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排序方式: 共有10000条查询结果,搜索用时 31 毫秒
981.
Mi-Young Kang Catherine W. Rico Sang-Chul Lee 《Journal of Crop Science and Biotechnology》2011,14(2):111-118
The physicochemical properties of pigmented (Midorimochi, Jeokjinjubyeo, and Heukmichalbyeo) and non-pigmented (Hwayoungbyeo)
rice varieties were investigated. Starch from non-pigmented rice consisted mainly of large polyhedral granules that were more
loosely packed than those of the non-pigmented sample. Pigmented rice showed higher linoleic acid content (36–40%) and hydrolysis
rate (63–79%) but lower oleic acid content (35–39%), blue value (0.05–0.17), and viscosity values than the non-pigmented one.
Significantly higher mineral content, blue value, and pasting and viscosity values were observed in the Jeokjinjubyeo sample
compared to those of the other pigmented rice samples. The Midorimochi variety, on the other hand, exhibited the highest total
amino acid (816.82 ng mg−1) and sugar (0.15–3.35 μg g−1) contents and the lowest pasting and viscosity values. No substantial difference in the X-ray diffraction pattern was observed
among the samples. Results of this study could serve as baseline information for the quality evaluation of three pigmented
rice cultivars and provide a better understanding of their potential uses and food industry applications. 相似文献
982.
Canopy cover (CC) is a good predictor variable for plant growth parameters such as leaf area index and aboveground biomass.
A nondestructive, low-cost, and convenient method is presented for estimating CC using digital camera image analysis. CC was
estimated by the ratio of plant pixels to total pixels of digital camera image of rice field. To determine the criteria for
segmenting the rice plant from variable soil background, three mosaic images for rice plant, flooded/bare soil, and algae-infested
background were prepared from digital camera images that were taken in various field conditions. An image analysis program
was developed in Visual Basic to extract red, green, and blue (RGB) features from the mosaic images, calculate RGB-based color
indices, and compute the minimum segmentation error for separating rice plant from background. When judged by the segmentation
error, modified excessive green index (MEGI) showed the highest potential for segmenting rice plant from flooded/bare soil
background, followed by normalized green (g) and excessive green index (EGI). At the threshold MEGI value of 0.03, the segmentation
error was the lowest as 0.13%. Any single index considered was not satisfactory in segmenting rice plant from algae-infested
background. However, a discriminant function of 1.2553EGI + 0.01735G − 0.01474B was successful in segmenting rice plant from
flooded/bare soil and algaeinfested background with segmentation errors of 0.34 and 1.17%, respectively. CC for four rice
varieties from tillering to booting stage was estimated based on the threshold value of MEGI and discriminant function and
also manually using commercial software. Both estimates of CC showed good relationship of r2 = 0.94, suggesting that a digital camera could be used efficiently for measuring the CC of rice field. 相似文献
983.
Hitoshi Fujiie Atsushi Maruyama Masako Fujiie Michiko Takagaki Douglas J. Merrey Masao Kikuchi 《Irrigation and Drainage Systems》2011,25(1):39-60
It is well-known that major irrigation projects have a strong scale economy, handicapping irrigation development in sub-Saharan
Africa (SSA) because of the difficulty in formulating large-scale projects. Using project-level investment cost and performance
data of major and minor irrigation projects, this paper examines the causes of the economy of scale phenomenon. We find that
strong scale economy exists not only for major but also for minor projects, i.e., small- and micro-scale, projects. This is
largely because of the existence of indivisible overhead costs such as high-opportunity-cost human resources for planning,
designing and engineering management and supervision. We also find that large differences between major and minor projects
in the absolute level of overhead as well as construction costs creates a strong scale diseconomy and results in better performance
of minor projects. The advantage of minor projects holds even when their higher risk associated with the water source is taken
into consideration. We argue that there is an urgent need to promote irrigation development in SSA through developing minor
projects, and to reduce the heavy burden of overhead costs by developing the capacity of human resources at the national,
local and farmer levels in the fields of irrigation engineering, irrigation agronomy, institutional development, and micro
water management technologies. 相似文献
984.
K. Palanisami Ruth Meinzen-Dick Mark Giordano Barbara Van Koppen C. R. Ranganathan 《Irrigation and Drainage Systems》2011,25(3):121-134
Irrigation tanks in India are common property resources. Tanks provide not only for irrigation, but also forestry, fishing,
domestic water supply, livestock, and other uses. Using empirical results from a study of tank performance from 80 tanks in
Tamil Nadu, South India in two time period: 1996-97 and 2009-10, this paper evaluates tank irrigation system performance in
terms of economic output and revenue generation forirrigation and other uses. The results indicate that irrigation and other
productive uses put together raised the total value of output at tank level by 12 % in 1996-97 and just 6 % in 2009-10. This
may suggest that tank multiple use values are small and getting smaller, and therefore not worth consideration. However, it
was also found that, while declining in absolute terms, non-irrigation uses provided the majority of tax revenues and still
more than cover government's operation and maintenance expenditure (O&M) budget. This finding provides another reason to consider
multiple use values and their linkage with overall system viability. 相似文献
985.
This paper introduces a combined modelling approach using a simple water budget model (THC-model) and a 3D reservoir sedimentation
model (MOHID Water) to adapt reservoir operation and visualise their effects on the sediment deposition. By this, an effective
combined sediment-water management can be identified under semi-arid conditions for dry, median and wet years. Results are
presented for the reservoirs of the Tuyamuyun Hydro-Complex (THC), which is located in the lower Amu Darya River. The determination
of the actual and usable reservoir storage volume shows that siltation will significantly adversely affect the ability of
the in-stream Channel Reservoir to regulate seasonal demand for both irrigation and municipal water supply. However, modelling
scenarios results confirm the effectiveness of adapted operation rules for the THC reservoirs and show that the operation
of large dams could be modified according to a combined sediment-water management. The experience gained during this study
emphasizes the fact that the concept of a combined reservoir management of sediments as well as water can be an efficient
measure to improve the sustainable long-term use of reservoirs and to contribute towards a safe water supply in water crisis
regions. 相似文献
986.
987.
CENH3 is a centromere-specific histone H3 variant essential for kinetochore assembly. Despite its central role in centromere function, there has been no conclusive evidence supporting CENH3 as sufficient to determine centromere identity. To address this question, we artificially targeted Drosophila CENH3 (CENP-A/CID) as a CID-GFP-LacI fusion protein to stably integrated lac operator (lacO) arrays. This ectopic CID focus assembles a functional kinetochore and directs incorporation of CID molecules without the LacI-anchor, providing evidence for the self-propagation of the epigenetic mark. CID-GFP-LacI-bound extrachromosomal lacO plasmids can assemble kinetochore proteins and bind microtubules, resulting in their stable transmission for several cell generations even after eliminating CID-GFP-LacI. We conclude that CID is both necessary and sufficient to serve as an epigenetic centromere mark and nucleate heritable centromere function. 相似文献
988.
Colin PL 《Science (New York, N.Y.)》2003,300(5626):1657-9; author reply 1657-9
989.
Linder P 《Science (New York, N.Y.)》2004,304(5671):694-695
990.
Anthony Winson 《Agriculture and Human Values》2008,25(4):499-511
To understand the phenomenon of the rapidly increasing prevalence of overweight and obese children and youth, it is especially
important to examine the school food environment, the role of structural factors in shaping this environment, and the resulting
nutrition and health outcomes. The paper examines research on school food environments in the US and Canada. It notes evidence
of widespread availability of poor nutrition products in both environments and delineates reasons for the situation, and examines
initiatives presently being undertaken in a number of jurisdictions in both countries to encourage healthy eating in schools.
Empirical data are presented from a pilot study of high schools in the Canadian province of Ontario. The study documents the
extent of student purchasing of nutrient-poor foods and beverages, and the structural factors internal and external to the
school that appear responsible for the availability of such products in food environments in this critical institutional sphere.
The paper also examines positive local initiatives in high schools that seek to encourage healthy eating in schools.
Anthony Winson PhD is a professor in the department of sociology and anthropology at the University of Guelph. He has written on agriculture, food and rural development, and restructuring issues related to Canada and the Third World for more than 20 years. Among his books are The Intimate Commodity: Food and the Development of the Agro-Industrial Complex in Canada (Garamond 1993) and, more recently, Contingent Work, Disrupted Lives (University of Toronto 2002, with Belinda Leach) which examines economic restructuring, the changing world of work, and the factors underlying sustainability in small manufacturing-dependent rural communities in several regions of Ontario. This book won the John Porter Book Prize of the Canadian Sociology and Anthropology Association for 2003. Dr. Winson’s current work is focused on the analysis of factors shaping the contemporary Canadian food environment and their role in producing what has been termed the “epidemic of obesity.” Particular attention is being paid to supermarkets and schools as part of broader-ranging research on the political economic context of the food environment. 相似文献
Anthony WinsonEmail: |
Anthony Winson PhD is a professor in the department of sociology and anthropology at the University of Guelph. He has written on agriculture, food and rural development, and restructuring issues related to Canada and the Third World for more than 20 years. Among his books are The Intimate Commodity: Food and the Development of the Agro-Industrial Complex in Canada (Garamond 1993) and, more recently, Contingent Work, Disrupted Lives (University of Toronto 2002, with Belinda Leach) which examines economic restructuring, the changing world of work, and the factors underlying sustainability in small manufacturing-dependent rural communities in several regions of Ontario. This book won the John Porter Book Prize of the Canadian Sociology and Anthropology Association for 2003. Dr. Winson’s current work is focused on the analysis of factors shaping the contemporary Canadian food environment and their role in producing what has been termed the “epidemic of obesity.” Particular attention is being paid to supermarkets and schools as part of broader-ranging research on the political economic context of the food environment. 相似文献