228 research outputs found

    ESTUDIO COMPARATIVO DE LA TRANSFORMACIÓN MINERALÓGICADE ARCILLAS COCIDAS DEL VALLE DE LABOYOS, CUENCA ALTA DELMAGDALENA (COLOMBIA)

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      Las transformaciones mineralógicas durante el quemado de las arcillas del Valle de Laboyos en la Cuenca del Alto Magdalena (Colombia) fueron estudiadas. La cocción de las arcillas se llevó a cabo en el rango de temperatura 800-1200 ºC bajo condiciones oxidantes. Las transformaciones mineralógicas fueron investigadaspor difracción de rayos X (DRX) y microscopía electrónica de barrido (MEB). Importantes diferencias composicionales en las fases neoformadas se observaron en las arcillas. Paragénesis típicas con cuarzo, illita,caolinita, mica, feldespato potásico halloysita y plagioclasa fueron observadas. Varias fases minerales fueron identificadas en las arcillas quemadas, con productos de reacción incluyendo mullita, cuarzo residual, hematita,fase amorfa (vidrio generado por la fusion de feldespatos y arcillas) en las arcillas cocidas. Palabras clave: Transformaciones mineralógicas, Arcillas, Valle de Laboyos, Fases neoformadas, Paragénesis.Mineralogical transformations during firing of clays from the Laboyos Valley at the Upper Magdalena Basin(Colombia) were studied. Firing of clays was carried out in the temperature range 800–1200 °C under oxidizing conditions. The mineralogical transformations were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Important compositional differences in the neoformed phases were observed inthe clays. Typical assemblages with quartz, illite, kaolinite, mica, halloysite, potassium feldspar and plagioclase were observed. Several mineral phases were identified in the fired clays, with the reaction products including mullite, residual quartz, hematite, amorphous phase (glass generated by melting of feldspars and clays) in thefired clays. Keywords: Mineralogical transformations, Clays, Laboyos Valley, Neoformed phases, Assemblages. &nbsp

    ESTUDIO COMPARATIVO DE LA TRANSFORMACIÓN MINERALÓGICADE ARCILLAS COCIDAS DEL VALLE DE LABOYOS, CUENCA ALTA DELMAGDALENA (COLOMBIA)

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      Las transformaciones mineralógicas durante el quemado de las arcillas del Valle de Laboyos en la Cuenca del Alto Magdalena (Colombia) fueron estudiadas. La cocción de las arcillas se llevó a cabo en el rango de temperatura 800-1200 ºC bajo condiciones oxidantes. Las transformaciones mineralógicas fueron investigadaspor difracción de rayos X (DRX) y microscopía electrónica de barrido (MEB). Importantes diferencias composicionales en las fases neoformadas se observaron en las arcillas. Paragénesis típicas con cuarzo, illita,caolinita, mica, feldespato potásico halloysita y plagioclasa fueron observadas. Varias fases minerales fueron identificadas en las arcillas quemadas, con productos de reacción incluyendo mullita, cuarzo residual, hematita,fase amorfa (vidrio generado por la fusion de feldespatos y arcillas) en las arcillas cocidas. Palabras clave: Transformaciones mineralógicas, Arcillas, Valle de Laboyos, Fases neoformadas, Paragénesis.Mineralogical transformations during firing of clays from the Laboyos Valley at the Upper Magdalena Basin(Colombia) were studied. Firing of clays was carried out in the temperature range 800–1200 °C under oxidizing conditions. The mineralogical transformations were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Important compositional differences in the neoformed phases were observed inthe clays. Typical assemblages with quartz, illite, kaolinite, mica, halloysite, potassium feldspar and plagioclase were observed. Several mineral phases were identified in the fired clays, with the reaction products including mullite, residual quartz, hematite, amorphous phase (glass generated by melting of feldspars and clays) in thefired clays. Keywords: Mineralogical transformations, Clays, Laboyos Valley, Neoformed phases, Assemblages. &nbsp

    Synaptic, axonal damage and inflammatory cerebrospinal fluid biomarkers in neurodegenerative dementias

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    INTRODUCTION: Synaptic damage, axonal neurodegeneration, and neuroinflammation are common features in Alzheimer's disease (AD), frontotemporal dementia (FTD), and Creutzfeldt-Jakob disease (CJD). METHODS: Unicentric cohort of 353 participants included healthy control (HC) subjects, AD continuum stages, genetic AD and FTD, and FTD and CJD. We measured cerebrospinal fluid neurofilament light (NF-L), neurogranin (Ng), 14-3-3, and YKL-40 proteins. RESULTS: Biomarkers showed differences in HC subjects versus AD, FTD, and CJD. Disease groups differed between them except AD versus FTD for YKL-40. Only NF-L differed between all stages within the AD continuum. AD and FTD symptomatic mutation carriers presented differences with respect to HC subjects. Applying the AT(N) system, 96% subjects were positive for neurodegeneration if 14-3-3 was used, 94% if NF-L was used, 62% if Ng was used, and 53% if YKL-40 was used. DISCUSSION: Biomarkers of synapse and neurodegeneration differentiate HC subjects from neurodegenerative dementias and between AD, FTD, and CJD. NF-L and 14-3-3 performed similar to total tau when AT(N) system was applied

    Petrography and application of the rietveld method to the quantitative analysis of phases of natural clinker generated by coal spontaneous combustion

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    Fine-grained and mainly reddish color, compact and slightly breccious and vesicular pyrometamorphic rocks (natural clinker) are associated to the spontaneous combustion of coal seams of the Cerrejón Formation exploited by Carbones del Cerrejón Limited in La Guajira Peninsula (Caribbean Region of Colombia). These rocks constitute remaining inorganic materials derived from claystones, mudstones and sandstones originally associated with the coal and are essentially a complex mixture of various amorphous and crystalline inorganic constituents. In this paper, a petrographic characterization of natural clinker, aswell as the application of the X-ray diffraction (Rietveld method) by mean of quantitative analysis of its mineral phases were carried out. The RIQAS program was used for the refinement of X ray powder diffraction profiles, analyzing the importance of using the correct isostructural models for each of the existing phases, which were obtained from the Inorganic Crystal Structure Database (ICSD). The results obtained in this investigation show that the Rietveld method can be used as a powerful tool in the quantitative analysis of phases in polycrystalline samples, which has been a traditional problem in geology

    向精神薬服用患者の突然死症例におけるカリウムイオンチャネルに関する分子生物学的解析:QT延長症候群関連遺伝子の多型が危険因子となり得るか?

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    Psychotropic drugs can pose the risk of acquired long QT syndrome (LQTS). Unexpected autopsy-negative sudden death in patients taking psychotropic drugs may be associated with prolonged QT intervals and life-threatening arrhythmias. We analyzed genes that encode for cardiac ion channels and potentially associated with LQTS, examining specifically the potassium channel genes KCNQ1 and KCNH2 in 10 cases of sudden death involving patients administered psychotropic medication in which autopsy findings identified no clear cause of death. We amplified and sequenced all exons of KCNQ1 and KCNH2, identifying G643S, missense polymorphism in KCNQ1, in 6 of the 10 cases. A study analysis indicated that only 11% of 381 healthy Japanese individuals carry this polymorphism. Reports of previous functional analyses indicate that the G643S polymorphism in the KCNQ1 potassium channel protein causes mild IKs channel dysfunction. Our present study suggests that administering psychotropic drug therapy to individuals carrying the G643S polymorphism may heighten the risk of prolonged QT intervals and life-threatening arrhythmias. Thus, screening for the G643S polymorphism before prescribing psychotropic drugs may help reduce the risk of unexpected sudden death2013博士(歯学)松本歯科大

    Revista de Vertebrados de la Estación Biológica de Doñana

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    Página 298 con error de impresiónEstudio cariológico en dos especies de Serránidos del Mediterráneo (Peces: PerciformesRelaciones morfométricas de Atherina boyeri Risso (Pisces: Atherinidae) de la laguna de Zoñar (Córdoba, España)Contribución al conocimiento de la biometríay osteología de Barbus barbus bocagei, Steindachner, 1866 (Pisces: CyprinidaeLa actividad de la salamandra, Salamandra salamandra (L.), en Galicia.Estudios sobre el sapo corredor (Bufo calamita) en el Sur de España.1. BiometríaEstudios sobre el sapo corredor (Bufo calamita) en el Sur de España. II. AlimentaciónBiología de la reproducción de Rana iberica Boulenger 1879 en zonas simpátridas con Rana temporaria Linneo, 1758Nuevos datos sobre la distribución geográfica de Lacerta monticola cantabrica Mertens, 1929. (Sauria, lacertidae).Datos sobre Lacerta monticola Boulenger, 1905 (Saurio: lacertidae)en el oeste del Sistema Central.Nueva especie de Anolis (lacertilia, Iguanidae) para CubaEtograma cuantificado del cortejo en Falco naumannOntogénesis del comportamiento predador en Falco naumanniContaminación xenobiótica del Parque Nacional de Doñana. 1. Residuos de insecticidas organoclorados, bifenilos policlorados y mercurio en anseriformes y gruiformesReproducción del críalo (Clamator glandarius) en Sierra Morena CentraNidificación de Picus viridis en taludes de arcilla en Ramblas de Guadix (Granada)Comportamiento del calamón Porphyrio porphyrio (Linnaeus, 1758) en Doñana, Marismas del GuadalquiviBiología y ecología de la malvasía (Oxyura leucocephala) en Andalucía.On the differential diet of Carnivora in islands:a method for analysing it and a particular case.Notas sobre la distribución pasada y actual del meloncillo Herpestes ichneumon (L.) en la Península IbéricaEstructuración de las interacciones en una camada de lobos (Canís lupus)Nuevos datos sobre la distribución del Cottus gobio L. (pisces, cottidae) en EspañaSobre la alimentación de Callopistes maculatus (Reptilia,teiidaeObservación de Lacerta lepida depredando un nido de Alectoris rufaNueva cita del galápago leproso Mauremys leprosa (Scheigger, 1812) en los pirineosPrimera cita de Psammodromus hispanicus (Fitzinger) para GaliciaSobre la presencia de Gallotia (=Lacerta) atlantica (Peters y Doria, 1882) en Gran CanariaNota sobre las Lacerta monticola Boulenger, 1905 de las zonas del norte de GaliciaPrimeras notas herpetológicas de la provincia de Soria.Datos sobre selección de hábitat y ecología alimenticia del porrón pardo (Aythya nyroca)Probable nueva área de cría del pechiazul (Luscinia svecica cyanecula) en el sistema central. PerisPredación de Falco peregrinus y Falco subbuteo sobre quirópterosResultados de la producción de Oxyura leucocephala en el año 1981 en las lagunas de Zóñar y el rincónAnálisis de la dieta de Tyto alba en un medio árido antropógeno de los alrededores de Almería¿Son Eudocimus ruber y E. albus distintas especies?EL Estornino pinto (Sturnus vulgaris) en Canarias: nueva especie nidifiante en el archipiélagoDatos sobre la alimentación otoñal del cárabo (Strix aluco) en la sierra de CádizObservación primaveral de rapaces y otras aves en el páramo del estado de Mérida (Venezuela).Murciélago hematófago (Desmodus rotundus) parasitando a un chigüire (Hidrochoerus hydrochaeris)Observaciones sobre la reproducción del zacatuche o teporinho Romerolagus diazi (Mammalia: lagomorpha)Estudio electroforético de hemoglobinas y esterasas sanguíneas en Rhinolophus ferrumequinum (Chiroptera: rhinolophidae) y de hemoglobinas en Tadaria taeniotis (chiroptera: molossidae)Peer reviewe

    Database of spatial distribution of non indigenous species in Spanish marine waters

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    Research in marine Spanish waters are focused on several actions to achieve an effectively management on protected areas, with the active participation of the stakeholders and research as basic tools for decision-making. Among these actions, there is one about the knowledge and control on NIS. One of its objectives is the creation of NIS factsheets, which are going to be added to the National Marine Biodiversity Geographical System (GIS) providing complementary information about taxonomic classification, common names, taxonomic synonyms, species illustrations, identification morphological characters, habitat in the native and introduced regions, biological and ecological traits, GenBank DNA sequences, world distribution, first record and evolution in the introduced areas, likely pathways of introduction, effects in the habitats and interaction with native species, and potential management measures to apply. The database will also provide data for (1) the European online platforms, (2) the environmental assessment for the Descriptor 2 (D2-NIS) of the EU Marine Strategy Framework Directive (MSFD), as well as (3) supporting decisions made by stakeholders. It is the result of extensive collaboration among scientist, manager’s and citizen science in the Spanish North-Atlantic, South-Atlantic, Gibraltar Strait-Alboran, Levantine-Balearic and Canary Islands marine divisions, providing an updated overview of the spatial distribution of relevant extended and invasive NIS of recent and established NIS introduced by maritime transport and aquaculture pathways, as well as on cryptogenic or native species in expansion due to the climatic water warming trend
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