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We take advantage of our knowledge of the neural circuitry of reward to investigate a puzzling economic phenomenon: Why do people overbid in auctions? Using functional magnetic resonance imaging (fMRI), we observed that the social competition inherent in an auction results in a more pronounced blood oxygen level-dependent (BOLD) response to loss in the striatum, with greater overbidding correlated with the magnitude of this response. Leveraging these neuroimaging results, we design a behavioral experiment that demonstrates that framing an experimental auction to emphasize loss increases overbidding. These results highlight a role for the contemplation of loss in understanding the tendency to bid "too high." Current economic theories suggest overbidding may result from either "joy of winning" or risk aversion. By combining neuroeconomic and behavioral economic techniques, we find that another factor, namely loss contemplation in a social context, may mediate overbidding in auctions.  相似文献   
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Given the high unit value of live American lobsters (Homarus americanus), a non‐destructive field method to assess physiological state is desirable during out‐of‐water transport conditions. This study compared an Uricon® specific gravity refractometer, with a commercial veterinary blood analyser (Vet‐Test), as a method for determining the blood total protein concentration in live, out‐of‐water individuals. Regression analysis of R2 = 0.8641 (n = 64) was observed in determination of blood total protein concentration, y = 0.0036x + 1.0163 where x is the protein concentration in mg dL?1 in Vet‐Test. Our results (R2 = 0.864, SE ± 0.003) support the results (R2 = 0.985) of the previous study conducted by Leavitt & Bayer (1977 ) in which serum total protein was compared with the refractometric method. We therefore confirm that the refractometric method can be used as a reliable method to indicate health of a lobster by measuring the blood total protein concentration. The results show good correlation between the protein concentrations observed using the refractometric method and a Vet‐Test blood chemistry analyser. anova analysis was significant between the protein refractometer and the Vet‐Test (P < 0.05). Although protein concentration units obtained from both methods were different the results followed the same trends. Refractometry as a method is reliable to determine blood total protein concentrations in the American lobster. Consequently, a refractometric method can be used directly by commercial growers and distributors to assess responses to holding facility conditions and to feeding regimes. Whole blood protein concentrations may provide more information than serum protein concentrations as measured in the study of Leavitt & Bayer (1977 ).  相似文献   
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Ozbay E 《Science (New York, N.Y.)》2006,311(5758):189-193
Electronic circuits provide us with the ability to control the transport and storage of electrons. However, the performance of electronic circuits is now becoming rather limited when digital information needs to be sent from one point to another. Photonics offers an effective solution to this problem by implementing optical communication systems based on optical fibers and photonic circuits. Unfortunately, the micrometer-scale bulky components of photonics have limited the integration of these components into electronic chips, which are now measured in nanometers. Surface plasmon-based circuits, which merge electronics and photonics at the nanoscale, may offer a solution to this size-compatibility problem. Here we review the current status and future prospects of plasmonics in various applications including plasmonic chips, light generation, and nanolithography.  相似文献   
4.
The culture of the Eastern oyster (Crassostrea virginica) in containment gear has become a viable component of restoration programs in many states on the East Coast of the United States, and it has been suggested that these operations may provide many of the same ecological services as natural or restored reefs. Our two-part study comparing the diversity and abundance in macro-epifaunal communities associated with a sub-tidal-created oyster reef and ‘modified rack and bag’ cage system (Part I) and floating oyster cages for restoration (Part II) occurred over the summer and fall of 2006 and 2007, respectively. In Part I, a greater total abundance and species richness (P < 0.05) was found to be associated with the cages, but greater evenness (P < 0.05) was found on the reef. No significant difference (P > 0.05) was found in species diversity according to Simpson’s index by habitat type, but it was significant (P < 0.05) by month. These samples were dominated by naked goby (Gobisoma bosc) and Atlantic mud crab (Panopeus herbstii). Spaghetti worm (Ampharetidae, P < 0.01), sheepshead (Archosargus probatocephalus, P < 0.01), blue crab (Callinectes sapidus, P < 0.01), grey snapper (Lutjanus griseus, P < 0.05), gag grouper (Mycteroperca microlepis, P < 0.01), and Atlantic oyster drill (Urosalpinx cinera, P < 0.05) were unique to the cages, while the skilletfish (Gobiesox strumosus) was unique to the reef. Part II revealed that the floating cages supported 13 species of fish and invertebrates, although no significant differences in species richness, evenness, or diversity were found by month or by bay area (P > 0.05). These results suggest that created reefs in conjunction with ‘rack and bag’ cage systems, as well as floating cage systems, support ecologically and economically important macro-epifauna, even at very small scales.  相似文献   
5.
Eastern oyster, Crassostrea virginica is a keystone species in many estuarine bays. They clean the water by filtering out suspended particulates from the water column, while their reefs serve as valuable habitat for many ecologically and economically important macrofaunal species. However, with the ever-increasing development along our coastlines, the oyster population throughout the Mid-Atlantic region has plummeted as a result of overharvesting, extreme eutrophication, and disease. In response to this detrimental decline, many conservation organizations in the area have developed community-involvement programs commonly referred to as ‘oyster gardening’ to help restore the oyster population, while instilling within the community a strong sense of stewardship for their bays. Although the oyster gardening program in Delaware is relatively new, its popularity has grown tremendously. It is the hope of many Delaware residents that the reintegration of oysters into the Inland Bays will help to return their bays to the state of health in which they once were. Despite the expansion, further development of designated reef area is necessary to ensure the successful proliferation of C. virginica in Delaware’s Inland Bays.  相似文献   
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This study evaluated the rate of sedimentation from water under various salinities, over a time period of 72 h. The particles come from soils that are commonly found in shrimp growing areas of Alabama: Black Belt Prairie, Piedmont Plateau, and Upper Coastal Plain. Different salinity treatments and settling times resulted in significant differences (P≤ 0.05) in the reduction of turbidity and TSS for each soil type. Solutions containing 2 ppt salinity had a similar rate of turbidity reduction as the solutions with 5, 10, or greater ppt treatments. Concentrations of turbidity and TSS decreased rapidly between 1 and 12 h of sedimentation; very little decline was observed during the time intervals 12–72 h. Higher salinity treatments yielded settling patterns similar to the 2 ppt salinity treatment. After 1 h, turbidity was removed by 65% in the control compared with 85% salinity treated samples. Variations in turbidity and TSS among the three sediments suggest that finer particles, the Piedmont Plateau soils, settled at a slower rate than larger particles. This difference occurs because the percentage of turbidity and TSS removed was significantly higher in mineralized waters compared to freshwater. Therefore, a small amount of salt, 2 ppt, can be used in pond aquaculture treatments to reduce the turbidity and TSS concentrations in shrimp ponds.  相似文献   
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