Nano-Engineering Defect Structures on Graphene

We present a new way of nano-engineering graphene using defect domains. These regions have ring structures that depart from the usual honeycomb lattice, though each carbon atom still has three nearest neighbors. A set of stable domain structures is identified using density functional theory (DFT), including blisters, ridges, ribbons, and metacrystals. All such structures are made solely out of carbon; the smallest encompasses just 16 atoms. Blisters, ridges and metacrystals rise up out of the sheet, while ribbons remain flat. In the vicinity of vacancies, the reaction barriers to formation are sufficiently low that such defects could be synthesized through the thermally activated restructuring of coalesced adatoms.Comment: 4 pages, 5 figure

Determining the Impact of Food Price and Income Changes on Obesity

Despite the significant rise in obesity in the U.S., economic research on obesity is still in its infancy. This paper employs a microeconomic approach to investigate the effects of price and income changes on weight in an effort to determine how a high-calorie food tax, a low-calorie food subsidy, and/or an income changes affect body weight. Although raising the price of high-calorie food typically will likely lead to decreased demand for such goods; it is not clear that such an outcome will actually reduce weight. The model developed in this paper identifies conditions under which price and income changes are mostly likely to actually result in a weight loss. The model is easily implemented using data on own-and cross-price elasticities that are often readily available from extant literature. This is important because survey data that contain both economic information, such as food prices, and weight are extremely rare. Information on relationship between price and weight is critical in developing appropriate public policy and in determining when and where fat taxes, thin subsidies or income re-distribution will achieve the desired objective of reducing obesity.Health Economics and Policy,

DESIGNING EXPERIMENTAL AUCTIONS FOR MARKETING RESEARCH: EFFECT OF VALUES, DISTRIBUTIONS, AND MECHANISMS ON INCENTIVES FOR TRUTHFUL BIDDING

Accurately estimating consumer demand for new products is an arduous task made even more difficult by the fact that individuals tend to overstate the amount they are willing to pay for new goods when asked hypothetical questions. Despite their appeal in eliminating hypothetical bias, marketers have been slow to adopt experimental auctions as a standard tool in pre-test market research. One issue that has slowed adoption of the methodology is the proliferation of auction mechanisms and the lack of clear guidance in choosing between mechanisms. In this paper, we provide insight into the theoretical properties of two incentive compatible value elicitation mechanisms, the BDM and Vickrey 2nd price auction, such that practitioners can make more informed decisions in designing experimental auctions to determine consumer willingness-to-pay. In particular, we draw attention to the shapes of the payoff functions and show in a simulation that the two mechanisms differ with respect to the expected cost of deviating from truthful bidding. We show that incentives for truthful bidding depend on the distribution of competing bidders' values and/or prices and individuals' true values for a good. The simulation indicates the 2nd price auction punishes deviations from truthful bidding more severely for high value individuals than the BDM mechanism. These results are confirmed by an experimental study, where we find more accurate bidding for high-value individuals in the 2nd price auction as compared to the BDM. Our results also indicate that when implementing the BDM mechanism, the greatest incentives for truthful value revelation are created when the random price generator is based on a normal distribution centered on an individual's expected true value.Institutional and Behavioral Economics,

A Multidimensional Homo Economicus: Cultural Dimensions of Economic Preferences in Four Countries

Previous work in experimental economics reveals specific differences in economic behavior, especially reciprocity and free-riding behavior, across cultures. We expand the possible pallet of cross-cultural behavioral differences that may exist. We hypothesize that different kinds of strategic interaction and individual decision-making behaviors differ across locations. The variety of experiments we use allow us to report multidimensional rather than just single dimensional differences in behavior across locations. In order to build a broad Homo Economicus we conducted economic experiments in four dissimilar locations: Hangzhou, China; Niamey, Niger; Grenoble, France; Manhattan, Kansas; and West Lafayette, Indiana. Each subject completed an ultimatum bargaining game experiment, Voluntary Contribution Mechanism experiment, time preference experiment, and risk preference experiment. Results indicate economic behavior is not independent of location. Location differences are greatest for strategic interaction behavior and less prevalent for individual decision-making behavior.Time preference, risk preference, voluntary contribution mechanism, Ultimatum bargaining game, cultural, China, France, Niger, Kansas, Indiana, US, Institutional and Behavioral Economics,

The Relative Importance of Preferences for Country-of-Origin in China, France, Niger and the United States

Country-of-origin (COO) is an increasingly politicized credence attribute in the globalizing food system. While international policy development in this area is geographically far-reaching, the benefits of country-of-origin labels (COOL) to producers and consumers from countries in different locations and levels of economic development are not clear. Previous work investigates the importance of COO to consumers, but is typically limited in scope to consumers in one nation. In addition, little is known about the importance of COO information relative to other credence attributes, especially in non-meat food products. This study measures the benefits of COOL to an internationally diverse set of consumers (in developed and developing countries) and estimates their priority rank in policy development. The paper draws upon research in the management literature suggesting consumer information needs are not based on quality alone, but also relate to affective (emotional) and normative (social acceptance) needs. A conjoint experiment is conducted in China, France, Niger and the United States to elicit consumer preferences for COO information, organic production, and genetic modification. The results indicate COO information is not as important as genetically modified content information (France, the United States, and Niger) or organic production information (China). Findings reveal individuals with quality and food safety information needs place higher importance on genetically modified and organic food information than COO information.country-of-origin, genetic modification, organic, conjoint, onion, information, food policy, International Relations/Trade, Q13, Q18, Q17,

Extent and Characteristics of Retail Fresh Beef Branding

Limited information exists regarding the extent and characteristics of branded fresh beef. Retail package data from a sample of grocery stores in three metropolitan areas enabled determining the extent of branded beef for ground beef, roasts, and steaks. Logit models identified factors affecting the probability of beef products being branded, and the probability of beef products carrying specific types of brands compared with store brands and generic (unbranded) beef. The extent of branded beef and type of brand both varied by store type, specific product, quality designation, package type, and presence of special labeling.Marketing,

A Multilevel Approach to Topology-Aware Collective Operations in Computational Grids

The efficient implementation of collective communiction operations has received much attention. Initial efforts produced "optimal" trees based on network communication models that assumed equal point-to-point latencies between any two processes. This assumption is violated in most practical settings, however, particularly in heterogeneous systems such as clusters of SMPs and wide-area "computational Grids," with the result that collective operations perform suboptimally. In response, more recent work has focused on creating topology-aware trees for collective operations that minimize communication across slower channels (e.g., a wide-area network). While these efforts have significant communication benefits, they all limit their view of the network to only two layers. We present a strategy based upon a multilayer view of the network. By creating multilevel topology-aware trees we take advantage of communication cost differences at every level in the network. We used this strategy to implement topology-aware versions of several MPI collective operations in MPICH-G2, the Globus Toolkit[tm]-enabled version of the popular MPICH implementation of the MPI standard. Using information about topology provided by MPICH-G2, we construct these multilevel topology-aware trees automatically during execution. We present results demonstrating the advantages of our multilevel approach by comparing it to the default (topology-unaware) implementation provided by MPICH and a topology-aware two-layer implementation.Comment: 16 pages, 8 figure

Teachers of Students with Emotional and Behavioral Disorders’ Perceptions of the Importance of Selected Professional Standards of Practice

Utilizing the Council for Exceptional Children’s (CEC) standards delineated for preparation programs in teaching students with emotional and behavioral disorders (EBD), the present study sought to determine how graduates of one teacher preparation program perceived the importance of the standards in their work with students with EBD. Results indicated that graduates viewed the CEC standards as important to their work. Further, a multiple regression model examined specific demographic variables (i.e., total years of teaching experience, positions graduates currently held, graduates’ feelings about working with students with EBD, and their feelings as to causal factors leading to EBD) as predictors for how graduates perceive the importance of using the CEC standards. Unfortunately, the regression model did not predict the graduates’ perceived importance in using the CEC standards; however, graduates’ years of teaching experience with students with EBD was a significant predictor for three of the standards

Taking Another Look: Light n-Capture Element Abundances in Metal-Poor Halo Stars

Elements are produced in stars through a variety of processes; some are well known, others are still the object of active research. The elements Zirconium (Zr) and Yttrium (Y) are produced via neutron capture (ncapture). These elements reside in the mass range where there is uncertainty about the production mechanism at early time. The rapid n-capture process (r-process) was believed to be responsible for the production, but no study (Burris et al 2000, Gilroy et al 1988 and others) has been able to successfully use the r-process to reproduce the abundance signature for elements in this mass range for metal-poor halo stars. It has been suggested (Sneden and Cowan 2003) that there may be an undiscovered component to the rprocess. New abundance calculations for these elements have been conducted for a sample of metalpoor halo stars. Transition probabilities for Zr II from (Malcheva et al.2006) and for YII from (Hannaford et al.1982) were utilized in these calculations as well as new high quality observational data from the Keck telescope. The new laboratory and observational data resulted in improvement in the abundance determinations and uncertainty of the abundances