25,361 research outputs found
Social norms and human normative psychology
Our primary aim in this paper is to sketch a cognitive evolutionary approach for developing explanations of social change that is anchored on the psychological mechanisms underlying normative cognition and the transmission of social norms. We throw the relevant features of this approach into relief by comparing it with the self-fulfilling social expectations account developed by Bicchieri and colleagues. After describing both accounts, we argue that the two approaches are largely compatible, but that the cognitive evolutionary approach is well- suited to encompass much of the social expectations view, whose focus on a narrow range of norms comes at the expense of the breadth the cognitive evolutionary approach can provide
Identifying biotic determinants of historic American eel (Anguilla rostrata) distributions
Traditionally, ecologists studying large scale patterns in species distributions emphasize abiotic variables over biotic interactions. Noting that both abiotic & biotic variables likely determine distributions of all organisms, many ecologists now aim for a more comprehensive view of species distributions, inclusive of both abiotic and biotic components (Soberón 2007)
FARM LEVEL DYNAMIC ANALYSIS OF SOIL CONSERVATION: AN APPLICATION TO THE PIEDMONT AREA OF VIRGINIA
A conceptual optimal control theory model which considers farm level decision making with respect to soil management is developed. A simplified version of the theoretical model is applied to the Piedmont area of Virginia. The model includes the productivity impacts of both soil erosion and technological progress. Both the theoretical model and its empirical application are improvements over previous efforts. Results suggest that farmers in the study area can achieve substantial reductions in soil erosion by adopting alternative farming practices.Farm Management,
THE INFLUENCE OF TECHNOLOGICAL PROGRESS ON THE LONG RUN FARM LEVEL ECONOMICS OF SOIL CONSERVATION
The complementary interaction between topsoil depth and technical progress for winter wheat in the Palouse region was found to strengthen the long run payoff to conservation tillage. Nonetheless, conservation tillage was found to be competitive with conventional tillage only if its current yield disadvantages were eliminated. Conservation tillage was relatively more competitive on shallower topsoils and for longer planning horizons. Short-term subsidies coupled with research directed towards reducing the cost and yield disadvantages of conservation tillage in the Palouse were advocated to maintain long-term soil productivity.Land Economics/Use, Research and Development/Tech Change/Emerging Technologies,
Bayesian Estimation of The Impacts of Food Safety Information on Household Demand for Meat and Poultry
Consumer reaction to changes in the amount of food safety information on beef, pork, and poultry available in the media is the focus of this study. Specifically, any differences in consumer reactions due to heterogeneous household characteristics are investigated. The data used in this study are monthly data from the Nielsen Homescan panel and cover the time period January 1998 to December 2005. These panel data contain information on household purchases of fresh meat and poultry as well as demographic characteristics of the participating households. The data used to describe food safety information were obtained from searches of newspapers using the Lexis-Nexis academic search engine. Consumer reactions are modeled in this study using a demand system that allows for both discrete and continuous choice situations. A seemingly unrelated regression (SUR) tobit model is estimated using a Gibbs sampler with data augmentation. A component error structure (random effects model) is incorporated into the SUR tobit model to account for unobserved heterogeneity of households making repeated purchases over time. Estimates of food safety elasticities calculated from the random effects SUR tobit model suggest that food safety information does not have a statistically or economically significant effect on household purchases of meat and poultry.food safety, panel data, Gibbs sampler, component error, Agricultural and Food Policy, Consumer/Household Economics, Food Consumption/Nutrition/Food Safety,
Binary Neutron Star Merger Remnants as Sources of Cosmic Rays Below the "Ankle"
We investigate non-thermal electron and nuclei energy losses within the
binary neutron star merger remnant produced by the event GW170817. The lack of
a cooling feature within the detected synchrotron emission from the source is
used to constrain the magnetic field at the mG level, assuming that this
emission is electron synchrotron in origin, and that the accelerated spectrum
in the electrons follows the form . The level of
subsequent gamma-ray emission from the source is demonstrated to provide a
further constraint on the source magnetic field strength. We also put forward
alternative strong (G) magnetic field scenarios able to support this
emission. For such stronger fields, the photo-disintegration of non-thermal
nuclei within the source is considered, and a bottleneck period of 5-30
days is found when this process peaks. We find that this class of source is in
principle able to support the population of cosmic rays detected at Earth below
the "ankle".Comment: Accepted for publication in Astropart. Phy
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