ENGAGING STUDENTS IN RESEARCH: THE USE OF STRUCTURED PROFESSIONAL DIALOGUE

Graduate students frequently have difficulty defining, developing, and resolving research problems in a manner consistent with the agricultural economics community. Here, we report on a seminar designed to assist graduate students integrate subject matter courses into independent research proposals through participation in professional dialogue. Professional dialogue involves developing arguments to explain and resolve questions where the explanations are supported by warranted evidence and appropriately qualified. The premise of the seminar is that more active problem solvers are developed using professional dialogue to sharpen critical thinking and writing skills.Teaching/Communication/Extension/Profession,

OPTIMAL RISK MANAGEMENT, RISK AVERSION, AND PRODUCTION FUNCTION PROPERTIES

For production risk with identified physical causes, the nature of risk, production characteristics, risk preference, and prices determine optimal input use. Here, a two-way classification for pairs of inputs – each input as being risk increasing or decreasing and pairs as being risk substitutes or complements – provides sufficient conditions to determine how risk aversion should affect input use. Unlike the Sandmo price risk averse firm may produce more expected output and use more inputs than a risk neutral firm. Sufficient conditions to determine types for pairs of inputs are also related to properties of the production function.Production Economics, Risk and Uncertainty,

Is Foreign Aid Beneficial for Sub-Saharan Africa? A Panel Data Analysis

Significant ambiguity surrounds the magnitude and sign of the effect of foreign aid on economic growth. Foreign aid can potentially augment scarce domestic capital to spur growth but foreign aid can also remove positive incentive to build wealth, stalling growth. This paper characterizes the effect of foreign aid on the growth of Sub-Saharan African countries after correcting endogeneity problems that plague the estimation. Foreign aid is found to be growth promoting given good governance and using fixed effects in a static panel framework. Data from twenty-one Sub-Saharan African countries spanning 1995-2003 was used in the estimation. The finding of a significant foreign aid-growth relationship is pertinent because it suggests that increased aid to Sub Saharan Africa is one way to achieve the UN’s Millennium goals. By lobbying for increased foreign aid, advocates are prescribing a necessary albeit insufficient medicine for Sub Saharan Africa’s economic problems.Food Security and Poverty,

Genetically Modified Crops and Labor Savings in US Crop Production

In spite of widespread adoption there is mixed evidence as to whether or not adopting Genetically Modified (GM) crops increase farm welfare. One possible reason for widespread adoption is labor savings. Using a treatment effect model we estimate the labor savings associated with adopting a GM crop.genetically modified crops, agricultural biotechnology, endogeneity, treatment effects, survey weights, Crop Production/Industries,

FARM FINANCIAL STRUCTURE DECISIONS UNDER DIFFERENT INTERTEMPORAL RISK BEHAVIORAL CONSTRUCTS

An alternative unconstrained expected-utility maximization model of farm debt is developed using the location-scale parameter condition that incorporates the empirically validated hypotheses of decreasing absolute and constant relative risk aversion. Simulation-optimization results based on the old and new model versions provide interesting implications for various levels of risk aversion and initial equity investments.Risk and Uncertainty,

AN EXAMINATION OF THE STABILITY OF COOPERATION IN A VOLUNTARY COLLECTIVE ACTION: THE CASE OF NONPOINT-SOURCE POLLUTION IN AN AGRICULTURAL WATERSHED

This paper addresses the collective action problem of nonpoint-source pollution control in a small agricultural watershed. At issue is the stability of cooperative behavior among a group of farmers, who have voluntarily agreed to discontinue their use of the herbicide atrazine due to high concentrations of the herbicide in a local water supply. Continued cooperation among the group is threatened by the unexpected cancellation of cyanazine, an inexpensive and widely used alternative to atrazine. With cyanazine no longer available, the farmers will face a significant increase in weed control costs if they continue to use products that do not contain atrazine. Is cooperation among the farmers still possible despite the increased cost of cooperating? This research explores the economic and behavioral factors that influence the collective outcome of this social dilemma. The collective action is modeled as a recurrent coordination problem. The producers (farmers) are engaged in a repeated assurance game with imperfect public information, where producers' choices are driven by the desire to coordinate their actions with the others in the group. A producer's decision to cooperate or defect is based on a threshold approach; if the number of others believed to be cooperating exceeds the level of cooperation required to make cooperation beneficial, then the producer will choose to cooperate. Otherwise, the producer will defect. Since producers are unable to directly observe the choices of the others in the group, each producer must rely on a subjective assessment of the group's behavior based on the realization of the public outcome, the concentration of atrazine in the lake. Producers use a naive Bayesian learning process to update their beliefs about the joint actions of the group. The formal learning process is modeled using a sequential quasi-Bayesian procedure that is consistent with the fictitious play model of learning. The interaction between the producers and the impact of their collective behavior on the levels of atrazine in the lake is formulated as a computational multi-agent system (MAS). The MAS is an artificial representation of the collective action problem that integrates the economic, behavioral and environmental factors that influence the decision-making process of producers. The MAS is used to simulate the evolution of collective behavior among the group and to evaluate the effectiveness of selected incentive mechanisms in preventing the collapse of joint cooperation. The results suggest that without additional incentives, farmers are likely to abandon their voluntary agreement and resume their use of atrazine within the watershed. It is then demonstrated how a combination of policy instruments can be used to alter the underlying game configuration of the collective action problem, resulting in cooperative outcomes. An ambient-based penalty, when used in conjunction with a subsidy payment, is shown to produce divergent incentive structures that shift the classification of the collective action away from a coordination problem with two equilibria to a mixed configuration containing several different game structures and many possible equilibria. This result has important consequences in terms of the evolution of producer behavior and the set of possible collective outcomes. The analysis concludes with an example, which demonstrates that when a mixture of game structures characterizes the collective action, joint cooperation is not a prerequisite to the realization of socially desirable outcomes. By carefully selecting the combination of subsidy payment and ambient penalty, a policy maker can manipulate the underlying structure of the collective action, whereby producers with the smallest impact on water quality choose to defect while all others cooperate.Environmental Economics and Policy,

DETERMINANTS OF THE VALUE OF SITE-SPECIFIC INFORMATION (SSI) IN AGRICULTURE: A UNIFYING THEORY TO ANALYZE ITS RELATIVE IMPACTS

This paper develops a theoretically consistent behavioral model of farmer decision-making that allows for analysis of the relative impacts of the determinants of SSI value. The model departs from previous literature by assuming that SSI reduces uncertainty, but not eliminate it. Results show that increasing the accuracy (or the "level of informativeness") of SSI, increasing initial wealth, improving management ability to reduce uncertainty in the posterior, and increasing the uncertainty in the prior, increases the value of SSI. Furthermore, mean input use is found to decrease, as SSI becomes more "informative." On the other hand, the value of SSI is found to be decreasing as relative risk aversion increases. These results have policy implications for controlling non-point source pollution from fertilizer inputs and SSI-adoption behavior.Farm Management, Research Methods/ Statistical Methods,

Acute atomic radiation injury: its physiological and biochemical pathogenesis with a note on therapy

Thesis (M.D.)—Boston UniversityThis paper deals with the fundamental mechanisms through which atomic radiation injures living cells aDd thereby injures the human organism. No attempt has been mde to leal exhaustively with aey one point; rather the attempt has been to present a broad orientation within the field and then to present sufficient data to allow the formulation of the most reasonable hypothesis which will account for the changes observed in radiation injury. The material selected for presentation and discussion has been chosen from the work of researchers who seem to have contributed data or hypotheses which appear fundamental to the concept of radiation injury

MODULAR CABLE - DRIVEN SURGICAL ROBOTS

A surgical robot can be configured for minimally invasive surgery ( MIS ) and other types of surgery with modular link geometry and disposable components. In some examples, the surgical robot includes a cable driver comprising at least one drive motor configured for tensioning a cable. The surgical robot includes an articulated surgical tool coupled to the drive motor by the cable. The articulated surgical tool comprises at least first and second articulated links and a joint coupling the first and second articulated links. The cable passes through the joint, and the joint comprises an elastic antagonist biased in opposition to tension from the cable to allow bidirectional actuation of the joint. The surgical robot includes a safety lock configured to lock the joint from allowing articulation of the first and second articulated links in response to a loss of tension in the cable

Investigation of uranium oxide of low oxidation state

Thesis (B.S.)--Massachusetts Institute of Technology, Dept. of Chemistry, 1957.MIT copy bound with: Use of radioactive tracers in following rare earth separations carried out by homogeneous precipitation / John Scott Mudgett. 1957.Includes bibliographical references (leaf 14).by Carl W. Nelson.B.S