29,160 research outputs found
DETERMINANTS OF CONSUMER ATTITUDES AND PURCHASE INTENTIONS WITH REGARD TO GM FOODS
Consumer acceptance of genetically modified (GM) products has become a vital factor in determining how prosperous the markets for GM products will be in the future. This phenomenon creates increased interest in understanding consumer attitudes and purchase intentions with regard to GM foods. Thus, this paper presents results based on a contingent valuation questionnaire designed to assess consumer knowledge, awareness and willingness to purchase GM-tomatoes in Huntsville metropolitan area, Alabama. The results suggest that attitudes and purchase decisions concerning GM foods are generally negative, highly complex and are based on several factors.Consumer/Household Economics,
Combustion instability prediction using a nonlinear bipropellant vaporization model
Combustion instability prediction using nonlinear bipropellant vaporization mode
Do Childhood Vaccines Have Non-Specific Effects on Mortality
A recent article by Kristensen et al. suggested that measles vaccine and bacille CalmetteâGuĂ©rin (BCG) vaccine might\ud
reduce mortality beyond what is expected simply from protection against measles and tuberculosis. Previous reviews of the potential effects of childhood vaccines on mortality have not considered methodological features of reviewed studies. Methodological considerations play an especially important role in observational assessments, in which selection factors for vaccination may be difficult to ascertain. We reviewed 782 English language articles on vaccines and childhood mortality and found only a few whose design met the criteria for methodological rigor. The data reviewed suggest that measles vaccine delivers its promised reduction in mortality, but there is insufficient evidence to suggest a mortality benefit above that caused by its effect on measles disease and its sequelae. Our review of the available data in the literature reinforces how difficult answering these considerations has been and how important study design will be in determining the effect of specific vaccines on all-cause mortality.\u
Trust and trustworthiness
What is it to trust someone? What is it for someone to be trustworthy? These are the two main questions that this paper addresses. There are various situations that can be described as ones of trust, but this paper considers the issue of trust between individuals. In it, I suggest that trust is distinct from reliance or cases where someone asks for something on the expectation that it will be done due to the different attitude taken by the trustor. I argue that the trustor takes Holton's 'participant stance' and this distinguishes trust from reliance. I argue that trustworthiness is different from reliability and that an account of trustworthiness cannot be successful whilst ignoring the point that aligning trustworthiness with reliability removes the virtue from being trustworthy. On the question of what it is distinguishes trustworthiness from reliability, I argue that the distinction is in the opportunity for the trustee to act against the wishes of the trustor and the trustee's consideration of the value of the trust that has been placed in them by the trustor
Full-time dynamics of modulational instability in spinor Bose-Einstein condensates
We describe the full-time dynamics of modulational instability in F=1 spinor
Bose-Einstein condensates for the case of the integrable three-component model
associated with the matrix nonlinear Schroedinger equation. We obtain an exact
homoclinic solution of this model by employing the dressing method which we
generalize to the case of the higher-rank projectors. This homoclinic solution
describes the development of modulational instability beyond the linear regime,
and we show that the modulational instability demonstrates the reversal
property when the growth of the modulation amplitude is changed by its
exponential decay.Comment: 6 pages, 2 figures, text slightly extended, a reference adde
Evaluation Of Methods For Estimating Daily Reference Crop Evapotranspiration At A Site In The Humid Southeast United States
Estimated daily reference crop evapotranspiration (ETo) is normally used to determine the water requirement of crops using the crop factor method. Many ETo estimation methods have been developed for different types of climatic data, and the accuracy of these methods varies with climatic conditions. In this study, pairâwise comparisons were made between daily ETo estimated from eight different ETo equations and ETo measured by lysimeter to provide information helpful in selecting an appropriate ETo equation for the Cumberland Plateau located in the humid Southeast United States. Based on the standard error of the estimate (Syx), the relationship between the estimated and measured ETo was the best using the FAOâ56 PenmanâMonteith equation (coefficient of determination (r2) = 0.91, Syx = 0.31 mm dâ1, and a coefficient of efficiency (E) = 0.87), followed by the Penman (1948) equation (r2 = 0.91, Syx = 0.34 mm dâ1, and E = 0.88), and Turcâs equation (r2 = 0.90, Syx = 0.36 mm dâ1, and E = 0.88). The FAOâ24 Penman and PriestlyâTaylor methods overestimated ETo, while the Makkink equation underestimated ETo. The results for the HargreavesâSamani equation showed low correlation with lysimeter ETo data (r2 = 0.51, Syx = 0.68 mm dâ1, and E = 0.20), while those for the Kimberly Penman were reasonable (r2 = 0.87, Syx = 0.40 mm dâ1, and E = 0.87). These results support the adoption of the FAOâ56 PenmanâMonteith equation for the climatological conditions occurring in the humid Southeast. However, Turcâs equation may be an attractive alternative to the more complex PenmanâMonteith method. The Turc method requires fewer input parameters, i.e., mean air temperature and solar irradiance data only
Interaction of Stress, Lead Burden, and Age on Cognition in Older Men: The VA Normative Aging Study
BACKGROUND. Low-level exposure to lead and to chronic stress may independently influence cognition. However, the modifying potential of psychosocial stress on the neurotoxicity of lead and their combined relationship to aging-associated decline have not been fully examined. OBJECTIVES. We examined the cross-sectional interaction between stress and lead exposure on Mini-Mental State Examination (MMSE) scores among 811 participants in the Normative Aging Study, a cohort of older U.S. men. METHODS. We used two self-reported measures of stress appraisal-a self-report of stress related to their most severe problem and the Perceived Stress Scale (PSS). Indices of lead exposure were blood lead and bone (tibia and patella) lead. RESULTS. Participants with higher self-reported stress had lower MMSE scores, which were adjusted for age, education, computer experience, English as a first language, smoking, and alcohol intake. In multivariable-adjusted tests for interaction, those with higher PSS scores had a 0.57-point lower (95% confidence interval, -0.90 to 0.24) MMSE score for a 2-fold increase in blood lead than did those with lower PSS scores. In addition, the combination of high PSS scores and high blood lead categories on one or both was associated with a 0.05-0.08 reduction on the MMSE for each year of age compared with those with low PSS score and blood lead level (p < 0.05). CONCLUSIONS. Psychological stress had an independent inverse association with cognition and also modified the relationship between lead exposure and cognitive performance among older men. Furthermore, high stress and lead together modified the association between age and cognition.National Institutes of Health (R01ES07821, R01HL080674, R01HL080674-02S1, R01ES013744, ES05257-06A1, P20MD000501, P42ES05947, ES03918-02); National Center for Research Resources General Clinical Research Center (M01RR02635); Leaves of Grass Foundation; United States Department of Veterans Affair
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