889 resultados para continuous and discrete variables
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Citrus sudden death (CSD) has greatly affected sweet orange cultivars grafted on Rangpur lime in São Paulo and Minas Gerais States, Brazil. To characterize and quantify CSD damage, fruit yield and quality were assessed in each combination of sweet orange cultivar (Hamlin, Pera, Natal, and Valencia), age class (3 to 5, 6 to 10, and 11 to 15 years old), and CSD severity class (0 = no symptom, 1 = initial symptoms, and 2 = severe symptoms). For each combination, 10 trees were harvested and 20 fruit were taken for quality analysis. Damage was characterized by reduc_ tion of: (i) total weight of fruit/tree (36 and 67% for severity class 1 and 2, respectively), (ii) number of fruit/tree (27 and 55%), (iii) fruit size (13 and 25% in diameter and height [stem to styler distance]), (iv) fruit weight (32 and 56%), (v) total soluble solids (TSS)/fruit (18 and 42%), and increase of (vi) Brix (14 and 34%), (vii) acidity (16 and 41%), and (viii) TSS/90-1b. box (21 and 33%). There was no alteration on Brix/acidity ratio and percentage of juice on fruit of affected trees. Sweet orange cultivars did not differ in percentage of reduction or increase of all yield and quality variables, with the exception of Pera, which expressed increases of Brix and acidity. For more severe affected trees, the youngest plants showed a higher reduction in fruit number/tree, whereas plants 6 to 10 years old showed a higher increase in fruit acidity and TSS/box. However, no differences in percentage of reduction or increase for other variables were observed among different age classes. The damage to the above probably was associated with reduced water absorption capacity of CSD-affected trees.
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Avaliaram-se os efeitos da infusão de diferentes doses de lidocaína sobre o ritmo cardíaco, em cães anestesiados com isofluorano que receberam doses crescentes de adrenalina. Foram utilizados 10 cães, cada qual anestesiado quatro vezes, respeitando-se um intervalo de duas semanas. A indução anestésica foi realizada com propofol, 8mg/kg, e a manutenção com isofluorano a 1,5 CAM. Os animais foram distribuídos em quatro grupos, que receberam bolus de lidocaína, 1mg/kg, seguido pela infusão de lidocaína nas taxas de 50μg/kg/h (G50), 100μg/kg/h (G100) e 200μg/kg/h (G200). O grupo-controle (GC) recebeu bolus e infusão de NaCl a 0,9%. As variáveis foram mensuradas 30 minutos após a indução, e em seguida, iniciadas as infusões. Após 10 minutos do princípio dos tratamentos, colheram-se novamente os dados e iniciou-se a infusão de adrenalina, 1μg/kg/min. em intervalos de 10 minutos, realizou-se nova colheita de dados e acrescentou-se 1μg/kg/min na taxa de infusão de adrenalina, até atingir 5μg/kg/min. Comparativamente ao GC, ocorreu redução do aparecimento de batimentos de origem não sinusal e bloqueios atrioventriculares de segundo grau nos grupos tratados com lidocaína. Concluiu-se que a associação de lidocaína à anestesia com isofluorano diminuiu o aparecimento de irregularidades no ritmo cardíaco.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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The aim of study was to investigate if different intake levels of concentrate (supplementation levels) would have an influence on chemical composition, biometric aspects and bone mineral density (BMD) of femurs from Moxoto growing goats in the Brazilian semiarid region. Thirty-two castrated kids (15.69 +/- 0.78 kg initial BW) were used allocated randomly to one of the four levels of supplementation (SL) (treatments groups: 0: 5; 10 and 15 g/kg BW). When the animals of treatment group 15 g/kg BW reached 25 kg BW, the animals in the others treatments groups were also slaughtered. The increase SL resulted in linear increase (P<0.001) in the performance of animals as well as in fresh and dry weight of the femur and decrease of relative weight of the femur. The dry matter contents (g/kg) of femur increased linearly, however, the amounts of MM, ether extract, Ca, P. Mg, Na and K were not affected by the treatments. The values found in this study ranged from 134.84 to 155.90g of Ca, 48.14 to 55.95g of P. 1.69 to 1.87g of Mg, 2.87 to 3.24g of Na and 1.42 to 1.61 g of K/kg of bone in natura for animals with smaller and higher slaughter weight, respectively. The biometric and densitometric variables increased linearly with increasing treatments, except for the thickness of the sponge layer of the proximal and distal epiphysis and BMD measured in the distal epiphysis. The supplementation with concentrate did not affect the chemical composition of the femur, although it has positively influenced the structure and the bone mineral density. A BMD estimated via radiographic bone aluminum equivalent did not have correspondence with bone mineral content measured chemically. (C) 2011 Elsevier BM. All rights reserved.
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Among the several variables that influence timber harvesting is the slope, which influences the productivity of forest machines. In this experiment the harvester was evaluated technically and economically while cutting and processing eucalyptus activity on different slope classes. The technical analysis included a study of time and movements by the method of continuous time; productivity was determined by the volume in cubic meters of wood processing. The economic analysis included the parameters of operational cost, production cost and energy consumption. The analysis of the data showed that productivity decreased according to the increase of the percent slope inclination, resulting in an effective work hour productivity increase from 18.72 to 39.71 m(3)sc, with a mean of operating cost of US$ 78.78 per work hour.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Physical exercise and statins, recommended interventions to dyslipidaemia treatment, are independently related to cardiomyocytes alterations, characterized by miocardic hypertrophy and apoptosis, respectively. Thus, the objective of the present study was to analyze the effects of statin and aerobic physical exercise association in the morphometric parameters of cardiac cell nucleus. 40 male rats adults were divided into four groups: exercised (DE); sedentary (DS), exercised and statin use (DES); sedentary and statin use (DSS). The animals received during the whole experimental period a hiperlipidic diet added 20% of coconut oil and 1.25% of cholesterol; after 30 days of its ingestion, a blood collection was made to verify the dyslipidaemia. Simvastatin (20 mg) was taken five days a week, during eight weeks. During this period, the animals exercised 60 minutes daily in the treadmill. After the last day of the protocol, the cardiac muscle was collected and maintained in liquid nitrogen (-180 degrees C); the cuts were stained by Hematoxilin-Eosin method, and the cardiac fibers were submitted to the nuclear morphometric analyses. The data were analyzed using descriptive analyses, paired T test, Kruskal-Wallis test and Dunn post hoc test; for all analyses, it was adopted p<0.05. It was verified that the group receiving statin presented values statistically significant in comparison to the other groups, in the tridimensional and linear variables. The exercised and statin group, the values obtained in the morphometric analyses were similar to the control group. It is suggested that statins alone can cause alterations in the nucleus of cardiac cells that can be related to apoptosis occurrence and, when exercise is practiced associated to statin administration, the effects of statin can be reduced, what can be related to beneficial adaptations of cardiac mitochondrial in response to physical exercise, turning them more resistant to apoptotic stimuli.
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Delay discounting, one element which underlies decision-making, can be defined as the depreciation of the value of a reward related to the time that it takes to be released. High rates of delay discounting are found in subjects who are willing to forgo greater rewards available only after some length of time and who show a preference for smaller rewards that are available immediately. Widely used as a measure of impulsiveness, delay discounting can be evaluated using experimental tasks. The present review evaluated tasks of delay discounting, their features, measures of evaluation and anomalies, and some variables that can affect delay discounting results and applications in the study of individual and intra-individual differences.
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Most of ontogenetic studies on circadian timing system have been developed on infants, adults and elderly. The puberty has not been a stage of life few studied, except for researches in human adolescents, that presents phase delay in sleep-wake cycle. However, few studies have focused on the basis of this circadian change due to methodological difficulties. Thus, an animal model to study the sleep-wake cycle at puberty is essential. In the common marmoset, a social primate, the circadian activity periodicity stabilizes around 4 months (juvenile stage) and the 8h period component has a seasonal variation. Puberty stage of this species begins near the 8th month of age in males and near the 7th month in females with 7 months of duration. With the aim to characterize the circadian motor activity rhythm during puberty in marmosets (Callithrix jacchus) the motor activity was continuous registered by actiwatches in 6 animals between 5-12 months. Since the social factor influence the behavior of this specie, behavioral observations were realized in 30 minutes windows twice/week to a general evaluation of the influence social interactions dynamic across experiment. Determination of puberty onset was done by fecal progesterone and estrogens in females, and androgens in males. From the analysis of the multiple regression test was selected a model that evaluate age and seasonal variables effect on the activity rhythm according to the higher explanation coefficient. The total activity was the only parameter influenced by age. Moreover, the activity onset was the parameter more explained by the model, and the sunrise was the factor that most influenced it. After the puberty onset, 2 dyads advanced the activity onset. The activity total decreased in 1 dyad and increased in 2 dyads. This increase may be related to the birth of infants in these families. The motor activity circadian component stabilized later in 1 dyad, coinciding with the puberty onset of these animals, while bimodality, caused by the 8 h component, was modulated by seasonality. The agonistic behavior was not evaluated due to reduced number of events. There were changes across ages in affiliative behavior of contact in 1 dyad, grooming done in 1 animal and grooming received in 2 animals. Although there is evidence of puberty effect on the activity motor rhythm, the photoperiodic fluctuations influenced the rhythm. Therefore is not possible to affirm if the puberty modulate the activity rhythm in marmosets
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The rotational motion of an artificial satellite is studied by considering torques produced by gravity gradient and direct solar radiation pressure. A satellite of circular cylinder shape is considered here, and Andoyers variables are used to describe the rotational motion. Expressions for direct solar radiation torque are derived. When the earth's shadow is not considered, an analytical solution is obtained using Lagrange's method of variation of parameters. A semi-analytical procedure is proposed to predict the satellite's attitude under the influence of the earth's shadow. The analytical solution shows that angular variables are linear and periodic functions of time while their conjugates suffer only periodic variations. When compared, numerical and analytical solutions have a good agreement during the time range considered.
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Optimised placement of control and protective devices in distribution networks allows for a better operation and improvement of the reliability indices of the system. Control devices (used to reconfigure the feeders) are placed in distribution networks to obtain an optimal operation strategy to facilitate power supply restoration in the case of a contingency. Protective devices (used to isolate faults) are placed in distribution systems to improve the reliability and continuity of the power supply, significantly reducing the impacts that a fault can have in terms of customer outages, and the time needed for fault location and system restoration. This paper presents a novel technique to optimally place both control and protective devices in the same optimisation process on radial distribution feeders. The problem is modelled through mixed integer non-linear programming (MINLP) with real and binary variables. The reactive tabu search algorithm (RTS) is proposed to solve this problem. Results and optimised strategies for placing control and protective devices considering a practical feeder are presented. (c) 2007 Elsevier B.V. All rights reserved.