Incorporating Flexible Demand Systems in Empirical Models of Market Power

Measuring the degree of price coordination between firms in a differentiated products industry is particularly challenging because it is necessary to utilize a demand system that is sufficiently flexible, allows the imposition of theoretical restrictions, and allow for the derivation of the functional form of the corresponding price reaction functions. Previous research has relied on restrictive demand systems in order to maintain the tractability of the price reaction functions. The purpose of this paper is determine whether using more flexible demand systems can yield a set of first-order profit maximization conditions that are mathematically tractable and amendable to estimation. The demand systems considered are the Almost Ideal Demand System (AIDS), the Linear Approximate Almost Ideal Demand System (LAIDS), and the Rotterdam demand system. This paper also expands prior work on estimating brand level demand elasticities by endogenizing category level expenditures in the context of a weakly separable demand system. This yields some new and interesting insights for the measurement of market power in differentiated product industries. We show that while it is not possible to derive explicit price reaction functions for any of these demand systems, given certain assumptions, the Rotterdam demand system does yield an explicit set of profit maximization first-order conditions that can be estimated.Demand and Price Analysis,

Solid-State Microwave Electronics

Contains reports on status of research and nine research projects.National Aeronautics and Space Administration (Grant NGR-22-009-163

An analysis of the carbon balance of the Arctic Basin from 1997 to 2006

Author Posting. © The Authors, 2010. This is the author's version of the work. It is posted here by permission of John Wiley & Sons for personal use, not for redistribution. The definitive version was published in Tellus B 62 (2010): 455-474, doi:10.1111/j.1600-0889.2010.00497.x.This study used several model-based tools to analyze the dynamics of the Arctic Basin between 1997 and 2006 as a linked system of land-ocean-atmosphere C exchange. The analysis estimates that terrestrial areas of the Arctic Basin lost 62.9 Tg C yr-1 and that the Arctic Ocean gained 94.1 Tg C yr-1. Arctic lands and oceans were a net CO2 sink of 108.9 Tg C yr-1, which is within the range of uncertainty in estimates from atmospheric inversions. Although both lands and oceans of the Arctic were estimated to be CO2 sinks, the land sink diminished in strength because of increased fire disturbance compared to previous decades, while the ocean sink increased in strength because of increased biological pump activity associated with reduced sea ice cover. Terrestrial areas of the Arctic were a net source of 41.5 Tg CH4 yr-1 that increased by 0.6 Tg CH4 yr-1 during the decade of analysis, a magnitude that is comparable with an atmospheric inversion of CH4. Because the radiative forcing of the estimated CH4 emissions is much greater than the CO2 sink, the analysis suggests that the Arctic Basin is a substantial net source of green house gas forcing to the climate system.This study was supported, in part, by the NSF Arctic System Science Program as part of the Arctic Carbon Cycle Synthesis Project (ARC-0531047, 0531082, 0531119, and 0554811)

Instances and connectors : issues for a second generation process language

This work is supported by UK EPSRC grants GR/L34433 and GR/L32699Over the past decade a variety of process languages have been defined, used and evaluated. It is now possible to consider second generation languages based on this experience. Rather than develop a second generation wish list this position paper explores two issues: instances and connectors. Instances relate to the relationship between a process model as a description and the, possibly multiple, enacting instances which are created from it. Connectors refers to the issue of concurrency control and achieving a higher level of abstraction in how parts of a model interact. We believe that these issues are key to developing systems which can effectively support business processes, and that they have not received sufficient attention within the process modelling community. Through exploring these issues we also illustrate our approach to designing a second generation process language.Postprin

Pumping liquid manure from swine lagoons and holding ponds

1 online resource (PDF, 6 pages)This archival publication may not reflect current scientific knowledge or recommendations. Current information available from the University of Minnesota Extension: https://www.extension.umn.edu

Linkages among runoff, dissolved organic carbon, and the stable oxygen isotope composition of seawater and other water mass indicators in the Arctic Ocean

Author Posting. © American Geophysical Union, 2005. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 110 (2005): G02013, doi:10.1029/2005JG000031.Concentrations of dissolved organic carbon (DOC) and δ18O values have been determined following sampling of runoff from a number of major arctic rivers, including the Ob, Yenisey, Lena, Kolyma, Mackenzie and Yukon in 2003-2004. These data are considered in conjunction with marine data for DOC, δ18O values, nutrients, salinity, and fluorometric indicators of DOC that were obtained as part of the Shelf-Basin Interactions program at the continental shelf-basin boundary of the Chukchi and Beaufort Seas. These marine data indicate that the freshwater component is most likely derived from regional sources, such as the Mackenzie, the Bering Strait inflow and possibly eastern Siberian rivers, including the Kolyma, or the Lena but not rivers further west in the Eurasian arctic. Contributions of freshwater from melted sea ice to marine surface waters appeared to be insignificant over annual cycles compared to runoff, although on a seasonal basis, freshwater from melted sea ice was locally dominant following a major sea-ice retreat into the Canada Basin in 2002. DOC concentrations were correlated with the runoff fraction, with an apparent meteoric water DOC concentration of 174 ± 1 μM (standard error). This concentration is lower than the flow-weighted concentrations measured at river mouths of the five largest Arctic rivers (358 to 917 μM), indicating that removal of terrigenous DOC during transport through estuaries, shelves and in the deep basin. DOC data indicate that flow-weighted concentrations in the two largest North American arctic rivers, the Yukon (625μM) and the Mackenzie (382 μM), are lower than in the three largest Eurasian arctic rivers, the Ob (825 μM), the Yenesey (858 μM) and the Lena (917 μM). A fluorometric indicator of chromophoric dissolved organic matter (CDOM) that has provided estimates of terrigenous DOC concentrations in the Eurasian Arctic was not correlated with DOC concentrations in the Amerasian marine waters studied, except below the upper Arctic Ocean halocline. Nutrient distributions and concentrations as well as derived nutrient ratios suggest the CDOM fluorometer may be responding to the release of chromophoric materials from continental shelf sediments. Shipboard incubation experiments with undisturbed sediment cores indicate that continental shelf sediments on the Bering and Chukchi Sea shelves are likely to be a net source of DOC to the Arctic Ocean.The PARTNERS and SBI projects have been supported by the Office of Polar Programs of the U.S. National Science Foundation

Tumour suppressor ING1b maintains genomic stability upon replication stress

The lesion bypass pathway, which is regulated by monoubiquitination of proliferating cell nuclear antigen (PCNA), is essential for resolving replication stalling due to DNA lesions. This process is important for preventing genomic instability and cancer development. Previously, it was shown that cells deficient in tumour suppressor p33ING1 (ING1b) are hypersensitive to DNA damaging agents via unknown mechanism. In this study, we demonstrated a novel tumour suppressive function of ING1b in preserving genomic stability upon replication stress through regulating PCNA monoubiquitination. We found that ING1b knockdown cells are more sensitive to UV due to defects in recovering from UV-induced replication blockage, leading to enhanced genomic instability. We revealed that ING1b is required for the E3 ligase Rad18-mediated PCNA monoubiquitination in lesion bypass. Interestingly, ING1b-mediated PCNA monoubiquitination is associated with the regulation of histone H4 acetylation. Results indicate that chromatin remodelling contributes to the stabilization of stalled replication fork and to the regulation of PCNA monoubiquitination during lesion bypass

Communications Biophysics

Contains research objectives and summary of research on nine research projects split into four sections.National Institutes of Health (Grant 5 ROI NS11000-03)National Institutes of Health (Grant 1 P01 NS13126-01)National Institutes of Health (Grant 1 RO1 NS11153-01)National Institutes of Health (Grant 2 R01 NS10916-02)Harvard-M.I.T. Rehabilitation Engineering CenterU. S. Department of Health, Education, and Welfare (Grant 23-P-55854)National Institutes of Health (Grant 1 ROl NS11680-01)National Institutes of Health (Grant 5 ROI NS11080-03)M.I.T. Health Sciences Fund (Grant 76-07)National Institutes of Health (Grant 5 T32 GM07301-02)National Institutes of Health (Grant 5 TO1 GM01555-10

Preferences for the Sex of Offspring and Demographic Behavior in Eighteenth- and Nineteenth-Century Germany: an Examination of Evidence From Village Genealogies

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68167/2/10.1177_036319908000500202.pd