9,278 research outputs found
An exact master equation for the system-reservoir dynamics under the strong coupling regime and non-Markovian dynamics
In this paper we present a method to derive an exact master equation for a
bosonic system coupled to a set of other bosonic systems, which plays the role
of the reservoir, under the strong coupling regime, i.e., without resorting to
either the rotating-wave or secular approximations. Working with phase-space
distribution functions, we verify that the dynamics are separated in the
evolution of its center, which follows classical mechanics, and its shape,
which becomes distorted. This is the generalization of a result by Glauber, who
stated that coherent states remain coherent under certain circumstances,
specifically when the rotating-wave approximation and a zero-temperature
reservoir are used. We show that the counter-rotating terms generate
fluctuations that distort the vacuum state, much the same as thermal
fluctuations.Finally, we discuss conditions for non-Markovian dynamics
Semiclassical back reaction around a cosmic dislocation
The energy-momentum vacuum average of a conformally coupled massless scalar
field vibrating around a cosmic dislocation (a cosmic string with a dislocation
along its axis) is taken as source of the linearized semiclassical Einstein
equations. The solution up to first order in the Planck constant is derived.
Motion of a test particle is then discussed, showing that under certain
circumstances a helical-like dragging effect, with no classical analogue around
the cosmic dislocation, is induced by back reaction.Comment: Published version, 4 pages, no figures, REVTeX4 fil
Comportamento produtivo de babacual em um aluviao eutrofico, em Teresina-PI.
bitstream/item/96916/1/PAN210001.pd
Nutritional interventions for heart failure patients who are malnourished or at risk of malnutrition or cachexia: a systematic review and meta-analysis
Malnutrition is common in heart failure (HF), and it is associated with higher hospital readmission and mortality rates. This review aims to answer the question whether nutritional interventions aiming to increase protein and energy intake are effective at improving outcomes for patients with HF who are malnourished or at risk of malnutrition or cachexia. Systematic searches of four databases (Medline, Embase, CINAHL and Cochrane Central Register of Controlled Trials (CENTRAL)) were conducted on 21 June 2019. Randomized controlled trials (RCTs) or other interventional studies using protein or energy supplementation for adult HF patients who are malnourished or at risk of malnutrition or cachexia were included. Two independent reviewers assessed study eligibility and risk of bias. Five studies (four RCTs and one pilot RCT) met the inclusion criteria. The majority of studies were small and of limited quality. The pooled weighted mean difference (WMD) for body weight showed a benefit from the nutritional intervention by 3.83 kg (95% confidence interval (CI) 0.17 to 7.50, P = 0.04) from three trials with no significant benefit for triceps skinfold thickness (WMD = - 2.14 mm, 95% CI - 9.07 to 4.79, P = 0.55) from two trials. The combination of personalized nutrition intervention with conventional treatment led to a decrease in all-cause mortality and hospital readmission in one study. Findings of this review suggest that nutritional interventions could potentially improve outcomes in HF patients who are malnourished or at risk of malnutrition. However, the strength of the evidence is poor, and more robust studies with a larger number of participants are needed
Glicerina bruta em suplementos para bovinos de corte a pasto no período seco.
O objetivo deste trabalho foi avaliar o efeito da substituição do milho pela glicerina bruta (GB) sobre os parâmetros nutricionais e o desempenho de bovinos de corte em pastagem de Urochloa brizantha 'Marandu', no período seco. Para a avaliação dos parâmetros ruminais, foram utilizados cinco bovinos da raça Nelore não fistulados, com peso corporal (PC) inicial de 331,7±29,6 kg, distribuídos em delineamento em quadrado latino 5x5. Para a avaliação do desempenho, foram utilizados 30 bovinos, com PC médio de 312,4±23,3 kg, distribuídos em delineamento inteiramente casualizado. Avaliaram-se suplementos concentrados (20% de proteína bruta) com 0, 33, 66 e 100% de GB em substituição ao milho, fornecidos na quantidade de 4,0 kg por animal por dia. Os consumos de matéria seca (MS) de suplemento, total e de pasto, bem como o de matéria orgânica (MO) digestível, apresentaram comportamento quadrático frente aos níveis de substituição. As digestibilidades aparentes de MS, MO, fibra em detergente neutro e MO digerida, bem como o ganho médio diário, também apresentaram comportamento quadrático. Em suplementos concentrados fornecidos na quantidade de 10g kg-1 de peso corporal, a substituição total do milho pela glicerina bruta reduz o consumo de suplemento e de matéria orgânica digerida, além do desempenho de bovinos de corte em pastejo.Título em inglês: Crude glycerin in supplements for beef cattle at pasture during the dry season
Controle de adultos e ninfas da mosca-branca Bemisia tabaci biótipo B com Chlorantraniliprole + Thiamethoxan.
Neste trabalho foi determinada a eficiência da mistura dos inseticidas Chlorantraniliprole + Thiametoxan em pulverização foliar no controle de ninfas e adultos da mosca-branca Bemisia tabaci Biótipo B no feijoeiro.bitstream/CNPAF-2009-09/28135/1/comt_165.pd
Redução alimentar de Neomegalotomus simplex em sementes de feijão tratadas com óleo de nim.
O objetivo deste trabalho foi avaliar o efeito de diferentes concentrações do óleo de nim sobre a atividade alimentar de adultos de Neomegalotomus simplex
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