3,556 research outputs found

    Substantiation data for hypersonic cruise vehicle wing structure evaluation - Volume 1, sections 1-10

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    Trajectory, load, aerodynamic heating, materials, structural, and thermal analyses for hypersonic cruise vehicle wing

    Critical Scale-invariance in Healthy Human Heart Rate

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    We demonstrate the robust scale-invariance in the probability density function (PDF) of detrended healthy human heart rate increments, which is preserved not only in a quiescent condition, but also in a dynamic state where the mean level of heart rate is dramatically changing. This scale-independent and fractal structure is markedly different from the scale-dependent PDF evolution observed in a turbulent-like, cascade heart rate model. These results strongly support the view that healthy human heart rate is controlled to converge continually to a critical state.Comment: 9 pages, 3 figures. Phys. Rev. Lett., to appear (2004

    Replica symmetry breaking in an adiabatic spin-glass model of adaptive evolution

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    We study evolutionary canalization using a spin-glass model with replica theory, where spins and their interactions are dynamic variables whose configurations correspond to phenotypes and genotypes, respectively. The spins are updated under temperature T_S, and the genotypes evolve under temperature T_J, according to the evolutionary fitness. It is found that adaptation occurs at T_S < T_S^{RS}, and a replica symmetric phase emerges at T_S^{RSB} < T_S < T_S^{RS}. The replica symmetric phase implies canalization, and replica symmetry breaking at lower temperatures indicates loss of robustness.Comment: 5pages, 2 figure

    First quantized approaches to neutrino oscillations and second quantization

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    Neutrino oscillations are treated from the point of view of relativistic first quantized theories and compared to second quantized treatments. Within first quantized theories, general oscillation probabilities can be found for Dirac fermions and charged spin 0 bosons. A clear modification in the oscillation formulas can be obtained and its origin is elucidated and confirmed to be inevitable from completeness and causality requirements. The left-handed nature of created and detected neutrinos can also be implemented in the first quantized Dirac theory in presence of mixing; the probability loss due to the changing of initially left-handed neutrinos to the undetected right-handed neutrinos can be obtained in analytic form. Concerning second quantized approaches, it is shown in a calculation using virtual neutrino propagation that both neutrinos and antineutrinos may also contribute as intermediate particles. The sign of the contributing neutrino energy may have to be chosen explicitly without being automatic in the formalism. At last, a simple second quantized description of the flavor oscillation phenomenon is devised. In this description there is no interference terms between positive and negative components, but it still gives simple normalized oscillation probabilities. A new effect appearing in this context is an inevitable but tiny violation of the initial flavor of neutrinos. The probability loss due to the conversion of left-handed neutrinos to right-handed neutrinos is also presented.Comment: version accepted for publicatio

    Morfina como primeiro medicamento para tratamento da dor de câncer

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    BACKGROUND AND OBJECTIVES:the medications used according to the recommendation of the World Health Organization do not promote pain relief in a number of patients with cancer pain. The aim of this study was to evaluate the use of morphine as first medication for the treatment of moderate cancer pain in patients with advanced and/or metastatic disease, as an option to the recommendations of the World Health Organization analgesic ladder.METHOD:sixty patients without opioid therapy, with >18 years of age, were randomized into two groups. G1 patients received medication according to the analgesic ladder and started treatment with non-opioids in the first, weak opioids in the second, and strong opioids in the third step; G2 patients received morphine as first analgesic medication. The efficacy and tolerability of initial use of morphine were evaluated every two weeks for three months.RESULTS:the groups were similar with respect to demographic data. There was no significant difference between the groups regarding pain intensity, quality of life, physical capacity, satisfaction with treatment, need for complementation and dose of morphine. In G1 there was a higher incidence of nausea (p = 0.0088), drowsiness (p = 0.0005), constipation (p = 0.0071) and dizziness (p = 0.0376) in the second visit and drowsiness (p = 0.05) in the third.CONCLUSIONS:the use of morphine as first medication for pain treatment did not promote better analgesic effect than the ladder recommended by World Health Organization, with higher incidence of adverse effects.JUSTIFICACIÓN Y OBJETIVOS:los medicamentos usados según la recomendación de la Organización Mundial de la Salud (OMS) no generan alivio del dolor de un grupo de pacientes con dolor oncológico. El objetivo de este estudio fue evaluar el uso de la morfina como primer medicamento para el tratamiento del dolor oncológico moderado en pacientes con enfermedad avanzada y/o metástasis, como opción a las recomendaciones de la escala analgésica preconizada por la OMS.MÉTODO:sesenta pacientes sin terapia con opiáceos, con una edad mayor o igual a los 18 años, fueron distribuidos aleatoriamente en 2 grupos. Los pacientes del G1 recibieron medicamentos según la escala analgésica iniciando el tratamiento con no opiáceo en la primera etapa, opiáceo débil en la segunda y opiáceo potente en la tercera; los del G2 recibieron morfina como primer medicamento analgésico. Fueron evaluadas la eficacia y la tolerabilidad del uso inicial de la morfina cada 2 semanas durante 3 meses.RESULTADOS:los grupos fueron similares en cuanto a los datos demográficos. No hubo diferencia significativa entre los grupos en lo que respecta a la intensidad del dolor, calidad de vida, capacidad física, satisfacción con el tratamiento, necesidad de complementación y dosis de morfina usada. En el G1 hubo una mayor incidencia de náuseas (p = 0,0088), somnolencia (p = 0,0005), estreñimiento (p = 0,0071) y mareos (p = 0,0376) en la segunda consulta, y de somnolencia (p = 0,05) en la tercera.CONCLUSIONES:el uso de la morfina como primer medicamento para el tratamiento del dolor no generó un efecto analgésico mejor que la escala preconizada por la OMS, habiendo una mayor incidencia de efectos adversos.JUSTIFICATIVA E OBJETIVOS:Os medicamentos usados segundo a recomendação da Organização Mundial de Saúde (OMS) não promovem alívio da dor de uma parcela dos pacientes com dor oncológica. O objetivo deste estudo foi avaliar o uso de morfina como primeiro medicamento para o tratamento da dor oncológica moderada, em pacientes com doença avançada e/ou metástases, como opção às recomendações da escada analgésica preconizada pela OMS.MÉTODO:Sessenta pacientes sem terapia com opioide, com idade maior ou igual a 18 anos, foram distribuídos aleatoriamente em dois grupos. Os pacientes do G1 receberam medicamentos segundo a escada analgésica e iniciaram o tratamento com não opioide no primeiro degrau, opioide fraco no segundo e opioide potente no terceiro; os do G2 receberam morfina como primeiro medicamento analgésico. Foram avaliadas a eficácia e a tolerabilidade do uso inicial de morfina, a cada duas semanas durante três meses.RESULTADOS:Os grupos foram semelhantes quanto aos dados demográficos. Não houve diferença significante entre os grupos quanto à intensidade da dor, qualidade de vida, capacidade física, satisfação com o tratamento, necessidade de complementação e dose de morfina usada. No G1 houve maior incidência de náusea (p = 0,0088), sonolência (p = 0,0005), constipação (p = 0,0071) e tontura (p = 0,0376) na segunda consulta e para sonolência (p = 0,05) na terceira.CONCLUSÕES:O uso de morfina como primeiro medicamento para tratamento da dor não promoveu melhor efeito analgésico do que a escada preconizada pela OMS e houve maior incidência de efeitos adversos.Universidade Federal de São Paulo (UNIFESP)UNIFESPSciEL

    Algorithms for zero-dimensional ideals using linear recurrent sequences

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    Inspired by Faug\`ere and Mou's sparse FGLM algorithm, we show how using linear recurrent multi-dimensional sequences can allow one to perform operations such as the primary decomposition of an ideal, by computing the annihilator of one or several such sequences.Comment: LNCS, Computer Algebra in Scientific Computing CASC 201

    Correlation Structures of Correlated Binomial Models and Implied Default Distribution

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    We show how to analyze and interpret the correlation structures, the conditional expectation values and correlation coefficients of exchangeable Bernoulli random variables. We study implied default distributions for the iTraxx-CJ tranches and some popular probabilistic models, including the Gaussian copula model, Beta binomial distribution model and long-range Ising model. We interpret the differences in their profiles in terms of the correlation structures. The implied default distribution has singular correlation structures, reflecting the credit market implications. We point out two possible origins of the singular behavior.Comment: 16 pages, 7 figure

    Dynamic behaviour of the silica-water-bio electrical double layer in the presence of a divalent electrolyte

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    Electronic devices are becoming increasingly used in chemical- and bio-sensing applications and therefore understanding the silica-electrolyte interface at the atomic scale is becoming increasingly important. For example, field-effect biosensors (BioFETs) operate by measuring perturbations in the electric field produced by the electrical double layer due to biomolecules binding on the surface. In this paper, explicit-solvent atomistic calculations of this electric field are presented and the structure and dynamics of the interface are investigated in different ionic strengths using molecular dynamics simulations. Novel results from simulation of the addition of DNA molecules and divalent ions are also presented, the latter of particular importance in both physiological solutions and biosensing experiments. The simulations demonstrated evidence of charge inversion, which is known to occur experimentally for divalent electrolyte systems. A strong interaction between ions and DNA phosphate groups was demonstrated in mixed electrolyte solutions, which are relevant to experimental observations of device sensitivity in the literature. The bound DNA resulted in local changes to the electric field at the surface; however, the spatial- and temporal-mean electric field showed no significant change. This result is explained by strong screening resulting from a combination of strongly polarised water and a compact layer of counterions around the DNA and silica surface. This work suggests that the saturation of the Stern layer is an important factor in determining BioFET response to increased salt concentration and provides novel insight into the interplay between ions and the electrical double layer

    Complex sequencing rules of birdsong can be explained by simple hidden Markov processes

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    Complex sequencing rules observed in birdsongs provide an opportunity to investigate the neural mechanism for generating complex sequential behaviors. To relate the findings from studying birdsongs to other sequential behaviors, it is crucial to characterize the statistical properties of the sequencing rules in birdsongs. However, the properties of the sequencing rules in birdsongs have not yet been fully addressed. In this study, we investigate the statistical propertiesof the complex birdsong of the Bengalese finch (Lonchura striata var. domestica). Based on manual-annotated syllable sequences, we first show that there are significant higher-order context dependencies in Bengalese finch songs, that is, which syllable appears next depends on more than one previous syllable. This property is shared with other complex sequential behaviors. We then analyze acoustic features of the song and show that higher-order context dependencies can be explained using first-order hidden state transition dynamics with redundant hidden states. This model corresponds to hidden Markov models (HMMs), well known statistical models with a large range of application for time series modeling. The song annotation with these models with first-order hidden state dynamics agreed well with manual annotation, the score was comparable to that of a second-order HMM, and surpassed the zeroth-order model (the Gaussian mixture model (GMM)), which does not use context information. Our results imply that the hierarchical representation with hidden state dynamics may underlie the neural implementation for generating complex sequences with higher-order dependencies

    POULTRY FARMING AND LIGHTING: A REVIEW ON THE IMPORTANCE OF LIGHTING IN BROILER CHICKEN AVIARIES

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    ABSTRACT Brazil stands as a significant economic power in agribusiness, particularly in poultry farming. Broiler chicken production has been developing and evolving in the country for many decades. From these advancements, studies have shown that lighting can be directly related to the well-being and development of the birds. Proper lighting programs can enhance the birds' production capacity while providing a pleasant quality of life. This aids in avoiding psychological disturbances caused by poor environmental conditions, such as cannibalism or skeletal malformation. In this context, this paper aims to present some historical data about Brazil and the onset of poultry farming, the relationship between poultry farming and lighting, and some concepts related to lighting
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