The phytolith record from the oceanic core MD95-2043 from 20000 to 5000 years: new data on the climatic evolution of the Alboran Sea

Este estudio se centra en el análisis y estudio de los fitolitos preservados en 37 muestras de sedimentos, correspondientes al periodo comprendido entre el Último Máximo Glacial y mediados del Holoceno (20000-5000 cal ka BP), procedentes del testigo oceánico MD95-2043, recuperado en el mar de Alborán (Mediterráneo occidental) en 1995. Tras identificar las distintas morfologías de fitolitos presentes se calculó la abundancia relativa de cada una de ellas y las concentraciones totales de este grupo de microfósiles silíceos. El estudio de las condiciones ambientales requeridas por las plantas (C3 o C4) que originaron cada tipo de fitolito permite relacionar su presencia y/o abundancia con cambios en las condiciones ambientales del continente a lo largo del tiempo. Los resultados muestran la existencia de oscilaciones (más o menos graduales) en algunos parámetros como la vegetación o la humedad climática y edáfica. Por este motivo este tipo de indicadores de origen continental son una herramienta de gran utilidad para las reconstrucciones paleoclimáticas basadas en el análisis de registros sedimentariosThis study focuses on the analysis and study of phytoliths preserved in 37 sediment samples, corresponding to the period from the Last Glacial Maximum and the mid-Holocene (20000-5000 cal ka BP), from the oceanic core MD95-2043, recovered in the Alboran Sea (Western Mediterranean) in 1995. After identifying the different phytolith morphologies present in the samples, the relative abundance of each of them and the total concentrations of this group of siliceous microfossils were calculated. The study of the environmental conditions required by plants (C3 or C4) that originated each type of phytoliths allows us to relate their presence and/or abundance to changes in the continent’s environmental conditions over time. The results show the existence of certain oscillations (more or less gradual) in some parameters such as vegetation or climatic and edaphic humidity. For this reason, these type of indicators of continental origin are a very useful tool for paleoclimatic reconstructions based on the analysis of sedimentary record

Influence of 1997-98’ El Niño event on the planktonic communities from The Alboran Sea (Western Mediterranean)

The Alboran Sea is the westernmost basin of the Mediterranean Sea. Its particular location, as entrance of the Atlantic Surface Water (ASW) into the Mediterranean, has led to an intense paleoceanographic and paleoclimatic research. Nevertheless, only a limited number of studies provide information related to the dynamics and ecological characteristics of the downward particle flux. In order to determine the influence of seasonal oceanographic changes on the export of particles in the Alboran Sea, one mooring line, ALB-5-F, was deployed from July 1997 to May 1998 at 35º55.47’N/01º30.77’W. The mooring location was under the influence of the Almeria-Oran Front (AOF), which is formed by the interaction between the Atlantic jet and the denser and more saline Mediterranean waters. Information based on SeaWIFS images of chlorophyll-a concentration, current-meter, and meteorological data on wind direction and intensity were used. The annual oceanographic pattern of the AOF during the studied period was directly related to the evolution of the Western Anticyclonic Gyre (WAG) and to the 1997-98’ El Niño Event. Detailed analyses of the planktonic foraminifera, diatom and phytolith fluxes reflect seasonal changes in the main hydrographic and meteorological features in the eastern Alboran Sea. El Niño Event caused a sea surface temperature (SST) increase during fall that forced the proliferation of Globigerinoides ruber and the reduction of the diatoms. Benthic tests were also collected in the sediment trap; highest fluxes of the group were probably related to high bottom water activity. Wind-driven particles were collected along the year, but their fluxes follow the local wind regim

Traumatic brain injury and acute kidney injury - outcomes and associated risk factors

Our objective was to analyze the contribution of acute kidney injury (AKI) to the mortality of isolated TBI patients and its associated risk factors. Observational, prospective and multicenter registry (RETRAUCI) methods were used, from March 2015 to December 2019. Isolated TBI was defined as abbreviated injury scale (AIS) ≥ 3 head with no additional score ≥ 3. A comparison of groups was conducted using the Wilcoxon test, chi-square test or Fisher's exact test, as appropriate. A multiple logistic regression analysis was conducted to analyze associated risk factors in the development of AKI. For the result, overall, 2964 (30.2%) had AIS head ≥ 3 with no other area with AIS ≥ 3. The mean age was 54.7 (SD 19.5) years, 76% were men, and the ground-level falls was 49.1%. The mean ISS was 18.4 (SD 8). The in-hospital mortality was 22.2%. Up to 310 patients (10.6%) developed AKI, which was associated with increased mortality (39% vs. 17%, adjusted OR 2.2). Associated risk factors (odds ratio (OR) (95% confidence interval)) were age (OR 1.02 (1.01?1.02)), hemodynamic instability (OR 2.87 to OR 5.83 (1.79-13.1)), rhabdomyolysis (OR 2.94 (1.69-5.11)), trauma-associated coagulopathy (OR 1.67 (1.05-2.66)) and transfusion of packed red-blood-cell concentrates (OR 1.76 (1.12-2.76)). In conclusion, AKI occurred in 10.6% of isolated TBI patients and was associated with increased mortality

Impact of iceberg melting on Mediterranean thermohaline circulation during Heinrich events

Down-core samples of planktonic and benthic foraminifera were analyzed for oxygen and carbon isotopes in International Marine Past Global Changes Study (IMAGES) core MD99-2343 in order to study the interactions between climate change in the Northern Hemisphere and the western Mediterranean thermohaline circulation at times of Heinrich events (HE). Our results confirm the antiphase correlation between enhanced North Atlantic Deep Water formation and low ventilation in the Mediterranean. However, this study reveals that this antiphase relationship in deepwater formation between the North Atlantic and Mediterranean was interrupted during times of HE when the injection of large volumes of water from melting icebergs reached the entrance to the Mediterranean. These events, which lasted less than 1000 years, are represented by pronounced decreases in both planktonic d18O and benthic d13C signals. Lower salinities of Mediterranean surface water resulted in a slowdown of western Mediterranean deepwater overturn even though cold sea surface temperatures and drier climate should have resulted in enhanced deepwater formation

Plan de contingencia para los servicios de medicina intensiva frente a la pandemia COVID-19

In January 2020, the Chinese authorities identified a new virus of the Coronaviridae family as the cause of several cases of pneumonia of unknown aetiology. The outbreak was initially confined to Wuhan City, but then spread outside Chinese borders. On 31 January 2020, the first case was declared in Spain. On 11 March 2020, The World Health Organization (WHO) declared the coronavirus outbreak a pandemic. On 16 March 2020, there were 139 countries affected. In this situation, the Scientific Societies SEMICYUC and SEEIUC, have decided to draw up this Contingency Plan to guide the response of the Intensive Care Services. The objectives of this plan are to estimate the magnitude of the problem and identify the necessary human and material resources. This is to provide the Spanish Intensive Medicine Services with a tool to programme optimal response strategies

A Shift in the Biogenic Silica of Sediment in the Larsen B Continental Shelf, Off the Eastern Antarctic Peninsula, Resulting from Climate Change

5 pages, 4 figuresIn 2002, section B of the Larsen ice shelf, off of the Eastern Antarctic Peninsula, collapsed and created the opportunity to study whether the changes at the sea surface left evidence in the sedimentary record. Biogenic silica is major constituent of Antarctic marine sediment, and its presence in the sediment column is associated with diatom production in the euphotic zone. The abundance of diatom valves and the number of sponge spicules in the biogenic silica was analyzed to determine how the origin of the biogenic silica in the upper layers of the sediment column responded to recent environmental changes. Diatom valves were present only in the upper 2 cm of sediment, which roughly corresponds to the period after the collapse of the ice shelf. In contrast, sponge spicules, a more robust form of biogenic silica, were also found below the upper 2 cm layer of the sediment column. Our results indicate that in this region most of the biogenic silica in the sedimentary record originated from sponge spicules rather than diatoms during the time when the sea surface was covered by the Larsen ice shelf. Since the collapse of the ice shelf, the development of phytoplankton blooms and the consequent influx of diatom debris to the seabed have shifted the biogenic silica record to one dominated by diatom debris, as occurs in most of the Antarctic marine sediment. This shift provides further evidence of the anthropogenic changes to the benthic habitats of the Antarctic and will improve the interpretation of the sedimentary record in Polar Regions where these events occur. © 2013 Sañé et al.Peer Reviewe

Sedimentary response to Solar Cyclicity in the Gerlache Strait (Antartic Peninsula)

The Gerlache Strait (Antarctic Peninsula) is a semi-enclosed basin that acts as a giant sedimentary trap collecting large amounts of material. Previous biogenic and glacial deposits are the main suppliers of sediments. The basin is also an area of high sea-surface productivity, mostly restricted to the summer months of December and January. In this study we present micropaleontological and geochemical data obtained from a set of four sediment cores obtained by the Spanish research vessel Hespérides during the Fruela-96 expedition. The cores were collected using a multiple corer allowing recovery of up to eight replicates, with core lengths ranging between 32 and 34 cm. The stratigraphic framework of the cores, based in 210Pb activity, shows that there has been a continuous sedimentation in the sites during the last 220 years BP. The diatom assemblage varies between absolute values of 0.9 to 240 x 108 valves/g of dry sediment. Chaetoceros RS are the main contributor showing values from 66 to 90 %. The Thalassiosira antarctica/ scotia group and Sea-ice taxa, mainly Fragilariopsis curta, are secondary contributors. The total abundance of diatoms and the content of biogenic silica are interpreted as paleoproductivity proxies. In this sense, a progressive reduction in paleoproductivity is observed towards the core top, with a sharp minimum around 100 yr B.P. Moreover an increase of Sea-ice Taxa is observed for the last 100 yr. These changes could be related to the onset of a neoglacial event during this period. In order to evaluate the cyclicity record, Spectral analyses (Multi-Tapered Method) were performed on different parameters (TOC, Opal, total diatom abundance, Sea-ice Taxa and T. antarctica). The time series study shows two main types of cyclicities, 80-90 and 20-30 years in two cores, G4 and G5, both recovered from central Gerlache Strait. This cyclicity seems to be in agreement with the Hale (22 years) and the Gleissberg (83 years) Solar Cycles. Both cycles are related to strong solar eruptive activity, which modulate the amplitude of the 11-year sunspot cycle (Schawe Cycle); this cycle was also recognised in our recor

Sedimentary response to Solar Cyclicity in the Gerlache Strait (Antartic Peninsula)

38ª Sesión Científica, 2005, Teruel.-- 4 pages, 3 figures, 1 tableThe Gerlache Strait (Antarctic Peninsula) is a semi-enclosed basin that acts as a giant sedimentary trap collecting large amounts of material. Previous biogenic and glacial deposits are the main suppliers of sediments. The basin is also an area of high sea-surface productivity, mostly restricted to the summer months of December and January. In this study we present micropaleontological and geochemical data obtained from a set of foursediment cores obtained by the Spanish research vessel Hespérides during the Fruela-96 expedition. Thecores were collected using a multiple corer allowing recovery of up to eight replicates, with core lengths ranging between 32 and 34 cm. The stratigraphic framework of the cores, based in 210Pb activity, shows that there has been a continuous sedimentation in the sites during the last 220 years BP. The diatom assemblage varies between absolute values of 0.9 to 240 x 108 valves/g of dry sediment. Chaetoceros RS are the main contributor showing values from 66 to 90 %. The Thalassiosira antarctica/scotia group and Sea-ice taxa, mainly Fragilariopsis curta, are secondary contributors. The total abundance of diatoms and the content of biogenic silica are interpreted as paleoproductivity proxies. In this sense, a progressive reduction in paleoproductivity is observed towards the core top, with a sharp minimum around 100 yr B.P. Moreover an increase of Sea-ice Taxa is observed for the last 100 yr. These changes could be related to the onset of a neoglacial event during this period. In order to evaluate the cyclicity record, Spectral analyses (Multi-Tapered Method) were performed on different parameters (TOC, Opal, total diatom abundance, Sea-ice Taxa and T. antarctica). The time series study shows two main types of cyclicities, 80-90 and 20-30 years in two cores, G4 and G5, both recovered from central Gerlache Strait. This cyclicity seems to be in agreement with the Hale (22 years) and the Gleissberg (83 years) Solar Cycles. Both cycles are related to strong solar eruptive activity, which modulate the amplitude of the 11-year sunspot cycle (Schawe Cycle); this cycle was also recognised in our recordEste trabajo ha sido financiado por el Ministerio de Educación y Ciencia mediante el contrato Ramón y Cajal (nº contrato 13749957) y el proyecto REN2003-09622-C02-02Peer Reviewe

Holocene neoglacial events in the Bransfield Strait (Antarctica). Paleogeographic and paleoclimatic significance

The morphological characterisation of the western submarine island flanks of El Hierro and La Palma differentiates four type-zones that may give new insights into the evolution of oceanic island slopes. The different type-zones result from the interplay between constructive volcanic processes, hemipelagic settling and volcano collapses. The latter results in massive debris avalanche deposits, which form large volcaniclastic aprons. In most cases, the headwall scarps are clearly exposed on the emerged part of the islands. The events that occurred in the youngest and westernmost islands of El Hierro and La Palma have vertical runouts exceeding 6,000 m and volumes that can reach several hundred km3. The landslide frequency for the entire Canaries is one major event per 90 ka. Triggering mechanisms are closely related to magmatic processes. The increase in the shear stress is directly linked with the forceful intrusion of magma along ridge-rift systems, while in the western Canary Islands it seems that the main process reducing shear resistance may be related to the rise in pore pressure due to hydrothermal circulation