Southward migration of magmatic activity in the Colima volcanic complex, Mexico: an ongoing process

"The Colima Volcanic Complex trends in a nearly N-S direction in western Mexico, and one of its structures, Colima volcano, is the most historically active volcano in the country. Immediately to the N, there is another volcanic center called El Cántaro volcano, whose activity started around 1.7 Ma in its N portion and migrated to the S in various episodes. Volcanic activity migrated further south, from El Cántaro to the Colima Volcanic Complex where the southernmost manifestation, Hijos del Volcán domes, is located on the south slope of Fuego volcano. The above date appears to mark initiation of the rather continuous volcanic activity in the area. It has been noted that these volcanic manifestations lie on, or near the Rivera-Cocos inland plate boundary. Colima’s Fuego volcano is also the closest to the Middle America Trench, among the polygenetic volcanoes in Mexico. We submit that the anomalous location of volcanism in this area originates in an anomalous subduction process of the Rivera and Cocos plates and evoke a tectonic model, proposed elsewhere, to support the idea. Modeling gravimetric and aeromagnetic data we locate the magma chambers of the Fuego (active) and Nevado (extinct) volcanoes within a 65 mGals negative Bouguer anomaly elongated in a nearly N-S direction. The corresponding aeromagnetic map displays a magnetic high over the southern portion of the Fuego volcano edifice. We found two additional, associated structures whose anomalies have not been previously reported, which appear to follow the southward magmatic migration pattern. One of them is a collapse structure with a circular topographic expression, and the southernmost is a low-density intrusion ~1 km below sea level, associated with a moderate topographic bulge at the surface that we interpret as a magma body. Five lines cross the anomalies; gravimetric and magnetic fields are concurrently modeled along them to locate the magmatic bodies. In addition to the 2-D models we perform 3-D gravimetric and magnetic inversions. For each field a 3-D mesh is built under the area occupied by the Colima Volcanic Complex, the volume elements are then assigned density or magnetic susceptibility values and their surface contributions in various points are evaluated. The process is iterated until the difference between the measured and the calculated fields is less than a predetermined value. The results of each inversion adequately and independently define the location of the magmatic cham- bers

Radiometric Mapping of Hydrothermal Alterations in Isla Isabel, Mexico

Isla Isabel is a small island of volcanic origin about 29 km west of Nayarit’s coast, Mexico, exhibiting phreatomagmatic activity (maars). In a nearby (8 km), ocean located, exploration well reaching 3157 m geothermal gradients of 73°C/km were recorded, which are among the largest in the world. These features, plus gravimetric anomalies in the area, suggest that the region may become an important source of geothermal energy. Direct hydrothermal alteration mapping in the island is difficult since it is a National Park and a bird sanctuary where various bird species thrive. We used remote sensing techniques to identify hydrothermally altered sections in the island, including radiometric spectrum determinations in the 350–1050 nm wavelength interval and Landsat 8 satellite imagery. The island is mainly composed of basalt but large portions contain vegetation, posing a challenge to satellite hydrothermal alteration detection. Four pixel-classification schemes are used for oxides, hydroxyls, and vegetation; shallow underwater basalt flow detection was possible

Ecosystem Services Linked to Water and Plant Diversity in the Igualata Paramo of Hualcanga Region

The present investigation proposes to study the ecosystem services linked to water and floristic diversity in the Igualata paramo of the Hualcanga region; 5 sampling plots of 25 m2 were installed, with 4 subplots of 1 m2. 30 samples of terrestrial vascular plants were obtained, identifying 17 botanical families, 26 genera, and 27 species, and 1 lichen and 1 moss of unidentified family and genus. It was determined that the species that stands out with the highest importance value index was Lachemilia orgiculata with 44.06%, because the species was found in 4 of the 5 study plots. In second place we have Calamagrostis intermedia species with 8.21%, while the species Vicea sp. was the species with the lowest importance value index of 0.50%, being the species with the lowest number of individuals. The Rosaceae family presented the highest index with 39.61%. The Poaceae and Asteraceae families also present dominance in this ecosystem with values of 9.63% and 5.79%, respectively. According to the Shannon index, plots P2 and P4 were those with high diversity, which corroborates with what was obtained in the Simpson index; the Sorensen index showed us that plots P4 and P5 are very similar, plots P1 and P3 are fairly similar, and the remaining plots are dissimilar, which indicated that vegetation can be found in certain areas of the investigation. The water flow supplying the resident families of the region was found to be 8.12 L/s, and its ecological flow is of 0.83 L/s, having a flow that satisfies the needs of the inhabitants. Keywords: caudal, ecological flow, ecosystem paramo, ecosystem services, floristic diverity, indices of diversity. Resumen La presente investigación propone: estudiar los servicios ecosistémicos ligados al agua y diversidad florística en el páramo del Igualata regional Hualcanga; se instalaron cinco parcelas de muestreo de 25 m2 con 4 sub parcelas de 1 m2, se obtuvo 30 muestras de plantas vasculares terrestres, identificando 17 familias botánicas, 26 géneros y 27 especies, además se colectó 1 liquen y 1 musgo de familia, género y especie no identificado. Se determinó que la especie que sobresale con mayor índice de valor de importancia fue Lachemilia orgiculata con un 44,06%, esto se debe a que la especie se encontraba en 4 de las 5 parcelas de estudio, en segundo lugar, tenemos a Calamagrostis intermedia especie con 8,21%, mientras que la especie Vicea sp. fue la que menor índice de valor de importancia presentó con un 0,50% esto se debe a que fue la especie con menor cantidad de individuos. La familia Rosaceae presentó el mayor índice con 39,61%, las familias Poaceae, y Asteraceae presentan una dominancia en este ecosistema con valores de 9,63% 5,79%, respectivamente. De acuerdo al índice de Shannon las parcelas 2 y 4 son las que poseen diversidad alta que se corrobora con lo obtenido en el índice de Simpson; en el índice de Sorensen nos muestra que las parcelas P4 vs P5 son muy similares las parcelas P1 y P3 son medianamente similares y las parcelas restantes son disimiles lo que indica que la vegetación se puede encontrar en ciertas zonas de la investigación. El caudal que posee la Regional es de 8,12 L/s, abasteciendo a las familias y su caudal ecológico es de 0,83 L/s teniendo un caudal que satisface las necesidades de los pobladores. Palabras clave: caudal, caudal ecológico, diversidad florística, ecosistema páramo, índices de diversidad, servicios ecosistémicos.&nbsp

Psychometric properties of the healthy lifestyle questionnaire for ecuadorian university students (EVS-EUE)

University students are considered a key population in promoting and establishing healthy lifestyles that will ensure a full life for the next generations. The purpose of this study was to do a cultural and linguistic adaptation of the healthy lifestyle questionnaire for Ecuadorian university students (EVS-EUE). Two thousand, one hundred and eight (2108) students from 17 to 19 years old (27%), 20 to 24 years old (57%), and over 24 years old (16%) participated (M = 21.81 years; SD = 3.04). A confirmatory factor analysis, internal consistency analysis, and concurrent validity were conducted. The results of the EVS-EUE Questionnaire presented adequate values (x2/d.f = 9.02, Comparative Fit Index (CFI) = 0.96, Incremental Fit Index (IFI) = 0.96, McDonald Fit Index (MFI) = 0.91, Adjusted Goodness of Fit Index (AGFI) = 0.94, Root Mean Square Error of Approximation (RMSEA) = 0.06, Standardized Root Mean Square Residual (SRMR) = 0.03). The internal consistency showed values above 0.70, and analyzed its concurrent validity, reaching adequate values. This study has provided a valid and reliable questionnaire to evaluate healthy lifestyles in the Ecuadorian population.This study was carried out thanks to the contribution of the Ministry of Economy and Infrastructure of the Council of Extremadura, through the European Regional Development Fund—A way to make Europe. (GR18129)

Descripción epidemiológica de un brote de Leptospirosis en el Departamento de Río San Juan, Nicaragua. Mayo - Julio 1999.

Describe epidemiológicamente el brote de leptospirosis ocurrido en el SILAIS de Río San Juan, así como las medidas de control desarrolladas por el MINSA para contenerlo. Estudio de tipo descriptivo transversal

Dynamical origin of the ⋆θ\star_\theta-noncommutativity in field theory from quantum mechanics

We show that introducing an extended Heisenberg algebra in the context of the Weyl-Wigner-Groenewold-Moyal formalism leads to a deformed product of the classical dynamical variables that is inherited to the level of quantum field theory, and that allows us to relate the operator space noncommutativity in quantum mechanics to the quantum group inspired algebra deformation noncommutativity in field theory.Comment: 17 pages, to be published in Phys. Lett.

Cleaning and retreatment protocol for a debonded ceramic restoration

Objectives: The aim of this article is to propose a resin cement cleaning protocol for use before recementing a debonded restoration. Study Design: Ceramic samples were fabricated from IPS d.sign® and IPS e.max Press® and were treated with hydrofluoric acid etching (HF), or HF+silane (S), or HF+S+adhesive or HF+S+A+resin cement. All samples were placed in a furnace at 650º for one minute in order to attempt to pyrolyze the composite. Each step was examined under scanning electron microscopy (SEM). Results: When the cleaning protocol had been performed, it left a clean and retentive surface. Conclusions: If the restoration is placed in a furnace at 650º for one minute, the composite cement will burn or pyrolyze and disappear, allowing conventional retreatment of the ceramic before rebonding