GEOS-3 ocean current investigation using radar altimeter profiling

Both quasi-stationary and dynamic departures from the marine geoid were successfully detected using altitude measurements from the GEOS-3 radar altimeter. The quasi-stationary departures are observed either as elevation changes in single pass profiles across the Gulf Stream or at the crowding of contour lines at the western and northern areas of topographic maps generated using altimeter data spanning one month or longer. Dynamic features such as current meandering and spawned eddies can be monitored by comparing monthly mean maps. Comparison of altimeter inferred eddies with IR detected thermal rings indicates agreement of the two techniques. Estimates of current velocity are made using derived slope estimates in conjunction with the geostrophic equation

The ROCK inhibitor Fasudil prevents chronic restraint stress-induced depressive-like behaviors and dendritic spine loss in rat hippocampus

Indexación: Web of Science; Scopus.Background: Dendritic arbor simplification and dendritic spine loss in the hippocampus, a limbic structure implicated in mood disorders, are assumed to contribute to symptoms of depression. These morphological changes imply modifications in dendritic cytoskeleton. Rho GTPases are regulators of actin dynamics through their effector Rho kinase. We have reported that chronic stress promotes depressive-like behaviors in rats along with dendritic spine loss in apical dendrites of hippocampal pyramidal neurons, changes associated with Rho kinase activation. The present study proposes that the Rho kinase inhibitor Fasudil may prevent the stress-induced behavior and dendritic spine loss. Methods: Adult male Sprague-Dawley rats were injected with saline or Fasudil (i.p., 10 mg/kg) starting 4 days prior to and maintained during the restraint stress procedure (2.5 h/d for 14 days). Nonstressed control animals were injected with saline or Fasudil for 18 days. At 24 hours after treatment, forced swimming test, Golgi-staining, and immuno-western blot were performed. Results: Fasudil prevented stress-induced immobility observed in the forced swimming test. On the other hand, Fasudiltreated control animals showed behavioral patterns similar to those of saline-treated controls. Furthermore, we observed that stress induced an increase in the phosphorylation of MYPT1 in the hippocampus, an exclusive target of Rho kinase. This change was accompanied by dendritic spine loss of apical dendrites of pyramidal hippocampal neurons. Interestingly, increased pMYPT1 levels and spine loss were both prevented by Fasudil administration. Conclusion: Our findings suggest that Fasudil may prevent the development of abnormal behavior and spine loss induced by chronic stress by blocking Rho kinase activity.https://academic.oup.com/ijnp/article/20/4/336/263217

The Changing Role of Global Financial Brands in the Underwriting of Foreign Government Debt (1815-2010)

This paper covers the long-term evolution of the primary market for foreign government debt. We discuss the role of financial intermediaries as underwriters and distributors of securities, providers of information, and lending of last resort services since the early 19th century, and the evolution of this role. We underscore the role of the prestige of global financial brands in sustaining early foreign debt markets and its weakening in the modern era.Sovereign debt, primary bond market, reputation, underwriting, certification, information asymmetries, investment banking, credit rating agencies, IMF

Hamiltonian description of singular Lagrangian systems with spontaneously broken time translation symmetry

Shapere and Wilczek recently found some singular Lagrangian systems which spontaneously breaks time translation symmetry. The common feature of their models is that the energy functions are multivalued in terms of the canonical phase space variables and the symmetry breaking ground states are all located at the brunching point singularities. By enlarging the phase space and making use of Dirac's theory on constrained Hamiltonian systems, we present the Hamiltonian description of some of the models discussed by Shapere and Wilczek and found that both the multivaluedness and the brunching point singularities can be avoided, while the spontaneous breaking oftime translation becomes more transparent. It is also shown that the breaking of time translation is always accompanied by the breaking of time reversal.Comment: 13 page

COLA. III. Radio Detection of Active Galactic Nucleus in Compact Moderate Luminosity Infrared Galaxies

We present results from 4.8 GHz Very Large Array (VLA) and global very long baseline interferometry (VLBI) observations of the northern half of the moderate FIR luminosity (median L_(IR) = 10^(11.01) L_☉) COLA sample of star-forming galaxies. VLBI sources are detected in a high fraction (20/90) of the galaxies observed. The radio luminosities of these cores (~10^(21) W Hz^(–1)) are too large to be explained by radio supernovae or supernova remnants and we argue that they are instead powered by active galactic nuclei (AGNs). These sub-parsec scale radio cores are preferentially detected toward galaxies whose VLA maps show bright 100-500 parsec scale nuclear radio components. Since these latter structures tightly follow the FIR to radio-continuum correlation for star formation, we conclude that the AGN-powered VLBI sources are associated with compact nuclear starburst environments. The implications for possible starburst-AGN connections are discussed. The detected VLBI sources have a relatively narrow range of radio luminosity consistent with models in which intense compact Eddington-limited starbursts regulate the gas supply onto a central supermassive black hole. The high incidence of AGN radio cores in compact starbursts suggests little or no delay between the starburst phase and the onset of AGN activity

Renewable energy research progress in Mexico: a review

Mexico ranks 9th in the world in crude oil reserves, 4th in natural gas reserves in America and it is also highly rich in renewable energy sources (solar, wind, biomasss, hydropower and geothermal). However, the potential of this type of energy has not been fully exploited. Hydropower is the renewable energy source with the highest installed capacity within the country (11,603 MW), while geothermal power capacity (958 MW) makes Mexico to be ranked 4th in the use of this energy worldwide. Wind energy potential is concentrated in five different zones, mainly in the state of Oaxaca, and solar energy has a high potential due to Mexico's ideal location in the so called Solar Belt. Biomass energy has the highest potential (2635 to 3771 PJ/year) and has been the subject of the highest number of research publications in the country during the last 30 years (1982-2012). Universidad Nacional Autonoma de Mexico has led research publications in hydropower, wind, solar and biomass energy and Instituto de Investigaciones Electricas in geothermal energy during this period. According to the General Law for Climate Change the country has set the goal of generating 35% of its energy needs from renewable sources by 2024. This paper presents an overview of the renewable energy options available in Mexico, current status, main positive results to date and future potential. It also analyses barriers hindering improvements and proposes pertinent solutions. © 2014 The Authors

Effects of clinical experience in the nursing student attitudes toward people with psychiatric disabilities

Indexación: Scopus; Scielo.En la formación del estudiante de pregrado de Enfermería se hace fundamental la elección de experiencias de aprendizaje significativas. Objetivo: Determinar el efecto de la experiencia clínica en servicios de psiquiatría, en las actitudes de estudiantes de Enfermería hacia las personas con discapacidad psiquiátrica. Material y método: Diseño cuasi experimental de pre y postest. La muestra incluyó un total de 84 estudiantes de Enfermería de tercer año de dos universidades de Santiago de Chile. El total de la muestra completó la "Escala de Actitudes hacia las Personas con Discapacidad" (EAPD) forma G. Se consideró como intervención las estrategias usadas en las asignaturas clínicas de enfermería psiquiátrica en ambas universidades. Se realizó prueba t de student para muestras relacionadas. Resultados: Se encontró diferencia estadísticamente significativa (p< 0,05) en el postest, lo que está relacionado con las experiencias de aprendizaje que consideran el contacto con personas con discapacidad psiquiátrica, en diferentes dispositivos de la red de psiquiatría y el acompañamiento docente directo. Conclusión: Estos hallazgos validan la importancia de la elección de experiencias clínicas, en los currículos de formación de Enfermería, como instancias que disminuyen las actitudes negativas como la estigmatización.The choice of meaningful learning experiences becomes essential in basic Nursing education programs. The purpose of this study is to determine the effect of clinical experience in psychiatric services in Nursing students' attitudes towards people with mental illnesses. A quasi-experimental design method of pre-test and post-test was used. The sample was made up of 84 third-year-nursing students from two universities in Santiago, Chile. All of the participants completed the Scale of Attitudes Toward Disabled Persons (SADP)-G. The strategies used in subjects of psychiatric nursing at both universities were regarded as intervention. Student t test for related samples was performed. Results: Respondents reported statistically significant difference (p <0.05) in the post test, which is associated with learning experiences that consider contact with people with mental illness in any of the different psychiatry network nodes and direct educational support. Conclusion: Validate the importance of including the clinical experience in the nursing training curriculum as a way of reducing negative attitudes of Nursing students, such as stigmatization, towards people with mental illnesses.https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0717-95532017000300125&lng=en&nrm=iso&tlng=e