674 research outputs found

    Suelos volcanicos endurecidos

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    In the sedimentary basin of Rieti (Central Italy) a Mollic Fragiudalf was studied in order to verify, through the analysis of differential dissolution kinetics of Si and Al, wether the presence of this two elements could be involved in determining the fragic characters of its deep horizons. The reuslts of the main physico-chemical analysis confirmed the fragic features of the deep horizons Bt3x and Ctgx which have been already observed in the field study. Differential dissolution of Si and Al was performed using 0,5 N NaOH at 25°C, and the values of silica and alumina obtained after each of ten consecutive extractions were cumulated to trace the cumulative curves of dissolution. Slope changes of the curves, which indicate changes in dissolution rate, allowed os to recognize three mineralogical phases with different degree of solubility. The total quantity of SiO2 and Al2O3 dissolved in all the extractions and relative to each of these three phases was estimated, by a graphic method, together with SiO2(Al2O3 molar ratio. This one was indicative of the mineralogical composition and behaviour of each horizon. This study showed an accumulation of free silica which could be present in the form of phytoliths or diatoms as well as a fine precipitate of opal-A and silica-gel in the whole soil, mainly in teh Ap and Ctgx horizons. Moreover neogenesis of clay was more evident in Bt3x horizon. The volcanic origin of the parent material, a trachytic ash fall, probably deposited in a lacustrine environment, could have favoured the availability of Si and the authigenic formation of halloysitic clay from the weathering of galss and feldspars. Our study therefore corroborates the findings of previous studies by Chadwick et al. (1987) and Karathanasis (1989) indicating the important role played by silica, probably as bonding agent, in contributing to produce characteristics of a fragipan. (Résumé d'auteur)

    Halloysite formation through in situ weathering of volcanic glass from trachytic pumices, Vico's volcano, Italy

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    L'étude minéralogique et pétrographique d'une ponce trachytique provenant des coulées pyroclastiques du volcan de Vico (Italie centrale) montre que l'altération des verres produit essentiellement une halloysite bien cristallisée avec conservation de leur texture. Les auteurs discutent les caractéristiques minéralogiques et structurales de cette argil

    Matemática,1º ano, 5ª edição, 1934.

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    O livro possui dimensões 220 mm X 160 mm, 394 páginas. O exemplar pertence ao acervo do GHEMAT na cidade de Osasco- SP. Doado pela professora Circe Dynnikov.O livro destina-se ao uso de professores e traz considerações teóricas e práticas de abordagens de conteúdos de matemática para o ensino primário. São temas tratados: numeração, adição subtração, multiplicação, divisão, potencia de número, múltiplo e divisor, números primos, frações, álgebra etc

    Model testing of radioactive contamination Cs-137 of soils and bottom sediments in the Romachka river (Tomsk region, Russia)

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    This paper presents results of testing models for the radioactive contamination of river water and bottom sediments by 137Cs. The scenario for the model testing is based on data from the Romashka River, which was contaminated as a result of accidents at the Siberian Chemical Combine (Russia, Region of Tomsk). The input data include the following: estimates of inventories of 137Cs in the floodplain of the downstream part of Romashka River; the estimated annual runoff of 137Cs from the downstream part of Romachka River; data on the precipitation, hydrological and hydrochemical characteristics of the river. The endpoints of the scenario are model predictions of the activity concentrations of 137Cs in water and bottom sediments along the Romachka River in 2012-2013. Calculations for the Romashka scenario were performed by the Institute of radioprotection and nuclear safety (model CASTEAUR and HAMSTER. As a whole, the radionuclide predictions for137Cs for all considered models. At the same time the CASTEAUR model estimate the activity concentrations of 137Cs and in water more precisely than in bottom sediments

    Geriatric Patient Safety Indicators Based on Linked Administrative Health Data to Assess Anticoagulant-Related Thromboembolic and Hemorrhagic Adverse Events in Older Inpatients: A Study Proposal.

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    Frail older people with multiple interacting conditions, polypharmacy, and complex care needs are particularly exposed to health care-related adverse events. Among these, anticoagulant-related thromboembolic and hemorrhagic events are particularly frequent and serious in older inpatients. The growing use of anticoagulants in this population and their substantial risk of toxicity and inefficacy have therefore become an important patient safety and public health concern worldwide. Anticoagulant-related adverse events and the quality of anticoagulation management should thus be routinely assessed to improve patient safety in vulnerable older inpatients. This project aims to develop and validate a set of outcome and process indicators based on linked administrative health data (ie, insurance claims data linked to hospital discharge data) assessing older inpatient safety related to anticoagulation in both Switzerland and France, and enabling comparisons across time and among hospitals, health territories, and countries. Geriatric patient safety indicators (GPSIs) will assess anticoagulant-related adverse events. Geriatric quality indicators (GQIs) will evaluate the management of anticoagulants for the prevention and treatment of arterial or venous thromboembolism in older inpatients. GPSIs will measure cumulative incidences of thromboembolic and bleeding adverse events based on hospital discharge data linked to insurance claims data. Using linked administrative health data will improve GPSI risk adjustment on patients' conditions that are present at admission and will capture in-hospital and postdischarge adverse events. GQIs will estimate the proportion of index hospital stays resulting in recommended anticoagulation at discharge and up to various time frames based on the same electronic health data. The GPSI and GQI development and validation process will comprise 6 stages: (1) selection and specification of candidate indicators, (2) definition of administrative data-based algorithms, (3) empirical measurement of indicators using linked administrative health data, (4) validation of indicators, (5) analyses of geographic and temporal variations for reliable and valid indicators, and (6) data visualization. Study populations will consist of 166,670 Swiss and 5,902,037 French residents aged 65 years and older admitted to an acute care hospital at least once during the 2012-2014 period and insured for at least 1 year before admission and 1 year after discharge. We will extract Swiss data from the Helsana Group data warehouse and French data from the national health insurance information system (SNIIR-AM). The study has been approved by Swiss and French ethics committees and regulatory organizations for data protection. Validated GPSIs and GQIs should help support and drive quality and safety improvement in older inpatients, inform health care stakeholders, and enable international comparisons. We discuss several limitations relating to the representativeness of study populations, accuracy of administrative health data, methods used for GPSI criterion validity assessment, and potential confounding bias in comparisons based on GQIs, and we address these limitations to strengthen study feasibility and validity

    Increased Risk of Hospitalization for Pancreatic Cancer in the First 8 Years after a Gestational Diabetes Mellitus regardless of Subsequent Type 2 Diabetes: A Nationwide Population-Based Study.

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    The aim of this large retrospective cohort study was to use a quasi-exhaustive national medico-administrative database of deliveries in France to determine the risk of developing pancreatic cancer (PC) in women with a history of gestational diabetes mellitus (GDM). This nationwide population-based study included women aged 14-55 who gave birth between 1st January 2008 and 31 December 2009. The women were followed-up epidemiologically for eight years. Survival analyses using Cox regression models, adjusted for age, subsequent type 2 diabetes, and tobacco consumption, were performed on the time to occurrence of hospitalization for PC. The onset of GDM, tobacco consumption and subsequent type 2 diabetes were considered as time-dependent variables. Among 1,352,560 women included, 95,314 had a history of GDM (7.05%) and 126 women were hospitalized for PC (0.01%). Over the eight years of follow-up, GDM was significantly associated with a higher risk of hospitalization with PC in the first Cox regression model adjusted for age and subsequent type 2 diabetes (HR = 1.81 95% CI [1.06-3.10]). The second Cox regression model adjusted for the same covariates, plus tobacco consumption, showed that GDM was still significantly associated with a higher risk of hospitalization for PC with nearly the same estimated risk (HR = 1.77 95% CI [1.03-3.03]). Gestational diabetes was significantly associated with a greater risk of hospital admission for pancreatic cancer within eight years, regardless of subsequent type 2 diabetes

    "Aestimare" et "Aestimatio"

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