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991.
O K Sharma 《Science (New York, N.Y.)》1978,202(4363):68-69
Actinomycin D and thioacetamide induced ovalbumin synthesis and increased serum progesterone concentrations in immature chicks. The increase in progesterone induced by the carcinogens actinomycin D and thioacetamide may account for the induction of ovalbumin synthesis. 相似文献
992.
An increase in the rate of mutation has been found in Drosophila melanogaster reared on a basic medium that was irradiated with a sterilizing dose (150,000 rads) of cobalt-60 gamma rays. In Muller-5 tests, sex-linked recessive lethals occurred only in the F(2) progenies of the male test flies obtained from breeding the parent flies on irradiated medium, while visible changes occurred in experimental cultures from both the control and irradiated media. The frequency of sex-linked recessive lethals was 0.35, 0.55, and 0.8 percent in three independent experiments. Visible changes were two to six times more frequent in the irradiated series than in the controls. 相似文献
993.
Diana Stuart 《Agriculture and Human Values》2008,25(2):177-181
I explore the role of nature in the agrifood system and how attempts to fit food production into a large-scale manufacturing
model has lead to widespread outbreaks of food borne illness. I illustrate how industrial processing of leafy greens is related
to the outbreak of E. coli 0157:H7 associated with spinach in the fall of 2006. I also use this example to show how industry attempts to create the
illusion of control while failing to address weaknesses in current processing systems. The leafy greens industry has focused
efforts on sterilizing the growing environment and adopting new technologies, while neglecting to change the concentrated
structure of processing systems. Repeated breakdowns in these systems illustrate a widening fault line between attempted and
failed control of nature in industrial food production.
相似文献
Diana StuartEmail: |
994.
Wei Feng Wenying Shen Li He Jianzhao Duan Binbin Guo Yingxue Li Chenyang Wang Tiancai Guo 《Precision Agriculture》2016,17(5):608-627
In this study, we investigated the possibility of using ground-based remote sensing technology to estimate powdery mildew disease severity in winter wheat. Using artificially inoculated fields, potted plants, and disease nursery tests, we measured the powdery mildew canopy spectra of varieties of wheat at different levels of incidence and growth stages to investigate the disease severity. The results showed that the powdery mildew sensitive bands were between 580 and 710 nm. The best two-band vegetation index that correlated with wheat powdery mildew between 400 and 1000 nm wavelength were the normalized spectrum 570–590 and 536–566 nm bands for the ratio index, and 568–592 and 528–570 nm for the normalized difference index. The coefficients of determination (R 2) for both were almost the same. The optimum dual-green vegetation index was constructed based on a calculation of the ratio and normalized difference between the normalized spectrum within the two green bands. The coefficients of determination (R 2) of DGSR (584, 550) (dual-green simple ratio) and DGND (584, 550) (dual-green normalized difference) were both 0.845. The inverse models of disease severity performed well in the test process at the canopy scale, and indicated that, compared with the traditional vegetation indices of Lwidth, mND705, ND (SDr, SDb), SIPI, and GNDVI, the novel dual-green indices greatly improved the remote sensing detection of wheat powdery mildew disease. Following these results, combined disease severity and canopy spectra were shown to be of enormous value when applied to the accurate monitoring, prevention, and control of crop diseases. 相似文献
995.
Most accounts of the effect of the global marketplace on deforestation in Africa, Asia, and Latin America emphasize the demand
for timber used in industrial processes and the conversion of tropical forests to pastures for beef cattle. In recent years,
numerous scholars and policymakers have suggested that developing a market for non-timber forest products (NTFPs) might slow
the pace of habitat destruction. Although increased demand for NTFPs rarely results in massive deforestation, the depletion
of the raw materials needed to make particular products is common.
Many rural households in the Mexican state of Oaxaca have prospered over the past three decades through the sale of brightly-painted,
whimsical wood carvings (alebrijes) to international tourists and the owners of ethnic arts shops in the United States, Canada, and Europe. This paper examines
a promising project aimed at providing Oaxacan alebrije-makers with a reliable, legal, and sustainable supply of wood. The
ecologists, artisans, merchants, and forest owners involved in the project face formidable obstacles. Gaining permission to
harvest wood from land belonging to Oaxacan communities requires the negotiation of a complex social, legal, economic, and
political landscape. Artisans’ decisions about where to obtain wood rest largely on price, quality, and reliability of the
supplier; they are willing to pay a premium for ecologically sustainable wood only if the additional cost can be passed on
to consumers. Nonetheless, a group of carvers has begun to buy sustainably harvested wood. This arrangement has economic advantages
for both the alebrije-makers and the owners of the forests where the wood is produced.
Michael
Chibnik is Professor of Anthropology at the University of Iowa. He has conducted fieldwork in Belize, Peru, Mexico, and in various
parts of the United States. His research interests include economic anthropology, artisans, work organization, agricultural
decision-making, and political ecology. He is the author of Crafting Tradition: The Making and Marketing of Oaxacan Wood Carvings
(University of Texas Press, 2003) and Risky Rivers: The Economics and Politics of Floodplain Farming in Amazonia (University of Arizona Press, 1994), and editor of Farm Work and Fieldwork: American Agriculture in Anthropological Perspective (Cornell University Press, 1987).
Dr. Silvia E. Purata is a Mexican ethnoecologist based in Xalapa, Veracruz. She is a member of People and Plants International, an organization
that works to integrate conservation and the use of natural resources. Purata has conducted research on the methods indigenous
peoples use to extract non-timber forest products (NTFPs) in tropical forests and the fate of such systems in varying socioeconomic
circumstances. She has also been working on the promotion of forest certification in the Selva Maya. 相似文献
996.
Food quality is an important issue on the global agenda, particularly in high- and middle-income economies, but of little concern in designing Mexico’s food policy. Food policy has focused on quantity and in the case of maize, on satisfying domestic demand by supporting large commercial agriculture and importing from abroad. However, and as argued in this paper, obtaining a food staple (maize-tortilla) of quality is also an important issue for rural households and contributes to motivating continued smallholder production. Based on case studies in the rural district of Atlacomulco, in the state of Mexico, as well as in two regions of the state of Chiapas, this paper analyzes the production and consumption strategies of rural households. We focus on goals of food security and quality and note differential trends among households of varying characteristics and local contexts. We find that the motivation of small-scale producers to grow maize should be supported by Mexico’s food policy. 相似文献
997.
Samuel Adjei-Nsiah Cees Leeuwis Ken E. Giller Thom W. Kuyper 《Agriculture and Human Values》2008,25(3):389-403
This study reports on action research efforts that were aimed at developing institutional arrangements beneficial for soil
fertility improvement. Three stages of action research are described and analyzed. We initially began by bringing stakeholders
together in a platform to engage in a collaborative design of new arrangements. However, this effort was stymied mainly because
conditions conducive for learning and negotiation were lacking. We then proceeded to support experimentation with alternative
arrangements initiated by individual landowners and migrant farmers. The implementation of these arrangements too ran into
difficulties due to intra-family dynamics and ambiguities regarding land tenure. Further investigations to find out how ambiguities
could be tackled revealed that the local actors themselves had taken initiatives towards developing institutional innovations
to reduce ambiguities. However, there is still considerable scope for further development of these self-organized innovations.
The article ends with a reflection on inter-disciplinary action research, where it is argued that making “mistakes” is an
inherent and necessary characteristic in action research that aims to address complex social issues.
相似文献
Samuel Adjei-NsiahEmail: |
998.
The economics of harvesting wheat based on input management zones in the northern wheatbelt of Western Australia was studied
using a simulated field of regular dimensions with varying zone sizes and layouts. Fertilizer application rates and crop yield
and quality data from field trials of input management were used to estimate the gross crop revenue and harvesting costs from
the different field layouts and zone combinations. As a general observation there was no consistency in the results; harvesting
by zone generated more gross income in some combinations of field layout and yield quantity scenarios, but not in others.
However, there were key factors in determining whether it was profitable to harvest by zone. These were prior knowledge of
the potential yield and quality characteristics of grain from each zone in a field, and the layout of zones within a field. 相似文献
999.
Alison Hope Alkon 《Agriculture and Human Values》2008,25(4):487-498
Advocates of environmental sustainability and social justice increasingly pursue their goals through the promotion of so-called
“green” products such as locally grown organic produce. While many scholars support this strategy, others criticize it harshly,
arguing that environmental degradation and social injustice are inherent results of capitalism and that positive social change
must be achieved through collective action. This study draws upon 18 months of ethnographic fieldwork at two farmers markets
located in demographically different parts of the San Francisco Bay Area to examine how market managers, vendors, and regular
customers negotiate tensions between their economic strategies and environmental sustainability and social justice goals.
Managers, vendors, and customers emphasize the ethical rather than financial motivations of their markets through comparisons
to capitalist, industrial agriculture and through attention to perceived economic sacrifices made by market vendors. They
also portray economic strategies as a pragmatic choice, pointing to failed efforts to achieve justice and sustainability through
policy change as well as difficulties funding and sustaining non-profit organizations. While market managers, vendors, and
customers deny any difficulties pursuing justice and sustainability through local economics, the need for vendors to sustain
their livelihoods does sometimes interfere with their social justice goals. This has consequences for the function of each
market.
Alison Hope Alkon is a Ph.D. candidate in the Department of Sociology at the University of California, Davis. Her research examines how efforts to create environmental protection and social justice operate in a market context. 相似文献
Alison Hope AlkonEmail: |
Alison Hope Alkon is a Ph.D. candidate in the Department of Sociology at the University of California, Davis. Her research examines how efforts to create environmental protection and social justice operate in a market context. 相似文献
1000.
Daniel R. Block Michael Thompson Jill Euken Toni Liquori Frank Fear Sherill Baldwin 《Agriculture and Human Values》2008,25(3):379-388
Engagement happens when academics and non-academics form partnerships to create mutual understanding, and then take action
together. An example is the “value web” work associated with W. K. Kellogg Foundation’s Food Systems Higher Education–Community
Partnership. Partners nationally work on local food systems development by building value webs. “Value chains,” a concept
with considerable currency in the private sector, involves creating non-hierarchical relationships among otherwise disparate
actors and entities to achieve collective common goals. The value web concept is extended herein by separating the values
of the web itself, such as the value of collaboration, from values “in” the web, such as credence values associated with a
product or service. By sharing and discussing case examples of work underway around the United States, the authors make a
case for employing the value webs concept to represent a strategy for local food systems development, specifically, and for
higher education–community partnerships, generally.
Daniel R. Block is an associate professor of geography and coordinator of the Frederick Blum Neighborhood Assistance Center at Chicago State University. His current research focuses on food access issues in urban environments, particularly in Chicago. Michael Thompson is an assistant professor at Oregon State University, and a Seafood and Fisheries specialist for Oregon Sea Grant Extension. Primary areas of research include fisheries management, seafood quality/handling, and seafood product development. Jill Euken is an industrial specialist for biobased products for Iowa State University Extension/CIRAS, and deputy director, ISU Bioeconomy Institute. She was part of the steering team for the Iowa Value Chain Partnership for Sustainable Agriculture and led the Bioeconomy Working Group. Toni Liquori is a nutritionist, teacher and food activist with a long time interest in the design, implementation, and evaluation of school-based intervention programs and coalition building for activism around food related issues, as well as teaching and training in public health. Frank Fear is senior associate dean, College of Agriculture and Natural Resources; and professor, in the Department of Community, Agriculture, Recreation and Resources Studies; and Senior Outreach Fellow at Michigan State University. He is lead author of Coming to Critical Engagement (University Press of America, 2006), an analysis of the engagement movement in higher education; and recently completed two terms as president of the Greater Lansing Food Bank. Sherill Baldwin is ecology director at Mercy Center at Madison, Connecticut, a spiritual retreat and conference center. She previously provided consulting services to CitySeed, Inc. in New Haven (CT) and to Frank Fear and the W. K. Kellogg Foundation for a community learning project related to sustainable food systems. She has an MS in Resource Development from Michigan State University and a BA in Solid Waste Management from the University of Massachusetts. 相似文献
Daniel R. BlockEmail: |
Daniel R. Block is an associate professor of geography and coordinator of the Frederick Blum Neighborhood Assistance Center at Chicago State University. His current research focuses on food access issues in urban environments, particularly in Chicago. Michael Thompson is an assistant professor at Oregon State University, and a Seafood and Fisheries specialist for Oregon Sea Grant Extension. Primary areas of research include fisheries management, seafood quality/handling, and seafood product development. Jill Euken is an industrial specialist for biobased products for Iowa State University Extension/CIRAS, and deputy director, ISU Bioeconomy Institute. She was part of the steering team for the Iowa Value Chain Partnership for Sustainable Agriculture and led the Bioeconomy Working Group. Toni Liquori is a nutritionist, teacher and food activist with a long time interest in the design, implementation, and evaluation of school-based intervention programs and coalition building for activism around food related issues, as well as teaching and training in public health. Frank Fear is senior associate dean, College of Agriculture and Natural Resources; and professor, in the Department of Community, Agriculture, Recreation and Resources Studies; and Senior Outreach Fellow at Michigan State University. He is lead author of Coming to Critical Engagement (University Press of America, 2006), an analysis of the engagement movement in higher education; and recently completed two terms as president of the Greater Lansing Food Bank. Sherill Baldwin is ecology director at Mercy Center at Madison, Connecticut, a spiritual retreat and conference center. She previously provided consulting services to CitySeed, Inc. in New Haven (CT) and to Frank Fear and the W. K. Kellogg Foundation for a community learning project related to sustainable food systems. She has an MS in Resource Development from Michigan State University and a BA in Solid Waste Management from the University of Massachusetts. 相似文献