Theme Overview: Addressing the Obesity Challenge

obesity, BMI, nutrition, food choices, Food Consumption/Nutrition/Food Safety, I1, Q1,

A MODEL OF IMPERFECT COMPETITION USING MARGINAL INPUT AND OUTPUT PRICES: APPLICATION TO THE BEEF PACKING INDUSTRY

Based on Diewert's idea that models under competition can be generalized to imperfect competition using marginal prices, we develop a test for imperfect competition in the beef packing industry. Our model is more general and flexible than those depending on empricial estimates of the input supply and output demand elasticities.Agribusiness, Demand and Price Analysis,

MEASURING THE DEGREE OF OLIGOPSONY POWER IN THE BEEF PACKING INDUSTRY IN THE ABSENCE OF MARKETING INPUT QUANTITY DATA

We develop a model to measure the degree of oligopsony power in the beef packing industry, while accommodating variable proportions technology, that can be estimated with fewer data requirements. In particular, nonspecialized input quantities, which are often not available, are not needed. Through application of the envelope theorem, we show that the relationship between value marginal product and marginal factor cost can be defined over the prices of the nonspecialized inputs rather than their corresponding quantities. When applied to the beef packing industry, we find no evidence of oligopsony power over our 1967-93 sample period.Agribusiness,

Analysis of the Economic Effects of Requiring Post-harvest Processing for Raw Oysters

oysters, post-harvest processing, hydrostatic pressure, cool pasteurization, GIS, Agricultural and Food Policy, Food Consumption/Nutrition/Food Safety, L510, Q180, Q220,

EXIT OF MEAT SLAUGHTER PLANTS DURING IMPLEMENTATION OF THE PR/HACCP REGULATIONS

Implementation of the Pathogen Reduction and Hazard Analysis and Critical Control Points (PR/HACCP) regulations has occurred across all U.S. meat and poultry plants. A probit model is estimated to determine which factors have affected the probability of red meat slaughter plant exit during implementation of the regulations. While controlling for plant-level, company-level, regional-level, and supply conditions that may affect the probability of plant exit, smaller plants are found to exhibit a much greater probability of exit than larger plants. Other factors affecting plant exit include plant age, market share relative to the degree of market concentration, regional entry rates, and state-level wage rates.Agribusiness,

PLANT ENTRY AND EXIT FROM THE MEATPACKING INDUSTRY DURING PATHOGEN REDUCTION AND HACCP IMPLEMENTATION

Implementation of the Pathogen Reduction and Hazard Analysis and Critical Control Points (PR/HACCP) regulations has now occurred across all U.S. meat and poultry plants. Using databases of plants under federal inspection, we estimate a probit model to determine which factors have affected the probability of exit of meat slaughtering plants during implementation of the regulations.Industrial Organization, Livestock Production/Industries,

Food Safety Audits, Plant Characteristics, and Food Safety Technology Use in Meat and Poultry Plants

Food safety technology can increase a company’s capacity to prevent a foodborne contamination. A food safety audit—a quality control tool in which an auditor observes whether a plant’s processing practices and technologies are compatible with good food safety practices—can indicate how effectively food safety technology is being used. Fast food restaurants, grocery stores, and other major customers of meat and poultry processing plants conduct their own audits or hire auditors to assess the soundness of a plant’s processing operation. Meat and poultry plants can also audit themselves as a way to help maintain process control. In this report, we document the extent of food safety audits in meat and poultry processing plants. We also examine the associations between the use of audits and plant size, firm structure, and food safety technology use. Results show that larger plants, plants subject to food safety audits, and plants that are part of a multiplant firm use more food safety technology than other plants. Plants subject to both plant-hired and customer-hired audits had greater technology use than single (plant- or customer-hired) audit plants.Meat and poultry processing, safety standards, product recalls, food safety technology, food safety audits, Agribusiness, Food Consumption/Nutrition/Food Safety, Industrial Organization, Livestock Production/Industries,

Collision Detection and Administration Methods for Many Particles with Different Sizes

This paper deals with the calculation of the motion and the adminis-tration of the contacts for systems with many colliding bodies of round shape and possibly large size-differences. Both two dimensional (2D) and three dimensional (3D) cases are investigated, while the efficiency of the employed algorithms is compared. For the integration of the equations of motion, standard methods are used, but to reduce the effort for collision detection, more sophisticated administration algorithms for the neighbor-hood search are prosented. Especially for large systems with many parti-cles and a wide, polydisperse size distribution, this is a challenge. Three methods, the Verlet-Neighbor List (VL), the Linked Cell (LC) method, and the Linked Linear List (LLL), are discussed and compared for 2D and 3D. Only LLL performs well for strongly different particle sizes

A Robust and Universal Metaproteomics Workflow for Research Studies and Routine Diagnostics Within 24 h Using Phenol Extraction, FASP Digest, and the MetaProteomeAnalyzer

The investigation of microbial proteins by mass spectrometry (metaproteomics) is a key technology for simultaneously assessing the taxonomic composition and the functionality of microbial communities in medical, environmental, and biotechnological applications. We present an improved metaproteomics workflow using an updated sample preparation and a new version of the MetaProteomeAnalyzer software for data analysis. High resolution by multidimensional separation (GeLC, MudPIT) was sacrificed to aim at fast analysis of a broad range of different samples in less than 24 h. The improved workflow generated at least two times as many protein identifications than our previous workflow, and a drastic increase of taxonomic and functional annotations. Improvements of all aspects of the workflow, particularly the speed, are first steps toward potential routine clinical diagnostics (i.e., fecal samples) and analysis of technical and environmental samples. The MetaProteomeAnalyzer is provided to the scientific community as a central remote server solution at www.mpa.ovgu.de.Peer Reviewe

Mild Cognitive Impairment in the Elderly is Associated with Volume Loss of the Cholinergic Basal Forebrain Region

Background Cholinergic neurons within the basal forebrain are assumed to be an early (preclinical) manifestation site of pathological changes in Alzheimer's disease (AD). Methods We used morphometric magnetic resonance imaging (MRI) to detect and quantify atrophic changes in the basal forebrain of subjects suffering from amnestic mild cognitive impairment (aMCI). Three Tesla magnetic resonance (MR) data of 26 aMCI patients, 46 cognitively normal elderly control subjects (CO), and 12 patients suffering from Alzheimer's dementia were analyzed, including segmentation and quantification of brain tissue as well as a segmentation of basal forebrain structures (substantia innominata [SI]). Results We found the volume of the SI to be significantly different between groups in that control subjects showed the largest SI volumes, followed by aMCI and AD patients. Conclusions These results are in line with the hypothesis that cell loss within the cholinergic basal forebrain regions occurs already in the early (predementia) stage of AD. In vivo quantification of these changes might be of use as a novel neuroimaging marker of cholinergic neurodegeneration in AD