Dynamics of Carroll Strings

We construct the canonical action of a Carroll string doing the Carroll limit of a canonical relativistic string. We also study the Killing symmetries of the Carroll string, which close under an infinite dimensional algebra. The tensionless limit and the Carroll $p$-brane action are also discussed.Comment: Footnote and references adde

A comparative study of non-Gaussianity in ILC-7yr CMB map

A detection or non detection of primordial non--Gaussianity (NG) by using the cosmic microwave background radiation (CMB) is a possible way to break the degeneracy of early universe models. Since a single statistical estimator hardly can be sensitive to all possible forms of NG which may be present in the data, it is important to use different statistical estimators to study NG in CMB. Recently, two new large-angle NG indicators based on skewness and kurtosis of spherical caps or spherical cells of CMB sky have been proposed and used in both CMB data and simulated maps. Here, we make a comparative study of these two different procedures by examining the NG in the WMAP seven years ILC map. We show that the spherical cells procedure detects a higher level of NG than that obtained by the method with overlapping spherical caps.Comment: 8 pages, 3 figures; V2: Typos correcte

Strategy Options for Disaster Risk Reduction Through Institutional Improvements and Enhanced Financial Sustainability: Recommendations

This presentation was commissioned by the Natural Disaster Network of the Regional Policy Dialogue for the V Hemispheric Meeting celebrated on June 13th and 14th, 2005.Disasters, Management Network Gestión de la Red

State and Origin Branding in Hispanic Food Markets

Evaluations on the effectiveness of state and origin branding programs remain relatively scant and generally have not focused on specific target populations, including Hispanic consumers, the fastest-growing group. This study evaluates the effectiveness of the Arizona Grown brand and the nascent Mexico Selected Quality brand in differentiating and promoting food products in Hispanic markets. It was found that Hispanic consumers tend to view these food-product brands as nearly identical in perceived quality. Furthermore, they are willing to pay nearly equal premiums for products branded as such. These consumers saw no value in country-of-origin information alone.Agribusiness,

Influence of social and work exchange relationships on organizational citizenship behavior, The

Previous studies explain situational antecedents of OCB using social exchange theory. However, the effects of factors such as perceptions of job characteristics on OCB seem to require a different explanatory mechanism. We propose that these effects can be explained through a new exchange relationship that we call work exchange. We develop a theory for the situational antecedents of OCB that includes economic, work, and social exchange relationships. The theory is tested using structural equations.exchange relationship; organizational citizenship behavior; organizational commitment; perceived organizational support; job characteristics;

Anomalies of the infrared-active phonons in underdoped YBCO as an evidence for the intra-bilayer Josephson effect

The spectra of the far-infrared c-axis conductivity of underdoped YBCO crystals exhibit dramatic changes of some of the phonon peaks when going from the normal to the superconducting state. We show that the most striking of these anomalies can be naturally explained by changes of the local fields acting on the ions arising from the onset of inter- and intra-bilayer Josephson effects.Comment: Revtex, epsf, 6 pages, 3 figures encapsulated in tex

The changing incentive structure of institutional asset managers: implications for financial markets.

This article presents the principal findings of the Working Group on Incentive Structures in Institutional Asset Management set up under the aegis of the Commitee on the Global Financial System (CGFS). These findings, which have recently been published in a report, aim to give the central bank community – and beyond that, the financial community – a better understanding of ongoing developments in the fund management industry and their potential implications for financial markets. The report, based on a comprehensive literature review and extensive interviews with market practitioners, has identified various features and trends in the industry with a potential effect on the functioning of financial markets. However, as many of these effects are at least partially offsetting, the lack of reliable empirical evidence has not allowed the working group to come to a clear-cut conclusion on the aggregate effect of these various features and trends at the current juncture. Still, one broad conclusion may be drawn from this report: ongoing and future developments in the fund management industry have the potential to change institutional behaviour in ways that can be important for financial markets. This relates to the general issue of preserving the diversity of investment behaviour, and partially results from the fact that parts of the institutional asset management industry have moved towards becoming a «commodity» industry offering investors more and more standardised investments products and approaches. Therefore, developments in the industry may require further attention by the financial community as a whole. More specifically, the report points to four broad areas where particular attention should be paid: risk management and disclosure, conflicts of interest, explicit and implicit barriers to market entry, and regulatory trade-offs.

Structured learning of assignment models for neuron reconstruction to minimize topological errors

© 20xx IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.Structured learning provides a powerful framework for empirical risk minimization on the predictions of structured models. It allows end-to-end learning of model parameters to minimize an application specific loss function. This framework is particularly well suited for discrete optimization models that are used for neuron reconstruction from anisotropic electron microscopy (EM) volumes. However, current methods are still learning unary potentials by training a classifier that is agnostic about the model it is used in. We believe the reason for that lies in the difficulties of (1) finding a representative training sample, and (2) designing an application specific loss function that captures the quality of a proposed solution. In this paper, we show how to find a representative training sample from human generated ground truth, and propose a loss function that is suitable to minimize topological errors in the reconstruction. We compare different training methods on two challenging EM-datasets. Our structured learning approach shows consistently higher reconstruction accuracy than other current learning methods.Peer ReviewedPostprint (author's final draft

Anharmonic Self-Energy of Phonons: Ab Initio Calculations and Neutron Spin Echo Measurements

We have calculated (ab initio) and measured (by spin-echo techniques) the anharmonic self-energy of phonons at the X-point of the Brillouin zone for isotopically pure germanium. The real part agrees with former, less accurate, high temperature data obtained by inelastic neutron scattering on natural germanium. For the imaginary part our results provide evidence that transverse acoustic phonons at the X-point are very long lived at low temperatures, i.e. their probability of decay approaches zero, as a consequence of an unusual decay mechanism allowed by energy conservation.Comment: 8 pages, 2 figures, pdf fil