98 research outputs found

    Habitacions = Habitations

    Get PDF

    A revised Ordovician age for the Sisargas orthogneiss, Galicia (Spain). Zircon U-Pb ion-microprobe and LA-ICPMS dating

    Get PDF
    The Sisargas orthogneiss is located in the Schistose Domain of the Galicia Trás-Os-Montes Zone. It has previously been dated by Allegret and Iglesias (1987) who reported an U-Pb upper intercept at 570 ± 14 Ma, considered to be the crystallization age. For this reason, the Sisargas orthogneiss has traditionally been considered one of the oldest magmatic rocks of the Central Iberian Zone. However, new SIMS and LA-ICPMS data reveal that it crystallized at 479 ± 7 Ma and contains zircons with abundant pre-magmatic cores with ages clustering at 585 ± 15 Ma. This suggests that the Sisargas orthogneiss derives from the melting of a Pan-African protolith

    Técnicas geomatemáticas para la separación de diferentes series de rocas ígneas a partir de elementos mayores

    Get PDF
    RESUMEN: En este trabajo se pretende determinar si en un conjunto aleatorio de especímenes de rocas ígneas resulta posible identificar qué series diferentes coexisten y, en tal caso, adscribir cada espécimen a la serie a que pertenece. Para ello se han estudiado cerca de 1.000 especímenes, recogidos de la literatura, pertenecientes a series (1) tholeíticas (2) alcalinas y (3) calcoalcalinas. Se concluye que, para efectuar una separación efectiva entre los distintos tipos de series, es necesario normalizar los especímenes. Se han estudiado dos técnicas de normalización: (1) al 57% de Si02 y (2) al valor cero de las coordenadas sobre la proyección en la primera componente principal. Ambas producen una buena separación, pero la normalización al 57% de Si02 genera un gran número de valores negativos, por lo que el porcentaje de especímenes que deben eliminarse del estudio es mayor que en el caso de utilizar la otra técnica, que por tanto, parece más adecuada

    Osteolisis en artroplastia total de cadera metal-metal de segunda generación. Aportación de un caso

    Get PDF
    Presentamos un caso de un paciente de 63 años, portador de una prótesis total de cadera no cementada metal-metal, que a los quince meses de postoperatorio presentó una fractura periprotésica tras una caída. El paciente presentaba osteolisis y aflojamiento del cotilo y del vástago, con gran cantidad de líquido articular. Se practicaron estudios histológicos de los tejidos periprotésicos y un análisis de las superficies de contacto del cono del vástago. Se observaron pequeños infiltrados de células linfocíticas, y macrófagos de localización perivascular con partículas metálicas en su interior. Los cultivos fueron negativos para infección. Se detectó desgaste en la zona del cono del vástago en contacto con la cabeza, lo que justifica un rozamiento mecánico cabeza-cono. Se trata de una caso de osteolisis de presentación precoz, con movilización de los implantes no cementados, probablemente secundario a un aumento de la presión del líquido intraarticular.A seventy-six-year-old patient was seen at our hostpital, because he suffered a periprosthetic fracture 15 months alter performing a mental-on-mettal uncemmented total hip arthroplasty. He had severe osteolysis and loosening of the total hip components, with a lot of intraarcular fluid. Histological examination of the periprosthetic tissues and biomechanical study of the damage of the materials were done. There were macrophages around the vessels with metal particles inside. All of the intraoperative cultures were negative for infection. This is an early loosening uncemmented total hip arthroplasty due to osteolysis probably secondary to fluid pressure

    Current causes of death in familial hypercholesterolemia

    Get PDF
    Background Familial hypercholesterolemia (FH) is a codominant autosomal disease characterized by high low-density lipoprotein cholesterol (LDLc) and a high risk of premature cardiovascular disease (CVD). The molecular bases have been well defined, and effective lipid lowering is possible. This analysis aimed to study the current major causes of death of genetically defined heterozygous familial hypercholesterolemia (heFH). Methods A case‒control study was designed to analyse life-long mortality in a group of heFH and control families. Data from first-degree family members of cases and controls (nonconsanguineous cohabitants), including deceased relatives, were collected from a questionnaire and review of medical records. Mortality was compared among heFH patients, nonheFH patients, and nonconsanguineous family members. Results A total of 813 family members were analysed, 26.4% of whom were deceased. Among the deceased, the mean age of death was 69.3 years in heFH individuals, 73.5 years in nonheFH individuals, and 73.2 years in nonconsanguineous individuals, without significant differences. CVD was the cause of death in 59.7% of heFH individuals, 37.7% of nonheFH individuals, and 37.4% of nonconsanguineous individuals (P = 0.012). These differences were greater after restricting the analyses to parents. The hazard ratio of dying from CVD was 2.85 times higher (95% CI, (1.73–4.69) in heFH individuals than in individuals in the other two groups (non-FH and nonconsanguineous), who did not differ in their risk. Conclusions CVD mortality in heFH individuals is lower and occurs later than that described in the last century but is still higher than that in non-FH individuals. This improved prognosis of CVD risk is not associated with changes in non-CVD mortality

    Beneficial effects of omega-3 fatty acids in the proteome of high-density lipoprotein proteome

    Get PDF
    BACKGROUND: Omega-3 poly-unsaturated fatty acids (ω-3 PUFAs) have demonstrated to be beneficial in the prevention of cardiovascular disease, however, the mechanisms by which they perform their cardiovascular protection have not been clarified. Intriguingly, some of these protective effects have also been linked to HDL. The hypothesis of this study was that ω-3 PUFAs could modify the protein cargo of HDL particle in a triglyceride non-dependent mode. The objective of the study was to compare the proteome of HDL before and after ω-3 PUFAs supplemented diet. METHODS: A comparative proteomic analysis in 6 smoker subjects HDL before and after a 5 weeks ω-3 PUFAs enriched diet has been performed. RESULTS: Among the altered proteins, clusterin, paraoxonase, and apoAI were found to increase, while fibronectin, α-1-antitrypsin, complement C1r subcomponent and complement factor H decreased after diet supplementation with ω-3 PUFAs. Immunodetection assays confirmed these results. The up-regulated proteins are related to anti-oxidant, anti-inflammatory and anti-atherosclerotic properties of HDL, while the down-regulated proteins are related to regulation of complement activation and acute phase response. CONCLUSIONS: Despite the low number of subjects included in the study, our findings demonstrate that ω-3 PUFAs supplementation modifies lipoprotein containing apoAI (LpAI) proteome and suggest that these protein changes improve the functionality of the particle

    Compositional Evolution of the Variscan Intra-Orogenic Extensional Magmatism in the Valencia del Ventoso Plutonic Complex, Ossa-Morena Zone (SW Iberia): A View from Amphibole Compositional Relationships

    Get PDF
    The Ossa-Morena Zone (OMZ), SW Iberia, has numerous Lower Carboniferous compositionally zoned plutons that formed in a Variscan intra-orogenic extensional setting. This magmatism shows a wide compositional variation comprising alkaline, transitional, and calc-alkaline suites. The calc-alkaline suite was produced by hybridization of alkaline magmas with felsic melts generated by crustal anatexis related to the intrusion of mafic magmas in the middle crust. In this work, we present a textural and mineralogical study of the Variscan Valencia del Ventoso main pluton from the OMZ to track the compositional evolution of magmas during hybridization using constraints from amphibole compositions and to determine the P-T conditions of emplacement using amphibolebased thermobarometry. This pluton exhibits reverse zoning with an inner facies containing alkaline dolerites, gabbros, and quartz diorites, an intermediate facies with transitional diorites, and an outer facies with calc-alkaline quartz diorites to monzogranites. Magmas from the intermediate and border facies crystallized under oxidizing conditions at relatively low temperatures (range: 640–760 ◦C) and ca. 280–300 MPa, implying near H2O-saturated conditions. These rock facies show mineralogical evidence of hybridization between alkaline to mildly alkalic and calc-alkaline magmas. The former is inferred from the occurrence of antecrysts of labradorite-andesine, high-Ti pargasite-hastingsite, and biotite with deficiency in tetrahedral-site occupancy, a distinctive feature of biotite from the inner facies alkaline dolerites. This contrasts with later crystallization from the calc-alkaline magma of andesine-oligoclase, low-Ti magnesiohornblende-edenite, and biotite with full tetrahedral-site occupancy. Constraints from amphibole-melt compositional relationships in antecrystic high-Ti amphibole suggest that the alkaline magmatic component could have a high- to ultra-K affinity.Ministerio de Economía y Competitividad (Gobierno de España), CGL2017-84469-

    New insights from U–Pb zircon dating of Early Ordovician magmatism on

    Get PDF
    The Central Iberian–Ossa-Morena transition zone (SW Iberian Massif) represents a segment of the northern Gondwana margin with a long geodynamic evolution, characterized by the superposition of Cadomian and Variscan events. The Early Ordovician is mainly represented by porphyritic felsic volcaniclastic rocks (the Urra Formation) that pass up into a siliciclastic sediments typical of the Central Iberian Zone (Lower Ordovician Armorican Quartzite Formation). The Urra Formation unconformably overlies the previously deformed and metamorphosed Ediacaran sediments of the Série Negra (with Ossa-Morena Zone paleogeographic affinity). New SHRIMP zircon data obtained from the Urra Formation volcaniclastic rocks indicate an Early Ordovician age (206Pb/238U ages ranging from 494.6±6.8 Ma to 488.3±5.2 Ma) for this magmatic event. The inherited zircon cores indicate the presence of multicycle protoliths with different Precambrian ages: Neoproterozoic (698–577 Ma), Paleoproterozoic (2.33 Ga) and Paleoarchean (3.2–3.3 Ga). There is a noticeable lack of Meso- to Neoarchean and Mesoproterozoic ages. The data support the hypothesis that the volcaniclastic rocks were derived by partial melting of Cadomian basement (linked to a West African Craton provenance). The Urra Formation volcaniclastic rocks have rhyolitic to dacitic compositions, are peraluminous and similar to calc-alkaline high-K series suites elsewhere. Isotopic signatures present a wide range of values (87Sr/86Sr)t=0.7085–0.7190, more restricted εNdt (−2.65 to −0.35) and δ18O=9.63–10.34‰, compatible with magmas derived from crustal rocks, including portions of the lower crust. Some samples show disturbance of the Rb–Sr system as shown by unrealistic values for (87Sr/86Sr)tb0.703, probably due to Variscan deformation and metamorphism. The volcaniclastic rocks with a significant sedimentary contribution (upper unit) are distinguished from the others by the lowest values of εNdt (−5.53 to −4.85). The geochemical data are compatible with an orogenic geodynamic environment. However, the “orogenic” signature can be considered to represent, in part, an inherited feature caused by melting of the Cadomian basement which also has calc-alkaline affinities. The Early Ordovician crustal growth and associated magmatism, represented by the Urra felsic volcaniclastic rocks and associated calc-alkaline granitoids, diorites and gabbros, can be interpreted in terms of the underplating and temporal storage of mantle-derived magmas as the potential source for the “orogenic melts” that were intruded during Early Paleozoic extension. This record of Early Ordovician magmatism has striking similarities with other correlatives from the Iberian, Bohemian and Armorican massifs that are discussed in this paper. This comparison reinforces the probable existence of a large-scale crustal melting process linked to a significant episode of extension on the northern Gondwana margin that probably resulted in the birth of the Rheic Ocean

    Model of mantle-crust interaction and magma generation in the suprasubduction orogen (Paleozoic of the Urals)

    Get PDF
    A model of magma formation in the crust of the Urals mobile belt, which is the best example of epioceanic suprasubduction orogen, has been developed. Magma formation occurs both in the relic oceanic and in the newly formed orogen crust. In the first case small bodies of practically non-potassium plagiogranites are formed, in the second one can see large gabbro-tonalite-granodiorite-granite (GTGG) and essentially granite massifs. The main conclusion is that the formation of a new earth crust of the Urals mobile belt and magma generation in it was initiated by the replacement of low-water mantle magmatism with water-rich one. The latter accompanies crustal magma generation at all its stages. In the areas of intense water magmatism, centers of long-term (up to 100 million years or more) endogenous activity (CLEA) are formed, the products of which are GTGG and granite massifs. Two main stages are distinguished in the evolution of the CLEA: 1) spontaneous partial melting (automigmatization) of products of water-rich basic magmatism - hornblende gabbros and diorites, and formation of tonalite, granodiorite and plagiogranite melts; 2) partial melting of the tonalite and granodiorite which produces the melts of adamellitic and granite composition

    The Quaternary Kurobegawa Granite: an example of a deeply dissected resurgent pluton

    Get PDF
    H.I thank M. Yukawa for her help with sample preparation and LA-ICP-MS data collection, and Y. Hirata for sampling. U-Pb ages were calculated using an Excel spreadsheet provided by S. Sakata. English was improved by M. Coble. Comments by O. Bachmann, J. Wotzlaw and an anonymous reviewer were helpful to improve the manuscript. The Kansai Electric Power Co., Inc., and the Japan Ministry of the Environment gave us permission for the sampling. This work was partly supported by JSPS KAKENHI Grant Number JP16K05617. AC acknowledges the research grant "Beca Puente" and the financial support of a "Plan Propio" grant from the University of Granada Vicerrectorate of Research and Transfer. This is the IBERSIMS publication n. 88.The Quaternary Kurobegawa Granite, central Japan, is not only the youngest known granitic pluton exposed on the Earth’s surface, it is one of few localities where both Quaternary volcanics and related plutons are well exposed. Here, we present new zircon U–Pb ages together with whole rock and mineral geochemical data, revealing that the Kurobegawa Granite is a resurgent pluton that was emplaced following the caldera-forming eruption of the Jiigatake Volcanics at 1.55 ± 0.09 Ma. Following the eruption, the remnant magma chamber progressively cooled forming the voluminous Kurobegawa pluton in the upper crust (~ 6 km depth) until ~ 0.7 Ma when resurgence caused rapid uplift and erosion in the region. This is the first study to document the detailed spatiotemporal evolution of resurgent pluton for a Quaternary caldera system. Our new findings may contribute significantly to understanding the fate of active caldera systems that can produce supereruptions.Ministry of Education, Culture, Sports, Science and Technology, Japan (MEXT) Japan Society for the Promotion of Science Grants-in-Aid for Scientific Research (KAKENHI) JP16K05617University of Granada Vicerrectorate of Research and Transfe
    corecore