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681.
To combat high rates of malnutrition in sub‐Saharan Africa, the UN Millennium Project has called for increased emphasis on technologies that explicitly link agricultural and nutritional components. While there is a large literature on the factors that influence household decisions to adopt new agricultural technologies with economic or environmental benefits, less is known about the factors that determine the uptake and continued use of agricultural technologies promoted exclusively for their health benefits. Using data from a 2004 survey in the Tamberma region of Togo and Benin, we identify factors that influence the adoption and disadoption of soybeans — a crop being promoted throughout West Africa for its high protein content. Similar to the literature on adoption of other sustainable agriculture technologies, we find that household preferences, resource endowments, and risk and uncertainty affect household decisions about soybeans. However, by analyzing decisions about initial uptake and continued cultivation separately, we uncover the importance of intrahousehold dynamics and experience with the soybean crop. To successfully address malnutrition through new agricultural technologies, researchers and rural extension agents should take a disaggregated view of technology adoption, seeking to identify and tailor their outreach to the different factors important at different stages of the dissemination process. 相似文献
682.
Roy Brouwer 《Journal of Environmental Planning and Management》2008,51(5):597-614
This paper examines the issue of disproportionate costs of Water Framework Directive (WFD) implementation using public surveys as a means to inform policy and decision making. Public taxpayers are asked their opinion regarding the implementation of the WFD and its costs. Taxpayers are expected to bear a large share of the cost of WFD implementation, be it through national taxation, local water pollution charges or higher market prices for water related goods and services. The paper's main objective is to illustrate the role of stated preference research to elicit public opinions and perceptions towards socially acceptable levels of water quality and public willingness to pay (WTP) for the expected environmental benefits of the WFD. Stated preference research can be used as a way to assess the concept of disproportionate costs to those who are expected to bear a large share of the costs of WFD implementation, and at the same time address the issue of public participation in the WFD. The survey results are used as a public consultation tool to inform policy and decision makers about public willingness and ability to pay for the implementation of the WFD. This measure can be used as one of the benchmarks to define disproportionate costs in a cost-benefit context. 相似文献
683.
Braulio Jiménez-Vélez Yasmín Detrés Roy A. Armstrong Adriana Gioda 《Atmospheric environment (Oxford, England : 1994)》2009,43(16):2659-2664
An Aerosol and Oceanographic Science Expedition (AEROSE) on the NOAA Ship Ronald H. Brown collected PM2.5 particles from a Saharan dust storm in March 2004. High levels of PM2.5 (120 μg m?3) were measured during this Saharan storm over the Atlantic Ocean. The particles were characterized for trace element content, with Al and Fe the most abundant metals. These metals were detected in high concentrations during the Saharan event and exhibited good correlations with PM2.5, suggesting its soil origin. Other elements (Pb, Ni, Cd) did not correlate with Al and Fe, indicating their anthropogenic origin. Enrichment factor calculation conducted on these trace elements support our findings. Trace element analyses performed on particulate matter from a reference site on land in Puerto Rico (Fajardo), demonstrated similar results to those obtained in the AEROSE expedition, where high concentrations of PM2.5 and Fe were present concomitantly with Saharan events at this station. 相似文献
684.
685.
Rui de Abrantes João Vicente de Assunção Célia Regina Pesquero Roy Edward Bruns Raimundo Paiva Nóbrega 《Atmospheric environment (Oxford, England : 1994)》2009,43(3):648-654
The exhaust emission of the polycyclic aromatic hydrocarbons (PAHs) considered toxic to human health were investigated on two spark ignition light duty vehicles, one being gasohol (Gasohol, in Brazil, is the generic denomination for mixtures of pure gasoline plus 20–25% of anhydrous ethyl alcohol fuel (AEAF).)-fuelled and the other a flexible-fuel vehicle fuelled with hydrated ethanol. The influence of fuel type and quality, aged lubricant oil type and use of fuel additives on the formation of these compounds was tested using standardized tests identical to US FTP-75 cycle. PAH sampling and chemical analysis followed the basic recommendations of method TO-13 (United States. Environmental Protection Agency, 1999. Compendium Method TO-13A – Determination of polycyclic Aromatic hydrocarbons (PAH) in Ambient Air Using Gas Chromatography/Mass Spectrometry (CG/MS). Center for environmental research information, Cincinnati, p. 78), with the necessary modification for this particular application.Results showed that the total PAH emission factor varied from 41.9 μg km?1 to 612 μg km?1 in the gasohol vehicle, and from 11.7 μg km?1 to 27.4 μg km?1 in the ethanol-fuelled vehicle, a significant difference in favor of the ethanol vehicle. Generally, emission of light molecular weight PAHs was predominant, while high molecular weights PAHs were not detected. In terms of benzo(a)pyrene toxicity equivalence, emission factors varied from 0.00984 μg TEQ km?1 to 4.61 μg TEQ km?1 for the gasohol vehicle and from 0.0117 μg TEQ km?1 to 0.0218 μg TEQ km?1 in the ethanol vehicle.For the gasohol vehicle, results showed that the use of fuel additive causes a significant increase in the emission of naphthalene and phenanthrene at a confidence level of 90% or higher; the use of rubber solvent on gasohol showed a reduction in the emission of naphthalene and phenanthrene at the same confidence level; the use of synthetic oil instead of mineral oil also contributed significantly to a decrease in the emission of naphthalene and fluorene. In relation to the ethanol vehicle, the same factors were tested and showed no statistically significant influence on PAH emission. 相似文献
686.
Attitudes have been a commonly used psychological measure of program effectiveness in conservation social science research. The major limitation of this approach is that attitudes do not always translate into behavior and therefore may not provide an accurate assessment of program success. Given that achieving conservation goals generally relies on understanding and changing human behavior, we argue for the need to assess behavior rather than attitudes as an indicator of conservation outcomes. Psychological theory shows that attitudes and behavior are distinct, but related, concepts. Measuring conservation behaviors involves identifying the target behavior or behaviors and the optimal time to measure and then selecting the most appropriate method of measurement (i.e., direct observation, objective indicators, self-reported behavior, and behavioral intentions) that considers the strengths and weaknesses of each approach. We call for conservation programs to focus on influencing behavior rather than attitudes alone and encourage conservation practitioners and researchers to collect high-quality behavioral data to more effectively inform policy and programs. 相似文献
687.
Targeted gene flow is an emerging conservation strategy. It involves translocating individuals with favorable genes to areas where they will have a conservation benefit. The applications for targeted gene flow are wide-ranging but include preadapting native species to the arrival of invasive species. The endangered carnivorous marsupial, the northern quoll (Dasyurus hallucatus), has declined rapidly since the introduction of the cane toad (Rhinella marina), which fatally poisons quolls that attack them. There are, however, a few remaining toad-invaded quoll populations in which the quolls survive because they know not to eat cane toads. It is this toad-smart behavior we hope to promote through targeted gene flow. For targeted gene flow to be feasible, however, toad-smart behavior must have a genetic basis. To assess this, we used a common garden experiment, comparing offspring from toad-exposed and toad-naïve parents raised in identical environments, to determine whether toad-smart behavior is heritable. Offspring from toad-exposed populations were substantially less likely to eat toads than those with toad-naïve parents. Hybrid offspring showed similar responses to quolls with 2 toad-exposed parents, indicating the trait may be dominant. Together, these results suggest a heritable trait and rapid adaptive response in a small number of toad-exposed populations. Although questions remain about outbreeding depression, our results are encouraging for targeted gene flow. It should be possible to introduce toad-smart behavior into soon to be affected quoll populations. 相似文献
688.
ABSTRACT In forest frontiers, smallholder agrarian livelihoods remain uneasily juxtaposed with conservation interests. Agricultural intensification is often considered a viable means of reconciling competing environmental and livelihood objectives given its potential to concentrate production on less land. However, intensification may have unintended consequences, including loss of resilient agricultural systems. The risks of smallholder agricultural intensification warrant a better understanding of its drivers. This study uses the case of Calakmul, Mexico, to examine the critical role of the state in intensification processes. Drawing on household surveys and key-informant interviews, it traces the linkages between state institutions and local farming practices. Statistical and qualitative analyses reveal how intensification is both incentivized and imposed by prevailing policies, the former via subsidies and the latter via regulations against field rotations. The outcome – increased external inputs and longer cultivation periods between fallows – may undermine the sustainability of smallholders’ agroecosystems, an undesirable consequence amid limited livelihood alternatives. 相似文献
689.
Naomi L. Indigo Chris J. Jolly Ella Kelly James Smith Jonathan K. Webb Ben L. Phillips 《Conservation biology》2021,35(4):1245-1255
Cultural adaptation is one means by which conservationists may help populations adapt to threats. A learned behavior may protect an individual from a threat, and the behavior can be transmitted horizontally (within generations) and vertically (between generations), rapidly conferring population-level protection. Although possible in theory, it remains unclear whether such manipulations work in a conservation setting; what conditions are required for them to work; and how they might affect the evolutionary process. We examined models in which a population can adapt through both genetic and cultural mechanisms. Our work was motivated by the invasion of highly toxic cane toads (Rhinella marina) across northern Australia and the resultant declines of endangered northern quolls (Dasyurus hallucatus), which attack and are fatally poisoned by the toxic toads. We examined whether a novel management strategy in which wild quolls are trained to avoid toads can reduce extinction probability. We used a simulation model tailored to quoll life history. Within simulations, individuals were trained and a continuous evolving trait determined innate tendency to attack toads. We applied this model in a population viability setting. The strategy reduced extinction probability only when heritability of innate aversion was low (<20%) and when trained mothers trained >70% of their young to avoid toads. When these conditions were met, genetic adaptation was slower, but rapid cultural adaptation kept the population extant while genetic adaptation was completed. To gain insight into the evolutionary dynamics (in which we saw a transitory peak in cultural adaptation over time), we also developed a simple analytical model of evolutionary dynamics. This model showed that the strength of natural selection declined as the cultural transmission rate increased and that adaptation proceeded only when the rate of cultural transmission was below a critical value determined by the relative levels of protection conferred by genetic versus cultural mechanisms. Together, our models showed that cultural adaptation can play a powerful role in preventing extinction, but that rates of cultural transmission need to be high for this to occur. 相似文献
690.
Kamaraj Jesuraja Sekar Selvam Roy Priyadarsi D. Senapathi Venkatramanan Chung Sang Yong Perumal Muthukumar Nath Akhila V. 《Environmental science and pollution research international》2021,28(23):29056-29074
Environmental Science and Pollution Research - We assessed groundwater pollution index (GPI) and groundwater quality of coastal aquifers from Tiruchendur in South India for drinking and irrigation... 相似文献