COMMODITY PROGRAM SLIPPAGE RATES FOR CORN AND WHEAT

Slippage rates for corn and wheat are estimated using a simultaneous system explaining per-acre yields, input usage, technical change, and levels of participation in government programs. Soybeans are included due to cross-compliance requirements and because they substitute for corn in production. Slippage rates for wheat are in the range of 29-37% and for corn in the range of 48-58%. The results imply that efficient design of commodity programs must account for the slippage of aggregate yields due to changes in land quality and the use of constrained resources over fewer acres.Crop Production/Industries,

DCU at the TREC 2008 Blog Track

In this paper we describe our system, experiments and re- sults from our participation in the Blog Track at TREC 2008. Dublin City University participated in the adhoc re- trieval, opinion finding and polarised opinion finding tasks. For opinion finding, we used a fusion of approaches based on lexicon features, surface features and syntactic features. Our experiments evaluated the relative usefulness of each of the feature sets and achieved a significant improvement on the baseline

Standardized Testing: Are the Benefits Really there?

The proponents of standardized high-stakes testing argue that this type of assessment will and does promote increased knowledge acquisition by students. The opponents of this testing claim any apparent knowledge increase as measured by improvements in tests scores are mainly due to teaching to the test. This study was done to determine whether high-stakes testing does in fact improve the knowledge of the students. Data from two national college entrance examinations were collected and reviewed changes over time as reference to knowledge improvements. Test scores from three state high-stakes tests were collected (California, Texas, and Colorado). The scores from the national tests both the national averages (composite scores) and the individual state averages were tabulated and plotted. The relative change over time was determined for the national examinations and the state examinations. The results of this study call into question the hypothesis that high-stakes testing improves results of education. The national examinations improved at approximately the same rate for the period examined (12-14 years) while the state test scores show greater changes either positively or negatively for the final 5-6 years examined. One conclusion that can be drawn by that is that the state test scores improved based on changes in what is being taught in the classroom, i.e. teaching to the test. The conclusion of this work is that the hypothesis that high-stakes testing will improve the knowledge of student must be rejected. Because of that the use and value of high-stakes testing is called into question and should be reevaluated and if not just eliminated then these tests need to be revised both in content and emphasis

THE IMMUNE RESPONSES OF CARP, CYPRINUS CARPIO L., FOLLOWING DIRECT IMMERSION IMMUNIZATION

The investigations presented in this thesis include studies on a) the immune responses of carp following direct immersion immunization and subsequent intraperitoneal (i.p.) challenge, b) the uptake and accumulation in carp of a direct immersion vaccine and c) phagocytic uptake by carp peritoneal exudate cells (PECs). To assess the cell-mediated immune response of carp, a micro chemotaxis technique was developed, measuring the production of chemotactic factor-like activity in supernatants from incubations of pronephric cells with antigen. In no case were serum antibody titres or a cell-mediated immune response detectable after immersions alone in antigen. It was found that an i.p. challenge of antigen in adjuvant, subsequent to the immersions, was needed to stimulate a measurable response, with effective priming immersions stimulating a secondary response to the i.p. challenge. It was found that the opsonization of both soluble and particulate immersion vaccines with immune carp serum significantly increased the immunological memory for both the humoral and the cell-mediated immune responses following immersion. Opsonization of the vaccines with normal serum, however, had no detectable effect. The cell-mediated immune responses following immersion were only measured in immunologically mature carp, but the humoral immune responses were measured in both immunologically mature and immature carp, which were 4 weeks old at the beginning of the experiments. Using the bacterial Aeromonas salmonicida antigen, all the responses measured post-immersion were found to be positive in both immunologically mature and immature carp. However, with the T-dependent antigen, human gamma globulin (HGG), the immune responses post-immersion were found to be positive only in the immunologically mature fish, with immersion of the immature carp in HGG-coated latex particles opsonized with immune serum producing a tolerizing effect on the humoral immune response. There was no detectable uptake of a non-opsonized A.salmonicida vaccine in normal carp when immersed in a bath of the vaccine. However, if the vaccine was opsonized with immune carp serum, uptake and accumulation of the vaccine was detectable, mostly accumulating in the internal lymphoid organs. Uptake of the non-opsonized vaccine was, however, also found when the recipient carp had been previously immunized against A.salmonicida, by immersion. The phagocytic uptake of particles by carp PECs was also found to be enhanced by opsonization of the particles with immune carp serum, this effect being partially recuced by decomplementation of the opsonizing serum. Opsonizat1on of particles with normal serum was found to have no effect on phagocytic uptake. Immersions in several different sizes of latex particles (from O.O5 µm to l5 µ.m) coated with HGG were found to stimulate greater humoral immunological memory than immersions in soluble HGG. This was not the case for memory for the cell-mediated response, where immersions in latex particle-bound HGG were no more stimulatory than immersions in soluble HGG. Carp PECs were found to be able to ingest 0.8 µm and 3.0 µm diameter particles but uptake of I5 µm diameter particles was not observed. The specificity of the humoral immune response after direct immersion immunization was found to be high with no cross-reactivity with any of the other antigens used. The cell-mediated immune response following direct immersion immunization was found to be slightly less specific; cross-reactivity between HGG and chicken gamma globulin was detected, although the other antigens used showed no cross-reactivity.Kingston Polytechnic, London, U.K

Radiolysis of saturated aqueous iodine solutions

It is a well-known fact that water, when subjected to ionizing radiation such as x-ray or gamma radiation, undergoes a decomposition. The generally accepted decomposition, although complex, may be represented by (1): It is also accepted that when dilate solutions are irradiated, practically all the energy absorbed is deposited in water molecules and the observed chemical changes are brought about indirectly via the molecular and, particularly, the radical products. Direct action due to energy deposited in the solute is generally unimportant in dilute solutions (i.e at solute concentration below about 0.1M)” (3). Realizing that iodine is an excellent radical scavenger (3), and can undergo several reactions with primary and secondary products, it is not unreasonable to expect some change in the iodine concentration of a saturated aqueous iodine solution upon exposure to ionizing radiation. The problem investigated, was the effect of Co - 60 gamma radiation on saturated aqueous solutions of iodine

The use of CFD for predicting buoyant and forced convection flows occurring in food refrigeration

Being able to maintain the temperature of food is of vital importance to ensure optimal food quality, safety and shelf life. Most unwrapped food and all types of wrapped foods are stored in large refrigerated rooms with forced air circulation. A reduction in the average storage temperature can significantly increase the length of retention and quality of many chilled foods. Air infiltration through entrances can account for more than half the total heat load for refrigerated stores.Chilled foods are often transported to supermarkets where they are then displayed in open fronted refrigerated display cabinets. These cabinets are one of the weakest links in the chilled food chain with large temperature ranges between products in the same cabinet. This range in temperature causes problems for food manufacturers when defining shelf life and results in shelf lives that are either unduly cautious or potentially risky.The aim of this thesis was to use CFD to solve problems encountered in the food/refrigeration industry. It describes the use of CFD for two separate problems (cold store door opening and open fronted refrigerated display cabinets) which are caused by the same physical phenomena (natural convection between air at different temperatures).CFD predictions of unprotected entrances give a significant improvement in accuracy over the fundamental analytical equations. Factors such as the extent of the ambient domain that needs to be modelled are an important consideration in gaining accurate predictions. A 2D CFD model was able to predict the effectiveness of an air curtain; however, the predictions were higher than measured. A 3D CFD model was able to provide a better prediction of effectiveness and optimum jet velocity than the 2D model. This thesis highlights the importance of setting up a cold store air curtain properly, if it is to work at its optimum efficiency

The matching law

This article introduces the quantitative analysis of choice behavior by describing a number of equations developed over the years to describe the relation between the allocation of behavior under concurrent schedules of reinforcement and the consequences received for alternative responses. Direct proportionality between rate of responding and rate of reinforcement was observed in early studies, suggesting that behavioral output matched environmental input in a mathematical sense. This relation is termed "strict matching," and the equation that describes it is referred to as "the matching law." Later data showed systematic departures from strict matching, and a generalized version of the matching equation is now used to describe such data. This equation, referred to as "the generalized matching equation," also describes data that follow strict matching. It has become convention to refer to either of these equations as "the matching law." Empirical support for the matching law is briefly summarized, as is the applied and practical significance of matching analyses