Testing of Great Bay Oysters for Two Protozoan Pathogens

Two protozoan pathogens, Haplosporidium nelsoni (MSX) and Perkinsus marinus (Dermo) are known to be present in Great Bay oysters. With funds provided by the Piscataqua Region Estuaries Partnership (PREP), the Marine Fisheries Division of the New Hampshire Fish and Game Department (NHF&G) continues to assess the presence and intensity of both of these disease conditions in oysters from the major natural beds within the Great Bay estuarine system and at selected aquaculture sites. Histological examinations of Great Bay oysters have also revealed other endoparasites

The M\"obius function of generalized subword order

Let P be a poset and let P* be the set of all finite length words over P. Generalized subword order is the partial order on P* obtained by letting u \leq w if and only if there is a subword u' of w having the same length as u such that each element of u is less than or equal to the corresponding element of u' in the partial order on P. Classical subword order arises when P is an antichain, while letting P be a chain gives an order on compositions. For any finite poset P, we give a simple formula for the Mobius function of P* in terms of the Mobius function of P. This permits us to rederive in a easy and uniform manner previous results of Bjorner, Sagan and Vatter, and Tomie. We are also able to determine the homotopy type of all intervals in P* for any finite P of rank at most 1.Comment: 29 pages, 4 figures. Incorporates referees' suggestions; to appear in Advances in Mathematic

A model for evolution and extinction

We present a model for evolution and extinction in large ecosystems. The model incorporates the effects of interactions between species and the influences of abiotic environmental factors. We study the properties of the model by approximate analytic solution and also by numerical simulation, and use it to make predictions about the distribution of extinctions and species lifetimes that we would expect to see in real ecosystems. It should be possible to test these predictions against the fossil record. The model indicates that a possible mechanism for mass extinction is the coincidence of a large coevolutionary avalanche in the ecosystem with a severe environmental disturbance.Comment: Postscript (compressed etc. using uufiles), 16 pages, with 15 embedded figure

National Transonic Facility status

The National Transonic Facility (NTF) was operational in a combined checkout and test mode for about 3 years. During this time there were many challenges associated with movement of mechanical components, operation of instrumentation systems, and drying of insulation in the cryogenic environment. Most of these challenges were met to date along with completion of a basic flow calibration and aerodynamic tests of a number of configurations. Some of the major challenges resulting from cryogenic environment are reviewed with regard to hardware systems and data quality. Reynolds number effects on several configurations are also discussed

Techniques for aerothermal tests of large, flightweight thermal protection panels in a Mach 7 wind tunnel

Thermal performance and structural integrity are experimentally evaluated in the Langley 8-ft high temperature structures tunnel, which uses a combustion products test medium to provide realistic combinations of aerodynamic heating and loading. Recently developed techniques provide independent control of rate and magnitude of surface heating and differential pressure, protection against adverse acoustics buffeting during facility starting and stopping, programed radiant heating before exposing test panels to the high energy stream, and infrared radiometry for detailed surface temperatures. These techniques were verified repeatedly by return of useful data on metallic and nonmetallic panel concepts of reusable surface insulation

THE SPARTA Model: An Econometric Analysis of Consumer Behaviour under Risk

This paper explores the role of trust in food safety information in determining consumer choice in relation to socio-demographic effects and other determinants. The complexity of factors influencing the way a consumer processes food safety information makes it difficult to develop adequate risk communication strategies. This is, however, a priority for current European policy and this paper tries to answer some key questions: (1) can the consumer be segmented into socio-demographic groups in relation to their trust in food safety information? (2) are country and cultural differences relevant in the way food safety information is processed? (3) how do risk perception and trust in food safety information influence food choice in relation to other determinants? (4) How does a food scare alter the weight of these determinants? (5) How do information sources differ in terms of how they impact on consumers risk perception and behaviours? To provide some answers to the above questions, we propose a modelling framework which extends the Theory of Planned Behaviour to account for risk perception and trust and allows for country-specific effects. The model is tested on the impact of salmonella information on chicken consumption choices across five European countries, France, Germany, Italy, Netherlands and the United Kingdom, based on a nationally representative survey for a total of 2725 face-to-face interviews. Results show that although no relationship emerges between socio-demographics variables and the trust placed by consumer in food safety information, although country differences are relevant. The findings also suggest that the policy priority should be on building and maintaining trust in food and health authorities, and research institutions.food safety information, trust, risk perception, Theory of Planned Behaviour, chicken, Consumer/Household Economics, Food Consumption/Nutrition/Food Safety,

Risk perception and chicken consumption in the avian flu age - a consumer behaviour study on food safety information

As the avian flu pandemic threatens Europe, consumer awareness of the theoretical possibility of contraction of the avian flu virus through consumption of chicken saw a decline in demand at the end of 2005, with peaks between 40% - 50% in Southern European countries such as Italy whilst having little impact on demand in Northern countries like the UK. Such food scares, coupled with an increasing awareness of food safety issues by the general public, highlight the importance of evaluating the perceived risks associated with food purchasing and consumption are paramount in order to provide effective policy communication in this area. There is considerable empirical evidence that different consumers respond to food risk communication in different ways. This implies that policymakers and food firms cannot rely on a single public information strategy for emerging food risks. Furthermore, the impact of food safety information varies significantly according to the sources that provide it. Using data are from a nationally representative pan-European survey of 2 725 respondents from five EU countries (France, Germany, Italy, Netherlands and the United Kingdom), we show that in a situation of increased perceived risk hence increased levels of involvement households across the EU are likely to respond in culturally specific ways which suggest a need for country level policy design.Food Consumption/Nutrition/Food Safety,

Food Scares and Consumer Behaviour: A European Perspective

In this paper a consumer food choice model based on the Theory of Planned Behaviour (TPB) is extended to account for risk perception and trust. The data are from a nationally representative European survey of 2 725 respondents from five countries, France, Germany, Italy, Netherlands and the United Kingdom. The model relates the intention to purchase chicken in an extended TPB framework, which incorporates risk perceptions, and trust in alternative sources of food safety information. This model was run for two behaviours of interest: the standard likelihood of intention to purchase and the likelihood of intention to purchase conditional on news about a salmonella incident. The model has good predictive power and shows distinct country differences. Only in the case of a food scare do risk perceptions and trust come into play. The findings suggest that the government policy priority should be on building and maintaining trust in food and health authorities, and research institutions, while food chain actors could eliminate many of the adverse consequences of a food scare if they could build public trust. Interestingly there is no relationship between socio-demographic variables and the trust placed by consumers in food safety information.food safety information, trust, risk perception, Theory of Planned Behaviour, chicken, Food Consumption/Nutrition/Food Safety, D80, D12, Q18,

Evolution of Cooperative Thought, Theory, and Purpose

The evolution of agricultural cooperative thought, theory, and purpose in the United States is reviewed from the standpoint of the reemergence of interest in how cooperatives can provide some of the security and benefits that might be lost with gradual phasing out of federal government farm support programs. By accomplishing group action for self-help, the early development of cooperatives drew considerable attention from economists, social theorists, and politicians. Alternative schools of cooperative thought developed, but most proponents of cooperatives regarded them as having enormous potential to provide a public service role in building a more economically stable and democratic society This paper also surveys how cooperative theory was developed more rigorously in the post-WWII period. It has provided better analytical tools for understanding how and why cooperatives have changed in response to technological and economic developments, as well as to social trends, like individualism. Given the new perspectives on cooperative theory and the scope of changes in how cooperatives operate and are structured, cooperatives have even greater potential for coordinating self-help actions, but this potential needs the support of cooperative education services.Agribusiness,

Stochastic Dominance in Wheat Variety Development and Release Strategies

Variety development and release decisions involve tradeoffs between yields and characteristics valued by end-users, as well as uncertainties about agronomic, quality, and economic variables. In this study, methods are developed to determine the value of varieties to growers and end-users including the effects of variability in economic, agronomic, and quality variables. The application is to hard red spring (HRS) wheat, a class of wheat for which these tradeoffs and risks are particularly apparent. Results indicate two experimental varieties provide improvements in grower and end-user value, relative to incumbents. Stochastic dominance techniques and statistical tests are applied to determine efficient sets and robustness of the results. A risk-adjusted portfolio model, which simultaneously incorporates correlations between grower and end-use characteristics, is also developed to compare the portfolio value of varieties.end-user value, grower value, portfolio value, stochastic dominance, tradeoffs, variety development, wheat, Crop Production/Industries,