Heat Treatment Improvement of Dairy Products via Ohmic Heating Processes : Thermal and Hyrodynamic Effect on Fouling

Fouling and consequently cleaning of heat exchangers in the dairy industry are nowadays a significant issue still not solved for the processing of quite a large variety of products. Ohmic heating processes for food products a priori are well known to minimize the fouling phenomenon due to a totally different way of heating food by admitting the current directly in the product. Such a technology could be a good alternative to counter both fouling and cleaning aspects when pasteurizing or sterilizing dairy desserts known to generate large amounts of soil on heated surfaces. The aim of this experimental study was to investigate the respective roles of both the hydrodynamic parameters and surface electrode temperatures on the fouling phenomenon when heating a simple dairy mix designed to mimic dairy product behaviors

Ecology, behaviour and management of the European catfish

The extreme body sizes of ‘megafishes’ associated with their high commercial values and recreational interests have made them highly threatened in their native range worldwide by human-induced impacts such as overexploitation. Meanwhile, and because of the aforementioned interests, some megafishes have been introduced outside of their native range. A notable exampled is the European catfish (Silurus glanis), one of the few siluriforms native from western Europe and among the 10 largest freshwater fish worldwide, attaining a total length over 2.7 m and a documented mass of 130 kg. Its distinct phylogeny and extreme size imply many features rare among other European fish such as peculiar behaviours (massive aggregations, beaching), consumption of large bodied prey, fast growth rate, long lifespan, high fecundity, nest guarding and large eggs. The spread of the species is likely to continue due to illegal introduction coupled with natural range extension due to current and future climate change. Based on these attributes and potential future risks, this introduced giant predator in European fresh waters could provide a novel model species of high utility for testing aspects of ecological and invasion theory and associated hypotheses. Here, we reviewed the most recent knowledge on the current distribution and the ecology of the species to understand how this can help advance our understanding of biological invasions. We also identified key research questions that should help stimulating new research on this intriguing, yet largely unknown, species and, more generally, on the ecology of invasive species

Guidelines for the definition of operational management units

The objective of fisheries management is the sustainable exploitation of the fish resources over the extent of their spatial distribution. Along with the Common Fisheries Policy (CFP) objectives, the socio-economic viability of the fisheries exploiting the resource is also to be achieved. To reach these aims, managers need to define the management units they are going to work with. For the purpose of GEPETO project, we define a management unit (MU) as the set of fishing fleets exploiting a common pool of fish resources with strong spatial overlapping and sharing of habitats, which make them being typically fished together. In other words, a MU is the set of fishing fleets exploiting a common fish community over their spatial distribution. MUs have to be defined by the fish community, by the spatial range of distribution of the fish community, and by the set of fishing fleets sharing the exploitation of the fish communityL'objectif de gestion de la pêche est l'exploitation durable des ressources halieutiques sur l'étendue de leur répartition spatiale. Avec la nouvelle Politique Commune de la pêche (PCP) l' objectif de la viabilité socio-économique des pêcheries exploitant la ressource doit également être réalisé. Pour l'atteindre, les gestionnaires doivent définir des unités de gestion. Les partenaires du projet GEPETO, définissent une unité de gestion (MU) comme l'ensemble des flottes de pêche exploitant un pool commun de ressources halieutiques disponibles dans des habitats communs, ce qui les rend très imbriquées. En d'autres termes, un MU est l'ensemble des flottes de pêche exploitant une communauté de poissons ordinaires sur leur répartition spatiale. La MU peu être définie par la communauté de poissons, par la gamme spatiale de la distribution de la communauté de poissons, et par l'ensemble des flottes de pêche qui partagent l'exploitation de la communauté de poissons

Etude des performances thermiques d'un chauffage ohmique pour la stérilisation UHT du lait - Définition d'un critère d'encrassement.

In : 6ième Colloque PROSETIA, Versailles – St Cyr, 19-21 Mars 2001.Etude des performances thermiques d'un chauffage ohmique pour la stérilisation UHT du lait - Définition d'un critère d'encrassement. . 6. Colloque Prosetia. Procédés de séparation et de transformation en industrie alimentair

Sperm design and variation in the New World blackbirds (Icteridae)

Post-copulatory sexual selection (PCSS) is thought to be one of the evolutionary forces responsible for the rapid and divergent evolution of sperm design. However, whereas in some taxa particular sperm traits are positively associated with PCSS, in other taxa, these relationships are negative, and the causes of these different patterns across taxa are poorly understood. In a comparative study using New World blackbirds (Icteridae), we tested whether sperm design was influenced by the level of PCSS and found significant positive associations with the level of PCSS for all sperm components but head length. Additionally, whereas the absolute length of sperm components increased, their variation declined with the intensity of PCSS, indicating stabilizing selection around an optimal sperm design. Given the diversity of, and strong selection on, sperm design, it seems likely that sperm phenotype may influence sperm velocity within species. However, in contrast to other recent studies of passerine birds, but consistent with several other studies, we found no significant link between sperm design and velocity, using four different species that vary both in sperm design and PCSS. Potential reasons for this discrepancy between studies are discussed