864 resultados para withdrawal rates


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Objective To establish the correlation between the bispectral index (BIS) and different rates of infusion of propofol in dogs.Study design Prospective experimental trial.Animals Eight adult dogs weighing 6-20 kg.Methods Eight animals underwent three treatments at intervals of 20 days. Propofol was used for induction of anesthesia (10 mg kg(-1) IV), followed by a continuous rate infusion (CRI) at 0.2 mg kg(-1) minute(-1) (P2), 0.4 mg kg(-1) minute(-1) (P4) or 0.8 mg kg(-1) minute(-1) (P8) for 55 minutes. The BIS values were measured at 10, 20, 30, 40, and 50 minutes (T10, T20, T30, T40, and T50, respectively) after the CRI of propofol was started. Numeric data were submitted to analysis of variance followed by Tukey test (p < 0.05).Results The BIS differed significantly among groups at T40, when P8 was lower than P2 and P4. At T50, P8 was lower than P2. The electromyographic activity (EMG) in P2 and P4 was higher than P8 at T40 and T50.Conclusion An increase in propofol infusion rates decreases the BIS values and EMG.

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A reciclagem agrícola do lodo de esgoto tem provocado o acúmulo de metais pesados no solo e na água, podendo atingir níveis tóxicos e causar danos às plantas cultivadas, aos animais e ao homem, por meio da cadeia trófica. Neste intuito foi desenvolvido o presente experimento, em condições de campo, entre 2000 e 2002, onde foram avaliados os efeitos da aplicação de lodo de esgoto por dois anos, sobre a extração de metais de transição (essenciais e não) pelo extrator DTPA em um Latossolo Vermelho distrófico (LVd) de textura média. As concentrações dos elementos metálicos: Mn, Fe, Cd, Ni, Co, Pb e Cr não foram detectados pelo método da absorção atômica na solução obtida com o extrator DTPA. A aplicação de lodo de esgoto causou inicialmente pequena elevação no pH do solo, posteriormente a diminuição do mesmo, e manteve-se próximo ao original. Foi possível concluir que, com a aplicação consecutiva do lodo, os teores extraíveis de Fe e Mn nas amostras de solos aumentaram gradativamente nos dois anos agrícolas, com as doses do lodo de esgoto aplicado, época de amostragens, e foram superiores ao tratamento testemunha. O extrator apresentou capacidade restrita para avaliação da fitodisponibilidade dos metais pesados decorrentes das baixas concentrações nas amostras de solo.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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The present study investigated how the timing of the administration of estradiol benzoate (EB) impacted the synchronization of ovulation in fixed-time artificial insemination protocols of cattle. To accomplish this, two experiments were conducted, with EB injection occurring at different times: at withdrawal of the progesterone-releasing (N) intravaginal device or 24 h later. The effectiveness of these times was compared by examining ovarian follicular dynamics (Experiment 1, n = 30) and conception rates (Experiment 2, n = 504). In Experiment 1, follicular dynamics was performed in 30 Nelore cows (Bos indicus) allocated into two groups. on a random day of the estrous cycle (Day 0), both groups received 2 mg of EB i.m. and a P4-releasing intravaginal device, which was removed on Day 8, when 400 IU of eCG and 150 mu g of PGF were administered. The control group (G-EB9; n = 15) received 1 mg of EB on Day 9, while Group EB8 (G-EB8; n = 15) received the same dose a day earlier. Ovarian ultrasonographic evaluations were performed every 8 h after device removal until ovulation. The timing of EB administration (Day 8 compared with Day 9) did affect the interval between P4 device removal to ovulation (59.4 +/- 2.0 h compared with 69.3 +/- 1.7 h) and maximum diameter of dominant (1.54 +/- 0.06 a cm compared with 1.71 +/- 0.05 b cm, P = 0.03) and ovulatory (1.46 +/- 0.05 a cm compared with 1.58 +/- 0.04 b cm, P < 0.01) follicles. In Experiment 2,504 suckling cows received the same treatment described in Experiment 1, but insemination was performed as follows: Group EB8-AI48h (G-EB8-AI48h; n = 119) and Group EB8-AI54h (G-EB8-AI54h; n = 134) received 1 mg of EB on Day 8 and FrAI was performed, respectively, 48 or 54 h after P4 device removal. Group EB9-AI48h (G-EB9-AI48h; n = 126) and Group EB9-AI54h (G-EB9-AI54h n = 125) received the same treatments and underwent the same FTAI protocols as G-EB8-AI48h and G-EB8-AI54h, respectively; however, EB was administered on Day 9. Conception rates were greater (P < 0.05) in G-EB9-AI54h 163.2% (79/125) a], G-EB9-AI48h [58.7% (74/126) a] and G-EB8-AI48h [58.8% (70/119) a] than in G-EB8-AI54h [34.3% (46/134) b]. We concluded that when EB administration occurred at device withdrawal (D8), the interval to ovulation shortened and dominant and ovulatory follicle diameters decreased. Furthermore, when EB treatment was performed 24 h after device removal, FTAI conducted at either 48 or 54 h resulted in similar conception rates. However, EB treatment on the same day as device withdrawal resulted in a lesser conception rate when FTAI was conducted 54 h after device removal. (C) 2007 Elsevier B.V. All rights reserved.

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Background: In bovines, more efficient management practices are important for maximizing profitability. In order to increase the pregnancy rates in artificial insemination (AI) programs, several hormonal protocols were developed to synchronize the follicular wave and the moment of ovulation in beef and dairy cattle. In dairy cattle, detection of estrus can be difficult due to a number of factors including the incidence of silent estrus. Hormonal treatments designed to control both luteal and follicular function has permitting efficient synchronizations of time of ovulation. Thus, the AI can be performed in a large number of animals on a fixed schedule without the need for detection of estrus. Using these management techniques, the fixed-time artificial insemination (TAI) can overcome the problem of accurate estrus detection and help in reducing the incidence of repeat breeding. In addition, with TAI in cattle operations, it is possible to facilitate management practices and commercialization, and to reduce the time and semen wasting with animals inseminated at incorrect times. The investigation of practical and efficient TAI protocols is important for reducing the labor and animal handling of TAI in dairy cattle, as well as for increasing the profitability of the cattle management system. This study was carried out in order to investigate the effectiveness of TAI in dairy heifers treated with a practical progesterone-based protocol.Materials, Methods & Results: This experiment was conducted at the university farm located in southwestern Brazil, during May 2009. Thirty-nine cycling crossbred dairy heifers were employed in this study. All animals received a single intramuscular injection of estradiol benzoate and intravaginal progesterone releasing device in a random stage of the estrous cycle (Day 0). on day 7 the animals were treated with PGF2a analogue and on day 9 the device was removed. Forty-eight hours after the device removal (day 11) a synthetic analogue of GnRH was administered and the animals were fixed-time artificially inseminated at the time of GnRH injection. The inseminations were performed using four different batches from the same Holstein bull. Among the heifers that were synchronized (87.2%), 30.8% ovulated until 24 h after TAI and 56.4% ovulated between 24 and 32 h after TAI. The conception rate was 61.5%. No effects of ovulation time in conception rates were detected. The conception rate from heifers that ovulated until 24 h after TAI was 58.3% and from heifers that ovulated between 24 and 32 h after TAI was 77.3%. The mean of ovulatory follicle in heifers that ovulated until 24 h was 14.3 mm and in heifers that ovulated between 24 and 32 h was 11.9 mm.Discussion: Taking together, the findings of the present study, along with those of others, emphasize the concept that development of practical methods for TAI offers significant advantages to dairy producers if conception rates are close or greater to those obtained after breeding at detected estrus. Thus, the results of the present study reinforce the possibility of making dairy cattle production more cost-effective using TAI. In conclusion, with the progesterone-based TAI protocol of the present experiment all synchronized animals ovulated up to 32 h after GnRH+TAI and no effects of ovulation time related to conception rate was detected. The exogenous control of luteal and follicular development facilitated the reproductive management and animal handling. Also, inseminating the heifers at the moment of GnRH injection in a progesterone-based TAI protocol is a practical strategy and provided satisfactory results regarding ovulation and conception rates in dairy heifers.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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O N é o nutriente que proporciona as maiores respostas no crescimento das gramas, e a adubação nitrogenada adequada pode proporcionar a formação do tapete com boa qualidade em menor tempo. Neste trabalho, objetivou-se avaliar a influência da adubação nitrogenada na produção e qualidade de tapetes de grama-bermuda. O experimento foi instalado e conduzido em área de produção comercial de grama, localizada na cidade de Capela do Alto, SP. A grama utilizada foi a Cynodon dactylon (Pers) L., conhecida como grama-bermuda. O delineamento experimental utilizado foi o de blocos casualizados, com cinco tratamentos e quatro repetições. Os tratamentos foram constituídos por cinco doses de N: 0, 150, 300, 450 e 600 kg ha-1. O aumento das doses de N aumentou a taxa de cobertura do solo pela gramabermuda, reduzindo o tempo para formação do tapete. O máximo acúmulo de matéria seca de rizomas + estolões + raízes foi proporcionado pela dose de 354 kg ha-1 de N, e a resistência dos tapetes, pela dose de 365 kg ha-1 de N. Doses de N entre 354 e 365 kg ha-1, aumentaram a resistência dos tapetes e, com isso, a capacidade deles serem manuseados após a colheita, podendo promover assim maior rendimento da área.

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Cation mobility in acidic soils with low organic-matter contents depends not only on sorption intensity but also on the solubility of the species present in soil solution. In general, the following leaching gradient is observed: potassium (K+) magnesium (Mg2+) calcium (Ca2+) aluminum (Al3+). To minimize nutrient losses and ameliorate the subsoil, soil solution must be changed, favoring higher mobility of M2+ (metal ions) forms. This would be theoretically possible if plant residues were kept on the soil surface. An experiment was conducted in pots containing a Distroferric Red Latosol, with soil solution extractors installed at two depths. Pearl millet, black oat, and oilseed radish residues were laid on the soil surface, and nitrogen (as ammonium nitrate) was applied at rates ranging from 0 to 150mgkg-1. Corn was grown for 52 days. Except for K+ and ammonium (NH4 +), nitrogen rates and plant residues had little effect upon the concentrations and forms of the elements in the soil solution. Presence of cover crop residues on soil surface decreased the effect of nitrogen fertilizer on Ca leaching. More than 90% of the Ca2+, Mg2+, and K+ were found as free ions. The Al3+ was almost totally complexed as Al(OH3)0. Nitrogen application increased the concentrations of almost all the ions in soil solution, including Al3+, although there was no modification in the leaching gradient.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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No Brasil não existem registros de respostas de adubação com boro para a cultura do triticale, sendo a ação deste nutriente uma incógnita, tanto em relação a deficiência quanto a toxidez, causas que levam a redução de produtividade. O objetivo deste trabalho foi avaliar a resposta do triticale a diferentes níveis de boro em comparação com o trigo (Triticum aestivum). Utilizou-se um Latossolo Vermelho distrófico com teor inicial de boro de 0,08 mg dm-3. O delineamento foi um fatorial 4 ´ 4, distribuído em blocos casualizados, com quatro repetições, quatro níveis de boro: 0; 0,62; 1,24 e 1,86 mg dm-3 de B e três cultivares de triticale, IAC 3, BR 4 e BR 53, mais um cultivar de trigo, IAPAR 38, para comparação. Cada cultivar respondeu de forma diferente com relação às variáveis estudadas em função da aplicação de diferentes níveis de boro. O trigo (IAPAR 38) apresenta maior eficiência na absorção de boro. A cultivar de triticale mais responsiva quanto à absorção foi a IAC 3, que apresentou característica semelhante ao trigo, seguida da cultivar BR 4, demonstrando serem cultivares tolerantes a maiores níveis de boro no solo. Para a BR 53, não ocorreu efeito para absorção, com a cultivar apresentando sensibilidade à toxidez de boro. A eficiência de absorção é diferenciada para cada genótipo possibilitando a escolha e utilização de plantas que possuam maior adaptação ao meio.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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This dissertation proposes studying the issue of withdrawal undergraduate in physics at the Instituto Federal de Educação, Ciência e Tecnologia do Rio Grande do Norte (IFRN) and collaborate with suggestions for dealing with this problem. The first chapter begins with an overview of two significant problems in the Brazilian educational system: the high dropout rates in degrees in physics and the lack of teachers with specific training in this science. Then, we discuss the relevance of this research to the area of physics teaching, as well as justify its completion as part of a professional master's degree. After, we present a proper definition for the term withdrawal, which is based on the existing problem in the IFRN. And, in the same chapter, we explicitly the focus, the objectives and the methodological aspects of this work. The results obtained in our investigation are presented in next four chapters. In the second chapter of this dissertation, we present: a brief history of the creation of IFRN degree in physics, the functioning of this course and the foundation of classrooms 2004.2 and 2006.1. We also show a kind of map of the withdrawal of the groups investigated (the dropout rate was 84.4% in both groups) and an analysis of the relationship between the curricula of each of them and the number of dropouts. In the third chapter, we display a descriptive statistics of the students which dropout and found that the largest dropout occurred with students who are women, married, parents of one kid; workers, joined with a minimum age of 23 years and completed high school at least 6 years. Then in the fourth chapter, we reveal and discuss the students' reports on the causes of their dropout. From the data presented, we can say that the answer to the question "What was the main reason for your dropout?" Is mainly in personal injury claims: another option for upper-level course and lack of time to devote to the course. In the fifth chapter, we show the results related to teacher s opinions about the phenomenon in question. We detected three main causes for the abandonment, according to teachers: the lack of dedication, the lack of interest and lack of integration in the course. In the sixth and final chapter, we discuss the results and present our conclusion and the proposed report - the product of this dissertation, presented as Annex. This report contains mainly suggestions for curricular and institutional actions that can contribute to reducing the dropout degree in Physics in the IFRN. The main actions suggested are: implementation of the curriculum in disciplines, implementation of programs or actions to combat this poor content of basic training, implementation of specific programs or actions for the student worker, and dissemination of IFRN degree in physics in schools through seminars or workshops