63 research outputs found

    Constitutive equations and wave propagation in Green\u2013Naghdi type II and III thermoelectroelasticity

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    In this article we extend the theory of thermoelasticity devised by Green and Naghdi to the framework of finite thermoelectroelasticity. Both isotropic and transversely isotropic bodies are considered and thermodynamic restrictions on their constitutive relations are obtained by virtue of the reduced energy equality. In the second part, a linearized theory for transversely isotropic ther- mopiezoelectricity is derived from thermodynamic restrictions by construct- ing the free energy as a quadratic function of the 11 second-order invariants of the basic melds. The resulting theory provides a natural extension of the (linear) Green and Naghdi theory for types II and III rigid heat conductors. As a particular case, we derive the linear system which rules the processes depending on the symmetry axis coordinate only

    Exportações brasileiras de máquinas e equipamentos agrícolas para a África: análise da situação atual e do ambiente de negócios

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    Bibliografia: p. 41-42O presente artigo tem como objetivo identificar o status atual das exportações brasileiras de máquinas e implementos agrícolas para a África, assim como seus canais de venda e distribuição. Visa ainda refletir acerca das oportunidades de ampliar a penetração desses produtos no continente. Para tanto, além da consulta às tradicionais bases de dados sobre comércio exterior, a pesquisa contou com coleta de dados primários. Foram enviados questionários a um grande número de empresas, contendo questões que versaram sobre dificuldades de exportação para a África, canais de distribuição dos bens exportados, obtenção de financiamento e concorrência. A partir da análise das informações levantadas, tornou-se possível concluir que o preço é o fator preponderante para a perda de negócios das empresas brasileiras no continente e que o financiamento tem o potencial de impulsionar a concretização de novos negócios

    Influência do entorno de uma unidade de conservação sobre a pressão de caça: RPPN Estação Veracel como estudo de caso

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    A caça de animais silvestres é uma das atividades humanas mais antigas e, associada a aplicação de técnicas de caça modernas, pode levar rapidamente a uma superexploração e até a extinção de espécies. A caça no Brasil é ilegal na maior parte dos casos, mas ainda é uma atividade comum. Por ser uma atividade ilegal, coletar e quantificar tais informação é um desafio. O presente estudo apresenta uma oportunidade rara para isso, contando com 1274 indícios de caçadores e 984 vestígios de caça coletados na Reserva Particular do Patrimônio Natural Estação Veracel (RPPN Veracel). Nesse contexto, o objetivo principal desse estudo foi avaliar se a pressão de caça na RPPN pode ser influenciada pela paisagem no entorno (i.e., presença de assentamentos rurais, áreas urbanas, estradas e proporção de matriz). Além disso, foram descritas as variações temporais nas atividades de caça na RPPN, bem como a influência de operações de fiscalização conjuntas com forças policiais nessas atividades. Foi notado que a proporção de matriz e a distância aos assentamentos de reforma agrária foram os principais vetores de pressão de caça na unidade de conservação. A detenção de caçadores pela polícia parece ter sido a principal responsável pela redução entre anos nas atividades de caça na RPPN. Diante dos resultados apresentados nesse estudo nota-se a necessidade (i) do estabelecimento de parcerias com as instituições de fiscalização e inteligência para controle da ação dos caçadores; (ii) da realização de um trabalho educativo sobre a importância da fauna silvestre junto às comunidades do entorno da RPPN e (iii) do desenvolvimento de atividades profissionalizantes que permitam a geração e o incremento de renda para essas comunidades

    Scientists warning on the ecological effects of radioactive leaks on ecosystems

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    A nuclear leakage or tactical nuclear weapon use in a limited war could cause immense and long-lasting ecological consequences beyond the direct site of exposure. We call upon all scientists to communicate the importance of the environmental impacts of such an event to all life forms on Earth, including humankind. Changes to ecosystem structure and functioning and species extinctions would alter the biosphere for an unknown time frame. Radiation could trigger cascade effects in marine, atmospheric and terrestrial ecosystems of a magnitude far beyond human capabilities for mitigation or adaptation. Even a “tactical nuclear war” could alter planet Earth’s living boundaries, ending the current Anthropocene era

    Reliability of forced internal rotation and active internal rotation to assess lateral instability of the biceps pulley

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    Purpose: the aim of this study was to investigate the relationship between positive painful forced internal rotation (FIR) and lateral pulley instability in the presence of a pre-diagnosed posterosuperior cuff tear. The same investigation was conducted for painful active internal rotation (AIR). Methods: a multicenter prospective study was conducted in a series of patients scheduled to undergo arthroscopic posterosuperior cuff repair. Pain was assessed using a visual analog scale (VAS) and the Disabilities of the Arm, Shoulder and Hand questionnaire (DASH) was administered. The VAS score at rest, DASH score, and presence/absence of pain on FIR and AIR were recorded and their relationships with lesions of the lateral pulley, cuff tear patterns and shape of lesions were analyzed. Results: the study population consisted of 115 patients (mean age: 55.1 years) recruited from 12 centers. The dominant arm was affected in 72 cases (62.6%). The average anteroposterior extension of the lesion was 1.61 cm. The mean preoperative VAS and DASH scores were 6.1 and 41.8, respectively. FIR and AIR were positive in 94 (81.7%) and 85 (73.9%) cases, respectively. The lateral pulley was compromised in 50 cases (43.4%). Cuff tears were partial articular in 35 patients (30.4%), complete in 61 (53%), and partial bursal in 19 (16.5%). No statistical correlation between positive FIR or AIR and lateral pulley lesions was detected. Positive FIR and AIR were statistically associated with complete lesions. Negative FIR was associated with the presence of partial articular tears. Conclusions: painful FIR in the presence of a postero-superior cuff tear does not indicate lateral pulley instability. When a cuff tear is suspected, positive FIR and AIR are suggestive of full-thickness tear patterns while a negative FIR suggests a partial articular lesion. Level of evidence: level I, validating cohort study with good reference standards

    Psychological treatments and psychotherapies in the neurorehabilitation of pain. Evidences and recommendations from the italian consensus conference on pain in neurorehabilitation

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    BACKGROUND: It is increasingly recognized that treating pain is crucial for effective care within neurological rehabilitation in the setting of the neurological rehabilitation. The Italian Consensus Conference on Pain in Neurorehabilitation was constituted with the purpose identifying best practices for us in this context. Along with drug therapies and physical interventions, psychological treatments have been proven to be some of the most valuable tools that can be used within a multidisciplinary approach for fostering a reduction in pain intensity. However, there is a need to elucidate what forms of psychotherapy could be effectively matched with the specific pathologies that are typically addressed by neurorehabilitation teams. OBJECTIVES: To extensively assess the available evidence which supports the use of psychological therapies for pain reduction in neurological diseases. METHODS: A systematic review of the studies evaluating the effect of psychotherapies on pain intensity in neurological disorders was performed through an electronic search using PUBMED, EMBASE, and the Cochrane Database of Systematic Reviews. Based on the level of evidence of the included studies, recommendations were outlined separately for the different conditions. RESULTS: The literature search yielded 2352 results and the final database included 400 articles. The overall strength of the recommendations was medium/low. The different forms of psychological interventions, including Cognitive-Behavioral Therapy, cognitive or behavioral techniques, Mindfulness, hypnosis, Acceptance and Commitment Therapy (ACT), Brief Interpersonal Therapy, virtual reality interventions, various forms of biofeedback and mirror therapy were found to be effective for pain reduction in pathologies such as musculoskeletal pain, fibromyalgia, Complex Regional Pain Syndrome, Central Post-Stroke pain, Phantom Limb Pain, pain secondary to Spinal Cord Injury, multiple sclerosis and other debilitating syndromes, diabetic neuropathy, Medically Unexplained Symptoms, migraine and headache. CONCLUSIONS: Psychological interventions and psychotherapies are safe and effective treatments that can be used within an integrated approach for patients undergoing neurological rehabilitation for pain. The different interventions can be specifically selected depending on the disease being treated. A table of evidence and recommendations from the Italian Consensus Conference on Pain in Neurorehabilitation is also provided in the final part of the pape

    Evaluating the impact of modeling the family effect for clonal selection in potato-breeding programs

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    Because of its wide distribution, high yield potential, and short cycle, the potato has become essential for global food security. However, the complexity of tetrasomic inheritance, the high level of heterozygosity of the parents, the low multiplication rate of tubers, and the genotype-by-environment interactions impose severe challenges on tetraploid potato–breeding programs. The initial stages of selection take place in experiments with low selection accuracy for many of the quantitative traits of interest, for example, tuber yield. The goal of this study was to investigate the contribution of incorporating a family effect in the estimation of the total genotypic effect and selection of clones in the initial stage of a potato-breeding program. The evaluation included single trials (STs) and multi-environment trials (METs). A total of 1,280 clones from 67 full-sib families from the potato-breeding program at Universidade Federal de Lavras were evaluated for the traits total tuber yield and specific gravity. These clones were distributed in six evaluated trials that varied according to the heat stress level: without heat stress, moderate heat stress, and high heat stress. To verify the importance of the family effect, models with and without the family effect were compared for the analysis of ST and MET data for both traits. The models that included the family effect were better adjusted in the ST and MET data analyses for both traits, except when the family effect was not significant. Furthermore, the inclusion of the family effect increased the selective efficiency of clones in both ST and MET analyses via an increase in the accuracy of the total genotypic value. These same models also allowed the prediction of clone effects more realistically, as the variance components associated with family and clone effects within a family were not confounded. Thus, clonal selection based on the total genotypic value, combining the effects of family and clones within a family, proved to be a good alternative for potato-breeding programs that can accommodate the logistic and data tracking required in the breeding program

    What is the role of the placebo effect for pain relief in neurorehabilitation? Clinical implications from the Italian consensus conference on pain in neurorehabilitation

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    Background: It is increasingly acknowledged that the outcomes of medical treatments are influenced by the context of the clinical encounter through the mechanisms of the placebo effect. The phenomenon of placebo analgesia might be exploited to maximize the efficacy of neurorehabilitation treatments. Since its intensity varies across neurological disorders, the Italian Consensus Conference on Pain in Neurorehabilitation (ICCP) summarized the studies on this field to provide guidance on its use. Methods: A review of the existing reviews and meta-analyses was performed to assess the magnitude of the placebo effect in disorders that may undergo neurorehabilitation treatment. The search was performed on Pubmed using placebo, pain, and the names of neurological disorders as keywords. Methodological quality was assessed using a pre-existing checklist. Data about the magnitude of the placebo effect were extracted from the included reviews and were commented in a narrative form. Results: 11 articles were included in this review. Placebo treatments showed weak effects in central neuropathic pain (pain reduction from 0.44 to 0.66 on a 0-10 scale) and moderate effects in postherpetic neuralgia (1.16), in diabetic peripheral neuropathy (1.45), and in pain associated to HIV (1.82). Moderate effects were also found on pain due to fibromyalgia and migraine; only weak short-term effects were found in complex regional pain syndrome. Confounding variables might have influenced these results. Clinical implications: These estimates should be interpreted with caution, but underscore that the placebo effect can be exploited in neurorehabilitation programs. It is not necessary to conceal its use from the patient. Knowledge of placebo mechanisms can be used to shape the doctor-patient relationship, to reduce the use of analgesic drugs and to train the patient to become an active agent of the therapy
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