Search results for "fishe"
showing 10 items of 2001 documents
Simultaneous optimization of harvest schedule and measurement strategy
2013
In many recent studies, the value of forest inventory information in the harvest scheduling has been examined. Usually only the profitability of measuring simultaneously all the stands in the area is examined. Yet, it may be more profitable to concentrate the measurement efforts to some subset of them. In this paper, the authors demonstrate that stochastic optimization can be used for defining the optimal measurement strategy simultaneously with the harvest decisions. The results show that without end-inventory constraints, it was most profitable to measure the stands that were just below the medium age. Measuring the oldest stands was not profitable at all. It turned out to be profitable t…
Gill area explains deviations from body size–metabolic rate relationship in teleost fishes
2022
Whether gill area constrains fish metabolism through oxygen limitation is a debated topic. Here, the authors provide insights into this question by analysing mass-specific metabolic rates across 44 teleost fishes extracted from FishBase. They explore whether species deviations from metabolic rates predicted by body mass can be explained by species gill area. They show that the gill area explains c. 26%–28% of species-level deviations from mass-specific metabolic rates. Their findings suggest that gill area might indeed be one of the factors limiting metabolic rate in fishes.
Honey Bee Pollen in Meagre (Argyrosomus regius) Juvenile Diets: Effects on Growth, Diet Digestibility, Intestinal Traits, and Biochemical Markers Rel…
2020
This research aimed to evaluate the effects of the inclusion of honey bee pollen (HBP) in meagre (Argyrosoumus regius) juveniles&rsquo
Farming intensity indirectly reduces crop yield through negative effects on agrobiodiversity and key ecological functions
2022
International audience; Farming intensity and landscape heterogeneity influence agrobiodiversity and associated ecological functions. The relative contributions of these agroecosystem components to agricultural production remain unclear because of inter-relations and weather-dependant variations. Using a structural equation modelling approach, we estimated direct and indirect contributions of farming intensity (soil management, pesticide use and fertilisation) and landscape heterogeneity (of semi-natural covers and crop mosaic) to cereal crop production, in 54 fields (mostly wheat), in two years (24 and 30 fields). Indirect effects were evaluated through agrobiodiversity (carabid and plant …
Effects of UV Radiation and Diet on Polyunsaturated Fatty Acids in the Skin, Ocular Tissue and Dorsal Muscle of Atlantic Salmon (Salmo salar) Held in…
2010
Article published in Photochemistry and Photobiology, 86 (4): 909-919 JUL-AUG 2010 The effect of UV radiation (UVR) on juvenile Atlantic salmon (Salmo salar) was assessed by measuring the fatty acid (FA) profiles of muscle, dorsal and ventral skin, and ocular tissues following 4-month long exposures to four different UVR treatments in outdoor rearing tanks. Fish were fed two different diets (Anchovy- and Herring-oil based) that differed in polyunsaturated fatty acid (PUFA) concentrations. Anchovy-fed salmon had higher concentrations of ALA (alpha-linoleic acid; 18:3n-3), EPA (eicosapentaenoic acid; 20:5n-3) and DPA (docosapentaenoic acid, 22:5n-3) in their muscle tissues than fish fed the H…
Pathways for the amplification of agroecology in African sustainable urban agriculture
2020
A growing awareness that highly intensified agricultural systems have made a substantial worldwide contribution to the worsening of the resilience capacity of natural ecosystems has, over the last twenty years, brought general attention to agroecological management models. This aspect is even more evident in industrial agriculture, which is based on the use of multiple chemical products derived from non-natural synthesis. In more developed countries, a new idea of ecology linked to agricultural production has been increasingly developed and, for this reason, there has been a greater diffusion of differentiated agricultural models taking into consideration the environmental impact of product…
From Analysis to Formulation of Strategies for Farm Advisory Services (Case Study: Valencia – Spain). an Application through Swot and Qspm Matrix
2019
Abstract European agriculture should meet new increasing internal and contextual challenges. For example, the reform of the Common Agricultural Policy in 2003 introduced the cross-compliance, among other novelties, as compulsory for farmers. To better meet this and other requirements, Member States had to set up the so-called Farm Advisory System, operational across the European Union in 2007. From a sample of actors involved in the provision of farm advisory services in the region of Valencia (Spain), the present study aimed to identify the most appropriate strategies to implement such services. SWOT method has been applied to examine the internal and external environment. Based on this di…
Regional Farmers’ Perception and Societal Issues in Vineyards Affected by High Erosion Rates
2021
We explore the current situation in a viticultural region in Eastern Spain from a holistic and multifaceted research approach, which allowed us to understand the biophysical conditions, economic cost, social impact, and perception of the farmers’ community to the use of catch crops. A survey of the perception of the farmers, and an assessment of the biophysical impact of catch crops (CC) and tillage (C = Control plot) on soil organic matter, bulk density, infiltration capacity (single ring infiltrometer), and runoff generation and soil erosion (rainfall simulation experiments) was carried out. Two representative fields as study sites were selected in Les Alcusses valley, within Els Alforins…
Alternative analysis of transient infiltration experiment to estimate soil water repellency
2019
The repellency index (RI) defined as the adjusted ratio between soil‐ethanol, Se, and soil‐water, Sw, sorptivities estimated from minidisk infiltrometer experiments has been used instead of the widely used water drop penetration time and molarity of ethanol drop tests to assess soil water repellency. However, sorptivity calculated by the usual early‐time infiltration equation may be overestimated as the effects of gravity and lateral capillary are neglected. With the aim to establish the best applicative procedure to assess RI, different approaches to estimate Se and Sw were compared that make use of both the early‐time infiltration equation (namely, the 1 min, S1, and the short‐time linear…