991 resultados para Moore, Pliny.


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The findings from a study measuring consumer acceptance of genetically modified (GM) foods are presented. The empirical data were collected in an experimental market, an approach used extensively in experimental economics for measuring the monetary value of goods. The approach has several advantages over standard approaches used in sensory and marketing research (e.g., surveys and focus groups) because of its non-hypothetical nature and the realism introduced by using real goods, real money, and market discipline. In each of three US locations, we elicited the monetary compensation consumers required to consume a GM food. Providing positive information about the benefits of GM food production, in some cases, reduced the level of monetary compensation demanded to consume the GM food. (C) 2004 Elsevier Ltd. All rights reserved.

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Non-hypothetical valuations obtained from experimental auctions in three United States and two European locations were used to calculate welfare effects of introducing and labeling of genetically modified food. Under certain assumptions, we find that introduction of genetically modified food has been welfare enhancing, on average, for United States consumers but not so for Europeans and while mandatory labeling has been beneficial for European consumers, such a policy would be detrimental in the United States. (c) 2005 Elsevier B.V. All rights reserved.

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This study investigates the effect of information about potential benefits of biotechnology on consumer acceptance of genetically modified (GM) foods. Consumer willingness to accept compensation to consume a GM food was elicited using an incentive compatible auction mechanism in three US states (California, Florida, and Texas) and in two European countries (England and France). Results indicate that information on environmental benefits, health benefits and benefits to the third world significantly decreased the amount of money consumers demanded to consume GM food; however, the effect of information varied by type of information and location. Consistent with prior research, we find that initial attitudes toward biotechnology have a significant effect on how individuals responded to new information.

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The United States (US) exports more than US$6 billion in agricultural commodities to the European Union (EU) each year, but one issue carries the potential to diminish this trade: use of biotechnology in food production. The EU has adopted more stringent policies towards biotechnology than the US. Understanding differences in European and American policies towards genetically modified (GM) foods requires a greater understanding of consumers' attitudes and preferences. This paper reports results from the first large-scale, cross-Atlantic study to analyse consumer demand for genetically modified food in a non-hypothetical market environment. We strongly reject the frequent if convenient assumption in trade theory that consumer preferences are identical across countries: the median level of compensation demanded by English and French consumers to consume a GM food is found to be more than twice that in any of the US locations. Results have important implications for trade theory, which typically focusses on differences in specialization, comparative advantage and factor endowments across countries, and for on-going trade disputes at the World Trade Organization.

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The rate and scale of human-driven changes can exert profound impacts on ecosystems, the species that make them up and the services they provide that sustain humanity. Given the speed at which these changes are occurring, one of society's major challenges is to coexist within ecosystems and to manage ecosystem services in a sustainable way. The effect of possible scenarios of global change on ecosystem services can be explored using ecosystem models. Such models should adequately represent ecosystem processes above and below the soil surface (aboveground and belowground) and the interactions between them. We explore possibilities to include such interactions into ecosystem models at scales that range from global to local. At the regional to global scale we suggest to expand the plant functional type concept (aggregating plants into groups according to their physiological attributes) to include functional types of aboveground-belowground interactions. At the scale of discrete plant communities, process-based and organism-oriented models could be combined into "hybrid approaches" that include organism-oriented mechanistic representation of a limited number of trophic interactions in an otherwise process - oriented approach. Under global change the density and activity of organisms determining the processes may change non-linearly and therefore explicit knowledge of the organisms and their responses should ideally be included. At the individual plant scale a common organism-based conceptual model of aboveground-belowground interactions has emerged. This conceptual model facilitates the formulation of research questions to guide experiments aiming to identify patterns that are common within, but differ between, ecosystem types and biomes. Such experiments inform modelling approaches at larger scales. Future ecosystem models should better include this evolving knowledge of common patterns of aboveground-belowground interactions. Improved ecosystem models are necessary toots to reduce the uncertainty in the information that assists us in the sustainable management of our environment in a changing world. (C) 2004 Elsevier GmbH. All rights reserved.

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The stated benefits and perceived risks of genetic modification (GM) cover very diverse issues, such as food safety, world food security, and the environment, that may differentially affect consumer acceptance. In this research, we hypothesize that consumers perceive up to eight dimensions: risks to business (farmers, agribusiness, etc.), benefits to business, risks and benefits to the environment, risks and benefits to the developing world, and risks and benefits to self and family. Moral concerns are also recognized. Using data collected in 2002 in the United States, France, and the UK, we investigate these different dimensions. Second, we analyze the extent to which the dimensions of risk-benefit perceptions can be explained by general attitudes widely used to explain food purchase behavior (such as general attitude to the environment, to technology, etc.), as well as by perceived knowledge of GM, level of education, and trust in various sources of information. In all locations, the majority of consumers only perceive a medium level of risk from GM products. Attitude to technology is the most important attitude variable—those with a positive attitude to technology in general also have a positive attitude to GM technology. More Americans than Europeans fall into this category. Those who trust government and the food industry tend to think GM technology is less risky, whereas those who trust activists believe the opposite. Americans are more trusting of the former, Europeans of the latter. Level of education is positively associated with benefit perceptions and negatively associated with moral concerns. Location continues to play a limited independent role in explaining perceptions even after these factors have been taken into account.

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This paper investigates Willingness to Accept (WTA) Genetic Modification (GM) foods based on experimental auctions carried out in the USA, UK and France. It explores perceptions of risk and benefits, moral concerns and their antecedents, attitudes to the environment and technology and trust in various sources using Structural Equation Modelling (SEM). Trust in information provided by industry proved to be the most important determinant of risk/benefit perceptions and WTA followed by general attitudes to the environment and technology. Education and age are also enhance perceived benefits and lower perceived risks of GM. Perception of risk/benefit and moral concerns all have significant effects on consumers' WTA but the perceived benefits are most important. The research suggests that trust-building by industry would be the most effective in enhancing GM acceptance.

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Despite theoretical predictions, dishonest signalling has rarely been observed in aggressive interactions. We present evidence of such signalling in the nonpollinating. g wasp Philotrypesis sp. A ex Ficus rubiginosa. First, morphometric data indicated that an alternative 'atypical' male morph (17.8% of individuals) exists that tends to be larger in body size and has longer mandibles for a given body size than other 'typical' males. Second, behavioural observations suggested that males use mandible gape width (which depends on mandible length) as a cue to assess opponents before fights and retreat without escalating if they are unlikely to win, and, probably because their greater mandible gape width causes more opponents to retreat without escalating, that atypical males engaged in fewer fights than typical males for a given body size but had higher mating success. Third, atypical males were less likely to win fights than typical males of similar mandible length relative to opponents. In addition, we found that atypical males incur more injuries (greater receiver-dependent signal costs) than typical males of similar body size relative to rivals. We discuss the implications of our findings for future work on dishonest signalling. (C) 2009 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.

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DNA microarrays can be used to measure environmental stress responses. If they are to be predictive of environmental impact, we need to determine if altered gene expression translates into negative impacts on individuals and populations. A large cDNA microarray (14000 spots) was created to measure molecular stress responses to cadmium in Daphnia magna,the most widely used aquatic indicator species, and relate responses to population growth rate (pgr). We used the array to detect differences in the transcription of genes in juvenile D. magna (24 h old) after 24 h exposure to a control and three cadmium concentrations (6, 20, and 37 mu g Cd2+ L-1). Stress responses at the population level were estimated following a further 8 days exposure. Pgr was approximately linear negative with increasing cadmium concentration over this range. The microarray profile of gene expression in response to acute cadmium exposure begins to provide an overview of the molecular responses of D. magna, especially in relation to growth and development. Of the responding genes, 29% were involved with metabolism including carbohydrate, fat and peptide metabolism, and energy production, 31% were involved with transcription/translation, while 40% of responding genes were associated with cellular processes like growth and moulting, ion transport, and general stress responses (which included oxidative stress). Our production and application of a large Daphnia magna microarray has shown that measured gene responses can be logically linked to the impact of a toxicant such as cadmium on somatic growth and development, and consequently pgr.

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Although theory exists concerning the types of strategies that should be used in contests over resources, empirical work explicitly testing its predictions is relatively rare. We investigated male fighting strategies in two nonpollinating. g wasp species associated with Ficus rubiginosa figs. In Sycoscapter sp. A, males did not assess each other before or during fights over mating opportunities. Instead,fights continued until the loser reached an energetic cost threshold that was positively correlated with its body size (fighting ability) and retreated. In Philotrypesis sp. B, pre fight assessment was indicated, with males attacking competitively inferior rivals to remove them from the competitor pool ( they then continued to do so until they reached a cost threshold that was again positively correlated with body size). Using data on species ecology, we discuss our findings with respect to theory on when different fighting strategies should evolve. We argue that the type of strategy used by a. g wasp species is determined by its relative benefits in terms of inclusive fitness. (c) 2008 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.

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Current research into indirect phytopathogen–herbivore interactions (i.e., interactions mediated by the host plant) is carried out in two largely independent directions: ecological/mechanistic and molecular. We investigate the origin of these approaches and their strengths and weaknesses. Ecological studies have determined the effect of herbivores and phytopathogens on their host plants and are often correlative: the need for long-term manipulative experiments is pressing. Molecular/cellular studies have concentrated on the role of signaling pathways for systemic induced resistance, mainly involving salicylic acid and jasmonic acid, and more recently the cross-talk between these pathways. This cross-talk demonstrates how interactions between signaling mechanisms and phytohormones could mediate plant–herbivore–pathogen interactions. A bridge between these approaches may be provided by field studies using chemical induction of defense, or investigating whole-organism mechanisms of interactions among the three species. To determine the role of phytohormones in induced resistance in the field, researchers must combine ecological and molecular methods. We discuss how these methods can be integrated and present the concept of “kaleidoscopic defense.” Our recent molecular-level investigations of interactions between the herbivore Gastrophysa viridula and the rust fungus Uromyces rumicis on Rumex obtusifolius, which were well studied at the mechanistic and ecological levels, illustrate the difficulty in combining these different approaches. We suggest that the choice of the right study system (possibly wild relatives of model species) is important, and that molecular studies must consider the environmental conditions under which experiments are performed. The generalization of molecular predictions to ecologically realistic settings will be facilitated by “middle-ground studies” concentrating on the outcomes of the interactions.

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The purpose of this paper is to provide an insight into the growth stage of facilities management (FM) in the South East Asia region. A questionnaire study of local and international firms operating in South East Asia was used. South East Asia needs to open up to change, particularly with respect to parity in issues of global competition in FM standards. This study is based on a limited sample size using a self-reporting methodology. Further research is needed to further investigate the findings. This paper addresses a unique insight into the contrasting approach to FM in the South East Asia region.

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This report summarises a workshop convened by the UK Food Standards Agency (FSA) on 11 September 2006 to review the results of three FSA-funded studies and other recent research on effects of the dietary n-6:n-3 fatty acid ratio on cardiovascular health. The objective of this workshop was to reach a clear conclusion on whether or not it was worth funding any further research in this area. On the basis of this review of the experimental evidence and on theoretical grounds, it was concluded that the n-6:n-3 fatty acid ratio is not a useful concept and that it distracts attention away from increasing absolute intakes of long-chain n-3 fatty acids which have been shown to have beneficial effects on cardiovascular health. Other markers of fatty acid intake, that more closely relate to physiological function, may be more useful.

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The metabolism of chlorogenic acid., naringin, and rutin, representative members of three common families of dietary polyphenols, the hydroxycinnamates, the flavanones, and the flavonols, respectively, was studied in an in vitro mixed culture model of the human colonic microflora. Time- and concentration-dependent degradation of all three compounds was observed, which was associated with the following metabolic events after cleavage of the ester or glycosidic bond: reduction of the aliphatic double bond of the resulting hydroxycinnamate caffeic acid residue; dehydroxylation and ring fission of the heterocyclic C-ring of the resulting deglycosylated flavanone, naringenin, and of the deglycosylated flavonol, quercetin (which differed depending on the substitution). The metabolic events, their sequences, and major phenolic end products, as identified by GC-MS or LC-MS/MS, were elucidated from the structural characteristics of the investigated compounds. The major phenolic end products identified were 3-D-hydroxyphenyl)propionic acid for chlorogenic acid, 3-(4-hydroxyphenyl)-propionic acid and 3-phenylpropionic acid for naringin, and 3-hydroxyphenylacetic acid and 3-(3-hydroxyphenyl)-propionic acid for rutin. The degree of degradation of the compounds studied was significantly influenced by the substrate concentration as well as individual variations in the composition of the fecal flora. The results support extensive metabolism of dietary polyphenols in the colon, depending on substrate concentration and residence time, with resultant formation of simple phenolics, which can be considered biomarkers of colonic metabolism if subsequently absorbed. It is also apparent that a relatively small number of phenolic degradation products are formed in the colon from the diverse group of natural polyphenols. (C) 2003 Elsevier Inc. All rights reserved.