ESTIMATION OF FIRM-VARYING, INPUT-SPECIFIC EFFICIENCIES IN DAIRY PRODUCTION

Firm-varying production technologies were estimated using random coefficients regression methods for a sample of Massachusetts dairy farms. Results were compared to OLS Cobb-Douglas production function estimates. The random coefficients regression model was found to virtually eliminate conventionally measured firm technical inefficiencies by estimating individual firm technologies and ascribing remaining inefficiencies to specific inputs. Input-specific measures of firm inefficiencies showed hired labor, land, and machinery inputs to be used in excess of efficient levels. Livestock supplies were underutilized by all farms. Efficiencies of feed, crop materials, fuels, and utilities varied, although estimated means were closer to optimal levels.Production Economics,

IMPACTS OF THE NORTHEAST DAIRY COMPACT ON NEW ENGLAND RETAIL PRICES

Northeast Dairy Compact impacts were estimated for Boston and Hartford retail prices using an econometric model. Asymmetric speeds of adjustment to farm price increases and decreases were found; however, tests indicated that retail prices do return to the same level following equal farm price increases and decreases. Model forecasts suggested no structural changes occurred during the out-of-sample period, July 1996 through June 1998. Simulations with and without the Compact predicted lower retail fluid milk price impacts than actual July 1997 changes. These predicted impacts separate the effects of farm price changes on retail prices from possibly confounding effects.Demand and Price Analysis,

IMPACTS OF THE NORTHEAST INTERSTATE DAIRY COMPACT ON SUPPLY, RETAIL PRICES AND THE WIC PROGRAM: AN INTRODUCTION

Demand and Price Analysis, Food Security and Poverty,

STOCHASTIC EFFICIENCY ANALYSIS OF COMMUNITY-SUPPORTED AGRICULTURE CORE MANAGEMENT OPTIONS

The continued decline in both the number of and the acreage in small-scale farms and rural communities, as well as food safety and environmental concerns, has heightened interest in the community-supported agriculture (CSA) concept. Mean-variance, stochastic dominance, mean-Gini, and exponential utility/moment-generating function approaches to stochastic efficiency are employed to analyze three years of farm survey data on core management options for CSA farms. The core concept yields higher net income per acre than non-core management and, based on the stochastic efficiency analysis, should be regarded as the preferred management option for many CSA operators.Agribusiness,

Market Power in Direct Marketing of Fresh Produce: Community Supported Agriculture Farms

CSA farms establish a loyal customer base and, potentially, market power. A new empirical industrial organization (NEIO) approach and survey data from Northeast CSA farms are used to determine whether CSA farms have market power and the extent to which they exercise their market power. Results suggest CSA farms exert about two percent of their potential monopoly power.Community Supported Agriculture; New Empirical Industrial Organization; Market Power; Fresh Produce; Organic Agriculture

OFF-FARM EMPLOYMENT DECISIONS BY MASSACHUSETTS FARM HOUSEHOLDS

The off-farm labor participation and supply decisions of Massachusetts farm families were estimated in a model which allows for joint decisions. The hypothesis of joint off-farm participation decisions by operators and spouses was rejected. However, there was some evidence that the hours supplied by the farm operator was dependent upon the decision by the spouse to work off-farm. Farm operators were found to respond to both family and farm characteristics in making participation and supply decisions. Spouses respond to the characteristics of the farm and family in participation decisions while family characteristics determined hours worked by the spouse.Consumer/Household Economics,

Reactive Oxygen Species Production by Forward and Reverse Electron Fluxes in the Mitochondrial Respiratory Chain

Reactive oxygen species (ROS) produced in the mitochondrial respiratory chain (RC) are primary signals that modulate cellular adaptation to environment, and are also destructive factors that damage cells under the conditions of hypoxia/reoxygenation relevant for various systemic diseases or transplantation. The important role of ROS in cell survival requires detailed investigation of mechanism and determinants of ROS production. To perform such an investigation we extended our rule-based model of complex III in order to account for electron transport in the whole RC coupled to proton translocation, transmembrane electrochemical potential generation, TCA cycle reactions, and substrate transport to mitochondria. It fits respiratory electron fluxes measured in rat brain mitochondria fueled by succinate or pyruvate and malate, and the dynamics of NAD+ reduction by reverse electron transport from succinate through complex I. The fitting of measured characteristics gave an insight into the mechanism of underlying processes governing the formation of free radicals that can transfer an unpaired electron to oxygen-producing superoxide and thus can initiate the generation of ROS. Our analysis revealed an association of ROS production with levels of specific radicals of individual electron transporters and their combinations in species of complexes I and III. It was found that the phenomenon of bistability, revealed previously as a property of complex III, remains valid for the whole RC. The conditions for switching to a state with a high content of free radicals in complex III were predicted based on theoretical analysis and were confirmed experimentally. These findings provide a new insight into the mechanisms of ROS production in RC

A guideline for placement of an infra-acetabular screw based on anatomic landmarks via an intra-pelvic approach

Background: Due to demographic changes, more and more fracture patterns involving anterior acetabular structures occur. The infra-acetabular screw is seen a useful tool to increase stability in fixation of the acetabular cup. However, the exact position of this screw in relation to anatomic landmarks which are intra-operatively palpable via an intra-pelvic approach has not yet been determined. Methods: This biomorphometric experimental study references the ideal screw position of an infra-acetabular screw to anatomic landmarks palpable via an intra-pelvic approach. Therefore, we created a computer tomography-based 3D-model of 40 patients (20 women, 20 men) who received a computer tomography (CT) scan of the pelvis for any other reason than an acetabular fracture. Results: The entry point of an ideal infra-acetabular was of high constancy. At mean, this point was 10.2 mm caudal and 10.4 mm medial of the ilio-pubic/ilio-pectineal eminence. This reference is independent of age, gender, or physical dimensions. However, we found gender-dependent differences for the angulation and the length of the screw. Conclusions: This study provides a comprehensive guideline to determine the ideal entry point for an infra-acetabular screw via an intra-pelvic approach. The entry point is located 10.2 mm caudal and 10.4 mm medial of the ilio-pubic/ilio-pectineal eminence