303 research outputs found
Demersal and epibenthic communities of sedimentary habitats in the Avilés Canyon System, Cantabrian Sea (NE Atlantic)
The aim of this study was to describe the epibenthic and demersal communities of the AvilĂ©s Canyon System (ACS) in relation to the environmental variables that characterize their biotope. ACS (Cantabrian Sea, NE Atlantic) was recently included in the Natura 2000 network as a Site of Community Importance (SCI). Data of faunal biomass derived from 6 surveys carried out using beam trawl and otter trawls in 2009 and 2010 within INDEMARES and ERDEM projects. Data were divided into two groups to obtain information about the two ecological compartments: benthic and demersal. The total number of species used in this analysis ascended to 116 in the case of benthic organisms and 110 in the case of demersal. Hierarchical clustering analysis was applied to obtain groups of samples similar in terms of species composition for the two ecological components. Depth was the main discriminating factor for grouping hauls, showing high consistency of bathymetric range independently from the compartment examined. Six groups were identified by depth as follows: medium shelf (âŒ100â200 m), external shelf (âŒ150â300m), shelf break (âŒ300â400 m), upper-slope (âŒ500â700 m), upper middle-slope (âŒ700â1100 m), and lower-middle-slope (1200â1500 m). SIMPER analysis on biomass values was performed to determine the structure of the faunal assemblages observed for each group in both compartments. Using biomass values for the analysis allowed for the exploration of groups playing important roles in ecosystem functioning and energy fluxes taking place on the sedimentary bottom of this SCI. Finally, CCA analysis revealed that the main environmental drivers were depth, broad scale bathymetric position index (BPI), near-bottom salinity, sedimentary type, and dynamics related variables (Q50 phy and So). This study gives an inventory of the soft bottom assemblages along a very wide depth range (100â1500 m) inside a SCI, linking both epibenthic and demersal communities with the biotope preferences. This study contributes to fundamental knowledge on soft-bottom communities as a pre-requisite, necessary for the next steps in terms of management framework in the SCI
Geomorphology of the Avilés Canyon System, Cantabrian Sea (BayofBiscay)
The Avilés Canyon System (ACS) is a complex, structurally-controlled canyon and valley system constituted by three main canyons of different morphostructural character. They are, from east to west: La Gaviera Canyon, El Corbiro Canyon and Avilés Canyon. In addition to this ACS, a new canyon has been surveyed: Navia Canyon.
We present for the first time a high resolution multibeam map showing with great detail the morphological and structural complexity of this segment of the Cantabrian margin.
ACS presents a tectonic imprint marked by NW-SE, NNE-SSW and E-W structures. The morphology of their reaches as well as their single mouth, in addition to some rock dredges in their major valleys, demonstrates active down-slope flushing.
The continental shelf shows a flat, uniform slope with local and well defined rock outcrops south of Aviles Canyon head. Sedimentary zones are limited, showing thin unconsolidated sedimentary cover.
Strong continental margin water dynamics avoid thicker sediment deposition, being littoral sedimentary dynamics responsible for transport to the canyons heads and conduit to the Biscay Abyssal plain.
Biscay Abyssal Plain shows evidence of a strong westward current affecting the surveyed strip of this more than 10 km wide plain. Presence of two parallel deep sea channels, erosive scarps, and erosion of gully divides on the lower slope, may indicate that this is part of the distal fan at the termination of the large turbiditic system fed by Cap Ferret, Capbreton and other large canyons (Santander, Torrelavega, Lastres and Llanes) to the west of ACS.Instituto Español de OceanografĂaVersiĂłn del edito
Electrophysiological Heterogeneity of Fast-Spiking Interneurons: Chandelier versus Basket Cells
In the prefrontal cortex, parvalbumin-positive inhibitory neurons play a prominent role in the neural circuitry that subserves working memory, and alterations in these neurons contribute to the pathophysiology of schizophrenia. Two morphologically distinct classes of parvalbumin neurons that target the perisomatic region of pyramidal neurons, chandelier cells (ChCs) and basket cells (BCs), are generally thought to have the same "fast-spiking" phenotype, which is characterized by a short action potential and high frequency firing without adaptation. However, findings from studies in different species suggest that certain electrophysiological membrane properties might differ between these two cell classes. In this study, we assessed the physiological heterogeneity of fast-spiking interneurons as a function of two factors: species (macaque monkey vs. rat) and morphology (chandelier vs. basket). We showed previously that electrophysiological membrane properties of BCs differ between these two species. Here, for the first time, we report differences in ChCs membrane properties between monkey and rat. We also found that a number of membrane properties differentiate ChCs from BCs. Some of these differences were species-independent (e.g., fast and medium afterhyperpolarization, firing frequency, and depolarizing sag), whereas the differences in the first spike latency between ChCs and BCs were species-specific. Our findings indicate that different combinations of electrophysiological membrane properties distinguish ChCs from BCs in rodents and primates. Such electrophysiological differences between ChCs and BCs likely contribute to their distinctive roles in cortical circuitry in each species. © 2013 Povysheva et al
Minimising multi-centre radiomics variability through image normalisation:a pilot study
Radiomics is an emerging technique for the quantification of imaging data that has recently shown great promise for deeper phenotyping of cardiovascular disease. Thus far, the technique has been mostly applied in single-centre studies. However, one of the main difficulties in multi-centre imaging studies is the inherent variability of image characteristics due to centre differences. In this paper, a comprehensive analysis of radiomics variability under several image- and feature-based normalisation techniques was conducted using a multi-centre cardiovascular magnetic resonance dataset. 218 subjects divided into healthy (n = 112) and hypertrophic cardiomyopathy (n = 106, HCM) groups from five different centres were considered. First and second order texture radiomic features were extracted from three regions of interest, namely the left and right ventricular cavities and the left ventricular myocardium. Two methods were used to assess features' variability. First, feature distributions were compared across centres to obtain a distribution similarity index. Second, two classification tasks were proposed to assess: (1) the amount of centre-related information encoded in normalised features (centre identification) and (2) the generalisation ability for a classification model when trained on these features (healthy versus HCM classification). The results showed that the feature-based harmonisation technique ComBat is able to remove the variability introduced by centre information from radiomic features, at the expense of slightly degrading classification performance. Piecewise linear histogram matching normalisation gave features with greater generalisation ability for classification ( balanced accuracy in between 0.78 ± 0.08 and 0.79 ± 0.09). Models trained with features from images without normalisation showed the worst performance overall (balanced accuracy in between 0.45 ± 0.28 and 0.60 ± 0.22). In conclusion, centre-related information removal did not imply good generalisation ability for classification
A Case Study of available methodology for the identification of Vulnerable Ecosystems/Habitats in bottom deep-sea fisheries: Possibilities to apply this method in the NAFO Regulatory Area in order to select Marine Protected Areas
Information is critical to Ecosystem Approach and to research about Vulnerable Marine Ecosystems/Habitats
(VME/Hs), fishing impacts on habitats and ad-hoc management measures are high-priority. Therefore, this paper
presents the ECOVUL/ARPA Interdisciplinary Approach, a case study of methodology for the identification of
VME/Hs in order to advise on conservation measures such as marine protected areas (MPAs). By means of an
interactive process involving Conventional Fisheries Science, Geomorphology, Sedimentology and Benthic
Ecology, the methodology developed under the ECOVUL/ARPA project, has been useful in order to contribute to
define practical criteria to the identification of VME/Hs, to improve the knowledge about VME/Hs distribution and
the adverse impacts of bottom trawl fisheries and to produce high quality advice on habitat protection. Applying an
interdisciplinary approach, the project identified the deep-water bottom trawl fishery footprint on the Hatton Bank
Western slope (NEAFC Regulatory Area), mapped the main fishing grounds and related seabed habitats and studied
the interactions between fishing and cold-water corals. This approach was used to suggest, with high level of
precision, the spatial limits of an area closed to bottom fishing, as an essential conservation measure to protect the
cold-water corals in the framework of the Ecosystem Approach to Fisheries management. We present here the
methods used, the main results obtained and discuss on the utility of this approach and the possibilities to apply it in
the NAFO Regulatory Area, with the aim to advise on measures for reducing the interactions of bottom fishing with
sensitive high-seas habitats and to contribute to implement the UNGA recommendations about habitat conservation
Sensory hybrid host materials for the selective chromo-fluorogenic detection of biogenic amines
Pyrylium-containing mesoporous materials have been used for the chromo-fluorogenic sensing of biogenic amines in an aqueous environment.Amoros del Toro, Pedro Jose, [email protected]
Survival analysis and sentinel lymph node status in thin cutaneous melanoma: A multicenter observational study
Drosophila TIEG Is a Modulator of Different Signalling Pathways Involved in Wing Patterning and Cell Proliferation
Acquisition of a final shape and size during organ development requires a
regulated program of growth and patterning controlled by a complex genetic
network of signalling molecules that must be coordinated to provide positional
information to each cell within the corresponding organ or tissue. The mechanism
by which all these signals are coordinated to yield a final response is not well
understood. Here, I have characterized the Drosophila ortholog
of the human TGF-ÎČ Inducible Early Gene 1 (dTIEG). TIEG are zinc-finger
proteins that belong to the KrĂŒppel-like factor (KLF) family and were
initially identified in human osteoblasts and pancreatic tumor cells for the
ability to enhance TGF-ÎČ response. Using the developing wing of
Drosophila as âin vivoâ model, the dTIEG
function has been studied in the control of cell proliferation and patterning.
These results show that dTIEG can modulate Dpp signalling. Furthermore, dTIEG
also regulates the activity of JAK/STAT pathway suggesting a conserved role of
TIEG proteins as positive regulators of TGF-ÎČ signalling and as mediators of
the crosstalk between signalling pathways acting in a same cellular context
Highly Sensitive Fluorescence Probe Based on Functional SBA-15 for Selective Detection of Hg2+
An inorganicâorganic hybrid fluorescence chemosensor (DA/SBA-15) was prepared by covalent immobilization of a dansylamide derivative into the channels of mesoporous silica material SBA-15 via (3-aminopropyl)triethoxysilane (APTES) groups. The primary hexagonally ordered mesoporous structure of SBA-15 was preserved after the grafting procedure. Fluorescence characterization shows that the obtained inorganicâorganic hybrid composite is highly selective and sensitive to Hg2+ detection, suggesting the possibility for real-time qualitative or quantitative detection of Hg2+ and the convenience for potential application in toxicology and environmental science
Polymer Composites Containing Gated Mesoporous Materials for On-Command Controlled Release
Polyamidic nanofibrous membranes containing gated silica mesoporous particles, acting as carriers, are described as novel hybrid composite materials for encapsulation and on-command delivery of garlic extracts. The carrier system consists of MCM-41 solids functionalized in the outer surface, with linear polyamines (solid P1) and with hydrolyzed starch (solid P2), both acting as molecular gates. Those particles were adsorbed on electospun nylon-6 nanofibrous membranes yielding to composite materials M1 and M2. FE-SEM analysis confirmed the presence of particles incorporated on the nylon nanofibers. The release of the entrapped molecules (garlic extract) from the P1, P2, M1, and M2 materials was evaluated using cyclic voltammetry measurements. Electrochemical studies showed that at acidic pH P1 and M1 were unable to release their entrapped cargo (closed gate), whereas at neutral pH both materials release their loading (open gate). Dealing with P2 and M2 materials, in the absence of pancreatin a negligible release is observed (closed gate), whereas in the presence of enzyme the load is freely to diffuse to the solution. These newly developed composite nanomaterials, provide a homogeneous easy-to-handle system with controlled delivery and bioactive-protective features, having potential applications on pharmacology, medical and engineering fields.The authors wish to express their gratitude to the Generalitat Valenciana (Grisolia scholarship 2011/012, project PROM-ETEO/2009/016), Spanish Government (MINECO Projects AGL2012-39597-C02-01, AGL2012-39597-C02-02 and MAT2012-38429-C04-01) and the CIBER-BBN for their support. IILA thanks DISTAM and Universita degli di Milano for a specialization scholarship. We would also like to thank the Institut de Ciencia dels Materials (ICMUV) and to the Microscopy Service of the Universitat Politecnica de Valencia for technical support. We thank Roquette for the Glucidex samples.Acosta Romero, C.; PĂ©rez Esteve, E.; Fuenmayor, CA.; Benedetti, S.; Cosio, MS.; Soto Camino, J.; SancenĂłn Galarza, F.... (2014). Polymer Composites Containing Gated Mesoporous Materials for On-Command Controlled Release. ACS Applied Materials and Interfaces. 6(9):6453-6460. https://doi.org/10.1021/am405939y645364606
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