Zoonotic potential of Salmonella enterica carried by pet tortoises

The prevalence of Salmonella in chelonians is not known in the UK and it is not clear whether such Salmonella strains would be pathogenic for human beings. Some strains, such as members of the Arizonae subgroup, may be unable to cause anything more than very mild disease. To determine the carriage of Salmonella in pet tortoises, cloacal swabs were taken for culture. Salmonella enterica Group D was isolated from 5 of the 89 samples. All five were from the same household of seven tortoises. Salmonella isolates were shown by PCR to carry the invA and spiC genes associated with pathogenicity islands 1 and 2. Each isolate carried both genes indicating they had the genetic basis for disease and enterocyte invasion in human beings. The study indicates a low rate of asymptomatic carriage among the general population of pet tortoises. However, it does suggest that those Salmonella strains colonising the tortoise can carry Salmonella pathogenicity island (SPI)-1 and SPI-2 conferring the potential to cause disease in human beings and other animals

Adaptation to Climate Change: Land Use and Livestock Management Change in the U.S.

Replaced with revised version of paper 01/26/11Climate Change, Stocking Rate, Land Use, Livestock Management, Environmental Economics and Policy, Land Economics/Use, Livestock Production/Industries,

A modeling analysis program for the JPL table mountain Io sodium cloud data

Research in the third and final year of this project is divided into three main areas: (1) completion of data processing and calibration for 34 of the 1981 Region B/C images, selected from the massive JPL sodium cloud data set; (2) identification and examination of the basic features and observed changes in the morphological characteristics of the sodium cloud images; and (3) successful physical interpretation of these basic features and observed changes using the highly developed numerical sodium cloud model at AER. The modeling analysis has led to a number of definite conclusions regarding the local structure of Io's atmosphere, the gas escape mechanism at Io, and the presence of an east-west electric field and a System III longitudinal asymmetry in the plasma torus. Large scale stability, as well as some smaller scale time variability for both the sodium cloud and the structure of the plasma torus over a several year time period are also discussed

Animal Disease Related Pre-event Investment and Post-event Compensation: A Multi-agent Problem

We employ a game-theoretic principal agent framework to analyze the individual farmer and governmental behavior pre- and post-animal disease outbreak. We examine the gap between the privately optimal and socially optimal levels of ex ante biosecurity investment and then investigate how a well-designed differentiated compensation scheme can close this gap. Our results also show that the privately optimal investment is generally lower than the first best socially optimal level, and a well-designed differentiated compensation scheme conditional on ex ante biosecurity investment can induce private preventive investment at least greater than the second best socially optimal level when the government face constraints, or even increase approaching the first best socially optimal level. Furthermore, our results suggest that compensation schemes be expanded to encompass features that provide incentives for ex ante biosecurity investment and ex post truthful disclosure. Specifically inclusion of the following two mechanisms is warranted: (a) a penalty for farms who are found to have disease incidence but have not disclosed that information.Risk and Uncertainty,

Economics of Homeland Security: Carcass Disposal and the Design of Animal Disease Defense

In an effort to bolster confidence and protect the nation the U.S. government through agencies like the Department of Homeland Security is identifying vulnerabilities and evolving strategies for protection. Agricultural food supply is one identified vulnerable area, and animal disease defense is one of the major concerns there under. Should an outbreak of animal disease occur, it is likely to have a mass slaughter and disposal of animal carcasses. The current existing policy, mainly including slaughter policy and strict movement bans, may be not sufficient to control disease spread at reasonable cost. We address the issue modeling vaccination as a supporting strategy with later slaughter of animals and argue that vaccination can decrease slaughter and disposal cost in the case of emergency. Our results show that (a) Vaccination gains time to slow down the flow of slaughter, thereafter the disposal operation of animal carcasses. By smoothing slaughter/disposal flow, vaccination likely decreases slaughter and disposal cost; (b) Vaccination likely reduce the total amount of slaughter and disposal of animals mainly because vaccinated animals shed less and disease spread slower; and (c) Vaccination becomes more valuable in reducing slaughter and disposal costs when the marginal cost of vaccination falls, the even size of disease outbreak is larger, the disease is more contagious and spreads faster, and/or vaccines are more effective in controlling disease spread.Food Consumption/Nutrition/Food Safety,

CLIMATE CHANGE IMPACTS ON US AGRICULTURE

There is general consensus in the scientific literature that human-induced climate change has taken place and will continue to do so over the next century. The Fourth Assessment Report (AR4) of the Intergovernmental Panel on Climate Change concludes with “very high confidence” that anthropogenic activities such as fossil fuel burning and deforestation have affected the global climate. The AR4 also indicates that global average temperatures are expected to increase by another 1.1°C to 5.4°C by 2100, depending on the increase in atmospheric concentrations of greenhouse gases that takes place during this time. Increasing atmospheric carbon dioxide levels, temperature increases, altered precipitation patterns and other factors influenced by climate have already begun to impact U.S. agriculture. Climate change will continue to have significant effects on U.S. agriculture, water resources, land resources, and biodiversity in the future as temperature extremes begin exceeding thresholds that harm crop growth more frequently and precipitation and runoff patterns continue to change. In this study, we provide an assessment of the potential long-term implications of climate change on landowner decisions regarding land use, crop mix, and production practices in the U.S., combining a crop process model (Environmental Policy Integrated Climate model) and an economic model of the U.S. forestry and agricultural sector (Forest and Agricultural Sector Optimization Model). Agricultural producers have always faced numerous production and price risks, but forecasts of more rapid changes in climatic conditions in the future have raised concerns that these risks will increase in the future relative to historical conditions.climate change, crop yields, EPIC, FASOM, Crop Production/Industries, Environmental Economics and Policy, International Relations/Trade, Land Economics/Use, Resource /Energy Economics and Policy, C61, Q18, Q54,

Quantitative analysis of defects in silicon. Silicon sheet growth development for the large are silicon sheet task of the low-cost solar array project

One hundred and seventy four silicon sheet samples were analyzed for twin boundary density, dislocation pit density, and grain boundary length. Procedures were developed for the quantitative analysis of the twin boundary and dislocation pit densities using a QTM-720 Quantitative Image Analyzing system. The QTM-720 system was upgraded with the addition of a PDP 11/03 mini-computer with dual floppy disc drive, a digital equipment writer high speed printer, and a field-image feature interface module. Three versions of a computer program that controls the data acquisition and analysis on the QTM-720 were written. Procedures for the chemical polishing and etching were also developed

CLIMATE CHANGE INFLUENCES ON THE RISK OF AVIAN INFLUENZA OUTBREAKS AND ASSOCIATED ECONOMIC LOSS

This paper examines the effect that climate has on Avian Influenza outbreak probability. The statistical analysis shows across a broad region the probability of an outbreak declines by 0.22% when the temperature rises 1 Celsius degree and increases by 0.34% when precipitation increases by 1millimeter. These results indicate that the realized climate change of the last 20 years not only has been a factor behind recent HPAI outbreaks, but that climate change is likely to play an even greater role in the future. The statistical results indicate that overall, the risk of an AI outbreak has been increased by 51% under past climate change and 3-4% under future climate change. An economic evaluation shows the increased probability of outbreaks has caused damages of about $107 million in China and$29 million in the United States due to past climate change. In the year of 2011-2030, for countries with a high proportion of chicken production, economic loss could reach $105-$146 million in China and $12-$18 million in the United Sates.Climate change, Avian Influenza outbreaks, GDP loss, Environmental Economics and Policy, Research Methods/ Statistical Methods,

A quantum Peierls-Nabarro barrier

Kink dynamics in spatially discrete nonlinear Klein-Gordon systems is considered. For special choices of the substrate potential, such systems support continuous translation orbits of static kinks with no (classical) Peierls-Nabarro barrier. It is shown that these kinks experience, nevertheless, a lattice-periodic confining potential, due to purely quantum effects anaolgous to the Casimir effect of quantum field theory. The resulting ``quantum Peierls-Nabarro potential'' may be calculated in the weak coupling approximation by a simple and computationally cheap numerical algorithm, which is applied, for purposes of illustration, to a certain two-parameter family of substrates.Comment: 13 pages LaTeX, 7 figure