165 resultados para Average Time to Signal
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The objective of this study was to evaluate performance and daytime ingestive behavior of 84 Nellore young bulls in the post-weaning phase kept on Brachiaria brizantha cv. Marandu pastures during the dry season. Treatments were protein mineral supplementation (1 g/kg body weight) and protein+energy mineral supplementation (3 g/kg body weight). The experimental area comprised 12 paddocks in a total area of 27.36 ha, divided in two blocks of six paddocks each, having three replications per treatment in each block, with 42 animals/treatment. The data were subjected to variance analysis with repeated measures over time via procedure PROCMIXED of SAS (Statistical Analysis System, version 9.0) and means were compared by the Tukey test at 5% probability. The initial average weight of animals was 204.8 kg; final weights were 260.9 and 276.9 kg for animals that received protein and protein+energy supplement, respectively. The forage availability, sward height and stocking rate values did not differ with supplementation, but they showed difference between the experimental periods. The average time spent grazing during daylight of animals fed protein+energy supplement was shorter as compared with those which consumed protein supplement. Animals kept under the same pasture conditions during the dry season show better performance when they receive protein+energy supplement than protein supplement.
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The aim of this study was to develop a laboratory method for time response evaluation on electronically controlled spray equipment using Programmable Logic Controllers (PLCs). For that purpose, a PLC controlled digital drive inverter was set up to drive an asynchronous electric motor linked to a centrifugal pump on a experimental sprayer equipped with electronic flow control. The PLC was operated via RS232 serial communication from a PC computer. A user program was written to control de motor by adjusting the following system variables, all related to the motor speed: time stopped; ramp up and ramp down times, time running at a given constant speed and ramp down time to stop the motor. This set up was used in conjunction with a data acquisition system to perform laboratory tests with an electronically controlled sprayer. Time response for pressure stabilization was measured while changing the pump speed by +/-20%. The results showed that for a 0.2 s ramp time increasing the motor speed, as an example, an AgLogix Flow Control system (Midwest Technologies Inc.) took 22 s in average to readjust the pressure. When decreasing the motor speed, this time response was down to 8 s. General results also showed that this kind of methodology could make easier the definition of standards for tests on electronically controlled application equipment.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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INTRODUÇÃO: A doença de Parkinson (DP) é caracterizada por uma degeneração progressiva seletiva de neurônios localizados na pars compacta da substância negra. Ela compõe-se por um conjunto de quatro sintomas motores: tremor, rigidez, bradicinesia e instabilidade postural. OBJETIVO: O estudo objetivou investigar os fatores relacionados à queda na percepção da qualidade de vida de indivíduos com DP. MATERIAIS E MÉTODOS: Participaram deste estudo 25 indivíduos com diagnóstico de doença de Parkinson, classificados entre os estágios um e cinco da escala de estadiamento de Hoen e Yahr, tendo a sua qualidade de vida avaliada segundo o Parkinson Disease Questionary-39 (PDQ-39). RESULTADOS: Os 25 indivíduos (12 homens e 13 mulheres) apresentaram idade média de 71,2 ± 8,5 anos, variando entre 53 a 85 anos, e tempo de evolução da doença de 6,54 ± 7,71, variando entre 1 e 39 anos de doença. Verificou-se que as piores percepções sobre a qualidade de vida estão relacionadas ao domínio mobilidade, com média de 55% de comprometimento, e ao domínio atividade de vida diária, com 52,78% de comprometimento. Ficou também constatada uma alta correlação entre o escore total do PDQ-39 com os domínios atividade de vida diária, bem-estar emocional e mobilidade. CONCLUSÕES: A partir dos resultados obtidos, é possível constatar que carências de origem motora associadas aos sinais e sintomas e às complicações secundárias da DP interferem negativamente sobre a percepção da qualidade de vida dos indivíduos.
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Aim. Duplex scanning has been used in the evaluation of the aorta and proximal arteries of the lower extremities, but has limitations in evaluating the arteries of the leg. The utilization of ultrasonographic contrast (USC) may be helpful in improving the quality of the image in these arteries. The objective of the present study was to verify whether the USC increases the diagnostic accuracy of patency of the leg arteries and if it diminishes the time needed to perform duplex scanning.Methods. Twenty patients with critical ischemia (20 lower extremities) were examined by standard duplex scanning, duplex scanning with contrast and digital subtraction arteriography (DSA). The 3 arteries of the leg were divided into 3 segments, for a total of 9 segments per limb. Each segment was evaluated for patency in order to compare the 3 diagnostic methods. Comparison was made between standard duplex scanning and duplex scanning with contrast in terms of quality of the color-coded Doppler signal and of the spectral curve, and also of the time to perform the exams.Results. Duplex scanning with contrast was similar to arteriography in relation to patency diagnosis (p>0.3) and even superior in some of the segments. Standard duplex scanning was inferior to arteriography and to duplex scanning with contrast (p<0.001). There were improvements of 70% in intensity of the color-coded Doppler signal and 76% in the spectral curve after the utilization of contrast. The time necessary to perform the examinations was 23.7 minutes for standard duplex scanning and 16.9 minutes for duplex scanning with contrast (p<0.001).Conclusion. The use of ultrasonographic contrast increased the accuracy of the diagnosis of patency of leg arteries and diminished the time necessary for the execution of duplex scanning.
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Infertility represents one of the main long-term consequences of the chemotherapy used for the adjuvant treatment of breast cancer. Approximately 60-65% of breast cancers express the nuclear hormone receptor in premenopausal women. Adjuvant endocrine therapy is an integral component of care for patients with hormone receptor-positive (HR+) tumours. The GnRH agonist (GnRHa) alone or in combination with tamoxifen produces results at least similar to those obtained with the different chemotherapy protocols in patients with HR+ breast cancer with respect to recurrence-free survival and overall survival. It is time to indicate adjuvant therapy with GnRHa associated with tamoxifen for patients with breast cancer (HR+ tumours) if they want to preserve their reproductive function. The evaluation of ovarian reserve tests: follicle stimulating hormone (FSH), anti-Mullerian hormone (AMH), inhibin B, antral follicle count (AFC) and ovarian volume 6 months, and 1 year after the end of therapy with GnRHa/tamoxifen must be realised. The recurrence-free survival and overall survival should be analysed. The major implication of this hypothesis will be to avoid adjuvant chemotherapy for patients with breast cancer (HR+ tumours) that request fertility preservation. It is expected that ovarian function should not be altered in almost all cases and subsequent pregnancy a real possibility. (C) 2012 Elsevier Ltd. All rights reserved.
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Objetivou-se com a execução deste trabalho avaliar, em nível de campo, o desempenho zootécnico de girinos de rã-touro (Rana catesbeiana) criados em ranários comerciais que utilizam o sistema anfigranja, e simultaneamente estimar os valores de consumo diário de ração para compor uma tabela de referência para a alimentação dos animais. Os resultados encontrados nas unidades de observações monitoradas (aproximadamente 249 mil animais) atingiram os seguintes índices médios: a mortalidade (em %) variou de: 0,7 a 35,2 (média 5,9%); o ganho de peso (g. p/dia): de 0,03 a 0,22 (média 0,11 g/dia); e a conversão alimentar: de 0,92 a 2,75 : 1; (média 1,50 : 1). Comparados com dados preliminares, tais resultados indicam uma significativa otimização dos índices zootécnicos, demonstrando que houve um relativo ganho de produtividade com o aperfeiçoamento das técnicas de manejo implementadas. A redução do valor médio da conversão alimentar aparente foi provocada principalmente pelo adequado uso da tabela de referência, cujos valores foram ratificados durante o trabalho de monitoramento das unidades. Tal tabela possibilita o cálculo da quantidade de alimento a ser oferecido diariamente, baseado nos peso médio dos girinos e na estimativa do percentual de consumo, para temperatura da água entre 18 a 29 graus centígrados, (girinos de 0,1 a 26 gramas de peso médio).
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Objetivou-se com este trabalho avaliar (em nível de campo) o desempenho zootécnico da rã-touro, Rana catesbeiana (Shaw, 1882), criada em ranários comerciais que utilizam o Sistema Anfigranja, e , simultaneamente, estimar os valores de consumo diário de alimento para compor uma tabela de referência para o arraçoamento dos animais. As avaliações demonstraram haver valores de produtividade com grandes variações, de acordo com a capacidade do produtor em assimilar a tecnologia e principalmente manejar os animais de forma padronizada, para atingir o ponto de equilíbrio no fluxo de produção de seu plantel. Os resultados encontrados nas unidades de observação monitoradas (aproximadamente 250 mil animais) atingiram os seguintes índices médios: a mortalidade (em %) 0,5 a 39,5 (média geral 12,0); o ganho de peso (g./dia) 0,4 a 2,5 (média geral 1,2); e a conversão alimentar 0,9 a 2,5 : 1,0 (média geral 1,4 : 1,0). É apresentada uma tabela com os percentuais estimados de consumo de alimento, em função do peso médio dos animais, para o cálculo da quantidade de ração a ser oferecida diariamente.
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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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Previous works from our laboratory have revealed that food restriction (FR) promotes discrete myocardial dysfunction in young rats. We examined the effects of FR on cardiac function, in vivo and in vitro, and ultrastructural changes in the heart of middle-aged rats. Twelve-month-old Wistar- Kyoto rats were fed a control (C) or restricted diet (daily intake reduced to 50% of the control group) for 90 days. Cardiac performance was studied by echocardiogram and in isolated left ventricular (LV) papillary muscle by isometric contraction in basal condition, after calcium chloride (5.2 mM) and beta- adrenergic stimulation with isoproterenol (10(-6) M). FR did not change left ventricular function, but increased time to peak tension, and decreased maximum rate of papillary muscle tension development. Inotropic maneuvers promoted similar effects in both groups. Ultrastructural alterations were seen in most FR rat muscle fibers and included, absence and/or disorganization of myofilaments and Z line, hyper-contracted myofibrils, polymorphic and swollen mitochondria with disorganized cristae, and a great quantity of collagen fibrils. In conclusion, cardiac muscle sensitivity to isoproterenol and elevation of extracellular calcium concentration is preserved in middle-aged FR rats. The intrinsic muscle performance depression might be related to morphological damage.
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Estrous behavior and the estrus-to-ovulation interval are essential for estimating the best time to artificially inseminate cattle. Because these parameters are not well characterized in the Nelore breed (Bos indicus), the main purpose of the this study was to determine the estrus-to-ovulation interval in Nelore heifers and cows with natural estrus or with estrus induced by treatments with PGF2 alpha or norgestomet and estradiol valerate (NEV). The cows and heifers were observed continuously (24 h a day) to determine the onset of estrus and to study estrous behavior in the cows. Ten hours after the start of estrus the ovaries were scanned every 2 h by ultrasonography to monitor the dominant follicle until ovulation. Blood samples were collected periodically to determine progesterone levels by RIA. Administration of PGF2 alpha (2 injections, 11 days apart) did not induce estrus in most Nelore females in spite of the presence of functional CL, indicated by progesterone concentrations above 6.0 ng/ml in 25 of 28 animals. Treatment with NEV induced high sexual receptivity in cows (10/11), but only 66% ovulated. Cows with natural or induced estrus exhibited behavioral estrus of 10.9 +/- 1.4 h, and ovulation occurred 26.6 +/- 0.44 h (n = 26) after the onset of estrus. In most of the cows (53.8%) estrus began at night (between 1801 and 600 h), and 34.6% it started and finished during the night. It is concluded that in Nelore females ovulation occurs approximately 26 h after the onset of estrus. Additionally, estrous behavior is shorter than in European breeds, and there is a high incidence of estrus at night, which makes it difficult to detect and, consequently, impairs Al in Nelore cattle. The observation that a high percentage of Nelore females with an active CL did not respond to usual dosages of PGF2 alpha warrants further investigation. (C) 1998 by Elsevier B.V.
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Food restriction (FR) has been shown to promote myocardial dysfunction in rats. The aim of this study was to verify the participation of calcium and beta-adrenergic system on myocardial mechanical alteration in rats submitted to FR. Myocardial performance was studied in isolated left ventricular papillar muscle from young Wistar-Kyoto rats (WKY) submitted to FR or to control diet. The groups subjected to FR were fed 50% less food than the control group for 90 days. Mechanical function was studied in isometric contraction at post-rest contraction of 30 seconds (PRC), calcium chloride concentration 5.20 mM, and beta-adrenergic stimulation with isoproterenol 10(-6) M. FR decreased the body weight, and left and right ventricular weight. In basal condition (1.25 MM of calcium) time to peak tension (TPT) and time from peak tension to 50% relaxation (RT50) were greater in the FR group. Muscle function was. The same in both PRC groups. TPT decrease in both high calcium groups, more in FR rats; RT50 dropped only in FR animals. TPT decreased in both Isoproterenol groups, more intensely in the FR group. This result suggests that food restriction impairs myocardial performance and these changes may be attributed to alterations in the intracellular calcium cycling and beta-adrenergic system. (C) 2003 Elsevier B.V. All rights reserved.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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The epididymal sperm transit time seems to have an important role in the process of sperm maturation, and it seems that alterations to the transit can harm the process. The aim of the present work was to evaluate the influence of altered sperm transit time through the epididymis on sperm parameters and fertility of rats, as well as the role of testosterone in the alterations. Sprague-Dawley adult male rats were randomly assigned to four different groups and were treated for 12 days: (i) 10 mu g/rat/day DES, to accelerate the transit; (ii) 6.25 mg/kg/day guanethidine sulphate, to delay the transit; (iii) same treatment as group 1, plus androgen supplementation; (iv) control animals received the vehicles. Guanethidine treatment delayed the sperm transit time through the epididymal cauda, provoking increased sperm reserves in this region. Animals exposed to DES showed an acceleration of sperm transit time in the epididymis, and consequently decreased sperm density in both epididymal regions, the caput-corpus and cauda, and diminished sperm motility. In both cases sperm production was not altered. Testosterone supplementation was able to restore the transit time to values close to normality, as they were higher than in the control rats. The same occurred in relation to sperm motility. Rats exposed to DES presented lower fertility after in utero artificial insemination using sperm collected from the proximal cauda epididymis. Therefore, it was concluded that the acceleration of rat sperm transit time appeared to harm normal sperm maturation, thus decreasing sperm quality and fertility capacity, in an androgen-dependent way.