DSpace Collection:
http://hdl.handle.net/10174/656
2024-03-28T14:48:41ZMECANISMOS HOMEOSTÁTICOS E HOMEORRÉTICOS DECORRENTES DA ACLIMATIZAÇÃO SAZONAL EM BOVINOS LEITEIROS DE DIFERENTE CAPACIDADE PRODUTIVA
http://hdl.handle.net/10174/34630
Title: MECANISMOS HOMEOSTÁTICOS E HOMEORRÉTICOS DECORRENTES DA ACLIMATIZAÇÃO SAZONAL EM BOVINOS LEITEIROS DE DIFERENTE CAPACIDADE PRODUTIVA
Authors: Gomes da Silva, Flávio; Cachucho, Liliana; Matos, Catarina; Geraldo, Ana; Conceição, Cristina; Lamy, Elsa; Capela e Silva, Fernando; Infante, Paulo; Pereira, Alfredo
Editors: Pereira, Alécio M.; Costa de Sousa, Gilcyvan; Viana, Gregório E.N.
Abstract: O objetivo deste estudo consistiu em avaliar a resposta fisiológica de bovinos leiteiros, de raça Holstein-Frísia, com diferente potencial para a produção de leite, em duas fases de aclimatação sazonal. Utilizando a produção de leite corrigida para os 305 dias de lactação, foram selecionadas 6 vacas multíparas, com uma produção de leite inferior a 9000 kg (BP) e 7 vacas multíparas, com produção de leite superior a 9000 kg (AP). Os animais foram acompanhados em dois períodos durante 5 dias (P1: animais aclimatados às condições de Verão submetidos a temperaturas que indiciam stress térmico; P2: animais aclimatados às condições de inverno submetidos a temperaturas dentro da faixa de termoneutralidade). Mediu-se a temperatura de globo negro (TGN), à sombra e ao sol, a frequência respiratória (FR), a taxa de sudação (TS) e a temperatura retal (TR) em ambos os períodos. Diariamente registou-se as produções de leite de cada vaca e recolheu-se amostras de leite para a determinação da sua composição química e células somáticas. Em cada período foi recolhida uma amostra de sangue para a determinação de parâmetros bioquímicos e da triiodotironina (T3). Observou-se a influência do fator período na TGN, FR, TS, TR, na composição leiteira, nos parâmetros hematológicos e no metabolismo (T3). Foram observados valores superiores de ureia do leite e valores inferiores de T3 nas AP durante o P1. Estes resultados mostraram que vacas com diferente potencial leiteiro apresentaram uma resposta ao calor semelhante, no entanto, com a aclimatação as AP demonstraram modificações fisiológicas mais pronunciadas, com uma redução da taxa metabólica e com alterações no metabolismo do azoto.2023-01-01T00:00:00ZStructuring Genotype X Environment Interaction by Regression Techniques
http://hdl.handle.net/10174/30320
Title: Structuring Genotype X Environment Interaction by Regression Techniques
Authors: Pereira, D. G.; Rodrigues, P. C.; Mejza, Stanislaw; Mexia, J. T.
Editors: Iriti, Marcello
Abstract: The investigation of the structure of genotype-by-environment interaction is an important topic in multi-environment trials, in which a series of tests are undertaken across multiple environmental conditions. This study proposes a generalisation of joint regression analysis for situations when the response (e.g. yield) is non-linear across environments and can be expressed as a second (or higher) order polynomial or another non-linear function. We propose a selection technique based on the modification of two tests after determining the common form regression function for all genotypes: (i) a test for parallelism of regression curves; and (ii) a test of coincidence for those regressions. When the parallelism hypothesis is ruled out, subgroups of genotypes with parallel (or coincident) responses should be found. The Scheffé multiple comparison approach for regression coefficients in second-order polynomials allows for the classification of genotypes into two categories: one with upward-facing concavity (i.e. potential yield growth), and the other with downward-facing concavity (i.e. the yield approaches saturation). With an example of yield from a non-orthogonal series of experiments with winter rye, theoretical conclusions for genotype comparison and genotype selection are demonstrated (Secale cereale L.). To demonstrate that our meteorology is entirely relevant to incomplete data sets, we randomly erased 10% of that data, which are common in multi-environment trials. The hypothesis of parallelism of regression curves was rejected, which is natural in multi-environment trials with interaction between genotype and environment. The main difference in the two subgroups of genotypes where the responses are parallel is that one group had upward-facing concavity (i.e. potential yield growth) and the other had downward-facing concavity (i.e. the yield approaches saturation), which can help breeders in their genotype selection. The approach proposed in this paper is general and applicable to any series of experiments conducted in multi-environment trials or simply to the case of two-way classified data.2021-06-30T23:00:00ZResilient Software Architecture Platform for the Individual Care Plan
http://hdl.handle.net/10174/29863
Title: Resilient Software Architecture Platform for the Individual Care Plan
Authors: Mendes, David; Lopes, Manuel José; García-Alonso, José Manuel; Santos, Jorge M Azevedo; Sousa, Luís Manuel Mota
Abstract: The individual care plan (ICP) is a metamorphic being. The only steady reality that it maintains is its final objective, stated and explained in the previous chapter where the ICP is thoroughly introduced and debated. It is a fantastic beast, better described as a system of systems that is severely polymorphic due to its coverage both in level of care as well as sources of data to handle. Patient monitoring generates large volumes of data. There is the evident need of an advanced approach that can deal with these huge amounts of healthcare data extracted from various sources such as the wearable sensors, medical, and nursing records that are currently called big data. The purpose of this chapter is to introduce and discuss the software platform that is adequate to develop and deploy the system paying attention to the needs of high-availability, sensitive information security; service-level agreements for multiple healthcare interoperability; law and ruling conformance; as well as other technical and ethical aspects.2020-01-01T00:00:00ZHarvesting Policies with Stepwise Effort and Logistic Growth in a Random Environment
http://hdl.handle.net/10174/28527
Title: Harvesting Policies with Stepwise Effort and Logistic Growth in a Random Environment
Authors: Brites, Nuno; Braumann, Carlos
Abstract: Recently, we have developed optimal harvesting policies based on profit
optimization in random varying environments. Namely, we have considered a
logistic stochastic differential equation growth model, with the purpose of discussing
the use of variable versus constant effort harvesting policies in terms of
the expected accumulated discounted profit during a finite time interval. Using
realistic parameters, we have concluded that there is only a slight reduction in
profit when choosing the applicable constant effort policy instead of the variable
effort policy, which presents strong disadvantages. Here, we apply a logistic growth
model and a more general profit structure to present alternative policies based on
variable effort, named stepwise policies, where the harvesting effort is determined,
under the optimal variable effort policy, at the beginning of each year (or of each
biennium) but is kept constant during that year (biennium). Replacing the optimal
variable effort policy by these stepwise non-optimal policies has the advantage of
applicability but, at best, considerably reduces the already small profit advantage the
optimal variable effort policy has over the optimal constant effort sustainable policy.2020-01-01T00:00:00Z