[pt] Evidências mostram que existe um determinado período na vida dos indivíduos onde certas preferências são desenvolvidas. Essas preferências parecem ser levadas por toda a vida, influenciando nos gostos desses indivíduos a longo prazo. Esse fenômeno vem a ser o que chamamos de Efeito Coorte. Este estudo a avalia se, conforme a teoria dos efeitos do coorte até então estudada, existe um período mais sensível da vida do indivíduo, no qual a preferência pelas tendências da moda é formada. O estudo investiga, ainda, alguns desdobramentos desta teoria, procurando identificar se existe um ponto máximo onde esta preferência ocorre. Os resultados mostraram ser compatíveis com a teoria até então estudada, fato que vem a ser de extrema relevância no trabalho de profissionais de marketing no setor da moda, além de sugerir estudos futuros mais extensivos no assunto. / [en] There is evidence that in certain period of an individual s life they develop preferences that remain unchanged throughout a lifetime. Therefore, these preferences may influence their tastes in the future. This phenomenon is called the cohort effect. This study investigates if there is a critical period in an individual s life, substantiating the cohort theory, where fashion preferences are developed. Other implications of this theory is explored in this study by trying to identify if there is a specific period, where these preferences occur. The results seem to be consistent with the existing cohort theory, which is extremely relevant for marketing professionals in the fashion business, and highlights the need for future studies for further investigation.

Lentil is an important pulse crop in Saskatchewan. Weed control is central to lentil production due its poor competitive ability and the few herbicide options for use on conventional varieties. Imidazolinone tolerant lentil varieties have been developed to improve herbicidal weed control and crop safety. Two studies were conducted in 2006 and 2007 in Saskatchewan with the research objective of determining the optimal weed control timing and herbicide to maximize weed control and lentil yield. The first experiment investigated the critical period of weed control (CPWC) for lentil. The CPWC was realized by investigating two components; the duration of weed interference and the duration of the weed-free period which respectively determine the beginning and end of the CPWC. The crop remained weedy or weed-free from zero to eleven lentil nodes to investigate the durations of weed interference and weed-free period. There was an inverse relationship between weed biomass and lentil yield such that lentil yield was highest when weed biomass was minimal. The CPWC was found to commence at the five node stage and continue to the ten node stage. The second experiment investigated imazethapyr / imazamox, imazamox and metribuzin + sethoxydim applied at two application times to determine the best herbicide for the CPWC. The results indicated that imazethapyr / imazamox and imazamox applied at the six node stage resulted in the overall lowest weed biomass and highest lentil yield compared to application at the two node stage. In accordance with these results and the CPWC, imazethapyr / imazamox or imazamox should be applied at or before the five to six node stage to maximize lentil yield and minimize weed biomass.

Environmental experiences play a critical role in an individualʼs risk of becoming addicted. Positive experiences may mitigate addiction vulnerability, whereas adverse experiences, particularly during adolescence, have been shown to increase addiction risk. Social isolation in rodents is a model system used to study the effects of such experiences, yet its impact on the learning and memory processes that underlie addiction remains elusive. Although social isolation is known to alter the functioning of the dopaminergic system, as well as reward processing and learning, its effect on dopamine (DA) neurons of the ventral tegmental area (VTA) is unknown. The data presented in this dissertation demonstrate that social isolation of rats during a critical period in adolescence (postnatal days 21-42) enhances long-term potentiation (LTP) of N-methyl D-aspartate receptor (NMDAR)-mediated glutamatergic transmission in the VTA. Activation of NMDARs is critical to the generation of DA neuron bursts that encode rewards and reward-predictive cues, and NMDARs are necessary for associative reward learning. The isolation-induced enhancement of NMDAR LTP results from augmentation of metabotropic glutamate receptor (mGluR)-dependent calcium (Ca²⁺) signaling via an increase in inositol 1,4,5-trisphosphate(IP3) sensitivity. Isolation-mediated effects on Ca²⁺ signaling and NMDAR plasticity were not reversed by a subsequent period of resocialization. Furthermore, social isolation during this critical period occludes the effect of repeated amphetamine exposure on mGluR/IP₃-mediated Ca²⁺ signaling and synaptic plasticity. Although corticotropin releasing factor (CRF) further facilitates mGluR/IP3-mediated Ca²⁺ signaling in DA neurons, alterations in CRF receptors are not responsible for the effects of isolation on Ca²⁺ signaling and synaptic plasticity. In addition, the learning of associations between environmental stimuli and drug rewards is acquired more quickly and is more resistant to extinction in isolated animals. Data presented in this dissertation lend support to the theory that enhanced mGluR/IP₃-mediated Ca²⁺ signaling and NMDAR plasticity facilitate the learning and memory of drug-associated stimuli. This dissertation provides the first demonstration of a cellular basis for the critical time window of social isolation during adolescence. NMDAR plasticity in the VTA may thus represent a neural substrate by which early life experiences regulate addiction vulnerability. (Note: Behavioral data were acquired by Mickael Degoulet) / text

Development of brain function is instructed by both genetically-determined processes (nature) and environmental stimuli (nurture). The relative importance of nature and nurture is a major question in developmental neurobiology. In this dissertation, I investigated the role of visual experience in the development and plasticity of the visual pathway. Each neuron that receives visual input responds to a specific area of the visual field- their receptive field (RF). Developmental refinement reduces RF size and underlies visual acuity, which is important for survival. By rearing Syrian hamsters (Mesocricetus auratus) in constant darkness (dark rearing, DR) from birth, I investigated the role of visual experience in RF refinement and plasticity. Previous work in this lab has shown that developmental refinement of RFs occurs in the absence of visual experience in the superior colliculus (SC), but that RFs unrefine and thus enlarge in adulthood during chronic DR. Using an in vivo electrophysiological approach, I show that, contrary to a widely held view, visual experience is not necessary for refinement of RFs in primary visual cortex (V1). In both SC and V1, RFs refine by postnatal day (P) 60, but enlarge by P90 with chronic DR. One week of visual experience was sufficient to prevent RF enlargement in SC and V1. How normal sensory experience prevents plasticity in mature circuits is not well understood. Using an in vitro electrophysiological approach, I demonstrated that GABAergic inhibition is reduced in DR SC, which in turn affects short-term (but not long-term) synaptic plasticity. The level of GABABR-mediated short-term synaptic depression (STD) that occurs during high-frequency afferent stimulation, such as occurs during vision, is reduced by DR. Using a computational model of RF size, I propose that, in addition to the effect of reduced inhibition, reduced STD of excitation could contribute to enlarged RFs. This work provides insight into mechanisms of development and plasticity of the nervous system. How plasticity is restricted in mature circuits is of fundamental importance in neuroscience and could instruct therapies to prevent maladaptive plasticity in disease and to enhance recovery of function in adults.

Orientador: Pedro Luís da Costa Aguiar Alves / Banca: Dagoberto Martins / Banca: Roberto Estêvão Bragion de Toledo / Banca: Maria Aparecida Pessoa da Cruz Centurion / Banca: Silvano Bianco / Resumo: Este trabalho teve como objetivo identificar os períodos de interferência das plantas daninhas no algodoeiro de fibra naturalmente colorida (BRS Safira e BRS Verde), e avaliar o efeito da competição das plantas daninhas na produtividade desta cultura. Dois experimentos foram instalados na área experimental da Embrapa Algodão em Missão Velha, CE, (7º42'07'' de latitude e 39º24'18'' de longitude, altitude de 360 m) na safra 2007/2008, utilizando-se o espaçamento de 1,00 x 0,20 m. Utilizou-se o delineamento experimental em blocos ao acaso, com quatro repetições, os tratamentos constaram de duas: modalidades de competição (convivência e controle de plantas daninhas) e períodos de interferência das plantas daninhas. Os períodos iniciais de controle ou de convivência após a emergência da cultura foram 0-20, 0-40, 0-60, 0-80 dias após a emergência (DAE) e 0-colheita (120 dias). Para determinação dos períodos de interferência, considerando-se perdas na produtividade de 2, 5 e 10%; foi realizada análise de regressão do modelo sigmoidal de Boltzmann, utilizando-se os dados de produtividade separadamente dentro de cada modalidade de competição. A comunidade infestante para ambas cultivares, foi composta por 21 espécies, destacando-se: Richardia grandiflora, Amaranthus deflexus, Eleusine indica, Merremia aegyptia, Eragrotis pilosa, Cenchrus echinatus e Waltheria indica. Observou-se para cultivar BRS Safira, que os períodos anteriores a interferência (PAI) foram, respectivamente, 8, 14 e 20 DAE, para perdas na produtividade de 2, 5 e 10%; e os períodos críticos de prevenção a interferências (PCPI), para esses mesmo níveis de perdas, foram respectivamente, 100, 82 e 60 dias. Para cultivar BRS Verde, os PAIs foram, respectivamente, 25, 31 e 35 DAE, para perdas de 2, 5 e 10%; e os PCPIs, para esses mesmo níveis de perdas, foram respectivamente ...(Resumo completo, clicar acesso eletrônico abaixo) / Abstract: This study aimed to determine the late-season presence of weeds in reddish brown cotton and green cotton (cultivars BRS Safira and BRS Verde) and the critical times for removing weeds. And assess the effect of weeds competition in the crop productivity. Two experiments were carried out in the area of Embrapa in Missão Mission-CE, Brazil, the region Cariri, located at 7º42'07'' S latitude and 39º24'18'' WGr. longitude, altitude of 360 m, in the 2007/2008 season. The treatments consisted of two control groups: weed-free crop during the initial period after crop emergency, and crop kept with weeds during initial period after plant emergency. Both consisted, 0, 20, 40, 60, 80 e 120 days after crop emergency (DAE). Regression analysis was performed of the model of sigmoidal Boltzmann, using data from productivity separately within each type of competition, to identify the critical periods of competition considering 2, 5 and 10% reduction in yield. The community of weeds, for both cultivars, was composed by 21 predominant species, standing out among them: Richardia grandiflora, Amaranthus deflexus, Eleusine indica, Merremia aegyptia, Eragrotis pilosa, Cenchrus echinatus and Waltheria indica. For cultivar BRS Safira, considering 2, 5 and 10% reduction in yield fiber as acceptable, the period preceding the interference was, respectively, 8, 14 and 20 (DAE). And the critical periods of prevention to interferences, for those same levels of losses, they were respectively, 100, 82 and 60 (DAE). For cultivar BRS Verde, considering 2, 5 and 10% reduction in yield fiber as acceptable, the period preceding the interference was, respectively, 25, 31 and 35 (DAE). And the critical periods of prevention to interferences, for those same levels of losses, they were respectively, 67, 43 and 22 (DAE). The BRS Safira cultivar was more susceptible to interference of the weed community that BRS Verde. / Doutor

Previous research done in sociophonetic variation of second language speakers has often looked at constraints of formality affecting degree of foreign accent and how this degree of formality can have effects on what speaking styles speakers choose to employ. Furthermore, other social constraints of convergence and divergence of speech affect speaker speaking style. However, no known previous research has examined interdental fricative /θ ð/ substitution based on each speaker's interlocutor. This study explores second language speakers' English interdental fricative substitution sounds in terms of sociophonetic variation of formality and speaker interlocutor(s). Five native language pairs of Arabic, Cantonese, French, Portuguese, and Vietnamese origin were part of the study, comprising ten participants in total. The study finds age of English onset, as verified by the literature, to be the most determining factor for accurate articulation of these marked fricatives. However, other constraints for substitution choice are at hand including phonological limitations and estimated linguistic experience based on demographic information given by survey participants. The primary aim of the study is to associate some of the interdental fricative substitutions with a social variable. Data for the study include recordings of each participant reading a poem by him/herself, a dialogue with the other same native language participant, and a dialogue with a native speaker of American English. The data analysis examined the replacement sounds in terms of native language background, linguistic experience variables, and phonological constraints. In addition, quantities and ratios of specific replacement sounds for each participant per recording and per native language pair were compared and contrasted to find if speech accommodation theory (SAT), as proposed by Giles et al. (1991), played a role in any of the participants' choices for substitution. The study finds both convergence and divergence of interdental fricative substitutions to be characteristic of speakers with less linguistic experience in English. An additional stronger finding is that most participants' most common sound substitutions for the voiced and voiceless interdental fricatives were independent in place and manner, the voiced most commonly replaced by dental and alveolar plosives [ḏ d] and the voiceless most commonly replaced by labiodental fricative [f], which could be an indication of each fricative's acoustic and phonemic representation in each non-native speaker's phonological component, supported by findings of Brannen (2002). Some literature suggests that varying values of [continuant] in speakers' native languages are the means by which speakers choose the replacement sounds they do. However, such an explanation cannot be the only valid one when inherent variability comes into play and different places and manners of articulation are chosen for both interdental fricatives.

Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2016-07-28T14:16:35Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação_Laís Alves Ribeiro Costa_Março 2016.pdf: 1135215 bytes, checksum: 869ddf6af6f8a4e05c7e9a6d6831f190 (MD5) / Made available in DSpace on 2016-07-28T14:16:35Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação_Laís Alves Ribeiro Costa_Março 2016.pdf: 1135215 bytes, checksum: 869ddf6af6f8a4e05c7e9a6d6831f190 (MD5) Previous issue date: 2016-03-02 / CAPEs / O excesso de peso representa um dos grandes problemas da sociedade. A alimentação saudável, incluindo o consumo dos ácidos graxos insaturados, exerce fator crucial na prevenção e tratamento das doenças ocasionadas pela obesidade, incluindo aquelas que acometem o sistema nervoso central. O objetivo deste estudo foi investigar, em ratos jovens, efeitos da ingestão alimentar excessiva associada a suplementação com óleo de cártamo sobre parâmetros metabólicos, comportamentais e eletrofisiológicos. Ratos Wistar foram divididos em grupos referentes ao estado nutricional, com ninhadas contendo 03 ou 09 animais, e subdivididos quanto à suplementação com óleo de cártamo ou veículo no período do 7º ao 30º dia de vida por via oral. Após o período de suplementação, dados da murinometria, comportamento referente à ansiedade e memória episódica e registro eletrofisiológico foram coletados. Os resultados indicam que ratos criados em ninhadas com tamanho reduzido apresentaram aumento peso corporal, circunferência abdominal e torácica, comprimento corporal, índice de massa corporal e peso do fígado, quando os dados foram comparados com os respectivos controles. Os ratos submetidos à ingestão alimentar excessiva apresentaram maior ansiedade e redução da velocidade da depressão alastrante cortical (DAC). Por outro lado, o óleo de cártamo, independente do estado nutricional, apresentou maior velocidade de propagação da DAC. Além disso, todos os animais deste estudo foram bem sucedidos na tarefa de reconhecimento de objetos, com preferência em explorar o novo objeto. Os resultados sugerem que o estado nutricional na fase inicial da vida pode acarretar em prejuízos metabólicos, comportamentais e na excitabilidade cortical. Em contrapartida, o óleo de cártamo parece reverter o efeito do excesso alimentar sobre sistema nervoso. / Overweight represent one of the major problems of society. Healthy eating, including consumption of unsaturated fatty acids, exerts a crucial factor in the prevention and treatment of diseases caused by obesity, including those that affect the central nervous system. The objective of this study was to investigate in young rats, effects of excessive food intake associated with safflower oil supplementation on metabolic, behavioral and electrophysiological parameters. Wistar rats were divided in groups with related to nutritional states, with litters containing 03 or 09 pups, and subdivided either as orally supplemented with safflower oil or vehicle in the period from 7th to 30th day of life. After this supplementation period, murinometric data, anxiety-like behavior, episodic memory, and electrophysiological recordings were collected. The results indicate that rats raised in reduces litter size presented increased body weight, thoracic and abdominal circumference, body length, body mass index and liver weight when the data was compared with the respective controls. Rats subjected to excessive food intake showed enhanced anxiety-like behavior and reduced velocity of the cortical spreading depression (CSD). Moreover, animals supplemented with safflower oil, regardless of nutritional state, showed higher speed of propagation of CSD. Furthermore, all animals in this study were successful in the object recognition task, with preference in exploring the new object. The results suggest that the nutritional state in early life can lead to metabolic, behavioral and cortical excitability impairment. On the other hand, safflower oil can appears to reverse the effect of the excess food nervous system.

Repair of peripheral nerve injury often results in poor functional motor recovery. This deficit has previously been attributed to the failure of axons to regenerate into the muscle. However, we have recently reported that following nerve injury in mice, axons have regenerated to the motor end plate in animals with poor recovery. We proposed that following axonal injury, there is a critical period during which the axon must reach the muscle in order to form a functional neuromuscular junction. We have developed a mouse model of prolonged denervation, in which the sciatic nerve is crushed repeatedly every few days, preventing regenerating axons from reaching the muscle. This multiple crush model allows us to vary the period of denervation by modifying the number of crushes. Motor recovery as assessed using the toe-spreading score occurs after 3 or 4 multiple crushes every 7 days (24 or 31 days of denervation) but not after 5 crushes (38 days). Immunostaining for alpha-bungarotoxin and neurofilament confirmed end plate reinnervation. Thus following denervation > 38 days, a motor deficit persists despite end plate reinnervation. Although the mechanism for the deficit requires investigation, these results suggest that functional neuromuscular junction reestablishment more than end plate reinnervation and that there is a time limit for functional synapse reformation.

Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2017-07-13T13:30:25Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Dissertação_JanatarStellaVaconcelosdeMelo_2016.pdf: 1719619 bytes, checksum: 6315f0db6eb0f7ba21328cc670638617 (MD5) / Made available in DSpace on 2017-07-13T13:30:25Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Dissertação_JanatarStellaVaconcelosdeMelo_2016.pdf: 1719619 bytes, checksum: 6315f0db6eb0f7ba21328cc670638617 (MD5) Previous issue date: 2016-03-03 / CAPES / As fases iniciais da vida representam um período crítico no desenvolvimento do sistema nervoso. O objetivo desse estudo foi avaliar efeitos da associação entre exercício físico em esteira e suplementação com óleo de peixe em ratosno início da vida, sobre ansiedade, memória e excitabilidade cerebral. Ratos Wistar foram divididos em: Óleo de Peixe ou Veículo e subdivididos em Exercitados ou Sedentários. O período de treinamento ocorreu do 15º ao 45º dias de vida. A partir dos 46 dias de vida, foi realizada avaliação dos efeitos dessa associação sobre peso corporal, murinometria, respostas comportamentais relacionadas à ansiedade, memória e eletrofisiologia cortical. Os resultados demonstram que não houve alteração nos dados murinométricos. No teste de labirinto em cruz elevado, os animais exercitados apresentaram comportamento menos ansioso a julgar pelo maior número de entradas nos braços abertos. Além disso, animais suplementados e/ou exercitados apresentaram memória preservada para reconhecimento da identidade do objeto. Por outro lado, a análise intragrupo demonstrou prejuízo dependente do tratamento, quando os animais foram submetidos ao teste de reconhecimento quanto à localização do objeto. Com relação à análise intergrupo, a suplementação e o exercício aumentaram o índice de discriminação para o objeto estacionário. Sobre a eletrofisiologia cerebral, houve potencialização da suplementação sobre o exercício na redução da velocidade de propagação da depressão alastrante cortical. Neste contexto, os resultados indicam que é necessária cautela no uso da associação dessas estratégias referentes à modulação comportamental ou neural em períodos críticos de desenvolvimento do sistema nervoso. / The early stages of life represent a critical period in the development of the nervous system. The aim of this study was to evaluate how the association between treadmill exercise and supplementation with fish oil in rats during lactation affect anxiety, memory and brain excitability. Wistar rats performed two experimental groups as Fish Oil or vehicle, and then divided into exercised or sedentary. The training period was from the 15th to 45th days of life. From the 46 days of life, the effects of this combination on body weight, murimetric parameters, behavioral assessment, and cortical electrophysiology were evaluated. The results demonstrate that there was no change in murinometric data. In the elevated plus maze, exercised animals were less anxious as judged by the largest number of entries into the open arms as compared to the respective controls. Furthermore, supplemented and / or trained animals showed preserved memory to recognize the identity of the object. On the other hand, the intra-group analysis showed treatment-dependent impairment when the animals were subjected to the recognition test on the object location. The inter-group analysis supplementation and exercise increased the discrimination index for the stationary object. In addition, supplementation with fish oil enhanced the effect of exercise on brain excitability by reducing the velocity of propagation of cortical spreading depression. Therefore, the present data indicate that caution is required in use of the association of these strategies concerning behavioral or neural modulation.

京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第22163号 / 農博第2377号 / 新制||農||1074(附属図書館) / 学位論文||R2||N5243(農学部図書室) / 京都大学大学院農学研究科地域環境科学専攻 / (主査)教授 舟川 晋也, 教授 縄田 栄治, 准教授 真常 仁志 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DFAM