71 research outputs found

    Use of rice protein concentrate in rainbow trout feeding: preliminary results

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    During the past decades, the fishery industry has excessively used the world fish captures to produce fishmeal and fish oil in order to prepare feed for aquaculture diets. This has led to a drastic reduction of several fish populations (Hardy, 1999; FAO, 1999). At present 70% of the oil and 34% of fishmeal obtained from captures are used for aquaculture industry and, if the aquaculture production will continue to increase as predicted, in a short time it will absorb the entire world oil and fish meal production. Moreover, since fish meal still constitutes an important part of the feed formula for cultivated fish and since a further increase of fish meal availability will not be possible (Hardy, 2001), its price is expected to continue to increase (Tacon, 1998)

    A floating cage system for rearing freshwater mussels Anodonta anatina and Unio mancus in Piedmont region (NW Italy)

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    This research represents the first attempt in Italy to develop a cage system for adult freshwater mussel stocking, for extensive farming, that was realized from 2003 to 2005 in NW Italy. Two autochthonous species of Italian freshwater mussel were used: Anodonta anatina and Unio mancus. 5133 mussels were collected and successively stocked in floating cages in 5 different sites in a lake. This study was planned in order to determine the effect of main rearing factors for potential farming: stocking density and cage position in the water column (depth). For each species, the effects of three rearing densities and two water depths were tested. Mussel growth was measured on a monthly basis in each experimental unit throughout the study. The survival rate at the end of the experiment for both species considered was 98.4%. U. mancus resulted to be more resistant to rearing conditions and during the summer the highest mortality was registered for A. anatina. Summer mortality was between 4.8% and 20.5%. Highest mortality in U. mancus was recorded in September 2004 at 1.5 m (3.6±2.4%), while the highest mortality for A. anatina was recorded in September 2003 as 13.3%±3.8% at a depth of 1.5 m. This research showed that cage stocking is a suitable method and the optimal position of cages is at the lake thermocline. The proposed species proved to be easily utilizable for future farming or bioremediation projects, and can readily be reared up to 135 kg m^-3

    Convergence and divergence in the evolution of cat skulls: temporal and spatial patterns of morphological diversity

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    Background: Studies of biological shape evolution are greatly enhanced when framed in a phylogenetic perspective. Inclusion of fossils amplifies the scope of macroevolutionary research, offers a deep-time perspective on tempo and mode of radiations, and elucidates life-trait changes. We explore the evolution of skull shape in felids (cats) through morphometric analyses of linear variables, phylogenetic comparative methods, and a new cladistic study of saber-toothed cats. Methodology/Principal Findings: A new phylogenetic analysis supports the monophyly of saber-toothed cats (Machairodontinae) exclusive of Felinae and some basal felids, but does not support the monophyly of various sabertoothed tribes and genera. We quantified skull shape variation in 34 extant and 18 extinct species using size-adjusted linear variables. These distinguish taxonomic group membership with high accuracy. Patterns of morphospace occupation are consistent with previous analyses, for example, in showing a size gradient along the primary axis of shape variation and a separation between large and small-medium cats. By combining the new phylogeny with a molecular tree of extant Felinae, we built a chronophylomorphospace (a phylogeny superimposed onto a two-dimensional morphospace through time). The evolutionary history of cats was characterized by two major episodes of morphological divergence, one marking the separation between saber-toothed and modern cats, the other marking the split between large and small-medium cats. Conclusions/Significance: Ancestors of large cats in the ‘Panthera’ lineage tend to occupy, at a much later stage, morphospace regions previously occupied by saber-toothed cats. The latter radiated out into new morphospace regions peripheral to those of extant large cats. The separation between large and small-medium cats was marked by considerable morphologically divergent trajectories early in feline evolution. A chronophylomorphospace has wider applications in reconstructing temporal transitions across two-dimensional trait spaces, can be used in ecophenotypical and functional diversity studies, and may reveal novel patterns of morphospace occupation

    An ecological study on the relationship between supply of beds in long-term care institutions in Italy and potential care needs for the elderly

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    <p>Abstract</p> <p>Background</p> <p>The ageing population in Europe is putting an ever increasing demand on the long-term care (LTC) services provided by these countries. This study analyses the relationship between the LTC institutional supply of beds and potential care needs, taking into account the social and health context, the supply of complementary and alternative services, along with informal care.</p> <p>Methods</p> <p>An observational, cross-sectional, ecological study was carried out. Statistical data were obtained from the Italian National Institute of Statistics and Ministry of Health. Indicators, regarding 5 areas (Supply of beds in long term care institutions, Potential care needs, Social and health context, Complementary and alternative services for the elderly, Informal care), were calculated at Local Health Unit (LHU) level and referred to 2004.</p> <p>Two indicators were specifically used to measure supply of beds in long term care institutions and potential care needs for the elderly. Their values were grouped in tertiles. LHU were classified according to the combination of tertiles in three groups: A. High level of supply of beds in long term care institutions associated with low level of potential care needs; B. Low level of supply of beds in long term care institutions associated with high level of potential care needs; C. Balanced level of supply of beds in long term care institutions with potential care needs. For each group the indicators of 5 areas were analysed.</p> <p>The Index Number (IN) was calculated for each of these indicators.</p> <p>Results</p> <p>Specific factors that need to be carefully considered were highlighted in each of the three defined groups. The highest level of alternative services such as long-stay hospital discharges in residence region (IN = 125), home care recipients (HCR) (IN = 123.8) were reported for Group A. This group included North regions. The highest level of inappropriate hospital discharges in (IN = 124.1) and out (IN = 155.8) the residence region, the highest value of families who received help (IN = 106.4) and the lowest level of HCR (IN = 68.7) were found in Group B. South regions belong to this group. The highest level of families paying a caregiver (IN = 115.8) was shown in Group C. Central regions are included in third group.</p> <p>Conclusion</p> <p>Supply of beds in long term care institutions substantially differs across Italian regions, showing in every scenario some imbalances between potential care needs and other studied factors. Our study suggests the need of a comprehensive rethinking of care delivery "system".</p
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