SUPERMARKET CHARACTERISTICS AND OPERATING COSTS IN LOW-INCOME AREAS

Whether the poor pay more for food than other income groups is an important question in food price policy research. Stores serving low-income shoppers differ in important ways from stores that receive less of their revenues from Food Stamp redemptions. Stores with more revenues from Food Stamps are generally smaller and older, and offer relatively fewer convenience services for shoppers. They also offer a different mix of products, with a relatively high portion of sales coming from meat and private-label products. Metro stores with high Food Stamp redemption rates lag behind other stores in the adoption of progressive supply chain and human resource practices. Finally, stores with the highest Food Stamp redemption rates have lower sales margins relative to other stores, but have significantly lower payroll costs as a percentage of sales. Overall, operating costs for stores with high Food Stamp redemption rates are not significantly different from those for stores with moderate Food Stamp redemption rates. If the poor do pay more, factors other than operating costs are likely to be the reason.Food prices, supermarkets, low-income consumers, Food Stamps, metro, nonmetro, Marketing,

Alpha MAML: Adaptive Model-Agnostic Meta-Learning

Model-agnostic meta-learning (MAML) is a meta-learning technique to train a model on a multitude of learning tasks in a way that primes the model for few-shot learning of new tasks. The MAML algorithm performs well on few-shot learning problems in classification, regression, and fine-tuning of policy gradients in reinforcement learning, but comes with the need for costly hyperparameter tuning for training stability. We address this shortcoming by introducing an extension to MAML, called Alpha MAML, to incorporate an online hyperparameter adaptation scheme that eliminates the need to tune meta-learning and learning rates. Our results with the Omniglot database demonstrate a substantial reduction in the need to tune MAML training hyperparameters and improvement to training stability with less sensitivity to hyperparameter choice.Comment: 6th ICML Workshop on Automated Machine Learning (2019

The Planar Singular Solutions of Stokes and Laplace Equations and their Application to Transport Processes Near Porous Surfaces

The planar singular solutions of Stokes and Laplace equations are derived and applied to a number of transport problems associated with porous surfaces. The velocity, pressure, concentration, and temperature slip coefficients are determined exactly for the semi-infinite periodic arrays of spheres and these are compared with the predictions of two approximate continuum theories formulated by Brinkman [Appl. Sci. Res. Sect. A I, 27 (1947)] and Chang and Acrivos [J. Appl. Phys. 59, 375 (1986)] to assess the utility of such theories in accurately predicting various overall properties related to the porous surfaces. It is found that in general these theories provide fairly accurate estimates of these properties even when the length scales based on the relevant macroscopic properties such as the permeability are much smaller than the length scales characterizing the microstructure of the porous media

Sixth-Order Two-Point Efficient Family of Super-Halley Type Methods

The main focus of this manuscript is to provide a highly efficient two-point sixth-order family of super-Halley type methods that do not require any second-order derivative evaluation for obtaining simple roots of nonlinear equations, numerically. Each member of the proposed family requires two evaluations of the given function and two evaluations of the first-order derivative per iteration. By using Mathematica-9 with its high precision compatibility, a variety of concrete numerical experiments and relevant results are extensively treated to confirm t he t heoretical d evelopment. From their basins of attraction, it has been observed that the proposed methods have better stability and robustness as compared to the other sixth-order methods available in the literature

THE 2003 SUPERMARKET PANEL ANNUAL REPORT

Executive Summary The Food Industry Center established the Supermarket Panel in 1998 as the basis for an ongoing study of the supermarket industry. Since 2000 the core of the Panel has been a random sample of stores drawn from the approximately 32,000 supermarkets in the U.S. that accept food stamps. The purpose of collecting data on supermarket operations and performance is to: Provide timely, useful information for the industry through benchmark reports and annual summaries, trends on key indices of technology adoption, competitive positions and performance. Be a ready source of data for research on current and emerging issues - to be able to track the changes in operation and its impacts on performance over time. This report presents findings from the 2003 Supermarket Panel, and provides an overview of findings from the past four years. The 2003 Panel includes 391 stores that are a representative cross-section of the supermarket industry. The Panel tries to follow the same stores over time. Of the 391 stores, 268 were in the Panel in 2002. Nine percent of the stores have been in the Panel all four years. At least one store from every state is in the Panel. New in 2003 The Panel was offered over the Internet. Forty-seven percent responded on-line. An index on variety offering was created. Questions about offering irradiated fresh ground beef are included (with a follow up study). Supply Chain Technology Practices The Supply Chain Score measures the extent to which stores have adopted computerized methods of communicating with suppliers, handling inventory management, ordering, invoicing, and analyzing consumer purchases. The average score has almost doubled in four years. Stores in groups (chains) with more than 750 stores and/or supercenter formats have adopted supply chain practices most intensively. Internet/Intranet is used by at least two-thirds of all stores; over ninety percent of stores in groups with more than 50 stores use this technology. Vendor managed inventory has been adopted by only 42 percent of stores in the biggest store groups with much lower rates of adoption in smaller store groups. A higher Supply Chain Score benefited significantly higher sales per labor hour. Service and Variety Scores About eighty percent of stores in all size groups offer bagging and custom meat cutting. Variety pays off in better performance for five out of eight measures. Variety helps to grow annual percentage sales. Supercenters/Top Stores/Unions Supercenters have significantly higher sales per labor hour and per transaction. They have lower sales growth. Fifty-three percent of supermarkets face supercenter competition. They have somewhat higher sales per square foot of selling area and higher annual sales growth than stores that do not face supercenter competition. Eleven percent of stores in the 2003 Panel qualified as "top stores." They had above the median levels for each of three performance measures: weekly sales per square foot, sales per labor hour, and annual percentage sales growth. Top stores are more likely to have a unionized labor force, be a price and variety leader, and be wholesaler supplied. One-third of 2003 Panel stores have unionized labor. These stores have more productive labor with significantly higher sales per labor hour. Statistically Significant Drivers of Performance Over Time The descriptive profile and analysis of the Panel provide useful insights on the structure of the supermarket industry and factors associated with strong performance. However, statistical regression analysis identifies whether a variable is significantly correlated with a performance measure holding all else constant. This section presents findings from a multivariate regression analysis of five key performance measures. These regression analyses are summarized on the table below. If a characteristic is listed on the table it was a significant correlate in at least three out of the past four years. For example, in the last row, the only variable that was consistently significant for increasing annual percentage sales growth is being in an area with higher household incomes. Having a warehouse format decreased sales growth and three other factors were significant in at least three years but alternated with positive and negative effects.Industrial Organization, Marketing,

Simple models for the heat flux from the Atlantic meridional overturning cell to the atmosphere

It has been suggested that a slowdown of the Atlantic meridional overturning cell (AMOC) would cause the Northern Hemisphere to cool by a few degrees. We use a sequence of simple analytical models to show that due to the nonlinearity of the system, the simplified heat flux from the modeled AMOC to the atmosphere above is so robust that even changes of as much as 50% in the present AMOC transport are not enough to significantly change the temperature of the outgoing warmed atmosphere (i.e., the fraction of the atmosphere warmed by the AMOC). Our most realistic model (which is still a far cry from reality) involves a warm ocean losing heat to an otherwise motionless and colder atmosphere. As a result, the compressible atmosphere convects, and the generated airflow ultimately penetrates horizontally into the surrounding air. The behavior of the system is attributable to four key aspects of the underlying physical processes: (1) convective atmospheric transport increases by warming the atmosphere, (2) the ocean is warmer than the atmosphere, (3) the surface heat flux is usually proportional to the temperature difference between the ocean and the atmosphere, and (4) the specific heat capacity of water is much larger than that of the air. Taken together, these properties of the system lead to the existence of a dynamic “asymptotic” state, a modeled regime, in which even significant changes in the AMOC transport have almost no effect on the ocean-atmosphere heat flux and the resulting outgoing atmospheric temperature. In the hypothetical limit of an infinitely large specific heat capacity of water, Cpw there is no change in either the atmospheric transport or the temperatures of the ocean and the atmosphere, regardless of how large the reduction in the AMOC transport is. Although our models may be too simple to allow for a direct application to the ocean and atmosphere, they do shed light on the processes in question

Wheat x Azotobacter x VA Mycorrhiza interactions towards plant nutrition and growth – a review

Nitrogen-fixing and phosphate-mobilizing bateria, as well as mycorrhizal fungi, can influence plant nutrition beneficially and thus be used as biofertilizers in agriculture. This paper briefly reviews the role of wheat genotypes in the interaction of wheat with soil microorganisms like phosphate solubilizing and nitrogen fixing bacteria, specifically Azotobacter sp., and with mycorrhizal fungi for the development of sustainable wheat crop production. The role of rhizosphere microorganisms and the mechanisms, factors affecting response of bioinoculants and the possibilities of breeding wheat genotypes responsive to these bioinoculants for sustainable wheat production in semi-arid tropics are discussed.

Screening For Neurotoxic Potential Of 15 Flame Retardants Using Freshwater Planarians

Asexual freshwater planarians are an attractive invertebrate model for high-throughput neurotoxicity screening, because they possess multiple quantifiable behaviors to assess distinct neuronal functions. Planarians uniquely allow direct comparisons between developing and adult animals to distinguish developmentally selective effects from general neurotoxicity. In this study, we used our automated planarian screening platform to compare the neurotoxicity of 15 flame retardants (FRs), consisting of representative phased-out brominated (BFRs) and replacement organophosphorus FRs (OPFRs). OPFRs have emerged as a proposed safer alternative to BFRs; however, limited information is available on their health effects. We found 11 of the 15 FRs (3/6 BFRs, 7/8 OPFRs, and Firemaster 550) caused adverse effects in both adult and developing planarians with similar nominal lowest-effect-levels for BFRs and OPFRs. This suggests that replacement OPFRs are comparably neurotoxic to the phased-out compounds. BFRs were primarily systemically toxic, whereas OPFRs, except Tris(2-chloroethyl) phosphate, shared a behavioral phenotype in response to noxious heat at sublethal concentrations, indicating specific neurotoxic effects. We found this behavioral phenotype was correlated with cholinesterase inhibition, thus linking behavioral outcomes to molecular targets. By directly comparing effects on adult and developing planarians, we further found that one BFR (3,3′,5,5′-Tetrabromobisphenol A) caused a developmental selective defect. Together, these results demonstrate that our planarian screening platform yields high content data from various behavioral and morphological endpoints, allowing us to distinguish selective neurotoxic effects and effects specific to the developing nervous system. Ten of these 11 bioactive FRs were previously found to be bioactive in other models, including cell culture and alternative animal models (nematodes and zebrafish). This level of concordance across different platforms emphasizes the urgent need for further evaluation of OPFRs in mammalian systems

Phylogeography and domestication of Indian river buffalo

<p>Abstract</p> <p>Background</p> <p>The water buffalo- <it>Bu</it><it>balus bubalis </it>holds tremendous potential in livestock sector in many Asian countries, particularly India. The origin, domestication and genetic structure of the Indian river buffalo are poorly understood. Therefore, to understand the relationship among the maternal lineages of Indian river buffalo breeds and their domestication process, we analysed mitochondrial D-loop region of 217 animals representing eight breeds from eight different locations in India along with published sequences of Mediterranean buffalo.</p> <p>Results</p> <p>The maximum parsimony tree showed one major clade with six internal branches. Reduced median network revealed expansion from more than one set of haplotypes indicating complex domestication events for this species. In addition, we found several singleton haplotypes. Using rho statistics, we obtained a time estimate of 6300 years BP for the expansion of one set of hapltoypes of the Indian domestic buffalo. A few breed specific branches in the network indicated an ancient time depth of differentiation of some of the maternal lineages of river buffalo breeds. The multidimensional display of breed pairwise F_STvalues showed significant breed differentiation.</p> <p>Conclusion</p> <p>Present day river buffalo is the result of complex domestication processes involving more than one maternal lineage and a significant maternal gene flow from the wild populations after the initial domestication events. Our data are consistent with the available archaeological information in supporting the proposition that the river buffalo was likely to be domesticated in the Western region of the Indian subcontinent, specifically the present day breeding tracts of the Mehsana, Surati and Pandharpuri breeds.</p