Packed red blood cells (RBC) are main blood components used in transfusiology. During storage, preserved blood cells undergo progressive structural and functional changes that may reduce red-cell ...function and viability after transfusion. As the hemoglobin is the main and active component of erythrocytes, we consider that oxidized hemoglobin derivatives formation cause those changes. With the aim of developing the new criteria for donated blood suitability for transfusion, we studied storage-related changes in red blood cells hemoglobin by means of analytical fitting of Mössbauer spectra. We analyzed Mössbauer spectra of set RBC’s samples from volunteer donors every few days during their storage. Using those data, we built kinetic curves of various hemoglobin derivatives changes during RBC storage for different hemoglobin forms concentration in RBC samples. We found that kinetic curves are specific for each donor. They also depend on the donor’s age and health condition at the time of donation. Based on our spectroscopy results we suggested an objective criteria for duration of storage of regular donors RBC.
Measuring competition in spatial retail Ellickson, Paul B.; Grieco, Paul L.E.; Khvastunov, Oleksii
The Rand journal of economics,
04/2020, Letnik:
51, Številka:
1
Journal Article
Recenzirano
We propose and estimate a spatially aggregated discrete-choice model with overlapping consumer choice sets and demographic-driven heterogeneity that varies by chain. Our approach avoids the need to ...define markets ex ante and captures rich substitution patterns, even in the absence of price data. An application to the US grocery industry illustrates the importance of location, format, and the spatial distribution of consumers in shaping the competitive environment. Contrary to conventional wisdom, we find substantial cross-format competition between supercenters, clubs, and traditional grocers. Finally, we evaluate two representative mergers between supermarket chains to demonstrate how our estimates inform antitrust policy.
The art market of the Siberian regions is in its nascent stage and in search of its own identity, its own unique regional features capable of making art goods more competitive. Art salons and ...galleries as main art business centers play a very important role in adjusting the mechanisms of intra-institutional positive dynamics as they specify the way of development of the region's fine art, cooperate with leading artists, serve as a communication means between the artist and the consumer, and set prices in the art sphere. The purpose of this paper is to analyze the dynamics of development of Krasnoyarsk's art market in the context of development of the All-Russian fine art market, to identify its strengths and weaknesses, and to determine key factors that positively or negatively affect this market's competitiveness. The paper presents the whole situation in the country's art market and analyzes statistical data about Krasnoyarsk's art market. It shows existing conditions and characteristics that identify the regional art market's specific features and reveals main problems associated with this market's development. Methods used to study are analysis of economic statistics, study of marketing strategies of leading art galleries and salons, interviews with sellers, managers and potential buyers. The conclusions of this study can help to create a rational strategy for positive development of the Siberian cities' art market and can be used for identifying the prospects of development of the regional fine art market in the future.
Overview This dissertation investigates spatial competition between grocery retailers in the U.S. and grocery consumption patterns of households. It is organized as follows: In chapter one, I ...analyzed spatial competition between grocery retailers and importance of club stores for the grocery industry. In chapter two, I implemented structural demand model to understand determinants of household consumption in terms of healthiness. In chapter three, I used reduced form approach to investigate importance of access to grocery stores for quantity and quality of household’s consumption. Measuring Competition in Spatial Retail (with Paul Ellickson and Paul Grieco) We propose a framework for analyzing spatial competition between retailers of different formats. Our approach yields localized measures of concentration and store-level diversion ratios that can be used to prospectively evaluate mergers in highly differentiated retail markets. Our method does not require the analyst to define markets ex ante, collect prices or construct ad hoc price indices. Using data from the supermarket industry, we evaluate two representative mergers. Contrary to conventional wisdom, we find substantial cross-format competition between supercenters, club stores, and traditional grocers. Our analysis cautions against ignoring the impact of new formats when evaluating mergers between traditional grocers. Healthiness of Consumption and Retail Environment The determinants of a households’ diet decision have been studied extensively. This paper contributes to the literature by focusing on how store type, store size, household income, and distance to store affects healthiness of household consumption. I am implementing a micro-founded structural model which includes grocery budget allocation across stores and food types in the vicinity of household location. The micro-founded model allows me to capture the rich heterogeneity in the retail environment that a household is facing. The estimated model permitted me to conduct a counterfactual experiment. The experiment showed that product variety and traveling costs are more important for households than additional income. This result is even more drastic for low income households living far from large stores. Grocery Store Proximity and Diet Composition The relationship between the distance to a supermarket and household diet has been studied by establishing the correlation between both variables. The studies were not able to make a causal statement about the effect of additional miles to a large grocery store and supermarket upon the quantity and quality of consumption. In this paper I suggest the instrument (average income in the area) for stores’ location which would allow me to determine how additional miles to the supermarket or large grocery store affects quantity and quality of consumption in terms of healthiness. Obtained results suggest that additional mile traveled to the stores decreases grocery expenditures by 19.5 % in the low dense areas and by 23.5 % in the high dense areas. Another obtained result is that additional mile to the store reduces share of healthy consumption by 11.7 % in areas with low density and by 13.6 % in high dense areas.
In a superlattice placed in crossed static electric and magnetic fields, under certain conditions, the inversion of electron population can appear at which the average energy of electrons is above ...the middle of the mini-band and the effective mass of the electron is negative. This is the implementation of the negative effective mass amplifier and generator (NEMAG) in the superlattice. It can result in the amplification and generation of terahertz radiation even in the absence of negative differential conductivity.
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