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111.
BACKGROUND: The agreement on agriculture and the World Trade Organization were major outcomes of the 1986-1994 Uruguay Round (UR) negotiations within the General Agreement on Tariffs and Trade (GATT). The measures under the UR were predicted to increase poverty in developing countries, a serious cause for concern since poverty alleviation is a major goal of developing countries. Thus this paper simulated the impact on poverty of the UR for a net food importing country, Trinidad and Tobago. OBJECTIVE: The objectives of the study were to determine the changes in poverty levels in Trinidad and Tobago that we expected would result from changes in the price levels of food commodities after the removal of trade protection following the UR, and to examine recent trends in poverty in Trinidad and Tobago and the prices of major agricultural exports from the United States, its principal trading partner. METHODS: A regression model (poverty model) was used to determine the relationship between poverty levels and the prices of sensitive imported food commodities (SIFCs) and other key economic variables. Impact models were used to project changes in world market prices of the SIFCs due to the UR, and these price changes were used to predict changes in poverty in Trinidad and Tobago. RESULTS: The results showed a positive elasticity between poverty and the prices of SIFCs. The study also predicted that the average projected increase in price levels of the SIFCs of less than 9% by the year 2000 would cause an increase in poverty in Trinidad and Tobago of less than 4%. CONCLUSIONS: There has been, in fact, a small decline in poverty in Trinidad and Tobago since 1996. The prices of major agricultural exports from the United States have also been falling since 1995. Thus, so far the UR has had no perceptible effects in increasing the prices of food exports from the United States. Also, so far the UR has had no perceptible effect on the poverty level in Trinidad and Tobago. 相似文献
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Kim KH Moldovan N Ke C Espinosa HD Xiao X Carlisle JA Auciello O 《Small (Weinheim an der Bergstrasse, Germany)》2005,1(8-9):866-874
A hard, low-wear probe for contact-mode writing techniques, such as dip-pen nanolithography (DPN), was fabricated using ultrananocrystalline diamond (UNCD). Molding within anisotropically etched and oxidized pyramidal pits in silicon was used to obtain diamond tips with radii down to 30 nm through growth of UNCD films followed by selective etching of the silicon template substrate. The probes were monolithically integrated with diamond cantilevers and subsequently integrated into a chip body obtained by metal electroforming. The probes were characterized in terms of their mechanical properties, wear, and atomic force microscopy imaging capabilities. The developed probes performed exceptionally well in DPN molecular writing/imaging mode. Furthermore, the integration of UNCD films with appropriate substrates and the use of directed microfabrication techniques are particularly suitable for fabrication of one- and two-dimensional arrays of probes that can be used for massive parallel fabrication of nanostructures by the DPN method. 相似文献
114.
The structured design of cryptographically good s-boxes 总被引:2,自引:1,他引:1
We describe a design procedure for the s-boxes of private key cryptosystems constructed as substitution-permutation networks (DES-like cryptosystems). Our procedure is proven to construct s-boxes which are bijective, are highly nonlinear, possess the strict avalanche criterion, and have output bits which act (vitually) independently when any single input bit is complemented. Furthermore, our procedure is very efficient: we have generated approximately 60 such 4 × 4 s-boxes in a few seconds of CPU time on a SUN workstation.This work was partially supported by a grant from the Natural Sciences and Engineering Research Council of Canada. 相似文献
115.
Conducted 3 polydipsia experiments with a total of 26 female Sprague-Dawley rats, 6 of which were implanted with thermodes and thermistors and 2 of which were implanted with thermistors alone in the medial preoptic area or posterior hypothalamus. A cold (5.C) ambient temperature reduced the amount of water consumed by food-deprived Ss tested with a VI schedule of reinforcement, while a warm (30.C) ambient increased water intake. Response rate in the cold was twice that in a neutral temperature. A hot (38.C) ambient suppressed the rate of responding and drinking. Cooling the hypothalamus substantially reduced water intake in a neutral ambient temperature. Ambient temperature affected the volume of a drink but not the frequency of drinking, while hypothalamic cooling affected both volume and frequency. Water temperature had little effect on polydipsia although less cold water was consumed than warm water. It is concluded that schedule-induced polydipsia is a temperature-dependent phenomenon. (39 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
116.
This paper presents a small, annual model of natural gas supply used for policy analysis by the US General Accounting Office. The model incorporates a realistically complex lag structure and complex dynamics while maintaining a simple theoretical framework and manageable size. It simulates the historical record very well and is employed in this paper to generate three scenarios concerning gas supply from 1982–1990 under alternative price control policies. 相似文献
117.
Carlisle E. Moody 《Energy Economics》1996,18(4):295-314
We investigate a short-term forecasting and simulation model of utility fuel demand based on the linear logit model. The forecasting properties of the model are surprisingly good for such a simple econometric model of factor demand. The model ignores the distinctive characteristics of electric utilities (load curves, wheeling, etc.) yet produces remarkably good forecasts at both the national and regional levels. Because the model is based on neoclassical theory it can be used for simulations, making it more useful, and less ad hoc, than a pure forecasting model. 相似文献
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James J. Kwan Rachel Myers Christian M. Coviello Susan M. Graham Apurva R. Shah Eleanor Stride Robert C. Carlisle Constantin C. Coussios 《Small (Weinheim an der Bergstrasse, Germany)》2015,11(39):5305-5314
Ultrasound‐induced bubble activity (cavitation) has been recently shown to actively transport and improve the distribution of therapeutic agents in tumors. However, existing cavitation‐promoting agents are micron‐sized and cannot sustain cavitation activity over prolonged time periods because they are rapidly destroyed upon ultrasound exposure. A novel ultrasound‐responsive single‐cavity polymeric nanoparticle (nanocup) capable of trapping and stabilizing gas against dissolution in the bloodstream is reported. Upon ultrasound exposure at frequencies and intensities achievable with existing diagnostic and therapeutic systems, nanocups initiate and sustain readily detectable cavitation activity for at least four times longer than existing microbubble constructs in an in vivo tumor model. As a proof‐of‐concept of their ability to enhance the delivery of unmodified therapeutics, intravenously injected nanocups are also found to improve the distribution of a freely circulating IgG mouse antibody when the tumor is exposed to ultrasound. Quantification of the delivery distance and concentration of both the nanocups and coadministered model therapeutic in an in vitro flow phantom shows that the ultrasound‐propelled nanocups travel further than the model therapeutic, which is itself delivered to hundreds of microns from the vessel wall. Thus nanocups offer considerable potential for enhanced drug delivery and treatment monitoring in oncological and other biomedical applications. 相似文献