34 research outputs found
Multiproxy characterization of high energy layers in the nner continental shelf of Quarteira (Southern Portugal) - Preliminary results
The occurrence of sedimentary layers indicating high energy events is common in the continental
shelves sedimentary record. Their presence has been usually related either to tsunami waves or storm
waves. In both cases, the identification of the transport mechanism requires a variety of proxies. This
work presents the preliminary results of the analysis of a gravity core (MW-107) collected at ca. 57 m
water depth in the inner continental shelf of Quarteira (Algarve) and aims to identify potential high
energy events.IPMA-2020-011-BIinfo:eu-repo/semantics/publishedVersio
Chemical factors controlling the steady-state distribution of mixed carbonate-siliciclastic sediments in Bayona Bay (northwest Spain)
The relative space distributions of single mineral constituents in mixed terrigenous-carbonated sediments of the Bayona Bay have been analysed. In order to determine the existence of different mixing mechanisms, a study comparing the general sedimentary trends resulting from the average patterns and the single mineral behaviour, reflected in the single-mineral mapping, was carried out. The relative abundance of all mineral phases in surface sediment samples was first determined by quantitative X-ray powder diffraction data, using the Rietveld method. This procedure enabled us to create specific maps for both the minerals forming the terrigenous fraction and the different calcium carbonate polymorphs involved in the carbonatic component. A cross-linked behaviour between the carbonate facies and the terrigenous minerals involved in the calcium carbonate generation was found, suggesting the existence of a chemical control mechanism which, through dissolution-crystallization processes, constrains the mixed environment's long-term evolution. In the general framework of the region studied, these relations operate for the relative amount of plagioclase to calcium carbonate. The existence of dissolution and growth between both minerals, favoured by the high rate of removal, is proposed, yielding a final crossed pattern, representative of the steady-state. Furthermore, a specific analysis, restricted to the region of low rate of material removal and maximum amount of intermixed sediments, clearly shows an anisotropic distribution for every calcium carbonate polymorph (calcite and aragonite). These correlate with the biotite distribution, and can be connected to local variations in seawater Mg/Ca ratio, induced by biotite weathering.En este trabajo se analiza de forma especĂfica la distribuciĂłn espacial de cada uno de los minerales involucrados en sedimentos mixtos terrĂgenos-carbonatados de la bahĂa de Bayona y se compara con la distribuciĂłn global de sedimentos, tal como resulta de anĂĄlisis granulomĂ©tricos, con el fin de determinar la existencia de diferentes mecanismos de mezcla entre los minerales de ambas fracciones. El contenido porcentual en peso de cada fase mineral, en muestras superficiales de sedimento, se determinĂł a partir de datos cuantitativos de DRX, empleando el mĂ©todo de Rietveld. Este procedimiento nos ha permitido realizar mapas especĂficos de distribuciĂłn, tanto para cada mineral de la fracciĂłn terrĂgena como para cada uno de los diferentes polimorfos de carbonato cĂĄlcico en la componente carbonatada. Como resultado de este estudio comparativo, se ha encontrado una correlaciĂłn, en la distribuciĂłn espacial y granulomĂ©trica, de las facies carbonatadas y los minerales terrĂgenos implicados en la generaciĂłn de carbonato cĂĄlcico. Un posterior anĂĄlisis de este resultado sugiere la presencia de mecanismos quĂmicos de control que regulan la interacciĂłn entre siliciclastos y carbonatos mediante procesos de disoluciĂłn-cristalizaciĂłn mediados por el agua del mar. El estudio se ha realizado a dos escalas. En el ĂĄmbito general de la bahĂa de Bayona, las relaciones de distribuciĂłn observadas entre plagioclasas y carbonato cĂĄlcico pueden ser explicadas, dentro del balance global del CaÂłâș disuelto en el agua del mar, mediante la meteorizaciĂłn quĂmica de las plagioclasas y la consiguiente generaciĂłn de carbonatos. En este caso, los patrones de distribuciĂłn reflejan la aproximaciĂłn a un estado estacionario mediante sucesivos eventos de mezcla asociados a la alta removilizaciĂłn material en el medio, tanto para la distribuciĂłn porcentual en peso como para la distribuciĂłn granulomĂ©trica entre ambos minerales. Finalmente, se realiza un anĂĄlisis particularizado en una regiĂłn con baja tasa de removilizaciĂłn y donde la interacciĂłn entre sedimentos de ambas fracciones es mĂĄxima. El resultado muestra claramente una distribuciĂłn espacial anisĂłtropa para cada uno de las fases de carbonato cĂĄlcico (calcita y aragonito). La abundancia relativa de cada uno de los polimorfos, asĂ como el contenido en MgÂłâș de la calcita, ha sido correlacionado con la distribuciĂłn de la biotita y explicado a partir de las diferencias de solubilidad en funciĂłn de la alta relaciĂłn MgÂłâș /CaÂłâș en el agua de mar que resulta, localmente, de la meteorizaciĂłn quĂmica de dicho mineral.Instituto Español de OceanografĂ
COVID-19 outbreaks in a transmission control scenario: challenges posed by social and leisure activities, and for workers in vulnerable conditions, Spain, early summer 2020
Severe acute respiratory syndrome coronavirus 2 community-wide transmission declined in Spain by early May 2020, being replaced by outbreaks and sporadic cases. From mid-June to 2 August, excluding single household outbreaks, 673 outbreaks were notified nationally, 551 active (>6,200 cases) at the time. More than half of these outbreaks and cases coincided with: (i) social (family/friendsâ gatherings or leisure venues) and (ii) occupational (mainly involving workers in vulnerable conditions) settings. Control measures were accordingly applied
Outcomes from elective colorectal cancer surgery during the SARS-CoV-2 pandemic
This study aimed to describe the change in surgical practice and the impact of SARS-CoV-2 on mortality after surgical resection of colorectal cancer during the initial phases of the SARS-CoV-2 pandemic
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Dietary αâLinolenic Acid, Marine Ïâ3 Fatty Acids, and Mortality in a Population With High Fish Consumption: Findings From the PREvenciĂłn con DIeta MEDiterrĂĄnea (PREDIMED) Study
Background: Epidemiological evidence suggests a cardioprotective role of αâlinolenic acid (ALA), a plantâderived Ïâ3 fatty acid. It is unclear whether ALA is beneficial in a background of high marine Ïâ3 fatty acids (longâchain nâ3 polyunsaturated fatty acids) intake. In persons at high cardiovascular risk from Spain, a country in which fish consumption is customarily high, we investigated whether meeting the International Society for the Study of Fatty Acids and Lipids recommendation for dietary ALA (0.7% of total energy) at baseline was related to allâcause and cardiovascular disease mortality. We also examined the effect of meeting the society's recommendation for longâchain nâ3 polyunsaturated fatty acids (â„500 mg/day). Methods and Results: We longitudinally evaluated 7202 participants in the PREvenciĂłn con DIeta MEDiterrĂĄnea (PREDIMED) trial. Multivariableâadjusted Cox regression models were fitted to estimate hazard ratios. ALA intake correlated to walnut consumption (r=0.94). During a 5.9ây followâup, 431 deaths occurred (104 cardiovascular disease, 55 coronary heart disease, 32 sudden cardiac death, 25 stroke). The hazard ratios for meeting ALA recommendation (n=1615, 22.4%) were 0.72 (95% CI 0.56â0.92) for allâcause mortality and 0.95 (95% CI 0.58â1.57) for fatal cardiovascular disease. The hazard ratios for meeting the recommendation for longâchain nâ3 polyunsaturated fatty acids (n=5452, 75.7%) were 0.84 (95% CI 0.67â1.05) for allâcause mortality, 0.61 (95% CI 0.39â0.96) for fatal cardiovascular disease, 0.54 (95% CI 0.29â0.99) for fatal coronary heart disease, and 0.49 (95% CI 0.22â1.01) for sudden cardiac death. The highest reduction in allâcause mortality occurred in participants meeting both recommendations (hazard ratio 0.63 [95% CI 0.45â0.87]). Conclusions: In participants without prior cardiovascular disease and high fish consumption, dietary ALA, supplied mainly by walnuts and olive oil, relates inversely to allâcause mortality, whereas protection from cardiac mortality is limited to fishâderived longâchain nâ3 polyunsaturated fatty acids. Clinical Trial Registration URL: http://www.Controlled-trials.com/. Unique identifier: ISRCTN35739639
DegradaciĂłn ambiental debido a la actividad minera en la Selva AmazĂłnica Venezolana por el uso de mercurio para la extracciĂłn de oro y evaluaciĂłn de materiales sorbentes para establecer medidas de remediaciĂłn.
ColecciĂłn AQ (Aquilafuente)27. 5 p