Errors in kinematic distances and our image of the Milky Way Galaxy

Errors in the kinematic distances, under the assumption of circular gas orbits, were estimated by performing synthetic observations of a model disk galaxy. It was found that the error is < 0.5 kpc for most of the disk when the measured rotation curve was used, but larger if the real rotation curve is applied. In both cases, the error is significantly larger at the positions of the spiral arms. The error structure is such that, when kinematic distances are used to develope a picture of the large scale density distribution, the most significant features of the numerical model are significantly distorted or absent, while spurious structure appears. By considering the full velocity field in the calculation of the kinematic distances, most of the original density structures can be recovered.Comment: Accepted for publication in A

Electrochemical and structural characterization of sulfonated polysulfone

We describe the synthesis, as well as the electrochemical and structural characterization, of sulfonated polysulfone intended for use in PEM fuel cells. Starting from a commercial polysulfone, we assessed the performance of these prepared ionomers using synthesis protocols compatible with industrial production. The efficiency of the trimethylsilyl chlorosulfonate and chlorosulfonic acid reagents in the sulfonation process was confirmed by H-1 NMR, FTIR, elemental analysis, chemical titration and thermal analysis (DSC and TGA). Chlorosulfonic acid was the most effective sulfonation reagent. However, based on SEC-MALLS, this reagent induced degradation of the backbone that is detrimental to the thermomechanical stability and lifespan of the membranes. The electrical characterization of the membranes was undertaken using impedance spectroscopy in contact with different HCl aqueous solutions at various temperatures. The activation energies, which ranged from 8.2 to 11 kJ/mol, were in agreement with the prevailing proton vehicular mechanism. (C) 2015 Elsevier Ltd. All rights reserved.This study was supported by the Ministry of Science and lnnovation with a project MAT2013 46452 C4 3 R and the Regional Program MATERYENER3CM S2013/MIT 2753 of the Community of Madrid. J Y Sanchez also wishes to thank "Catedras de Excelencia" of Universidad Carlos III de Madrid for providing a grant. A.M. Martos wishes to thank the mobility grant of Universidad Carlos III de Madrid

On the intriguing subject of the low amplitudes of magnetic anomalies at the Powell Basin

The Powell Basin is a small oceanic basin bounded by continental blocks that fragmented during break up of Antarctica from South America. This basin bounds the South Orkney Microcontinent to the east, the South Scotia Ridge to the north, and the Antarctic Peninsula to the west. The timing of its opening is poorly constrained due to the low amplitude of the oceanic spreading magnetic anomalies which hampers their identification and interpretation causing large uncertainties in proposed ages that range from the Late Eocene to Early Miocene. This basin has been extensively studied using a variety of geophysical methods including seismic, gravity and magnetics surveys intended to unveil the tectonic domains, the particularities of its magnetic anomalies and the understanding of the thermal regime in this area. Here, we show new magnetic and heat flow data integrated with other geophysical data from international databases (multichannel seismic data, bathymetry and free-air gravity), to analyze the thermal structure of the lithosphere of Powell Basin and the upper mantle dynamics as well as to discuss the probable causes of the abnormally small amplitudes of its magnetic anomalies. Our results show that the low magnetic anomaly amplitudes are not widespread but concentrate in the eastern and southwestern part of the basin. We propose that these small amplitudes result from the thermal dependency of magnetic rocks caused by an asthenospheric branch flow that penetrates the Powell Basin through the northern area

Technical and economical study of two tropical leguminous forages to feed dairy cows in the NW region of Dominican Republic

Two tropical leguminous forages are used as a partial substitute of the concentrate feed to milk production and its viability in the Northwest region of Dominican Republic is studied. Twelve dairy cows are used (crosses between Holstein and Brown Swiss and Jersey) in a fully random experimental design, with three treatments and four repetitions. In treatment I feed supplementation was 8 kg of concentrate per cow and day; while, in treatment II animals were fed with 4 kg of concentrate and 5 kg DM of leguminous forages. Treatment III supplementation was 4 kg of concentrate and a grass-leguminous forage mixture ad libitum. The experiment was carried out during 10 weeks and an individual milk production control was realised every day during this time. Results don"t show significant differences (p³0,05) for individual production neither accumulated one respecting the three proposed treatments. The study of gross margin according to treatment don’t show significant differences (p³0,05). However, simulation analysis of scenes for treatment I shows a high sensibility to modify the price of variable factor (concentrate). On the other hand, the treatment II showed superior margin and high stability to the price variation for inputs and outputs, and so was the treatment of choice in all the scenes simulated independently of milk and concentrate prices.Se estudió la utilización de leguminosas forrajeras tropicales como sustitutivo parcial del concentrado en la producción lechera y su viabilidad en la región noroeste de la República Dominicana. Se utilizan 12 vacas lecheras (cruces de Holstein con Pardo Suizo y Jersey) en un diseño experimental aleatorio con tres tratamientos y cuatro repeticiones. En el tratamiento I se suplementa con 8 kg de concentrado por vaca y día; en tanto que, en el tratamiento II se suplementan con 4 kg de concentrado y 5 kg de materia seca (MS) de una leguminosa forrajera tropical. En el tratamiento III se aporta una suplementación de 4 kg de concentrado y una asociación de una gramínea y otra leguminosa tropical ad libitum. La experiencia se desarrolló durante 10 semanas y cada día se realizó el control lechero individual. Los resultados muestran la ausencia de diferencias significativas (p³0,05) en la producción individual y acumulada respecto a los tres tratamientos propuestos. Al enfrentar el margen bruto respecto al tratamiento no se observan diferencias significativas (p³0,05). No obstante el análisis de simulación de escenarios muestra que el tratamiento I es muy sensible a la modificación del precio del factor variable (concentrado). Por otro lado, el tratamiento II presenta margen superior y alta estabilidad ante la variación de los precios de los insumos/productos y se muestra como tratamiento de elección en todos los escenarios simulados independientemente de los precios de la leche y el concentrado

Peligro nacional : estudios é impresiones sobre el catanalismo

Copia digital. España : Ministerio de Cultura y Deporte. Subdirección General de Coordinación bibliotecaria, 201

Investigación cuantitativa y cualitativa. Los estudios de usos y motivaciones culturales por cantes de ida y vuelta

Esta aportación se presenta como un nexo que vincula y da continuidad a las actividades de investigación relacionadas con diversos aspectos del comportamiento de consumo cultural universitario que se vienen realizando desde el Observatorio Cultural del Proyecto Atalaya. En concreto, los estudios revisados son los que se agrupan bajo la denominación genérica Proyecto USOS; así como, el que lleva por título Estudio cualitativo de motivaciones culturales de los estudiantes universitarios; que se encuentra actualmente en período de ejecución. Dada la complejidad inherente al comportamiento de consumo cultural y a las distintas facetas que pueden estar implicadas en el mismo, argumentamos en pro de la conveniencia de partir de metodologías cuantitativas y cualitativas que permitan enriquecer el conocimiento que se tiene del objeto de estudio. Palabras clave: estadísticas culturales, indicadores culturales, planificación cultural. Quantitative and qualitative research: studies of cultural uses and motivations for roundtrip cantes Abstract: This paper provides a link and continuity to research activities related to several behavioural aspects of university cultural consumption that have been carried out by the Cultural Observatory of the Atalaya Project. Specifically, the studies under review are those grouped under the generic denomination of Proyecto USOS, as well as the study entitled A Qualitative Study of the Cultural Motivations of University Students, which is currently underway. Given the inherent complexity of cultural consumption behaviour and the different facets that may be involved in it, the paper argues in favour of using quantitative and qualitative methodologies as springboards that enable the knowledge gleaned from the object of study to be enriched. Keywords: cultural statistics, cultural indicators, cultural planning.  Artículo recibido: 22/09/2009. Aceptado: 30/09/200

Fibrous Hamartoma of Infancy: A Series of 21 Cases and Review of the Literature

Introducción: El hamartoma fibroso de la infancia (HFI) es tumor poco frecuente de tejidos blandos en lactantes y niños, caracterizado histopatólogicamente por su morfología trifásica y curso benigno. Métodos: Presentamos las características histopatológicas e inmunohistoquímicas de una serie de 21 casos de HFI y revisamos sus principales diagnósticos diferenciales. Resultados: Las lesiones predominaron en varones con una edad media de 3,7 años (5 meses24 años) en localizaciones previamente descritas. Histopatológicamente, se caracterizaron por proporciones variables de tejido fibroblástico, mesenquimal y adiposo maduro. Tres casos (21%) mostraron zonas hialinizadas con artefactos en grietas, que imitaban al fibroblastoma de células gigantes. Presentaron tinción positiva para actina de músculo liso 8/13 (61%) en el componente fibroblástico, CD34 en 6/8 (75%) en el mesenquimal inmaduro y fibroblástico; y S100 en el tejido adiposo en 7/7 (100%). Conclusión: Nuestros hallazgos histopatológicos son superponibles a los descritos en series amplias. No obstante, la heterogeneidad clínica obliga a conocer las variantes de esta entidad dentro de su típica histomorfología trifásica, para lograr un correcto diagnóstico y manejo terapéutico.Background: Fibrous hamartoma of infancy (FHI) is a rare soft-tissue tumor usually seen in infants and young children. Histologically, the tumor is characterized by a triphasic morphology, and the clinical course is benign. Methods: We described the histopathologic and immunohistochemical features in a series of 21 cases of FHI and reviewed the main entities to consider in differential diagnosis. Results: Most patients in the series were male. The mean age was 3.7 years (range, 5 months---24 years), and lesions were found in locations that have been previously reported. Histopathologically, the tumors were composed of variable proportions of fibroblastic, mesenchymal, and mature adipose tissue. Three of the 13 immunohistochemically stained biopsies (14%) contained hyalinized zones with cracking artifacts, mimicking giant cell fibroblastoma. Eight of the 13 stained with smooth-muscle actin (61%) were positive in the fibroblastic component, 6 of the 8 stained with CD34 (75%) were positive in the immature mesenchymal and fibroblastic components, and all 7 stained with S100 were positive (100%) in adipose tissue. Conclusions: Our histopathologic findings are consistent with those described in larger series. However, in order to reach a precise diagnosis and plan treatment, clinical heterogeneity obliges us to become familiar with variations in the characteristic triphasic histology of FHI