Embedding a pair of graphs in a surface, and the width of 4-dimensional prismatoids

A prismatoid is a polytope with all its vertices contained in two parallel facets, called its bases. Its width is the number of steps needed to go from one base to the other in the dual graph. The first author recently showed that the existence of counter-examples to the Hirsch conjecture is equivalent to that of $d$-prismatoids of width larger than $d$, and constructed such prismatoids in dimension five. Here we show that the same is impossible in dimension four. This is proved by looking at the pair of graph embeddings on a 2-sphere that arise from the normal fans of the two bases.Comment: This paper merges and supersedes the papers arXiv:1101.3050 (of the last two authors) and arXiv:1102.2645 (of the first author

A new genus of Prioninae (Coleoptera, Cerambycidae)

Neoma, a new genus of Cerambycidae (Coleoptera: Cerambycidae: Prioninae: Macrotomini) is described for Mallodonopsis corrosus Bates, 1879, compared to related genera (Aplagiognathus Thomson, 1861; Archodontes Lameere, 1903; and Mallodonopsis Thomson, 1861), and its tribal position discussed. A lectotype for Mallodonopsis corrosus is here designated with the species redescribed and figured

Preference for Skew in Lotteries: Evidence from the Laboratory

Using a laboratory experiment we investigate how skew inuences choices under risk. We find that subjects make significantly riskier choices when the distribution of payoffs is positively skewed, these choices being driven in part by the shape of the utility function but also by subjective distortion of probabilities. A utility model with probability distortion calibrated on laboratory data is able to explain why most gamblers in public lotteries buy only a small number of tickets.risk; skew; gambling; lab experiment

Preference for Skew in Lotteries: Evidence from the Laboratory

Using a laboratory experiment we investigate how skew in uences choices under risk. We find that subjects make significantly riskier choices when the distribution of payoffs is positively skewed, these choices being driven in part by the shape of the utility function but also by subjective distortion of probabilities. A utility model with probability distortion calibrated on laboratory data is able to explain why most gamblers in public lotteries buy only a small number of tickets.Risk; Skew; Gambling; Lab Experiment

On the Nature of “Good” Goods and the Ethical Role of Marketing

The purpose of this essay is to elaborate on an important section of a document titled, Vocation of the Business Leader, published by the Pontifical Council for Justice and Peace. Subtitled “A Reflection,” this document is an 87 paragraph, 13,000 word (in English) statement about the ideals of business leadership as inspired by Christian values and ethics. It was sponsored by Peter K.A. Cardinal Turkson and Bishop Mario Toso in consultation with assorted educators, theologians, economists, and philosophers. The document developed from reflections and discussions on Pope Benedict XVI’s social encyclical Caritas in Veritate, particularly a seminar organized by the Pontifical Council for Justice and Peace in February 2011. As such, it extends Caritas in Veritate, especially with regard to economics and business

Religion-motivated Enterprises in the Marketplace: A Macromarketing Inquiry

This exploratory essay identifies and examines a variety of religiously affiliated or inspired enterprises operating in otherwise secular marketplaces. While explicitly recognizing that some marketplace manifestations of religion can be controversial, even dysfunctional, it argues for the evident macromarketing relevance of this project. The approach for analyzing what this paper refers to as “religion-motivated enterprises” (RMEs) consists of (1) a nominal classification scheme to illustrate and categorize the diversity of RME examples; (2) some foundational principles shared among major faith traditions that provide a basis for an RME ethos; and (3) basic propositions that, with future empirical testing, may explain the contributions of these organizations to improved market performance. Our commentary includes environmental factors that prompted the establishment of many RMEs, the nature of their sustainability, and the importance of mission statements to their operations. Finally, we identify opportunities for additional research and summarize the macromarketing contributions of this article

Enhancing the area of a Raman atom interferometer using a versatile double-diffraction technique

IIn this paper we demonstrate a new scheme for Raman transitions which realize a symmetric momentum-space splitting of $4 \hbar k$, deflecting the atomic wave-packets into the same internal state. Combining the advantages of Raman and Bragg diffraction, we achieve a three pulse state labelled interferometer, intrinsically insensitive to the main systematics and applicable to all kind of atomic sources. This splitting scheme can be extended to $4N \hbar k$ momentum transfer by a multipulse sequence and is implemented on a $8 \hbar k$ interferometer. We demonstrate the area enhancement by measuring inertial forces

Double diffraction in an atomic gravimeter

We demonstrate the realization of a new scheme for cold atom gravimetry based on the use of double diffraction beamsplitters recently demonstrated in \cite{Leveque}, where the use of two retro-reflected Raman beams allows symmetric diffraction in $\pm \hbar k_{eff}$ momenta. Though in principle restricted to the case of zero Doppler shift, for which the two pairs of Raman beams are simultaneously resonant, we demonstrate that such diffraction pulses can remain efficient on atoms with non zero velocity, such as in a gravimeter, when modulating the frequency of one of the two Raman laser sources. We use such pulses to realize an interferometer insensitive to laser phase noise and some of the dominant systematics. This reduces the technical requirements and would allow the realization of a simple atomic gravimeter. We demonstrate a sensitivity of $1.2\times10^{-7}g$ per shot

Hybridizing matter-wave and classical accelerometers

We demonstrate a hybrid accelerometer that benefits from the advantages of both conventional and atomic sensors in terms of bandwidth (DC to 430 Hz) and long term stability. First, the use of a real time correction of the atom interferometer phase by the signal from the classical accelerometer enables to run it at best performances without any isolation platform. Second, a servo-lock of the DC component of the conventional sensor output signal by the atomic one realizes a hybrid sensor. This method paves the way for applications in geophysics and in inertial navigation as it overcomes the main limitation of atomic accelerometers, namely the dead times between consecutive measurements