63 research outputs found
Achieving and Maintaining Food Security in the PRC: The Impact on Foreign Policy
The purpose of this dissertation is to examine how the People’s Republic of China has used domestic and foreign policy to achieve and maintain food security. This is a formidable task for the PRC given that it has 20% of the world’s population and only 7% of its arable land. It has been made more formidable by domestic policy errors and its changing position within the international system.
The PRC has evolved from a Marxist revisionist state to one that mixes state capitalism and free enterprise and has become a combination of revisionist and status quo. Such changes lend themselves to process-tracing as a methodology in order to reveal the rationale behind the change and the resulting impact on food security. To capture this evolution, a food paradigm is constructed for various eras that reflect domestic influences on food security. To this is added the international aspect; the choice of what countries it would or could trade with, as needed. Together the domestic and international are combined to obtain a complete view of the food paradigm and resulting food security situation for each era.
In pursuing food security this dissertation will focus on rice, wheat, soybeans, and maize, the prime grains for human consumption and animal feed in the PRC. These grains provide much of the caloric intake of the population as well as being the prime reserve products. The results show that these products have been used as a tool of foreign policy to reward or punish other states by adjusting their imports and exports to send political messages as seen fit. The PRC has always maintained a diversified import supply base, but as imports have continued to grow, the supply base is expanding. Expansion is not through land-grabbing but by contract growing by local farmers in less developed countries and leasing land in developed countries, both on previously uncultivated lands. Simultaneously, there are efforts to improve grain production in African countries, among others. Increasing output there will increase total world supply, an indirect benefit to the PRC food security and to its image abroad
Using Mobile Geographic Information Systems to Improve Operational Efficiency, Data Reliability, and Access in Mine Action
The inherently complex field of mine action, with its many political, financial, and physical considerations, is also a spatial, data-driven field; and as a result, geographic information systems (GIS) stand to play a major role. Spatial data can help address questions such as: Where are the hazardous areas and what has been cleared or cancelled? Where have teams already surveyed? Where should they go next? How many square meters have been cleared? Due to the complexities surrounding assigning tasks and prioritization, standard operating procedures (SOP), quality assurance/quality control (QA/QC) and database design, GIS often gets limited to high-level planning, database cataloging, and end-of-task analysis and reporting. With the improvement of mobile technologies and locationbased services, GIS is poised to play a bigger role in the dayto-day operations of landmine and unexploded ordnance (UXO) clearance
Impact of Baseline Retinal Nonperfusion and Macular Retinal Capillary Nonperfusion on Outcomes in the COPERNICUS and GALILEO Studies.
Purpose To evaluate the impact of baseline retinal capillary nonperfusion (RNP) and macular retinal capillary nonperfusion (MNP) status on outcomes at week 24 (W24). Design Post hoc analyses of 2 phase 3, randomized, double-masked, multicenter, sham-controlled studies. Participants Three hundred sixty-six patients with macular edema secondary to central retinal vein occlusion randomized in COPERNICUS and GALILEO. Methods We randomized patients 3:2 to receive intravitreal aflibercept 2 mg every 4 weeks or sham injections until W24. RNP and MNP were assessed by a masked independent reading center. Main Outcome Measures Proportion of patients with 10 disc areas (DA) or more of RNP and any degree of MNP at W24, relative risks of 10 DA or more of RNP or any degree of MNP at W24 developing, change from baseline in best-corrected visual acuity (BCVA) and central retinal thickness (CRT) by baseline RNP and MNP status, and relationship between baseline RNP and MNP status. Results At baseline, 24.6% of patients showed 10 DA or more of RNP and 72.6% showed MNP, regardless of baseline RNP status. At W24, the pooled proportions of patients in the intravitreal aflibercept and sham groups with 10 DA or more of RNP were 11.6% and 29.0%, respectively (P = 0.0001); the respective proportions with any degree of MNP were 61.2% and 79.5% (P = 0.0008). Relative risks and 95% confidence intervals for intravitreal aflibercept versus sham were 0.4 (0.25–0.62) for 10 DA or more of RNP and 0.8 (0.68–0.90) for MNP, indicating a lower risk for these outcomes with intravitreal aflibercept than with sham. Mean BCVA change was greater in intravitreal aflibercept- versus sham-treated eyes, with less than 10 DA and 10 DA or more of RNP at baseline (+17.5 vs. +0.8 letters and +18.3 vs. −4.1 letters, respectively) and with and without baseline MNP (+15.7 vs. +0.3 letters and +17.1 vs. +0.4 letters, respectively). Agreement between baseline RNP and MNP status was low (κ = 0.12). The proportions of patients with 1 or more ocular serious adverse event in the intravitreal aflibercept- and sham-treated groups, respectively, were 3.2% and 11.3%. Conclusions At W24, visual and anatomic improvements, including perfusion status, were greater in eyes treated with intravitreal aflibercept than in eyes treated with sham, regardless of baseline RNP or MNP status
Sun and sky: Does human vision assume a mixture of point and diffuse illumination when interpreting shape-from-shading?
AbstractPeople readily perceive smooth luminance variations as being due to the shading produced by undulations of a 3-D surface (shape-from-shading). In doing so, the visual system must simultaneously estimate the shape of the surface and the nature of the illumination. Remarkably, shape-from-shading operates even when both these properties are unknown and neither can be estimated directly from the image. In such circumstances humans are thought to adopt a default illumination model. A widely held view is that the default illuminant is a point source located above the observer’s head. However, some have argued instead that the default illuminant is a diffuse source. We now present evidence that humans may adopt a flexible illumination model that includes both diffuse and point source elements. Our model estimates a direction for the point source and then weights the contribution of this source according to a bias function. For most people the preferred illuminant direction is overhead with a strong diffuse component
Submicron and Nanometer Structures Technology and Research
Contains reports on sixteen research projects and a list of publications.Joint Services Electronics Program Contract DAAL03-89-C-0001Joint Services Electronics Program Contract DAAL03-92-C-0001National Science Foundation Grant ECS 90-16437Semiconductor Research Corporation Contract 90-SP-080U.S. Navy - Naval Research Laboratory Contract N00014-90-K-2018IBM CorporationU.S. Air Force - Office of Scientific Research Grant F49620-92-J-0064National Science Foundation Grant DMR 87-19217National Science Foundation Grant DMR 90-22933National Aeronautics and Space Administration Contract NAS8-36748National Aeronautics and Space Administration Grant NAGW-2003National Science Foundation Grant DMR 90-01698Spire Corporatio
Strong Interaction Physics at the Luminosity Frontier with 22 GeV Electrons at Jefferson Lab
This document presents the initial scientific case for upgrading the
Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab (JLab)
to 22 GeV. It is the result of a community effort, incorporating insights from
a series of workshops conducted between March 2022 and April 2023. With a track
record of over 25 years in delivering the world's most intense and precise
multi-GeV electron beams, CEBAF's potential for a higher energy upgrade
presents a unique opportunity for an innovative nuclear physics program, which
seamlessly integrates a rich historical background with a promising future. The
proposed physics program encompass a diverse range of investigations centered
around the nonperturbative dynamics inherent in hadron structure and the
exploration of strongly interacting systems. It builds upon the exceptional
capabilities of CEBAF in high-luminosity operations, the availability of
existing or planned Hall equipment, and recent advancements in accelerator
technology. The proposed program cover various scientific topics, including
Hadron Spectroscopy, Partonic Structure and Spin, Hadronization and Transverse
Momentum, Spatial Structure, Mechanical Properties, Form Factors and Emergent
Hadron Mass, Hadron-Quark Transition, and Nuclear Dynamics at Extreme
Conditions, as well as QCD Confinement and Fundamental Symmetries. Each topic
highlights the key measurements achievable at a 22 GeV CEBAF accelerator.
Furthermore, this document outlines the significant physics outcomes and unique
aspects of these programs that distinguish them from other existing or planned
facilities. In summary, this document provides an exciting rationale for the
energy upgrade of CEBAF to 22 GeV, outlining the transformative scientific
potential that lies within reach, and the remarkable opportunities it offers
for advancing our understanding of hadron physics and related fundamental
phenomena.Comment: Updates to the list of authors; Preprint number changed from theory
to experiment; Updates to sections 4 and 6, including additional figure
Applications of Location-Based Services and Mobile Technologies in K-12 Classrooms
The use of location-based services and mobile technologies is increasing in K-12 classrooms. In this article, we describe the history and the current use of these tools in the innovative Geospatial Semester project in Virginia. We share a number of examples where students are creating projects of their own interest that use editable feature services, mobile data collection and other cutting-edge technologies. These projects help students build their spatial thinking and problem-solving skills, and help teachers build conceptual understanding in a variety of domains
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