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81.
The aims of this study was to assess the effect of two lactic acid bacteria (LAB), Lactobacillus curvatus and Leuconostoc mesenteroides, originally isolated from gastrointestinal (GI) tract of beluga (Huso huso) and Persian sturgeon (Acipenser persicus), respectively, on growth, survival and digestive enzyme (amylase, lipase and protease) activities and the population level of LAB in the GI tract. The treatments included 10 different groups; control, separate supplements of Lcurvatus and Leumesenteroides at three different counts [2 × 109, 5 × 109 and 9 × 109 colony forming units (CFU) per gram food] and three combinations of the two LAB (2 × 109 + 2 × 109, 5 × 109 + 5 × 109 and 9 × 109 + 9 × 109 CFU per gram food). The bacteria used in this study were added in lyophilized form to chopped Chironomidae. In the beluga study, highest specific growth rate, survival and improved intestinal enzyme activities were noted in the rearing group fed 9 × 109 L. curvatus per gram food. In Persian sturgeon, the inclusion level of 2 × 109 Leu. mesenteroides had similar positive effect. The ability of LAB to colonize the digestive tract seems to involve host specificity, and our bacteriological results are relevant to initiate future probiotic studies in sturgeons and future directions will be discussed.  相似文献   
82.
The results of bulk propagation of Norway spruce for one year are presented. The number of cuttings produced per seedling ranged from 21 to 38 between different families, with a large within-family variation. No clear relationship between family field performance and production of cuttings could be seen. Established cuttings produced more propagules per plant than seedlings in the first propagation. Misting gave about 92% rooting, with no significant differences between different rooting media used. A bulk propagation programme is proposed with a potential production of about 1000–1500 plants per germinated seed within 3 years of sowing.  相似文献   
83.
A profit function was developed to estimate economic values for new efficiency traits for fattening pigs in Norwegian Landrace. These traits were lean meat efficiency (LME) and fat efficiency (FE). LME and FE described how much feed the animal used to produce 1?kg lean meat and fat as a deviation from the mean. Both traits were derived from analysing total feed consumption in a random regression model which included lean meat and fat content of the carcass (FC) as random covariates. In addition, economic values and breeding values were calculated for days from 40 to 100/120?kg live weight (DAYS), lean meat percentage (LMP) and FC. To compare LME and FE with total feed intake (FI), two indexes were constructed. One index included LME, FE, DAYS, LMP and FC and was referred to as breeding goal A and one index included FI, LMP and DAYS and was referred to as breeding goal B. The standardized economic values for LME and FE were 8.9 and 2.9 EUR/σa, respectively. There was a larger variation in the index for breeding goal A (SD?=?5.65) than B (SD?=?3.97). The results suggested that the two efficiency traits had an economic importance in pork production and that there was a potential for increased genetic gain in profit by using breeding goal A compared to breeding goal B.  相似文献   
84.
Abstract

This paper builds on an earlier review by Kinnucan and Wessells (1997) by discussing in some detail product differentiation, market integration, and generic advertising. The goal is to identify approaches and findings in each topical area that would appear to have relevance for aquaculture. Selected applications are given to highlight principles and to demonstrate usefulness.  相似文献   
85.
Consumption of berries from various sources including the genus Ribes has been associated with diverse potential health benefits. The 14 examined cultivars of European gooseberry (R. grossularia L.) contained in various proportions the 3-glucoside (3), 3-rutinoside (4), 3-xyloside (7), 3-O-beta-(6' '-E-caffeoylglucopyranoside) (8), and 3-O-beta-(6' '-E-p-coumaroylglucopyranoside) (10) of cyanidin and the 3-rutinoside (6) and 3-glucoside of peonidin (5). Pigments 3, 4, delphinidin 3-rutinoside (2), delphinidin 3-glucoside (1), and minor amounts of 6, 7, and 10 were found in red flowering currant (R. sanguineum Pursh). Golden currant (R. aureum Pursh) contained 3, 4, and trace amounts of 1, 6, and 7, while alpine currant (R. alpinum L.) contained 3, 4, and trace amounts of 10. The major anthocyanins in two cultivars of jostaberries (R. x nidigrolaria Bauer), 1-4, 8, and 10, reflected that this hybrid contained the major anthocyanins of both parents, black currant and gooseberry. This is the first complete identification of 8 and the ring size of the sugar of 10. Pigment 9 was tentatively identified as cyanidin 3-(6' '-Z-p-coumaroylglucoside). This new pigment occurred in minor amounts (<2%) in all R. grosssularia and R. x nidigrolaria cultivars. No commercially available berries have been reported to contain such high proportions of aromatic acylated anthocyanins as found in the gooseberry cultivars "Sams?", "Hinnom?ki Red", "Taastrup", "Lofthus", and "Glendal", which are in this context the most obvious candidates for consumption, colorant, and breeding programs.  相似文献   
86.
Factors contributing to the texture of fish flesh, including pH, water content, density of fast muscle fibers, and the concentration of collagen and hydroxylysyl pyridinoline (PYD) cross-links, were investigated post-rigor in commercially farmed Atlantic halibut (Hippoglossus hippoglossus L.). The fish was sampled every quarter for a 12 month period from May 2004 to May 2005. Hydroxyproline (HYP) as a measure of collagen and PYD were determined using a high-performance liquid chromatography (HPLC) method. An ANCOVA model with fork length and season as covariates were used to explore the seasonal effects on texture, pH, muscle fiber density, alkaline-insoluble collagen (a-i HYP), alkaline-soluble collagen (a-s HYP), and PYD cross-links. A multiple linear regression (MLR) showed that the most important factors contributing to texture were PYD>water (%)>a-i HYP>fiber density, while pH and a-s HYP did not show any correlation to texture. The contribution of fast muscle fiber density to texture was found to vary between sexes and with the season, contributing more in males and in the spring. The most important parameter affecting texture was PYD, explaining 64% (p<0.001) of the total variation in a linear regression analysis. It is concluded that cross-linking processes are of great importance for the rigidity and strength of the collagen in Atlantic halibut flesh. Farmed halibut should be harvested in the fall or early winter when texture and nutrition are good to obtain optimal quality.  相似文献   
87.
Noninvasive genetic monitoring has the potential to estimate vital rates essential for conservation and management of many species. In a long-term genetic capture-mark-recapture study using scats we evaluated temporal variation in adult survival in a wolverine (Gulo gulo) population in southern Norway. In contrast to most previous studies of large mammals we found evidence for negative density dependence in adult survival in this large carnivore. Both sexes showed the same pattern of density dependence, with higher annual survival rates in adult females than males. In addition, we also found an additive mortality effect of harvesting in the population, resulting in the lowest adult survival rates at a combination of high population density and high harvest rate. The additive effects of density and harvest on adult survival of wolverines have relevance to the conservation and management of solitary carnivores with strong intrasexual territoriality, especially for species where combats among conspecifics can cause serious injury or even mortality.  相似文献   
88.
89.
Transport of volatile hydrocarbons in soils is largely controlled by interactions of vapours with the liquid and solid phase. Sorption on solids of gaseous or dissolved compounds may be important. Since the contact time between a chemical and a specific sorption site can be rather short, kinetic or mass-transfer resistance effects may be relevant. An existing mathematical model describing advection and diffusion in the gas phase and diffusional transport from the gaseous phase into an intra-aggregate water phase is modified to include linear kinetic sorption on gas-solid and water-solid interfaces. The model accounts for kinetic mass transfer between all three phases in a soil. The solution of the Laplace-transformed equations is inverted numerically. We performed transient column experiments with 1,1,2-Trichloroethane, Trichloroethylene, and Tetrachloroethylene using air-dry solid and water-saturated porous glass beads. The breakthrough curves were calculated based on independently estimated parameters. The model calculations agree well with experimental data. The different transport behaviour of the three compounds in our system primarily depends on Henry's constants.  相似文献   
90.
A model strategy that can be used for the study of global distributions of chlorinated hydrocarbons in the environment is presented. In this first approach the number of compartments and processes are kept on a minimum level by only considering the atmosphere, ocean and soil. Important processes are simulated or replaced by simple parameterizations, while processes believed to be less important are temporally omitted. The transport in the atmosphere is simulated by a simple two-dimensional zonally averaged model with a rather coarse resolution of 6 equally spaced latitude zones and 4 vertical layers. The soil is included in the model by dividing the continents into the same latitude zones as the atmosphere, and the land area in each zone into an uncultivated part and a cultivated part where pesticides may be incorporated. A model for tracer transport in the ocean which combines the features of the box and box-diffusion models has been modified for use in this study. Material is exchanged between the compartments by the processes believed to be most important in the real environment. The model is tested by simulating the life cycle of the α and γ isomers of hexachlorocyclohexane in the environment. The emissions of the two isomers are estimated from the total world consumption of HCH, and it is assumed that a fraction of 50% is lost to the atmosphere for long range transport during application or during the first days therefore. Comparison with observations indicates that in spite of the many assumptions and uncertain parameters the model is able to reproduce the atmospheric and oceanic concentration levels of εHCH. The HCH simulation indicates that the presented model strategy is usable when the aim is to increase the understanding of chlorinated hydrocarbons in the global environment. For the prediction of concentration levels in specific areas on the other hand, the present model strategy does not apply. The resolution of the model is too coarse and the simplifications are too extensive for such estimates to be valid.  相似文献   
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