20,382 research outputs found
Arkansas Small-Grain Cultivar Performance Tests 2004-2005
Small-grain cultivar performance tests are conducted each year in Arkansas by the Arkansas Agricultural Experiment Station, Department of Crop, Soil and Environmental Sciences. The tests provide information to companies developing cultivars and/or marketing seed within the state and aid the Arkansas Cooperative Extension Service in formulating cultivar recommendations for smallgrain producers
Effects of Information about Invasive Species on Risk Perception and Seafood Demand by Gender and Race
In this paper we consider the effects of negative and positive risk information on perceived seafood risks and seafood consumption by gender and race. The data is from a Mid-Atlantic survey of coastal seafood consumers. We elicit risk perceptions in three risk scenarios with a dichotomous choice with a follow-up question format. We elicit continuous revealed and stated preference seafood consumption in nine risk and price scenarios. Analysis in four gender and race categories indicates that demographic groups respond to the positive and negative information in different ways. Communication of risk information as risk mitigation policy is a challenge. Key Words:
The Welfare Effects of Pfiesteria-Related Fish Kills: A Contingent Behavior Analysis of Seafood Consumers
We use contingent behavior analysis to study the effects of pfiesteria-related fish kills on the demand for seafood in the Mid-Atlantic region. We estimate a set of demand difference models based on individual responses to questions about seafood consumption in the presence of fish kills and with different amounts of information provided about health risks. We use a random-effects Tobit model to control for correlation across each observation and to account for censoring. We find that (i) pfiesteria-related fish kills have a significant negative effect on the demand for seafood even though the fish kills pose no known threat to consumers through sea-food consumption, (ii) seafood consumers are not responsive to expert risk information designed to reassure them that seafood is safe in the presence of a fish kill, and (iii) a mandatory seafood inspection program largely eliminates the welfare loss incurred due to misinformation.pfiesteria, seafood demand, non-market valuation, Resource /Energy Economics and Policy,
Calibration of Low-Frequency, Wide-Field Radio Interferometers Using Delay/Delay-Rate Filtering
We present a filtering technique that can be applied to individual baselines
of wide-bandwidth, wide-field interferometric data to geometrically select
regions on the celestial sphere that contain primary calibration sources. The
technique relies on the Fourier transformation of wide-band frequency spectra
from a given baseline to obtain one-dimensional "delay images", and then the
transformation of a time-series of delay images to obtain two-dimensional
"delay/delay-rate images." Source selection is possible in these images given
appropriate combinations of baseline, bandwidth, integration time and source
location. Strong and persistent radio frequency interference (RFI) limits the
effectiveness of this source selection owing to the removal of data by RFI
excision algorithms. A one-dimensional, complex CLEAN algorithm has been
developed to compensate for RFI-excision effects. This approach allows CLEANed,
source-isolated data to be used to isolate bandpass and primary beam gain
functions. These techniques are applied to data from the Precision Array for
Probing the Epoch of Reionization (PAPER) as a demonstration of their value in
calibrating a new generation of low-frequency radio interferometers with wide
relative bandwidths and large fields-of-view.Comment: 17 pages, 6 figures, 2009AJ....138..219
The Welfare Effects of Pfiesteria-Related Fish Kills in Seafood Markets: A Contingent Behavior Analysis
We use contingent behavior analysis to study the effects of Pfiesteria related fish kills on the demand for seafood in the Mid-Atlantic region. We use a phone-mail-phone survey to look at the effects of various information provision mechanisms used to ameliorate the effects of misinformation regarding fish kills. A set of demand difference models are estimated based on individual responses to multiple questions about seafood consumption with and without fish kills present and with various health risk information treatments. Random effects Tobit models are used to control for the panel nature of responses and natural censoring of the stated responses. We find that 1) Pfiesteria related fish kills have a significant negative effect on the demand for seafood, 2) seafood consumers are nonresponsive to expert risk information designed to reassure consumers that seafood is safe in the presence of a fish kill, and 3) a mandatory seafood inspection program completely eliminates avoidance costs incurred due to misinformation. We estimate that the aggregate avoidance costs incurred in the month immediately following a Pfiesteria related fish kill is 130 million.
Effect of pressure on the crystal structure of L-serine-I and the crystal structure of L-serine-II at 5.4 GPa
Adaptive clinical trials incorporating treatment selection and evaluation: methodology and application in progressive multiple sclerosis
In progressive multiple sclerosis (MS) irreversible disability often takes many years to accumulate as a result prolonged trials are required to assess the benefits of therapies. There is a need to understand the relationship between short-term outcome measures such as MRI endpoints and long-term clinical outcomes in progression to determine the evolution of the disease early on. Thus, the common phase I-II-III paradigm for clinical trial design with separate trials for each phase may not be appropriate
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