RESERVATION PRICE ANNOUNCEMENT IN SEALED BID AUCTIONS: COMMENT

This comment corrects some errors of analysis contained in a 1993 paper by Carey in the Journal of Industrial Economics.auction, reservation price

Captive Supplies and Cash Market Prices for Fed Cattle: A Dynamic Rational Expectations Model of Delivery Timing

Several empirical analyses of data from fed cattle markets have found a negative correlation between a region's weekly delivery volume of captive supply cattle and contemporaneous price in the local cash market. This negative correlation has been cited as evidence of a causal relationship between the two variables; a relationship in which buyers (beef packing plants) use captive supply procurement as an instrument to depress prices paid to cash market sellers (feeders). This paper investigates circumstances under which this empirical regularity might emerge as a benign artifact of buyer and seller behavior in a fed cattle market in which both sides are price takers. One feature of these markets is that sellers of both marketing agreement (the predominant captive supply procurement method) cattle and spot market cattle have some flexibility in scheduling delivery in order to take advantage of expected price changes. The effect that this type of inter-temporal arbitrage has on the dynamics of price and captive supply is investigated using simulation methods applied to a rational expectations model of delivery timing incentives.cattle markets; captive supplies; extended path algorithm

AGRICULTURAL PRICE SPREADS AND MARKET PERFORMANCE

Demand and Price Analysis, Marketing,

Captive Supplies and Cash Market Prices for Fed Cattle: The Role of Delivery Timing Incentives

The use of non-cash methods of procuring fed cattle for slaughter has led to concern about the effect of these so-called “captive” supplies on cash market prices. Some empirical evidence suggests that there is a negative short-run relationship between the two: Cash market prices tend to be low in weeks in which captive supply shipments are high. We advance a different perspective on the relationship between captive deliveries and cash prices, arguing that the incentives that influence cattle delivery-scheduling decisions could lead to a negative relationship, not between the contemporaneous levels of captive shipments and price, but between the volume of captive deliveries, on the one hand, and an ex ante expectation of a week-to-week price change, on the other. Econometric testing provides some evidence of this empirical regularity in the cattle procurement activities of four large packing plants in Texas in the mid-1990s

A Re-Examination of Multistage Economies in Hog Farming

Current trends in the structure of hog production in the U.S. are toward facilities that are not only larger, but also more likely to be specialized, carrying out only some of the vertically linked phases of production in the same facility. This paper investigates the cost efficiency incentives for these changes by estimating a multistage cost function for hog production. Data are from the Hog Production Practices and Costs portion of the USDA’s 2004 Agricultural Resource Management Survey

Longitudinal Diffusion Tensor Imaging Resembles Patterns of Pathology Progression in Behavioral Variant Frontotemporal Dementia (bvFTD)

Objective: Recently, the characteristic longitudinal distribution pattern of the underlying phosphorylated TDP-43 (pTDP-43) pathology in the behavioral variant of frontotemporal dementia (bvFTD) excluding Pick's disease (PiD) across specific brain regions was described. The aim of the present study was to investigate whether in vivo investigations of bvFTD patients by use of diffusion tensor imaging (DTI) were consistent with these proposed patterns of progression. Methods: Sixty-two bvFTD patients and 47 controls underwent DTI in a multicenter study design. Of these, 49 bvFTD patients and 34 controls had a follow-up scan after ~12 months. Cross-sectional and longitudinal alterations were assessed by a two-fold analysis, i.e., voxelwise comparison of fractional anisotropy (FA) maps and a tract of interest-based (TOI) approach, which identifies tract structures that could be assigned to brain regions associated with disease progression. Results: Whole brain-based spatial statistics showed white matter alterations predominantly in the frontal lobes cross-sectionally and longitudinally. The TOIs of bvFTD neuroimaging stages 1 and 2 (uncinate fascicle—bvFTD pattern I; corticostriatal pathway—bvFTD pattern II) showed highly significant differences between bvFTD patients and controls. The corticospinal tract-associated TOI (bvFTD pattern III) did not differ between groups, whereas the differences in the optic radiation (bvFTD pattern IV) reached significance. The findings in the corticospinal tract were due to a “dichotomous” behavior of FA changes there. Conclusion: Longitudinal TOI analysis demonstrated a pattern of white matter pathways alterations consistent with patterns of pTDP-43 pathology

hnRNP I Inhibits Notch Signaling and Regulates Intestinal Epithelial Homeostasis in the Zebrafish

Regulated intestinal stem cell proliferation and differentiation are required for normal intestinal homeostasis and repair after injury. The Notch signaling pathway plays fundamental roles in the intestinal epithelium. Despite the fact that Notch signaling maintains intestinal stem cells in a proliferative state and promotes absorptive cell differentiation in most species, it remains largely unclear how Notch signaling itself is precisely controlled during intestinal homeostasis. We characterized the intestinal phenotypes of brom bones, a zebrafish mutant carrying a nonsense mutation in hnRNP I. We found that the brom bones mutant displays a number of intestinal defects, including compromised secretory goblet cell differentiation, hyperproliferation, and enhanced apoptosis. These phenotypes are accompanied by a markedly elevated Notch signaling activity in the intestinal epithelium. When overexpressed, hnRNP I destabilizes the Notch intracellular domain (NICD) and inhibits Notch signaling. This activity of hnRNP I is conserved from zebrafish to human. In addition, our biochemistry experiments demonstrate that the effect of hnRNP I on NICD turnover requires the C-terminal portion of the RAM domain of NICD. Our results demonstrate that hnRNP I is an evolutionarily conserved Notch inhibitor and plays an essential role in intestinal homeostasis

Plasma-liquid interactions: a review and roadmap

Plasma-liquid interactions represent a growing interdisciplinary area of research involving plasma science, fluid dynamics, heat and mass transfer, photolysis, multiphase chemistry and aerosol science. This review provides an assessment of the state-of-the-art of this multidisciplinary area and identifies the key research challenges. The developments in diagnostics, modeling and further extensions of cross section and reaction rate databases that are necessary to address these challenges are discussed. The review focusses on non-equilibrium plasmas