steepening. In a context of group theory, we derive a general expression for infinitely many conserved currents and charges of the coupled higher-order nonlinear Schr\"{o}dinger equation. The first few currents and charges are also presented explicitly. Due to the higher-order effects, conservation laws of the nonlinear Schr\"{o}dinger equation are violated in general. The differences between the types of the conserved currents for the Hirota and the Sasa-Satsuma equations imply that the higher-order terms determine the inherent types of conserved quantities for each integrable cases of the higher-order nonlinear Schr\"{o}dinger equation

    Avaliação da casca de mamona na alimentação de ovinos.

    Get PDF
    Resumo: Objetivou-se com este trabalho, avaliar a casca de mamona na alimentação de ovinos. Foram utilizadas quatro fêmeas ovinas jovens, sem raça definida, com peso vivo médio de 30 kg e idade média de sete meses. Os animais foram mantidos em gaiolas de metabolismo e distribuídos em um delineamento em quadrado latino 4 x 4 para avaliar o efeito de quatro níveis de inclusão da casca de mamona em substituição ao milho em dietas isoprotéicas e isoenergéticas. Como alimento volumoso foi utilizado o feno de capim-Tifton, mantendo uma relação volumoso:concentrado de 60:40. Cada período experimental teve duração de 21 dias, sendo 14 dias de adaptação e sete dias de coleta de dados. Foram mensuradas as seguintes variáveis: a composição bromatológica e o valor de energia da casca de mamona, o consumo voluntário, a digestibilidade da matéria seca e de nutrientes e o balanço de nitrogênio. Houve uma redução no consumo da matéria seca e na digestibilidade da matéria orgânica com o aumento na participação da casca de mamona (P < 0,05). Com a substituição de 72,92% do milho por casca de mamona, houve também uma redução significativa da digestibilidade da fibra (P < 0,05). Não houve efeito dos tratamentos sobre o balanço de nitrogênio (P < 0,05), nem sintomas de intoxicação nos animais. A casca de mamona com 13% de sementes em sua composição, não apresentam efeitos tóxicos em níveis de até 15,25% da matéria seca da dieta, sendo um alimento com potencial de uso em dietas para pequenos ruminantes. [Castor bean hulls in the female sheep diets]. Abstract - This experiment was assigned to evaluate the castor bean hulls in the sheep feeding Four 7 month old young females, weighting 30 kg were used. They were set in metabolic cages and distributed in a 4 x 4 Latin Square design to evaluate the effect of four levels of castor bean hulls inclusion in substitution of corn grain diets. Bermudagrass hay was the forage used, maintaining a roughage:concentrate ratio 60:40. Each experimental period had duration of 21 days, being 14 days of adaptation and 7 days of data collection. The variables evaluated were: bromatologic composition and energy value of castor bean hulls, voluntary feed intake, dry matter and nutrients digestibility and nitrogen balance. There was a reduction in dry matter intake and in digestibility of organic matter with the increasing participation of castor bean hulls (P < 0.05). When the substitution from corn grain to castor bean hulls achieved 72.92%, there was also a significant reduction in fiber digestibility (P < 0.05). On the other hand, there was not effect of the treatments on nitrogen balance (P < 0.05) and did not occur intoxication symptoms in the animals. The castor bean hulls, with 13% of seed in their composition, did not present toxic effect in levels up to 15.25% of the dry matter, being a potential food source to be used in small ruminant diets

    The Ubiquitous Inflaton in String-Inspired Models

    Get PDF
    A string theory based inflationary model is developed where the inflaton interacts with a multitude of massive string level states causing dissipation of vacuum energy. Inflation terminates in a warm Universe without the need for reheating.Comment: In Press Physical Review Letters 1999, modified titl

    Cooperation, Norms, and Revolutions: A Unified Game-Theoretical Approach

    Get PDF
    Cooperation is of utmost importance to society as a whole, but is often challenged by individual self-interests. While game theory has studied this problem extensively, there is little work on interactions within and across groups with different preferences or beliefs. Yet, people from different social or cultural backgrounds often meet and interact. This can yield conflict, since behavior that is considered cooperative by one population might be perceived as non-cooperative from the viewpoint of another. To understand the dynamics and outcome of the competitive interactions within and between groups, we study game-dynamical replicator equations for multiple populations with incompatible interests and different power (be this due to different population sizes, material resources, social capital, or other factors). These equations allow us to address various important questions: For example, can cooperation in the prisoner's dilemma be promoted, when two interacting groups have different preferences? Under what conditions can costly punishment, or other mechanisms, foster the evolution of norms? When does cooperation fail, leading to antagonistic behavior, conflict, or even revolutions? And what incentives are needed to reach peaceful agreements between groups with conflicting interests? Our detailed quantitative analysis reveals a large variety of interesting results, which are relevant for society, law and economics, and have implications for the evolution of language and culture as well

    Rationales, design and recruitment for the Elfe longitudinal study

    Get PDF
    Background Many factors act simultaneously in childhood to influence health status, life chances and well being, including pre-birth influences, the environmental pollutants of early life, health status but also the social influences of family and school. A cohort study is needed to disentangle these influences and explore attribution. Methods Elfe will be a nationally representative cohort of 20 000 children followed from birth to adulthood using a multidisciplinary approach. The cohort will be based on the INSEE Permanent Demographic Panel (EDP) established using census data and civil records. The sample size has been defined in order to match the representativeness criteria and to obtain some prevalence estimation, but also to address the research area of low exposure/rare effects. The cohort will be based on repeated surveys by face to face or phone interview (at birth and each year) as well as medical interview (at 2 years) and examination (at 6 years). Furthermore, biological samples will be taken at birth to evaluate the foetal exposition to toxic substances, environmental sensors will be placed in the child's homes. Pilot studies have been initiated in 2007 (500 children) with an overall acceptance rate of 55% and are currently under progress, the 2-year survey being carried out in October this year. Discussion The longitudinal study will provide a unique source of data to analyse the development of children in their environment, to study the various factors interacting throughout the life course up to adulthood and to determine the impact of childhood experience on the individual's physical, psychological, social and professional development

    Cross-Sector Partnerships to Address Social Issues: Challenges to Theory and Practice

    Full text link

    Comparison of intra-articular injections of Hyaluronic Acid and Corticosteroid in the treatment of Osteoarthritis of the hip in comparison with intra-articular injections of Bupivacaine. Design of a prospective, randomized, controlled study with blinding of the patients and outcome assessors

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Although intra-articular hyaluronic acid is well established as a treatment for osteoarthritis of the knee, its use in hip osteoarthritis is not based on large randomized controlled trials. There is a need for more rigorously designed studies on hip osteoarthritis treatment as this subject is still very much under debate.</p> <p>Methods/Design</p> <p>Randomized, controlled trial with a three-armed, parallel-group design. Approximately 315 patients complying with the inclusion and exclusion criteria will be randomized into one of the following treatment groups: infiltration of the hip joint with hyaluronic acid, with a corticosteroid or with 0.125% bupivacaine.</p> <p>The following outcome measure instruments will be assessed at baseline, i.e. before the intra-articular injection of one of the study products, and then again at six weeks, 3 and 6 months after the initial injection: Pain (100 mm VAS), Harris Hip Score and HOOS, patient assessment of their clinical status (worse, stable or better then at the time of enrollment) and intake of pain rescue medication (number per week). In addition patients will be asked if they have complications/adverse events. The six-month follow-up period for all patients will begin on the date the first injection is administered.</p> <p>Discussion</p> <p>This randomized, controlled, three-arm study will hopefully provide robust information on two of the intra-articular treatments used in hip osteoarthritis, in comparison to bupivacaine.</p> <p>Trial registration</p> <p>NCT01079455</p

    Non-pharmacological care for patients with generalized osteoarthritis: design of a randomized clinical trial

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Non-pharmacological treatment (NPT) is a useful treatment option in the management of hip or knee osteoarthritis. To our knowledge however, no studies have investigated the effect of NPT in patients with generalized osteoarthritis (GOA). The primary aim of this study is to compare the effectiveness of two currently existing health care programs with different intensity and mode of delivery on daily functioning in patients with GOA. The secondary objective is to compare the cost-effectiveness of both interventions.</p> <p>Methods/Design</p> <p>In this randomized, single blind, clinical trial with active controls, we aim to include 170 patients with GOA. The experimental intervention consist of six self-management group sessions provided by a multi-disciplinary team (occupational therapist, physiotherapist, dietician and specialized nurse). The active control group consists of two group sessions and four sessions by telephone, provided by a specialized nurse and physiotherapist. Both therapies last six weeks. Main study outcome is daily functioning during the first year after the treatment, assessed on the Health Assessment Questionnaire. Secondary outcomes are health related quality of life, specific complaints, fatigue, and costs. Illness cognitions, global perceived effect and self-efficacy, will also be assessed for a responder analysis. Outcome assessments are performed directly after the intervention, after 26 weeks and after 52 weeks.</p> <p>Discussion</p> <p>This article describes the design of a randomized, single blind, clinical trial with a one year follow up to compare the costs and effectiveness of two non-pharmacological interventions with different modes of delivery for patients with GOA.</p> <p>Trial registration</p> <p>Dutch Trial Register NTR2137</p

    A Review on the Mechanical Modeling of Composite Manufacturing Processes

    Get PDF
    © 2016, The Author(s). The increased usage of fiber reinforced polymer composites in load bearing applications requires a detailed understanding of the process induced residual stresses and their effect on the shape distortions. This is utmost necessary in order to have more reliable composite manufacturing since the residual stresses alter the internal stress level of the composite part during the service life and the residual shape distortions may lead to not meeting the desired geometrical tolerances. The occurrence of residual stresses during the manufacturing process inherently contains diverse interactions between the involved physical phenomena mainly related to material flow, heat transfer and polymerization or crystallization. Development of numerical process models is required for virtual design and optimization of the composite manufacturing process which avoids the expensive trial-and-error based approaches. The process models as well as applications focusing on the prediction of residual stresses and shape distortions taking place in composite manufacturing are discussed in this study. The applications on both thermoset and thermoplastic based composites are reviewed in detail
    • …
    corecore