At Face Value: Visual Antecedents of Impression Formation in Servicescapes

Consumers may base employee impressions on physical appearance\ud and displayed personal objects. In a scenario experiment,\ud using photos of a physician and a 360-degree panorama of his\ud consultation room, we examined the effects of appearance and\ud tangibles on impression formation. Study 1 shows that observers\ud employ various strategies of combining information from different\ud sources when forming an impression of the employee’s friendliness\ud and competence. Whereas previous research has shown that impression\ud formation based on personal appearances proceeds in an\ud automatic fashion, the findings of study 2 indicate that impression\ud formation grounded in the perception of tangibles requires more\ud elaborate processin

Measurement of Permanent Electric Dipole Moments of Charged Hadrons in Storage Rings

Permanent Electric Dipole Moments (EDMs) of elementary particles violate two fundamental symmetries: time reversal invariance (T) and parity (P). Assuming the CPT theorem this implies CP-violation. The CP-violation of the Standard Model is orders of magnitude too small to be observed experimentally in EDMs in the foreseeable future. It is also way too small to explain the asymmetry in abundance of matter and anti-matter in our universe. Hence, other mechanisms of CP violation outside the realm of the Standard Model are searched for and could result in measurable EDMs. Up to now most of the EDM measurements were done with neutral particles. With new techniques it is now possible to perform dedicated EDM experiments with charged hadrons at storage rings where polarized particles are exposed to an electric field. If an EDM exists the spin vector will experience a torque resulting in change of the original spin direction which can be determined with the help of a polarimeter. Although the principle of the measurement is simple, the smallness of the expected effect makes this a challenging experiment requiring new developments in various experimental areas. Complementary efforts to measure EDMs of proton, deuteron and light nuclei are pursued at Brookhaven National Laboratory and at Forschungszentrum Juelich with an ultimate goal to reach a sensitivity of 10^{-29} e cm.Comment: 8 pages, 2 figure

Truthful Mechanisms for Matching and Clustering in an Ordinal World

We study truthful mechanisms for matching and related problems in a partial information setting, where the agents' true utilities are hidden, and the algorithm only has access to ordinal preference information. Our model is motivated by the fact that in many settings, agents cannot express the numerical values of their utility for different outcomes, but are still able to rank the outcomes in their order of preference. Specifically, we study problems where the ground truth exists in the form of a weighted graph of agent utilities, but the algorithm can only elicit the agents' private information in the form of a preference ordering for each agent induced by the underlying weights. Against this backdrop, we design truthful algorithms to approximate the true optimum solution with respect to the hidden weights. Our techniques yield universally truthful algorithms for a number of graph problems: a 1.76-approximation algorithm for Max-Weight Matching, 2-approximation algorithm for Max k-matching, a 6-approximation algorithm for Densest k-subgraph, and a 2-approximation algorithm for Max Traveling Salesman as long as the hidden weights constitute a metric. We also provide improved approximation algorithms for such problems when the agents are not able to lie about their preferences. Our results are the first non-trivial truthful approximation algorithms for these problems, and indicate that in many situations, we can design robust algorithms even when the agents may lie and only provide ordinal information instead of precise utilities.Comment: To appear in the Proceedings of WINE 201

Steps in the bacterial flagellar motor

The bacterial flagellar motor is a highly efficient rotary machine used by many bacteria to propel themselves. It has recently been shown that at low speeds its rotation proceeds in steps [Sowa et al. (2005) Nature 437, 916--919]. Here we propose a simple physical model that accounts for this stepping behavior as a random walk in a tilted corrugated potential that combines torque and contact forces. We argue that the absolute angular position of the rotor is crucial for understanding step properties, and show this hypothesis to be consistent with the available data, in particular the observation that backward steps are smaller on average than forward steps. Our model also predicts a sublinear torque-speed relationship at low torque, and a peak in rotor diffusion as a function of torque

What Firms' Surveys Tell Us about Price-Setting Behavior in the Euro Area

This study investigates the pricing behavior of firms in the euro area on the basis of surveys conducted by nine Eurosystem national central banks, covering more than 11,000 firms. The results, consistent across countries, show that firms operate in monopolistically competitive markets, where prices are mostly set following markup rules and where price discrimination is common. Around one-third of firms follow mainly timedependent pricing rules, while two-thirds allow for elements of state dependence. The majority of the firms take into account both past and expected economic developments in their pricing decisions. Price reviews happen with a low frequency, of about one to three times per year in most countries, but prices are actually changed even less. Hence, price stickiness arises at both stages of the price-setting process and is mainly driven by customer relationships — explicit and implicit contracts — and coordination failure. Firms adjust prices asymmetrically in response to shocks: while cost shocks have a greater impact when prices have to be raised than when they have to be reduced, a fall in demand is more likely to induce a price change than an increase in demand

The pricing behaviour of firms in the euro area: new survey evidence

This study investigates the pricing behaviour of firms in the euro area on the basis of surveys conducted by nine Eurosystem national central banks, covering more than 11,000 firms. The results, robust across countries, show that firms operate in monopolistically competitive markets, where prices are mostly set following markup rules and where price discrimination is common. Around one-third of firms follow mainly time-dependent pricing rules while twothirds allow for elements of state-dependence. The majority of firms take into account past and expected economic developments in their pricing decisions. Price stickiness is mainly driven by customer relationships – explicit and implicit contracts – and coordination failure. Firms adjust prices asymmetrically in response to shocks: while cost shocks have a greater impact when prices have to be raised than when they have to be reduced, reductions in demand are more likely to induce a price change than increases in demand. JEL Classification: E30, D40Inflation persistence, nominal rigidity, price setting, real rigidity, survey data

Impact of the Specific Mutation in KRAS Codon 12 Mutated Tumors on Treatment Efficacy in Patients with Metastatic Colorectal Cancer Receiving Cetuximab-Based First-Line Therapy: A Pooled Analysis of Three Trials

Purpose: This study investigated the impact of specific mutations in codon 12 of the Kirsten-ras (KRAS) gene on treatment efficacy in patients with metastatic colorectal cancer (mCRC). Patients: Overall, 119 patients bearing a KRAS mutation in codon 12 were evaluated. All patients received cetuximab-based first-line chemotherapy within the Central European Cooperative Oncology Group (CECOG), AIO KRK-0104 or AIO KRK-0306 trials. Results: Patients with KRAS codon 12 mutant mCRC showed a broad range of outcome when treated with cetuximab-based first-line regimens. Patients with tumors bearing a KRAS p.G12D mutation showed a strong trend to a more favorable outcome compared to other mutations (overall survival 23.3 vs. 14-18 months; hazard ratio 0.66, range 0.43-1.03). An interaction model illustrated that KRAS p.G12C was associated with unfavorable outcome when treated with oxaliplatin plus cetuximab. Conclusion: The present analysis suggests that KRAS codon 12 mutation may not represent a homogeneous entity in mCRC when treated with cetuximab-based first-line therapy. Copyright (C) 2012 S. Karger AG, Base