893 resultados para lower Carboniferous


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The Turkish part of the Tethyan realm is represented by a series of terranes juxtaposed through Alpine convergent movements and separated by complex suture zones. Different terranes can be defined and characterized by their dominant geological background. The Pontides domain represents a segment of the former active margin of Eurasia, where back-arc basins opened in the Triassic and separated the Sakarya terrane from neighbouring regions. Sakarya was re-accreted to Laurasia through the Balkanic mid-Cretaceous orogenic event that also affected the Rhodope and Strandja zones. The whole region from the Balkans to the Caucasus was then affected by a reversal of subduction and creation of a Late Cretaceous arc before collision with the Anatolian domain in the Eocene. If the Anatolian terrane underwent an evolution similar to Sakarya during the Late Paleozoic and Early Triassic times, both terranes had a diverging history during and after the Eo-Cimmerian collision. North of Sakarya, the Küre back-arc was closed during the Jurassic, whereas north of the Anatolian domain, the back-arc type oceans did not close before the Late Cretaceous. During the Cretaceous, both domains were affected by ophiolite obduction, but in very different ways: north directed diachronous Middle to Late Cretaceous mélange obduction on the Jurassic Sakarya passive margin; Senonian synchronous southward obduction on the Triassic passive margin of Anatolia. From this, it appears that the Izmir-Ankara suture, currently separating both terranes, is composite, and that the passive margin of Sakarya is not the conjugate margin of Anatolia. To the south, the Cimmerian Taurus domain together with the Beydağları domain (part of the larger Greater Apulian terrane), were detached from north Gondwana in the Permian during the opening of the Neotethys (East-Mediterranean basin). The drifting Cimmerian blocks entered into a soft collision with the Anatolian and related terranes in the Eo-Cimmerian orogenic phase (Late Triassic), thus suturing the Paleotethys. At that time, the Taurus plate developed foreland-type basins, filled with flysch-molasse deposits that locally overstepped the lower plate Taurus terrane and were deposited in the opening Neotethys to the south. These olistostromal deposits are characterized by pelagic Carboniferous and Permian material from the Paleotethys suture zone found in the Mersin mélange. The latter, as well as the Antalya and Mamonia domains are represented by a series of exotic units now found south of the main Taurus range. Part of the Mersin exotic material was clearly derived from the former north Anatolian passive margin (Huğlu-type series) and re-displaced during the Paleogene. This led us to propose a plate tectonic model where the Anatolian ophiolitic front is linked up with the Samail/Baër-Bassit obduction front found along the Arabian margin. The obduction front was indented by the Anatolian promontory whose eastern end was partially subducted. Continued slab roll-back of the Neotethys allowed Anatolian exotics to continue their course southwestward until their emplacement along the Taurus southern margin (Mersin) and up to the Beydağları promontory (Antaya-Mamonia) in the latest Cretaceous-Paleocene. The supra-subduction ocean opening at the back of the obduction front (Troodos-type Ocean) was finally closed by Eocene north-south shortening between Africa and Eurasia. This brought close to each other Cretaceous ophiolites derived from the north of Anatolia and those obducted on the Arabian promontory. The latter were sealed by a Maastrichtian platform, and locally never affected by Alpine tectonism, whereas those located on the eastern Anatolian plate are strongly deformed and metamorphosed, and affected by Eocene arc magmatism. These observations help to reconstruct the larger frame of the central Tethyan realm geodynamic evolution.

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The end-Permian mass extinction greatly affected the sedimentary record, but the sedimentary response was not limited to the Permian-Triassic boundary interval. This transformation extended to sedimentation that spanned the entire Early Triassic. Calcimicrobialites play an important role throughout this time interval, and at least four main events of anomalous carbonate deposition can be shown. A post-extinction calcimicrobial unit occurs above the extensive Permian skeletal carbonate platform exposed in the Taurus Mountains (southern Turkey), in south Armenia, north-west north and Central Iran along the Zagros Mountains. The calcimicrobial unit formed during the flooding of the platform that took place during the earliest Triassic. A similar calcimicrobialite formed during late Griesbachian to Dienerian time atop the shallow Permian skeletal carbonate platform largely exposed in south China. A third event occurred during the Early Olenekian on the first Mesozoic isolated pelagic plateau (Baid seamount, Oman Mountains). Here the change in carbonate sedimentation is reflected in the occurrence of thrombolites and carbonate seafloor fans. Near the end of Early Triassic time, unusual carbonate deposition is recorded both on an isolated pelagic plateau of the Western Tethys (Halstatt limestone of Dobrogea, Romania) and on the eastern Panthalassa margin of the western United States. In the western United States, the event is represented by stromatolites and thrombolites in the Virgin Limestone of the Moenkopi Formation and by seafloor fans in the middle and upper members of the Union Wash Formation. These unusual episodes of anomalous carbonate deposition illustrate a fundamental change in sedimentation that occurred in the aftermath of the end-Permian mass extinction.

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New stratigraphic data along a profile from the Helvetic Gotthard massif to the remnants of the North Penninic basin in eastern Ticino and Graubunden are presented. The stratigraphic record together with existing geochemical and structural data, motivate a new interpretation of the fossil European distal margin. We introduce a new group of Triassic facies, the North-Penninic-Triassic (NPT), which is characterised by the Ladinian ``dolomie bicolori''. The NPT was located in-between the Brianconnais carbonate platform and the Helvetic lands. The observed horizontal transition, coupled with the stratigraphic superposition of a Helvetic Liassic on a Briaconnais Triassic in the Luzzone-Terri nappe, links, prior to Jurassic rifting, the Brianconnais paleogeographic domain at the Helvetic margin, south of the Gotthard. Our observations suggest that the Jurassic rifting separated the Brianconnais domain from the Helvetic margin by complex and protracted extension. The syn-rift stratigraphic record in the Adula nappe and surroundings suggests the presence of a diffuse rising area with only moderately subsiding basins above a thinned continental and proto-oceanic crust. Strong subsidence occurred in a second phase following protracted extension and the resulting delamination of the rising area. The stratigraphic coherency in the Adula's Mesozoic questions the idea of a lithospheric m lange in the eclogitic Adula nappe, which is more likely to be a coherent alpine tectonic unit. The structural and stratigraphic observations in the Piz Terri-Lunschania zone suggest the activity of syn-rift detachments. During the alpine collision these faults are reactivated (and inverted) and played a major role in allowing the Adula subduction, the ``Penninic Thrust'' above it and in creating the structural complexity of the Central Alps. (C) 2012 Elsevier B.V. All rights reserved.

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OBJECTIVE: To assess the association between socio-demographic factors and the quality of preventive care and chronic care of cardiovascular (CV) risk factors in a country with universal health care coverage. METHODS: Our retrospective cohort assessed a random sample of 966 patients aged 50-80years followed over 2years (2005-2006) in 4 Swiss university primary care settings (Basel/Geneva/Lausanne/Zürich). We used RAND's Quality Assessment Tools indicators and examined recommended preventive care among different socio-demographic subgroups. RESULTS: Overall patients received 69.6% of recommended preventive care. Preventive care indicators were more likely to be met among men (72.8% vs. 65.4%; p<0.001), younger patients (from 71.0% at 50-59years to 66.7% at 70-80years, p for trend=0.03) and Swiss patients (71.1% vs. 62.7% in forced migrants; p=0.001). This latter difference remained in multivariate analysis adjusted for gender, age, civil status and occupation (OR 0.68; 95% CI 0.54-0.86). Forced migrants had lower scores for physical examination and breast and colon cancer screening (all p≤0.02). No major differences were seen for chronic care of CV risk factors. CONCLUSION: Despite universal healthcare coverage, forced migrants receive less preventive care than Swiss patients in university primary care settings. Greater attention should be paid to forced migrants for preventive care.

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Lower Coldwater and Palmer Creeks in Butler and Floyd counties are subwatersheds of the Cedar River, which provides drinking water to Cedar Rapids, IA. The increasing concentration of nitrate+nitrate in the river is of concern to the Cedar Rapids water utility, and IDNR snapshot monitoring shows Coldwater and Palmer to be significant potential sources (above the 90th percentile for subwatersheds monitored). Both creeks are also on the Iowa Section 303(d) list of impaired waters (aquatic life). Citizens of these predominantly agricultural watersheds organized the Coldwater-Palmer Watershed Improvement Association to deal proactively with nonpoint source pollutants from crop and livestock operations through a performance-based environmental management program. The locally-adapted program implemented by the Coldwater-Palmer watershed council rewards participants for environmental accomplishments - soil quality improvement and nutrient source reduction as measured by accepted, scientifically-based tests and models. Most of the locally­appropriate BMPs used to improve performance are undertaken voluntarily at participants' initiative. WIRB funds will be combined with funding from the Iowa Com Growers Association and significant in-kind support from the Cedar River Watershed Monitoring Coalition, Iowa State University Extension and other partners. The project will result in sustainable reduction in nutrient loading achieved with voluntary participation of a majority of watershed farm operators.

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Hypertension is a major public health problem and a leading cause of death and disability in both developed and developing countries, affecting onequarter of the world"s adult population. Our aim was to evaluate whether the consumption of gazpacho, a Mediterranean vegetable-based cold soup rich in phytochemicals, is associated with lower blood pressure (BP) and/or reduced prevalence of hypertension in individuals at high cardiovascular risk. Methods and results: We selected 3995 individuals (58% women, mean age 67 y) at high cardiovascular risk (81% hypertensive) recruited into the PREDIMED study. BP, weight, and dietary and physical activity data were collected. In multivariate linear regression analyses, after adjustment, moderate and high gazpacho consumption categories were associated with reduced mean systolic BP of 1.9 mm Hg [95% confidence interval (CI): 3.4; 0.6] and 2.6 mm Hg (CI: 4.2; 1.0), respectively, and reduced diastolic BP of 1.5 mm Hg (CI: 2.3; 0.6) and 1.9 mm Hg (CI: 2.8; 1.1). By multiple-adjusted logistic regression analysis, gazpacho consumption was associated with a lower prevalence of hypertension, with OR Z 0.85 (CI: 0.73; 0.99) for each 250 g/week increase and OR Z 0.73 (CI: 0.55; 0.98) for high gazpacho consumption groups compared to the no-consumption group. Conclusions: Gazpacho consumption was inversely associated with systolic and diastolic BP and prevalence of hypertension in a cross-sectional Mediterranean population at high cardiovascular risk. The association between gazpacho intake and reduction of BP is probably due to synergy among several bioactive compounds present in the vegetable ingredients used to make the recipe.

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Hypertension is a major public health problem and a leading cause of death and disability in both developed and developing countries, affecting onequarter of the world"s adult population. Our aim was to evaluate whether the consumption of gazpacho, a Mediterranean vegetable-based cold soup rich in phytochemicals, is associated with lower blood pressure (BP) and/or reduced prevalence of hypertension in individuals at high cardiovascular risk. Methods and results: We selected 3995 individuals (58% women, mean age 67 y) at high cardiovascular risk (81% hypertensive) recruited into the PREDIMED study. BP, weight, and dietary and physical activity data were collected. In multivariate linear regression analyses, after adjustment, moderate and high gazpacho consumption categories were associated with reduced mean systolic BP of 1.9 mm Hg [95% confidence interval (CI): 3.4; 0.6] and 2.6 mm Hg (CI: 4.2; 1.0), respectively, and reduced diastolic BP of 1.5 mm Hg (CI: 2.3; 0.6) and 1.9 mm Hg (CI: 2.8; 1.1). By multiple-adjusted logistic regression analysis, gazpacho consumption was associated with a lower prevalence of hypertension, with OR Z 0.85 (CI: 0.73; 0.99) for each 250 g/week increase and OR Z 0.73 (CI: 0.55; 0.98) for high gazpacho consumption groups compared to the no-consumption group. Conclusions: Gazpacho consumption was inversely associated with systolic and diastolic BP and prevalence of hypertension in a cross-sectional Mediterranean population at high cardiovascular risk. The association between gazpacho intake and reduction of BP is probably due to synergy among several bioactive compounds present in the vegetable ingredients used to make the recipe.

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Macrophage migration inhibitory factor (MIF) has recently been implicated in the pathogenesis of malarial anaemia. However, field studies have reported contradictory results on circulating MIF concentrations in patients with clinically overt Plasmodium falciparum malaria. We determined plasma MIF levels over time in 10 healthy volunteers during experimental P. falciparum infection. Under fully controlled conditions, MIF levels decreased significantly during early blood-stage infection and reached a nadir at day 8 post-infection. A decrease in the number of circulating lymphocytes, which are an important source of MIF production, paralleled the decrease in MIF levels. Monocyte/macrophage counts remained unchanged. At MIF nadir, the anti-inflammatory cytokine interleukin (IL)-10, which is an inhibitor of T-cell MIF production, was detectable in only 2 of 10 volunteers. Plasma concentrations of the pro-inflammatory cytokines IL-8 and IL-1beta were only marginally elevated. We conclude that circulating MIF levels decrease early in blood-stage malaria as a result of the decline in circulating lymphocytes.

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The study area. located north of Konva (Central Turkey), is composed of Silurian to Cretaceous metamorphosed rocks. The lower unit of the oldest formation (Silurian-Early Permian) is mostly made up of Silurian-Early Carboniferous metacarbonates. These rocks pass laterally and vertically to Devonian-Early Permian series having continental margin, shallow water and pelagic characteristics. They are intruded or juxtaposed to different kinds of metamagmatic rocks. which show MORB. continental arc and within plate characteristics. The Palaeozoic units are covered unconformably by Triassic-Cretaceous metasedimentary units. All these rocks are overthrusted by Mesozoic ophiolites. The Palaeozoic sequence can be seen as a northern Palaeotethys passive, then active margin. The northward subduction of the Palaeotethys ocean during the Carboniferous-Triassic times, induced the development of a magmatic arc and fore-arc sequence (Carboniferous-Permian). Before the Early Triassic (?Late Permian) time. the fore-arc sequence was uplifted above sea level and eroded. The Triassic sequences are regarded as marking the onset of back-arc opening and detachment of the Anatolian Konya block from the active Eurasian margin. Finally. a suture zone formed during the Carman between the Konya region and the Menderes-Tauride Cimmerian block due to the closing of Palaeotethvs. This geodynamic evolution can be correlated with the evolution of the Karaburun sequence in western Turkey.