291 research outputs found

    Simple and Rapid Voltammetric Method Using a Gold Microwire Electrode to Measure Inorganic Arsenic in Holopelagic <i>Sargassum</i> (Fucales, Phaeophyceae)

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    The valorization of massive strandings of holopelagic Sargassum spp. is strongly limited by high levels of inorganic arsenic (Asi) that are potentially above the limit of current regulations. Monitoring Asi in algal biomass is currently achieved using standard chromatographic separation followed by spectroscopic detection. Here, we propose an alternative simpler procedure based on the extraction of Asi from the freeze-dried algal powder in deionized water and the electroanalytical detection of the diluted extract at a gold-microwire electrode. The protocol was optimized both in terms of extraction (powder/water ratio, extraction time, temperature) and electrolyte used for the voltammetric detection. Two electrolytes were tested: one composed of citric acid, sulfamic acid and KCl (pH 2.0) and another composed of an acetate buffer (pH 4.7) and NaCl. We demonstrate here that Asi determination is possible with the first electrolyte but it is necessary to deal with a relative unstable signal. Measurement of Asi was best achieved with the second electrolyte (acetate buffer and NaCl) with the following optimized electrochemical conditions: deposition potential of −1.2 V, deposition time of 30 seconds and linear scan voltammetry. Voltammetric results were then compared to a reference method (HPLC-ICP-MS) using different morphotypes of holopelagic Sargassum spp. (S. natans VIII, S. natans I and S. fluitans III), using commercial extracts of brown seaweeds and using a Hijiki certified reference material. Very good agreement was obtained between our novel method and HPLC-ICP-MS. Both methods show that inorganic arsenic is almost entirely present as As(V) in Sargassum spp. extracts

    Schedule for personality assessment from notes and documents (SPAN-DOC): Preliminary validation, links to the ICD-11 classification of personality disorder, and use in eating disorders

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    Background: The underlying core of personality is insufficiently assessed by any single instrument. This has led to the development of instruments adapted for written records in the assessment of personality disorder. Aims: To test the construct validity and inter-rater reliability of a new personality assessment method. Method: This study (four parts) assessed the construct validity of the Schedule for Personality Assessment from Notes and Documents (SPAN-DOC), a dimensional assessment from clinical records. We examined inter-rater reliability using case vignettes (Part 1) and convergent validity in three ways: by comparison with NEO Five-Factor Inventory in 130 Korean patients (Part 2), with agreed ICD-11 personality severity levels in two populations (Part 3) and determining its use in assessing the personality status in 90 British patients with eating disorders (Part 4). Results: Internal consistency (alpha = .90) and inter-rater reliability (intraclass correlation coefficient ≥ .88) were satisfactory. Each factor in the five-factor model of personality was correlated with conceptually valid SPAN-DOC variables. The SPAN-DOC domain traits in those with eating disorders were categorized into 3 clusters: self-aggrandisement, emotionally unstable, and anxious/dependent. Conclusions: This study provides preliminary support for the usefulness of SPAN-DOC in the assessment of personality disorder

    Midnight sun to polar night : a model of seasonal light in the Barents Sea

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    Arctic marine ecosystems are strongly influenced by the extreme seasonality of light in the region. Accurate determination of light is essential for building a comprehensive understanding of the dynamics of animal and aquatic algae populations. Current approaches to underwater light field parameterisations rely upon shortwave radiation (300–3000 nm) estimates from satellites or surface radiometry measurements to populate full radiative transfer software. Due to the inaccessibility of many regions in the Arctic, measured data is not widely available. This study presents a model of spectrally resolved underwater light in ice-free conditions in the Barents Sea. Given a location and time, the model accounts for downwelling spectral irradiance in the photosynthetically active radiation (PAR, 400–700 nm) range (E D PAR) at the ocean surface from solar, lunar, and galactic light sources, modulated by local cloud cover. We demonstrate the ability to extend over the full year into the period of Polar Night, validated in both broadband PAR and spectral domains. Using a bio-optical model of diffuse attenuation developed for the Barents Sea, we show accurate calculations to depth for inhomogeneous water columns over a spatial-temporal range, validated against time series irradiance data from the ArcLight observatory in Ny-Ålesund, Svalbard and in-situ irradiance sensors deployed in the Barents Sea. Finally, in comparison to state-of-the-art radiative transfer models, averaged over the water column we demonstrate a typical mean absolute error of <1 μmol m −2 s −1 in E D PAR for overcast conditions (<6 μmol m −2 s −1 for clear-sky) and reduced execution time of factor 20

    Recognition of Human Proinsulin Leader Sequence by Class I–Restricted T-Cells in HLA-A*0201 Transgenic Mice and in Human Type 1 Diabetes

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    OBJECTIVE— A restricted region of proinsulin located in the B chain and adjacent region of C-peptide has been shown to contain numerous candidate epitopes recognized by CD8+ T-cells. Our objective is to characterize HLA class I–restricted epitopes located within the preproinsulin leader sequence

    A procedurális emlékezet szerepe a testkép zavaraiban = The role of procedural memory in trouble of body picture

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    Az evészavarok egyik vezető betegségfenntartó tényezője a betegek torzult, diszfunkcionális kogníciója. Ezen belül is kiemelendők a táplálékfelvételi viselkedés zavaraival és a testélménnyel kapcsolatban lévő, a zavarok létrejöttében kulcsszerepet játszó kognitív disztorziók, melyek az információfeldolgozási folyamatokon belül elsősorban a perceptuális élményfeldolgozást érintik és evészavaros betegeknél a testkép speciális zavarában mutatkoznak meg. A kognitív információfeldolgozást a sémák irányítják, amelyekben a selfről való komplex tudás szerveződik. A sémák procedurális ismeretanyagot is hordoznak, úgy mint motoros készségeket, szokásokat, szabályokat, célképzeteket, döntéshozatali stratégiákat. Ezek alapján felmerül, hogy az evészavarokra jellemző viselkedéses rutincselekvések, mint például a diétázás, falásroham, önhánytatás a testkép sémáján belül procedurális élményanyagként kódolódhat és a munkamemóriában automatikusan a többi explicit tudással és emlékkel együtt aktiválódik. Elméleti áttekintésünkben ezeknek a prekognitív folyamatoknak keressük a helyét és szerepét az evészavaros betegekre jellemző kognitív információfeldolgozási jellegzetességek kialakításában

    Can Phlorotannins Purified Extracts Constitute a Novel Pharmacological Alternative for Microbial Infections with Associated Inflammatory Conditions?

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    Bacterial and fungal infections and the emerging multidrug resistance are driving interest in fighting these microorganisms with natural products, which have generally been considered complementary to pharmacological therapies. Phlorotannins are polyphenols restricted to brown seaweeds, recognized for their biological capacity. This study represents the first research on the antibacterial, antifungal, anti-inflammatory and antioxidant activity of phlorotannins purified extracts, which were obtained from ten dominant brown seaweeds of the occidental Portuguese coast

    Chemical and Microbiological Contamination in Limpet (Patella spp.) of the Portuguese Coast

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    Coastal production areas can be impacted by anthropogenic contamination from urban, agro-industrial and leisure activities. Some contaminants, such as chemical substances might also have a telluric origin. Non filter feeding univalve mollusks, such as limpets, which are collected in rocky shores either for sale or for auto-consumption, are very appreciated in Portugal, but have been excluded from provisions on the classification of production areas, although can present relevant contamination. Thus, the aim of this study was to assess the microbiological and toxic metal contaminations in limpets (Patella spp) of the Portuguese coast, taking into account the production area and seasonal variation, and comparing their contamination levels with those occurring in bivalve mollusk indicator species, mussel (Mytilus edulis). The risks associated to the consumption of limpet meals were also assessed. For that, microbial total and fecal levels and cadmium, lead and mercury contents in limpets and mussels samples from three coastal areas over several months were analyzed based on standard methodologies. Contents of mercury and lead in limpets from the three areas studied, were always below the limits of 0.50 mg kg-1 and 1.5 mg kg-1 allowed by the EU, respectively. Regarding cadmium, levels in limpet were always above the limit of 1.0 mg kg-1, reaching about 3.0 mg kg-1 in some samples. These values probably indicate contamination from telluric origin (soil or rocks) in the coastal studied areas. Results indicated that microbiological contamination of fecal origin was low and in general below the detection level. Contamination levels did not show a clear seasonal pattern. The two mollusk species, limpets and mussels, differed statistically in all contaminants analyzed, being cadmium the most of concern, and always higher in limpets than in mussel samples. Thus, the potential risk associated with limpet consumption, taking into account the cadmium tolerable weekly intake (TWI), was investigated, being possible to reach a reliable recommendation of less than a monthly meal of 160 g. As recreational picking of limpets is common in Portugal, official 4recommendations of maximum periodic human consumption should be published and enforcement increased in forbidden areasinfo:eu-repo/semantics/acceptedVersio

    Shine a light: Under-ice light and its ecological implications in a changing Arctic Ocean

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    The Arctic marine ecosystem is shaped by the seasonality of the solar cycle, spanning from 24-h light at the sea surface in summer to 24-h darkness in winter. The amount of light available for under-ice ecosystems is the result of different physical and biological processes that affect its path through atmosphere, snow, sea ice and water. In this article, we review the present state of knowledge of the abiotic (clouds, sea ice, snow, suspended matter) and biotic (sea ice algae and phytoplankton) controls on the underwater light field. We focus on how the available light affects the seasonal cycle of primary production (sympagic and pelagic) and discuss the sensitivity of ecosystems to changes in the light field based on model simulations. Lastly, we discuss predicted future changes in under-ice light as a consequence of climate change and their potential ecological implications, with the aim of providing a guide for future research

    Restraint of appetite and reduced regional brain volumes in anorexia nervosa: a voxel-based morphometric study

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    <p>Abstract</p> <p>Background</p> <p>Previous Magnetic Resonance Imaging (MRI) studies of people with anorexia nervosa (AN) have shown differences in brain structure. This study aimed to provide preliminary extensions of this data by examining how different levels of appetitive restraint impact on brain volume.</p> <p>Methods</p> <p>Voxel based morphometry (VBM), corrected for total intracranial volume, age, BMI, years of education in 14 women with AN (8 RAN and 6 BPAN) and 21 women (HC) was performed. Correlations between brain volume and dietary restraint were done using Statistical Package for the Social Sciences (SPSS).</p> <p>Results</p> <p>Increased right dorsolateral prefrontal cortex (DLPFC) and reduced right anterior insular cortex, bilateral parahippocampal gyrus, left fusiform gyrus, left cerebellum and right posterior cingulate volumes in AN compared to HC. RAN compared to BPAN had reduced left orbitofrontal cortex, right anterior insular cortex, bilateral parahippocampal gyrus and left cerebellum. Age negatively correlated with right DLPFC volume in HC but not in AN; dietary restraint and BMI predicted 57% of variance in right DLPFC volume in AN.</p> <p>Conclusions</p> <p>In AN, brain volume differences were found in appetitive, somatosensory and top-down control brain regions. Differences in regional GMV may be linked to levels of appetitive restraint, but whether they are state or trait is unclear. Nevertheless, these discrete brain volume differences provide candidate brain regions for further structural and functional study in people with eating disorders.</p

    Shearwater Foraging in the Southern Ocean: The Roles of Prey Availability and Winds

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    Background Sooty (Puffinus griseus) and short-tailed (P. tenuirostris) shearwaters are abundant seabirds that range widely across global oceans. Understanding the foraging ecology of these species in the Southern Ocean is important for monitoring and ecosystem conservation and management. Methodology/Principal Findings Tracking data from sooty and short-tailed shearwaters from three regions of New Zealand and Australia were combined with at-sea observations of shearwaters in the Southern Ocean, physical oceanography, near-surface copepod distributions, pelagic trawl data, and synoptic near-surface winds. Shearwaters from all three regions foraged in the Polar Front zone, and showed particular overlap in the region around 140°E. Short-tailed shearwaters from South Australia also foraged in Antarctic waters south of the Polar Front. The spatial distribution of shearwater foraging effort in the Polar Front zone was matched by patterns in large-scale upwelling, primary production, and abundances of copepods and myctophid fish. Oceanic winds were found to be broad determinants of foraging distribution, and of the flight paths taken by the birds on long foraging trips to Antarctic waters. Conclusions/Significance The shearwaters displayed foraging site fidelity and overlap of foraging habitat between species and populations that may enhance their utility as indicators of Southern Ocean ecosystems. The results highlight the importance of upwellings due to interactions of the Antarctic Circumpolar Current with large-scale bottom topography, and the corresponding localised increases in the productivity of the Polar Front ecosystem
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