Search results for "Fish"
showing 10 items of 3164 documents
The sustainability of the Sicilian seafood chain: Innovation, organizational models and value chain
2015
fisheries sector, organizational change, value chain, innovation To what extent and how the acquisition of new innovative processes can affect the structure and roles of the actors within the seafood sector chain? What are the possible effects along the entire value chain and on the distribution of this value to those who have contributed to generate it ? The proposed analysis aims to clarify some aspects of these complex issues whose implications may affect the future and the economic sustainability of the fisheries sector in Sicily. The related economic literature investigates the role of organizational change management on improving the performance of companies engaged in the launch of i…
The Family Business in the Fishing District of Mazara del Vallo. Critical issues and Dynamics
2016
This work-in-progress paper presents the early results of a survey aiming to understand the relationship between family firms and regional development in contemporary economic, by examining the negative effects of “family inertia” on the acquisition of dynamic capabilities necessary to enhance competitiveness and establish inter-firm cooperation strategies in family businesses in the context of an industrial district. Family firms are acknowledged for playing an important role in the creation, organization, and allocation of regional resources and in regional processes. Industrial districts are recognized as fertile fields for the development of inter-firm interrelations that may produce po…
The organic carbon derived from sewage sludge as a key parameter determining the fate of trace metals.
2007
8 pages; International audience; In a sandy agricultural soil of south-west of France, continuously cultivated with maize and amended with sewage-sludge over 20 years, the behavior of three trace metals (Cu, Pb, and Zn) was studied during the sludge applications (1974-1993) and after its cessation (1993-1998). Using the delta13C analysis, the dynamics of different sources of organic matter were followed in order to elucidate the influence of the sludge-derived organic matter on the fate of trace metals in the soil and its particle size fractions. This study revealed that sludge-derived organic matter contributed to the formation of macroaggregates through the binding of preexisting microagg…
Disentangling conditional effects of multiple regime shifts on Atlantic cod productivity
2020
AbstractRegime shifts are increasingly prevalent in the ecological literature. However, definitions vary, and many detection methods are subjective. Here, we employ an operationally objective means of identifying regime shifts, using a Bayesian online change-point detection algorithm able to simultaneously identify shifts in the mean and(or) variance of time series data. We detected multiple regime shifts in long-term (59-154 years) patterns of coastal Norwegian Atlantic cod (>70% decline) and putative drivers of cod productivity: North Atlantic Oscillation (NAO); sea-surface temperature; zooplankton abundance; fishing mortality (F). The consequences of an environmental or climate-relate…
The influence of strain localisation on the rotation behaviour of rigid objects in experimental shear zones
2002
Abstract Mica fish and tourmaline fish from natural mylonites were analysed in thin section to determine their orientation distribution. They are oriented with their long axes tilted with respect to the mylonitic foliation, and fish with a small aspect ratio exhibit a slightly larger angle than fish with a large aspect ratio. This orientation seems to be a stable orientation for the mica and tourmaline fish. Analogue experiments with two rheologically different matrix materials were performed to explain the data. One material was PDMS, a linear viscous polymer. The other was tapioca pearls, a granular material with low cohesion and Mohr–Coulomb type behaviour. In contrast to a fairly homoge…
Vertical distribution of two sympatric labrid fishes in the Western Mediterranean and Eastern Atlantic rocky subtidal: local shore topography does ma…
2011
Changes in the shore topography (e.g. slope) occur at a scale of hundreds of meters in several locations in the Lusitanian and the Mediterranean Sea provinces. We tested whether differences in the bottom inclination might affect the vertical distribution patterns of two sympatric coastal labrid fishes, the rainbow wrasse Coris julis and the ornate wrasse Thalassoma pavo. Visual censuses were used to determine the distribution and abundance of these labrid species in high (‡30� ) and low (£3� ) slope rocky substrates covered by brown macroalgae and at two different depths (shallow, 4‐7 m, and deep 14‐20 m). Pectoral fin aspect ratio was used as an estimate of swimming performance to potentia…
Biochemical Responses of European Sea Bass (Dicentrarchus labrax L.) to the Stress Induced by Off Shore Experimental Seismic Prospecting
1999
The paper reports the results of an experimental seismic survey in the open sea by an air gun, carried out to evaluate the effects of air gun acoustic waves on marine animals. Air gun blast exposition was found to have a marked influence on confined Dicentrarchus labrax. Our data, in fact, demonstrated a biochemical response to acoustic stress induced by air gun blasts. Variations of cortisol, glucose, lactate, AMP, ADP, ATP and cAMP in different tissues of D. labrax, indicate that fish have a typical primary and secondary stress response after air gun detonations. Radiography indicates that air gun blasts do not induce any macroscopic effect on skeletal apparatus. The variations of biochem…
Ventastega curonica and the origin of tetrapod morphology.
2008
The gap in our understanding of the evolutionary transition from fish to tetrapod is beginning to close thanks to the discovery of new intermediate forms such as Tiktaalik roseae. Here we narrow it further by presenting the skull, exceptionally preserved braincase, shoulder girdle and partial pelvis of Ventastega curonica from the Late Devonian of Latvia, a transitional intermediate form between the 'elpistostegids' Panderichthys and Tiktaalik and the Devonian tetrapods (limbed vertebrates) Acanthostega and Ichthyostega. Ventastega is the most primitive Devonian tetrapod represented by extensive remains, and casts light on a part of the phylogeny otherwise only represented by fragmentary ta…
Siderophores and related outer membrane proteins in Vibrio spp. which are potential pathogens of fish and shellfish
1991
. A total of eight reference strains and 43 environmental isolates of Vibrio species that are potential fish pathogens, were assayed for the production and utilization of siderophores. Chemical and biological assays indicated that all species produced phenolate compounds and only some strains of V. cholerae non-O1, V. parahaemolyticus and V. fluvialis produced hydroxamates. Bioassays indicated that all species produced compounds that stimulated the growth of the homologous and the heterologous species in low-iron media. The catechol-type siderophores produced may be functionally related to enterobactin as demonstrated by bioassays with enterobactin-deficient mutants. However, the chromatogr…
Perception of illusory surfaces and contours in goldfish
2007
Goldfish(Carassius auratus)were trained to discriminate triangles and squares using a two choice procedure. In the first experiment, three goldfish were trained with food reward on a black outline triangle on a white background, while a black outline square was shown for comparison. In transfer tests, a Kanizsa triangle and a Kanizsa square were presented, perceived by humans as an illusory triangle- or square-shaped surface of slightly higher brightness than the background. The choice behavior in this situation indicates that goldfish are able to discriminate between both figures in almost the same way as in the training situation. In control experiments goldfish did not discriminate betwe…