Artykuły w czasopismach: „BLOOM CHANNEL”

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Shaika, Nowrin Akter, Eman Alhomaidi, Md Milon Sarker, Abdullah An Nur, Md Ashfaq Sadat, Sadiqul Awal, Golam Mostafa, Shanur Jahedul Hasan, Yahia Mahmud i Saleha Khan. "Winter Bloom of Marine Cyanobacterium, Trichodesmium erythraeum and Its Relation to Environmental Factors". Sustainability 15, nr 2 (10.01.2023): 1311. http://dx.doi.org/10.3390/su15021311.

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A winter bloom event of Trichodesmium erythraeum was monitored for the first time in the southeastern coastal parts of Bangladesh along the Bay of Bengal. This study presents the brownish to light pinkish bloom that appeared in mid-winter and disappeared abruptly during spring. Heavy blooms of T. erythraeum revealed the highest concentration of 91.47 ± 52.94 × 103 colonies/L in the Bakkhali River Estuary, and 66.93 ± 12.95 × 103 colonies/L in the Maheshkhali Channel of the Bay of Bengal. Three distinct morphological shapes, namely puffs, tufts and asymmetrical colonies, were depicted as major types. Several environmental factors, such as water temperature, salinity, pH, dissolved oxygen, NO3–N and PO4–P, were analyzed to determine their relationship with the occurrence, abundance and bloom formation of T. erythraeum. The abundance of the species showed a positive correlation with salinity and pH while exhibiting a negative correlation with temperature and DO. A cluster analysis revealed a clear indication of T. erythraeum bloom during winter. Thus, the prevalence of the highest density of the bloom in the present study area strongly suggests increased monitoring and research efforts in order to effectively manage or impede harmful algal blooms.

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Yang, Yong, Jinlong Han, Yue Zhang, Shizhuo Lin, Meixia Liang, Lizi Zhao i Zhizhong Song. "Genome-Wide Identification and Characterization of the Shaker-Type K+ Channel Genes in Prunus persica (L.) Batsch". International Journal of Genomics 2022 (9.03.2022): 1–11. http://dx.doi.org/10.1155/2022/5053838.

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Shaker-type K+ channels are critical for plant K+ acquisition and translocation that play key roles during plant growth and development. However, molecular mechanisms towards K+ channels are extremely rare in fruit trees, especially in peach. In this study, we identified 7 putative shaker-type K+ channel genes from peach, which were unevenly distributed on 5 chromosomes. The peach shaker K+ channel proteins were classified into 5 subfamilies, I-V, and were tightly clustered with pear homologs in the phylogenetic tree. Various cis-acting regulatory elements were detected in the promoter region of the shaker-type K+ channel genes, including phytohormone-responsive, abiotic stress-responsive, and development regulatory elements. The peach shaker K+ channel genes were expressed differentially in distinct tissues, and PpSPIK was specifically expressed in the full-bloom flowers; PpKAT1 and PpGORK were predominantly expressed in the leaves, while PpAKT1, PpKC1, and PpSKOR were majorly expressed in the roots. The peach shaker K+ channel genes were differentially regulated by abiotic stresses in that K+ deficiency, and ABA treatment mainly increased the shaker K+ channel gene expression throughout the whole seedling, whereas NaCl and PEG treatment reduced the shaker K+ channel gene expression, especially in the roots. Moreover, electrophysiological analysis demonstrated that PpSKOR is a typical voltage-dependent outwardly rectifying K+ channel in peach. This study lays a molecular basis for further functional studies of the shaker-type K+ channel genes in peach and provides a theoretical foundation for K+ nutrition and balance research in fruit trees.

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Kim, Baekjoong, Jongseok Baek, Sangjin Lee, Suna Jeong i Hyungsan Kim. "Forecast Algal Bloom in Urban Channel Using CE-QUAL-W2". Korean Society of Hazard Mitigation 17, nr 1 (28.02.2017): 375–82. http://dx.doi.org/10.9798/kosham.2017.17.1.375.

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Ozgunes, I., i B. V. K. V. Kumar. "Magneto-optic read channel modeling in the presence of bloom". IEEE Transactions on Magnetics 30, nr 6 (1994): 4410–12. http://dx.doi.org/10.1109/20.334104.

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Yang, Bao, Minglin Wang, Hui Zhang, Shuai Liu, Guobin Wang i Xuebing Wang. "Optimization of Heavy Reduction Process on Continuous-Casting Bloom". Metals 12, nr 11 (2.11.2022): 1873. http://dx.doi.org/10.3390/met12111873.

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Heavy reduction (HR) is an effective technique to control V segregation in continuous casting bloom, but the effect of segregation improvement is limited by the parameters such as reduction position and reduction amounts. In order to improve the macrosegregation of bloom, numerical simulation and plant experiments are adopted in this research. A heat transfer model and a reduction model with comprehensive thermo-physical parameters were established. The two models were verified by comparing the measured surface temperature and the theoretical strain at the solidification front. It is determined that the position of the HR of the bearing steel bloom is 20.82 m~24.97 m from the meniscus, and the solid fraction in the center of the bloom is 0.6~1. The total reduction of the HR is set to 30 mm, and the reduction of each roller in the reduction range is set to 4 mm, 5 mm, 9 mm, 7 mm, and 5 mm, respectively, to prevent the formation of internal cracks. Plant trials were conducted to verify the effect of the optimized HR. The results show that the carbon segregation degree on the V channel and non-channel of the bloom decreases from 1.2 to 1.16 and increases from 0.93 to 0.95, respectively, and the central carbon segregation degree decreases from 1.17 to 1.15. Meanwhile, the internal crack was not found in the bloom.

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Branco, S., M. Menezes, C. Alves-de-Souza, P. Domingos, MA Schramm i LAO Proença. "Recurrent blooms of Heterosigma akashiwo (Raphidophyceae) in the Piraquê Channel, Rodrigo de Freitas Lagoon, southeast Brazil". Brazilian Journal of Biology 74, nr 3 (sierpień 2014): 529–37. http://dx.doi.org/10.1590/bjb.2014.0074.

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Six blooms of Heterosigma akashiwo(Raphidophyceae) were observed from March 2007 through March 2008 in the Rodrigo de Freitas Lagoon, a semi-confined eutrophic system located in Rio de Janeiro state, southeast Brazil. Vegetative cells of H. akashiwo analysed by optical and electron microscopy showed morphology as described in the literature. The blooms (2.8 × 104 to 4 × 108 cell.L–1) were restricted to the middle section of the Piraquê Channel, which is situated in the northeastern part of the lagoon and receives freshwater inflow. The salinity of subsurface water and the channel depth showed significant negative correlations with H. akashiwo abundances, and appeared to restrict the blooms to this compartment of the lagoon. No fish mortality was associated with the H. akashiwo blooms, nor were brevetoxins detected in a cell extract obtained from the bloom observed on 19 March 2007.

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Davies, Anthony G., I. De Madariaga, Begoña Bautista, E. Fernández, D. S. Harbour, P. Serret i P. R. G. Tranter. "The ecology of a coastal Phaeocystis bloom in the north-western English Channel in 1990". Journal of the Marine Biological Association of the United Kingdom 72, nr 3 (sierpień 1992): 691–708. http://dx.doi.org/10.1017/s0025315400059452.

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The evolution of a Phaeocystis bloom off Plymouth in spring 1990 is described. Data were obtained (1) during weekly visits to station El to measure physical parameters, nutrient concentrations, primary production and grazing pressure and (2) by regular tows of an Undulating Oceanographic Recorder around a circuit of five stations including El to detect stratification, monitor the geographical distribution of chlorophyll and determine vertical profiles at each station.The data show that the Phaeocystis bloom emanated from near-shore, its spread towards the south-east correlating with the wind direction prevailing at the time. Due to bad weather, seasonal stratification had not been established at the time of the bloom so that a major diatom outburst had not occurred and nutrients remained high as the Phaeocystis moved offshore.Zooplankton populations at El, averaged over 50 m, decreased whilst Phaeocystis was present, resulting in very low grazing pressure. Termination of the bloom was not, therefore, due to consumption by herbivores. It was, instead, caused by Phaeocystis colonies becoming nutrient-depleted and releasing single cells which were transported downwards. As a result of this, chlorophyll concentrations near the bottom remained high for some time after the Phaeocystis had disappeared from the surface water.A scenario is proposed to explain the observations in terms of our current understanding of the ecophysiology of Phaeocystis.

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Zeitzschel, B. "The dynamics of organic production in the Rockall Channel area". Proceedings of the Royal Society of Edinburgh. Section B. Biological Sciences 88 (1986): 207–20. http://dx.doi.org/10.1017/s0269727000004565.

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SynopsisFor the onset of the phytoplankton spring bloom in temperate waters, the irradiance, the concentration of accumulated nutrients and the stability of the water column are of great importance. The “new” production in spring is produced mainly by chain forming diatoms.The dissipation of the spring bloom is due to nutrient depletion in the stabilised surface layer, loss of cells by sinking and grazing by herbivorous zooplankton. After the nutrient concentration is lowered, the rate of production will depend primarily on the rate of replenishment of nutrients. In open ocean environments we find “regenerated production” which is due to exudated and excreted nutrient salts e.g. ammonium. The dominating group of phytoplankters are small flagellates. It is argued that a substantial part of the phytoplankton standing stock in spring is lost from the euphotic zone due to direct sinking of cells or accelerated sinking of cell-aggregates. It is postulated that faecal pellets of micro- and mesozooplankton are retained and recycled in the mixed layer, whereas macrozooplankton faecal strings transport a considerable amount of organic matter to the benthal.

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Tew, Kwee Siong, Pei-Jie Meng, David C. Glover, Jih-Terng Wang, Ming-Yih Leu i Chung-Chi Chen. "Characterising and predicting algal blooms in a subtropical coastal lagoon". Marine and Freshwater Research 65, nr 3 (2014): 191. http://dx.doi.org/10.1071/mf13029.

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Algal bloom is a major concern worldwide. In this study, we characterised the physical and biochemical parameters during an algal bloom event in a coastal lagoon in an attempt to predict local blooms in the future. Results showed that the highest concentrations of dissolved inorganic phosphorus (DIP), chlorophyll a (chl a) and phytoplankton abundance were found in the inner area, whereas the highest dissolved inorganic nitrogen (DIN) concentration occurred near the inlet-outlet channel. Chl a was correlated with DIP, and there was a significant exponential relationship between chl a and the nitrogen to phosphorus ratio (N/P ratio) across all sampling stations and times. A higher proportion of the variation in chl a was explained by the N/P ratio than either DIP or DIN. We found that a N/P ratio <2.38 will likely trigger an algal bloom (chl a ≥ 10 µgL–1) in the lagoon. Our results suggest that the N/P ratio could be used as an expedient and reliable measure of the potential eutrophic status of coastal lagoons.

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Irigoien, X. "North Atlantic Oscillation and spring bloom phytoplankton composition in the English Channel". Journal of Plankton Research 22, nr 12 (1.12.2000): 2367–71. http://dx.doi.org/10.1093/plankt/22.12.2367.

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Brunet, C., J. M. Brylinski, L. Bodineau, G. Thoumelin, D. Bentley i D. Hilde. "Phytoplankton Dynamics During the Spring Bloom in the South-eastern English Channel". Estuarine, Coastal and Shelf Science 43, nr 4 (październik 1996): 469–83. http://dx.doi.org/10.1006/ecss.1996.0082.

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Boero, Ferdinando, Genuario Belmonte, Roberta Bracale, Simonetta Fraschetti, Stefano Piraino i Serena Zampardi. "A salp bloom (Tunicata, Thaliacea) along the Apulian coast and in the Otranto Channel between March-May 2013". F1000Research 2 (10.09.2013): 181. http://dx.doi.org/10.12688/f1000research.2-181.v1.

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Between March-May 2013 a massive Salpa maxima bloom was recorded by a citizen science study along the Ionian and Adriatic coast of the Salento peninsula (Italy). Citizen records were substantiated with field inspections along the coast and during an oceanographic campaign in the Otranto Channel.Salps clogged nets, impairing fishing activities along the coast. Swimmers were scared by the gelatinous appearance of the salps, and thought they were jellyfish. At the end of the bloom the dead bodies of the colonies, that were up to 6-7 m long, were accumulated along the coast and stirred by the waves, forming foams along dozens of kilometers of coast. The bloom also occurred at the Tremiti Islands, north of the Gargano Peninsula. The possible impacts of such events on the functioning of pelagic systems are discussed.

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Garcia-Soto, C., E. Fernández, R. D. Pingree i D. S. Harbour. "Evolution and structure of a shelf coccolithophore bloom in the Western English Channel". Journal of Plankton Research 17, nr 11 (1995): 2011–36. http://dx.doi.org/10.1093/plankt/17.11.2011.

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Polimene, L., A. Mitra, S. F. Sailley, S. Ciavatta, C. E. Widdicombe, A. Atkinson i J. I. Allen. "Decrease in diatom palatability contributes to bloom formation in the Western English Channel". Progress in Oceanography 137 (wrzesień 2015): 484–97. http://dx.doi.org/10.1016/j.pocean.2015.04.026.

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Llewellyn, C. A., i D. S. Harbour. "A temporal study of mycosporine-like amino acids in surface water phytoplankton from the English Channel and correlation with solar irradiation". Journal of the Marine Biological Association of the United Kingdom 83, nr 1 (10.01.2003): 1–9. http://dx.doi.org/10.1017/s0025315403006726h.

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A seasonal survey was undertaken, over a year, of phytoplankton from surface water in the western English Channel (Station L4) measuring mycosporine-like amino acids (MAAs), photosynthetic pigments and microscopic counts. Ground level solar radiation (ultraviolet-B, ultraviolet-A and photosynthetically active radiation; UV-B, UV-A and PAR) was measured at a nearby site. From this we estimated in situ solar irradiance received by phytoplankton using measurements of the mixed layer depth and calculations of the 50% light level cut-off. The MAAs occurred year round, with concentrations increasing rapidly during spring and summer (maximum 8·5 μg l−1) to levels exceeding those of chlorophyll-a (chl-a maximum 3·6 μg l−1). On two occasions, increases in specific MAAs coincide with algal blooms. In spring, increases in mycosporine-glycine (λmax 310 nm in the UV-B) coincide with a bloom of the prymnesiophyte Phaeocystis pouchetii and in July and August increases in an unidentified MAA (λmax 328 nm) match a bloom of the diatom, Guinardia striata (=Rhizosolenia stolterfothii). Concentration of MAAs, but not chlorophyll, correlate with in situ irradiance. The ratio of MAA to chl-a increases linearily with in situ irradiance received by phytoplankton reaching 13·9 nmol MAA (nmol chl-a)−1 at 101 W m−2. Evidence of photoinduction is observed during the P. pouchetii bloom with a four fold increase in the concentration of mycosporine-glycine (maximum 2 pg cell−1) as UV-B:PAR ratio increases from 0·0011 to 0·0014. Dinoflagellates, although contributing to <10% of biomass, are found through the correlation of MAAs to the biomarker peridinin, to contribute to baseline levels of MAAs throughout the year. Our MAA:chl-a values for the English Channel are similar to those measured in coastal areas of southern USA. Similarities with studies on Antarctic phytoplankton are also found with the dominance of porphra-334 and the presence of mycosporine-glycine in P. pouchetti.

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Schapira, Mathilde, Dorothee Vincent, Valerie Gentilhomme i Laurent Seuront. "Temporal patterns of phytoplankton assemblages, size spectra and diversity during the wane of a Phaeocystis globosa spring bloom in hydrologically contrasted coastal waters". Journal of the Marine Biological Association of the United Kingdom 88, nr 4 (25.06.2008): 649–62. http://dx.doi.org/10.1017/s0025315408001306.

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The space–time dynamic of phytoplankton diversity and succession was investigated during the wane of a Phaeocystis globosa spring bloom in four distinct hydrological sub-systems of the eastern English Channel. Nutrients, chlorophyll-a concentrations, and phytoplankton composition, standing stocks, size spectra and diversity were monitored during three key periods in 2003: late spring, early summer and summer. Two consecutive diatom assemblages were observed, respectively dominated by: (i) small colonial species (<100 μm; Melosira sp., Diploneis sp. and Navicula transitans) in April; and (ii) large fine-walled cells (>200 μm; Guinardia striata and Rhizosolenia imbricata) in May and July. This shift in diatom composition appeared to be related to the potentially limitating silicic acid in early summer. Specific phytoplankton assemblages identified in distinct water masses have evolved from a mature/senescent community towards a relatively homogeneous aestival structure of dominant species that might have been triggered by the wane of the P. globosa bloom. Our results also identified a strong heterogeneity in the distribution of secondary species between distinct water masses during the summer period, suggesting that the magnitude of the observed patterns was intrinsically related to the hydrological properties prevailing in each sub-system. The identification of distinct temporal patterns in phytoplankton species diversity and succession following the wane of a spring bloom at relatively small spatial scales (i.e. <10 km) is discussed in the framework of P. globosa blooms in particular and phytoplankton blooms in general and is suggested to have potentially strong consequences on food web dynamics and the carbon cycle in coastal ecosystems.

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Davies, Anthony G., i M. Ann Smith. "Alkaline phosphatase activity in the western English Channel". Journal of the Marine Biological Association of the United Kingdom 68, nr 2 (maj 1988): 239–50. http://dx.doi.org/10.1017/s0025315400052152.

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The spatial and vertical distributions of alkaline phosphatase activity (APA) in the western English Channel in July 1987 were determined using 2 μM 3-O-methylfluorescein phosphate as substrate. The response of APA to increases in substrate concentration followed Michaelis-Menten kinetics but differences in Ks values between stations suggested a species dependency of the half-saturation constant. Phosphate inhibition of APA was, however, similar at 3 locations. The chlorophyll specific APA (SAPA) in surface waters ranged from 0.004 to 0.57 nMPO43- μg chla-1 min-1 and was inversely exponentially related to the chlorophyll a concentration reflecting the fact that phytoplankton populations are largest where inorganic nutrient availability is greatest and synthesis of the enzyme is not derepressed. SAPA values were found to be low in the bloom of Gyrodinium aureolum in the Ushant front and in the sub-surface chlorophyll maximum in the stratified region. Vertical distributions of SAPA are discussed in terms of the hydrographic characteristics of the water column and an attempt has been made to distinguish between APA associated with phytoplankton and with bacteria.

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Aiken, Jim, James Fishwick, Gerald Moore i Katharine Pemberton. "The annual cycle of phytoplankton photosynthetic quantum efficiency, pigment composition and optical properties in the western English Channel". Journal of the Marine Biological Association of the United Kingdom 84, nr 2 (kwiecień 2004): 301–13. http://dx.doi.org/10.1017/s0025315404009191h.

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Phytoplankton photosynthetic quantum efficiency (PQE), pigments, absorption characteristics, species composition (converted to phytoplankton carbon, Cph) and other variables were measured at an offshore site in the western English Channel throughout 2001, using an opportunistic weekly sampling schedule. The variation of chlorophyll-a (Chla) and other phytoplankton pigments followed the classical seasonal cycle, driven by incident light, patterns of stratification and nutrient availability. Phytoplankton and pigment concentrations were low in the winter, rising to a peak in the spring ‘bloom’, with episodic blooms throughout the summer, an autumn bloom and a decline to the winter minimum. Surface layer Chla and total pigment (Tpig) concentrations were highly correlated for the whole year, yet it was observed that the fraction of Chla in Tpig (Chla/Tpig) was not constant and had a distinct seasonal pattern, low in winter and higher in spring, summer and autumn blooms. Chlorophyll-a/Tpig was linearly correlated with recent ambient light fluxes and maximum PQE (PQEm) throughout most of the year, though more significantly within seasonal periods. Chlorophyll-a and Tpig were both linearly correlated to Cph and the Chla/Cph ratio was significantly correlated with both Chla/Tpig and PQEm. Also the optical absorption ratios, a674/a443 and a674/a490 were significantly correlated with PQE and Chla/Tpig, indicating probable optical signatures for these two parameters. The seasonal cycle of measurements of photosynthetic quantum efficiency provided a bench-mark against which all the photosynthetically-driven seasonal changes of biological properties can be understood, in terms of incident solar radiation and nutrient availability. We conclude that phytoplankton synthesize Chla preferentially to other pigments or carbon compounds in conditions beneficial to growth. The PQEm, the ratios of Chla/Tpig, Chla/Cph and a674/a443 are greater when plants are growing actively. In periods of nutrient sufficiency, PQEm, Chla/Tpig and a674/a443 are all linear functions of the mean total photon flux for the recent few days. Photosynthetically driven changes in Chla synthesis, cause observed changes of Chla/Tpig and Chla/Cph ratios.

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Vanhoutte-Brunier, Alice, Liam Fernand, Alain Ménesguen, Sandra Lyons, Francis Gohin i Philippe Cugier. "Modelling the Karenia mikimotoi bloom that occurred in the western English Channel during summer 2003". Ecological Modelling 210, nr 4 (luty 2008): 351–76. http://dx.doi.org/10.1016/j.ecolmodel.2007.08.025.

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Garcia, V. M. T., i D. A. Purdie. "Primary production studies during a Gyrodinium cf. aureolum (Dinophyceae) bloom in the western English Channel". Marine Biology 119, nr 2 (maj 1994): 297–305. http://dx.doi.org/10.1007/bf00349569.

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Easley, Richard W., James A. Roberts, Mark G. Dunn i Charles S. Madden. "Diagnosing Consumer Information Problems: An Investigation of Deception in the Mail-Order Video Camcorder Market". Journal of Public Policy & Marketing 11, nr 2 (wrzesień 1992): 37–44. http://dx.doi.org/10.1177/074391569201100204.

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Changes in the marketing environment of mail-order retailing (e.g., widespread acceptance of credit cards, increased sales of technologically complex high ticket items, and the increasing use of toll-free numbers for inbound calls) have increased sales substantially in this retailing channel. Consequently, opportunities for deception abound. Bloom has provided a model that is useful for diagnosing information problems in consumer markets and suggests potential courses of response action contingent upon form of deception. The authors report an investigation of deception in the mail-order electronics industry and use the Bloom model as a framework for interpreting the results. The findings indicate that, in addition to consumer education about forms of deception in the market, public policy changes are needed to protect many affected publics in addition to consumers.

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Kitchen, Sheila A., Andrea J. Bourdelais i Alison R. Taylor. "Interaction of a dinoflagellate neurotoxin with voltage-activated ion channels in a marine diatom". PeerJ 6 (3.04.2018): e4533. http://dx.doi.org/10.7717/peerj.4533.

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Background The potent neurotoxins produced by the harmful algal bloom species Karenia brevis are activators of sodium voltage-gated channels (VGC) in animals, resulting in altered channel kinetics and membrane hyperexcitability. Recent biophysical and genomic evidence supports widespread presence of homologous sodium (Na+) and calcium (Ca2+) permeable VGCs in unicellular algae, including marine phytoplankton. We therefore hypothesized that VGCs of these phytoplankton may be an allelopathic target for waterborne neurotoxins produced by K. brevis blooms that could lead to ion channel dysfunction and disruption of signaling in a similar manner to animal Na+ VGCs. Methods We examined the interaction of brevetoxin-3 (PbTx-3), a K. brevis neurotoxin, with the Na+/Ca2+ VGC of the non-toxic diatom Odontella sinensis using electrophysiology. Single electrode current- and voltage- clamp recordings from O. sinensis in the presence of PbTx-3 were used to examine the toxin’s effect on voltage gated Na+/Ca2+ currents. In silico analysis was used to identify the putative PbTx binding site in the diatoms. We identified Na+/Ca2+ VCG homologs from the transcriptomes and genomes of 12 diatoms, including three transcripts from O. sinensis and aligned them with site-5 of Na+ VGCs, previously identified as the PbTx binding site in animals. Results Up to 1 µM PbTx had no effect on diatom resting membrane potential or membrane excitability. The kinetics of fast inward Na+/Ca2+ currents that underlie diatom action potentials were also unaffected. However, the peak inward current was inhibited by 33%, delayed outward current was inhibited by 25%, and reversal potential of the currents shifted positive, indicating a change in permeability of the underlying channels. Sequence analysis showed a lack of conservation of the PbTx binding site in diatom VGC homologs, many of which share molecular features more similar to single-domain bacterial Na+/Ca2+ VGCs than the 4-domain eukaryote channels. Discussion Although membrane excitability and the kinetics of action potential currents were unaffected, the permeation of the channels underlying the diatom action potential was significantly altered in the presence of PbTx-3. However, at environmentally relevant concentrations the effects of PbTx- on diatom voltage activated currents and interference of cell signaling through this pathway may be limited. The relative insensitivity of phytoplankton VGCs may be due to divergence of site-5 (the putative PbTx binding site), and in some cases, such as O. sinensis, resistance to toxin effects may be because of evolutionary loss of the 4-domain eukaryote channel, while retaining a single domain bacterial-like VGC that can substitute in the generation of fast action potentials.

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Wilson, William H., Glen A. Tarran, Declan Schroeder, Michael Cox, Joanne Oke i Gillian Malin. "Isolation of viruses responsible for the demise of an Emiliania huxleyi bloom in the English Channel". Journal of the Marine Biological Association of the United Kingdom 82, nr 3 (czerwiec 2002): 369–77. http://dx.doi.org/10.1017/s002531540200560x.

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This study used analytical flow cytometry (AFC) to monitor the abundance of phytoplankton, coccoliths, bacteria and viruses in a transect that crossed a high reflectance area in the western English Channel. The high reflectance area, observed by satellite, was caused by the demise of an Emiliania huxleyi bloom. Water samples were collected from depth profiles at four stations, one station outside and three stations inside the high reflectance area. Plots of transect data revealed very obvious differences between Station 1, outside, and Stations 2–4, inside the high reflectance area. Inside, concentrations of viruses were higher; E. huxleyi cells were lower; coccoliths were higher; bacteria were higher and virus:bacteria ratio was lower than at Station 1, outside the high reflectance area. This data can simply be interpreted as virus-induced lysis of E. huxleyi cells in the bloom causing large concentrations of coccoliths to detach, resulting in the high reflectance observed by satellite imagery. This interpretation was supported by the isolation of two viruses, EhV84 and EhV86, from the high reflectance area that lysed cultures of E. huxleyi host strain CCMP1516. Basic characterization revealed that they were lytic viruses approximately 170 nm–190 nm in diameter with an icosahedral symmetry. Taken together, transect and isolation data suggest that viruses were the major contributor to the demise of the E. huxleyi population in the high reflectance area. Close coupling between microalgae, bacteria and viruses contributed to a large organic carbon input. Consequent cycling influenced the succession of an E. huxleyi-dominated population to a more characteristic mixed summer phytoplankton community.

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Shi, Ruisheng, Yang Zhang, Lina Lan, Fei Li i Junliang Chen. "Summary Instance: Scalable Event Priority Determination Engine for Large-Scale Distributed Event-Based System". International Journal of Distributed Sensor Networks 2015 (2015): 1–14. http://dx.doi.org/10.1155/2015/390329.

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Data prioritization problem is paramount for distributed publish/subscribe infrastructure to the timely delivery of real-time events since a large number of low priority events may clog the channel thereby causing high priority events to get delayed. The challenge raised for the event-based middleware in large-scale distributed system such as vehicular ad hoc networks is that event priority determination engine must be efficient and scalable in terms of priority rule size and event throughputs. This paper proposes an innovative approach based on Bloom filter and event discretization. A Bloom filter data structure is used to store the rule instances and their priorities. The complex rule evaluation is reduced to set membership testing as queries on Bloom filters. The time complexity of data prioritization is constant and independent of the number of priority rules. As event discretization signatures can be cached, this approach is cache friendly in nature. The previous computation results can be cached in overlay network nodes and reused to improve the system throughputs and determination time. We have evaluated our proposed approach and the results show a significant performance improvement.

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Zhou, Yan, Bin Zhou i Ying Ying Gai. "Ulva prolifera Monitoring Study in the Yellow Sea from Multi-Temporal Remote Sensing Images". Applied Mechanics and Materials 675-677 (październik 2014): 1201–6. http://dx.doi.org/10.4028/www.scientific.net/amm.675-677.1201.

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Multi-temporal Moderate resolution Imaging Spectroradiometer (MODIS) remote sensing images were used to monitor the massive blooms of floating green tide algae Ulva prolifera in the midwest of Yellow Sea (YS). In addition, from the marine environment elements of sea surface temperature (SST) and sea surface wind field, the growth and drift characteristic of U. Prolifera were studied based on MODIS thermal infrared channel SST data and Windsat wind field data. In May 2014, U. Prolifera accumulation areas were first found in central YS north of Subei Bank. With summer arrival, seawater temperature of ocean surface gradually increased in YS, It provided a more suitable environment for the growth of U. Prolifera. Due to the prevailing northerly winds in central and western YS, U. Prolifera advected to the coastal waters of Shandong Peninsula, and spread to the northeastward. In late June, it had a massive bloom and reached the maximum coverage in the northern YS. The U. Prolifera drift characteristic was confirmed by the analysis on SST and sea surface wind field, and the result shows that under the environment of suitable sea surface temperature, the driving force of the prevailing sea surface wind field might be the main reason of YS U. Prolifera bloom occurrence.

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Dudeck, Tim, Norbert Rohlf, Christian Möllmann i Marc Hufnagl. "Winter zooplankton dynamics in the English Channel and southern North Sea: trends and drivers from 1991 to 2013". Journal of Plankton Research 43, nr 2 (23.02.2021): 244–56. http://dx.doi.org/10.1093/plankt/fbab011.

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Abstract Winter has long been regarded as a period of minor importance in marine zooplankton ecology with static, low concentrations and growth rates of organisms. Yet, there is growing evidence that winter conditions influence spring bloom strength. With rising water temperatures, growing importance of fish larvae survival during winter and the lack of data to parameterize ecosystem models for this period, research focus shifted on winter zooplankton ecology. To enable looking into past changes in winter zooplankton ecology, we established a new winter zooplankton time series based on samples collected in the eastern English Channel and southern North Sea by the International Herring Larvae Survey since 1988. Four areas of the study region were identified containing different congregations of zooplankton. Overall, zooplankton size decreased while total zooplankton abundance increased, reaching its maximum in 2011. Zooplankton abundance dynamics were mainly related to temperature, chlorophyll a concentration and North Atlantic Oscillation index. Depth and Atlantic water inflow strongly influenced zooplankton size. Increased chlorophyll a concentration and high abundances of small copepods indicated bottom-up controlled secondary production since 2010 and a possible winter bloom in 2011. Based on the analysed parameters, no relation between herring larvae abundance and zooplankton or environmental drivers was determined.

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Cui, Hanlin, Shuguo Chen, Lianbo Hu, Junwei Wang, Haobin Cai, Chaofei Ma, Jianqiang Liu i Bin Zou. "HY1C/D-CZI Noctiluca scintillans Bloom Recognition Network Based on Hybrid Convolution and Self-Attention". Remote Sensing 15, nr 7 (24.03.2023): 1757. http://dx.doi.org/10.3390/rs15071757.

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Accurate Noctiluca scintillans bloom (NSB) recognition from space is of great significance for marine ecological monitoring and underwater target detection. However, most existing NSB recognition models require expert visual interpretation or manual adjustment of model thresholds, which limits model application in operational NSB monitoring. To address these problems, we developed a Noctiluca scintillans Bloom Recognition Network (NSBRNet) incorporating an Inception Conv Block (ICB) and a Swin Attention Block (SAB) based on the latest deep learning technology, where ICB uses convolution to extract channel and local detail features, and SAB uses self-attention to extract global spatial features. The model was applied to Coastal Zone Imager (CZI) data onboard Chinese ocean color satellites (HY1C/D). The results show that NSBRNet can automatically identify NSB using CZI data. Compared with other common semantic segmentation models, NSBRNet showed better performance with a precision of 92.22%, recall of 88.20%, F1-score of 90.10%, and IOU of 82.18%.

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28

Baker, Peter D. "Role of akinetes in the development of cyanobacterial populations in the lower Murray River, Australia". Marine and Freshwater Research 50, nr 3 (1999): 265. http://dx.doi.org/10.1071/mf98090.

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Planktonic populations and benthic resting stages (akinetes) of the common bloom-forming cyanobacteria Anabaena circinalis Rabenhorst and Anabaena flos-aquae f. flos-aquae (Lyngb.) Komárek were monitored in the Murray River near Nildottie and in adjacent floodplain wetlands (lagoons) from 1995 to 1997, to determine the extent of sporulation and the contribution of recruitment from the sediments to seasonal development of blooms. Physical and chemical characteristics of the water in the river and the lagoons were examined in relation to the succession of key life-cycle stages and growth. The warm, shallow lagoons supported considerably higher populations of Anabaena in the summer than did the river, with correspondingly higher incidence of sporulation. Viable akinetes were abundant in the sediments of both the river channel and the lagoons, providing a potentially significant inoculum for cyanobacterial growth. The apparent germination of akinetes early in summer and immediately following sporulation in mid summer indicated a strategy for both initiation and maintenance of populations. A. circinalis also persisted as a planktonic population throughout winter. Germination is considered more likely to occur in the shallow lagoons than in the main channel, principally because of frequent resuspension of sediments containing resting stages to the euphotic zone or because of direct penetration of light to the sediments.

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29

Anderson, CR, MA Brzezinski, L. Washburn i R. Kudela. "Circulation and environmental conditions during a toxigenic Pseudo-nitzschia australis bloom in the Santa Barbara Channel, California". Marine Ecology Progress Series 327 (7.12.2006): 119–33. http://dx.doi.org/10.3354/meps327119.

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30

Seuront, Laurent, Dorothée Vincent i James G. Mitchell. "Biologically induced modification of seawater viscosity in the Eastern English Channel during a Phaeocystis globosa spring bloom". Journal of Marine Systems 61, nr 3-4 (lipiec 2006): 118–33. http://dx.doi.org/10.1016/j.jmarsys.2005.04.010.

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Poulton, A. J., M. C. Stinchcombe, E. P. Achterberg, D. C. E. Bakker, C. Dumousseaud, H. E. Lawson, G. A. Lee, S. Richier, D. J. Suggett i J. R. Young. "Coccolithophores on the north-west European shelf: calcification rates and environmental controls". Biogeosciences Discussions 11, nr 2 (18.02.2014): 2685–733. http://dx.doi.org/10.5194/bgd-11-2685-2014.

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Abstract. Coccolithophores are a key functional group in terms of the pelagic production of calcium carbonate (calcite), although their contribution to shelf-sea biogeochemistry, and how this relates to environmental conditions, is poorly constrained. Measurements of calcite production (CP) and coccolithophore abundance were made on the north-west European shelf to examine trends in coccolithophore calcification along natural gradients of carbonate chemistry, macronutrient availability and plankton composition. Similar measurements were also made in three bioassay experiments where nutrient (nitrate, phosphate) and pCO2 levels were manipulated. Nanoflagellates (< 10 μm) dominated chlorophyll biomass and primary production (PP) at all but one sampling site, with CP ranging from 0.6–9.6 mmol C m−2d−1. Highest CP and coccolithophore cell abundance occurred in a diatom bloom in fully mixed waters off Helgoland, rather than in two distinct coccolithophore blooms in the central North Sea and Western English Channel. Estimates of coccolithophore contributions to total PP and nanoplankton PP were generally < 5%, apart from in a coccolithophore bloom at the Western English Channel Observatory (E1) where coccolithophores contributed up to 11% and at Helgoland where they contributed ~23% to nanoplankton PP. Variability in CP was influenced by cell numbers, species composition and cell-normalised calcification rates under both in situ conditions and in the experimental bioassays. Water column structure and light availability had a strong influence on cellular calcification, whereas nitrate (N) to phosphate (P) ratios influenced bulk CP. Coccolithophore communities in the northern North Sea and over the Norwegian Trench showed responses to N and P addition whereas oceanic communities in the Bay of Biscay showed no response. Sharp decreases in pH and a rough halving of calcite saturation states in the bioassay experiments led to decreased CP in the Bay of Biscay and Northern North Sea, but not over the Norwegian Trench. These variable relationships to nutrient availability and changes in carbonate chemistry highlight the complex response of coccolithophore physiology to growth environment.

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Hennessy, Georgia, Cassanda Uthoff, Sema Abbas, Stefano C. Quaradeghini, Emma Stokes, Dave Goulson i Francis L. W. Ratnieks. "Phenology of the specialist bee Colletes hederae and its dependence on Hedera helix L. in comparison to a generalist, Apis mellifera". Arthropod-Plant Interactions 15, nr 2 (22.02.2021): 183–95. http://dx.doi.org/10.1007/s11829-021-09807-7.

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AbstractColletes hederae,the ivy bee, (Hymenoptera: Colletidae) has undergone large range expansions in Europe in recent years, including colonising Britain in 2001 with its original distribution limited to Western mainland Europe and the Channel Islands. It is thought to specialise onHedera helixL. (Apiales: Ariliaceae), common ivy. However, some research has questioned this dependence. This study quantifies the foraging ecology ofC. hederaeto determine its relationship with ivy in Sussex. We quantified the phenology of ivy bloom,C. hederaeactivity and flower visitation, and pollen collection of females through pollen analysis. We also gathered equivalent data onApis melliferaboth as a comparison and to assess alternative pollen sources. The phenology of femaleC. hederaeactivity was highly correlated with and phonologically contained within the ivy bloom period. Pollen analysis fromC. hederaeidentified ivy pollen was 98.5% of samples, significantly more than forA. mellifera(90%). Two other plant species were identified and more common inC. hederaesamples when ivy bloom was not at its peak. Surveys of ivy flowers surrounding the aggregations found thatC. hederaewere the most common insect (26%) foraging on ivy.AlthoughC. hederaecan forage on other species, ivy was found to be an important floral resource. The results also suggest the potential for competition withA. mellifera, the only other bee present in more than small numbers onH. helixflowers, as althoughA. melliferais a generalist, in autumn it mainly forages on ivy.

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De Madariaga, I., i E. Fernandez. "Photosynthetic carbon metabolism of size-fractionated phytoplankton during an experimental bloom in marine microcosms". Journal of the Marine Biological Association of the United Kingdom 70, nr 3 (sierpień 1990): 531–43. http://dx.doi.org/10.1017/s0025315400036560.

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Water samples, taken from station El in the English Channel, were incubated in 12–1 bottles and monitored for nine days. The distribution pattern of photosynthetically incorporated 14C was followed in three different size-fractions (0·2–2 μm, 2–10 μm and >10 μm) during the development of a bloom.A rapid increase in chlorophyll was observed just after enclosure, the highest values being reached by day 5, when a mixed community of diatoms and small flagellates formed the bulk of phytoplankton biomass. As the bloom developed, nutrients were depleted and, consequently, a decay of the phytoplankton populations occurred. Growth rates, estimated as chlorophyll-specific production rate, were higher for the largest size-fraction (0·53 d−1) than for the intermediate and smallest ones (0·32 d−1 for both).Throughout the bloom, the proportions of 14C incorporated into protein and low molecular weight metabolites (LMWM) were small, whereas the synthesis of storage products appeared to be enhanced. Carbon fixed into protein was higher during the exponential growth phase in all size-fractions, and incorporation into LMWM increased sharply when the bloom declined. Storage product synthesis varied between size-fractions.A close relationship was observed between growth rates, estimated as chlorophyll-specific production rate, and the protein/metabolite synthesis ratio (r2=0·90; n=24). These results suggest that, within the range of environmental variation we studied, this ratio would be a good estimator of growth rate for field studies.

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34

Lamy, D., L. F. Artigas, C. Jauzein, F. Lizon i V. Cornille. "Coastal bacterial viability and production in the eastern English Channel: A case study during a Phaeocystis globosa bloom". Journal of Sea Research 56, nr 3 (październik 2006): 227–38. http://dx.doi.org/10.1016/j.seares.2006.04.003.

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Loveday, Benjamin Roger, i Timothy Smyth. "A 40-year global data set of visible-channel remote-sensing reflectances and coccolithophore bloom occurrence derived from the Advanced Very High Resolution Radiometer catalogue". Earth System Science Data 10, nr 4 (15.11.2018): 2043–54. http://dx.doi.org/10.5194/essd-10-2043-2018.

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Abstract. A consistently calibrated 40-year-long data set of visible-channel remote-sensing reflectance has been derived from the Advanced Very High Resolution Radiometer (AVHRR) sensor global time series. The data set uses as its source the Pathfinder Atmospheres – Extended (PATMOS-x) v5.3 Climate Data Record for top-of-atmosphere (TOA) visible-channel reflectances. This paper describes the theoretical basis for the atmospheric correction procedure and its subsequent implementation, including the necessary ancillary data files used and quality flags applied, in order to determine remote-sensing reflectance. The resulting data set is produced at daily, and archived at monthly, resolution, on a 0.1∘×0.1∘ grid at https://doi.org/10.1594/PANGAEA.892175. The primary aim of deriving this data set is to highlight regions of the global ocean affected by highly reflective blooms of the coccolithophorid Emiliania huxleyi (where lith concentration >2–5×104 mL−1) over the past 40 years.

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36

Lin, Yi, Zhanglin Ye, Yugan Zhang i Jie Yu. "SPECTRAL FEATURE ANALYSIS FOR QUANTITATIVE ESTIMATION OF CYANOBACTERIA CHLOROPHYLL-A". ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLI-B7 (20.06.2016): 91–98. http://dx.doi.org/10.5194/isprs-archives-xli-b7-91-2016.

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In recent years, lake eutrophication caused a large of Cyanobacteria bloom which not only brought serious ecological disaster but also restricted the sustainable development of regional economy in our country. Chlorophyll-a is a very important environmental factor to monitor water quality, especially for lake eutrophication. Remote sensed technique has been widely utilized in estimating the concentration of chlorophyll-a by different kind of vegetation indices and monitoring its distribution in lakes, rivers or along coastline. For each vegetation index, its quantitative estimation accuracy for different satellite data might change since there might be a discrepancy of spectral resolution and channel center between different satellites. The purpose this paper is to analyze the spectral feature of chlorophyll-a with hyperspectral data (totally 651 bands) and use the result to choose the optimal band combination for different satellites. The analysis method developed here in this study could be useful to recognize and monitor cyanobacteria bloom automatically and accrately. In our experiment, the reflectance (from 350nm to 1000nm) of wild cyanobacteria in different consistency (from 0 to 1362.11ug/L) and the corresponding chlorophyll-a concentration were measured simultaneously. Two kinds of hyperspectral vegetation indices were applied in this study: simple ratio (SR) and narrow band normalized difference vegetation index (NDVI), both of which consists of any two bands in the entire 651 narrow bands. Then multivariate statistical analysis was used to construct the linear, power and exponential models. After analyzing the correlation between chlorophyll-a and single band reflectance, SR, NDVI respetively, the optimal spectral index for quantitative estimation of cyanobacteria chlorophyll-a, as well corresponding central wavelength and band width were extracted. Results show that: Under the condition of water disturbance, SR and NDVI are both suitable for quantitative estimation of chlorophyll-a, and more effective than the traditional single band model; the best regression models for SR, NDVI with chlorophyll-a are linear and power, respectively. Under the condition without water disturbance, the single band model works the best. For the SR index, there are two optimal band combinations, which is comprised of infrared (700nm-900nm) and blue-green range (450nm-550nm), infrared and red range (600nm-650nm) respectively, with band width between 45nm to 125nm. For NDVI, the optimal band combination includes the range from 750nm to 900nm and 700nm to 750nm, with band width less than 30nm. For single band model, band center located between 733nm-935nm, and its width mustn’t exceed the interval where band center located in. This study proved , as for SR or NDVI, the centers and widths are crucial factors for quantitative estimating chlorophyll-a. As for remote sensor, proper spectrum channel could not only improve the accuracy of recognizing cyanobacteria bloom, but reduce the redundancy of hyperspectral data. Those results will provide better reference for designing the suitable spectrum channel of customized sensors for cyanobacteria bloom monitoring at a low altitude. In other words, this study is also the basic research for developing the real-time remote sensing monitoring system with high time and high spatial resolution.

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37

Bautista, B., R. P. Harris, P. R. G. Tranter i D. Harbour. "In situ copepod feeding and grazing rates during a spring bloom dominated by Phaeocystis sp. in the English Channel". Journal of Plankton Research 14, nr 5 (1992): 691–703. http://dx.doi.org/10.1093/plankt/14.5.691.

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Spilmont, Nicolas, Lionel Denis, Luis Felipe Artigas, Frédéric Caloin, Lucie Courcot, Anne Créach, Nicolas Desroy i in. "Impact of the Phaeocystis globosa spring bloom on the intertidal benthic compartment in the eastern English Channel: A synthesis". Marine Pollution Bulletin 58, nr 1 (styczeń 2009): 55–63. http://dx.doi.org/10.1016/j.marpolbul.2008.09.007.

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39

Seymour, J. R., L. Seuront, M. J. Doubell i J. G. Mitchell. "Mesoscale and microscale spatial variability of bacteria and viruses during a Phaeocystis globosa bloom in the Eastern English Channel". Estuarine, Coastal and Shelf Science 80, nr 4 (grudzień 2008): 589–97. http://dx.doi.org/10.1016/j.ecss.2008.09.011.

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40

Wilson, William H., Declan C. Schroeder, Jenna Ho i Martin Canty. "Phylogenetic analysis of PgV-102P, a new virus from the English Channel that infects Phaeocystis globosa". Journal of the Marine Biological Association of the United Kingdom 86, nr 3 (10.04.2006): 485–90. http://dx.doi.org/10.1017/s0025315406013385.

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A new virus that infects the harmful algal bloom-forming microalga Phaeocystis globosa was isolated from surface water in the English Channel off the coast of Plymouth, UK, in May 2001. Phylogenetic analysis of the DNA polymerase gene revealed the virus isolate, designated PgV-102P, belongs to the family Phycodnaviridae, a group of large double-stranded DNA viruses known to infect algae. Basic characterization of PgV-102P revealed it was a lytic virus with a relatively slow culture lysis period of 10-days. The genome size (176 kbp) and capsid diameter (98 nm) of PgV-102P fall at the bottom end of the range expected for phycodnaviruses. Interestingly, PgV-102P did not cluster with other P. globosa viruses; instead, it was more closely related to other prymnesioviruses that infect the marine prymnesiophyte Chrysochromulina brevifilum. We discuss the effectiveness of DNA polymerase as a diagnostic marker. Although it is ideal for determining what family or even genus an algal virus belongs to, it is clear that the DNA polymerase gene does not have sufficient resolution when looking for relationships within algal virus genera.

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41

Talbot, Elizabeth, Jorn Bruggeman, Chris Hauton i Stephen Widdicombe. "Uncovering the environmental drivers of short-term temporal dynamics in an epibenthic community from the Western English Channel". Journal of the Marine Biological Association of the United Kingdom 99, nr 7 (5.08.2019): 1467–79. http://dx.doi.org/10.1017/s0025315419000663.

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AbstractBenthic communities, critical to the health and function of marine ecosystems, are under increasing pressure from anthropogenic impacts such as pollution, eutrophication and climate change. In order to refine predictions of likely future changes in benthic communities resulting from these impacts, we must first better constrain their responses to natural seasonality in environmental conditions. Epibenthic time series data (July 2008–May 2014) have been collected from Station L4, situated 7.25 nautical miles south of Plymouth in the Western English Channel. These data were analysed to establish patterns in community abundance, wet biomass and composition, and to link any observed patterns to environmental variables. A clear response to the input of organic material from phytoplankton blooms was detected, with sediment surface living deposit feeders showing an immediate increase in abundance, while predators and scavengers responded later, with an increase in biomass. We suggest that this response is a result of two factors. The low organic content of the L4 sediment results in food limitation of the community, and the mild winter/early spring bottom water temperatures allow the benthos to take immediate advantage of bloom sedimentation. An inter-annual change in community composition was also detected, as the community shifted from one dominated by the anomuran Anapagurus laevis to one dominated by the gastropod Turitella communis. This appeared to be related to a period of high larval recruitment for T. communis in 2013/2014, suggesting that changes in the recruitment success of one species can affect the structure of an entire community.

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42

Lamy, D., I. Obernosterer, M. Laghdass, F. Artigas, E. Breton, JD Grattepanche, E. Lecuyer, N. Degros, P. Lebaron i U. Christaki. "Temporal changes of major bacterial groups and bacterial heterotrophic activity during a Phaeocystis globosa bloom in the eastern English Channel". Aquatic Microbial Ecology 58 (8.12.2009): 95–107. http://dx.doi.org/10.3354/ame01359.

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43

Lin, Yi, Zhanglin Ye, Yugan Zhang i Jie Yu. "SPECTRAL FEATURE ANALYSIS FOR QUANTITATIVE ESTIMATION OF CYANOBACTERIA CHLOROPHYLL-A". ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLI-B7 (20.06.2016): 91–98. http://dx.doi.org/10.5194/isprsarchives-xli-b7-91-2016.

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In recent years, lake eutrophication caused a large of Cyanobacteria bloom which not only brought serious ecological disaster but also restricted the sustainable development of regional economy in our country. Chlorophyll-a is a very important environmental factor to monitor water quality, especially for lake eutrophication. Remote sensed technique has been widely utilized in estimating the concentration of chlorophyll-a by different kind of vegetation indices and monitoring its distribution in lakes, rivers or along coastline. For each vegetation index, its quantitative estimation accuracy for different satellite data might change since there might be a discrepancy of spectral resolution and channel center between different satellites. The purpose this paper is to analyze the spectral feature of chlorophyll-a with hyperspectral data (totally 651 bands) and use the result to choose the optimal band combination for different satellites. The analysis method developed here in this study could be useful to recognize and monitor cyanobacteria bloom automatically and accrately. In our experiment, the reflectance (from 350nm to 1000nm) of wild cyanobacteria in different consistency (from 0 to 1362.11ug/L) and the corresponding chlorophyll-a concentration were measured simultaneously. Two kinds of hyperspectral vegetation indices were applied in this study: simple ratio (SR) and narrow band normalized difference vegetation index (NDVI), both of which consists of any two bands in the entire 651 narrow bands. Then multivariate statistical analysis was used to construct the linear, power and exponential models. After analyzing the correlation between chlorophyll-a and single band reflectance, SR, NDVI respetively, the optimal spectral index for quantitative estimation of cyanobacteria chlorophyll-a, as well corresponding central wavelength and band width were extracted. Results show that: Under the condition of water disturbance, SR and NDVI are both suitable for quantitative estimation of chlorophyll-a, and more effective than the traditional single band model; the best regression models for SR, NDVI with chlorophyll-a are linear and power, respectively. Under the condition without water disturbance, the single band model works the best. For the SR index, there are two optimal band combinations, which is comprised of infrared (700nm-900nm) and blue-green range (450nm-550nm), infrared and red range (600nm-650nm) respectively, with band width between 45nm to 125nm. For NDVI, the optimal band combination includes the range from 750nm to 900nm and 700nm to 750nm, with band width less than 30nm. For single band model, band center located between 733nm-935nm, and its width mustn’t exceed the interval where band center located in. This study proved , as for SR or NDVI, the centers and widths are crucial factors for quantitative estimating chlorophyll-a. As for remote sensor, proper spectrum channel could not only improve the accuracy of recognizing cyanobacteria bloom, but reduce the redundancy of hyperspectral data. Those results will provide better reference for designing the suitable spectrum channel of customized sensors for cyanobacteria bloom monitoring at a low altitude. In other words, this study is also the basic research for developing the real-time remote sensing monitoring system with high time and high spatial resolution.

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44

Serre-Fredj, Léon, Franck Jacqueline, Maxime Navon, Guillaume Izabel, Léo Chasselin, Orianne Jolly, Michel Repecaud i Pascal Claquin. "Coupling high frequency monitoring and bioassay experiments to investigate a harmful algal bloom in the Bay of Seine (French-English Channel)". Marine Pollution Bulletin 168 (lipiec 2021): 112387. http://dx.doi.org/10.1016/j.marpolbul.2021.112387.

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45

Hartman, S. E., M. C. Hartman, D. J. Hydes, D. Smythe-Wright, F. Gohin i P. Lazure. "The role of hydrographic parameters, measured from a ship of opportunity, in bloom formation of Karenia mikimotoi in the English Channel". Journal of Marine Systems 140 (grudzień 2014): 39–49. http://dx.doi.org/10.1016/j.jmarsys.2014.07.001.

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46

Teel, Elizabeth N., Xiao Liu, Bridget N. Seegers, Matthew A. Ragan, William Z. Haskell, Burton H. Jones i Naomi M. Levine. "Contextualizing time-series data: quantification of short-term regional variability in the San Pedro Channel using high-resolution in situ glider data". Biogeosciences 15, nr 20 (19.10.2018): 6151–65. http://dx.doi.org/10.5194/bg-15-6151-2018.

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Abstract. Oceanic time series have been instrumental in providing an understanding of biological, physical, and chemical dynamics in the oceans and how these processes change over time. However, the extrapolation of these results to larger oceanographic regions requires an understanding and characterization of local versus regional drivers of variability. Here we use high-frequency spatial and temporal glider data to quantify variability at the coastal San Pedro Ocean Time-series (SPOT) site in the San Pedro Channel (SPC) and provide insight into the underlying oceanographic dynamics for the site. The dataset could be described by a combination of four water column profile types that typified active upwelling, a surface bloom, warm-stratified low-nutrient conditions, and a subsurface chlorophyll maximum. On weekly timescales, the SPOT station was on average representative of 64 % of profiles taken within the SPC. In general, shifts in water column profile characteristics at SPOT were also observed across the entire channel. On average, waters across the SPC were most similar to offshore profiles, suggesting that SPOT time series data would be more impacted by regional changes in circulation than local coastal events. These results indicate that high-resolution in situ glider deployments can be used to quantify major modes of variability and provide context for interpreting time series data, allowing for broader application of these datasets and greater integration into modeling efforts.

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Karasiewicz, Stéphane, i Alain Lefebvre. "Environmental Impact on Harmful Species Pseudo-nitzschia spp. and Phaeocystis globosa Phenology and Niche". Journal of Marine Science and Engineering 10, nr 2 (27.01.2022): 174. http://dx.doi.org/10.3390/jmse10020174.

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Global environmental change modifies the phytoplankton community, which leads to variations in their phenology and potentially causes a temporal mismatch between primary producers and consumers. In parallel, phytoplankton community change can favor the appearance of harmful species, which makes the understanding of the mechanisms involved in structuring phytoplankton ecological niches paramount for preventing future risk. In this study, we aimed to assess for the first time the relationship between environmental conditions, phenology and niche ecology of harmful species Phaeocystis globosa and the complex Pseudo-nitzschia along the French coast of the eastern English Channel. A new method of bloom detection within a time-series was developed, which allowed the characterization of 363 blooms by 22 phenological variables over 11 stations from 1998 to 2019. The pairwise quantification of asymmetric dependencies between the phenological variables revealed the implication of different mechanisms, common and distinct between the taxa studied. A PERMANOVA helped to reveal the importance of seasonal change in the environmental and community variables. The Outlying Mean and the Within Outlying Mean indexes allowed us to position the harmful taxa niche among the rest of community and quantify how their respective phenology impacted the dynamic of their subniches. We also discussed the possible hypothesis involved and the perspective of predictive models.

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48

Zamon, JE. "Tidal changes in copepod abundance and maintenance of a summer Coscinodiscus bloom in the southern San Juan Channel, San Juan Islands, USA". Marine Ecology Progress Series 226 (2002): 193–210. http://dx.doi.org/10.3354/meps226193.

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Keys, Matthew, Gavin Tilstone, Helen S. Findlay, Claire E. Widdicombe i Tracy Lawson. "Effects of elevated CO2 on phytoplankton community biomass and species composition during a spring Phaeocystis spp. bloom in the western English Channel". Harmful Algae 67 (lipiec 2017): 92–106. http://dx.doi.org/10.1016/j.hal.2017.06.005.

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Green, E. P., R. P. Harris i A. Duncan. "The seasonal abundance of the copepodite stages of Calanus helgolandicus and Pseudocalanus elongatus off Plymouth". Journal of the Marine Biological Association of the United Kingdom 73, nr 1 (luty 1993): 109–22. http://dx.doi.org/10.1017/s0025315400032677.

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The relative abundance of the six copepodite stages (CI-CVI) of Calanus helgolandicus Claus (Copepoda: Calanoida) and Pseudocalanus elongatus Boeck (Copepoda: Calanoida) was recorded at a station in the English Channel throughout 1989. There was a pronounced seasonal variation in the abundance of the early stages. Increased recruitment from the nauplii corresponded in both species to rising primary production early in the year, producing small CI abundance peaks in March. The major period of naupliar development occurred after the April/May spring bloom. During seasonal peaks the CI and CII stages typically formed 40% of the copepodites of these species but were scarce at other times. The body carbon weight of Calanus and Pseudocalanus CIs decreased by 38% and 21% respectively from May to August, indicating an increase in food limitation for the nauplii. Summer was passed predominantly in the CIV and CV stage at low abundances.

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