Este trabalho apresenta estratégias de controle para a sincronização de dois sistemas não-lineares do tipo Lur'e sob controle saturante. O objetivo no uso de controlador e para que os estados de um sistema escravo sigam a referência dos estados do sistema mestre. Resultados teóricos para a síntese de controladores são propostos considerando diferentes hipóteses sobre a não-linearidade do sistema Lur'e. Primeiramente esta e tratada como uma função genérica que satisfaz globalmente uma condição de setor, enquanto que posteriormente assume-se que a função não-linear e uma função linear por partes e um modelo equivalente baseado em funções saturação e empregado para descrever os efeitos da mesma no comportamento dinâmico do sistema. São considerados, ainda, duas estrat egias de controle: realimentação estática dos estados dos sistemas e realimentação dinâmica da saída dos sistemas, incluindo neste ultimo caso elementos referentes as não-linearidades inerentes do sistema Lur'e e um elemento anti-windup. O projeto dos parâmetros de cada controlador e feito através de problemas de otimização convexa com restrições na forma de desigualdades matriciais lineares (LMI s) tendo como objetivo maximizar o conjunto de estados inicias nos quais a sincronização e assegurada. A formulação dos problemas de otimização e obtida através de inequações matriciais lineares, utilizando-se a teoria de estabilidade de Lyapunov juntamente com métodos baseados em condições de setor para assegurar a convergência assintótica do erro de sincronização para zero, i.e. garantir que os estados do sistema mestre são seguidos pelos do escravo. Os métodos propostos são ilustrados por meio de exemplos numéricos tendo como objetivo a sincronização de dois circuitos de Chua. / This work presents control strategies for the synchronization of two nonlinear Lur'e systems subject to control saturation. The objective of the use of controllers is so that the states of a slave system follow the reference of the states of the master system. Theoretical results for the synthesis of controllers are proposed considering di erent hypothesis about the nonlinearity of the Lur'e system. Initially it is considered as being a generic function that satis es globally a sector condition, while afterwards it is assumed that the non-linear function is a piecewise-linear function and an equivalent saturation function model is employed in order to describe its effect on the system's dynamic behaviour. Two controller strategies are considered: a static feedback of the system's states and a dynamic feedback of the system's output, coupled, in the last case, with elements based on the system's non-linearities and an anti-windup element is considered. The design of the parameters of each controller is generated by convex optimization problems with restrictions in the form of linear matriz inequalities (LMI) having as objective maximizing the set of initial conditions for which synchronization is guaranteed. The optimization problems are formulated by the means of linear matrix inequalities based on Lyapunov's stability theory and a sector-based approach to ensure null synchronization error, i.e. to ensure the local asymptotic convergence of the slave state to the master one. The proposed methods are illustrated by numerical examples with the objective of the synchronization of two Chua's circuits.

Two-echelon vehicle routing problems which contain synchronization between vehicles can be deeply impacted by time uncertainty, because one vehicle's delay can propagate to other vehicles. In this paper, we evaluate the deterministic solution of such a problem based on simulated travel time scenarios. The information obtained by simulation is incorporated in the optimization procedure iteratively. Computational results show that the degree of synchronization in an instance is directly correlated with the potential improvements by reoptimization. We present findings on the number of travel time scenarios required to obtain a representative picture of the stochastic solutions. In addition, we demonstrate that time dependent travel times can be aggregated on a city-wide level and linearized as a function of free flow times without major loss of reliability.

A distribuição de sinais de tempo é um fator essencial em muitas aplicações de engenharia como, por exemplo, redes de telecomunicações, circuitos digitais integrados e sistemas de automação. Nas últimas décadas essa tarefa foi realizada, predominantemente, com redes mestre-escravo nas quais existem osciladores de referência que distribuem o sinal de tempo para osciladores escravos (PLLs) construídos para extrair a base de tempo a partir do sinal da linha. Recentemente, entretanto, o surgimento de redes de comunicação wire-less com conectividade dinâmica e o aumento dos tamanhos e das freqüências de operação dos circuitos digitais integrados indicam a necessidade de utilização de estratégias de distribuição de sinais de tempo baseadas em redes mutuamente conectadas. Nesse trabalho são estudadas redes mutuamente conectadas de PLLs para a determinação de condições para a obtenção do sincronismo de redes desse tipo em função dos parâmetros individuais dos nós e da conectividade da rede. Determinou-se também, através de simulações numéricas, a validade dos resultados analíticos obtidos. Finalmente foi estabelecido um método, baseado em algoritmos evolutivos, para a otimização dos parâmetros da rede considerando objetivos de robustez e capacidade de rejeição de ruídos na rede. / Clock-distribution is an essential feature in many engineering applications as, for example, telecommunications networks and digital integrated circuits. In the last few decades this problem was predominantly addressed using master-slave strategies. In this type of strategy there are precise reference oscillators in the network called masters and their signals are distributed in the network, other oscillators called slaves (PLLs) extract the time basis from the line signals. Recently the development of wireless communication networks and the increasing size of digital integrated circuits and their rising operation frequencies indicate the need for the use of mutually-connected networks for the issue of clock-distribution. In this work mutually-connected networks of PLLs are studied in order to obtain conditions for the acquisition of a synchronous state for the network concerning the node parameters and the connection pattern of the network. Furthermore, numerical experiments were conducted to validate analytic results. Finally, a method is proposed, based on evolutionary algorithms, for the optimization of the network parameters considering the robustness and the ability to reject noise in the network as objectives.

Na década de 60, começaram a ser utilizadas técnicas e sincronização do estro, e durante os últimos trinta anos tem sido despertado o interesse do desenvolvimento de métodos para sincronizar o estro de ovelhas. Na maioria das vezes a IA está associada à um protocolo de sincronização do estro podendo assim ser realizada a Inseminação Artificial em Tempo Fixo (IATF). Três experimentos foram realizados com objetivo de avaliar a influência do efeito macho e tipos de rufião, reutilização do dispositivo e o método de inseminação utilizado, na sincronização do estro através do uso de dispositivos intra-vaginais (CIDR®- Control Internal Drog Release), associado com a aplicação intramuscular de eCG e PGF2 , sobre a taxa detecção e tempo médio para aparecimento do estro, taxa de prenhez na IATF e no primeiro estro após a sincronização. Exp. I: Foram utilizadas 270 ovelhas, separadas em três tratamentos: SM = (controle) sem rufiões; DL= recebeu rufiões com Desvio lateral peniano e o VS= recebeu rufiões vasectomizados. Os tratamentos foram submetidos ao mesmo protocolo, CIDR® por 7d, aplicação de 300UI de eCG e 6,71 mg de Dinoprost trometamina, na retirada do CIDR. As ovelhas foram submetidas a IATF pelo método transcervical em 55h após a retirada do CIDR. EXP.II: Foram utilizadas 275 ovelhas, divididas em 4 tratamentos: 7N= 7d com CIDR novo; 7U= 7d com CIDR já usado por 7d; 11N= 11d com CIDR novo; 11U= 11d com CIDR já usado por 7d. No dia da retirada do CIDR (D7 ou D11) foi realizada a aplicação de 300 UI de eCG e 6,71 mg de Dinoprost trometamina. As ovelhas foram submetidas a IATF pelo método transcervical, 49h após a retirada do CIDR. Exp.III: Foram utilizadas 247 ovelhas, divididas em 4 tratamentos: MN= as ovelhas foram sincronizadas e submetidas a monta natural com carneiros; IATF = as ovelhas foram submetidas a IATF por laparoscopia 48h após a retirada do CIDR; IATF+GnRH= as ovelhas foram submetidas a IATF por laparoscopia + 0,05 mg de Gonadorelina, quando 50% das ovelhas apresentaram sinais de estro; IA= as ovelhas foram inseminadas por laparoscopia no sistema AM/PM, 12h após o início dos sinais de estro. Todos os tratamentos foram submetidos ao mesmo protocolo, CIDR por 11 dias, aplicação de 300UI de eCG e 6,31 mg de Dinoprost trometamina, na retirada do CIDR. Nos experimentos I e II as ovelhas foram submetidas ao repasse com carneiros por 20 dias. O delineamento utilizado foi de blocos incompletos ao acaso, analisados pelo teste do Qui-quadrado e Tukey (estro). A taxa de detecção de estro no tratamento IATF (exp. III) foi de 59,7% sendo menor que os demais tratamentos (P<0,05). A taxa de prenhez da sincronização do tratamento MN (61,1%), foi maior (P<0,05) que os tratamentos IATF e IATF+GnRH. A inseminação artificial transcervical apresentou resultados médios que variaram de 21 a 35% e não apresentaram diferença (P>0,05). O efeito macho e o tipo de macho não apresentaram diferença na IATF. O protocolo de 11 dias, mostrou-se eficiente em induzir o estro em 79% das ovelhas sincronizadas. A IA realizada 12h após o estro propiciou, índice de prenhez semelhante à monta natural, proveniente do estro sincronizado. / In the 60s, estrus synchronization techniques began to be used, and during the last 30 years has attracted the interest of developing new methods to synchronize estrus in ewes. Three experiments were performed to determine: I) influence of male effect and type of teaser; II) Effect of new and used CIDR® (Control Internal Drug Release) with different time of implant; III) Different time to perform IA after CIDR removal and comparison of laparoscopy method with natural breed, on heat detection and onset of estrus and pregnancy rate of ewes. Exp. I: 270 ewes were used, divided into three treatments: SM = (control) without teaser; DL = teaser with lateral penis deviation and VS = vasectomized teaser. All ewes were subjected to the same protocol: CIDR® for 7 days and received im. 300UI of eCG plus 6.71 mg tromethamine dinoprost at CIDR withdrawal. Ewes were artificially inseminated by transcervical method, 55h after CIDR removal. There was no difference on onset of estrus for LD (55.7%) and VS (50.5%). Similarly, the distribution of estrus was similar (P>0.05) between treatments, where the averages were of 45:01 ± 14:30 h for LD 12:10 h and 44:00 ± 12:10h for VS. Pregnancy rate did not differ (P> 0.05) among treatments and was 34.0, 34.4 and 35.0% for LD, VS and SM, respectively. The male effect showed no influence on pregnancy rate when fixed-time artificial insemination was used. EXP.II: 275 ewes were used and divided into 4 treatments: 7N = 7d with new CIDR; 7U = 7d with already used CIDR for 7d; 11N = 11d with new CIDR; 11U = 11d with CIDR already used for 7d. On the withdrawal of the CIDR (D7 or D11) ewes received im. 300IU of eCG plus 6.71 mg tromethamine dinoprost at the time of CIDR removal. Ewes were submitted to FTAI, using the transcervical method, 49h after CIDR withdrawal. Total pregnancy rate in treatment 11N was higher (86.6%, P = 0.03) as compared with treatment 7U (71.4%). The protocols for estrus synchronization of 7 and 11d were effective in inducing the expression of estrus. The reuse of CIDR did not influence the rate of onset and average time to onset of estrus and pregnancy rate in the FTAI. Exp.III: 247 ewes were used and divided in four treatments: MN = ewes were synchronized and exposed to males during 20d; IATF = ewes were synchronized and inseminated by laparoscopy 48h after CIDR removal; AITF+GnRH= ewes were synchronized and inseminated by laparoscopy using 0.05 mg gonadorelin, when 50% of the ewes showed signs of estrus; AI = ewes received im. 300IU of eCG plus 6.71 mg tromethamine dinoprost at the time of CIDR removal and were inseminated by laparoscopy, 12h after the onset of signs of estrus. All treatments were subjected to the same protocol: CIDR for 11 days, intramuscular injection of 300UI of eCG plus 6.31 mg tromethamine dinoprost at CIDR removal. In all experiments ewes were exposed to rams (natural breeding), 10 days after FTAI. The experimental design was an incomplete randomized block, analyzed by chi- square and Tukey (estrus). The rate of detection of estrus in the treatment AITF (exp.III) was 59.7%, being lower than the other treatments (P <0.05). The pregnancy rate of the synchronization treatment MN (61.1%) was higher (P <0.05) that the treatments AITF and AITF+GnRH.Transcervical artificial insemination had average results that ranged from 21 to 35% and showed no difference (P> 0.05). The purpose and type of ram showed no difference in the AITF. The protocol of 11d, was effective in inducing estrus in the 79% of ewes synchronized. The IA conducted 12h after estrus provided, similar to pregnancy rate of natural builders, after the synchronization of estrus.

"Faster, higher, stronger"---the Olympic motto is being pursued and practised in the design of broadband wireless communication systems. Motivated by the huge demands for fast and reliable communications over wireless channels, broadband communication systems are required to provide faster (low-complexity) data processing, higher data throughput and stronger (lower error rate) performance. In practice, however, broadband communication systems must cope with critical performance-limiting challenges that include time- and frequency-selective fading channels, noise, inter-symbol interference (ISI), intercarrier interference (ICI) as well as power and bandwidth constraints. To address these challenges, this thesis investigates several physical layer aspects of broadband wireless communication systems. / Incorporating OFDM into multiple-input multiple-output (MIMO) system, MIMO-OFDM has been shown to provide larger channel capacity and greater diversity gain. However, current coding schemes for MIMO-OFDM are either space-time coded (STC) OFDM without the guarantee of full diversity gains or space-frequency coding (SFC) with a greater loss of data rate. Furthermore, most existing STC and SFC have focused on quasi-static fading which is not practical for broadband wireless communications. When multi-band OFDM (MB-OFDM) is applied to ultra-wide band (UWB) communications, a high diversity can be obtained, but in the expense of a much lower (close to half) data rate. To address the limitations of existing coding schemes for broadband wireless communication systems, this thesis: (i) proposes a space-time-frequency coding (STFC) that can achieve maximum diversity and maximum symbol rate transmission over MIMO block-fading channels; (ii) derives a high-rate full-diversity SFC from STFC tailored for frequency-selective fading channels; and (iii) proposes a high-rate high-diversity algebraic time-frequency coding (ATFC) for MB-OFDM system. / Orthogonal frequency division multiplexing (OFDM) is an effective technique to eliminate ISI in broadband wireless communications. This thesis studies the problem of training-based OFDM channel estimation and proposes a training method that minimizes the number of pilots employed to achieve a desired bit error rate (BER) performance. A clustered pilot pattern is further proposed to enhance the BER performance. Focusing on OFDM frequency synchronization, this thesis also proposes a clustered pilot tones placement and a novel pilot sequence design for carrier frequency offset (CFO) compensation. The analytical and simulation results show that the root mean square error (RMSE) of the CFO estimate can be greatly reduced. / Zhang Wei. / "July 2005." / Adviser: Pak-Chung Ching. / Source: Dissertation Abstracts International, Volume: 67-01, Section: B, page: 0461. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (p. 126-143). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.

Submitted by (lucia.rodrigues@ufrpe.br) on 2017-02-08T12:21:58Z No. of bitstreams: 1 Daniel de Castro Burgos.pdf: 962079 bytes, checksum: 7910c72572139941c836e667e046d328 (MD5) / Made available in DSpace on 2017-02-08T12:21:58Z (GMT). No. of bitstreams: 1 Daniel de Castro Burgos.pdf: 962079 bytes, checksum: 7910c72572139941c836e667e046d328 (MD5) Previous issue date: 2012-02-16 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The objective of this experiment was to compare the results of the pregnancy obtained by the association of conventional Artificial Insemination (AI) with synchronized estrus together with GnRH in TAI with those of classical TAI in zebu cows. A total of 677 cows were synchronized with a progesterone vaginal device (P4) and 2 mg of estradiol benzoate (EB) on D1, D7 all cows received 530 μg of PGF2α and D9 implants were removed and all animals received 400 IU of eCG and were evaluated in three experiments divided as follows. In first experiment, 190 cows, without temporarily calf weaning and after removal of devices were divided into three groups: control group called EC received 0.4 mg of estradiol cypionate (EC) and TAI were inseminated 48 hours after removal of devices. The second and third groups did not receive ovulation inductor in removal of devices and were named ESTRUS PLUS GnRH 48 HOURS and ESTRUS PLUS GnRH 54 HOURS. These cows were observed for onset of estrus four times (12, 24, 36 and 48 hours) and those that showed estrus during this period were inseminated by the AM / PM method where estrus in the morning AI late afternoon and estrus in the afternoon with AI on the morning of next day; cows who have not appearing in estrus during this period of 48 hours after devices were removed, received 25 μg of GnRH and were inseminated immediately in the group ESTRUS PLUS GnRH 48 HOURS and 6 hours after application of GnRH cows from ESTRUS PLUS GnRH 54 HOURS were inseminated. In the 2nd experiment 242 cows were subjected to similar protocol, but was held temporarily weaned calves after removal of the implants. At the 3rd experiment 245 cows were subjected to two experimental protocols but using P4 devices previously used. Cows were examined by 5 MHz transrectal ultrasonography 45 days after insemination to detect pregnancy in experiments 1 and 2 and 35 days in experiment 3. In experiment 1, cows received the following pregnancy rates: group EC 58.18%, group ESTRUS PLUS GnRH 48 HOURS 56.21% and group ESTRUS PLUS GnRH 54 HOURS 61.97%. In experiment 2 pregnancy rates were: group EC 57.83%, group ESTRUS PLUS GnRH 48 HOURS 57.50% and group ESTRUS PLUS GnRH 54 HOURS 53.16%. In experiment 3 pregnancy rates were: group EC 57.14%, group ESTRUS PLUS GnRH 48 HOURS 56.10% and group ESTRUS PLUS GnRH 54 HOURS 54.43%. No significant difference were seen (p > 0,05) between the groups. In spite of the protocols showing equivalent results, its costs and labor hamper its use, and the use of classic TAI is simpler and more economically viable. / O objetivo deste experimento foi comparar os resultados de prenhez da associação de Inseminação Artificial (IA) convencional com estro sincronizado acompanhado de IATF utilizando GnRH com os da IATF clássica em vacas azebuadas. Um total de 677 vacas foram sincronizadas com dispositivo de progesterona (P4) e 2 mg de benzoato de estradiol (BE) no D1, no D7 todas receberam 530 μg de PGF2α e no D9 foram retirados os implantes e todos os animais receberam 400 UI de eCG e foram avaliadas em três experimentos divididos da seguinte forma. No 1º experimento 190 vacas, conduzidas sem apartação temporária dos bezerros após a retirada dos dispositivos, foram divididas em três grupos: O grupo controle chamado de CE recebeu 0,4 mg de cipionato de estradiol (CE) e foram inseminadas na IATF 48 horas após a retirada dos dispositivos. O segundo e o terceiro grupos não receberam indutor de ovulação na retirada dos dispositivos e foram chamados de estro mais GnRH 48 horas e estro mais GnRH 54 horas. Essas vacas foram observadas para apresentação de estro por quatro vezes (12, 24, 36 e 48 horas) e as que apresentaram estro neste período foram inseminadas pelo método AM/PM com estro pela manhã inseminação a tarde e estro pela tarde com inseminação na manhã do dia seguinte; as vacas que não apresentaram estro neste período receberam 48 horas após a retirada dos dispositivos, aplicação de 25 μg de GnRH e foram inseminadas imediatamente no grupo estro mais GnRH 48 horas e após 6 horas da aplicação do GnRH foram inseminadas as vacas do lote estro mais GnRH 54 horas. No 2º experimento 242 vacas foram submetidas a protocolo semelhante, porém realizou-se o desmame temporário dos bezerros após a retirada dos implantes. No 3º experimento 245 vacas foram submetidas ao protocolo do experimento 2 porém utilizando dispositivos de P4 anteriormente utilizados. As vacas foram examinadas por ultrasonografia transretal de 5 MHz em 45 dias após as inseminações para detecção de prenhez nos experimentos 1 e 2 e 35 dias no experimento 3. No experimento 1 as vacas obtiveram as seguintes taxas de prenhez: grupo CE 58,18%; grupo estro mais GnRH 48 horas 56,21% e grupo estro mais GnRH 54 horas 61,97%. No experimento 2 os números de gestação foram: grupo CE 57,83%; grupo estro mais GnRH 48 horas 57,50% e grupo estro mais GnRH 54 horas 53,16%. No experimento 3 os números de gestação foram: grupo CE 57,14%; grupo estro mais GnRH 48 horas 56,10% e grupo estro mais GnRH 54 horas 54,43%. Não houve diferença significativa (p > 0,05) entre os grupos. Apesar dos protocolos se mostrarem equivalentes nos resultados, o aumento do custo e da mão-de-obra dificultam sua utilização, sendo a IATF clássica mais simples e economicamente viável.

L’interconnexion croissante dans les systèmes de transports a conduit à la modélisation de nouvelles contraintes, dites contraintes de synchronisation, dans les problèmes de tournées de véhicules. Dans cette thèse, nous nous intéressons à deux cas dans lesquels ce type de problématiques apparaît. Dans un premier temps, nous proposons une méthode heuristique pour un problème à deux échelons rencontré pour la distribution de marchandises en ville. Dans un second temps, nous étudions l’intégration d’un cross-dock dans des tournées de collectes et livraisons. Une première contribution à ce sujet concerne le problème de tournées de véhicules avec cross-docking, et une seconde contribution intègre, en plus, des contraintes de ressources au cross-dock dans le problème de routage. Une méthode pour un problème de chargement 3D, étudié lors d’un stage doctoral en entreprise, est également présentée. / Transportation systems are more and more interconnected, this has lead to a new kind of constraints, called synchronization constraints, in vehicle routing problems. In this thesis, we study two cases in which this type of constraints arises. First, we propose a heuristic method for a two-echelon problem arising in City Logistics. Second, we study the integration of a cross-dockin pickup and delivery vehicle routing problems. To that end we propose a matheuristic for the vehicule routing problem with cross-docking, and we propose an extension of this problem that integrates specific resource synchonization constraints arising at the cross-dock. A method for a 3D loading problem is also presented.

Cette thèse traite de la synchronisation et de la désynchronisation des systèmes dynamiques. Dans une première partie nous abordons, sous l’angle de la biologie systémique, le problème de la désynchronisation qui consiste à induire un comportement chaotique dans un système ayant une dynamique stable. Nous étudions ce problème sur un réseau génétique appelé V-système, inventé afin de coupler le plus simplement possible une bifurcation de Hopf et une hystérèse. Après avoir démontré qu’un champ de vecteurs de R^n présentant un tel couplage peut, sous certaines conditions, avoir un comportement chaotique, nous donnons un ensemble de paramètres pour lequel le V-système associé satisfait ces conditions et vérifions numériquement que le mécanisme responsable du chaos prend place dans ce système. Dans une deuxième partie, nous nous intéressons à la synchronisation de systèmes organisés hiérarchiquement. Nous commençons par définir une structure hiérarchique pour un ensemble de 2^n systèmes par une matrice représentant les étapes d’un processus de regroupement deux par deux. Cela nous amène naturellement au cas d’un ensemble de Cantor de systèmes, pour lequel nous obtenons un résultat de synchronisation globale généralisant le cas fini. Enfin nous traitons de la situation où certains défauts apparaissent dans la hiérarchie, i.e que certains liens entre les systèmes sont brisés. Nous montrons que l’on peut accepter un nombre infini de liens brisés, tout en gardant une synchronisation locale, à condition que ces liens soient uniquement présents aux N premiers étages de la hiérarchie (pour un N fixé) et qu’ils soient suffisamment espacés dans ces étages. / This thesis deals with the synchronization and desynchronization of dynamical systems. In a first part we tackle (under a biological viewpoint) the desynchronization problem, which consists in the induce- ment of a chaotic behavior in a stable dynamical system. We study this problem on a gene regulatory network called V-system, invented in order to couple in a very simple way, a Hopf bifurcation and a hysteresis-type dynamics. After having proved that a vector field on Rn admitting such a coupling may, under some condi- tions, show a chaotic dynamics, we give a set of parameters for which the associated V-system satisfies these conditions and verify numerically that the mechanism responsible of the chaotic motion occurs in this system. In a second part, we take interest in the synchronization of hierarchically organized dynamical systems. We first define a hierarchical structure for a set of 2^n systems by a matrix representing the steps of a matching process in groups of size two. This leads us naturally to the case of a Cantor set of systems, for which we obtain a global synchronization result generalizing the finite case. Finally, we deal with the situation where some defects appear in the hierarchy, that is to say when some links between certain systems are broken. We prove we can afford an infinite number of such broken links while keeping a local synchronization, providing they are only present at the first N stages of the hierarchy (for a fixed integer N) and they are enough spaced out in these stages.

Este estudo avaliou os efeitos da administração de diferentes doses de eCG em dois momentos distintos no protocolo de sincronização da ovulação para inovulação em tempo fixo. No dia 0, as receptoras foram tratadas com dispositivo intravaginal contendo progesterona (DIP) e 2,0 mg de Benzoato de Estradiol (BE) associados a 50 mg de progesterona (P4) IM. A partir desse momento, os animais foram divididos homogeneamente para receberem 0,15 mg de d-cloprostenol (PGF2&#945;) e 400, 500 ou 600 UI de eCG no dia 5 (G-400d5, n=101; G-500d5, n=98; G-600d5, n=100, respectivamente) ou no dia 8 (G-400d8, n=100; G-500d8, n=99; G-600d8, n=96, respectivamente; fatorial 3x2). O DIP foi retirado no dia 8 e foi administrado 1 mg de BE no dia 9. No dia 17 os animais foram submetidos a ultra-sonografia ovariana e os que apresentaram mais que um corpo lúteo (CL) ou CL único maior que 18 mm de diâmetro receberam um embrião produzido in vitro. Em um grupo de animais, colheu-se amostras de sangue no dia 17 para determinação da concentração plamática de P4 (CPP4). Os animais tratados com eCG no dia 5 apresentaram maior taxa de aproveitamento [87,0 (260/299) vs. 81,7% (241/295), P<0,05], tendência de maior taxa de concepção [51,8 (132/255) vs. 45,0% (108/295), P=0,07], maior taxa de prenhez [44,1 (132/299) vs. 36,6% (108/295), P<0,05], maior número de CL (1,74 ± 0,09 vs. 1,13 ± 0,03, P<0,05) e maior proporção de receptoras com CL único de maior tamanho [CL 22: 65,7 (111/169) vs. 43,1% (94/218), P<0,05] que os tratados no dia 8. Não se observou efeito de dose sobre a taxa de aproveitamento [400: 82,1 (165/201) vs. 500: 83,8 (165/197) vs. 600: 87,2% (171/196), P<0,05], de concepção [400: 51,8 (85/164) vs. 500: 44,1 (71/161) vs. 600: 49,4% (84/170), P<0,05], de prenhez [400: 42,3 (85/201) vs. 500: 36,0 (71/197) vs. 600: 42,9% (84/196), P<0,05] e sobre a quantidade de receptoras com CL único de maior tamanho [400: 46,8 (65/139) vs. 500: 54,9 (73/133) vs. 600: 57,4 (66/115), P<0,05]. Os animais tratados com 600 UI de eCG apresentaram maior número de CL que os que receberam 400 ou 500 UI (400: 1,17 ± 0,03 vs. 500: 1,33 ± 0,06 vs. 600: 1,82 ± 0,12, P<0,05). No grupo que se determinou a CPP4 verificou-se que os animais que receberam eCG no dia 5 apresentaram maiores CPP4 que os do dia 8 (4,68 ± 0,43 vs. 2,73 ± 0,17 ng/ml, P<0,05). As novilhas tratadas com 600 UI de eCG apresentaram maiores CPP que as tratados com 400 ou 500 UI (400: 2,96 ± 0,22 vs. 500: 3,45 ± 0,38 vs. 600: 4,69 ± 0,55, P<0,05). Receptoras com mais de 1 CL apresentaram tendência de menores perdas gestacionais entre 30 e 60 dias de gestação que as com CL único [10,2 (4/49) vs. 17,5% (33/189), P=0,0547]. Os resultados são indicativos de maior eficiência do protocolo de sincronização da ovulação para transferência de embriões em tempo fixo com o uso de eCG no dia 5. A dose de eCG não influenciou na eficiência do tratamento / The aim of this study was to compare the effects of different doses of eCG administrated at two moments in a fixed-time embryo transfer protocol. On day 0, the heifers received a progesterone releasing vaginal insert (PRVI) and an injection of 2.0 mg Estradiol Benzoate (EB) associated with 50 mg progesterone (P4) i.m. The animals were randomly assigned to six treatment groups in a tree by two factorial design to receive 0.15 mg d-cloprostenol (PGF2&#945;) i.m. and 400, 500 or 600 IU eCG on day 5 (G-400d5, n=101; G-500d5, n=98; G-600d5, n=100, respectively) or on day 8 (G-400d8, n=100; G-500d8, n=99; G-600d8, n=96, respectively). On day 8, the PRVI was removed and an injection of 1 mg EB was administered on day 9. On Day 17, all heifers were examined by ultrasonography to determine the number of CL and those with more than one CL or a single CL with a diameter ?18 mm received an in vitro produced embryo. A subset of heifers were bled on day 17 for plasma P4 determination. The animals treated with eCG on day 5 presented higher proportion of heifers selected/treated [87.0 (260/299) vs. 81.7% (241/295), P<0.05], tendency to higher proportion of heifers pregnant/transferred [51.8 (132/255) vs. 45.0% (108/295), P<0.1], higher proportion of heifers pregnant/treated [44.1 (132/299) vs. 36.6% (108/295), P<0.05], higher CL number (1.74 ± 0.09 vs. 1.13 ± 0.03, P<0.05) and higher proportion of recipients with larger single CL [CL 22: 65.7 (111/169) vs. 43.1% (94/218), P<0.05] than those treated with eCG on day 8. Dose effects were not observed in the proportion of heifers selected/treated [400: 82.1 (165/201) vs. 500: 83.8 (165/197) vs. 600: 87.2% (171/196), P<0.05], pregnant/transferred [400: 51.8 (85/164) vs. 500: 44.1 (71/161) vs. 600: 49.4% (84/170), P<0.05], pregnant/treated [400: 42.3 (85/201) vs. 500: 36.0 (71/197) vs. 600: 42.9% (84/196), P<0.05] and proportion of recipients with larger single CL [400: 46.8 (65/139) vs. 500: 54.9 (73/133) vs. 600: 57.4 (66/115), P<0.05]. The animals that received 600 IU eCG presented higher CL number than those received 400 and 500 IU (400: 1.17 ± 0.03 vs. 500: 1.33 ± 0.06 vs. 600: 1.82 ± 0.12, P<0.05). In a subset of heifers that was performed a plasma P4 determination, the group that received eCG on day 5 presented higher plasmatic P4 concentration than those received eCG on day 8 (4.68 ± 0.43 vs. 2.73 ± 0.17 ng/ml, P<0.05). The use of 600 IU eCG presented higher plasmatic P4 concentration than 500 and 600 IU (400: 2.96 ± 0.22 vs. 500: 3.45 ± 0.38 vs. 600: 4.69 ± 0.55, P<0.05). Recipients with more than 1 CL tended to present lower pregnancy losses between 30 and 60 days than those with a single CL [10.2 (4/49) vs. 17.5% (33/189), P=0.0547]. The results suggest higher efficiency in the synchronization of ovulation protocol for fixed-time embryo transfer with eCG administration on day 5. The dose of eCG did not affect the efficiency of treatment

Vacas leiteira de alta produção têm apresentado declínio da eficiência reprodutiva. Essa redução é devido a causas multifatoriais, entre elas a baixa concentração de estradiol (E2) no proestro e a baixa concentração de progesterona (P4) no ciclo estral subsequentente. O objetivo deste trabalho foi comparar o uso de gonadotrofina exógena na dinâmica folicular e na taxa de prenhez de vacas submetidas ao protocolo Ovsynch (Experimento 1) ou a protocolos utilizando P4 e E2 (Experimento 2). No Experimento 1, animais de primeiro serviço foram pré-sincronizados com dois protocolos (Presynch ou Double-Ovsynch). Já os animais de segundo ou mais serviços foram resincronizados com o protocolo Resynch. Os animais receberam GnRH (1&ordm; GnRH), seguido 7 dias depois pela adiministração de prostaglandina F2&alpha; (PGF2&alpha;). Nesse momento os animais foram divididos homogeneamente por paridade e número de inseminação em um de dois tratamentos: sem FSH (Ovsynch, n = 561) ou com FSH (Ovsynch + FSH, n = 571). O segundo GnRH (2&ordm; GnRH) foi administrado 56 horas após a PGF2&alpha; e a inseminação em tempo fixo foi realizada 16 horas após. Amostras de sangue foram colhidas no 1&ordm; e no 2&ordm; GnRH, na PGF2&alpha; e 6 e 13 dias após o 2&ordm; GnRH para dosagem de P4. Ainda, no 2&ordm; GnRH dosou-se também E2 No Experimento 2, os animais foram sincronizados no dia 0 com um dispositivo de P4 associado a 2 mg de benzoato de estradiol. Oito dias após o dispositivo foi removido e os animais receberam uma dose de PGF2&alpha;. Neste mesmo momento, as vacas foram divididas homogeneamente por paridade, número de serviços prévios, escore de condição corporal e presença de CL no inicio do protocolo em três tratamentos: Controle (sem tratamento adicional; n = 232); eCG (400 UI de eCG; n = 232) e FSH (20 mg de FSH; n = 230). Todos os animais receberam GnRH e foram insemados 56h após a retirada do dispositivo. Foram colhidas amostras de sangue a cada 48h do dia 11 ao dia 22. No Experimento 1, não houve efeito do FSH na concetração sérica de E2 no 2&ordm; GnRH (P = 0,88), no tamanho do maior folículo no 2 &ordm; GnRH (P = 0,63), na taxa de ovulação ao 2&ordm; GnRH (P = 0,69) ou na concentração sérica de P4 no 6&ordm; (P = 0,15) e 13&ordm; (P = 0,36) dia após o 2&ordm; GnRH. A taxa de prenhez foi semelhante (P&gt; 0,05) entre os animais tratados com Ovsynch (36,2%) e Ovsynch + FSH (39,1%). No Experimento 2, os tratamentos não alteraram o diâmetro do folículo ovulatório (P = 0,15), o intervalo entre a remoção do dispositivo de P4 e a ovulação (P = 0,30) e a taxa de ovulação (P = 0,44). Não houve efeito de tratamento na concentração sérica de P4 (P = 0,15). A taxa de prenhez foi diferente entre os tratamentos aos 30 dias após a IATF (Controle = 28,0a vs FSH = 18,7b vs eCG = 29,7a %; P = 0,01), mas não aos 60 dias (Controle = 21,6 vs FSH = 16,1 vs eCG = 24,1%; P = 0,08) e na perda de gestacional (Controle = 18,8 vs FSH = 14,0 vs eCG = 18,4%; P = 0,39). Assim, o tratamento com FSH não estimulou o crescimento folicular final e a função luteínica de vacas leiteiras de alta produção sincronizadas com os protocolos Ovsynch e P4/E2. / Fertility in high-producing dairy cows has decreased over the years, which has been associated with reduced estradiol (E2) concentrations during proestrus and suboptimal progesterone (P4) concentrations during early stages of gestation. The objectives of the present study were to evaluate the effects of exogenous gonadotropins on follicular dynamics and risk of pregnancy per artificial insemination (P/AI) in cows subjected to the Ovsynch protocol (Experiment 1) or to a P4/E2-based timed AI protocol (experiment 2). In experiment 1, cows were enrolled in the Ovsynch protocol (GnRH, 7 d PGF2&alpha;, 56 h GnRH, 16 h IA) either after presynchronization (Presynch or Double-Ovsynch; first AI postpartum) or 32 d after previous AI. At the PGF2&alpha; injection, cows were blocked by parity and number of AI and, within each block, randomly allocated to eitherreceive 20 mg of FSH at the moment of the PGF2&alpha;(Ovsynch + FSH, n = 571) or to remain as untreated control (Ovsynch, n = 561). Blood was sampled at the 1st and 2nd GnRH and PGF2&alpha; injections, as well as on d 6 and 13 after the 2nd GnRH to access P4 and E2 (at the 2nd GnRH only) concentrations. In experiment 2, cows were received a P4 device and 2 mg of estradiol benzoate. The device was removed 8 d later concurrently with an injection of PGF2&alpha;, followed by an injection of GnRH and AI at 56 h.At the PGF2&alpha; injection, cows were blocked by parity, number of AI, body condition score, and presence of a CL at device insertion.Within each block, cows were randomly allocated to receive either 20 mg of FSH (FSH, n = 230), 400 IU of eCG (eCG, n = 232), or no additional treatment at the moment of the PGF2&alpha; (Control, n = 232). Blood was sampled at every 48 h from 1 to 12 d after AI. In experiment 1, there was no effect of FSH on serum E2 at the 2nd GnRH (P = 0.88), follicle diameter at the 2nd GnRH (P = 0.63), ovulatory response to the 2nd GnRH (P = 0.69), or serum P4 on d 6 (P = 0.15) and 13 (P = 0.36) after the 2nd GnRH. Also, P/AI was similar (P &gt; 0.05) between Ovsynch (36.2%) and Ovsynch + FSH (39.1%). In experiment 2, treatment did not affect ovulatory diameter (P = 0.15), interval from P4 device removal and ovulation (P = 0.30), ovulatory response to the 2nd GnRH (P = 0.44), and serum P4 (P = 0.15). Interestingly, treatment with FSH reduced (P = 0.01) P/AI on d 30 (Control = 28.0a vs. FSH = 18.7b vs. eCG = 29.7a %), but not on d 60after timed AI (Control = 21.6 vs. FSH = 16.1 vs. eCG = 24.1%; P = 0.08).The risk of pregnancy loss was not affected by treatment (Control = 18.8 vs. FSH = 14.0 vs. eCG = 18.4%; P = 0.39). In conclusion, treatment with FSH failed to enhance the final growth of the ovulatory follicle and did not improve luteal function after AI in high-producing dairy cows synchronized with either the Ovsynch or P4/E2-based timed AI protocols.