Capturing the life history of the marine copepod Calanus sinicus into a generic bioenergetics framework.`

Quantitative knowledge about copepod life histories is of crucial importance to interpret and predict the impacts of natural and anthropogenic stressors in this taxonomic group. Dynamic Energy Budget (DEB) models are a useful tool in this context, as they quantitatively link the energy taken up by feeding to energy-demanding traits such as growth, development and reproduction. The copepod life cycle, however, has several features that require closer investigation. Firstly, they sport larval development through six naupliar stages (of which the initial stages do not feed), followed by six copepodite stages (which have a different shape from the nauplii). Furthermore, growth stops rather abruptly after the final moult to the adult stage, and many species build up a large lipid storage to survive, and initiate reproduction, in absence of food. After a few modifications, the simple and generic DEBkiss model could be calibrated for Calanus sinicus using data on body composition and size at age for different temperatures. Embryo and naupliar development were well explained by the model, after correcting for their deviating shape from the copepodites. Ceasing of growth after the final moult was implemented as a size-dependent switch in allocation. With these assumptions, predictions could be made for the rates of ingestion, respiration and reproduction in adults. The predictions were consistent with observed rates, which indicates the realism of the model structure and its parameterisation. Several issues remain to be addressed, specifically, the dynamics of lipid storage and its use. However, the present study provides a starting point for applications of DEB theory to copepods

Modelling aboveground net primary production (ANPP) of an Atlantic mountain grassland based on time series approach

Because primary productivity is related both with the energy that sustains food webs and with species diversity, it is usually considered a key ecosystem property and a reliable indicator of available forage. In this work the aboveground net primary production (ANPP) of an Atlantic mountain grassland system was modelled in order to attempt producing short-term forecasts. Since grazing influences productivity, two treatment levels (grazing and exclusion) were experimentally applied in each of three field sites. Monthly ANPP data were then collected over three consecutive vegetative periods (2006-2008), thereby obtaining six time series (one per plot). Since no significant differences among sites (within treatments) were found, these six series were later reduced through averaging to only two series (one per treatment level). Two kinds of statistical models were then used to attempt monthly ANPP forecasting: exponential smoothing methods and ARIMA models. Both methodologies turned out to produce inadequate forecasts due to the presence of marked local features (innovative outliers) in our relatively short time-series data. Nonetheless, useful information for a more innovative shepherding management was revealed (e.g. the presence of within-year variation in ANPP, and differences between the grazing and exclusion treatments). Longer data series, which would require a more demanding effort in sampling investment, are likely necessary in order to obtain adequate forecasts using these time series methodologies.Debido a que la producción primaria está relacionada tanto con la energía que sustenta las redes tróficas como con la diversidad de especies, generalmente se considera una propiedad clave del ecosistema y un indicador fiable del forraje disponible. En este trabajo se modeló la producción primaria neta aérea (ANPP) de un sistema de pastizales atlánticos de montaña con el fin de intentar pronosticarla a corto plazo. Como el pastoreo influye en la productividad, se aplicaron experimentalmente dos niveles de tratamiento (pastoreo y exclusión) en cada uno de los tres sitios de estudio. Los datos mensuales de ANPP se recolectaron a lo largo de tres períodos vegetativos consecutivos (2006-2008), obteniendo así seis series temporales (una por parcela). Dado que no se encontraron diferencias significativas entre los sitios (dentro de los tratamientos), estas seis series fueron promediadas y reducidas a dos (una por nivel de tratamiento). Posteriormente, se utilizaron dos tipos de modelos estadísticos para pronosticar la ANPP mensual: métodos de suavizado exponencial y modelos ARIMA. Ambas metodologías arrojaron pronósticos inadecuados debido a la presencia de características locales marcadas (valores atípicos innovadores) en nuestros datos de series temporales relativamente cortas. No obstante, se reveló información útil para un diseño de manejo del pastoreo más adecuado (por ejemplo, la presencia de variación dentro de un año en la ANPP y diferencias entre los tratamientos de pastoreo y exclusión). Es probable que se necesiten series de datos más largas, lo que requeriría un esfuerzo más exigente en la inversión de muestreo, para obtener predicciones adecuadas utilizando estas metodologías de series temporales

Technical-economic management of ruminant farms in Navarra: trends, evolution and prospects

Ponencia presentada a la 51 Reunión Científica de la SEEP celebrada en la Escuela Superior de Ingenieros Agrónomos de la Universidad Pública de Navarra entre el 14 y el 18 de mayo de 2012.Los Institutos Técnicos y de Gestión comenzaron a trabajar en 1981 en el análisis y asesoramiento de gestión a las explotaciones ganaderas de Navarra. En una primera etapa la información recogida para este objetivo fue de carácter técnico fundamentalmente y, posteriormente, se amplió tanto el volumen de información recopilada como el ámbito de estudio, pasando de trabajar con el rebaño a trabajar con la explotación en su conjunto. En la actualidad se dispone de series de datos desde 1986 que permiten estudiar la evolución de la productividad, los precios, los costes y los resultados de las diferentes especies de ganadería de rumiantes y en sus diferentes orientaciones productivas (OP). Las principales de entre ellas que existen en Navarra son: i) vacuno de leche (VL), ii) vacuno de carne (VC), iii) ovino de leche (OL), iv) ovino de carne (OC). En este trabajo se repasan, en primer lugar, los censos y la tipología de las explotaciones. Posteriormente, utilizando los resultados de gestión técnico-económica y analizando tanto su evolución en el pasado como la situación actual, se hace un recorrido por los principales factores que inciden sobre las diferentes estrategias adoptadas por los ganaderos y sobre la rentabilidad de su actividad. Para terminar, se presenta una propuesta y algunos resultados de los nuevos enfoques que se están desarrollando desde INTIA para que la gestión pueda ofrecer un diagnóstico de las explotaciones ganaderas más integral y más adaptado a las exigencias futuras.The Technical and Management Institutes started to work in 1981 in the advice and analysis of farm’s management in Navarra. In a first stage, the information collected for this purpose was technical, mainly to increase both the volume of information and the study area, going from working at the herd level to the farm level. Data set collected from 1986 till nowadays of different ruminant species and productive orientations, allows the study of the evolution of the productivity, the prices and the costs of i) dairy cattle, ii) beef, iii) dairy sheep and iv) sheep meat. In this paper we review, first, the evolution of censuses and the typology of farms. Using the technical-economic management results we analyze the evolution, the current situation, the main factors that affect the different strategies adopted by farmers, and the profitability of their business. Finally, we present a proposal and some results of new approaches that INTIA is beginning to work in order to adapt ruminant livestock management to future requirements

Thermoforming of thermoset composites manufactured by pultrusion

In this work the development of a profile manufactured by pultrusion and thereafter curved by thermoforming is presented. The pultrusion profile is based on a new thermostable epoxy resin with dynamic bonds capable of being reprocessed, repaired and recycled thanks to the incorporation of reversible links within its reticulated structure (3R Technology). Being a resin that contains dynamic bonds, the cured composite shows unexpected properties for thermosetting materials. In a first phase, a new resin/hardener formulation processable by pultrusion with a viscosity, adhesion to the fibre and speed of curing similar to a conventional formulation have been developed and in a second phase, taking into account the properties of the new composite material, the parameters of the thermoforming process (pressure, temperature or speed of thermoforming) have been analysed and optimized. Thanks to the combination of pultrusion and thermoforming processes, longitudinal 3R composite profiles acquire a new curved geometry defined by the design of a mould. In this way, the thermoforming of the straight profiles will allow manufacturing curved parts from profiles of thermostable composites with high mechanical performance manufactured by pultrusion in medium-high rates, typical of the automotive sector. Additionally, it will be shown that the profiles manufactured using these composites can be recycled, reducing the amount of waste generated and offering these materials a second useful life