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271.
A key element in making our food systems more efficient is the reduction of food losses across the entire food value chain. Nevertheless, food losses are often neglected. This paper quantifies food losses in Switzerland at the various stages of the food value chain (agricultural production, postharvest handling and trade, processing, food service industry, retail, and households), identifies hotspots and analyses the reasons for losses. Twenty-two food categories are modelled separately in a mass and energy flow analysis, based on data from 31 companies within the food value chain, and from public institutions, associations, and from the literature. The energy balance shows that 48% of the total calories produced (edible crop yields at harvest time and animal products, including slaughter waste) is lost across the whole food value chain. Half of these losses would be avoidable given appropriate mitigation measures. Most avoidable food losses occur at the household, processing, and agricultural production stage of the food value chain. Households are responsible for almost half of the total avoidable losses (in terms of calorific content).  相似文献   
272.
We examined the feeding ecology and niche segregation of the ten most abundant fish species caught by longline operations off eastern Australia between 1992 and 2006. Diets of 3,562 individuals were examined. Hook timer data were collected from a further 328 fish to examine feeding behaviour in relation to depth and time of day. Prey biomass was significantly related to predator species, predator length and year and latitude of capture. Although the fish examined fed on a mix of fish, squid and crustacea, fish dominated the diet of all species except small albacore (Thunnus alalunga) which fed mainly on crustacea and large swordfish (Xiphias gladius) and albacore which fed mainly on squid. Cannibalism was observed in lancetfish (Alepisaurus spp.). Multidimensional scaling identified three species groups based on their diet composition. One group consisted of yellowfin tuna (T. albacares), striped marlin (Tetrapturus audax) and dolphinfish (Coryphaena hippurus); a second group consisted of bigeye tuna (T. obesus), swordfish and albacore; and a third consisted of southern bluefin tuna (T. maccoyii) and blue shark (Prionace glauca). Of note was the separation of mako shark (Isurus oxyrhynchus) and lancetfish from all other predators. Prey length generally increased with increasing predator length although even large predators fed on a wide range of prey lengths including very small prey. Overall, differences in prey type and size, feeding times and depths were noted across the range of species examined to the extent that predators with overlapping prey, either in type or size, fed at different times of the diel period or at different depths. Taken together these data provide evidence for feeding niche segregation across the range of oceanic top predators examined.  相似文献   
273.
274.
Environmental Science and Pollution Research - One essential step of museum and clinical specimen preservation is immersion in a fixative fluid to prevent degradation. Formalin is the most largely...  相似文献   
275.
276.
We review the risk of norovirus (NoV) infection to the human population from consumption of contaminated shellfish. From a UK perspective, risk is apportioned for different vectors of NoV infection within the population. NoV spreads mainly by person-to-person contact or via unsanitary food handling. NoV also enters the coastal zone via wastewater discharges resulting in contamination of shellfish waters. Typically, NoV persists in the marine environment for several days, with its presence strongly linked to human population density, wastewater discharge rate, and efficacy of wastewater treatment. Shellfish bioaccumulate NoV and current post-harvest depuration is inefficient in its removal. While NoV can be inactivated by cooking (e.g. mussels), consumption of contaminated raw shellfish (e.g. oysters) represents a risk to human health. Consumption of contaminated food accounts for 3–11% of NoV cases in the UK (~74,000 cases/year), of which 16% are attributable to oyster consumption (11,800 cases/year). However, environmental and human factors influencing NoV infectivity remain poorly understood. Lack of standard methods for accurate quantification of infective and non-infective (damaged) NoV particles represent a major barrier, hampering identification of an appropriate lower NoV contamination limit for shellfish. Future management strategies may include shellfish quality assessment (at point of harvest or at point of supply) or harvesting controls. However, poor understanding of NoV inactivation in shellfish and the environment currently limits accurate apportionment and risk assessment for NoV and hence the identification of appropriate shellfish or environmental quality standards.  相似文献   
277.
This study examined the relationship between environmental concern and ratings of acceptability of environmental impacts among visitors at two national park settings. Based on the concept of a social ecological paradigm shift, it was hypothesized that individuals with greater levels of environmental concern are less accepting of environmental impacts in national parks than individuals with lesser degrees of concern. Sample data came from Cape Lookout National Seashore (N=392) and Moores Creek National Battlefield (N=236), two national park units in the south-eastern U.S.A. Environmental concern was measured by the New Ecological Paradigm scale. Acceptability was measured by visitor responses to 25 items covering different types of environmental park impacts. Analysis of variance and Tukey's means comparison procedure were used to test for differences between groups defined by levels of environmental concern on impact acceptability. Significant relationships were found between environmental concern and 15 of the 25 specific impacts in the Cape Lookout sample and 13 significant relationships were found in the Moores Creek sample. However, the relationships between environmental concern and acceptability varied somewhat across the two samples. These findings suggested that individuals with greater environmental concern were less accepting (or tolerant) of certain types of park impacts, while individuals with lesser degrees of environmental concern were more accepting of certain park impacts. Differences across the study settings were attributed to the different orientations of park visitors between the two national park units and recency effects. While the data reported are preliminary, they should be informative for park management purposes, particularly in the determination of standards for park impacts.  相似文献   
278.
The teratogenicity of the diphenyl ether herbicide bifenox [2,4-dichlorophenyl 3'-carboxymethyl-4'-nitrophenyl ether] was compared to that of nitrofen [2,4-dichlorophenyl 4'-nitrophenyl ether] in rats and in mice. Neither compound increased prenatal mortality in mice. Because nitrofen causes both malformations that are compatible with survival to weaning and a high incidence of perinatal (but not of fetal) mortality, emphasis was placed on postnatal parameters of bifenox toxicity. In rats, bifenox caused a low incidence of "bloody tears", but it did not decrease survival to term or to weaning in rats or mice, and did not reduce Harderian gland weight in mice. Because the weight of the Harderian glands is a more objective measure of their status than is the presence of an eye discharge, it is concluded that bifenox is not teratogenic at the levels administered. Nitrofen decreased litter size, pup weight, and Harderian gland weight in mice.  相似文献   
279.
Deer hunter satisfaction is investigated from two perspectives, (1) satisfaction with the hunt/harvest and (2) satisfaction with the overall hunting trip experience. Regression analysis is used to determine what variables best predict satisfaction with the hunt and the hunting experience. Results indicate that animal population variables (number of deer seen, shot at, bagged) are the best determinants of a quality deer hunt, while environmental (outdoors) and social (crowding and hunter behavior) are the best predictors of a quality hunting trip experience. Wildlife managers and researchers need to realize that deer hunters view the hunt/harvest as different from the hunting trip experience and need to manage for both aspects of hunter satisfaction.  相似文献   
280.
Phytoremediation of pollutants in soils is an emerging technology, using different soil-plant interaction properties. For organic pollutants, such as polycyclic aromatic hydrocarbons (PAHs), phytodegradation seems to be the most promising approach. It occurs mostly through an increase of the microbial activity in the plant rhizosphere, allowing the degradation of organic substances, a source of carbon for soil microbes. Despite a large amount of available data in the literature concerning laboratory and short term PAH phytodegradation experiments, no actual field application of such technique was previously carried out. In the present study, a soil from a former coking plant was used to evaluate the feasibility and the efficiency of PAH phytodegradation in the field during a three years trial and following a bioremediation treatment. Before the phytoremediation treatment, the soil was homogenized and split into six independent plots with no hydrological connections. On four of these plots, different types of common plant species were sowed: mixture of herbaceous species, short cut (P1), long cut (P2), ornamental plants (P3) and trees (P4). Natural vegetation was allowed to grow on the fifth plot (P5), and the last plot was weeded (P6). Each year, representative sampling of two soil horizons (0–50 and 50–100 cm) was carried out in each plot to characterize the evolution of PAHs concentration in soils and in soils solution obtained by lixiviation. Possible impact of the phytoremediation technique on ecosystems was evaluated using different eco- and genotoxicity tests both on the soil solid matrix and on the soil solution. For each soil horizon, comparable decrease of soil total PAHs concentrations were obtained for three plots, reaching a maximum value of 26% of the initial PAHs concentration. The decrease mostly concerned the 3 rings PAHs. The overall low decrease in PAHs content was linked to a drastic decrease in PAHs availability likely due to the bioremediation treatment. However, soil solutions concentration showed low values and no signficant toxicity was characterized. The mixture of the herbaceous species seemed to be the most promising plants to be used in such procedure.  相似文献   
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