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Letteratura scientifica selezionata sul tema "Eels"

Autore: Grafiati

Pubblicato: 4 giugno 2021

Ultima modifica: 1 agosto 2024

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Articoli di riviste sul tema "Eels"

BUTCHER, M. "Eel-traps without Eels". Journal of Design History 10, n. 4 (1 gennaio 1997): 417–29. http://dx.doi.org/10.1093/jdh/10.4.417.

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Catania, Kenneth C. "An Optimized Biological Taser: Electric Eels Remotely Induce or Arrest Movement in Nearby Prey". Brain, Behavior and Evolution 86, n. 1 (2015): 38–47. http://dx.doi.org/10.1159/000435945.

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Despite centuries of interest in electric eels, few studies have investigated the mechanism of the eel's attack. Here, I review and extend recent findings that show eel electric high-voltage discharges activate prey motor neuron efferents. This mechanism allows electric eels to remotely control their targets using two different strategies. When nearby prey have been detected, eels emit a high-voltage volley that causes whole-body tetanus in the target, freezing all voluntary movement and allowing the eel to capture the prey with a suction feeding strike. When hunting for cryptic prey, eels emit doublets and triplets, inducing whole-body twitch in prey, which in turn elicits an immediate eel attack with a full volley and suction feeding strike. Thus, by using their modified muscles (electrocytes) as amplifiers of their own motor efferents, eel's motor neurons remotely activate prey motor neurons to cause movement (twitch and escape) or immobilization (tetanus) facilitating prey detection and capture, respectively. These results explain reports that human movement is ‘frozen' by eel discharges and shows the mechanism to resemble a law-enforcement Taser.

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Catania, Kenneth. "The shocking predatory strike of the electric eel". Science 346, n. 6214 (4 dicembre 2014): 1231–34. http://dx.doi.org/10.1126/science.1260807.

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Electric eels can incapacitate prey with an electric discharge, but the mechanism of the eel’s attack is unknown. Through a series of experiments, I show that eel high-voltage discharges can activate prey motor neurons, and hence muscles, allowing eels to remotely control their target. Eels prevent escape in free-swimming prey using high-frequency volleys to induce immobilizing whole-body muscle contraction (tetanus). Further, when prey are hidden, eels can emit periodic volleys of two or three discharges that cause massive involuntary twitch, revealing the prey’s location and eliciting the full, tetanus-inducing volley. The temporal patterns of eel electrical discharges resemble motor neuron activity that induces fast muscle contraction, suggesting that eel high-voltage volleys have been selected to most efficiently induce involuntary muscle contraction in nearby animals.

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Tambets, Meelis, Einar Kärgenberg, Ain Järvalt, Finn Økland, Martin Lykke Kristensen, Anders Koed e Priit Bernotas. "Migrating silver eels return from the sea to the river of origin after a false start". Biology Letters 17, n. 9 (settembre 2021): 20210346. http://dx.doi.org/10.1098/rsbl.2021.0346.

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The European eel's singular spawning migration from European waters towards the Sargasso Sea remains elusive, including the early phase of migration at sea. During spawning migration, the movement of freshwater resident eels from river to sea has been thought to be irreversible. We report the first recorded incidents of eels returning to the river of origin after spending up to a year in the marine environment. After migrating to the Baltic Sea, 21% of the silver eels, tagged with acoustic transmitters, returned to the Narva River. Half returned 11–12 months after moving to the sea, with 15 km being the longest upstream movement. The returned eels spent up to 33 days in the river and migrated to the sea again. The fastest specimen migrated to the outlet of the Baltic Sea in 68 days after the second start—roughly 1300 km. The surprising occurrence of returning migrants has implications for sustainable management and protection of this critically endangered species.

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Catania, Kenneth C. "Electric Eels Wield a Functional Venom Analogue". Toxins 13, n. 1 (10 gennaio 2021): 48. http://dx.doi.org/10.3390/toxins13010048.

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In this paper, I draw an analogy between the use of electricity by electric eels (Electrophorus electricus) to paralyze prey muscles and the use of venoms that paralyze prey by disrupting the neuromuscular junction. The eel’s strategy depends on the recently discovered ability of eels to activate prey motor neuron efferents with high-voltage pulses. Usually, eels use high voltage to cause brief, whole-body tetanus, thus preventing escape while swallowing prey whole. However, when eels struggle with large prey, or with prey held precariously, they often curl to bring their tail to the opposite side. This more than doubles the strength of the electric field within shocked prey, ensuring maximal stimulation of motor neuron efferents. Eels then deliver repeated volleys of high-voltage pulses at a rate of approximately 100 Hz. This causes muscle fatigue that attenuates prey movement, thus preventing both escape and defense while the eel manipulates and swallows the helpless animal. Presumably, the evolution of enough electrical power to remotely activate ion channels in prey efferents sets the stage for the selection of eel behaviors that functionally “poison” prey muscles.

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Catania, Kenneth C. "Electric Eels Wield a Functional Venom Analogue". Toxins 13, n. 1 (10 gennaio 2021): 48. http://dx.doi.org/10.3390/toxins13010048.

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Shuai, Fangmin, Xinhui Li, Wanling Yang, Weitao Chen e Sovan Lek. "Habitat use of the Japanese eel (Anguilla japonica) and marbled eel (Anguilla marmorata) in the large subtropical Pearl River". Annales de Limnologie - International Journal of Limnology 57 (2021): 8. http://dx.doi.org/10.1051/limn/2021001.

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Anguilla spp. are catadromous fish and with a high economic value in Asia. The Pearl River is the largest river in southern China and is an important area for wild populations of Anguilla spp. However, until now, there has been little research on the eel's population structure and habitat use in the Pearl River. This study analyzed the population structure and habitat use characteristics of the Japanese eel (Anguilla japonica) and the marbled eel (Anguilla marmorata) in the Pearl River based on data collected from 2015 to 2018. A total of 181 Japanese eels and 56 marbled eels were collected, over half of which were middle-sized eels between 255 and 600 mm in length. Although they are sister species, Japanese eels mainly inhabit complex river habitats characterized by high river fractals and coefficients of fluvial facies, while marbled eels mainly inhabit wider and deeper river sections. The impact of physical environmental factors (such as river fractals, coefficients of fluvial facies and river width) on the distribution of these two species is greater than the impact of small-scale water quality environmental factors (such as DO concentration, temperature and clarity). The results of this study showed that wild Anguilla spp. resources in the Pearl River were extremely low and there was an urgent need for conservation and management of eel resources in south China.

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Barić, Oliver, Tena Radočaj, Alexis Conides, Nevena Kitanović, Jurica Jug-Dujaković e Ana Gavrilović. "Functional Morphology as an Indicator of European Eel Population Status". Diversity 15, n. 12 (17 dicembre 2023): 1223. http://dx.doi.org/10.3390/d15121223.

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In the area of the Neretva delta in the eastern Adriatic, where the European eel, Anguilla anguilla (Linnaeus, 1758) has been traditionally fished for centuries, a decline in its population has been observed, as in most of Europe. Despite several studies, systematic monitoring was not performed, and the causes of population decline are attributed to anthropogenic stressors, mainly overfishing and interventions that disrupt the migration. With the stock at a low level, there is a need for a detailed assessment of biological data and the determination of the “zero state” of the eel population in the areas where monitoring was not previously performed, such as the Neretva delta. This data would serve as a basis for the development of an appropriate monitoring and eel management plan. One of the under-researched aspects is still the eel’s morphology, which is closely related to all basic life functions. The aim of this work was to analyze in detail the morphological parameters of yellow and silver eels from the mouth of the Neretva River in different seasons and the relationships between the measured morphometric parameters and physiological indicators and to compare them with previously published results for different life stages across Europe. The samples were collected during spring, summer and autumn of 2021, and winter of 2022. Yellow eels were present in the catch throughout the sampling period, while silver eels were caught in the autumn and winter. Yellow and silver eels were significantly different regarding 22 morphometric measures that were analyzed. Isometric growth was recorded for yellow eels in the spring and autumn of 2021, and positive allometric growth was recorded for yellow eels in the summer and silver eels in the autumn of 2021 and winter of 2022. PCA showed that the main factor that separates the eels grouped by life stage in different seasons is the intestine length (IL), whereas the rest of the factors (weight—W; intestine weight—IW; liver weight—LW; and total length—TL) affect the groupings almost equally. Seasonal averages of the condition factor (CF) for yellow and silver eels did not differ statistically. Three indicators were used to describe intestine morphology: relative gut weight (RGW), relative gut length (RGL), and Zihler’s index (ZHI); and the only statistically significant difference between yellow and silver eels was recorded for the RGW. The hepatosomatic index (HSI) was significantly different between silver eels in winter and yellow eels in spring. In addition to supplementing the already known facts, this paper provides new information on the functional morphology of the European eel. Monitoring of these characteristics is crucial for management of the European eel fisheries as they are directly related to functional performance and affect the ability to maintain sustainable populations in anthropogenically altered environments.

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MÜLLER, ULRIKE K., JORIS SMIT, EIZE J. STAMHUIS e JOHN J. VIDELER. "HOW THE BODY CONTRIBUTES TO THE WAKE IN UNDULATORY FISH SWIMMING". Journal of Experimental Biology 204, n. 16 (15 agosto 2001): 2751–62. http://dx.doi.org/10.1242/jeb.204.16.2751.

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SUMMARY Undulatory swimmers generate thrust by passing a transverse wave down their body. Thrust is generated not just at the tail, but also to a varying degree by the body, depending on the fish's morphology and swimming movements. To examine the mechanisms by which the body in particular contributes to thrust production, we chose eels, which have no pronounced tail fin and hence are thought to generate all their thrust with their body. We investigated the interaction between body movements and the flow around swimming eels using two-dimensional particle image velocimetry. Maximum flow velocities adjacent to the eel's body increase almost linearly from head to tail, suggesting that eels generate thrust continuously along their body. The wake behind eels swimming at 1.5Ls-1, where L is body length,consisted of a double row of double vortices with little backward momentum. The eel sheds two vortices per half tail-beat, which can be identified by their shedding dynamics as a start—stop vortex of the tail and a vortex shed when the body-generated flows reach the `trailing edge' and cause separation. Two consecutively shed ipsilateral body and tail vortices combine to form a vortex pair that moves away from the mean path of motion. This wake shape resembles flow patterns described previously for a propulsive mode in which neither swimming efficiency nor thrust is maximised but sideways forces are high. This swimming mode is suited to high manoeuvrability. Earlier recordings show that eels also generate a wake reflective of maximum swimming efficiency. The combined findings suggest that eels can modify their body wave to generate wakes that reflect their propulsive mode.

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Williams, Alan, Deborah Osterhage, Franziska Althaus, Timothy Ryan, Mark Green e John Pogonoski. "A Very Large Spawning Aggregation of a Deep-Sea Eel: Magnitude and Status". Journal of Marine Science and Engineering 9, n. 7 (30 giugno 2021): 723. http://dx.doi.org/10.3390/jmse9070723.

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Multiple lines of evidence substantiate the existence of a very large aggregation of the basketwork eel, Diastobranchus capensis, on the small (3 km2) Patience Seamount off southeast Australia. The aggregation appears to be present year-round, but largest in the austral autumn when composed of spawning eels. Twenty eels caught in April 2015 (14 female, 6 male) were all in advanced stages of spawning condition. The eel’s abundance in the aggregation was very high as measured at seamount, local and regional scales. Hydroacoustic measurement of the spawning aggregation’s dimensions (~100 × 1000 m) and conservative counts of 100 s of eels along camera transects of ~1000–2000 m length indicate 10,000 s individual eels may have been present. The absence of other known spawning locations indicates the Patience Seamount is a regional-scale spatial anchor for spawning. The aggregation was protected in a marine park in 2007 following a decades-long impact from bottom trawling, indicating that the population can be expected to stabilise and recover. Monitoring the aggregation’s status, and validating seasonal spawning, provide important opportunities to examine conservation-led recovery in the deep sea as part of Australia’s new national strategy of Monitoring, Evaluation, Reporting and Improvement (MERI) for conservation values within marine parks.

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Tesi sul tema "Eels"

Larkin, Brendan, e mikewood@deakin edu au. "The weaning and growth of Anguilla australis glass eels and elvers". Deakin University. School of Ecology and Environment, 2000. http://tux.lib.deakin.edu.au./adt-VDU/public/adt-VDU20060713.113837.

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Anguilla australis glass eels proved to be resilient and present strong aquaculture potential. General husbandry techniques, anaesthesia and prophylactic treatments were established for glass eels between 0.1 g and 2.0 g and elvers between 2.0 g and 8.0 g, caught in rivers and estuaries along the South East Coast of Victoria. The protozoan parasites Ichthyobodo and Trichodina were found to be present on arrival to the hatchery developed during different rearing treatments, and were successfully eradicated. A. australis glass eels accepted artificial food, but it was recommended first be fed a preweaning diet of minced fish flesh. A weaning regime from minced fish flesh to commercially available eel grower mash, over 15 days was established. Growth rate proved to be highly variable, both between and within groups. The highest growth rate of 2.71%/day was found when the natural diet of minced fish and Artemia was fed. The maximum growth rate when reared on an artificial diet of 1.63%/day was observed at 25°C. Growth was affected by the presence or absence of a preweaning diet, weaning diet, weaning period, temperature, but not by size or density. Once weaned, glass eels were found to perform better on commercially available grower mash than on the minced fish flesh, which was used to aid in weaning them to artificial diets. Of the water quality parameters measured stocking density was found to affect pH, Total Ammonia Nitrogen, Total Phosphorus, and Dissolved Oxygen, through not to an extent which affected growth.

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Birrell, Lynne M. "Osmoregulation in glass eels and elvers of the European eel, Anguilla anguilla". Thesis, University of St Andrews, 1999. http://hdl.handle.net/10023/14934.

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Glass eels of the European eel migrate from coastal waters inland to freshwater as part of the catadromous lifecycle. The osmotic challenge faced at this time is augmented by their large surface area to volume ratio, and by the fact that the migration may only be completed after several attempts, due to the effects of tide and river flow. Glass eels and elvers developed normally when maintained in waters of differing salinity over a six month period. Drinking rates increased with environmental acclimation salinity (from 0.072 +/- 0.023 mul/g/h to 0.698 +/- 0.099 mul/g/h in FW and SW respectively), and freshwater acclimated fish exhibited a rapid drinking response upon contact with seawater. These accounts of dipsogenic behaviour are similar to those previously reported for adult eels. Results obtained from determinations of branchial Na+K+ATPase activities were more equivocal. Only after nearly five months were activities higher in SW (508.52 +/- 99.76 nmoles/Spairs gills/h) as compared to FW fish (151.65 +/- 8.9 nmoles/5pairs gills/h). Following the transfer of FW acclimated fish to SW there was a trend towards increased Na+K+ATPase activity after seven days post-transfer, which reached a significant peak after two months post-transfer. A transient increase in whole body cortisol content was noted following the transfer of fish from freshwater (388.02 + 90.38 pg/g) to seawater (6268.44 +/- 773.14 pg/g). However, it was not possible to ascertain that this was due to a direct effect of environmental salinity change. There were no clear changes in interrenal cell morphology between salinity groups, although the cells did appear reduced in size with time, regardless of environmental salinity. Total body Na+ content increased with time, and was higher in SW (58.66 +/- 1.66 mumoles/g) as compared to FW reared fish (44.85 +/-1.01 mumoles/g).

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Kolodzie, Annette Therese. "EELS at dislocations in diamond". Thesis, University of Cambridge, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.615749.

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Juergensen, Lars Stephen. "Tissue enzyme changes in air-exposed American eels". Thesis, University of Ottawa (Canada), 1997. http://hdl.handle.net/10393/4280.

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American eels (Anguilla rostrata) are known to leave the water for excursions onto land despite lacking specialized air breathing organs. Other studies have established that the eel suffers from acidosis and hypoxemia as a result of this air exposure, but the survival of the eels despite these conditions demonstrates a large degree of tolerance to these effects. This thesis will investigate the changes in tissue enzymes of the American eel as a result of air exposure. It is the hypothesis of this experiment that conditions of air exposure eels will undergo a metabolic reorganization including an initial Pasteur effect and metabolic depression indicated by changes in enzyme activities and metabolite concentrations. Eels were air exposed for 3, 5 or 10 days in boxes ensuring constant temperature and humidity. Maximal activities were determined in white muscle, gill and posterior kidney tissues harvested immediately following the particular air exposure period; as a result of technical difficulties, liver was unavailable for study. Enzymes assayed included those key in glycolysis (PFK, PK, LDH), glycogen metabolism (GPase and GSase) and gluconeogenesis (GDH, AspAT, AlaAT, and PEPCK). In addition, kinetic analysis was undertaken for PFK and PK in harvested posterior kidney. Blood collected at the time of harvest was analyzed for glucose, lactate and cortisol to determine circulating levels. Muscle samples were also analyzed for glycogen content. Although changes in enzyme rates, enzyme kinetics and metabolites were observed to result from the air exposure, it could not be concluded that the changes were part of a concerted metabolic depression.

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Torruella, Besa Pau. "Development of novel EELS methods to unveil nanoparticle properties". Doctoral thesis, Universitat de Barcelona, 2019. http://hdl.handle.net/10803/666906.

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[eng] The aim of this thesis has been two-fold. First, to develop new processing and analysis tools and strategies for extracting information from EELS data, and second, to apply the methods to different nanoparticle systems to shed light to relevant phenomena related to their synthesis and properties. In this regard, chapter 1 presented and overview of the EELS fundamentals and of the state of the art of the technique. Chapter 2 was focused on the advanced computational methods related to EELS data analysis. Moreover, the application of cluster analysis to EELS was introduced, showing its possibilities as an image segmenting and phase identification tool. The following chapters were devoted to the investigation of different material science problems related to NPs that take advantage of the capabilities of quantitative EELS. The results were grouped by increasing complexity of the performed analysis, with chapter 3 devoted to characterizations that were mainly carried out using EELS elemental mapping, chapter 4 being related to ELNES analysis and chapter 5 to EELS tomography. In chapter 2, the adaptation of data clustering algorithms to the analysis of EELS data, developed within the scope of the present thesis, has been undertaken. In chapter 3.1 the organic synthesis of FeOx@SiO2 NPs was assessed. Several findings were obtained through the HRTEM, STEM-HAADF and EELS characterization of the FeOx@SiO2 NPs at different stages of its synthesis. In chapter 3.2, concerning Au-Ag-Se and the Au-Ag-S system cation exchange reactions several findings were made. Chapter 4 was devoted to the characterization of different NPs with an emphasis on the direct observation the oxidation state of its constituents through EELS. In chapter 4.1, the synthesis of MnOx/Fe3O4 core/shell NPs was assessed. In chapter 4.2, the measurement of oxidation state at atomic resolution in spinel crystals was proposed as a method to assess cation inversion in the crystal. The necessary methods were developed and applied to iron oxide/manganese oxide core/shell NPs. Chapter 5 was devoted to the combination of EELS and tomography. In chapter 5.1 the synthesis of cobalt oxide/cobalt ferrite (CoO@CFO) core/shell NPs and cobalt oxide/manganese ferrite (CoO@MFO) NPs was investigated. Chapter 5.2 was focused on the achievement of an oxidation state-sensitive tomographic reconstruction.
[cat] L’adveniment de la nanotecnologia està portant amb ell l’aparició d’una gran quantitat de nous materials, compostos i aplicacions. En el seu desenvolupament, sovint té lloc fenomenologia sorprenent, o encara no ben entesa. Per omplir aquest forats en el nostre coneixement i poder desenvolupar noves aplicacions és de vital importància esbrinar la configuració estructural i química a nivell subnanomètric d’aquests components. Per la seva gran resolució espacial, la microscòpia electrònica de transmissió ha esdevingut una eina indispensable en aquest context. A més, en un microscopi electrònic es poden combinar una gran varietat de tècniques que poden donar una quantitat d’informació enorme. Una d’aquestes tècniques és l’espectroscòpia de pèrdua d’energia dels electrons (EELS). Aquesta tècnica ha permès en els últims anys el mapejat d’elements químics i ions columna atòmica per columna atòmica, arribant a uns dels nivells més íntims als que es pot conèixer la matèria en estat sòlid. L’objectiu d’aquesta tesi ha estat fer ús de l’EELS i d’altres tècniques emprades en microscòpia electrònica per entendre els processos químics que tenen lloc en diferents síntesis de nanopartícules. En aquest procés s’han desenvolupat també una sèrie d’eines enfocades al processat de les dades d’EELS ja sigui per a facilitar la seva interpretació, limitar problemes derivats de la seva adquisició (i. e. soroll) o calcular propietats concretes del material estudiat. A més aquesta tècnica s’ha combinat amb mètodes de reconstrucció 3D per obtenir una informació completa dels sistemes estudiats.

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Harkins, Paula. "EELS and ELNES : investigation of titanate and zirconate perovskites". Thesis, University of Glasgow, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.425162.

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Hildebrand, Heather. "Size, age composition, and upstream migration of American eels at the Millville Dam eel ladder, Shenandoah River, West Virginia". Morgantown, W. Va. : [West Virginia University Libraries], 2005. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=4377.

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Thesis (M.S.)--West Virginia University, 2005.
Title from document title page. Document formatted into pages; contains vii, 54 p. : ill. (some col.). Includes abstract. Includes bibliographical references.

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Norton, Jeremy. "Patterns and processes in helminth communities of eels (Anguilla anguilla)". Thesis, Royal Holloway, University of London, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.406531.

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Miners, John Steven. "Geochemical controls on heavy metal accumulation in Thames Estuary eels". Thesis, Birkbeck (University of London), 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.406406.

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Gonzalez, Reinaldo J. "Raman, Infrared, X-ray, and EELS Studies of Nanophase Titania". Diss., Virginia Tech, 1998. http://hdl.handle.net/10919/30605.

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Sol-gel titania particles were investigated, primarily by optical techniques, by systematically varying synthesis, sample handling, and annealing variables. The material phases investigated were amorphous titania, anatase TiO2, and rutile TiO2. Annealing-induced phase transformations from amorphous TiO2 to anatase to rutile were studied by Raman scattering, infrared reflectivity, infrared absorption, x-ray diffraction, and electron energy-loss spectroscopy (EELS). Detailed experiments were carried out on the effects of annealing on the Raman and infrared spectra of anatase nanocrystals. The frequencies of the zone-center transverse optical (TO) and longitudinal-optical (LO) phonons of anatase were determined and were used in analyzing the results obtained on composites consisting of annealed solgel particles. The TO and LO frequencies of anatase were obtained from polarization-dependent far-infrared reflectivity measurements on single crystals. These results, which determined the dielectric functions of anatase, were used to explain infrared (IR) reflectivity spectra of titania nanoparticles pressed into pellets, as well as the grazing-incidence IR reflectivity observed for titania thin films. Because of the polycrystalline character of the titania nanoparticles, the surface roughness of the pressed pellets, and the island-structure character of the thin films, effective-medium theories (appropriate for composites) were used, along with the anatase dielectric functions, to interpret the experimental results. The titania nanoparticles were prepared by the hydrolysis/condensation of Ti(OC2H5)4. A polymeric steric stabilizer was used in the sol-gel synthesis in order to prevent continued agglomeration during the condensation process. This yielded particles with a relatively narrow size distribution. The amount of water used in the reaction determines the final particle size. Particles as small as 80 nm and as large as 300 nm were used throughout this work. From the colloidal suspension, loose powders, pressed pellets, and thin films were formed. These samples were subjected to different annealing processes at temperatures ranging from room temperature up to 1000 C. Two different annealing atmospheres were used: air (oxygen-containing) and argon (no oxygen). The amorphous to anatase transformation was followed by in-situ IR transmission measurements carried out during annealing. The particles as prepared are amorphous and the anatase phase could be detected, using this sensitive IR technique, at temperatures as low as 150 C. This phase transition was shown to be particle size dependent. It was also shown that introducing the stabilizer by means of the alkoxide flask instead of the water flask (during the sol-gel synthesis) decreases the anatase to rutile transformation temperature. Loose powders were found to transform more readily than dense pellets, while island-structure films were found to be the hardest to transform. Even at 1000 C, most of these films did not transform to rutile. X-ray diffraction experiments were used to determine nanocrystal sizes in anatase samples obtained by air and argon anneals at temperatures from 300 to 800 C. A correlation was found between Raman band shape (peak position and linewidth) and crystallite size, but this correlation was different for air anneals and for argon anneals. These experiments called for an interpretation based on a stoichiometric effect rather than a finite size effect. Based on this interpretation, the as-prepared particles are slightly oxygen-deficient, with a stoichiometry corresponding to TiO1.98. In the electron energy-loss experiments, a special data-analysis technique was used to extract the EELS spectrum of the titania nanoparticles from the observed substrate-plus-particles signal. This technique successfully resolved the titania absorption-edge peak. Which was found to be momentum independent. For low electron momentum, the results were consistent with the reported optical absorption edge.
Ph. D.

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Più fonti

Libri sul tema "Eels"

Young, Ann Townsend. Eels. Beltsville, Md: National Agricultural Library, 1990.

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Sidley, John. Eels. Henlow Camp: Beekay, 1990.

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Coldiron, Deborah. Eels. Edina, Minn: ABDO Pub. Company, 2007.

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Seward, Homer. Eels. Vero Beach, Fla: Rourke Press, 1998.

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Miller, Tori. Eels. New York: Rosen Pub. Group's PowerKids Press, 2009.

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Zobel, Derek. Eels. Minneapolis, Minn: Bellwether Media, 2008.

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Stone, Lynn M. Eels. Vero Beach, Fla: Rourke Pub., 2006.

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Dyck, Sara Van. Electric eels. Minneapolis: Lerner Publications Company, 2008.

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Rothaus, Don P. Moray eels. [Plymouth, MN]: Child's World, 1996.

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Owen, Ruth. Moray eels. New York: PowerKids Press, 2014.

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Capitoli di libri sul tema "Eels"

Keast, Vicki. "Calculating EELS". In Transmission Electron Microscopy, 405–23. Cham: Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-26651-0_14.

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Bauch, Jürgen, e Rüdiger Rosenkranz. "EELS - Elektronenenergieverlustspektroskopie". In Physikalische Werkstoffdiagnostik, 74–75. Berlin, Heidelberg: Springer Berlin Heidelberg, 2017. http://dx.doi.org/10.1007/978-3-662-53952-1_37.

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van den Thillart, Guido E. E. J. M. "European Eels: Dutch Fisheries, Culture and Eel Migration". In Eels and Humans, 61–74. Tokyo: Springer Japan, 2013. http://dx.doi.org/10.1007/978-4-431-54529-3_4.

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Leapman, Richard. "EELS Quantitative Analysis". In Transmission Electron Energy Loss Spectrometry in Materials Science and The EELS Atlas, 49–96. Weinheim, FRG: Wiley-VCH Verlag GmbH & Co. KGaA, 2005. http://dx.doi.org/10.1002/3527605495.ch3.

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Arai, Shigeru. "Practical Feeding—Eels". In Nutrition and Feeding of Fish, 223–30. Boston, MA: Springer US, 1989. http://dx.doi.org/10.1007/978-1-4757-1174-5_11.

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Rhys-Taylor, Alex. "Eels and Eastenders". In Food and Multiculture, 99–117. London, UK; New York, NY, USA: Bloomsbury Academic, an imprint of Bloomsbury Publishing, P|c, [2017] | Series: Sensory studies series: Routledge, 2020. http://dx.doi.org/10.4324/9781003085423-6.

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Righton, David, e Mandy Roberts. "Eels and People in the United Kingdom". In Eels and Humans, 1–12. Tokyo: Springer Japan, 2013. http://dx.doi.org/10.1007/978-4-431-54529-3_1.

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Jellyman, Don. "Freshwater Eels and People in New Zealand: A Love/Hate Relationship". In Eels and Humans, 143–53. Tokyo: Springer Japan, 2013. http://dx.doi.org/10.1007/978-4-431-54529-3_10.

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Miller, Michael J., e John M. Casselman. "The American Eel: A Fish of Mystery and Sustenance for Humans". In Eels and Humans, 155–69. Tokyo: Springer Japan, 2013. http://dx.doi.org/10.1007/978-4-431-54529-3_11.

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McCarthy, T. Kieran. "Eels and People in Ireland: From Mythology to International Eel Stock Conservation". In Eels and Humans, 13–40. Tokyo: Springer Japan, 2013. http://dx.doi.org/10.1007/978-4-431-54529-3_2.

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Atti di convegni sul tema "Eels"

Carpenter, Kalind, Andrew Thoesen, Darwin Mick, Justin Martia, Morgan Cable, Karl Mitchell, Sarah Hovsepian et al. "Exobiology Extant Life Surveyor (EELS)". In 17th Biennial International Conference on Engineering, Science, Construction, and Operations in Challenging Environments. Reston, VA: American Society of Civil Engineers, 2021. http://dx.doi.org/10.1061/9780784483374.033.

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Monier, Etienne, Thomas Oberlin, Nathalie Brun, Marcel Tence, Maria de Frutos e Nicolas Dobigeon. "Reconstruction Of Partially Sampled EELS Images". In 2018 9th Workshop on Hyperspectral Image and Signal Processing: Evolution in Remote Sensing (WHISPERS). IEEE, 2018. http://dx.doi.org/10.1109/whispers.2018.8747104.

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Kiste, Mikael. "Momentum resolved EELS through automated procedures". In European Microscopy Congress 2020. Royal Microscopical Society, 2021. http://dx.doi.org/10.22443/rms.emc2020.1129.

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Stegmann, Heiko. "Advanced EELS Applications in Process Development". In CHARACTERIZATION AND METROLOGY FOR ULSI TECHNOLOGY 2005. AIP, 2005. http://dx.doi.org/10.1063/1.2063017.

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GAUTRON, ERIC. "MXenes surface chemistry investigated by monochromated EELS". In European Microscopy Congress 2020. Royal Microscopical Society, 2021. http://dx.doi.org/10.22443/rms.emc2020.219.

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Miller, Benjamin. "Local In Situ Temperature Mapping Using EELS". In European Microscopy Congress 2020. Royal Microscopical Society, 2021. http://dx.doi.org/10.22443/rms.emc2020.332.

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Arenal, Raul. "Monochromated EELS Analyses on N-doped NanoDiamonds". In European Microscopy Congress 2020. Royal Microscopical Society, 2021. http://dx.doi.org/10.22443/rms.emc2020.1160.

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Kurata, Hiroki. "Aloof beam valence EELS of organic crystals". In European Microscopy Congress 2020. Royal Microscopical Society, 2021. http://dx.doi.org/10.22443/rms.emc2020.1332.

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Chen, S. Y., W. Yang, G. F. Xu e C. T. Liu. "TEM EELS analysis for DRAM failure analysis". In 2021 IEEE International Symposium on the Physical and Failure Analysis of Integrated Circuits (IPFA). IEEE, 2021. http://dx.doi.org/10.1109/ipfa53173.2021.9617371.

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Yankovich, Andrew. "Visualizing strong light-matter interactions using STEM EELS". In European Microscopy Congress 2020. Royal Microscopical Society, 2021. http://dx.doi.org/10.22443/rms.emc2020.763.

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Rapporti di organizzazioni sul tema "Eels"

van Gemert, Rob, Per Holliland, Konrad Karlsson, Niklas Sjöberg e Torbjörn Säterberg. Assessment of the eel stock in Sweden, spring 2024 : fifth post-evaluation of the Swedish eel management. Department of Aquatic Resources, Swedish University of Agricultural Sciences, 2024. http://dx.doi.org/10.54612/a.4iseib7eup.

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For decades, the population of the European eel has been in severe decline. In 2007, the European Union decided on a Regulation establishing measures for the recovery of the stock, which obliged Member States to implement a national Eel Management Plan by 2009. Sweden submitted its plan in 2008. According to the Regulation, Member States shall report regularly to the EU-Commission, on the implementation of their Eel Management Plans and the progress achieved in protection and restoration. The current report provides an assessment of the eel stock in Sweden as of spring 2024, intending to feed into the national reporting to the EU in August this year. This report updates and extends previous evaluation reports by Dekker (2012, 2015) and Dekker et al. (2018, 2021). In this report, the impacts on the stock - of fishing, restocking and mortality related to hydropower generation - are assessed. Other anthropogenic impacts (climate change, pollution, increased impacts of predators, spread of parasites, disruption of migration due to disorientation after transport, and so forth) probably have an impact on the stock too, but these factors are hardly quantifiable, and no management targets have been set. For that reason, and because most factors were not included in the EU Eel Regulation, these other factors are not included in this report. Our focus is on the quantification of silver eel biomass escaping from continental waters towards the ocean (current, current potential and pristine) and mortality risks endured by those eels during their whole lifetime. The assessment is broken down on a geographical basis, with different impacts dominating in different areas (west coast, inland waters, Baltic coast). In the last decade, a break in the downward trend in glass eel recruitment has been observed, with recruitment no longer declining consistently. Whether that relates to recent protective actions, or is due to other factors, is yet unclear. Nevertheless, recruitment levels remain at historically low levels. This report contributes to the required international assessment, but does not discuss the causing factors behind the recent recruitment trend and the overall status of the stock across Europe. For the different assessment areas, results summarise as follows: On the west coast, a commercial fyke net fishery on yellow eel was exploiting the stock, until this fishery was completely closed in spring 2012. A fishery-based assessment no longer being achievable, we present trends from research surveys (fyke nets). Insufficient information is currently available to assess the recovery of the stock in absolute terms. Obviously, current fishing mortality is zero (disregarding the currently unquantifiable effect of illegal fishing), but none of the other requested stock indicators (current, current potential and pristine biomass) can be presented. The formerly exploited size-classes of the stock show a recovery in abundance after the closure of the commercial fishery, and the smaller size classes show a break in their decline in line with the recent global trend of glass eel recruitment. In order to support the recovery of the stock, or to compensate for anthropogenic mortality in inland waters, young eel has been restocked on the Swedish west coast since 2010. Noting the quantity of restocking involved, the expected effect (ca. 50 t silver eel) is relatively small, and hard to verify – in comparison to the potential natural stock on the west coast (an order of 1000 t). However, for the currently depleted stock, the contribution will likely constitute a larger share of silver eel escapement. For inland waters, this report updates the 2021 assessment, with substantial changes in methodology being the use of a new natural recruitment model, and the full separation of Trap & Transport catches from the fisheries statistics. The assessment for the inland waters relies on a reconstruction of the stock from information on the youngest eels in our waters (natural recruits, assisted migration, restocking). Based on 78 years of data on natural recruitment into 22 rivers, a statistical model is applied which relates the number of immigrating young eel caught in traps to the location and size of each river, the distance from the trap to the river mouth, and the year in which those eels recruited to continental waters as a glass eel (year class). The further into the Baltic, the larger and less numerous recruits generally are. Distance upstream comes with less numerous recruits. Using the results from the above recruitment analysis, in combination with historical data on assisted migration (young eels transported upstream within a drainage area, across barriers) and restocking (young eels imported into a river system), we have a complete overview of how many young eels recruited to Swedish inland waters. From this, the production of fully grown silver eel is estimated for every lake and year separately, based on best estimates of growth and natural mortality rates. Subtracting the catch made by the fishery (as recorded) and down-sizing for the mortality incurred when passing hydropower stations (percentwise, as recorded or using a default percentage), an estimate of the biomass of silver eel escaping from each river towards the sea is derived. Results indicate, that since 1960, the production of silver eel in inland waters has declined from over 700 to below 300 tonnes per year (t/yr). The production of naturally recruited eels is still falling; following the increase in restocking since 2010, an increase in restocking-based production is expected to be starting right around now. Gradually, restocking has replaced natural recruitment (assisted and fully natural), now making up over 90 % of the inland stock. Fisheries have taken 20-30 % of the silver eel (since the mid-1980s), while the impact of hydropower has ranged from 25 % to 60 %, depending on the year. Escapement is estimated to have varied from 72 t in the late 1990s, to 175 t in the early 2000s. The biomass of current escapement (including eels of restocked origin) is approximately 15 % of the pristine level (incl. restocked), or almost 30 % of the current potential biomass (incl. restocked). This is below the 40 % biomass limit of the Eel Regulation, and anthropogenic mortality (70 % over the entire life span in continental waters) exceeds the limit implied in the Eel Regulation (60 % mortality, the complement of 40 % survival). Mortality being that high, Swedish inland waters currently do not contribute to the recovery of the stock. The temporal variation (in production, impacts and escapement) is partly the consequence of a differential spatial distribution of the restocking of eel over the years. The original natural (not assisted) recruits were far less impacted by hydropower, since they could not climb the hydropower dams when immigrating. Since 2010, inland restocking is increasingly concentrated to drainage areas falling to the Kattegat-Skagerrak, also including obstructed lakes (primarily Lake Vänern, and many smaller ones). Even though Trap & Transport of silver eel - from above barriers towards the sea - has contributed to reducing the hydropower impact, hydropower mortality remains the largest estimated contributor to silver eel mortality in inland waters. Without restocking, the biomass affected by fishery and/or hydropower would be only 5-10 % of the currently impacted biomass, but the stock abundance would reduce from 15 % to less than 3 % of the pristine biomass. In summary: the inland eel stock biomass is below the minimum target, anthropogenic impacts exceed the minimum limit that would allow recovery, and those impacts have been increasing. It is therefore recommended to reconsider the current action plans on inland waters, taking into account the results of the current, comprehensive assessment. For the Baltic coast, the 2021 assessment has been updated without major changes in methodology. Results indicate that the impact of the fishery continues to decline over the decades. The current impact of the Swedish silver eel fishery on the escapement of silver eel along the Baltic Sea coast is estimated at 0.3 %. However, this fishery is just one of the anthropogenic impacts (in other areas/countries) affecting the eel stock in the Baltic, including all types of impacts, on all life stages and all habitats anywhere in the Baltic. Integration with the assessments in other countries has not been achieved. Current estimates of the abundance of silver eel (biomass) indicates an order of several thousand tonnes, but those estimates are extremely uncertain, due to the low impact of the fishery (near-zero statistics). Moreover, these do not take into account the origin of those silver eels, from other countries. An integrated assessment for the whole Baltic will be required to ground-truth these estimates. This would also bring the eel assessments in line with the policy to regionalise stock assessments for other (commercial) fish species (see https://ec.europa.eu/oceans-and-fisheries/fisheries/rules/multiannual-plans_en). It is recommended to develop an integrated assessment for the entire Baltic Sea eel stock, and to coordinate protective measures with other range states.

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Camden, Jon P. Application of STEM/EELS to Plasmon-Related Effects in Optical Spectroscopy. Office of Scientific and Technical Information (OSTI), gennaio 2015. http://dx.doi.org/10.2172/1168830.

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Griffioen, A. B., T. Wilkes, W. Janssen e T. Menke. Glass eel (Anguilla anguilla) predation risk byEuropean sea bass (Dicentrarchus labrax) in the lab. : Have VIE-tagged glass eels an increased predation risk? : how long can glass eels be detected in the stomach of a Sea bass? IJmuiden: Stichting Wageningen Research, Centre for Fisheries Research (CVO), 2020. http://dx.doi.org/10.18174/536393.

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Amaral, Stephen, Jenna Rackovan, Kimberly Capone, Brian McMahon, Kimbal Hall, Jacob LaFontaine, Jonathan Truebe, Eric Truebe e Corey Wright. Evaluation of Modular and Scalable Downstream Passage Systems for Silver American Eels. Office of Scientific and Technical Information (OSTI), marzo 2021. http://dx.doi.org/10.2172/1772578.

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Therese Miller, Therese Miller. Elucidating the mysterious life of New Zealand eels using environmental DNA methods. Experiment, febbraio 2024. http://dx.doi.org/10.18258/65044.

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Yazzie, Natanii. In-situ TEM EELS analysis of memristive thin films for neuromorphic computing. Office of Scientific and Technical Information (OSTI), maggio 2024. http://dx.doi.org/10.2172/2372652.

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van Rooyen, Isabella J., e Haiming Wen. STEM/EELS Study of Fission Product Transport in Neutron Irradiated TRISO Fuel Particles (NSUF report). Office of Scientific and Technical Information (OSTI), dicembre 2016. http://dx.doi.org/10.2172/1483612.

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Gallagher, Margie Lee, Gad Degani e Dan Levanon. The Effects of Culture Temperature, Age, and Growth Rate on Protein and Energy Utilization in Eels (Anquilla Sp.). United States Department of Agriculture, settembre 1985. http://dx.doi.org/10.32747/1985.7566697.bard.

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Taylor, Andrew, e James Long. Assessment of invasion extent of Asian swamp eels in ponds and backwater marshes adjacent to the Chattahoochee River: With consideration of management and control strategies. National Park Service, febbraio 2022. http://dx.doi.org/10.36967/nrr-2291487.

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Maycock, Barry, Cath Mulholland, Emma French e Joseph Shavila. Rapid Risk Assessment: What is the risk from microcystins in the edible flesh of fish caught from Lough Neagh? Food Standards Agency, marzo 2024. http://dx.doi.org/10.46756/sci.fsa.slz868.

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During the Summer and Autumn of 2023, Lough Neagh in Northern Ireland was affected by a cyanobacterial bloom. Testing of water from within the bloom reported high concentrations of one type of cyanobacterial toxin, microcystins. Samples were taken from the Lough of eels, roach, perch, pollan and bream and tested for a range of cyanobacterial toxins, including microcystins, nodularins, anatoxin, cylindrospermopsin and saxitoxin. Each sample comprised 10 fish, and five samples were taken of each species, except for bream for which a single sample was collected. The fish were dissected and the edible flesh, intestine, liver, roe, gonad and/or gills analysed separately. Microcystins were detected at a range of concentrations in the various parts of the fish that were sampled - intestine, liver, roe and/or gills, but were not detected in the edible flesh of any of the fish samples. Averaged across the samples, the highest concentrations of microcystins were quantified in the intestine samples, followed by the liver samples, with low concentrations were detected in the gills and a small number of the samples of gonads and roe. None of the other toxins were detected in any fish sample. The initial analysis for microcystins was of free toxins only. However, there is evidence that microcystins which are covalently bound to proteins are also bioavailable and therefore 22 fish tissue samples, including nine fish flesh samples, were also sent to another laboratory where they were analysed by a method which measures the total concentrations of microcystins, free and protein-bound. The viscera tissue samples chosen for the further analysis were those with the highest concentrations of the free toxins, while the fish flesh samples included 2-3 samples each of eels, roach, pollan and perch. The concentrations of total microcystins found in viscera samples were around one order of magnitude higher than the concentrations of free microcystins that had been measured. However, microcystins were still not detected in the edible fish flesh samples. It is possible that microcystins were not present at any level in any of the fish flesh samples. However, the presence of microcystins in the edible flesh of fish has been reported in the scientific literature, albeit at lower levels than those in the gastrointestinal tract or other parts of the viscera such as liver (Testai et al., 2016). Since microcystins were detected in other parts of the fish sampled from Lough Neagh it is also possible that they were also present in the fish flesh but at levels below the limits of detection of the analytical methods. The limit of detection of the analytical method for total (free + bound) microcystins was 10 µg/kg wet weight. An upper bound dietary exposure assessment was conducted. While a lower bound exposure assessment would assume the microcystins were not present in the edible flesh, i.e. a concentration of 0 µg/kg, the upper bound approach assumed they were present at the limit of detection of 10 µg/kg. The true concentrations may be between these levels. The exposure assessments consider high consumers of fish (97.5th percentile). For eels, consumption data were used from the National Diet and Nutrition Survey (NDNS). For roach, perch, pollan and bream. No consumption data were available from the NDNS and consumption data for trout were used instead as a proxy. The main target organ for toxicity of the microcystins is the liver, though other organs may also be affected. The microcystin most studied toxicologically is microcystin-LR, which is one of the most common microcystins. A WHO review established a provisional tolerable daily intake (TDI) for microcystin-LR of 0.04 µg per kg bodyweight (bw). WHO recommended that exposures to total microcystins should be compared to this provisional TDI, though there is uncertainty with this as individual microcystins are likely to differ significantly in their toxic potencies. Estimated dietary exposures of total microcystins were all within the provisional TDI, indicating no health concern from consuming the edible flesh of these species. Since fish may be caught and prepared for consumption not only by food business operators but by recreational anglers, concern has been raised that evisceration may be incomplete or the edible flesh may become contaminated in the process, and therefore this was also considered in the risk assessment. This was based on the sample of fish which contained the highest concentration of total microcystins in a viscera component, which was a sample of roach with a particularly high concentration of microcystins in intestine. It was assumed that 10% of the relative proportion of intestine to flesh in the fish would be inadvertently consumed with the flesh. In this scenario, dietary exposures would be within the provisional TDI in most age groups or would marginally exceed the TDI, but this would not be toxicologically significant. In addition, since this exposure scenario used an upper bound approach to the concentration in flesh, and used the highest concentration in any viscera sample, it is not clear that there would be any exceedance of the provisional TDI in practice. Overall, it appears unlikely that consumers will substantially exceed the provisional TDI on a long-term basis due to incomplete evisceration of fish. Overall, exposure to microcystins from eating the edible flesh of the tested fish species would not be expected to cause adverse effects in consumers, including if the fish is inadequately eviscerated. Therefore, we consider the frequency of adverse reactions in the general population to be negligible, so rare that it does not merit to be included. Based on the possible levels of exposure to microcystins from fish from Lough Neagh, it is considered that any liver injury, were it to occur in consumers of fish, would result from long term exposure and be mild. Overall, we consider the severity of illness that could potentially occur as a result of exposure to microcystins from consuming edible fish flesh from Lough Neagh to be medium (i.e. moderate illness, incapacitating but not usually life-threatening and of moderate duration). We consider the level of uncertainty to be medium (i.e. there are some but no complete data available), but that this does not affect the conclusion of the risk assessment since many of the key uncertainties are addressed within the risk assessment. However, future monitoring would be useful to assess whether microcystin concentrations in the fish change over time.

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