Metasomatism and magmatic assimilation at a gabbro-limestone contact, Christmas Mountains, Big Bend region, Texas

A composite stock of alkaline gabbro and syenite is intrusive into limestone of the Del Carmen, Sue Peake and Santa Elena Formations at the northwest end of the Christmas Mountains. There is abundant evidence of solution of wallrock by magma but nowhere are gabbro and limestone in direct contact. The sequence of lithologies developed across the intrusive contact and across xenoliths is gabbro, pyroxenite, calc-silicate skarn, marble. Pyroxenite is made up of euhedral crystals of titanaugite and sphene in a leucocratic matrix of nepheline, Wollastonite and alkali feldspar. The uneven modal distribution of phases in pyroxenite and the occurrence' of nepheline syenite dikes, intrusive into pyroxenite and skarn, suggest that pyroxenite represents an accumulation of clinopyroxene "cemented" together by late-solidifying residual magma of nepheline syenite composition. Assimilation of limestone by gabbroic magma involves reactions between calcite and magma and/or crystals in equilibrium with magma and crystallization of phases in which the magma is saturated, to supply energy for the solution reaction. Gabbroic magma was saturated with plagioclase and clinopyroxene at the time of emplacement. The textural and mineralogic features of pyroxenite can be produced by the reaction 2( 1-X) CALCITE + AN_XAB_l-X = (1-X) NEPHELINE+ 2(1-X) WOLLASTONITE+ X ANORTHITE+ 2(1-X) CO₂. Plagioclase in pyroxenite has corroded margins and is rimmed by nepheline, suggestive of resorption by magma. Anorthite and wollastonite enter solid solution in titanaugite. For each mole of calcite dissolved, approximately one mole of clinopyroxene was crystallized. Thus the amount of limestone that may be assimilated is limited by the concentration of potential clinopyroxene in the magma. Wollastonite appears as a phase when magma has been depleted in iron and magnesium by crystallization of titanaugite. The predominance of mafic and ultramafic compositions among contaminated rocks and their restriction to a narrow zone along the intrusive contact provides little evidence for the generation of a significant volume of desilicated magma as a result of limestone assimilation.

Within 60 m of the intrusive contact with the gabbro, nodular chert in the Santa Elena Limestone reacted with the enveloping marble to form spherical nodules of high-temperature calc-silicate minerals. The phases wollastonite, rankinite, spurrite, tilleyite and calcite, form a series of sharply-bounded, concentric monomineralic and two-phase shells which record a step-wise decrease in silica content from the core of a nodule to its rim. Mineral zones in the nodules vary 'with distance from the gabbro as follows:

0-5 m CALCITE + SPURRITE + RANKINITE + WOLLASTONITE
5-16 m CALCITE + TILLEYITE ± SPURRITE + RANKINITE + WOLLASTONITE
16-31 m CALCITE + TILLEYITE + WOLLASTONITE
31-60 m CALCITE + WOLLASTONITE
60-plus CALCITE + QUARTZ

The mineral of a one-phase zone is compatible with the phases bounding it on either side but these phases are incompatible in the same volume of P-T-X_CO2.

Growth of a monomineralio zone is initiated by reaction between minerals of adjacent one-phase zones which become unstable with rising temperature to form a thin layer of a new single phase that separates the reactants and is compatible with both of them. Because the mineral of the new zone is in equilibrium with the phases at both of its contacts, gradients in the chemical potentials of the exchangeable components are established across it. Although zone boundaries mark discontinuities in the gradients of bulk composition, two-phase equilibria at the contacts demonstrate that the chemical potentials are continuous. Hence, Ca, Si and CO₂ were redistributed in the growing nodule by diffusion. A monomineralic zone grows at the expense of an adjacent zone by reaction between diffusing components and the mineral of the adjacent zone. Equilibria between two phases at zone boundaries buffers the chemical potentials of the diffusing species. Thus, within a monomineralic zone, the chemical potentials of the diffusing components are controlled external to the local assemblage by the two-phase equilibria at the zone boundaries.

Mineralogically zoned calc-silicate skarn occurs as a narrow band that separates pyroxenite and marble along the intrusive contact and forms a rim on marble xenoliths in gabbro. Skarn consists of melilite or idocrase pseudomorphs of melili te, one or two . stoichiometric calcsilicate phases and accessory Ti-Zr garnet, perovskite and magnetite. The sequence of mineral zones from pyroxenite to marble, defined by a characteristic calc-silicate, is wollastonite, rankinite, spurrite, calcite. Mineral assemblages of adjacent skarn zones are compatible and the set of zones in a skarn band defines a facies type, indicating that the different mineral assemblages represent different bulk compositions recrystallized under identical conditions. The number of phases in each zone is less than the number that might be expected to result from metamorphism of a general bulk composition under conditions of equilibrium, trivariant in P, T and u_CO2. The "special" bulk composition of each zone is controlled by reaction between phases of the zones bounding it on either side. The continuity of the gradients of composition of melilite and garnet solid solutions across the skarn is consistent with the local equilibrium hypothesis and verifies that diffusion was the mechanism of mass transport. The formula proportions of Ti and Zr in garnet from skarn vary antithetically with that of Si Which systematically decreases from pyroxenite to marble. The chemical potential of Si in each skarn zone was controlled by the coexisting stoichiometric calc-silicate phases in the assemblage. Thus the formula proportion of Si in garnet is a direct measure of the chemical potential of Si from point to point in skarn. Reaction between gabbroic magma saturated with plagioclase and clinopyroxene produced nepheline pyroxenite and melilite-wollastonite skarn. The calcsilicate zones result from reaction between calcite and wollastonite to form spurrite and rankinite.

Herpetofaunal Inventories of the National Parks of South Florida and the Caribbean: Volume III. Big Cypress National Preserve

Amphibian declines and extinctions have been documented around the world, often in protected natural areas. Concern for this trend has prompted the U.S. Geological Survey and the National Park Service to document all species of amphibians that occur within U.S. National Parks and to search for any signs that amphibians may be declining. This study, an inventory of amphibian species in Big Cypress National Preserve, was conducted from 2002 to 2003. The goals of the project were to create a georeferenced inventory of amphibian species, use new analytical techniques to estimate proportion of sites occupied by each species, look for any signs of amphibian decline (missing species, disease, die-offs, and so forth.), and to establish a protocol that could be used for future monitoring efforts. Several sampling methods were used to accomplish these goals. Visual encounter surveys and anuran vocalization surveys were conducted in all habitats throughout the park to estimate the proportion of sites or proportion of area occupied (PAO) by each amphibian species in each habitat. Opportunistic collections, as well as limited drift fence data, were used to augment the visual encounter methods for highly aquatic or cryptic species. A total of 545 visits to 104 sites were conducted for standard sampling alone, and 2,358 individual amphibians and 374 reptiles were encountered. Data analysis was conducted in program PRESENCE to provide PAO estimates for each of the anuran species. All of the amphibian species historically found in Big Cypress National Preserve were detected during this project. At least one individual of each of the four salamander species was captured during sampling. Each of the anuran species in the preserve was adequately sampled using standard herpetological sampling methods, and PAO estimates were produced for each species of anuran by habitat. This information serves as an indicator of habitat associations of the species and relative abundance of sites occupied, but it will also be useful as a comparative baseline for future monitoring efforts. In addition to sampling for amphibians, all encounters with reptiles were documented. The sampling methods used for detecting amphibians are also appropriate for many reptile species. These reptile locations are included in this report, but the number of reptile observations was not sufficient to estimate PAO for reptile species. We encountered 35 of the 46 species of reptiles believed to be present in Big Cypress National Preserve during this study, and evidence exists of the presence of four other reptile species in the Preserve. This study found no evidence of amphibian decline in Big Cypress National Preserve. Although no evidence of decline was observed, several threats to amphibians were identified. Introduced species, especially the Cuban treefrog (Osteopilus septentrionalis), are predators and competitors with several native frog species. The recreational use of off-road vehicles has the potential to affect some amphibian populations, and a study on those potential impacts is currently underway. Also, interference by humans with the natural hydrologic cycle of south Florida has the potential to alter the amphibian community. Continued monitoring of the amphibian species in Big Cypress National Preserve is recommended. The methods used in this study were adequate to produce reliable estimates of the proportion of sites occupied by most anuran species, and are a cost-effective means of determining the status of their populations.

La aplicación empresarial del marketing viral y el efecto boca-oreja electrónico. Opiniones de las empresas

[ES] La práctica tradicional del boca-oreja, natural desde hace años como modo de publicidad efectiva sin recurrir a grandes inversiones ni contrataciones en medios masivos se ha convertido en una nueva posibilidad de marketing con la llegada de las nuevas tecnologías e Internet. Así ha aparecido una nueva estrategia de marketing que consiste en explotar las redes sociales preexistentes para producir incrementos exponenciales en conocimiento de marca, denominada marketing viral. El efecto "boca-oreja online" que genera es una herramienta poderosa para las empresas, aunque su verdadero potencial está aún por descubrir. El objetivo del presente trabajo de investigación es analizar este fenómeno a través de una amplia revisión bibliográfica del término, así como un estudio empírico consistente en una entrevista en profundidad realizada a una muestra de importantes empresas españolas. Los resultados indican que el marketing viral puede ser empleado para el beneficio, tanto de grandes empresas con grandes presupuestos, como de pequeños negocios. Las experiencias exitosas de su utilización demuestran que, cuando se usa integrado en el resto de estrategias comerciales de la empresa, puede mejorar la recomendación de la marca e incrementar su notoriedad en el mercado. El marketing viral puede ser ventajoso a la hora de lanzar un nuevo producto al mercado, sin embargo, la efectividad y la medición de las campañas son vistas por muchos académicos y profesionales como un punto débil de la estrategia.

Software como un Servicio: Solución Business Intelligence

El propóosito del proyecto aquíı descrito radica en, por una parte, sentar una base de un sistema de Business Inteligence adaptable a diversos casos de negocio, y por otra, diseñar e implementar una solución completa para una empresa especíıfica fácilmente adaptable a otro caso, incluyendo desde los procesos de Extracción, Transformación y Carga, pasando por el data warehouse hasta el Business Analysis y la Minería de Datos.

Impacto de la web 2.0 en los perfiles profesionales

En pleno siglo XXI, el uso de Internet y los avances no sólo afectan a las personas sino que las empresas también deben evolucionar al mismo ritmo y adaptar todas sus prácticas a dichos avances. Con la aparición de la Web 2.0, ciertos aspectos de las empresas han quedado obsoletos y se han debido adaptar a la nueva era: la era de la comunicación e de la interacción a través de Internet. Se han creado nuevos modelos de negocio, se han mejorado actividades de la cadena de valor, han surgido nuevas estrategias de marketing y comunicación corporativa y se han creado unos nuevos canales de venta, alrededor del fenómeno e-Commerce. En cuanto a los trabajadores, las empresas han comenzado a valorar nuevas competencias relacionadas con el uso de Internet y la Web 2.0. Dichas competencias pueden ser comunes para muchos puestos de trabajo, por ejemplo el uso de redes sociales o la gestión de la información, otras son más específicas y dependen del puesto de trabajo que consideremos. Finalmente, la aparición de la Web 2.0 ha exigido a las empresas a crear nuevas áreas y puestos de trabajo o modificar los actuales para adecuarse a los nuevos tiempos y tendencias. Así surgen los diferentes perfiles profesionales de las áreas de Estrategia Digital, Marketing Digital, Contenido Digital, Social Media, Análisis Big Data, e-Commerce y Mobile Marketing. Estos perfiles gozan de mucha popularidad y demanda por parte de las empresas y se estima que va a crecer aún más el número de puestos relacionados con el ámbito digital, ya que son las profesiones del futuro.

Business plan & innovación: sector restauración

En mi TFG he analizado el sector de la restauración en Vizcaya de cara a establecer las pautas para la implantación de un negocio de hostelería relacionado todo ello con la innovación. ESPAÑOL.

Financial and Economic Report of a Specific Business Group

As a result of the natural evolution of the economy, ever-changing, unpredictable and cyclical, companies must adapt as far as possible to the changes that have taken place in order to continue with their normal operating activities. Likewise, they should also try to maintain a structure for long-term growth, trying at all times to generate the maximum value. The main objective of this project is to provide financial advisory services to a business group, trying to forward solutions and measures that according to the author can be effective. For this end, the situation of the group in question is analysed from early 2008 to the present day, examining its evolution, what steps have been taken together with their corresponding results and the economic-financial situation of the company at the end of last year. Contact with the company was kept throughout the process of analysis and assessment trying to take advantage of the feedback generated so that the appropriate measures can be adopted if the management considers it to be adequate.

A business plan development: the case of a paint company in Douala Camroon by Bomboy & Friends

This paper presents a business plan to create a new company Bomboy & Friends regarding the Exclusive Distribution of a fully Eco Friendly Water-Soluble Anti- Corrosive Prime named Life Guard Active Rust Primer Paint abbreviated as “L.G.A.R.P Paint” in Douala Cameroon and the C.E.M.A.C Region. The lack of quality paint in Cameroon has given the opportunity for a company like Bomboy & Friends to nurture its existence and be part of a fast growing economy, providing a high quality paint competition, very economical, easy to prepare, environmentally friendly, compatible with other brands and accessible to medium and small size companies.