Testing physiologically-based resource allocation rules in laboratory experiments with Daphnia magna Straus

The rules governing the allocation of available resources to varying physiological processes are evaluated in three physiologically-based models of individual Daphnia. In laboratory experiments using a single clone, subjected to varying regimes of food deprivation, growth was found to vary inversely with food level, ceasing in the absence of food, implying that growth allocation is derived directly from food. Reproductive investment was reduced under food deprivation, ceasing at low food levels. By exposing juvenile and adult daphnia to varying food deprivation regimens during different periods within their intermoult interval, it was shown that instar durations vary as a function of body size and food availability independent of the age of the animal. For the first time, the role of variable instar duration, which critically influences physiological processes such as growth, moulting and reproduction in adult females, that has been neglected by existing Daphnia models, is explicitly incorporated in a physiological allocation model. The consequent model provides a simplified framework for modelling the consequences of food deprivation in cladocerans which has important application in population modelling and environmental risk assessment.EC - STEP and Environment ProgrammesEV5V-CT91-0009EV5V-CT94-0422FCTPRAXIS programBritish Counci

Inseminação Artificial em Tempo Fixo (IATF).

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An approach to comfort in 3D printed clothing

A prototipagem rápida (3D) tem se apresentado como uma promissora técnica de produção. Diante do fato, diversas questões surgem com relação a mudança nos processos de produção, nomeadamente a percepção do conforto nos produtos obtidos por esta tecnologia. O presente artigo faz uma revisão acerca do conforto, das técnicas de impressão 3D e apresenta uma breve reflexão entre o conforto e os produtos vestíveis.The rapid prototyping (3D) has become a promise of production techniques. Faced with the fact, several questions arise regarding the change in the production process, namely the perception of comfort in the products obtained by this technology. This paper reviews the background of 3D printing techniques and presents a brief reflection between comfort and wearable products.info:eu-repo/semantics/publishedVersio

Measurement errors in body size of sea scallops (Placopecten magellanicus) and their effect on stock assessment models

Body-size measurement errors are usually ignored in stock assessments, but may be important when body-size data (e.g., from visual sur veys) are imprecise. We used experiments and models to quantify measurement errors and their effects on assessment models for sea scallops (Placopecten magellanicus). Errors in size data obscured modes from strong year classes and increased frequency and size of the largest and smallest sizes, potentially biasing growth, mortality, and biomass estimates. Modeling techniques for errors in age data proved useful for errors in size data. In terms of a goodness of model fit to the assessment data, it was more important to accommodate variance than bias. Models that accommodated size errors fitted size data substantially better. We recommend experimental quantification of errors along with a modeling approach that accommodates measurement errors because a direct algebraic approach was not robust and because error parameters were diff icult to estimate in our assessment model. The importance of measurement errors depends on many factors and should be evaluated on a case by case basis