3,126 research outputs found
NONLINEAR MONETARY POLICY RULES: SOME NEW EVIDENCE FOR THE US
This paper dreives optimal monetary policy rules in setups where certainty equivalence does not hold because either central bank preferences are not quadratic, and/or the aggregate supply relation is nonlinear. Analytical results show that these features lead to sign and size aymmetries, and nonlinearities in the policy rule. Reduced-form estimates indicate that US monetary policy can be characterized by a nonlinear policy rule after 1983, but not before 1979. This finding is consistent with the view that the Fed`s inflation preferences during the Volcker-Greenspan regime differ considerably from the ones during the Burns-Miller regime.
Technologies for the marketplace from the Centers for Disease Control
The Centers for Disease Control, a Public Health Service agency, is responsible for the prevention and control of disease and injury. Programs range from surveillance and prevention of chronic and infectious diseases to occupational health and injury control. These programs have produced technologies in a variety of fields, including vaccine development, new methods of disease diagnosis, and new tools to ensure a safer work environment
Heritage Stone 1. Repair and Maintenance of Natural Stone in Historical Structures: The Potential Role of the IUGS Global Heritage Stone Initiative
Natural stone has been used for millennia in many historically and culturally important structures. It inevitably undergoes weathering from natural processes and damage from human activities. Deterioration affects both ornamental features and main structural members of constructions, ultimately requiring repair and maintenance, or causing loss of the structure altogether. Stone similar to the original should generally be used for repairs, but if that is impossible a closely similar material is required. Use of inappropriate stone or treatment with incompatible mortars can be aesthetically unsightly or have structurally and financially damaging consequences. Such use typically arises because of a lack of information and awareness among commissioners and specifiers of works, along with budget constraints leading to selection of cheaper alternatives. Even some World Heritage Sites have suffered. Selected examples from Western Europe illustrate these problems. The Global Heritage Stone initiative has been launched to improve recognition of the internationally most important heritage stones, promote their proper use in construction, maintenance and repair, and to stress the need to safeguard important stone resources for future use.RÉSUMÉLa pierre naturelle a été utilisée depuis des millénaires dans de nombreuses structures importantes historiquement et culturellement. Inévitablement cette pierre s’altère sous l’effet de processus naturels et de dommages causés par les activités humaines. Cette détérioration affecte aussi bien les éléments ornementaux que les principaux éléments structuraux des constructions, ce qui, éventuellement nécessite réparation et entretien, ou alors peut entraîner la perte de la structure. Une pierre semblable à l'originale doit généralement être utilisée pour des réparations, ou alors un matériau très similaire est requis. L’utilisation d’une pierre inappropriée ou un traitement avec des mortiers incompatibles peut être esthétiquement disgracieux ou avoir des conséquences structurellement et financièrement préjudiciables. Cette utilisation erronée est typiquement le résultat d’un manque d'information et de sensibilisation des commissaires et des rédacteurs du cahier des charges, ainsi que de contraintes budgétaires conduisant au choix d’options moins coûteuses. Et même, certains sites du patrimoine mondial en ont souffert. Des exemples choisis de l'Europe de l’ouest illustrent ces problèmes. L'initiative du patrimoine mondial de la pierre de taille lancée pour améliorer la conscience à l'échelle internationale des principales pierres du patrimoine, promouvoir leur utilisation correcte dans la construction, leur entretien et leur réparation, et souligner la nécessité de préserver les ressources importantes en pierre pour les besoins à venir.                                               Traduit par le Traducteu
Towards an automatic monitoring for higher education learning design
The development of new Information Technologies (IT) has originated new possibilities to design pedagogical methodologies that provide the necessary knowledge and skills in the higher education. This paper presents a metadata-based model representation that is used to represent, detect, and even automatically correct possible pitfalls in the schedule process of a Learning Design (LD) in e-learning environments. This metadata-based model is combined with Artificial Intelligence techniques, such as, planning and scheduling to monitor how is evolving a particular LD, and to propose solutions in those modules of the design that learning problems among the students have been found.This work was funded by the Universidad de Alcalá
project UAH PI2005/084 and the CICYT project TSI2006-
12085
The role of MYC and PP2A in the initiation and progression of myeloid leukemias
The MYC transcription factor is one of the best characterized PP2A substrates. Deregulation of the MYC oncogene, along with inactivation of PP2A, are two frequent events in cancer. Both proteins are essential regulators of cell proliferation, apoptosis, and differentiation, and they, directly and indirectly, regulate each other's activity. Studies in cancer suggest that targeting the MYC/PP2A network is an achievable strategy for the clinic. Here, we focus on and discuss the role of MYC and PP2A in myeloid leukemias
Confined photon modes with triangular symmetry in hexagonal microcavities in 2D photonic Crystals
We present theoretical and experimental studies of the size and thickness
dependencies of the optical emission spectra from microcavities with hexagonal
shape in films of two-dimensional photonic crystal. A semiclassical plane-wave
model, which takes into account the electrodynamic properties of quasi-2D
planar photonic microcavity, is developed to predict the eigenfrequencies of
the confined photon modes as a function of both the hexagon-cavity size and the
film thickness. Modes with two different symmetries, triangular and hexagonal,
are critically analyzed. It is shown that the model of confined photon modes
with triangular symmetry gives a better agreement between the predicted
eigenmodes and the observed resonances.Comment: 14 pages, 6 figure
Nonlinear Monetary Policy Rules: Some New Evidence for the U.S.
This paper derives optimal monetary policy rules in setups where certainty equivalence does not hold because either central bank preferences are not quadratic, and/or the aggregate supply relation is nonlinear. Analytical results show that these features lead to sign and size asymmetries, and nonlinearities in the policy rule. Reduced-form estimates indicate that US monetary policy can be characterized by a nonlinear policy rule after 1983, but not before 1979. This finding is consistent with the view that the Fed's inflation preferences during the Volcker-Greenspan regime differ considerably from the ones during the Burns-Miller regime.Dans cet article, nous dérivons les règles de politique monétaire optimales dans des cadres où \"l'équivalence certaine\" n'est pas satisfaite. On trouve des cas de ce type lorsque, par exemple, les préférences de la banque centrale ne sont pas quadratiques ou lorsque la relation d'offre agrégée n'est pas linéaire. Les résultats théoriques semblent montrer qu'ils peuvent conduire à des asymétries de signe et de niveau et à des nonlinéarités dans la règle de politique. À partir d'estimations de la forme réduite sur données américaines, nous trouvons que la politique monétaire des États-Unis peut être caractérisée par une règle décisionnelle non linéaire après 1983, mais que ce n'est pas le cas avant 1979. Ces résultats reflètent bien la nette différence d'attitude de la Réserve Fédérale face à l'inflation durant les périodes Volcker-Greenspan et Burns-Miller
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