The Aristeia (“Excellence”) Project for the “Integrated study of trace metals biogeochemistry in the coastal marine environment”

Trace Metals have attracted significant scientific interest due to their wide dispersal in the environment, their provenance from a variety of natural and anthropogenic sources, and their toxicity to biota and humans. European Environmental issues and related policies, such as, the Marine Strategy Framework Directive (MSFD), the Water Framework Directive (WFD), the Integrated Coastal Zone Management (ICZM) Adaptation protocol, the Horizon 2020, the REACH EU regulatory framework etc., refer to trace metal distributions, speciation and behavior. The understanding the environmental biogeochemical cycling of metals that include their sources and sinks, as well as their transport and interaction patterns requires sound knowledge of their chemical speciation which is also useful for assessing the impacts of pollutants to the overall ecosystem functioning including their toxicity and bioavilability. The Aristeia (“Excellence”) project aimed to elucidate the trends in trace metal pollution of a notorious hot spot coastal areas (The Gulf of Elefsis as well as the Evoikos Gulf) and evaluate the effectiveness of measures and policies that have been applied for the reduction/prevention of pollution of the coastal zone. Furthermore we aimed to identify in detail the current environmental status of these areas including potential risks for the ecosystem and human health and compare them with past records. Finally through the Dissemination Actions we aimed to communicate these results to local stakeholders and the general public

Airborne Drones for Water Quality Mapping in Inland, Transitional and Coastal Waters—MapEO Water Data Processing and Validation

Using airborne drones to monitor water quality in inland, transitional or coastal surface waters is an emerging research field. Airborne drones can fly under clouds at preferred times, capturing data at cm resolution, filling a significant gap between existing in situ, airborne and satellite remote sensing capabilities. Suitable drones and lightweight cameras are readily available on the market, whereas deriving water quality products from the captured image is not straightforward; vignetting effects, georeferencing, the dynamic nature and high light absorption efficiency of water, sun glint and sky glint effects require careful data processing. This paper presents the data processing workflow behind MapEO water, an end-to-end cloud-based solution that deals with the complexities of observing water surfaces and retrieves water-leaving reflectance and water quality products like turbidity and chlorophyll-a (Chl-a) concentration. MapEO water supports common camera types and performs a geometric and radiometric correction and subsequent conversion to reflectance and water quality products. This study shows validation results of water-leaving reflectance, turbidity and Chl-a maps derived using DJI Phantom 4 pro and MicaSense cameras for several lakes across Europe. Coefficients of determination values of 0.71 and 0.93 are obtained for turbidity and Chl-a, respectively. We conclude that airborne drone data has major potential to be embedded in operational monitoring programmes and can form useful links between satellite and in situ observations

Indacenodithienothiophene-Based Ternary Organic Solar Cells

One of the key aspects to achieve high efficiency in ternary bulk-hetorojunction solar cells is the physical and chemical compatibility between the donor materials. Here, we report the synthesis of a novel conjugated polymer (P1) containing alternating pyridyl[2,1,3]thiadiazole between two different donor fragments, dithienosilole and indacenodithienothiophene (IDTT), used as a sensitizer in a host system of indacenodithieno[3,2-b]thiophene,2,3-bis(3-(octyloxy)phenyl)quinoxaline (PIDTTQ) and [6,6]-phenyl C70 butyric acid methyl ester (PC71BM). We found that the use of the same IDTT unit in the host and guest materials does not lead to significant changes in the morphology of the ternary blend compared to the host binary. With the complementary use of optoelectronic characterizations, we found that the ternary cells suffer from a lower mobility-lifetime (μτ) product, adversely impacting the fill factor. However, the significant light harvesting in the near infrared region improvement, compensating the transport losses, results in an overall power conversion efficiency enhancement of ~7% for ternary blends as compared to the PIDTTQ:PC71BM devices

Airborne Drones for Water Quality Mapping in Inland, Transitional and Coastal Waters-MapEO Water Data Processing and Validation

Using airborne drones to monitor water quality in inland, transitional or coastal surface waters is an emerging research field. Airborne drones can fly under clouds at preferred times, capturing data at cm resolution, filling a significant gap between existing in situ, airborne and satellite remote sensing capabilities. Suitable drones and lightweight cameras are readily available on the market, whereas deriving water quality products from the captured image is not straightforward; vignetting effects, georeferencing, the dynamic nature and high light absorption efficiency of water, sun glint and sky glint effects require careful data processing. This paper presents the data processing workflow behind MapEO water, an end-to-end cloud-based solution that deals with the complexities of observing water surfaces and retrieves water-leaving reflectance and water quality products like turbidity and chlorophyll-a (Chl-a) concentration. MapEO water supports common camera types and performs a geometric and radiometric correction and subsequent conversion to reflectance and water quality products. This study shows validation results of water-leaving reflectance, turbidity and Chl-a maps derived using DJI Phantom 4 pro and MicaSense cameras for several lakes across Europe. Coefficients of determination values of 0.71 and 0.93 are obtained for turbidity and Chl-a, respectively. We conclude that airborne drone data has major potential to be embedded in operational monitoring programmes and can form useful links between satellite and in situ observations

Airborne Drones for Water Quality Mapping in Inland, Transitional and Coastal Waters-MapEO Water Data Processing and Validation

Using airborne drones to monitor water quality in inland, transitional or coastal surface waters is an emerging research field. Airborne drones can fly under clouds at preferred times, capturing data at cm resolution, filling a significant gap between existing in situ, airborne and satellite remote sensing capabilities. Suitable drones and lightweight cameras are readily available on the market, whereas deriving water quality products from the captured image is not straightforward; vignetting effects, georeferencing, the dynamic nature and high light absorption efficiency of water, sun glint and sky glint effects require careful data processing. This paper presents the data processing workflow behind MapEO water, an end-to-end cloud-based solution that deals with the complexities of observing water surfaces and retrieves water-leaving reflectance and water quality products like turbidity and chlorophyll-a (Chl-a) concentration. MapEO water supports common camera types and performs a geometric and radiometric correction and subsequent conversion to reflectance and water quality products. This study shows validation results of water-leaving reflectance, turbidity and Chl-a maps derived using DJI Phantom 4 pro and MicaSense cameras for several lakes across Europe. Coefficients of determination values of 0.71 and 0.93 are obtained for turbidity and Chl-a, respectively. We conclude that airborne drone data has major potential to be embedded in operational monitoring programmes and can form useful links between satellite and in situ observations

Large-area spatial atomic layer deposition of amorphous oxide semiconductors at atmospheric pressure

\u3cp\u3e Indium gallium zinc oxide (IGZO) is deposited using plasma-enhanced spatial atomic layer deposition (sALD) on substrates as large as 32 × 35 cm \u3csup\u3e2\u3c/sup\u3e . Excellent uniformity and thickness control leads to high-performing and stable coplanar top-gate self-aligned (SA) thin-film transistors (TFTs). The integration of a sALD-deposited aluminum oxide buffer layer into the TFT stack further improves uniformity and stability. The results demonstrate the viability of atmospheric sALD as a novel deposition technique for the flat-panel display industry. \u3c/p\u3

Ventricular pre-excitation in the general population: a study on the mode of presentation and clinical course

OBJECTIVE—To describe the mode of presentation and the clinical course of patients with ventricular pre-excitation (Wolff-Parkinson-White (WPW) syndrome), with special emphasis on asymptomatic cases in the general population.
METHODS—Over an eight year period (1990-97) a prospective population based survey of cases with WPW pattern was conducted in a defined population in north west Greece (340 000 inhabitants). ECGs with WPW pattern were obtained from a widespread pool of ECGs within the health system.
RESULTS—During the study period, 157 cases with WPW pattern were identified (49 female, 108 male). Ages ranged from infants to 84( )years, mean (SD) 49.1 (21.0) years in female and 39.6 (20.6) years in male subjects (p < 0.01); 78 (49%) had no history of syndrome related symptoms. Asymptomatic subjects (n = 77; 24 female, 53( )male) were older than symptomatic subjects (mean age 46.7 (21.0) v 38.5 (20.6) years, p < 0.03). Documented supraventricular tachycardia was recorded in 27 patients (17%) and atrial fibrillation in 12( )(8%) (mean age at first episode 31.2 (18.3) and 51.6 (20.7) years, respectively, p < 0.01). During follow up (mean 55 months) no case of sudden death occurred. Three asymptomatic subjects reported episodes of brief palpitation.
CONCLUSIONS—WPW pattern is more common, and diagnosed at a younger age, in men than in women. About half the patients with WPW pattern on ECG are asymptomatic at diagnosis and tend to remain so thereafter. No sudden cardiac death occurred during the study period.


Keywords: Wolff-Parkinson-White syndrome; epidemiolog

Holocene climate variability and environmental changes in the NE Mediterranean Sea along a N-S transect

International audienceThe Eastern Mediterranean Sea (EMS) lies in a climatological transition zone, under the influence of both tropical and mid-latitude climate processes. Early Holocene sediment records collected in the EMS bear witnesses for the formation of the most recent sapropel S1, closely associated with distinct minima in the orbital precession cycle and the insolation-driven monsoon maxima. The different scenarios of S1 deposition involve changes in marine productivity, organic matter preservation and circulation changes and are still under debate. Herewith, we focus on combined geochemical and micropaleontological proxies, namely organic biomarkers, organic carbon and nitrogen stable isotopes and coccolithophore assemblages, aiming at reconstructing climate-related parameters such as sea surface temperature (SST), marine productivity patterns, stratification and nutricline fluctuations and continental inputs in three gravity cores collected along a north-south transect in the EMS. Depending on the water column depth, the sediment accumulation rates and the hydrographic circulation patterns, S1 deposited in our records between ~9.8 to 6.4 kyr BP. During the Holocene climatic optimum, SSTs increase gradually more than 4° C and reaches values as high as 21.2° C, 22.5° C and 23° C along the N-S transect. Our records also show a pronounced centennial-scale cooling that culminates at ~ 8.0 kyrs BP, coeval to the N. Atlantic cooling event, causing an interruption in the deposition of S1 in all sites. Moreover, SST fluctuations are detected between 4.9 and 4.1 kyr BP, with a sharp positive shift to 24.9° C indicating the presence of a warm period in the mid Holocene. Higher accumulation rates of TOC, marine biomarkers and coccolithophore assemblages were recorded during the S1a, S1b and Mid Holocene Humid (MHH) phases, indicating higher productivity and/or better preservation of organic matter. Furthermore, distribution patterns, composition and characteristic ratios of marine biomarkers and of coccolithophoride species exhibit variability in paleoproductivity trends, hydrographic dynamics and nutricline levels during the Holocene. The distributions of land plant biomarkers are indicative of variable terrigenous organic matter supply and the concomitant transport of nutrients to surface waters. The different types of δ13Corg excursions associated with stronger fluvial delivery (terrestrial inputs) in the north site, whereas the other two sites received most marine organic matter. Lighter values of δ15N within S1 and MHH phases reflect a significant contribution of N-fixing organisms to the N-cycle, related probably to higher demand for nitrogen due to the established dysoxia in the water column/sediment interface, leading to denitrification and P regeneration

A biomarker study of high resolution sedimentary records in the eastern Mediterranean Sea since the last glacial maximum

International audienceInformation stored in sedimentary records provides evidence on climate and environmental variability at decadal to centennial time scales. The eastern Mediterranean Sea and the related Aegean Sea exhibit high sedimentation rates in certain areas and are considered as sensitive regions to record paleo-environmental and -climatic changes. The aim of our study is to reconstruct high-frequency paleoclimatic variations and identify associated changes in the physical, chemical and biological environment in selected basins of the eastern Mediterranean Sea, using molecular biogeochemical proxies. Here we present a high-resolution multi-proxy study along two Aegean Sea cores (north (152SL) and southeast (NS-14)) and a Libyan Sea core (HCM2/22). An important time marker and indicator of remarkable climatic and environmental changes is sapropel S1, a sediment layer rich in organic carbon. Depending on the water column depth, the sediment accumulation rates and the proximity to freshwater and water formation sources, S1 deposited between ~9.8 to 6.4 kyr BP, with an apparent interruption in the S1 deposition that occurred from ~8.6 to 7.6 kyr BP. SSTs based on alkenone unsaturation index Uḱ 37, ^15tot, ^13Corg and various marine and terrestrial biomarkers are used to investigate the region's climatic variability, and the modifications in the biogeochemical functioning of the eastern Mediterranean Sea. Uḱ 37 SST distribution in our records reveals significant fluctuations in temperature over the last 20.000 yrs. Organic carbon stable isotopes values span a narrow range over the whole sequence, with values varying to typical marine origin. The distributions of land-plant biomarkers are indicative of variable terrigenous organic matter supply and the concomitant transport of nutrients to surface waters. Furthermore, the distribution patterns and characteristic ratios of marine biomarkers exhibit differences in the paleoproductivity trends and ventilation changes over the last 20 kyr. Low ^15N values within the sapropel layers reflect a significant contribution of N-fixation to the N-cycle, related probably to higher demand for nitrogen due to denitrification and sedimentary phosphorous regeneration processes under low-oxygen conditions

Organic carbon distribution and isotopic composition in three records from the eastern Mediterranean Sea during the Holocene

We investigated the distribution of organic carbon (TOC) and bulk organic δ13Corg values in two cores from the Aegean Sea and one from the Libyan Sea, eastern Mediterranean Sea (EMS) with a focus on the timing and regional expression of sapropel S1 deposition in the early Holocene. Our data indicate that the onset of S1 occurred earlier in the Libyan Sea (∼9.8kyr BP) than in the Aegean Sea (∼8.9kyr BP), implying that dysoxia/anoxia started earlier in the deeper sites of the EMS than in the shallower sites in the Aegean Sea. Accumulation rates of organic matter (OM) during the S1 period have a clear decreasing gradient from north to south, with higher values in the Aegean Sea and TOC contents higher in the deep basin. The three sedimentary sequences exhibit δ13Corg values that fall within the range of algal OM (-25‰ to -20‰). Shifts to lighter δ13Corg values within sapropel intervals in the Aegean sites can be interpreted as the result of elevated marine production, enhanced inflow of light terrestrial dissolved inorganic carbon and/or of the shoaling of the pycnocline, along with the presence of a deep chlorophyll maximum (DCM) during the S1 period. © 2010 Elsevier Ltd