Understanding Differences (understanding + difference)

Distribution by Scientific Domains


Selected Abstracts


Comparative Advantage in Demand: Experimental Evidence of Preferences for Genetically Modified Food in the United States and European Union

JOURNAL OF AGRICULTURAL ECONOMICS, Issue 1 2006
Jayson L. Lusk
Q130; Q170; Q180; C190 Abstract The United States (US) exports more than US$6 billion in agricultural commodities to the European Union(EU) each year, but one issue carries the potential to diminish this trade: use of biotechnology in food production. The EU has adopted more stringent policies towards biotechnology than the US. Understanding differences in European and American policies towards genetically modified (GM) foods requires a greater understanding of consumers' attitudes and preferences. This paper reports results from the first large-scale, cross-Atlantic study to analyse consumer demand for genetically modified food in a non-hypothetical market environment. We strongly reject the frequent if convenient assumption in trade theory that consumer preferences are identical across countries: the median level of compensation demanded by English and French consumers to consume a GM food is found to be more than twice that in any of the US locations. Results have important implications for trade theory, which typically focuses on differences in specialization, comparative advantage and factor endowments across countries, and for on-going trade disputes at the World Trade Organization. [source]


Flood disturbance, algal productivity, and interannual variation in food chain length

OIKOS, Issue 1 2000
Jane C. Marks
The length of a river food chain changed from year to year, shifting with the hydrologic regime. During drought years, grazers suppressed algae across a nutrient gradient, while predators were functionally unimportant. Following flood disturbance, predators suppressed grazers, releasing algae. These results suggest that hydrologic regime, rather than productivity, determines the functional length of this river food chain. Within years, algae and grazer biomass responded to an experimental productivity gradient in patterns predicted by simple trophic models that assume efficient energy transfer. Understanding differences among species within trophic levels, however, was crucial in delineating the controlling interactions. [source]


Differential impacts of habitat heterogeneity on male and female connectivity in a spatially structured pest system

AUSTRAL ECOLOGY, Issue 1 2009
G. S. HAMILTON
Abstract In a previous study, a model of landscape heterogeneity was developed and applied to a spatially structured wild rabbit (Oryctolagus cuniculus) population. That study showed clearly the influence of resource heterogeneity on connectivity levels. The simulation study was based on female movements and used population genetic validation data appropriate for a female study. Most models assume that males and females will exhibit similar patterns, although this has rarely been tested. In the current study we extend the analysis to consider differences between female and male connectivity in the same spatially structured pest system. Amplified fragment length polymorphism (AFLP) markers were screened on the same samples used previously for mtDNA analysis. The mtDNA data were used to validate female results, and AFLP data were used to validate combined male and female results. Connectivity patterns from the two simulations (female, and combined male and female) connectivity patterns showed no association. However, each was concordant with appropriate validation data, showing highly significant associations between pairwise population connectivity and the genetic data. A relative connectivity metric for the combined simulation was regressed against the mean of pairwise ,ST values, with almost 70% of the variation explained by a linear model. Demonstrating differential effects of habitat heterogeneity on male and female connectivity provides further evidence that spatial resource heterogeneity impacts on connectivity. Understanding differences in population connectivity will allow improved predictions of disease spread, local extinctions and recolonizations. Furthermore, modelling such differences in pest systems will allow management plans to be better targeted, for example by strategically introducing diseases for control purposes into populations which exhibit high male connectivity to aid spread, but low female connectivity to inhibit recolonization potential after control. [source]


Progress in cancer screening practices in the United States,

CANCER, Issue 6 2003
Results from the 2000 National Health Interview Survey
Abstract BACKGROUND Understanding differences in cancer screening among population groups in 2000 and successes or failures in reducing disparities over time among groups is important for planning a public health strategy to reduce or eliminate health disparities, a major goal of Healthy People 2010 national cancer screening objectives. In 2000, the new cancer control module added to the National Health Interview Survey (NHIS) collected more detailed information on cancer screening compared with previous surveys. METHODS Data from the 2000 NHIS and earlier surveys were analyzed to discern patterns and trends in cancer screening practices, including Pap tests, mammography, prostate specific antigen (PSA) screening, and colorectal screening. The data are reported for population subgroups that were defined by a number of demographic and socioeconomic characteristics. RESULTS Women who were least likely to have had a mammogram within the last 2 years were those with no usual source of health care (61%), women with no health insurance (67%), and women who immigrated to the United States within the last 10 years (61%). Results for Pap tests within the last 3 years were similar. Among both men and women, those least likely to have had a fecal occult blood test or endoscopy within the recommended screening interval had no usual source of care (14% for men and 18% for women), no health insurance (20% for men and 18% for women), or were recent immigrants (20% for men and 18% for women). An analysis of changes in test use since the 1987 survey indicates that the disparities are widening among groups with no usual source of care. CONCLUSIONS No striking improvements have been observed for the groups with greatest need. Although screening use for most groups has increased since 1987, major disparities remain. Some groups, notably individuals with no usual source of care and the uninsured are falling further behind; and, according to the 2000 data, recent immigrants also experience a significant gap in screening utilization. More attention is needed to overcome screening barriers for these groups if the population benefits of cancer screening are to be achieved. Cancer 2003;97:1528,40. Published 2003 by the American Cancer Society. DOI 10.1002/cncr.11208 [source]