8,218 research outputs found
Average vs. Marginal Risk Aversion: Reconciling Simultaneously Risk Averse and Risk Loving Behavior
Risk and Uncertainty,
Combining Consumer Valuation Research with Sensory Science Techniques: A Laboratory Experiment
In this research, we integrated an experimental auction with sensory science techniques—namely, trained sensory panels used to analyze the sensory attributes of wines—to examine the effects of objective and sensory information in the market for California-produced Cabernet Sauvignons. The experiment permitted observation of consumer valuation for sensory attributes of wine, appellations, expert ratings, and wineries. Participants submitted bids each time they received new information about the wines. The balanced experimental design permits evaluation of the effects of consumer characteristics on attribute valuation. We had 236 people participate in the research, which consisted of nine rounds of bidding and one round of hedonic liking scores. Rounds 5-9 repeated the structure of information released in rounds 1-4, but added sensory information, yielding 472 observations for each type of information (e.g. appellation, expert rating, winery). We obtain a total of 8496 valuations, or bids and 944 hedonic “liking” ratings, as well as demographic information, wine consumption data, and a wine knowledge score for each consumer. The results of the research agree with many of the previously held notions about valuation of wine by consumers. Participants value Cabernet Sauvignons from Napa Valley and Sonoma County and their sub-appellations more than wines labeled with the California appellation. Bids for wines rated by experts such as the Wine Advocate (Robert Parker) or Wine Spectator increased as the experts’ ratings increased. However, we also find that consumer characteristics are very important in explaining WTP for wine attributes. The contributions of prestigious appellations to the value of Cabernet Sauvignons depended on consumer characteristics. Willingness to pay was highly correlated with sensory evaluation, but even after tasting the wine, appellation and expert ratings still mattered for WTP. Overall, the research describes a significant amount of heterogeneity in the preferences for sensory characteristics of wine, and that individual characteristics systematically explain many of the differences in valuation of wine attributes.Experimental Economics, Willingness to Pay, WTP, Wine, Consumer Valuation, Hedonic Pricing, Sensory Analysis, Demand and Price Analysis, Food Consumption/Nutrition/Food Safety, Marketing, Research Methods/ Statistical Methods,
Amphibians and reptiles of C. E. Miller Ranch and the Sierra Vieja, Chihuahuan Desert, Texas, USA
We report the occurrence of 50 species of amphibians and reptiles recently collected on C. E. Miller Ranch and the Sierra Vieja in the Chihuahuan Desert of Texas, USA and describe their perceived distribution and abundance across various habitat associations of the region. Our recent surveys follow intense, historic sampling of amphibians and reptiles from this region in 1948. Of the 50 species detected in recent surveys, six were not collected in 1948 and an additional three species documented in 1948 have yet to be detected in a 14-year period of recent surveys. Combining data from both historic and recent surveys, a total of 53 species of amphibians and reptiles are known from the ranch (11 amphibians, 42 reptiles). Land stewardship and conservation practices have likely contributed to the persistence of the majority of these species through time. Additionally, we discuss the status of amphibians and reptiles not collected during recent surveys and comment on potential species that have not yet been detected
Visualizing genetic constraints
Principal Components Analysis (PCA) is a common way to study the sources of
variation in a high-dimensional data set. Typically, the leading principal
components are used to understand the variation in the data or to reduce the
dimension of the data for subsequent analysis. The remaining principal
components are ignored since they explain little of the variation in the data.
However, evolutionary biologists gain important insights from these low
variation directions. Specifically, they are interested in directions of low
genetic variability that are biologically interpretable. These directions are
called genetic constraints and indicate directions in which a trait cannot
evolve through selection. Here, we propose studying the subspace spanned by low
variance principal components by determining vectors in this subspace that are
simplest. Our method and accompanying graphical displays enhance the
biologist's ability to visualize the subspace and identify interpretable
directions of low genetic variability that align with simple directions.Comment: Published in at http://dx.doi.org/10.1214/12-AOAS603 the Annals of
Applied Statistics (http://www.imstat.org/aoas/) by the Institute of
Mathematical Statistics (http://www.imstat.org
The Last Refuge of Official Discrimination: The Federal Funding Exception to California\u27s Proposition 209
Cloning, sequencing, and characterization of the hexahydro-1,3,5-trinitro-1,3,5-triazine degradation gene cluster from Rhodococcus rhodochrous
Hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) is a high explosive which presents an environmental hazard as a major land and groundwater contaminant. Rhodococcus rhodochrous strain 11Y was isolated from explosive contaminated land and is capable of degrading RDX when provided as the sole source of nitrogen for growth. Products of RDX degradation in resting-cell incubations were analyzed and found to include nitrite, formaldehyde, and formate. No ammonium was excreted into the medium, and no dead-end metabolites were observed. The gene responsible for the degradation of RDX in strain 11Y is a constitutively expressed cytochrome P450-like gene, xpLA, which is found in a gene cluster with an adrenodoxin reductase homologue, xplB. The cytochrome P450 also has a flavodoxin domain at the N terminus. This study is the first to present a gene which has been identified as being responsible for RDX biodegradation. The mechanism of action of XplA on RDX is thought to involve initial denitration followed by spontaneous ring cleavage and mineralization
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