5,765 research outputs found
Exchange Rate Dynamics and the Overshooting Hypothesis
In this paper we analyze the determinants of the evolution of ex- change rates within the context of alternative models of exchange rate dynamics. We examine the overshooting hypothesis in models which emphasize differential speeds of adjustment in asset and goods markets as well as in models which emphasize portfolio balance considerations. We show that exchange rate overshooting is not an intrinsic characteristic of the foreign exchange market and that it depends on a set of specific assumptions. We also show that the overshooting is not a characteristic of the assumption of perfect foresight nor does it depend in general on the assumption that goods and asset markets clear at different speeds. As long as the speeds of adjustment in the various markets are less than infinite, the key factor determining the short run effects of a monetary expansion is the degree of capital mobility. When capital is highly mobile, the exchange rate overshoots its long-run value and when capital is relatively immobile the exchange rate undershoots its long-run value. Within the context of the portfolio-balance model we show that the effects of a monetary expansion on the dynamics of exchange rates and in particular on whether exchange rates overshoot or undershoot their equilibrium path depend critically on the specification of asset choice, on the degree of substitution among assets, and on the quality of the various assets in being an inflation hedge, Specifically, when internationally traded goods are a better inflation hedge than nontraded goods, the nominal exchange rate overshoots the domestic price level and conversely.
Tethys-Foraminiferen im Münsterländer Kreide-Becken
Aus dem Obercampan von Münster und Umgebung werden neben 5 biostratigraphisch leitenden Foraminiferen noch 9 Arten beschrieben und abgebildet, die bisher in N-Deutschland nur aus der höchsten Oberkreide und dem Dan publiziert worden sind. Viele der letztgenannten Foraminiferen sind in den Ablagerungen der Tethys häufig, sogar in der Oberkreide unterhalb des Maastricht
Using RDF to Model the Structure and Process of Systems
Many systems can be described in terms of networks of discrete elements and
their various relationships to one another. A semantic network, or
multi-relational network, is a directed labeled graph consisting of a
heterogeneous set of entities connected by a heterogeneous set of
relationships. Semantic networks serve as a promising general-purpose modeling
substrate for complex systems. Various standardized formats and tools are now
available to support practical, large-scale semantic network models. First, the
Resource Description Framework (RDF) offers a standardized semantic network
data model that can be further formalized by ontology modeling languages such
as RDF Schema (RDFS) and the Web Ontology Language (OWL). Second, the recent
introduction of highly performant triple-stores (i.e. semantic network
databases) allows semantic network models on the order of edges to be
efficiently stored and manipulated. RDF and its related technologies are
currently used extensively in the domains of computer science, digital library
science, and the biological sciences. This article will provide an introduction
to RDF/RDFS/OWL and an examination of its suitability to model discrete element
complex systems.Comment: International Conference on Complex Systems, Boston MA, October 200
Characterization of dynamical regimes and entanglement sudden death in a microcavity quantum - dot system
The relation between the dynamical regimes (weak and strong coupling) and
entanglement for a dissipative quantum - dot microcavity system is studied. In
the framework of a phenomenological temperature model an analysis in both,
temporal (population dynamics) and frequency domain (photoluminescence) is
carried out in order to identify the associated dynamical behavior. The Wigner
function and concurrence are employed to quantify the entanglement in each
regime. We find that sudden death of entanglement is a typical characteristic
of the strong coupling regime.Comment: To appear in Journal of Physics: Condensed Matte
Light capsules shaped by curvilinear meta-surfaces
We propose a simple yet efficient method for generating in-plane hollow beams
with a nearly-full circular light shell without the contribution of backward
propagating waves. The method relies on modulating the phase in the near field
of a centro-symmetric optical wavefront, such as that from a
high-numericalaperture focused wave field. We illustrate how beam acceleration
may be carried out by using an ultranarrow non-flat meta-surface formed by
engineered plasmonic nanoslits. A mirrorsymmetric, with respect to the optical
axis, circular caustic surface is numerically demonstrated that can be used as
an optical bottle
Design of a Multidirectional Wear Testing Device for Simulating Wear of Biocompatible Materials Used in Joint Implants
In the present work, a novel multidirectional pin-on-disc wear testing device designated CNC-POD (computer-numerical-control pin-on-disc) capable of replicating the cross-shear motions experienced by a prosthesis in vivo was designed and developed in the UTRGV in order to evaluate the wear resistance of new biomaterials. The CNC-POD consists of six temperature-controlled pin-on-disc stations mounted on a two-axis CNC table (X-Y). Each pin-on-disc station is load-programmable up to 510 Newtons (115 pounds). The CNC table allows the machine to reproduce a wide range of 2D patterns in millimeter scale on the six stations under a specific load. Friction force is measured during testing using force sensors and coefficient of friction can be calculated. Motions and loads are fully programmable through LabVIEW
Welfare-Theoretical Analyses of the Brain Drain
The paper reviews and synthesises the theoretical analyses of the brain drain in the earlier literature and in the present symposium in the Journal on the subject. Static analysis and dynamic analysis are distinguished, critical issues are raised relating to how welfare changes should be discussed in the context of migration, and possibilities of fruitful future research are outlined
Landslide Hazard in El Salvador
The destructive seismic events of January 13 (ML: 7.6) and February 13 (ML: 6.1) 2001 in El Salvador, with origin in the subduction area and the volcanic chain, respectively, provide an ideal scenario to analyse the factors that define the landslide hazard in this country. In this paper we analysed the events in terms of strong-motion and precedent climatic condition and their relation with the landslides induced; establishing a great opportunity to compare some hazard assessment methods as those proposed by Mora and Vahrson (1994) and RodrÃguez (2001) which define the hazard in terms of the interaction between triggering agents and susceptibility conditions.
Historically both rainfalls and earthquakes have shown to be important triggers for landslides in El Salvador, and results show how the combination of these factors are also critical in defining trigger thresholds and in controlling failure mechanisms. It was found that the Mora and Vahrson method underestimates the landslides hazard; as was discussed by Bommer and RodrÃguez (2002), this is mainly due to the rainfalls levels used by the method which were defined for the Costa Rica conditions, which are markedly different to those in El Salvador. The RodrÃguez model describes in a better way the landslides hazard, however in some areas the hazard is overestimated due to the way as weighting factors for lithology shades the influence of topography, this suggests that assignment of weighting values in the model must be reviewed implementing a multivariate correspondence analysis instead of the bivariate model used so far
Interactions between dendritic cells and CD4+ T cells during Plasmodium infection
<p>Abstract</p> <p>Background</p> <p>During infection, dendritic cells (DCs) encounter pathogenic microorganisms that can modulate their function and shape the T cell responses generated. During the process of T cell activation, DCs establish strong, long-lasting interactions with naïve T cells.</p> <p>Methods</p> <p>Using a mouse malaria model, the interactions of DCs and naïve CD4<sup>+ </sup>T cells have been analysed.</p> <p>Results</p> <p>DCs, either incubated <it>in vitro </it>with infected erythrocytes or isolated from infected mice, are able to present exogenous antigens by MHC-II, but are not able to establish prolonged effective interactions with naïve CD4<sup>+ </sup>T cells and do not induce T cell activation. It was also found that effective T cell activation of naïve CD4<sup>+ </sup>T cells is impaired during late <it>Plasmodium yoelii </it>infection.</p> <p>Conclusion</p> <p>These data may provide a mechanism for the lack of effective adaptive immune responses induced by the Plasmodium parasite.</p
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