2,054 research outputs found
The Agricultural Research System of the Philippines: A Reconnaissance Report
Research and Development/Tech Change/Emerging Technologies,
Total factor productividty growth in agriculture: the role of technological capital.
In this chapter we compute measures of total factor productivity (TFP) growth for developing countries and then contrast TFP growth with technological capital indexes. In developing these indexes, we incorporate schooling capital to yield two new indexes: Invention-Innovation Capital and Technology Mastery. We find that TFP performance is strongly related to technological capital and that technological capital is required for TFP and cost reduction growth. Investments in technological capital require long-term (20- to 40-year) investments, which are typically made by governments and aid agencies and are the only viable escape route from mass poverty
Methods for Agricultural Policy Analysis: An Overview
This article summarizes the articles that have been presented at the Workshop on Methods for Agricultural Policy Analysis held at UP Los Baños on August 13-14, 1985. It has four parts: the farm production/productivity change, the food consumption, the rural/ agricultural households in imperfect market settings and the methodologies for combining partial and general equilibrium framework.economic/development modelling, computable general equilibrium (CGE), agriculture sector
Heliospheric Transport of Neutron-Decay Protons
We report on new simulations of the transport of energetic protons
originating from the decay of energetic neutrons produced in solar flares.
Because the neutrons are fast-moving but insensitive to the solar wind magnetic
field, the decay protons are produced over a wide region of space, and they
should be detectable by current instruments over a broad range of longitudes
for many hours after a sufficiently large gamma-ray flare. Spacecraft closer to
the Sun are expected to see orders-of magnitude higher intensities than those
at the Earth-Sun distance. The current solar cycle should present an excellent
opportunity to observe neutron-decay protons with multiple spacecraft over
different heliographic longitudes and distances from the Sun.Comment: 12 pages, 4 figures, to be published in special issue of Solar
Physic
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Advanced Hydrogen Transport Membranes for Vision 21 Fossil Fuel Plants
The objective of this project was to develop an environmentally benign, inexpensive, and efficient method for separating hydrogen from gas mixtures produced during industrial processes, such as coal gasification. A family of hydrogen separation membranes was developed including single phase mixed conducting ceramics, ceramic/ceramic composites, cermet membranes, cermet membranes containing a hydrogen permeable metal, and intermediate temperature composite layered membranes. Each membrane type had different operating parameters, advantages, and disadvantages that were documented over the course of the project. Research on these membranes progressed from ceramics to cermets to intermediate temperature composite layered membranes. During this progression performance was increased from 0.01 mL x min{sup -1} x cm{sup -2} up to 423 mL x min{sup -1} x cm{sup -2}. Eltron and team membranes not only developed each membrane type, but also membrane surface catalysis and impurity tolerance, creation of thin film membranes, alternative applications such as membrane promoted alkane dehydrogenation, demonstration of scale-up testing, and complete engineering documentation including process and mechanical considerations necessary for inclusion of Eltron membranes in a full scale integrated gasification combined cycle power plant. The results of this project directly led to a new $15 million program funded by the Department of Energy. This new project will focus exclusively on scale-up of this technology as part of the FutureGen initiative
Physical activity and sedentary behavior during pregnancy and postpartum, measured using hip and wrist-worn accelerometers.
BACKGROUND: Physical activity in pregnancy and postpartum is beneficial to mothers and infants. To advance knowledge of objective physical activity measurement during these periods, this study compares hip to wrist accelerometer compliance; assesses convergent validity (correlation) between hip- and wrist-worn accelerometry; and assesses change in physical activity from pregnancy to postpartum. METHODS: We recruited women during pregnancy (n = 100; 2014-2015), asking them to wear hip and wrist accelerometers for 7 days during Trimester 2 (T2), Trimester 3 (T3), and 3-, 6-, 9- and 12-months postpartum. We assessed average wear-time and correlations (axis-specific counts/minute, vector magnitude counts/day and step counts/day) at T2, T3, and postpartum. RESULTS: Compliance was higher for wrist-worn accelerometers. Hip and wrist accelerometers showed moderate to high correlations (Pearson's r 0.59 to 0.84). Hip-measured sedentary and active time differed little between T2 and T3. Moderate-to-vigorous physical activity decreased at T3 and remained low postpartum. Light physical activity increased and sedentary time decreased throughout the postpartum period. CONCLUSIONS: Wrist accelerometers may be preferable during pregnancy and appear comparable to hip accelerometers. As physical activity declines during later pregnancy and may not rebound post birth, support for re-engaging in physical activity earlier in the postpartum period may benefit women
Reliability and validity of the Safe Routes to school parent and student surveys
Abstract Background The purpose of this study is to assess the reliability and validity of the U.S. National Center for Safe Routes to School's in-class student travel tallies and written parent surveys. Over 65,000 tallies and 374,000 parent surveys have been completed, but no published studies have examined their measurement properties. Methods Students and parents from two Charlotte, NC (USA) elementary schools participated. Tallies were conducted on two consecutive days using a hand-raising protocol; on day two students were also asked to recall the previous days' travel. The recall from day two was compared with day one to assess 24-hour test-retest reliability. Convergent validity was assessed by comparing parent-reports of students' travel mode with student-reports of travel mode. Two-week test-retest reliability of the parent survey was assessed by comparing within-parent responses. Reliability and validity were assessed using kappa statistics. Results A total of 542 students participated in the in-class student travel tally reliability assessment and 262 parent-student dyads participated in the validity assessment. Reliability was high for travel to and from school (kappa > 0.8); convergent validity was lower but still high (kappa > 0.75). There were no differences by student grade level. Two-week test-retest reliability of the parent survey (n = 112) ranged from moderate to very high for objective questions on travel mode and travel times (kappa range: 0.62 - 0.97) but was substantially lower for subjective assessments of barriers to walking to school (kappa range: 0.31 - 0.76). Conclusions The student in-class student travel tally exhibited high reliability and validity at all elementary grades. The parent survey had high reliability on questions related to student travel mode, but lower reliability for attitudinal questions identifying barriers to walking to school. Parent survey design should be improved so that responses clearly indicate issues that influence parental decision making in regards to their children's mode of travel to school
Integrating Tobacco Control and Obesity Prevention Initiatives at Retail Outlets
Tobacco products are sold in approximately 375,000 US retail outlets, including convenience stores and pharmacies, which often sell energy-dense, low-nutrient foods and beverages. The Food and Drug Administration's (FDA's) increased authority over tobacco product sales and marketing, combined with declining smoking rates, provides an opportunity to transition tobacco retailers toward healthier retail environments. Unfortunately, research into improving consumer retail environments is often conducted in isolation by researchers working in tobacco control, nutrition, and physical activity. Interdisciplinary efforts are needed to transform tobacco retailers from stores that are dependent on a declining product category, to the sale and promotion of healthful foods and creating environments conducive to active living. The objective of this article is to describe the potential for interdisciplinary efforts to transition retailers away from selling and promoting tobacco products and toward creating retail environments that promote healthful eating and active living
Agricultural R&D, technology and productivity.
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