Interpolating fields of carbon monoxide data using a hybrid statistical-physical model

Atmospheric Carbon Monoxide (CO) provides a window on the chemistry of the atmosphere since it is one of few chemical constituents that can be remotely sensed, and it can be used to determine budgets of other greenhouse gases such as ozone and OH radicals. Remote sensing platforms in geostationary Earth orbit will soon provide regional observations of CO at several vertical layers with high spatial and temporal resolution. However, cloudy locations cannot be observed and estimates of the complete CO concentration fields have to be estimated based on the cloud-free observations. The current state-of-the-art solution of this interpolation problem is to combine cloud-free observations with prior information, computed by a deterministic physical model, which might introduce uncertainties that do not derive from data. While sharing features with the physical model, this paper suggests a Bayesian hierarchical model to estimate the complete CO concentration fields. The paper also provides a direct comparison to state-of-the-art methods. To our knowledge, such a model and comparison have not been considered before.Comment: Published in at http://dx.doi.org/10.1214/08-AOAS168 the Annals of Applied Statistics (http://www.imstat.org/aoas/) by the Institute of Mathematical Statistics (http://www.imstat.org

Sensitivity of nucleon-nucleus scattering to the off-shell behavior of on-shell equivalent NN potentials

The sensitivity of nucleon-nucleus elastic scattering to the off-shell behavior of realistic nucleon-nucleon interactions is investigated when on-shell equivalent nucleon-nucleon potentials are used. The study is based on applications of the full-folding optical model potential for an explicit treatment of the off-shell behavior of the nucleon-nucleon effective interaction. Applications were made at beam energies between 40 and 500 MeV for proton scattering from 40Ca and 208Pb. We use the momentum-dependent Paris potential and its local on-shell equivalent as obtained with the Gelfand-Levitan and Marchenko inversion formalism for the two nucleon Schroedinger equation. Full-folding calculations for nucleon-nucleus scattering show small fluctuations in the corresponding observables. This implies that off-shell features of the NN interaction cannot be unambiguously identified with these processes. Inversion potentials were also constructed directly from NN phase-shift data (SM94) in the 0-1.3 GeV energy range. Their use in proton-nucleus scattering above 200 MeV provide a superior description of the observables relative to those obtained from current realistic NN potentials. Limitations and scope of our findings are presented and discussed.Comment: 17 pages tightened REVTeX, 8 .ps figures, submitted to Phys. Rev.

Energy Dependence of the NN t-matrix in the Optical Potential for Elastic Nucleon-Nucleus Scattering

The influence of the energy dependence of the free NN t-matrix on the optical potential of nucleon-nucleus elastic scattering is investigated within the context of a full-folding model based on the impulse approximation. The treatment of the pole structure of the NN t-matrix, which has to be taken into account when integrating to negative energies is described in detail. We calculate proton-nucleus elastic scattering observables for $^{16}$O, $^{40}$Ca, and $^{208}$Pb between 65 and 200 MeV laboratory energy and study the effect of the energy dependence of the NN t-matrix. We compare this result with experiment and with calculations where the center-of-mass energy of the NN t-matrix is fixed at half the projectile energy. It is found that around 200 MeV the fixed energy approximation is a very good representation of the full calculation, however deviations occur when going to lower energies (65 MeV).Comment: 11 pages (revtex), 6 postscript figure

Underidentification?

We study the identification of an econometric model that is linear in parameters from a generalized-method-of-moments perspective. We regard underidentification as a set of over- identifying restrictions imposed on an augmented structural model. Therefore, our proposal is to test for underidentification by testing for overidentification in the augmented model using standard methods that are available in the literature. As examples we consider intertemporal asset pricing and dynamic panel data models.

Estrategias de redes de apoyo en el proceso de inserción laboral por parte de mujeres en condición sola con hijos(as) menores de 12 años de edad, pertenecientes a la escuela Enrique Cárdenas, Reñaca Alto, Viña del Mar

Tesis (Trabajo Social)Este proyecto de investigación trata sobre las redes de apoyo que articulan las madres en condición sola con hijos dependientes menores de 12 años, para permitir su inserción laboral. Específicamente se analiza la forma cómo se estructuran las redes de acuerdo a sus diferentes categorías como las redes familiares, de amistades y gubernamentales principalmente. Se encontró que en Chile estas mujeres reciben importantes ayudas para cumplir con sus diferentes roles como madres jefas de hogar de parte de los programas de gobierno, lo que se complementa con la gestión que cada una desarrolla de modo personal, lo que resulta muy importante para garantizar el bienestar y la calidad de vida de su familia. Al respecto se ha observado que estas madres en situación sola si reciben colaboración de las diferentes redes, lo cual implica que ellas deben saber tomar decisiones para elegir lo más conveniente, dada su condición particular de vulnerabilidad al carecer de la compañía del padre de sus hijos y de recursos económicos suficientes. Por este motivo deben orientar, sostener y articular sus redes de apoyo familiar, comunitario e institucional facilitando su participación en el mercado laboral. Actualmente en Chile existe un aumento en la inserción laboral femenina general, sin embargo también se presenta una fuerte exclusión del mercado laboral de los segmentos menos calificados, por lo cual se ven obligadas a desarrollar diferentes actividades en el mercado informal, en este contexto cada red cumple con una función específica para contribuir al desarrollo de este tipo de familia