High Performance Associative Memories and Structured Weight Dilution

Copyright SpringerThe consequences of two techniques for symmetrically diluting the weights of the standard Hopfield architecture associative memory model, trained using a non-Hebbian learning rule, are examined. This paper reports experimental investigations into the effect of dilution on factors such as: pattern stability and attractor performance. It is concluded that these networks maintain a reasonable level of performance at fairly high dilution rates

The Influence of Agro-Terrorism on Consumer Buying Behavior: An Analysis Based on New Jersey Consumers

Consumer/Household Economics, Food Consumption/Nutrition/Food Safety,

Potential Impact of Agro-terrorism Perceptions on Demand for Locally Grown Products

The economics of agroterrorism has not been fully developed within the economics literature, yet with increasing concerns about agroterrorism it is important to understand how consumers will generally respond. This paper presents an overview of food safety issues, and develops an economical model that can be used to illustrate and establish hypotheses regarding consumer behavior and agroterrorism. We then present sample and econometric results from a survey of 304 New Jersey consumers and explain the characteristics of the 33% that confirmed that they have increased purchases of locally grown produce due to terrorism fears.Agribusiness, Demand and Price Analysis,

Historical data as a baseline for conservation: reconstructing long-term faunal extinction dynamics in Late Imperial–modern China

Extinction events typically represent extended processes of decline that cannot be reconstructed using short-term studies. Long-term archives are necessary to determine past baselines and the extent of human-caused biodiversity change, but the capacity of historical datasets to provide predictive power for conservation must be assessed within a robust analytical framework. Local Chinese gazetteers represent a >400-year country-level dataset containing abundant information on past environmental conditions and include extensive records of gibbons, which have a restricted present-day distribution but formerly occurred across much of China. Gibbons show pre-twentieth century range contraction, with significant fragmentation by the mid-eighteenth century and population loss escalating in the late nineteenth century. Isolated gibbon populations persisted for ~40 years before local extinction. Populations persisted for longer at higher elevations, and disappeared earlier from northern and eastern regions, with the biogeography of population loss consistent with the contagion model of range collapse in response to human demographic expansion spreading directionally across China. The long-term Chinese historical record can track extinction events and human interactions with the environment across much longer timescales than are usually addressed in ecology, contributing novel baselines for conservation and an increased understanding of extinction dynamics and species vulnerability or resilience to human pressures

Integrating ecology into macroevolutionary research

On 9 March, over 150 biologists gathered in London for the Centre for Ecology and Evolution spring symposium, ‘Integrating Ecology into Macroevolutionary Research’. The event brought together researchers from London-based institutions alongside others from across the UK, Europe and North America for a day of talks. The meeting highlighted methodological advances and recent analyses of exemplar datasets focusing on the exploration of the role of ecological processes in shaping macroevolutionary patterns

Deep MOS Spectroscopy of NGC 1316 Globular Clusters

The giant elliptical galaxy NGC 1316 is the brightest galaxy in the Fornax cluster, and displays a number of morphological features that might be interpreted as an intermediate age merger remanent ($\sim$3 Gyr). Based on the idea that globular clusters systems (GCS) constitute genuine tracers of the formation and evolution of their host galaxies, we conducted a spectroscopic study of approximately 40 globular clusters (GCs) candidates associated with this interesting galaxy. We determined ages, metallicities, and $\alpha$-element abundances for each GC present in the sample, through the measurement of different Lick indices and their subsequent comparison with simple stellar populations models (SSPs).Comment: 5 pages, 3 figure

Returns to the Jersey Fresh Promotional Program: The Impacts of Promotional Expenditures on Farm Cash Receipts in New Jersey

In 1984, the Jersey Fresh program was implemented by the New Jersey Department of Agriculture and was the first state-funded marketing campaign for agricultural products produced in New Jersey. In an effort to spur demand for New Jersey farm products, this program was designed to increase consumer awareness of the state’s agricultural products as well as to encourage food retailers to promote Jersey Fresh products. With funding from the USDA’s Federal-State Marketing Improvement Program, the New Jersey Department of Agriculture commissioned this study to determine the impact of Jersey Fresh promotion on farmer cash receipts in New Jersey. The econometric analysis was focused on the fruit and vegetable sectors, the primary commodity areas expected to benefit most directly from Jersey Fresh promotion. Study results show that: • For every dollar spent on the Jersey Fresh Promotional Program through 2000, New Jersey’s agricultural fruit and vegetable sector revenues increased by $31.54 (2003 dollars). • The additional economic activity created in the agricultural industry also had impacts on other parts of the economy, namely agricultural suppliers and service providers. In fact, each dollar spent on Jersey Fresh promotion resulted in an additional$22.95 of sales in agricultural support industries and other related industries. • In total, each dollar spent on Jersey Fresh promotion resulted in $54.49 of increased economic output in the State. Adjusting all dollars to 2003 levels, this means that the$1.16 million spent on the Jersey Fresh program in 2000 increased fruit and vegetable cash receipts by $36.6 million and created an additional$26.6 million in economic activity within agricultural support industries. The total statewide economic impact of the Jersey Fresh program was therefore an estimated $63.2 million. The economic activity generated through Jersey Fresh promotion also impacts local, state, and federal taxes. An analysis of these tax impacts shows that New Jersey’s State and local tax revenues increased by$2.2 million in 2000 due to the increased economic activity attributable to Jersey Fresh promotion. Comparing this return to the 2000 program budget of $1.16 million, the Jersey Fresh program appears to be better than revenue-neutral.Agribusiness, Marketing,

The performance of index based livestock insurance: ex ante assessment in the presence of a poverty trap

This paper evaluates the effectiveness of a new index-based livestock insurance (IBLI) product designed to compensate for area average predicted livestock mortality loss in northern Kenya, where previous work has established the presence of poverty traps. We simulate household-specific wealth dynamics based on a model parameterized using rich panel and experimental data from the region. The simulations allow us to investigate patterns of willingness to pay for asset index insurance that is imperfectly correlated with individuals' loss experience. The bifurcated livestock dynamics associated with the poverty trap gives rise to insurance valuation that is highly nonlinear in individual herd size. Willingness to pay among vulnerable groups who most need insurance are, on average, lower than commercially viable rates but subsidization of IBLI premiums appears to offer more cost-effective poverty reduction than direct transfers to the poor

The past and future human impact on mammalian diversity

To understand the current biodiversity crisis, it is crucial to determine how humans have affected biodiversity in the past. However, the extent of human involvement in species extinctions from the Late Pleistocene onward remains contentious. Here, we apply Bayesian models to the fossil record to estimate how mammalian extinction rates have changed over the past 126,000 years, inferring specific times of rate increases. We specifically test the hypothesis of human-caused extinctions by using posterior predictive methods. We find that human population size is able to predict past extinctions with 96% accuracy. Predictors based on past climate, in contrast, perform no better than expected by chance, suggesting that climate had a negligible impact on global mammal extinctions. Based on current trends, we predict for the near future a rate escalation of unprecedented magnitude. Our results provide a comprehensive assessment of the human impact on past and predicted future extinctions of mammals