•Distribution and fluxes of total Hg have been examined in the waters of the NW Mediterranean.•Concentrations varied from 0.6 to 4.57pmolL−1 on the inner shelf, and from 0.5 to 1.5pmolL−1 at open ...sea.•The major Hg input to the Gulf of Lions is from the open sea.•In the open sea, Hg and dissolved oxygen distributions are inverse.
Ocean margins are focal regions in terms of mercury (Hg) exchanges between the continent and the open sea. The aim of this paper is to describe the distribution and partition of Hg between the gaseous, dissolved and particulate phases in the waters of the Northwestern Mediterranean (NWM) margin, in order to assess the Hg sources and exchanges within the continuum between the continental shelf (Gulf of Lions) and the open sea (Northern Gyre).
Mean (±standard deviation) of total Hg species (HgT) concentrations in unfiltered water samples were 1.52±1.00pmolL−1 (n=36) in the inner shelf, 1.09±0.15pmolL−1 (n=30) along the slope, and 1.10±0.13pmolL−1 (n=99) in the Northern Gyre. The dissolved phase (<0.45µm) average concentrations were 0.80±0.47pmolL−1 (n=37) in the inner shelf, 0.93±0.20pmolL−1 (n=4) along the slope and 0.84±0.10 (n=20) pmolL−1 in the Northern Gyre. The particulate fraction of Hg decreased very strongly seaward from around 60% on the shelf to 10–25% above the Northern Gyre. Very low dissolved HgT concentrations occurred in the inner shelf water, consistent with the results of incubation experiments, which demonstrated that shelf water is very efficient in both production and release of dissolved gaseous Hg into the atmosphere. In the North Gyre waters column HgT presents a distribution pattern inverse to that of dissolved oxygen, and a slight Hg enrichment in the deep layer (Western Mediterranean Deep Water).
The Hg from the open sea water is the largest Hg input to the Gulf of Lions (∼5.7kmolyr−1), whereas inputs from the riverine source account for ∼3.4kmolyr−1 and atmospheric deposition for less than 0.5kmolyr−1. The Hg accumulated in the sediments of the shelf is ∼4.5kmolyr−1, including 0.6–1.7kmolyr−1 in the Rhône prodelta sediments. The evasion to the atmosphere represents a Hg flux of ∼2.6kmolyr−1.
Many recent studies have focused on the automatic classification of electrocardiogram (ECG) signals using deep learning (DL) methods. Most rely on existing complex DL methods, such as transfer ...learning or providing the models with carefully designed extracted features based on domain knowledge. A common assumption is that the deeper and more complex the DL model is, the better it learns. In this study, we propose two different DL models for automatic feature extraction from ECG signals for classification tasks: A CNN-LSTM hybrid model and an attention/transformer-based model with wavelet transform for the dimensional embedding. Both of the models extract the features from time series at the initial layers of the neural networks and can obtain performance at least equal to, if not greater than, many contemporary deep neural networks. To validate our hypothesis, we used three publicly available data-sets to evaluate the proposed models. Our model achieved a benchmark accuracy of 99.92% for fall detection and 99.93% for the PTB database for myocardial infarction versus normal heartbeat classification.
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•Protein expression profiles in mussels dietarily exposed to Ag NPs for 21 d were studied in autumn and spring.•Mussels accumulated Ag in both seasons and Ag NPs were found within ...mussels digestive gland tubule cells and gills.•Protein expression profiles and associated metabolic pathways depended on season and Ag NPs exposure.•Chitinase like protein-3 and G3PDH were among differentially expressed spots identified in both seasons.•Status of gamete development should be considered when assessing effects caused by NPs in mussels.
Potential toxic effects of Ag NPs ingested through the food web and depending on the season have not been addressed in marine bivalves. This work aimed to assess differences in protein expression in the digestive gland of female mussels after dietary exposure to Ag NPs in autumn and spring. Mussels were fed daily with microalgae previously exposed for 24 h to 10 μg/L of PVP/PEI coated 5 nm Ag NPs. After 21 days, mussels significantly accumulated Ag in both seasons and Ag NPs were found within digestive gland cells and gills. Two-dimensional electrophoresis distinguished 104 differentially expressed protein spots in autumn and 142 in spring. Among them, chitinase like protein-3, partial and glyceraldehyde-3-phosphate dehydrogenase, that are involved in amino sugar and nucleotide sugar metabolism, carbon metabolism, glycolysis/gluconeogenesis and the biosynthesis of amino acids KEGG pathways, were overexpressed in autumn but underexpressed in spring. In autumn, pyruvate metabolism, citrate cycle, cysteine and methionine metabolism and glyoxylate and dicarboxylate metabolism were altered, while in spring, proteins related to the formation of phagosomes and hydrogen peroxide metabolism were differentially expressed. Overall, protein expression signatures depended on season and Ag NPs exposure, suggesting that season significantly influences responses of mussels to NP exposure.
Short-term variations of Pt concentrations and primary production indicators were compared in three contrasting coastal sites during spring bloom: (i) the Gironde Estuary mouth (SW France), (ii) the ...semi-enclosed Arcachon Bay (SW France), and (iii) the urbanized Genoa Harbor (NW Italy). At each site, surface seawater sampling and physical-chemical measurements were combined to study diel cycles (over 25 h) of dissolved Pt concentrations in seawater (PtD) and master variables reflecting primary production activity (chlorophyll-a, phaeopigments, and particulate organic carbon, POC concentrations). Plankton nets were used in all sites, providing for the first time plankton Pt concentrations (PtPK) over a whole diel cycle (Gironde Estuary mouth) and spot sampling (Arcachon Bay and Genoa Harbor) in the coastal zone. Bivalves (wild oysters or mussels), reflecting organisms at higher trophic levels, were also collected at all sites. The POC/Chl-a ratios in the collected particulate material suggested high contribution of phytoplankton to the particulate matter in the productive Gironde Estuary mouth. At this site, phytoplankton activity partly controlled Pt cycling and particle/dissolved Pt partitioning during daytime. During the night, zooplankton grazing may release Pt into the dissolved phase. These processes are partly masked by external factors such as tide or local Pt sources, especially in more confined and/or urbanized coastal water bodies such as the Arcachon Bay and the Genoa Harbor. Platinum levels in plankton and bivalves from these contrasting sites along the Atlantic and Mediterranean coasts tended to reflect the general Pt levels in seawater. These results clearly suggest that (i) Pt contamination of coastal waters and marine organisms has become a common feature in urbanized sites and (ii) Pt transfer to the marine food chain starts at the basic level of primary producers. By concentrating Pt (Bioconcentration Factor: BCF ~ 104), phytoplankton may serve as a biomonitor to assess Pt contamination in coastal environments.
•Platinum was quantified in aquatic organisms from contrasting coastal environments•Results were compared to particle/dissolved Pt partitioning and master variables•Primary production activity seems to influence Pt diel cycling•Phytoplankton may be a good biomonitor of ambient seawater Pt contamination•Higher trophic level organisms (oysters/mussels) did not show Pt biomagnification
The Art of Being Many Martin Jörg Schäfer, Vassilis S. Tsianos / Martin Jörg Schäfer, Vassilis S. Tsianos
2016, 201605, 2016-06-06, Letnik:
86
eBook
Since 2010 we have witnessed new ways of assembling, which have made the word »democracy« sound important again. These practices may not have led to the political changes we had hoped for. ...Nevertheless, we are convinced of their importance. This book wants to acknowledge them as a starting point for a new art of being many: The »many« invoke new concepts of collectivity by renegotiating their modes of participation and (self-)presentation and by rewriting rhetorical, choreographical, and material scripts of assembling. This volume is inspired and informed by the square-occupations and neighborhood assemblies of the »real democracy« movements as well as by recent explorations of the assembly form in performance art and participatory theatre.
► Ag and Cd records in river sediment support common release by former ore-treatment. ► Cd levels in oysters reflect Cd decrease in sedimentary records after 1988. ► Ag levels in oysters reach ...maximum values between 1993 and 2003. ► Ag accumulation in oysters was attributed to additional sources.
The Gironde fluvial estuarine system is impacted by historic metal pollution (e.g. Cd, Zn, Hg) and oysters (
Crassostrea gigas) from the estuary mouth have shown extremely high Cd concentrations for decades. Based on recent work (
Chiffoleau et al., 2005) revealing anomalously high Ag concentrations (up to 65
mg
kg
−1; dry weight) in Gironde oysters, we compared long-term (∼1955–2001) records of Ag and Cd concentrations in reservoir sediment with the respective concentrations in oysters collected between 1979 and 2010 to identify the origin and historical trend of the recently discovered Ag anomaly. Sediment cores from two reservoirs upstream and downstream from the main metal pollution source provided information on (i) geochemical background (upstream; Ag: ∼0.3
mg
kg
−1; Cd: ∼0.8
mg
kg
−1) and (ii) historical trends in Ag and Cd pollution. The results showed parallel concentration-depth profiles of Ag and Cd supporting a common source and transport. Decreasing concentrations since 1986 (Cd: from 300 to 11
mg
kg
−1; Ag: from 6.7 to 0.43
mg
kg
−1) reflected the termination of Zn ore treatment in the Decazeville basin followed by remediation actions. Accordingly, Cd concentrations in oysters decreased after 1988 (from 109 to 26
mg
kg
−1, dry weight (dw)), while Ag bioaccumulation increased from 38 up to 116
mg
kg
−1, dw after 1993. Based on the Cd/Ag ratio (Cd/Ag
∼
2) in oysters sampled before the termination of zinc ore treatment (1981–1985) and assuming that nearly all Cd in oysters originated from the metal point source, we estimated the respective contribution of Ag from this source to Ag concentrations in oysters. The evolution over the past 30
years clearly suggested that the recent, unexplained Ag concentrations in oysters are due to increasing contributions (>70% after 1999) by other sources, such as photography, electronics and emerging Ag applications/materials.
Daily measurements of water discharges and suspended particulate matter (SPM) concentrations and monthly sampling for trace element analyses (Cd, Zn, Pb and Cu) were conducted from 1999 to 2002 on ...the Garonne, Dordogne and Isle Rivers, the three main tributaries of the Gironde Estuary, France. Dissolved and particulate Cd, Zn, Pb and Cu concentrations in the Isle River were generally higher than those in the Garonne River, despite the known historical polymetallic pollution affecting the Lot–Garonne River system. Even if the relatively high dissolved metal concentrations in the Isle River may be of importance for the local ecosystem, metal inputs into the estuarine and coastal zones are mainly controlled by fluvial transport via the Garonne River. Characteristic element concentration ratios (e.g., Zn/Pb) in SPM and stream sediments from the Dordogne and Isle Rivers suggest two different metal source areas with distinct geochemical signals. Low Zn/Pb ratios (<
8) and low Cu/Pb ratios (<
0.8) have been attributed to upstream source zones in the Massif Central, featuring various ore deposits and mining areas. High Zn/Pb ratios were assigned to downstream sources (e.g., vineyards), partly explaining high Zn and Cu concentrations and high Cu/Pb ratios (>
0.8) in SPM. Although SPM derived from the upstream parts of the studied watersheds may greatly contribute to the observed fluvial metal transport (up to ∼
80% for Pb), the results suggest that intensive agriculture also considerably influences gross metal (e.g., Zn, Cu) fluxes into the Gironde Estuary. Relative contributions of upstream and downstream source zones may vary from one year to another reflecting hydrological variations and/or reservoir management. Monitoring fluxes and identifying distinct geochemical signals from source areas in heterogeneous watersheds may greatly improve understanding of contaminant transport to the coast.
High-resolution sampling (every 3
h) of SPM was performed during a major flood event in a heterogeneous, medium scale watershed of the Garonne-Gironde fluvial-estuarine system (the Lot River;
A
=
...10,700
km
2;
Q
=
151
m
3/s). Particulate metal and metalloid (Cd, Zn, Pb, Co, Cr, Ni, Mo, V, U, As, Sb, Th) concentrations were compared with monthly data of the same site (Temple site) obtained during 1999–2002. During the flood event, suspended particulate matter (SPM) concentrations closely followed river discharge with a maximum value (1530
mg/L) coinciding with the discharge peak (2970
m
3/s). Trace metal/metalloid concentrations showed significant temporal variations and very contrasted responses. Particulate concentrations were similar to baseline values at the beginning of the flood and mostly increased during the event, showing anticlockwise and complex shape hystereses. Comparison of SPM yield (440,000
t) and particulate metal/metalloid fluxes during the flood with annual fluxes (1999–2002) highlights the great importance of major flood events in fluvial transport. Adequate sampling frequency during floods is necessary for reliable annual flux estimates and provides geochemical signals that may greatly improve our understanding of fluvial transport processes. The scenario of SPM and metal and metalloid transport during the flood are reconstructed by combining variations of Zn, Cd and Sb concentrations, concentration ratios (e.g. Zn/Cd, As/Th, Cd/Th) and hysteresis loops. Changes in SPM and metal/metalloid transport during distinct key stages of the flood were attributed to successive dominance of different water masses transporting material from different sources (e.g. industrial point source, bed sediment from reservoirs, plain erosion). Flood management (dam flushing) clearly enhanced the remobilization of up to 30-a old polluted sediment from reservoir lakes. Sediment remobilization accounted for ∼185,000
t of SPM (i.e. 42% of the total SPM fluxes during the flood) and strongly contributed to particulate metal/metalloid transport for Cd (90%), Zn (83%) and Pb (61%). Therefore, flood management needs to be taken into consideration in future models for erosion and pollutant transport.
Oysters are considered sentinel organisms in environmental water quality monitoring programs in which cell and tissue level biomarkers are reliable tools. Copper (Cu) and silver (Ag) are present in ...relatively high concentrations in several estuaries, potentially affecting environmental and human health. Crassostrea gigas oysters were exposed during 28 days to a range of environmentally relevant concentrations of Cu and Ag alone or in mixture. Effects were studied through cell and tissue level biomarkers approach. Results indicated: changes in the Condition Index (CI), altered digestive gland epithelium and presence of histopathological alterations in the gonad and digestive gland of exposed oysters. A time-dependent increase in lipofuscin contents in exposed oysters and an increase in intralysosomal metal accumulation in digestive cells through the experiment were also recorded. The Integrative Biological Response (IBR) Index showed that even at low exposure levels, Ag and Cu can produce alterations on oysters' health status.
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•Waterborne exposure at environmentally relevant concentrations of Cu and Ag.•Interactions between metals analysed through a battery of biomarkers.•Worsening in health status identified by Integrative Biological Response Index.•Worst health status found in the mixture containing high silver concentrations.
Fall is a prominent issue due to its severe consequences both physically and mentally. Fall detection and prevention is a critical area of research because it can help elderly people to depend less ...on caregivers and allow them to live and move more independently. Using electrocardiograms (ECG) signals independently for fall detection and activity classification is a novel approach used in this paper. An algorithm has been proposed which uses pre-trained convolutional neural networks AlexNet and GoogLeNet as a classifier between the fall and no fall scenarios using electrocardiogram signals. The ECGs for both falling and no falling cases were obtained as part of the study using eight volunteers. The signals are pre-processed using an elliptical filter for signal noises such as baseline wander and power-line interface. As feature extractors, frequency-time representations (scalograms) were obtained by applying a continuous wavelet transform on the filtered ECG signals. These scalograms were used as inputs to the neural network and a significant validation accuracy of 98.08% was achieved in the first model. The trained model is able to distinguish ECGs with a fall activity from an ECG with a no fall activity with an accuracy of 98.02%. For the verification of the robustness of the proposed algorithm, our experimental dataset was augmented by adding two different publicly available datasets to it. The second model can classify fall, daily activities and no activities with an accuracy of 98.44%. These models were developed by transfer learning from the domain of real images to the medical images. In comparison to traditional deep learning approaches, the transfer learning not only avoids “reinventing the wheel,” but also presents a lightweight solution to otherwise computationally heavy problems.
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