Studies on the interactions between larval stages of digenetic flukes and their molluscan hosts

Snails of the species Thais (Nucella) lapillus (L) were collected from Scarborough South Bay, and Robin Hoods Bay, North Yorkshire. The presence of the rediae of Parorchia acanthus NICOLL (Digenea: PHILOPHTHALMIDAE) in T.lapillus individuals was previously associated with abnormal shell growth by Feare (1970a). His work has been extended to provide more conclusive evidence of parasitic gigantism in T.lapillus infested with P.acanthus. The energy increment and soft tissue mass increase associated with shell growth has been calculated for a sample of infested T.lapillus individuals. As reported by Cooley (1958) and Feare (1969) infestation with P.acanthus rediae progressively destroys the host gonad. The resultant reproductive saving was estimated for non-infested male and female T.lapillus from Robin Hoods Bay in 1981 and the energy values obtained were compared with estimates of the average energy loss from infested T. lapillus as a result of cercarial production and redial growth. The proportion of the whole body dry mass of infested T. lapillus individuals contributed by the redial population was generally similar to the gonadal proportion of non-infested femalest but did not follow the same seasonal cycle. The digestive gland of infested dogwhelks was proportionally reduced from that of non-infested females in August only. The growth of redial populations within the hosts through the summer is suggested as a possible cause of host gigantism. The relative advantages to the parasite of selecting female hosts are also discussed

Inverted Sugar: Generalized Ray Tracing Algorithm

Though particular algorithms utilizing Snell’s Law effectively describe most ray tracing, issues arise with infrasound applications, particularly in understanding waveguides. A more generalized differential equation derived from Fermat’s principle of least time and general functions may provide a computational solution to coupling ray tracing with wavelength related issues. However, due to its complexity, this differential equation deserves its own experimentation to confirm or deny its effectiveness. In this experiment, a gradient of index of refraction established by the diffusion of sugar emulated an atmospheric temperature inversion (hence “Inverted Sugar”) and comparison of actual rays to computer generated rays in the same gradient confirmed the accuracy of this algorithm

The Sketching Complexity of Graph and Hypergraph Counting

Subgraph counting is a fundamental primitive in graph processing, with applications in social network analysis (e.g., estimating the clustering coefficient of a graph), database processing and other areas. The space complexity of subgraph counting has been studied extensively in the literature, but many natural settings are still not well understood. In this paper we revisit the subgraph (and hypergraph) counting problem in the sketching model, where the algorithm's state as it processes a stream of updates to the graph is a linear function of the stream. This model has recently received a lot of attention in the literature, and has become a standard model for solving dynamic graph streaming problems. In this paper we give a tight bound on the sketching complexity of counting the number of occurrences of a small subgraph $H$ in a bounded degree graph $G$ presented as a stream of edge updates. Specifically, we show that the space complexity of the problem is governed by the fractional vertex cover number of the graph $H$. Our subgraph counting algorithm implements a natural vertex sampling approach, with sampling probabilities governed by the vertex cover of $H$. Our main technical contribution lies in a new set of Fourier analytic tools that we develop to analyze multiplayer communication protocols in the simultaneous communication model, allowing us to prove a tight lower bound. We believe that our techniques are likely to find applications in other settings. Besides giving tight bounds for all graphs $H$, both our algorithm and lower bounds extend to the hypergraph setting, albeit with some loss in space complexity

Immigrant Job Search in the UK

Most immigrant groups in the UK experience higher unemployment rates than otherwise similar UK born whites. Empirical research to date has attributed this finding to discrimination, lack of English Language fluency and the (non-) transferability of skills acquired before immigration. In this paper, we investigate how the job search methods of unemployed white and ethnic minority immigrants, and their success in exiting unemployment, compare with the UK born, using the panel element of the Quarterly Labour Force Survey, pooled over 1997-2001. We condition, amongst other things, on some observable immigrant characteristics and discuss the policy implications of our findings.unemployment, job search, immigrants

INCREASING FOOD RECOVERY FROM FARMERS' MARKETS: A PRELIMINARY ANALYSIS

Collecting unsold food discarded at farmer's markets has the potential to allow nonprofit food recovery and gleaning organizations to distribute significant quantities of wholesome, unsold fruits and vegetables to needy families. Donations of this unsold produce by the participants at these markets can generate tangible benefits: increased private food assistance and better nutrition for lower income families. The Geographical Information System (GIS) analysis presented in this study indicates that there is potential to strengthen the links between farmer's markets and nonprofit food recovery and gleaning organizations in many areas of the United States.Food Consumption/Nutrition/Food Safety, Marketing,

IMPLICATIONS OF RAISING THE NONFAT SOLIDS STANDARDS FOR BEVERAGE MILK

An econometric model of the dairy industry was used to estimate the effects on farmers, consumers, and taxpayers of nationwide adoption of the California nonfat solids standards for fluid milk. It was estimated that adoption of the California standards would raise farm-level milk prices by 1 to 5 percent in the short run and by 1 to 2 percent in the long run. The average retail price of fluid milk would rise by 9 to 13 cents per gallon. Dairy program costs fall under most scenarios, but could rise if surpluses fall to levels that would trigger increases in the support price.Agricultural and Food Policy,

ANALYSIS OF THE U.S. COMMODITY LOAN PROGRAM WITH MARKETING LOAN PROVISIONS

Over the next several years, crop prices are projected to be below to slightly above commodity loan rates. As a result, marketing loan benefits to farmers, in the form of loan deficiency payments and marketing loan gains from the commodity loan program, are likely to continue to be sizeable. The level of realized per-unit revenues facilitated by marketing loans exceeds commodity loan rates, thereby raising expected net returns to farmers. Model simulations show that the loan program can raise total acreage planted to major field crops, generally increasing levels of domestic use and exports while lowering crop prices. Cross-commodity effects of supply response to relative returns (including marketing loan benefits), however, result in acreage shifts among competing crops, which can lead to reductions in plantings of some crops in some years. Most impacts occur in the years when there are marketing loan benefits, with little effect in subsequent years when prices rise high enough to eliminate marketing loan benefits. The livestock sector benefits from these outcomes because of generally lower feed costs.Commodity loans, marketing loans, nonrecourse loans, loan deficiency payments, price support, commodity programs, Agricultural Finance,