33 research outputs found
Response of zooplankton to nutrient enrichment and fish in shallow lakes: a pan-European mesocosm experiment
Microbial associations in sponges. III. Ultrastructure of the in situ associations in coral reef sponges
Novas funções para estimar a produção de leite, em 305 dias de lactação, de vacas da raça Gir New functions to estimate 305-days milk production of Gir cows
Os objetivos neste estudo foram, a partir da forma generalizada da função de Michaelis-Menten, derivar novas funções, acumulada e diária, para estimar a produção de leite, em 305 dias de lactação, de vacas da raça Gir, usando informações de produção de leite no dia do controle leiteiro. Foram utilizadas 7.412 lactações de 3.416 vacas da raça Gir com partos entre 1987 e 2004, distribuídos em 51 rebanhos participantes do Programa Nacional de Melhoramento Genético do Gir Leiteiro, coordenado pela Embrapa Gado de Leite e pela Associação Brasileira dos Criadores de Gir Leiteiro. Foram ajustados os modelos para as subclasses nível de produção (Alto > 2.628 kg de leite na lactação; Baixo <2.628 kg de leite na lactação), estação de parição (Seca e Águas) e ordem de parição (OP 1 a 5 e >5). Os valores do desvio-padrão residual variaram de 0,131 a 0,984, os do Coeficiente de Determinação (R²) foram próximos de 1 e de Durbin-Watsom foram próximos de 2. A estatística de Theil (U) apresentou valores de U M e U V próximos de 0 e de U C próximos de 1, sugerindo acurácia das estimativas. Estes resultados indicam bom ajuste da função. A persistência da lactação relaciona-se ao parâmetro d e o tempo de ocorrência do pico da lactação se relaciona simultaneamente com os parâmetros d e n. Então, as novas funções ajustam-se bem a lactações de vacas da raça Gir e são caracterizadas pela simplicidade no procedimento de ajuste, pela facilidade de interpretação biológica dos parâmetros e pela flexibilidade, ou seja, é possível obter a função acumulada a partir da função diária. As novas funções apresentam-se como funções alternativas para projetar lactações não encerradas e podem ser utilizadas na avaliação genética de animais em programas de melhoramento genético.<br>This study aimed to calculate new accumulated and daily functions based on the Michaelis-Menten equation to estimate the 305-days production of Gir cows using test day milk yields. Data consisted of 7,412 lactation records of 3,416 Gir cows (Bos indicus) collected from 1987 to 2004 in 51 herds assisted by the National Breeding Program of the Dairy Gir, coordinated by the Dairy Cattle National Research Center (EMBRAPA) and the Brazilian Association of Dairy Gir Breeders (ABCGIL). The models included the effects of herd milk production (High and Low), calving season (dry e rainy) and parity order (OP 1 to 5 and > 5). Residual Standard Deviation values ranged from 0.131 to 0.z984. Estimates for the Coefficient of Determination (R²) were close to one and for the Durbin-Watson coefficient were close to two. Values of statistics of Theil (U) were close to zero for U M and U V and close to one for U C suggesting a good fitting for the function. The persistency of milk yield is related to the parameter d and the time of the pick yield is related to both parameters d and n. The new functions are characterized by simplicity of the fitting procedure, biological interpretability of the parameters and flexibility to convert the daily function to the accumulated function. The new functions are an alternative to project lactations with records in progress to estimate the production required in genetic evaluation systems based on 305-day milk production records
Defensive reactions to health-promoting information: an overview and implications for future research
It is a common finding that recipients of threatening health-promoting information are motivated to dismiss or disregard the information, thus reacting defensively'. This article gives an overview of the literature on defensive reactions to health-promoting information. A distinction is made between: (1) avoidance, (2) denial, (3) cognitive reappraisal and (4) suppression. Although these defensive reactions have been studied repeatedly and thoroughly, we propose that a number of questions remain unanswered. First, little is known about whether avoidance, denial, cognitive reappraisal and suppression have distinct or similar effects on emotional experience and health-conducive behaviour. Second, little is known about the development of defensive reactions over time in case recipients are repeatedly exposed to health-promoting information, which is often the case in a real-life setting. In the present article, we present preliminary answers to these questions, suggesting that cognitive reappraisal has greater potential to result in effective emotion regulation and is more likely to impede healthy behaviour than the other three strategies. We also propose that defensive reactions to health-promoting information do not always reduce health-conducive responses but can co-occur with more adaptive responses or even facilitate them. Finally, we present a hypothesised model of the development of defensiveness over time