1,288 research outputs found
Follow the Leader: Adoption Behavior in Food Retailers' Decision to Offer Fresh Irradiated Ground Beef
During the 14-month period from May 2002 to June 2003, approximately 10 percent of U.S. supermarkets began to offer fresh irradiated ground beef under the stores' own labels. Using a survey of supermarket store managers from this time period, this paper investigates the factors that influenced new product offerings and adoptions. Results from the adoption model show that factors associated with competition and structure in the food retailing industry play a strong role in the decision. Among other results, we find that variables relating to a competitor's adoption status and proximity significantly affect a store's decision to offer fresh irradiated ground beef.Marketing,
Adoption Behavior in Food Retailers' Decision to Offer Fresh Irradiated Ground Beef
During the 14-month period from May 2002 to June 2003, approximately 10 percent of U.S. supermarkets began to offer fresh irradiated ground beef under the stores' own labels. Using a survey of supermarket store managers from this time period, this paper investigates the factors that influenced stores' adoption of irradiated ground beef. Results from the adoption model show that factors associated with competition, merchandising philosophy, and structure in the food retailing industry play a strong role in the decision. Among other results, we find that variables relating to a competitor's adoption status and proximity can increase the likelihood of a store's adoption decision.Marketing,
Yos9p assists in the degradation of certain non-glycosylated proteins from the endoplasmic reticulum
The HRD ubiquitin ligase recognizes and ubiquitylates proteins of the endoplasmic reticulum that display structural defects. Here, we apply quantitative proteomics to characterize the substrate spectrum of the HRD complex. Among the identified substrates is Erg3p, a glycoprotein involved in sterol-synthesis. We characterize Erg3p and demonstrate that the elimination of Erg3p requires Htm1p and Yos9p, two proteins that partake in the glycan-dependent turnover of aberrant proteins. We further show that the HRD ligase also mediates the breakdown of Erg3p and CPY* engineered to lack N-glycans. The degradation of these non-glycosylated substrates is enhanced by a mutant variant of Yos9p that has lost its affinity for oligosaccharides, indicating that Yos9p has a previously unrecognized role in the quality control of non-glycosylated proteins
Visual exploration of climate variability changes using wavelet analysis
Due to its nonlinear nature, the climate system shows quite high natural variability on different time scales, including multiyear oscillations such as the El Ni˜no Southern Oscillation phenomenon. Beside a shift of the mean states and of extreme values of climate variables, climate change may also change the frequency or the spatial patterns of these natural climate variations. Wavelet analysis is a well established tool to investigate variability in the frequency domain. However, due to the size and complexity of the analysis results, only few time series are commonly analyzed concurrently. In this paper we will explore different techniques to visually assist the user in the analysis of variability and variability changes to allow for a holistic analysis of a global climate model data set consisting of several variables and extending over 250 years. Our new framework and data from the IPCC AR4 simulations with the coupled climate model ECHAM5/MPI-OM are used to explore the temporal evolution of El Ni˜no due to climate change
Some comments on -annihilation branching ratios into -, - and -channels
We give some remarks on the -partial branching ratios in flight at
low momenta of antineutron, measured by OBELIX collaboration. The comparison is
made to the known branching ratios from the -atomic states. The
branching ratio for the reaction is found to be
suppressed in comparison to what follows from the -data. It is also
shown, that there is no so called dynamic I=0-amplitude suppression for the
process .Comment: 8 pages, LaTeX, no figure
Large Oligomeric Complex Structures Can Be Computationally Assembled by Efficiently Combining Docked Interfaces
Macromolecular oligomeric assemblies are involved in many biochemical processes of living organisms. The benefits of such assemblies in crowded cellular environments include increased reaction rates, efficient feedback regulation, cooperativity and protective functions. However, an atom‐level structural determination of large assemblies is challenging due to the size of the complex and the difference in binding affinities of the involved proteins. In this study, we propose a novel combinatorial greedy algorithm for assembling large oligomeric complexes from information on the approximate position of interaction interfaces of pairs of monomers in the complex. Prior information on complex symmetry is not required but rather the symmetry is inferred during assembly. We implement an efficient geometric score, the transformation match score, that bypasses the model ranking problems of state‐of‐the‐art scoring functions by scoring the similarity between the inferred dimers of the same monomer simultaneously with different binding partners in a (sub)complex with a set of pregenerated docking poses. We compiled a diverse benchmark set of 308 homo and heteromeric complexes containing 6 to 60 monomers. To explore the applicability of the method, we considered 48 sets of parameters and selected those three sets of parameters, for which the algorithm can correctly reconstruct the maximum number, namely 252 complexes (81.8%) in, at least one of the respective three runs. The crossvalidation coverage, that is, the mean fraction of correctly reconstructed benchmark complexes during crossvalidation, was 78.1%, which demonstrates the ability of the presented method to correctly reconstruct topology of a large variety of biological complexes. Proteins 2015; 83:1887–1899. © 2015 The Authors. Proteins: Structure, Function, and Bioinformatics Published by Wiley Periodicals, Inc
Microbiology and atmospheric processes: research challenges concerning the impact of airborne micro-organisms on the atmosphere and climate
For the past 200 years, the field of aerobiology has explored the abundance, diversity, survival and transport of micro-organisms in the atmosphere. Micro-organisms have been explored as passive and severely stressed riders of atmospheric transport systems. Recently, an interest in the active roles of these micro-organisms has emerged along with proposals that the atmosphere is a global biome for microbial metabolic activity and perhaps even multiplication. As part of a series of papers on the sources, distribution and roles in atmospheric processes of biological particles in the atmosphere, here we describe the pertinence of questions relating to the potential roles that air-borne micro-organisms might play in meteorological phenomena. For the upcoming era of research on the role of air-borne micro-organisms in meteorological phenomena, one important challenge is to go beyond descriptions of abundance of micro-organisms in the atmosphere toward an understanding of their dynamics in terms of both biological and physico-chemical properties and of the relevant transport processes at different scales. Another challenge is to develop this understanding under contexts pertinent to their potential role in processes related to atmospheric chemistry, the formation of clouds, precipitation and radiative forcing. This will require truly interdisciplinary approaches involving collaborators from the biological and physical sciences, from disciplines as disparate as agronomy, microbial genetics and atmosphere physics, for example
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