Indian satellite IRS-P4 (OCEANSAT). Monitoring algal blooms in the Arabian Sea

Digital Repository Service at National Institute of Oceanography (India)

Matondkar, S.G.P.; Bhat, S.R.; Dwivedi, R.M.; Nayak, S.R.

monotis, Prorocentrum lima on the macroalgae of artificial and natural reefs in the Northern Tyrrhenian Sea • Italy Ostreopsis ovata, Coolia monotis, Prorocentrum lima, Prorocentrum sp., Amphidinium sp. have been detected on the Tuscany coast, Tyrrhenian... Sea, on macroalgae on the artificial reefs of Marina di Massa and Versilia, and on the natural reefs of Livorno. The same dinoflagellates have been found on the islands of the Tuscany archipelago: Elba, Giannutri, Giglio [1, 2]. During these blooms...

Salmon mortalities associated with a bloom of Alexandrium ...

African Journals Online (AJOL)

Blue mussels Mytilus edulis analysed from areas affected by the bloom reached levels of 18 000ìg STX equivalents 100g–1 of tissue. As a result of the salmon mortalities, a project was initiated to establish a monitoring approach for harmful algal blooms to provide an early warning of potential events and to act as a tool for ...

Phytoplankton blooms in estuarine and coastal waters: Seasonal patterns and key species

Science.gov (United States)

Carstensen, Jacob; Klais, Riina; Cloern, James E.

2015-01-01

Phytoplankton blooms are dynamic phenomena of great importance to the functioning of estuarine and coastal ecosystems. We analysed a unique (large) collection of phytoplankton monitoring data covering 86 coastal sites distributed over eight regions in North America and Europe, with the aim of investigating common patterns in the seasonal timing and species composition of the blooms. The spring bloom was the most common seasonal pattern across all regions, typically occurring early (February–March) at lower latitudes and later (April–May) at higher latitudes. Bloom frequency, defined as the probability of unusually high biomass, ranged from 5 to 35% between sites and followed no consistent patterns across gradients of latitude, temperature, salinity, water depth, stratification, tidal amplitude or nutrient concentrations. Blooms were mostly dominated by a single species, typically diatoms (58% of the blooms) and dinoflagellates (19%). Diatom-dominated spring blooms were a common feature in most systems, although dinoflagellate spring blooms were also observed in the Baltic Sea. Blooms dominated by chlorophytes and cyanobacteria were only common in low salinity waters and occurred mostly at higher temperatures. Key bloom species across the eight regions included the diatoms Cerataulina pelagica and Dactyliosolen fragilissimus and dinoflagellates Heterocapsa triquetra and Prorocentrum cordatum. Other frequent bloom-forming taxa were diatom genera Chaetoceros, Coscinodiscus, Skeletonema, and Thalassiosira. Our meta-analysis shows that these 86 estuarine-coastal sites function as diatom-producing systems, the timing of that production varies widely, and that bloom frequency is not associated with environmental factors measured in monitoring programs. We end with a perspective on the limitations of conclusions derived from meta-analyses of phytoplankton time series, and the grand challenges remaining to understand the wide range of bloom patterns and

The Cyanobacteria Assessment Network - Recent Success in Harmful Algal Bloom Detection

Science.gov (United States)

Cyanobacteria blooms, which can become harmful algal blooms (HABs), are a huge environmental problem across the United States. They are capable of producing dangerous toxins that threaten the health of humans and animals, quality of drinking water supplies, and the ecosystem in w...

Analysis of algal bloom risk with uncertainties in lakes by integrating self-organizing map and fuzzy information theory

Energy Technology Data Exchange (ETDEWEB)

Chen, Qiuwen, E-mail: qchen@rcees.ac.cn [RCEES, Chinese Academy of Sciences, Shuangqinglu 18, Beijing 10085 (China); China Three Gorges University, Daxuelu 8, Yichang 443002 (China); CEER, Nanjing Hydraulics Research Institute, Guangzhoulu 223, Nanjing 210029 (China); Rui, Han; Li, Weifeng; Zhang, Yanhui [RCEES, Chinese Academy of Sciences, Shuangqinglu 18, Beijing 10085 (China)

2014-06-01

Algal blooms are a serious problem in waters, which damage aquatic ecosystems and threaten drinking water safety. However, the outbreak mechanism of algal blooms is very complex with great uncertainty, especially for large water bodies where environmental conditions have obvious variation in both space and time. This study developed an innovative method which integrated a self-organizing map (SOM) and fuzzy information diffusion theory to comprehensively analyze algal bloom risks with uncertainties. The Lake Taihu was taken as study case and the long-term (2004–2010) on-site monitoring data were used. The results showed that algal blooms in Taihu Lake were classified into four categories and exhibited obvious spatial–temporal patterns. The lake was mainly characterized by moderate bloom but had high uncertainty, whereas severe blooms with low uncertainty were observed in the northwest part of the lake. The study gives insight on the spatial–temporal dynamics of algal blooms, and should help government and decision-makers outline policies and practices on bloom monitoring and prevention. The developed method provides a promising approach to estimate algal bloom risks under uncertainties. - Highlights: • An innovative method is developed to analyze algal bloom risks with uncertainties. • The algal blooms in Taihu Lake showed obvious spatial and temporal patterns. • The lake is mainly characterized as moderate bloom but with high uncertainty. • Severe bloom with low uncertainty appeared occasionally in the northwest part. • The results provide important information to bloom monitoring and management.

Harmful algal blooms of the Southern Benguela current: A review ...

African Journals Online (AJOL)

Harmful algal blooms of the Southern Benguela current: A review and appraisal of monitoring from 1989 to 1997. ... The Benguela upwelling system is subjected to blooms of harmful and toxic algae, the incidence and consequences of which are documented here. Red tides are common and usually attributed to members of ...

Under Sea Ice phytoplankton bloom detection and contamination in Antarctica

Science.gov (United States)

Zeng, C.; Zeng, T.; Xu, H.

2017-12-01

Previous researches reported compelling sea ice phytoplankton bloom in Arctic, while seldom reports studied about Antarctic. Here, lab experiment showed sea ice increased the visible light albedo of the water leaving radiance. Even a new formed sea ice of 10cm thickness increased water leaving radiance up to 4 times of its original bare water. Given that phytoplankton preferred growing and accumulating under the sea ice with thickness of 10cm-1m, our results showed that the changing rate of OC4 estimated [Chl-a] varied from 0.01-0.5mg/m3 to 0.2-0.3mg/m3, if the water covered by 10cm sea ice. Going further, varying thickness of sea ice modulated the changing rate of estimating [Chl-a] non-linearly, thus current routine OC4 model cannot estimate under sea ice [Chl-a] appropriately. Besides, marginal sea ice zone has a large amount of mixture regions containing sea ice, water and snow, where is favorable for phytoplankton. We applied 6S model to estimate the sea ice/snow contamination on sub-pixel water leaving radiance of 4.25km spatial resolution ocean color products. Results showed that sea ice/snow scale effectiveness overestimated [Chl-a] concentration based on routine band ratio OC4 model, which contamination increased with the rising fraction of sea ice/snow within one pixel. Finally, we analyzed the under sea ice bloom in Antarctica based on the [Chl-a] concentration trends during 21 days after sea ice retreating. Regardless of those overestimation caused by sea ice/snow sub scale contamination, we still did not see significant under sea ice blooms in Antarctica in 2012-2017 compared with Arctic. This research found that Southern Ocean is not favorable for under sea ice blooms and the phytoplankton bloom preferred to occur in at least 3 weeks after sea ice retreating.

Monitoring tools and early warning system for harmful cyanobacterial blooms: Río Uruguay and Río de la Plata

Directory of Open Access Journals (Sweden)

Carla Kruk

2015-12-01

Full Text Available Potentially hazardous cyanobacterial blooming constitutes one of the most widespread problems experienced by aquatic systems worldwide. However, there are not any monitoring methods sensitive enough to be directly applicable to predict and manage blooming events. In order to fulfill this goal, both ecological and genetic concepts were combined to generate cyanobacteria monitoring tools. Two approaches were used: grouping organisms into functional groups and utilizing molecular analysis (real time quantitative PCR as indicators of the presence of genes that encode the expression of cyanotoxins (mcy. Six bi-monthly sampling campaigns were performed to evaluate the suitability of these tools (2013-2014 at six locations composed of two sites each one, ranging downstream from Salto Grande, at the River Uruguay, to Punta del Este, at the Estuary River Plate. A remarkable gradient was observed in the meteorological, physical and chemical variables, as well as higher abundances in planktonic organisms both in Salto Grande and in Punta del Este. The most abundant population of toxic species in the whole gradient were found in Salto, and in particular those belonging to the Microcystis aeruginosa complex (MAC. The most relevant environmental variables to determine the gradient and the variation in biological variables were: salinity, temperature, wind and turbidity. The results of the new indicators (presence of MAC in the plankton net and mcy genes were in agreement with the traditional ones (v.g. chlorophyll-a demonstrating being much more sensitive in cases of the most severe blooming events than in the low abundance situations. The conjunction of results was applied to the construction of a monitoring and early warning system protocol.

UV-Visible Spectroscopic Method and Models for Assessment and Monitoring of Harmful Algal Blooms

Science.gov (United States)

Mitchell, B. Greg

2000-01-01

The development of an enhanced predictive and early warning capability for the occurrence and impact of harmful algal blooms (HABs) would be of great benefit to coastal communities. A critical issue for early detection and monitoring of HABs is the need to detect harmful algal species within a mixed-species phytoplankton assemblage. Possession of UV-absorbing compounds called mycosporine-like amino acids (MAAs) may be one factor that allows HAB species to out-compete their phytoplankton neighbors. Possession of MAAs, which we believe can be inferred from strong UV-absorption signals in phytoplankton absorption coefficients, can be used as a flag for potential HAB outbreak. The goal of this project was to develop a solar simulating UV-visible incubator to grow HAB dinoflagellates, to begin MAA analysis of samples collected on global cruises, and to carry out initial experiments on HAB dinoflagellate species in pure culture. Our scientific objectives are to quantify MAA production and spectral induction mechanisms in HAB species, to characterize spectral absorption of MAAs, and to define the ecological benefit of MAAs (i.e. photoprotection). Data collected on cruises to the global oceans will be used to parameterize phytoplankton absorption in the UV region, and this parameterization could be incorporated into existing models of seawater optical properties in the UV spectral region. Data collected in this project were used for graduate fellowship applications by Elizabeth Frame. She has been awarded an EPA STAR fellowship to continue the work initiated by this project.

Effects of fertilizers used in agricultural fields on algal blooms

Science.gov (United States)

Chakraborty, Subhendu; Tiwari, P. K.; Sasmal, S. K.; Misra, A. K.; Chattopadhyay, Joydev

2017-06-01

The increasing occurrence of algal blooms and their negative ecological impacts have led to intensified monitoring activities. This needs the proper identification of the most responsible factor/factors for the bloom formation. However, in natural systems, algal blooms result from a combination of factors and from observation it is difficult to identify the most important one. In the present paper, using a mathematical model we compare the effects of three human induced factors (fertilizer input in agricultural field, eutrophication due to other sources than fertilizers, and overfishing) on the bloom dynamics and DO level. By applying a sophisticated sensitivity analysis technique, we found that the increasing use of fertilizers in agricultural field causes more rapid algal growth and decreases DO level much faster than eutrophication from other sources and overfishing. We also look at the mechanisms how fertilizer input rate affects the algal bloom dynamics and DO level. The model can be helpful for the policy makers in determining the influential factors responsible for the bloom formation.

Cyanobacteria, Toxins and Indicators: Field Monitoring,Treatment Facility Monitoring and Treatment Studies

Science.gov (United States)

This presentation is a compilation of harmful algal bloom (HAB) related field monitoring data from the 2015 bloom season, treatment plant monitoring data from the 2013 and 2014 bloom seasons, and bench-scale treatment study data from 2015.

Monitoring of ocean surface algal blooms in coastal and oceanic waters around India.

Digital Repository Service at National Institute of Oceanography (India)

Tholkapiyan, M.; Shanmugam, P.; Suresh, T.

of the MODIS-Aqua-derived OSABI (ocean surface algal bloom index) and its seasonal composite images report new information and comprehensive pictures of these blooms and their evolution stages in a wide variety of events occurred at different times of the years...

Predicting potentially toxigenic Pseudo-nitzschia blooms in the Chesapeake Bay

Science.gov (United States)

Anderson, Clarissa R.; Sapiano, Mathew R. P.; Prasad, M. Bala Krishna; Long, Wen; Tango, Peter J.; Brown, Christopher W.; Murtugudde, Raghu

2010-11-01

Harmful algal blooms are now recognized as a significant threat to the Chesapeake Bay as they can severely compromise the economic viability of important recreational and commercial fisheries in the largest estuary of the United States. This study describes the development of empirical models for the potentially domoic acid-producing Pseudo-nitzschia species complex present in the Bay, developed from a 22-year time series of cell abundance and concurrent measurements of hydrographic and chemical properties. Using a logistic Generalized Linear Model (GLM) approach, model parameters and performance were compared over a range of Pseudo-nitzschia bloom thresholds relevant to toxin production by different species. Small-threshold blooms (≥10 cells mL -1) are explained by time of year, location, and variability in surface values of phosphate, temperature, nitrate plus nitrite, and freshwater discharge. Medium- (100 cells mL -1) to large- threshold (1000 cells mL -1) blooms are further explained by salinity, silicic acid, dissolved organic carbon, and light attenuation (Secchi) depth. These predictors are similar to other models for Pseudo-nitzschia blooms on the west coast, suggesting commonalities across ecosystems. Hindcasts of bloom probabilities at a 19% bloom prediction point yield a Heidke Skill Score of ~53%, a Probability of Detection ˜ 75%, a False Alarm Ratio of ˜ 52%, and a Probability of False Detection ˜9%. The implication of possible future changes in Baywide nutrient stoichiometry on Pseudo-nitzschia blooms is discussed.

sxtA-based quantitative molecular assay to identify saxitoxin-producing harmful algal blooms in marine waters.

Science.gov (United States)

Murray, Shauna A; Wiese, Maria; Stüken, Anke; Brett, Steve; Kellmann, Ralf; Hallegraeff, Gustaaf; Neilan, Brett A

2011-10-01

The recent identification of genes involved in the production of the potent neurotoxin and keystone metabolite saxitoxin (STX) in marine eukaryotic phytoplankton has allowed us for the first time to develop molecular genetic methods to investigate the chemical ecology of harmful algal blooms in situ. We present a novel method for detecting and quantifying the potential for STX production in marine environmental samples. Our assay detects a domain of the gene sxtA that encodes a unique enzyme putatively involved in the sxt pathway in marine dinoflagellates, sxtA4. A product of the correct size was recovered from nine strains of four species of STX-producing Alexandrium and Gymnodinium catenatum and was not detected in the non-STX-producing Alexandrium species, other dinoflagellate cultures, or an environmental sample that did not contain known STX-producing species. However, sxtA4 was also detected in the non-STX-producing strain of Alexandrium tamarense, Tasmanian ribotype. We investigated the copy number of sxtA4 in three strains of Alexandrium catenella and found it to be relatively constant among strains. Using our novel method, we detected and quantified sxtA4 in three environmental blooms of Alexandrium catenella that led to STX uptake in oysters. We conclude that this method shows promise as an accurate, fast, and cost-effective means of quantifying the potential for STX production in marine samples and will be useful for biological oceanographic research and harmful algal bloom monitoring.

Dinoflagellate blooms in upwelling systems: Seeding, variability, and contrasts with diatom bloom behaviour

Science.gov (United States)

Smayda, T. J.; Trainer, V. L.

2010-04-01

The influence of diatom bloom behaviour, dinoflagellate life cycles, propagule type and upwelling bloom cycles on the seeding of dinoflagellate blooms in eastern boundary current upwelling systems is evaluated. Winter-spring diatom bloom behaviour is contrasted with upwelling bloom behaviour because their phenology impacts dinoflagellate blooms. The winter-spring diatom bloom is usually sustained, whereas the classical upwelling diatom bloom occurs as a series of separate, recurrent mini-blooms intercalated by upwelling-relaxation periods, during which dinoflagellates often bloom. Four sequential wind-regulated phases characterize upwelling cycles, with each phase having different effects on diatom and dinoflagellate bloom behaviour: bloom “spin up”, bloom maximum, bloom “spin down”, and upwelling relaxation. The spin up - bloom maximum is the period of heightened diatom growth; the spin down - upwelling-relaxation phases are the periods when dinoflagellates often bloom. The duration, intensity and ratio of the upwelling and relaxation periods making up upwelling cycles determine the potential for dinoflagellate blooms to develop within a given upwelling cycle and prior to the subsequent “spin up” of upwelling that favours diatom blooms. Upwelling diatoms and meroplanktonic dinoflagellates have three types of propagules available to seed blooms: vegetative cells, resting cells and resting cysts. However, most upwelling dinoflagellates are holoplanktonic, which indicates that the capacity to form resting cysts is not an absolute requirement for growth and survival in upwelling systems. The long-term (decadal) gaps in bloom behaviour of Gymnodinium catenatum and Lingulodinium polyedrum, and the unpredictable bloom behaviour of dinoflagellates generally, are examined from the perspective of seeding strategies. Mismatches between observed and expected in situ bloom behaviour and resting cyst dynamics are common among upwelling dinoflagellates. This

Testing a Microarray to Detect and Monitor Toxic Microalgae in Arcachon Bay in France

Directory of Open Access Journals (Sweden)

Linda K. Medlin

2013-03-01

Full Text Available Harmful algal blooms (HABs occur worldwide, causing health problems and economic damages to fisheries and tourism. Monitoring agencies are therefore essential, yet monitoring is based only on time-consuming light microscopy, a level at which a correct identification can be limited by insufficient morphological characters. The project MIDTAL (Microarray Detection of Toxic Algae—an FP7-funded EU project—used rRNA genes (SSU and LSU as a target on microarrays to identify toxic species. Furthermore, toxins were detected with a newly developed multiplex optical Surface Plasmon Resonance biosensor (Multi SPR and compared with an enzyme-linked immunosorbent assay (ELISA. In this study, we demonstrate the latest generation of MIDTAL microarrays (version 3 and show the correlation between cell counts, detected toxin and microarray signals from field samples taken in Arcachon Bay in France in 2011. The MIDTAL microarray always detected more potentially toxic species than those detected by microscopic counts. The toxin detection was even more sensitive than both methods. Because of the universal nature of both toxin and species microarrays, they can be used to detect invasive species. Nevertheless, the MIDTAL microarray is not completely universal: first, because not all toxic species are on the chip, and second, because invasive species, such as Ostreopsis, already influence European coasts.

An algorithm for detecting Trichodesmium surface blooms in the South Western Tropical Pacific

Directory of Open Access Journals (Sweden)

Y. Dandonneau

2011-12-01

Full Text Available Trichodesmium, a major colonial cyanobacterial nitrogen fixer, forms large blooms in NO3-depleted tropical oceans and enhances CO2 sequestration by the ocean due to its ability to fix dissolved dinitrogen. Thus, its importance in C and N cycles requires better estimates of its distribution at basin to global scales. However, existing algorithms to detect them from satellite have not yet been successful in the South Western Tropical Pacific (SP. Here, a novel algorithm (TRICHOdesmium SATellite based on radiance anomaly spectra (RAS observed in SeaWiFS imagery, is used to detect Trichodesmium during the austral summertime in the SP (5° S–25° S 160° E–170° W. Selected pixels are characterized by a restricted range of parameters quantifying RAS spectra (e.g. slope, intercept, curvature. The fraction of valid (non-cloudy pixels identified as Trichodesmium surface blooms in the region is low (between 0.01 and 0.2 %, but is about 100 times higher than deduced from previous algorithms. At daily scales in the SP, this fraction represents a total ocean surface area varying from 16 to 48 km2 in Winter and from 200 to 1000 km2 in Summer (and at monthly scale, from 500 to 1000 km2 in Winter and from 3100 to 10 890 km2 in Summer with a maximum of 26 432 km2 in January 1999. The daily distribution of Trichodesmium surface accumulations in the SP detected by TRICHOSAT is presented for the period 1998–2010 which demonstrates that the number of selected pixels peaks in November–February each year, consistent with field observations. This approach was validated with in situ observations of Trichodesmium surface accumulations in the Melanesian archipelago around New Caledonia, Vanuatu and Fiji Islands for the same period.

Analysis of algal bloom risk with uncertainties in lakes by integrating self-organizing map and fuzzy information theory.

Science.gov (United States)

Chen, Qiuwen; Rui, Han; Li, Weifeng; Zhang, Yanhui

2014-06-01

Algal blooms are a serious problem in waters, which damage aquatic ecosystems and threaten drinking water safety. However, the outbreak mechanism of algal blooms is very complex with great uncertainty, especially for large water bodies where environmental conditions have obvious variation in both space and time. This study developed an innovative method which integrated a self-organizing map (SOM) and fuzzy information diffusion theory to comprehensively analyze algal bloom risks with uncertainties. The Lake Taihu was taken as study case and the long-term (2004-2010) on-site monitoring data were used. The results showed that algal blooms in Taihu Lake were classified into four categories and exhibited obvious spatial-temporal patterns. The lake was mainly characterized by moderate bloom but had high uncertainty, whereas severe blooms with low uncertainty were observed in the northwest part of the lake. The study gives insight on the spatial-temporal dynamics of algal blooms, and should help government and decision-makers outline policies and practices on bloom monitoring and prevention. The developed method provides a promising approach to estimate algal bloom risks under uncertainties. Copyright © 2014 Elsevier B.V. All rights reserved.

Satellite monitoring of cyanobacterial harmful algal bloom ...

Science.gov (United States)

Cyanobacterial harmful algal blooms (cyanoHABs) cause extensive problems in lakes worldwide, including human and ecological health risks, anoxia and fish kills, and taste and odor problems. CyanoHABs are a particular concern because of their dense biomass and the risk of exposure to toxins in both recreational waters and drinking source waters. Successful cyanoHAB assessment by satellites may provide a first-line of defense indicator for human and ecological health protection. In this study, assessment methods were developed to determine the utility of satellite technology for detecting cyanoHAB occurrence frequency at locations of potential management interest. The European Space Agency's MEdium Resolution Imaging Spectrometer (MERIS) was evaluated to prepare for the equivalent Sentinel-3 Ocean and Land Colour Imager (OLCI) launched in 2016. Based on the 2012 National Lakes Assessment site evaluation guidelines and National Hydrography Dataset, there were 275,897 lakes and reservoirs greater than 1 hectare in the 48 U.S. states. Results from this evaluation show that 5.6 % of waterbodies were resolvable by satellites with 300 m single pixel resolution and 0.7 % of waterbodies were resolvable when a 3x3 pixel array was applied based on minimum Euclidian distance from shore. Satellite data was also spatially joined to US public water surface intake (PWSI) locations, where single pixel resolution resolved 57% of PWSI and a 3x3 pixel array resolved 33% of

sxtA-Based Quantitative Molecular Assay To Identify Saxitoxin-Producing Harmful Algal Blooms in Marine Waters ▿ †

Science.gov (United States)

Murray, Shauna A.; Wiese, Maria; Stüken, Anke; Brett, Steve; Kellmann, Ralf; Hallegraeff, Gustaaf; Neilan, Brett A.

2011-01-01

The recent identification of genes involved in the production of the potent neurotoxin and keystone metabolite saxitoxin (STX) in marine eukaryotic phytoplankton has allowed us for the first time to develop molecular genetic methods to investigate the chemical ecology of harmful algal blooms in situ. We present a novel method for detecting and quantifying the potential for STX production in marine environmental samples. Our assay detects a domain of the gene sxtA that encodes a unique enzyme putatively involved in the sxt pathway in marine dinoflagellates, sxtA4. A product of the correct size was recovered from nine strains of four species of STX-producing Alexandrium and Gymnodinium catenatum and was not detected in the non-STX-producing Alexandrium species, other dinoflagellate cultures, or an environmental sample that did not contain known STX-producing species. However, sxtA4 was also detected in the non-STX-producing strain of Alexandrium tamarense, Tasmanian ribotype. We investigated the copy number of sxtA4 in three strains of Alexandrium catenella and found it to be relatively constant among strains. Using our novel method, we detected and quantified sxtA4 in three environmental blooms of Alexandrium catenella that led to STX uptake in oysters. We conclude that this method shows promise as an accurate, fast, and cost-effective means of quantifying the potential for STX production in marine samples and will be useful for biological oceanographic research and harmful algal bloom monitoring. PMID:21841034

Phytoplankton-Associated Bacterial Community Composition and Succession during Toxic Diatom Bloom and Non-Bloom Events.

Science.gov (United States)

Sison-Mangus, Marilou P; Jiang, Sunny; Kudela, Raphael M; Mehic, Sanjin

2016-01-01

Pseudo-nitzschia blooms often occur in coastal and open ocean environments, sometimes leading to the production of the neurotoxin domoic acid that can cause severe negative impacts to higher trophic levels. Increasing evidence suggests a close relationship between phytoplankton bloom and bacterial assemblages, however, the microbial composition and succession during a bloom process is unknown. Here, we investigate the bacterial assemblages before, during and after toxic and non-toxic Pseudo-nitzschia blooms to determine the patterns of bacterial succession in a natural bloom setting. Opportunistic sampling of bacterial community profiles were determined weekly at Santa Cruz Municipal Wharf by 454 pyrosequencing and analyzed together with domoic acid levels, phytoplankton community and biomass, nutrients and temperature. We asked if the bacterial communities are similar between bloom and non-bloom events and if domoic acid or the presence of toxic algal species acts as a driving force that can significantly structure phytoplankton-associated bacterial communities. We found that bacterial diversity generally increases when Pseudo-nitzschia numbers decline. Furthermore, bacterial diversity is higher when the low-DA producing P. fraudulenta dominates the algal bloom while bacterial diversity is lower when high-DA producing P. australis dominates the algal bloom, suggesting that the presence of algal toxin can structure bacterial community. We also found bloom-related succession patterns among associated bacterial groups; Gamma-proteobacteria, were dominant during low toxic P. fraudulenta blooms comprising mostly of Vibrio spp., which increased in relative abundance (6-65%) as the bloom progresses. On the other hand, Firmicutes bacteria comprising mostly of Planococcus spp. (12-86%) dominate during high toxic P. australis blooms, with the bacterial assemblage showing the same bloom-related successional patterns in three independent bloom events. Other environmental

Phytoplankton-associated bacterial community composition and succession during toxic diatom bloom and non-bloom events

Directory of Open Access Journals (Sweden)

Marilou P. Sison-Mangus

2016-09-01

Full Text Available Pseudo-nitzschia blooms often occur in coastal and open ocean environments, sometimes leading to the production of the neurotoxin domoic acid that can cause severe negative impacts to higher trophic levels. Increasing evidence suggests a close relationship between phytoplankton bloom and bacterial assemblages, however, the microbial composition and succession during a bloom process is unknown. Here, we investigate the bacterial assemblages before, during and after toxic and non-toxic Pseudo-nitzschia blooms to determine the patterns of bacterial succession in a natural bloom setting. Opportunistic sampling of bacterial community profiles were determined weekly at Santa Cruz Municipal Wharf by 454 pyrosequencing and analyzed together with domoic acid levels, phytoplankton community and biomass, nutrients and temperature. We asked if the bacterial communities are similar between bloom and non-bloom events and if domoic acid or the presence of toxic algal species acts as a driving force that can significantly structure phytoplankton-associated bacterial communities. We found that bacterial diversity generally increases when Pseudo-nitzschia numbers decline. Furthermore, bacterial diversity is higher when the low-DA producing P. fraudulenta dominates the algal bloom while bacterial diversity is lower when high-DA producing P. australis dominates the algal bloom, suggesting that the presence of algal toxin can structure bacterial community. We also found bloom-related succession patterns among associated bacterial groups; Gamma-proteobacteria, were dominant during low toxic P. fraudulenta blooms comprising mostly of Vibrio spp., which increased in relative abundance (6%-65% as the bloom progresses. On the other hand, Firmicutes bacteria comprising mostly of Planococcus spp. (12%- 86% dominate during high toxic P. australis blooms, with the bacterial assemblage showing the same bloom-related successional patterns in 3 independent bloom events. Other

Identification of Phytoplankton Blooms under the Index of Inherent Optical Properties (IOP Index in Optically Complex Waters

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Jesús A. Aguilar-Maldonado

2018-01-01

Full Text Available Phytoplankton blooms are sporadic events in time and are isolated in space. This complex phenomenon is produced by a variety of both natural and anthropogenic causes. Early detection of this phenomenon, as well as the classification of a water body under conditions of bloom or non-bloom, remains an unresolved problem. This research proposes the use of Inherent Optical Properties (IOPs in optically complex waters to detect the bloom or non-bloom state of the phytoplankton community. An IOP index is calculated from the absorption coefficients of the colored dissolved organic matter (CDOM, the phytoplankton (phy and the detritus (d, using the wavelength (λ 443 nm. The effectiveness of this index is tested in five bloom events in different places and with different characteristics from Mexican seas: 1. Dzilam (Caribbean Sea, Atlantic Ocean, a diatom bloom (Rhizosolenia hebetata; 2. Holbox (Caribbean Sea, Atlantic Ocean, a mixed bloom of dinoflagellates (Scrippsiella sp. and diatoms (Chaetoceros sp.; 3. Campeche Bay in the Gulf of Mexico (Atlantic Ocean, a bloom of dinoflagellates (Karenia brevis; 4. Upper Gulf of California (UGC (Pacific Ocean, a diatom bloom (Coscinodiscus and Pseudo-nitzschia and 5. Todos Santos Bay, Ensenada (Pacific Ocean, a dinoflagellate bloom (Lingulodinium polyedrum. The diversity of sites show that the IOP index is a suitable method to determine the phytoplankton bloom conditions.

A new bio-optical algorithm for the remote sensing of algal blooms in complex ocean waters

Science.gov (United States)

Shanmugam, Palanisamy

2011-04-01

A new bio-optical algorithm has been developed to provide accurate assessments of chlorophyll a (Chl a) concentration for detection and mapping of algal blooms from satellite data in optically complex waters, where the presence of suspended sediments and dissolved substances can interfere with phytoplankton signal and thus confound conventional band ratio algorithms. A global data set of concurrent measurements of pigment concentration and radiometric reflectance was compiled and used to develop this algorithm that uses the normalized water-leaving radiance ratios along with an algal bloom index (ABI) between three visible bands to determine Chl a concentrations. The algorithm is derived using Sea-viewing Wide Field-of-view Sensor bands, and it is subsequently tuned to be applicable to Moderate Resolution Imaging Spectroradiometer (MODIS)/Aqua data. When compared with large in situ data sets and satellite matchups in a variety of coastal and ocean waters the present algorithm makes good retrievals of the Chl a concentration and shows statistically significant improvement over current global algorithms (e.g., OC3 and OC4v4). An examination of the performance of these algorithms on several MODIS/Aqua images in complex waters of the Arabian Sea and west Florida shelf shows that the new algorithm provides a better means for detecting and differentiating algal blooms from other turbid features, whereas the OC3 algorithm has significant errors although yielding relatively consistent results in clear waters. These findings imply that, provided that an accurate atmospheric correction scheme is available to deal with complex waters, the current MODIS/Aqua, MERIS and OCM data could be extensively used for quantitative and operational monitoring of algal blooms in various regional and global waters.

A novel earth observation based ecological indicator for cyanobacterial blooms

Science.gov (United States)

Anttila, Saku; Fleming-Lehtinen, Vivi; Attila, Jenni; Junttila, Sofia; Alasalmi, Hanna; Hällfors, Heidi; Kervinen, Mikko; Koponen, Sampsa

2018-02-01

Cyanobacteria form spectacular mass occurrences almost annually in the Baltic Sea. These harmful algal blooms are the most visible consequences of marine eutrophication, driven by a surplus of nutrients from anthropogenic sources and internal processes of the ecosystem. We present a novel Cyanobacterial Bloom Indicator (CyaBI) targeted for the ecosystem assessment of eutrophication in marine areas. The method measures the current cyanobacterial bloom situation (an average condition of recent 5 years) and compares this to the estimated target level for 'good environmental status' (GES). The current status is derived with an index combining indicative bloom event variables. As such we used seasonal information from the duration, volume and severity of algal blooms derived from earth observation (EO) data. The target level for GES was set by using a remote sensing based data set named Fraction with Cyanobacterial Accumulations (FCA; Kahru & Elmgren, 2014) covering years 1979-2014. Here a shift-detection algorithm for time series was applied to detect time-periods in the FCA data where the level of blooms remained low several consecutive years. The average conditions from these time periods were transformed into respective CyaBI target values to represent target level for GES. The indicator is shown to pass the three critical factors set for marine indicator development, namely it measures the current status accurately, the target setting can be scientifically proven and it can be connected to the ecosystem management goal. An advantage of the CyaBI method is that it's not restricted to the data used in the development work, but can be complemented, or fully applied, by using different types of data sources providing information on cyanobacterial accumulations.

Cyanobacteria and Algae Blooms: Review of Health and Environmental Data from the Harmful Algal Bloom-Related Illness Surveillance System (HABISS) 2007–2011

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Backer, Lorraine C.; Manassaram-Baptiste, Deana; LePrell, Rebecca; Bolton, Birgit

2015-01-01

Algae and cyanobacteria are present in all aquatic environments. We do not have a good sense of the extent of human and animal exposures to cyanobacteria or their toxins, nor do we understand the public health impacts from acute exposures associated with recreational activities or chronic exposures associated with drinking water. We describe the Harmful Algal Bloom-related Illness Surveillance System (HABISS) and summarize the collected reports describing bloom events and associated adverse human and animal health events. For the period of 2007–2011, Departments of Health and/or Environment from 11 states funded by the National Center for Environmental Health (NCEH), Centers for Disease Control and Prevention contributed reports for 4534 events. For 2007, states contributed 173 reports from historical data. The states participating in the HABISS program built response capacity through targeted public outreach and prevention activities, including supporting routine cyanobacteria monitoring for public recreation waters. During 2007–2010, states used monitoring data to support196 public health advisories or beach closures. The information recorded in HABISS and the application of these data to develop a wide range of public health prevention and response activities indicate that cyanobacteria and algae blooms are an environmental public health issue that needs continuing attention. PMID:25826054

Large-sized seaweed monitoring based on MODIS

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Ma, Long; Li, Ying; Lan, Guo-xin; Li, Chuan-long

2009-10-01

In recent years, large-sized seaweed, such as ulva lactuca, blooms frequently in coastal water in China, which threatens marine eco-environment. In order to take effective measures, it is important to make operational surveillance. A case of large-sized seaweed blooming (i.e. enteromorpha), occurred in June, 2008, in the sea near Qingdao city, is studied. Seaweed blooming is dynamically monitored using Moderate Resolution Imaging Spectroradiometer (MODIS). After analyzing imaging spectral characteristics of enteromorpha, MODIS band 1 and 2 are used to create a band ratio algorithm for detecting and mapping large-sized seaweed blooming. In addition, chlorophyll-α concentration is inversed based on an empirical model developed using MODIS. Chlorophyll-α concentration maps are derived using multitemporal MODIS data, and chlorophyll-α concentration change is analyzed. Results show that the presented methods are useful to get the dynamic distribution and the growth of large-sized seaweed, and can support contingency planning.

Harmful algal bloom smart device application: using image analysis and machine learning techniques for classification of harmful algal blooms

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Northern Kentucky University and the U.S. EPA Office of Research Development in Cincinnati Agency are collaborating to develop a harmful algal bloom detection algorithm that estimates the presence of cyanobacteria in freshwater systems by image analysis. Green and blue-green alg...

Harmful algal blooms

Digital Repository Service at National Institute of Oceanography (India)

Bhat, S.R.; PrabhaDevi; DeSouza, L.; Verlecar, X.N.; Naik, C.G.

as harmful algal bloom. Bloom formation is a natural process and it enhances biological productivity, but turns worrisome when caused by toxic species, leading to massive fish mortalities and hazards to human health. Incidences of'red tide' are increasing...

Recreational Exposure to Low Concentrations of Microcystins During an Algal Bloom in a Small Lake

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Yung-Sung Cheng

2008-06-01

Full Text Available We measured microcystins in blood from people at risk for swallowing water or inhaling spray while swimming, water skiing, jet skiing, or boating during an algal bloom. We monitored water samples from a small lake as a Microcystis aeruginosa bloom developed. We recruited 97 people planning recreational activities in that lake and seven others who volunteered to recreate in a nearby bloom-free lake. We conducted our field study within a week of finding a 10-μg/L microcystin concentration. We analyzed water, air, and human blood samples for water quality, potential human pathogens, algal taxonomy, and microcystin concentrations. We interviewed study participants for demographic and current health symptom information. Water samples were assayed for potential respiratory viruses (adenoviruses and enteroviruses, but none were detected. We did find low concentrations of Escherichia coli, indicating fecal contamination. We found low levels of microcystins (2 μg/L to 5 μg/L in the water and (<0.1 ng/m3 in the aerosol samples. Blood levels of microcystins for all participants were below the limit of detection (0.147μg/L. Given this low exposure level, study participants reported no symptom increases following recreational exposure to microcystins. This is the first study to report that water-based recreational activities can expose people to very low concentrations of aerosol-borne microcystins; we recently conducted another field study to assess exposures to higher concentrations of these algal toxins.

Using high-throughput DNA sequencing, genetic fingerprinting, and quantitative PCR as tools for monitoring bloom-forming and toxigenic cyanobacteria in Upper Klamath Lake, Oregon, 2013 and 2014

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Caldwell Eldridge, Sara L.; Driscoll, Conner; Dreher, Theo W.

2017-06-05

Monitoring the community structure and metabolic activities of cyanobacterial blooms in Upper Klamath Lake, Oregon, is critical to lake management because these blooms degrade water quality and produce toxic microcystins that are harmful to humans, domestic animals, and wildlife. Genetic tools, such as DNA fingerprinting by terminal restriction fragment length polymorphism (T-RFLP) analysis, high-throughput DNA sequencing (HTS), and real-time, quantitative polymerase chain reaction (qPCR), provide more sensitive and rapid assessments of bloom ecology than traditional techniques. The objectives of this study were (1) to characterize the microbial community at one site in Upper Klamath Lake and determine changes in the cyanobacterial community through time using T-RFLP and HTS in comparison with traditional light microscopy; (2) to determine relative abundances and changes in abundance over time of toxigenic Microcystis using qPCR; and (3) to determine relative abundances and changes in abundance over time of Aphanizomenon, Microcystis, and total cyanobacteria using qPCR. T-RFLP analysis of total cyanobacteria showed a dominance of only one or two distinct genotypes in samples from 2013, but results of HTS in 2013 and 2014 showed more variations in the bloom cycle that fit with the previous understanding of bloom dynamics in Upper Klamath Lake and indicated that potentially toxigenic Microcystis was more prevalent in 2014 than in years prior. The qPCR-estimated copy numbers of all target genes were higher in 2014 than in 2013, when microcystin concentrations also were higher. Total Microcystis density was shown with qPCR to be a better predictor of late-season increases in microcystin concentrations than the relative proportions of potentially toxigenic cells. In addition, qPCR targeting Aphanizomenon at one site in Upper Klamath Lake indicated a moderate bloom of this species (corresponding to chlorophyll a concentrations between approximately 75 and 200 micrograms

Effect of Zeolite Treatment on the Blooming Behavior of Paraffin Wax in Natural Rubber Composites

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Bryan B. Pajarito

2016-06-01

Full Text Available The blooming behavior of paraffin wax in natural rubber (NR composites was studied as function of zeolite treatment. Three types of zeolite treatment were treated as factors: acid activation using hydrochloric acid (HCl solution, ion exchange using tetradecyldimethyl amine (TDA chloride salt, and organic modification using glycerol monostearate (GMS. The zeolite was treated according to a 23 full factorial design of experiment. Attenuated total reflectance – Fourier transform infrared (ATR-FTIR spectroscopy was used to characterize the chemical structure of treated zeolite. Treated zeolite was applied as filler to NR composites deliberately compounded with high amount of paraff in wax. The amount of bloomed wax in surface of NR composite sheets was monitored with time at 50oC. Results show the bloom amount to be linear with the square root of time. NR composites reinforced with untreated, acid-activated, and ion-exchanged zeolite fillers indicate reduction in wax blooming as compared to unfilled NR. The bloom rate (slope and initial bloom (y-intercept were determined from the experimental plots. Analysis of variance (ANOVA shows the bloom rate to be signif icantly increased when zeolite fillers are treated with GMS. Meanwhile, initial bloom was significantly enhanced when zeolite fillers are treated with TDA chloride salt and GMS. The significant increase in bloom rate and initial bloom can be attributed to the softening of the NR matrix at high amounts of TDA chloride salt and GMS.

Satellite Remote Sensing and Crowd Sourcing to Monitor and Predict Cyanobacteria Blooms

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Cyanobacterial blooms occur worldwide and are associated with human respiratory irritation, undesirable taste and odor of potable water, increased drinking water treatment costs, loss of revenue from recreational use, and human illness as a result of ingestion or skin exposure du...

Evaluation of Rapid, Early Warning Approaches to Track Shellfish Toxins Associated with Dinophysis and Alexandrium Blooms

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Theresa K. Hattenrath-Lehmann

2018-01-01

Full Text Available Marine biotoxin-contaminated seafood has caused thousands of poisonings worldwide this century. Given these threats, there is an increasing need for improved technologies that can be easily integrated into coastal monitoring programs. This study evaluates approaches for monitoring toxins associated with recurrent toxin-producing Alexandrium and Dinophysis blooms on Long Island, NY, USA, which cause paralytic and diarrhetic shellfish poisoning (PSP and DSP, respectively. Within contrasting locations, the dynamics of pelagic Alexandrium and Dinophysis cell densities, toxins in plankton, and toxins in deployed blue mussels (Mytilus edulis were compared with passive solid-phase adsorption toxin tracking (SPATT samplers filled with two types of resin, HP20 and XAD-2. Multiple species of wild shellfish were also collected during Dinophysis blooms and used to compare toxin content using two different extraction techniques (single dispersive and double exhaustive and two different toxin analysis assays (liquid chromatography/mass spectrometry and the protein phosphatase inhibition assay (PP2A for the measurement of DSP toxins. DSP toxins measured in the HP20 resin were significantly correlated (R2 = 0.7–0.9, p < 0.001 with total DSP toxins in shellfish, but were detected more than three weeks prior to detection in deployed mussels. Both resins adsorbed measurable levels of PSP toxins, but neither quantitatively tracked Alexandrium cell densities, toxicity in plankton or toxins in shellfish. DSP extraction and toxin analysis methods did not differ significantly (p > 0.05, were highly correlated (R2 = 0.98–0.99; p < 0.001 and provided complete recovery of DSP toxins from standard reference materials. Blue mussels (Mytilus edulis and ribbed mussels (Geukensia demissa were found to accumulate DSP toxins above federal and international standards (160 ng g−1 during Dinophysis blooms while Eastern oysters (Crassostrea virginica and soft shell clams (Mya

Toxin composition of the 2016 Microcystis aeruginosa bloom in the St. Lucie Estuary, Florida.

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Oehrle, Stuart; Rodriguez-Matos, Marliette; Cartamil, Michael; Zavala, Cristian; Rein, Kathleen S

2017-11-01

A bloom of the cyanobacteria, Microcystis aeruginosa occurred in the St. Lucie Estuary during the summer of 2016, stimulated by the release of waters from Lake Okeechobee. This cyanobacterium produces the microcystins, a suite of heptapeptide hepatotoxins. The toxin composition of the bloom was analyzed and was compared to an archived bloom sample from 2005. Microcystin-LR was the most abundant toxin with lesser amounts of microcystin variants. Nodularin, cylindrospermopsin and anatoxin-a were not detected. Copyright © 2017 Elsevier Ltd. All rights reserved.

Insights into toxic Prymnesium parvum blooms: the role of sugars and algal viruses.

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Wagstaff, Ben A; Hems, Edward S; Rejzek, Martin; Pratscher, Jennifer; Brooks, Elliot; Kuhaudomlarp, Sakonwan; O'Neill, Ellis C; Donaldson, Matthew I; Lane, Steven; Currie, John; Hindes, Andrew M; Malin, Gill; Murrell, J Colin; Field, Robert A

2018-04-17

Prymnesium parvum is a toxin-producing microalga that causes harmful algal blooms globally, which often result in large-scale fish kills that have severe ecological and economic implications. Although many toxins have previously been isolated from P. parvum , ambiguity still surrounds the responsible ichthyotoxins in P. parvum blooms and the biotic and abiotic factors that promote bloom toxicity. A major fish kill attributed to P. parvum occurred in Spring 2015 on the Norfolk Broads, a low-lying set of channels and lakes (Broads) found on the East of England. Here, we discuss how water samples taken during this bloom have led to diverse scientific advances ranging from toxin analysis to discovery of a new lytic virus of P. parvum , P. parvum DNA virus (PpDNAV-BW1). Taking recent literature into account, we propose key roles for sialic acids in this type of viral infection. Finally, we discuss recent practical detection and management strategies for controlling these devastating blooms. © 2018 The Author(s).

Toxic cyanobacteria blooms in the Lithuanian part of the Curonian Lagoon

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Artūras Razinkovas

2009-06-01

Full Text Available The phenomenon of cyanobacteria (blue-green algae blooms in the Baltic and the surrounding freshwater bodies has been known for several decades. The presence of cyanobacterial toxic metabolites in the Curonian Lagoon has been investigated and demonstrated for the first time in this work (2006-2007. Microcystis aeruginosa was the most common and widely distributed species in the 2006 blooms. Nodularia spumigena was present in the northern part of the Curonian Lagoon, following the intrusion of brackish water from the Baltic Sea; this is the first time that this nodularin-(NOD-producing cyanobacterium has been recorded in the lagoon. With the aid of high-performance liquid chromatography (HPLC, four microcystins (MC-LR, MC-RR, MC-LY, MC-YR and nodularin were detected in 2006. The presence of these cyanobacterial hepatotoxic cyclic peptides was additionally confirmed by enzyme-linked immunosorbent assay (ELISA and protein phosphatase inhibition assay (PP1. Microcystin-LR, the most frequent of them, was present in every sample at quite high concentrations (from <0.1 to 134.2 µg dm-3. In 2007, no cyanobacterial bloom was recorded and cyanotoxins were detected in only 4% of the investigated samples. A comparably high concentration of nodularin was detected in the northern part of the Curonian Lagoon. In one sample dimethylated MC-RR was also detected (concentration 7.5 µg dm-3.

Seasonal cooling and blooming in tropical oceans

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Longhurst, Alan

1993-11-01

The relative importance of tropical pelagic algal blooms in not yet fully appreciated and the way they are induced not well understood. The tropical Atlantic supports pelagic blooms together equivalent to the North Atlantic spring bloom. These blooms are driven by thermocline tilting, curl of wind stress and eddy upwelling as the ocean responds to intensified basin-scale winds in boreal summer. The dimensions of the Pacific Ocean are such that seasonal thermocline tilting does not occur, and nutrient conditions are such that tilting might not induce bloom, in any case. Divergence at the equator is a separate process that strengthens the Atlantic bloom, is more prominent in the eastern Pacific, and in the Indian Ocean induces a bloom only in the western part of the ocean. Where western jet currents are retroflected from the coast off Somalia and Brazil, eddy upwelling induces prominent blooms. In the eastward flow of the northern equatorial countercurrents, positive wind curl stress induces Ekman pumping and the induction of algal blooms aligned with the currents. Some apparent algal bloom, such as that seen frequently in CZCS images westwards from Senegal, must be due to interference from airborne dust.

Applications of MODIS Fluorescence Line Height Measurements to Monitor Water Quality Trends and Algal Bloom Activity in Coastal and Estuarine Waters

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Fischer, A.; Ryan, J. P.; Moreno-Madriñán, M. J.

2012-12-01

Recent advances in satellite and airborne remote sensing, such as improvements in sensor and algorithm calibrations and atmospheric correction procedures have provided for increased coverage of remote-sensing, ocean color products for coastal regions. In particular, for the Moderate Resolution Imaging Spectrometer (MODIS), calibration updates, improved aerosol retrievals, and new aerosol models have led to improved atmospheric correction algorithms for turbid waters and have improved the retrieval of ocean-color. This has opened the way for studying coastal ocean phenomena and processes at finer spatial scales. Human population growth and changes in coastal management practices have brought about significant changes in the concentrations of organic and inorganic, particulate and dissolved substances entering the coastal ocean. There is increasing concern that these inputs have led to declines in water quality and increases in local concentrations of phytoplankton, which could result in harmful algal blooms. In two case studies we present improved and validated MODIS coastal observations of fluorescence line height (FLH) to: (1) assess trends in water quality for Tampa Bay, Florida; and (2) illustrate seasonal and annual variability of algal bloom activity in Monterey Bay, California, as well as document estuarine/riverine plume induced red tide events. In a comprehensive analysis of long term (2003-2011) in situ monitoring data and imagery from Tampa Bay, we assess the validity of the MODIS FLH product against chlorophyll-a and a suite of water quality parameters taken in a variety of conditions throughout this large, optically complex estuarine system. A systematic analysis of sampling sites throughout the bay illustrates that the correlations between FLH and in situ chlorophyll-a are influenced by water quality parameters of total nitrogen, total phosphorous, turbidity and biological oxygen demand. Sites that correlated well with satellite imagery were in depths

The antibiotic resistome of free-living and particle-attached bacteria under a reservoir cyanobacterial bloom.

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Guo, Yunyan; Liu, Min; Liu, Lemian; Liu, Xuan; Chen, Huihuang; Yang, Jun

2018-05-04

In freshwater systems, both antibiotic resistance genes (ARGs) and cyanobacterial blooms attract global public health concern. Cyanobacterial blooms can greatly impact bacterial taxonomic communities, but very little is known about the influence of the blooms on antibiotic resistance functional community. In this study, the ARGs in both free-living (FL) and particle-attached (PA) bacteria under bloom and non-bloom conditions were simultaneously investigated in a subtropical reservoir using high-throughput approaches. In total, 145 ARGs and 9 mobile genetic elements (MGEs) were detected. The most diverse and dominant of which (68.93%) were multidrug resistance genes and efflux pump mechanism. The richness of ARGs in both FL and PA bacteria was significantly lower during the bloom period compared with non-bloom period. The abundance of ARGs in FL bacteria was significantly lower under bloom condition than in the non-bloom period, but the abundance of ARGs in PA bacteria stayed constant. More importantly, the resistant functional community in PA bacteria was more strongly influenced by the cyanobacterial bloom than in the FL bacteria, although >96% ARGs were shared in both FL and PA bacteria or both bloom and non-bloom periods. We also compared the community compositions between taxonomy and function, and found antibiotic resistant communities were highly variable and exhibited lower similarity between bloom and non-bloom periods than seen in the taxonomic composition, with an exception of FL bacteria. Altogether, cyanobacterial blooms appear to have stronger inhibitory effect on ARG abundance in FL bacteria, and stronger influence on antibiotic resistant community composition in PA bacteria. Our results further suggested that both neutral and selective processes interactively affected the ARG composition dynamics of the FL and PA bacteria. However, the antibiotic resistant community of FL bacteria exhibited a higher level of temporal stochasticity following the bloom

Harmful algal blooms and Vibrio spp. association in fishing and marine farming areas of mollusk bivalves in Sechura and Pisco bays, Peru

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Rita Orozco

2017-04-01

Full Text Available Between February 2010 and May 2014, 22 surveys in Pisco and 16 in Sechura were conducted; both are major areas for shellfish production and mariculture in Peru. The incidence of Vibrio in seawater was monitored during algal blooms and in their absence. Environmental parameters such as temperature and nutrients were measured. In Sechura, Pseudo-nitzschia seriata and Protoperidinium depressum caused algal blooms and were dominant throughout the evaluation period. The temperatures in this area ranged from 21.8 to 25.3 °C. In Pisco, the harmful algal bloom-forming Akashiwo sanguinea, Messodinium rubrum, and Prorocentrum minimum and the dinoflagellate Cochlodinium polikrykoides were most prevalent. Harmful algal blooms occurred when temperatures were between 17.1 and 23.3 °C, with phosphates ranging 1.22 - 6.85 µM and nitrates 0.15 - 7.85 µM. In May 2012, the dinoflagellate Alexandrium peruvianum caused an algal bloom, with temperatures ranging 18.0 to 23.2 °C, phosphate values from 0.73 to 11.56 µM, and nitrates from 0.76 to 9.81 µM. Coliforms were low, < 2 - 23 MPN/100 ml, in both bays throughout the study period. Vibrio alginolyticus was the dominant Vibrio spp. predominated in both bays, while V. vulnificus and V. parahaemolyticus were detected in Pisco, where warmer sea temperatures are common and severe infections cases by seafood ingestion has been associated with a pathogen V. parahaemolyticus.

Harmful Algal Blooms of the West Florida Shelf and Campeche Bank: Visualization and Quantification using Remote Sensing Methods

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Soto Ramos, Inia Mariel

Harmful Algal Blooms (HABs) in the Gulf of Mexico (GOM) are natural phenomena that can have negative impacts on marine ecosystems on which human health and the economy of some Gulf States depends. Many of the HABs in the GOM are dominated by the toxic dinoflagellate Karenia brevis. Non-toxic phytoplankton taxa such as Scrippsiella sp. also form intense blooms off the Mexican coast that result in massive fish mortality and economic losses, particularly as they may lead to anoxia. The main objectives of this dissertation were to (1) evaluate and improve the techniques developed for detection of Karenia spp. blooms on the West Florida Shelf (WFS) using satellite remote sensing methods, (2) test the use of these methods for waters in the GOM, and (3) use the output of these techniques to better understand the dynamics and evolution of Karenia spp. blooms in the WFS and off Mexico. The first chapter of this dissertation examines the performance of several Karenia HABs detection techniques using Moderate Resolution Imaging Spectroradiometer (MODIS) satellite images and historical ground truth observations collected on the WFS from August 2002 to December 2011. A total of 2323 in situ samples collected by the Florida Fish and Wildlife Research Institute to test for Karenia spp. matched pixels with valid ocean color satellite observations over this period. This dataset was used to systematically optimize variables and coefficients used in five published HAB detection methods. Each technique was tested using a set of metrics that included the F-Measure (FM). Before optimization, the average FM for all techniques was 0.47. After optimization, the average FM increased to 0.59, and false positives decreased ~50%. The addition of a Fluorescence Line Height (FLH) criterion improved the performance of every method. A new practical method was developed using a combination of FLH and Remote Sensing Reflectance at 555 nm (Rrs555-FLH). The new method resulted in an FM of 0.62 and 3

An overview of cyanobacterial bloom occurrences and research in Africa over the last decade.

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Ndlela, L L; Oberholster, P J; Van Wyk, J H; Cheng, P H

2016-12-01

Cyanobacterial blooms are a current cause for concern globally, with vital water sources experiencing frequent and increasingly toxic blooms in the past decade. These increases are resultant of both anthropogenic and natural factors, with climate change being the central concern. Of the more affected parts of the world, Africa has been considered particularly vulnerable due to its historical predisposition and lag in social economic development. This review collectively assesses the available information on cyanobacterial blooms in Africa as well as any visible trends associated with reported occurrences over the last decade. Of the 54 countries in Africa, only 21 have notable research information in the area of cyanobacterial blooms within the last decade, although there is substantial reason to attribute these blooms as some of the major water quality threats in Africa collectively. The collected information suggests that civil wars, disease outbreaks and inadequate infrastructure are at the core of Africa's delayed advancement. This is even more so in the area of cyanobacteria related research, with 11 out of 21 countries having recorded toxicity and physicochemical parameters related to cyanobacterial blooms. Compared to the rest of the continent, peripheral countries are at the forefront of research related to cyanobacteria, with countries such as Angola having sufficient rainfall, but poor water quality with limited information on bloom occurrences. An assessment of the reported blooms found nitrogen concentrations to be higher in the water column of more toxic blooms, validating recent global studies and indicating that phosphorous is not the only factor to be monitored in bloom mitigation. Blooms occurred at low TN: TP ratios and at temperatures above 12°C. Nitrogen was linked to toxicity and temperature also had a positive effect on bloom occurrence and toxicity. Microcystis was the most ubiquitous of the cyanobacterial strains reported in Africa and the

Great Lake beach-goer behavior during a retrospectively detected bloom of cyanobacteria

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Cyanobacteria blooms pose a potential health risk to beachgoers. We conducted a prospective study of weekend beachgoers at a public Great Lake site during July – September 2003. We recorded each person’s health status and activity during their beach visit. We measured...

Localization and Tracking of Submerged Phytoplankton Bloom Patches by an Autonomous Underwater Vehicle

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Godin, M. A.; Ryan, J. P.; Zhang, Y.; Bellingham, J. G.

2012-12-01

Observing plankton in their drifting frame of reference permits effective studies of marine ecology from the perspective of microscopic life itself. By minimizing variation caused simply by advection, observations in a plankton-tracking frame of reference focus measurement capabilities on the processes that influence the life history of populations. Further, the patchy nature of plankton populations motivates use of sensor data in real-time to resolve patch boundaries and adapt observing resources accordingly. We have developed capabilities for population-centric plankton observation and sampling by autonomous underwater vehicles (AUVs). Our focus has been on phytoplankton populations, both because of their ecological significance - as the core of the oceanic food web and yet potentially harmful under certain bloom conditions, as well as the accessibility of their signal to simple optical sensing. During the first field deployment of these capabilities in 2010, we tracked a phytoplankton patch containing toxigenic diatoms and found that their toxicity correlated with exposure to resuspended sediments. However, this first deployment was labor intensive as the AUV drove in a pre-programmed pattern centered around a patch-marking drifter; it required a boat deployment of the patch-marking drifter and required full-time operators to periodically estimate of the position of the patch with respect to the drifter and adjust the AUV path accordingly. In subsequent field experiments during 2011 and 2012, the Tethys-class long-range AUVs ran fully autonomous patch tracking algorithms which detected phytoplankton patches and continually updated estimates of each patch center by driving adaptive patterns through the patch. Iterations of the algorithm were generated to overcome the challenges of tracking advecting and evolving patches while minimizing human involvement in vehicle control. Such fully autonomous monitoring will be necessary to perform long-term in

A Multiscale Mapping Assessment of Lake Champlain Cyanobacterial Harmful Algal Blooms

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Nathan Torbick

2015-09-01

Full Text Available Lake Champlain has bays undergoing chronic cyanobacterial harmful algal blooms that pose a public health threat. Monitoring and assessment tools need to be developed to support risk decision making and to gain a thorough understanding of bloom scales and intensities. In this research application, Landsat 8 Operational Land Imager (OLI, Rapid Eye, and Proba Compact High Resolution Imaging Spectrometer (CHRIS images were obtained while a corresponding field campaign collected in situ measurements of water quality. Models including empirical band ratio regressions were applied to map chlorophylla and phycocyanin concentrations; all sensors performed well with R2 and root-mean-square error (RMSE ranging from 0.76 to 0.88 and 0.42 to 1.51, respectively. The outcomes showed spatial patterns across the lake with problematic bays having phycocyanin concentrations >25 μg/L. An alert status metric tuned to the current monitoring protocol was generated using modeled water quality to illustrate how the remote sensing tools can inform a public health monitoring system. Among the sensors utilized in this study, Landsat 8 OLI holds the most promise for providing exposure information across a wide area given the resolutions, systematic observation strategy and free cost.

Monitoring of radionuclides in carbon steel blooms produced by EAF process

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Sofilić T.

2011-01-01

Full Text Available Because natural and artificial isotopes in steel might originate from steel scrap or from the residue of the material that was used in the technological process, thus monitoring especially artificial radionuclides 60Co, 137Cs and 192Ir deserve special attention. The analysis by g-spectrometry has been applied to determine the presence of natural isotopes 40K, 226Ra, 232Th and 238U as well as of the artificial isotope 60Co, 137Cs and 192Ir and their activity in the produced steel round blooms in the Steel Mill of CMC Sisak d.o.o. At the same time the content of radionuclides in the other materials (ferroalloys, bauxite, fluorite, lime, coke, graphite electrodes, refractory blocks used in the same steel making process was investigated. The measured values regarding the presence of individual isotopes and their activity in steel were as follows: 40K all values were less than 1.6 Bqkg-1; 232Th all activities values were less than 0.02 Bqkg-1; 226Ra all activities values were less than 0.01 Bqkg-1; 238U all activities values were less than 1.10 Bqkg-1; 60Co all activities values were less than 0.02 Bqkg-1; 192Ir all activities values were less than 0.02 Bqkg-1 and 137Cs all activities values were less than 0.30 Bqkg-1.

Blooming Artifact Reduction in Coronary Artery Calcification by A New De-blooming Algorithm: Initial Study.

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Li, Ping; Xu, Lei; Yang, Lin; Wang, Rui; Hsieh, Jiang; Sun, Zhonghua; Fan, Zhanming; Leipsic, Jonathon A

2018-05-02

The aim of this study was to investigate the use of de-blooming algorithm in coronary CT angiography (CCTA) for optimal evaluation of calcified plaques. Calcified plaques were simulated on a coronary vessel phantom and a cardiac motion phantom. Two convolution kernels, standard (STND) and high-definition standard (HD STND), were used for imaging reconstruction. A dedicated de-blooming algorithm was used for imaging processing. We found a smaller bias towards measurement of stenosis using the de-blooming algorithm (STND: bias 24.6% vs 15.0%, range 10.2% to 39.0% vs 4.0% to 25.9%; HD STND: bias 17.9% vs 11.0%, range 8.9% to 30.6% vs 0.5% to 21.5%). With use of de-blooming algorithm, specificity for diagnosing significant stenosis increased from 45.8% to 75.0% (STND), from 62.5% to 83.3% (HD STND); while positive predictive value (PPV) increased from 69.8% to 83.3% (STND), from 76.9% to 88.2% (HD STND). In the patient group, reduction in calcification volume was 48.1 ± 10.3%, reduction in coronary diameter stenosis over calcified plaque was 52.4 ± 24.2%. Our results suggest that the novel de-blooming algorithm could effectively decrease the blooming artifacts caused by coronary calcified plaques, and consequently improve diagnostic accuracy of CCTA in assessing coronary stenosis.

How many Coccolithovirus genotypes does it take to terminate an Emiliania huxleyi bloom?

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Highfield, Andrea; Evans, Claire; Walne, Anthony; Miller, Peter I; Schroeder, Declan C

2014-10-01

Giant viruses are known to be significant mortality agents of phytoplankton, often being implicated in the terminations of large Emiliania huxleyi blooms. We have previously shown the high temporal variability of E. huxleyi-infecting coccolithoviruses (EhVs) within a Norwegian fjord mesocosm. In the current study we investigated EhV dynamics within a naturally-occurring E. huxleyi bloom in the Western English Channel. Using denaturing gradient gel electrophoresis and marker gene sequencing, we uncovered a spatially highly dynamic Coccolithovirus population that was associated with a genetically stable E. huxleyi population as revealed by the major capsid protein gene (mcp) and coccolith morphology motif (CMM), respectively. Coccolithoviruses within the bloom were found to be variable with depth and unique virus populations were detected at different stations sampled indicating a complex network of EhV-host infections. This ultimately will have significant implications to the internal structure and longevity of ecologically important E. huxleyi blooms. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

Temporal influences on satellite retrieval of cyanobacteria bloom: an examination in Lake Taihu, China

Science.gov (United States)

Zhang, Yue; Liu, Yuanbo; Ruan, Renzong; Zhao, Dongbo

2009-10-01

Satellite imagery provides a cost-effective way to retrieve the cyanbacteria bloom dynamics, which is useful to early warning of the blooms. However, temporal variations in sun-target-satellite geometry and atmosphere may generate inconsistencies in multi-temporal images. To explore to what extent temporal influences could affect the retrieved results, we applied the single band and the band ratio approaches to retrieve cyanobacteria bloom in Lake Taihu of China. We used the Moderate Resolution Imaging Spectroradiometer (MODIS) products in the cases with and without correction for sun-target-satellite geometry and atmospheric effects for the whole year 2006. In addition, we made use of MODIS data including aerosol optical thickness (AOT), solar zenith angle and sensor zenith angle, all of which are indicators of the temporal influences. We then analyzed the relationships of retrieval differences with the three indicators to evaluate the temporal influences quantitatively. Our results showed that both AOT and solar zenith angle had a positive correlation with the retrieval of cyanobacteria bloom. Although it is yet under investigation if this relationship could hold on for other cases, here we emphasized that for reliable monitoring the dynamics of bloom, it should be careful to apply the approaches using satellite data without radiometric correction.

Characterisation of algal organic matter produced by bloom-forming marine and freshwater algae

KAUST Repository

Villacorte, Loreen O.

2015-04-01

Algal blooms can seriously affect the operation of water treatment processes including low pressure (micro- and ultra-filtration) and high pressure (nanofiltration and reverse osmosis) membranes mainly due to accumulation of algal-derived organic matter (AOM). In this study, the different components of AOM extracted from three common species of bloom-forming algae (Alexandrium tamarense, Chaetoceros affinis and Microcystis sp.) were characterised employing various analytical techniques, such as liquid chromatography - organic carbon detection, fluorescence spectroscopy, fourier transform infrared spectroscopy, alcian blue staining and lectin staining coupled with laser scanning microscopy to indentify its composition and force measurement using atomic force microscopy to measure its stickiness. Batch culture monitoring of the three algal species illustrated varying characteristics in terms of growth pattern, cell concentration and AOM release. The AOM produced by the three algal species comprised mainly biopolymers (e.g., polysaccharides and proteins) but some refractory compounds (e.g., humic-like substances) and other low molecular weight acid and neutral compounds were also found. Biopolymers containing fucose and sulphated functional groups were found in all AOM samples while the presence of other functional groups varied between different species. A large majority (>80%) of the acidic polysaccharide components (in terms of transparent exopolymer particles) were found in the colloidal size range (<0.4μm). The relative stickiness of AOM substantially varied between algal species and that the cohesion between AOM-coated surfaces was much stronger than the adhesion of AOM on AOM-free surfaces. Overall, the composition as well as the physico-chemical characteristics (e.g., stickiness) of AOM will likely dictate the severity of fouling in membrane systems during algal blooms.

Spatio-temporal interdependence of bacteria and phytoplankton during a Baltic Sea spring bloom

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Carina eBunse

2016-04-01

Full Text Available In temperate systems, phytoplankton spring blooms deplete inorganic nutrients and are major sources of organic matter for the microbial loop. In response to phytoplankton exudates and environmental factors, heterotrophic microbial communities are highly dynamic and change their abundance and composition both on spatial and temporal scales. Yet, most of our understanding about these processes comes from laboratory model organism studies, mesocosm experiments or single temporal transects. Spatial-temporal studies examining interactions of phytoplankton blooms and bacterioplankton community composition and function, though being highly informative, are scarce. In this study, pelagic microbial community dynamics (bacteria and phytoplankton and environmental variables were monitored during a spring bloom across the Baltic Proper (two cruises between North Germany to Gulf of Finland. To test to what extent bacterioplankton community composition relates to the spring bloom, we used next generation amplicon sequencing of the 16S rRNA gene, phytoplankton diversity analysis based on microscopy counts and population genotyping of the dominating diatom Skeletonema marinoi. Several phytoplankton bloom related and environmental variables were identified to influence bacterial community composition. Members of Bacteroidetes and Alphaproteobacteria dominated the bacterial community composition but the bacterial groups showed no apparent correlation with direct bloom related variables. The less abundant bacterial phyla Actinobacteria, Planctomycetes, and Verrucomicrobia, on the other hand, were strongly associated with phytoplankton biomass, diatom:dinoflagellate ratio and colored dissolved organic matter (cDOM. Many bacterial operational taxonomic units (OTUs showed high niche specificities. For example, particular Bacteroidetes OTUs were associated with two distinct genetic clusters of S. marinoi. Our study revealed the complexity of interactions of bacterial

Wind-driven marine phytoplank blooms: Satellite observation and analysis

Science.gov (United States)

Tang, DanLing

2016-07-01

Algal bloom is defined as a rapid increase or accumulation in biomass in an aquatic system. It not only can increase the primary production but also could result in negative ecological consequence, e.g.,Harmful Algal Blooms (HABs). According to the classic theory for the formation of algal blooms "critical depth" and "eutrophication", oligotrophic sea area is usually difficult to form a large area of algal blooms, and actuallythe traditional observation is only sporadic capture to the existence of algal blooms.Taking full advantage of multiple data of satellite remote sensing , this study introduces "Wind-driven algal blooms in open oceans: observation and mechanisms" It explained except classic coastal Ekman transport, the wind through a variety of mechanisms affecting the formation of algal blooms. Proposed a conceptual model of "Strong wind -upwelling-nutrient-phytoplankton blooms" in Western South China Sea (SCS) to assess role of wind-induced advection transport in phytoplankton bloom formation. It illustrates the nutrient resources that support long-term offshore phytoplankton blooms in the western SCS; (2)Proposal of the theory that "typhoons cause vertical mixing, induce phytoplankton blooms", and quantify their important contribution to marine primary production; Proposal a new ecological index for typhoon. Proposed remote sensing inversion models. (3)Finding of the spatial and temporaldistributions pattern of harmful algal bloom (HAB)and species variations of HAB in the South Yellow Sea and East China Sea, and in the Pearl River estuary, and their oceanic dynamic mechanisms related with monsoon; The project developed new techniques and generated new knowledge, which significantly improved understanding of the formation mechanisms of algal blooms. The proposed "wind-pump" mechanism integrates theoretical system combined "ocean dynamics, development of algal blooms, and impact on primary production", which will benefit fisheries management. These

Recurrent blooms of Heterosigma akashiwo (Raphidophyceae in the Piraquê Channel, Rodrigo de Freitas Lagoon, southeast Brazil

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S Branco

Full Text Available 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.

Peach Flower Monitoring Using Aerial Multispectral Imaging

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Ryan Horton

2017-01-01

Full Text Available One of the tools for optimal crop production is regular monitoring and assessment of crops. During the growing season of fruit trees, the bloom period has increased photosynthetic rates that correlate with the fruiting process. This paper presents the development of an image processing algorithm to detect peach blossoms on trees. Aerial images of peach (Prunus persica trees were acquired from both experimental and commercial peach orchards in the southwestern part of Idaho using an off-the-shelf unmanned aerial system (UAS, equipped with a multispectral camera (near-infrared, green, blue. The image processing algorithm included contrast stretching of the three bands to enhance the image and thresholding segmentation method to detect the peach blossoms. Initial results showed that the image processing algorithm could detect peach blossoms with an average detection rate of 84.3% and demonstrated good potential as a monitoring tool for orchard management.

A New Bloom: Transforming Learning

Science.gov (United States)

Cochran, David; Conklin, Jack

2007-01-01

This article discusses a new design for the classic Bloom's Taxonomy developed by Anderson, L. W. & Krathwohl, D. (2001), which can be used to evaluate learners' technology-enhanced experience in more powerful and critical ways. The New Bloom's Taxonomy incorporates contemporary research on learning and human cognition into its model. The…

Health-Based Cyanotoxin Guideline Values Allow for Cyanotoxin-Based Monitoring and Efficient Public Health Response to Cyanobacterial Blooms

Science.gov (United States)

Farrer, David; Counter, Marina; Hillwig, Rebecca; Cude, Curtis

2015-01-01

Human health risks from cyanobacterial blooms are primarily related to cyanotoxins that some cyanobacteria produce. Not all species of cyanobacteria can produce toxins. Those that do often do not produce toxins at levels harmful to human health. Monitoring programs that use identification of cyanobacteria genus and species and enumeration of cyanobacterial cells as a surrogate for cyanotoxin presence can overestimate risk and lead to unnecessary health advisories. In the absence of federal criteria for cyanotoxins in recreational water, the Oregon Health Authority (OHA) developed guideline values for the four most common cyanotoxins in Oregon’s fresh waters (anatoxin-a, cylindrospermopsin, microcystins, and saxitoxins). OHA developed three guideline values for each of the cyanotoxins found in Oregon. Each of the guideline values is for a specific use of cyanobacteria-affected water: drinking water, human recreational exposure and dog recreational exposure. Having cyanotoxin guidelines allows OHA to promote toxin-based monitoring (TBM) programs, which reduce the number of health advisories and focus advisories on times and places where actual, rather than potential, risks to health exist. TBM allows OHA to more efficiently protect public health while reducing burdens on local economies that depend on water recreation-related tourism. PMID:25664510

Developing Predictive Models for Algal Bloom Occurrence and Identifying Factors Controlling their Occurrence in the Charlotte County and Surroundings

Science.gov (United States)

Karki, S.; Sultan, M.; Elkadiri, R.; Chouinard, K.

2017-12-01

Numerous occurrences of harmful algal blooms (Karenia Brevis) were reported from Southwest Florida along the coast of Charlotte County, Florida. We are developing data-driven (remote sensing, field, and meteorological data) models to accomplish the following: (1) identify the factors controlling bloom development, (2) forecast bloom occurrences, and (3) make recommendations for monitoring variables that are found to be most indicative of algal bloom occurrences and for identifying optimum locations for monitoring stations. To accomplish these three tasks we completed/are working on the following steps. Firstly, we developed an automatic system for downloading and processing of ocean color data acquired through MODIS Terra and MODIS Aqua products using SeaDAS ocean color processing software. Examples of extracted variables include: chlorophyll a (OC3M), chlorophyll a Generalized Inherent Optical Property (GIOP), chlorophyll a Garver-Siegel- Maritorena (GSM), sea surface temperature (SST), Secchi disk depth, euphotic depth, turbidity index, wind direction and speed, colored dissolved organic material (CDOM). Secondly we are developing a GIS database and a web-based GIS to host the generated remote sensing-based products in addition to relevant meteorological and field data. Examples of the meteorological and field inputs include: precipitation amount and rates, concentrations of nitrogen, phosphorous, fecal coliform and Dissolved Oxygen (DO). Thirdly, we are constructing and validating a multivariate regression model and an artificial neural network model to simulate past algal bloom occurrences using the compiled archival remote sensing, meteorological, and field data. The validated model will then be used to predict the timing and location of algal bloom occurrences. The developed system, upon completion, could enhance the decision making process, improve the citizen's quality of life, and strengthen the local economy.

The impacts of a massive harmful algal bloom along the US west coast in 2015

Science.gov (United States)

Kudela, R. M.; Trainer, V. L.; McCabe, R. M.; Hickey, B. M.; Negrey, K.

2016-02-01

In 2015, a massive bloom of the marine diatom Pseudo-nitzschia, stretching from southern California to southern Alaska, resulted in significant impacts to coastal resources and marine life. This bloom was first detected in early May 2015, when Washington closed its scheduled razor clam digs on coastal beaches. It is the largest and longest-lasting bloom in at least the past 15 years, and concentrations of domoic acid in seawater, some forage fish, and crab samples have been among the highest ever reported for this region. By mid-May, domoic acid concentrations in Monterey Bay, California were 10 to 30 times the level that would be considered high for a normal Pseudo-nitzschia bloom. Impacts to coastal communities and marine life include shellfish and Dungeness crab closures in multiple states, impacting commercial, recreational and subsistence harvesters, anchovy and sardine fishery health advisories in some areas of California, and sea lion strandings in California and Washington. Other marine mammal and bird mortalities have been reported in multiple states, and domoic acid poisoning is a suspected cause. In addition to the spatial extent and toxicity, the bloom has also lasted for many months (ongoing as of September 2015). While the exact causes of the bloom's severity and early onset are not yet known, unusually warm surface water in the Pacific Ocean may be a contributing factor. Here we present an overview of the bloom dynamics and impacts, and preliminary analysis about the bloom initiation and relationship to unusual ocean conditions in 2014-2015.

Remarkable difference in paralytic shellfish poisoning toxin distribution in tissues of pen shell atrina pectinata exposed to toxic red tide bloom

International Nuclear Information System (INIS)

Narceda, Ronald Jefferson A.; Montojo, Ulysses M.; Cayme, Mirriam F.; Borja, Valeriano M.

2011-01-01

Pen shell atrina pectinata is one of the commercially important bivalves in Western Pacific region. In the Philippines, it is marketed as a whole meat or processed by shellfish harvesters to separate the abductor muscle as an export commodity. During blooms of toxic dinoflagellate pyrodinium bahamense var. compressum (Pbc), A. pectinata accumulates paralytic shellfish poisoning (PSP) toxins sometimes exceeding Philippine regulatory limit of 60μgSTXeq/100g tissue and international regulatory limit of 80μgSTXeq/100g tissue for safe human consumption, based on whole tissue analysis. Toxic blooms directly affect the shellfish industry which includes A. pectinata, and this causes not only significant economical losses on shellfish gatherers but also serious public health concerns. In this study, samples of A. pectinata exposed to toxic bloom of Pbc were collected in Sorsogon Bay, Philippines. Bioaccumulation and distribution of PSP toxins were determined in different tissues namely, abductor muscle, mantle, gills, gonads, siphon, stomach and intestine using High Performance Liquid Chromatography post column derivatization method with fluorescence detection. Likewise, green mussels Perna viridis being the sentinel species for PSP monitoring in the Philippines were also collected in the same area and served as control. Interestingly, results showed that the abductor muscle accumulates minimal level of PSP toxins and is several folds lower than the Philippine and international regulatory limits in contrast with the results obtained from P. viridis. Mantle parts showed toxicity values exceeding local regulatory limit and near to go beyond the international regulatory limit. Conversely, the remaining parts showed high toxicity values surpassing both regulation limits. Standard mouse bioassay regulatory used in PSP monitoring in the Philippines was also performed and revealed that the abductor muscle had non-detectable level of toxins. Also, toxicity values from different

Dynamics of a cyanobacterial bloom in a hypereutrophic reservoir ...

African Journals Online (AJOL)

Blooming and non-blooming periods between 2004 and 2006 in a hypereutrophic reservoir, where cyanobacterial blooms have previously been reported to be permanent, presented an opportunity to characterise factors that may favour cyanobacterial dominance. As a bloom developed in May 2004, a shift to dominance by ...

Algal bloom detection, monitoring and prediction. 3. Workshop on public health

Energy Technology Data Exchange (ETDEWEB)

Catena, G; Funari, E [eds.; Istituto Superiore di Sanita' , Rome (Italy). Lab. di Igiene Ambientale

1999-07-01

The report presents articles discussed in the 3. Workshop on Public Health (Rome, Italy) focused on the problem of the harmful algae in the Mediterranean basin with the aim of verifying the possibilities of using remote sensing techniques together with conventional ones. These proceedings report the aim aspects of the problem, as the ecological one, the conventional monitoring techniques, the activities of international organizations and finally some of the current research activities in Italy aimed at using remote sensing techniques. [Italian] Il workshop sulla salute pubblica e' incentrato sul problema delle alghe tossiche marine all'interno del bacino del Mediterraneo con lo scopo di verificare le possibilita' di utilizzare delle tecniche di telerilevamento in modo complementare rispetto a quelle convenzionali. Si affrontano alcuni degli aspetti principali di questa problematica quali l'ecologia, le tecniche convenzionali di monitoraggio, le attivita' di organismi internazionali e infine le attivita' in corso in Italia finalizzate all'utilizzazione delle tecniche di telerilevamento.

Algal bloom detection, monitoring and prediction. 3. Workshop on public health

Energy Technology Data Exchange (ETDEWEB)

Catena, G.; Funari, E. [eds.] [Istituto Superiore di Sanita' , Rome (Italy). Lab. di Igiene Ambientale

1999-07-01

The report presents articles discussed in the 3. Workshop on Public Health (Rome, Italy) focused on the problem of the harmful algae in the Mediterranean basin with the aim of verifying the possibilities of using remote sensing techniques together with conventional ones. These proceedings report the aim aspects of the problem, as the ecological one, the conventional monitoring techniques, the activities of international organizations and finally some of the current research activities in Italy aimed at using remote sensing techniques. [Italian] Il workshop sulla salute pubblica e' incentrato sul problema delle alghe tossiche marine all'interno del bacino del Mediterraneo con lo scopo di verificare le possibilita' di utilizzare delle tecniche di telerilevamento in modo complementare rispetto a quelle convenzionali. Si affrontano alcuni degli aspetti principali di questa problematica quali l'ecologia, le tecniche convenzionali di monitoraggio, le attivita' di organismi internazionali e infine le attivita' in corso in Italia finalizzate all'utilizzazione delle tecniche di telerilevamento.

Jellyfish blooms in China: Dominant species, causes and consequences

International Nuclear Information System (INIS)

Dong Zhijun; Liu Dongyan; Keesing, John K.

2010-01-01

Three jellyfish species, Aurelia aurita, Cyanea nozakii and Nemopilema nomurai, form large blooms in Chinese seas. We report on the distribution and increasing incidence of jellyfish blooms and their consequences in Chinese coastal seas and analyze their relationship to anthropogenically derived changes to the environment in order to determine the possible causes. A. aurita, C. nozakii and N. nomurai form blooms in the temperate Chinese seas including the northern East China Sea, Yellow Sea and Bohai Sea. N. nomurai forms offshore blooms while the other two species bloom mainly in inshore areas. Eutrophication, overfishing, habitat modification for aquaculture and climate change are all possible contributory factors facilitating plausible mechanisms for the proliferation of jellyfish blooms. In the absence of improvement in coastal marine ecosystem health, jellyfish blooms could be sustained and may even spread from the locations in which they now occur.

WATER BLOOM OF BLUEGREEN ALGE IN CARP FISHPOUNDS

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Melita Mihaljević

1996-03-01

Full Text Available The massive development of bluegreen algae (Cyanophyta/Cyanobacteria, the so--called water bloom, is a frequent phenomenon in fishpond ecosystems. This study analyses water bloom development in three carp fishponds owned by a fishbreeding company at Donji Miholjac (Croatia, where one-year-old carps (Cyprinus carpio , were bred in defferent fishstock densities. Analyses of physicallychemical properties of water and phytoplankton biomass were per- formed in fortnight intervals from May till October, 1992. In all there investigated fishponds the water bloom of bluegreen algae developed, but at a different time and showing a different qualitative composition. In the fishpond with fishstock density of 250 kg/ha water bloom consisted of the species Aphanizomenon flos-aquae, and the biggest biomass (131.92 mg/I was found in August. In the fishpond with fishstock density of 437 kg/ha a water bloom consisting of species from the genues Anabaena and species Aphanizomenon flos-aquae developed at the end of July. In the fishpond with the so--called intensive breeding (fishstock density of 750 kg/ha water bloom of the species Microcystis aeruginosa developed as late as September. The beginning of water bloom development was caused by the low value (lower than 7 of the ratio between the quantities of total phosphorus and total nitrogen. However, the qualitative composition of water bloom was influenced by one-year-old carp fingerlings density.

Decadal-scale changes of dinoflagellates and diatoms in the anomalous baltic sea spring bloom.

Directory of Open Access Journals (Sweden)

Riina Klais

Full Text Available The algal spring bloom in the Baltic Sea represents an anomaly from the winter-spring bloom patterns worldwide in terms of frequent and recurring dominance of dinoflagellates over diatoms. Analysis of approximately 3500 spring bloom samples from the Baltic Sea monitoring programs revealed (i that within the major basins the proportion of dinoflagellates varied from 0.1 (Kattegat to >0.8 (central Baltic Proper, and (ii substantial shifts (e.g. from 0.2 to 0.6 in the Gulf of Finland in the dinoflagellate proportion over four decades. During a recent decade (1995-2004 the proportion of dinoflagellates increased relative to diatoms mostly in the northernmost basins (Gulf of Bothnia, from 0.1 to 0.4 and in the Gulf of Finland, (0.4 to 0.6 which are typically ice-covered areas. We hypothesize that in coastal areas a specific sequence of seasonal events, involving wintertime mixing and resuspension of benthic cysts, followed by proliferation in stratified thin layers under melting ice, favors successful seeding and accumulation of dense dinoflagellate populations over diatoms. This head-start of dinoflagellates by the onset of the spring bloom is decisive for successful competition with the faster growing diatoms. Massive cyst formation and spreading of cyst beds fuel the expanding and ever larger dinoflagellate blooms in the relatively shallow coastal waters. Shifts in the dominant spring bloom algal groups can have significant effects on major elemental fluxes and functioning of the Baltic Sea ecosystem, but also in the vast shelves and estuaries at high latitudes, where ice-associated cold-water dinoflagellates successfully compete with diatoms.

Satellite monitoring of cyanobacterial harmful algal bloom frequency in recreational waters and drinking water sources

Science.gov (United States)

Cyanobacterial harmful algal blooms (cyanoHABs) cause extensive problems in lakes worldwide, including human and ecological health risks, anoxia and fish kills, and taste and odor problems. CyanoHABs are a particular concern because of their dense biomass and the risk of expos...

Peculiarities of the Woody Plants Re-Bloom

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Opalko Olga Anatolievna

2015-09-01

Full Text Available The data of literary sources concerning the bloom of angiosperm plants and deviation in the development of a flower and inflorescence, in particular untimely flowering, was generalized; our observation results of some peculiarities of re-bloom of woody plants in the National Dendrological Park “Sofiyivka” of NAS of Ukraine (NDP “Sofiyivka” were discussed. The flowering process was formed during a long-term evolution of a propagation system of angiosperm plants as a basis of fertilization and further fruit and seed development. As a result of vernalization and photoperiodism reactions, flowering (under regular conditions occurs in the most favorable period for pollination and fertilization of every plant. However, various deviations, in particular, the untimely (most frequently double, sometimes three- and four-fold flowering occurs in this perfect process of generative organ formation of angiosperm plants. An increased number of reports about re-bloom (at the end of summer – at the beginning of fall of the representatives of various woody plant species whose flowers usually blossom in May-June prompts the analysis of the available information concerning the mechanisms of flowering and the causes which lead to deviation of flowering processes. Flowering of the woody plant representatives of the collection fund of the NDP “Sofiyivka” was studied; statistics about re-bloom in different cities of Ukraine were monitored. The classification of re-bloom facts was carried out according to V.L. Vitkovskiy (1984. Although this classification has mostly a stated nature, it was good enough when being formulated and, with certain conditions, it can be applied nowadays. Accordingly, using this classification, abnormal cases can include facts of early summer-fall flowering and early winter flowering. A late spring flowering can be adaptive response of damaged plants to exogenous stresses, due to which the probability of sexual propagation remains

Unveiling the transcriptional features associated with coccolithovirus infection of natural Emiliania huxleyi blooms.

Science.gov (United States)

Pagarete, António; Le Corguillé, Gildas; Tiwari, Bela; Ogata, Hiroyuki; de Vargas, Colomban; Wilson, William H; Allen, Michael J

2011-12-01

Lytic viruses have been implicated in the massive cellular lysis observed during algal blooms, through which they assume a prominent role in oceanic carbon and nutrient flows. Despite their impact on biogeochemical cycling, the transcriptional dynamics of these important oceanic events is still poorly understood. Here, we employ an oligonucleotide microarray to monitor host (Emiliania huxleyi) and virus (coccolithovirus) transcriptomic features during the course of E. huxleyi blooms induced in seawater-based mesocosm enclosures. Host bloom development and subsequent coccolithovirus infection was associated with a major shift in transcriptional profile. In addition to the expected metabolic requirements typically associated with viral infection (amino acid and nucleotide metabolism, as well as transcription- and replication-associated functions), the results strongly suggest that the manipulation of lipid metabolism plays a fundamental role during host-virus interaction. The results herein reveal the scale, so far massively underestimated, of the transcriptional domination that occurs during coccolithovirus infection in the natural environment. © 2011 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

Comparative Analysis of Flower Volatiles from Nine Citrus at Three Blooming Stages

Directory of Open Access Journals (Sweden)

Muhammad Azam

2013-11-01

Full Text Available Volatiles from flowers at three blooming stages of nine citrus cultivars were analyzed by headspace-solid phase microextraction (HS-SPME-GC-MS. Up to 110 volatiles were detected, with 42 tentatively identified from citrus flowers for the first time. Highest amounts of volatiles were present in fully opened flowers of most citrus, except for pomelos. All cultivars were characterized by a high percentage of either oxygenated monoterpenes or monoterpene hydrocarbons, and the presence of a high percentage of nitrogen containing compounds was also observed. Flower volatiles varied qualitatively and quantitatively among citrus types during blooming. Limonene was the most abundant flower volatile only in citrons; α-citral and β-citral ranked 2nd and 3rd only for Bergamot, and unopened flowers of Ponkan had a higher amount of linalool and β-pinene while much lower amount of γ-terpinene and p-cymene than Satsuma. Taking the average of all cultivars, linalool and limonene were the top two volatiles for all blooming stages; β-pinene ranked 3rd in unopened flowers, while indole ranked 3rd for half opened and fully opened flower volatiles. As flowers bloomed, methyl anthranilate increased while 2-hexenal and p-cymene decreased. In some cases, a volatile could be high in both unopened and fully opened flowers but low in half opened ones. Through multivariate analysis, the nine citrus cultivars were clustered into three groups, consistent with the three true citrus types. Furthermore, an influence of blooming stages on clustering was observed, especially with hybrids Satsuma and Huyou. Altogether, it was suggested that flower volatiles can be suitable markers for revealing the genetic relationships between citrus cultivars but the same blooming stage needs to be strictly controlled.

How physiological and physical processes contribute to the phenology of cyanobacterial blooms in large shallow lakes: A new Euler-Lagrangian coupled model.

Science.gov (United States)

Feng, Tao; Wang, Chao; Wang, Peifang; Qian, Jin; Wang, Xun

2018-09-01

Cyanobacterial blooms have emerged as one of the most severe ecological problems affecting large and shallow freshwater lakes. To improve our understanding of the factors that influence, and could be used to predict, surface blooms, this study developed a novel Euler-Lagrangian coupled approach combining the Eulerian model with agent-based modelling (ABM). The approach was subsequently verified based on monitoring datasets and MODIS data in a large shallow lake (Lake Taihu, China). The Eulerian model solves the Eulerian variables and physiological parameters, whereas ABM generates the complete life cycle and transport processes of cyanobacterial colonies. This model ensemble performed well in fitting historical data and predicting the dynamics of cyanobacterial biomass, bloom distribution, and area. Based on the calculated physical and physiological characteristics of surface blooms, principal component analysis (PCA) captured the major processes influencing surface bloom formation at different stages (two bloom clusters). Early bloom outbreaks were influenced by physical processes (horizontal transport and vertical turbulence-induced mixing), whereas buoyancy-controlling strategies were essential for mature bloom outbreaks. Canonical correlation analysis (CCA) revealed the combined actions of multiple environment variables on different bloom clusters. The effects of buoyancy-controlling strategies (ISP), vertical turbulence-induced mixing velocity of colony (VMT) and horizontal drift velocity of colony (HDT) were quantitatively compared using scenario simulations in the coupled model. VMT accounted for 52.9% of bloom formations and maintained blooms over long periods, thus demonstrating the importance of wind-induced turbulence in shallow lakes. In comparison, HDT and buoyancy controlling strategies influenced blooms at different stages. In conclusion, the approach developed here presents a promising tool for understanding the processes of onshore/offshore algal

The paradox of algal blooms in oligotrophic waters

Science.gov (United States)

Sundareshwar, P. V.; Upadhyay, S.; Abessa, M. B.; Honomichl, S.; Berdanier, B.; Spaulding, S.; Sandvik, C.; Trennepohl, A.

2010-12-01

Nutrient inputs to streams and lakes, primarily from anthropogenic sources, lead to eutrophic conditions that favor algal blooms with undesirable consequences. In contrast, low nutrient or oligotrophic waters rarely support algal blooms; such ecosystems are typically lower in productivity. Since the mid-1980’s however, the diatom Didymosphenia geminata has dramatically expanded its range colonizing oligotrophic rivers worldwide with blooms appearing as thick benthic mats. This recent global occurrence of Didymosphenia geminata blooms in temperate rivers has been perplexing in its pace of spread and the paradoxical nature of the nuisance growths. The blooms occur primarily in oligotrophic flowing waters, where phosphorus (P) availability often limits primary production. We present a biogeochemical process by which D. geminata mats adsorb both P and iron (Fe) from flowing waters and make P available for cellular uptake. The adsorbed P becomes bioavailable through biogeochemical processes that occur within the mat. The biogeochemical processes observed here while well accepted in benthic systems are novel for algal blooms in lotic habits. Enzymatic and bacterial processes such as Fe and sulfate reduction can release the adsorbed P and increase its bioavailability, creating a positive feedback between total stalk biomass and nutrient availability. Stalk affinity for Fe, Fe-P biogeochemistry, and interaction between watershed processes and climatic setting explain the paradoxical blooms, and the recent global spread of this invasive aquatic species. At a broader scale the study also implies that such algal blooms in oligotrophic environments can fundamentally alter the retention and longitudinal transfer of important nutrients such as P in streams and rivers.

Toxic Microalgal Blooms: What Can Nuclear Techniques Provide for Their Management?

Energy Technology Data Exchange (ETDEWEB)

Reguera, B. [Instituto Espanol de Oceanografia, Centro Oceanografico de Vigo (Spain); Boisson, F. [International Atomic Energy Agency, Environment Laboratories (Monaco); Darius, H. T. [Institut Louis Malarde, Laboratoire de Recherche sur les Microalgues Toxiques, Tahiti, French Polynesia (France); Dechraoui Bottein, M. -Y. [NOAA, National Ocean Service, Marine Biotoxins Programme, Center for Coastal Environmental Health and Biomolecular Research, Charleston, SC (United States)

2013-07-15

Some harmful algal blooms (HABs) produce potent toxins that accumulate in shellfish and fish and represent a major threat to human health, international trade and sustainable coastal fisheries development. In the context of climate change and displacement of endemic toxigenic species (via ship ballast waters and other vectors) to new coastal areas, HABs appear to be more frequent and widespread. The IAEA Marine Environment Laboratory and its partners have been developing and transferring isotopic based analytical methods and instrumentation for monitoring HAB species, their biotoxins, and radiometric dating of sediment cores. The extremely sensitive and robust Receptor Binding Assay (RBA) for toxins associated with Paralytic Shellfish Poisoning (PSP) and Ciguatera Fish Poisoning (CFP) provides an alternative method to the standard mouse bioassay, and radiometric sediment core dating combined with fossil cyst abundance allows reconstruction of the prior history of blooms and their relationship to climate. (author)

Subsurface phytoplankton blooms fuel pelagic production in the North Sea

DEFF Research Database (Denmark)

Richardson, Kathrine; Visser, Andre; Pedersen, Flemming

2000-01-01

The seasonal phytoplankton biomass distribution pattern in stratified temperate marine waters is traditionally depicted as consisting of spring and autumn blooms. The energy source supporting pelagic summer production is believed to be the spring bloom. However, the spring bloom disappears...... relatively quickly from the water column and a large proportion of the material sedimenting to the bottom following the spring bloom is often comprised of intact phytoplankton cells. Thus, it is easy to argue that the spring bloom is fueling the energy demands of the benthos, but more difficult to argue...... convincingly that energy fixed during the spring bloom is fueling the pelagic production occurring during summer months. We argue here that periodic phytoplankton blooms are occurring during the summer in the North Sea at depths of >25 m and that the accumulated new production [sensu (Dugdale and Goering...

Algal blooms: a perspective from the coasts of India

Digital Repository Service at National Institute of Oceanography (India)

DeSilva, M.S.; Anil, A.C.; Naik, R.K.; DeCosta, P.M.

Algal blooms have been documented along the west and east coasts of India. A review of bloom occurrences in Indian waters from 1908 to 2009 points out that a total of 101 cases have been reported. A comparison of the bloom cases reported before...

Bacterial community transcription patterns during a marine phytoplankton bloom.

Science.gov (United States)

Rinta-Kanto, Johanna M; Sun, Shulei; Sharma, Shalabh; Kiene, Ronald P; Moran, Mary Ann

2012-01-01

Bacterioplankton consume a large proportion of photosynthetically fixed carbon in the ocean and control its biogeochemical fate. We used an experimental metatranscriptomics approach to compare bacterial activities that route energy and nutrients during a phytoplankton bloom compared with non-bloom conditions. mRNAs were sequenced from duplicate bloom and control microcosms 1 day after a phytoplankton biomass peak, and transcript copies per litre of seawater were calculated using an internal mRNA standard. Transcriptome analysis revealed a potential novel mechanism for enhanced efficiency during carbon-limited growth, mediated through membrane-bound pyrophosphatases [V-type H(+)-translocating; hppA]; bloom bacterioplankton participated less in this metabolic energy scavenging than non-bloom bacterioplankton, with possible implications for differences in growth yields on organic substrates. Bloom bacterioplankton transcribed more copies of genes predicted to increase cell surface adhesiveness, mediated by changes in bacterial signalling molecules related to biofilm formation and motility; these may be important in microbial aggregate formation. Bloom bacterioplankton also transcribed more copies of genes for organic acid utilization, suggesting an increased importance of this compound class in the bioreactive organic matter released during phytoplankton blooms. Transcription patterns were surprisingly faithful within a taxon regardless of treatment, suggesting that phylogeny broadly predicts the ecological roles of bacterial groups across 'boom' and 'bust' environmental backgrounds. © 2011 Society for Applied Microbiology and Blackwell Publishing Ltd.

Plankton bloom controlled by horizontal stirring

Science.gov (United States)

McKiver, W.; Neufeld, Z.; Scheuring, I.

2009-10-01

Here we show a simple mechanism in which changes in the rate of horizontal stirring by mesoscale ocean eddies can trigger or suppress plankton blooms and can lead to an abrupt change in the average plankton density. We consider a single species phytoplankton model with logistic growth, grazing and a spatially non-uniform carrying capacity. The local dynamics have multiple steady states for some values of the carrying capacity that can lead to localized blooms as fluid moves across the regions with different properties. We show that for this model even small changes in the ratio of biological timescales relative to the flow timescales can greatly enhance or reduce the global plankton productivity. Thus, this may be a possible mechanism in which changes in horizontal mixing can trigger plankton blooms or cause regime shifts in some oceanic regions. Comparison between the spatially distributed model and Lagrangian simulations considering temporal fluctuations along fluid trajectories, demonstrates that small scale transport processes also play an important role in the development of plankton blooms with a significant influence on global biomass.

A harmful algal bloom of Karenia brevis in the northeastern Gulf of Mexico as revealed by MODIS and VIIRS: a comparison.

Science.gov (United States)

Hu, Chuanmin; Barnes, Brian B; Qi, Lin; Corcoran, Alina A

2015-01-28

The most recent Visible Infrared Imager Radiometer Suite (VIIRS) is not equipped with a spectral band to detect solar-stimulated phytoplankton fluorescence. The lack of such a band may affect the ability of VIIRS to detect and quantify harmful algal blooms (HABs) in coastal waters rich in colored dissolved organic matter (CDOM) because of the overlap of CDOM and chlorophyll absorption within the blue-green spectrum. A recent HAB dominated by the toxin-producing dinoflagellate Karenia brevis in the northeastern Gulf of Mexico, offshore of Florida's Big Bend region, allowed for comparison of the capacities of VIIRS and Moderate Resolution Imaging Spectroradiometer (MODIS) to detect blooms in CDOM-rich waters. Both VIIRS and MODIS showed general consistency in mapping the CDOM-rich dark water, which measured a maximum area of 8900 km2 by mid-July 2014. However, within the dark water, only MODIS allowed detection of bloom patches-as indicated by high normalized fluorescence line height (nFLH). Field surveys between late July and mid-September confirmed Karenia brevis at bloom abundances up to 20 million cells·L(-1) within these patches. The bloom patches were well captured by the MODIS nFLH images, but not by the default chlorophyll a concentration (Chla) images from either MODIS or VIIRS. Spectral analysis showed that VIIRS could not discriminate these high-phytoplankton water patches within the dark water due to its lack of fluorescence band. Such a deficiency may be overcome with new algorithms or future satellite missions such as the U.S. NASA's Pre-Aerosol-Clouds-Ecology mission and the European Space Agency's Sentinel-3 mission.

Proteomic Analysis of Hepatic Tissue of Cyprinus carpio L. Exposed to Cyanobacterial Blooms in Lake Taihu, China

Science.gov (United States)

Jiang, Jinlin; Wang, Xiaorong; Shan, Zhengjun; Yang, Liuyan; Zhou, Junying; Bu, Yuanqin

2014-01-01

With the rapid development of industry and agriculture and associated pollution, the cyanobacterial blooms in Lake Taihu have become a major threat to aquatic wildlife and human health. In this study, the ecotoxicological effects of cyanobacterial blooms on cage-cultured carp (Cyprinus carpio L.) in Meiliang Bay of Lake Taihu were investigated. Microcystins (MCs), major cyanobacterial toxins, have been detected in carp cultured at different experimental sites of Meiliang Bay. We observed that the accumulation of MCs in carp was closely associated with several environmental factors, including temperature, pH value, and density of cyanobacterial blooms. The proteomic profile of carp liver exposed to cyanobacterial blooms was analyzed using two-dimensional difference in-gel electrophoresis (2D-DIGE) and mass spectrometry. The toxic effects of cyanobacterial blooms on carp liver were similar to changes caused by MCs. MCs were transported into liver cells and induced the excessive production of reactive oxygen species (ROS). MCs and ROS inhibited protein phosphatase and aldehyde dehydrogenase (ALDH), directly or indirectly resulting in oxidative stress and disruption of the cytoskeleton. These effects further interfered with metabolic pathways in the liver through the regulation of series of related proteins. The results of this study indicated that cyanobacterial blooms pose a major threat to aquatic wildlife in Meiliang Bay in Lake Taihu. These results provided evidence of the molecular mechanisms underlying liver damage in carp exposed to cyanobacterial blooms. PMID:24558380

Distribution and recurrence of phytoplankton blooms around South Georgia, Southern Ocean

Directory of Open Access Journals (Sweden)

I. Borrione

2013-01-01

Full Text Available South Georgia phytoplankton blooms are amongst the largest of the Southern Ocean and are associated with a rich ecosystem and strong atmospheric carbon drawdown. Both aspects depend on the intensity of blooms, but also on their regularity. Here we use data from 12 yr of SeaWiFS (Sea-viewing Wide Field-of-view Sensor ocean colour imagery and calculate the frequency of bloom occurrence (FBO to re-examine spatial and temporal bloom distributions. We find that upstream of the island and outside the borders of the Georgia Basin, blooms occurred in less than 4 out of the 12 yr (FBO < 4. In contrast, FBO was mostly greater than 8 downstream of the island, i.e., to the north and northwest, and in places equal to 12, indicating that blooms occurred every year. The typical bloom area, defined as the region where blooms occurred in at least 8 out of the 12 yr, covers the entire Georgia Basin and the northern shelf of the island. The time series of surface chlorophyll a (Chl a concentrations averaged over the typical bloom area shows that phytoplankton blooms occurred in every year between September 1997 and September 2010, and that Chl a values followed a clear seasonal cycle, with concentration peaks around December followed in many years by a second peak during late austral summer or early autumn, suggesting a bi-modal bloom pattern. The bloom regularity we describe here is in contrast with results of Park et al. (2010 who used a significantly different study area including regions that almost never exhibit bloom conditions.

Intensive aggregate formation with low vertical flux during an upwelling-induced diatom bloom

DEFF Research Database (Denmark)

Kiørboe, Thomas; Tiselius, P.; Mitchell-Innes, B.

1998-01-01

of turbulent shear in the ocean such stickiness coefficients predict very high specific coagulation rates (0.3 d(-1)). In situ video observation demonstrated the occurrence of abundant diatom aggregates with surface water concentrations between 1,000 and 3,000 ppm. Despite the very high concentration......The surfaces of most pelagic diatoms are sticky at times and may therefore form rapidly settling aggregates by physical coagulation. Stickiness and aggregate formation may be particularly adaptive in upwelling systems by allowing the retention of diatom populations in the vicinity of the upwelling...... center. We therefore hypothesized that upwelling diatom blooms are terminated by aggregate formation and rapid sedimentation. We monitored the development of a maturing diatom (mainly Chaetoceros spp.) bloom in the Benguela upwelling current during 7 d in February. Chlorophyll concentrations remained...

Surface layer and bloom dynamics observed with the Prince William Sound Autonomous Profiler

Science.gov (United States)

Campbell, R. W.

2016-02-01

As part of a recent long term monitoring effort, deployments of a WETLabs Autonomous Moored Profiler (AMP) began Prince William Sound (PWS) in 2013. The PWS AMP consists of a positively buoyant instrument frame, with a winch and associated electronics that profiles the frame from a park depth (usually 55 m) to the surface by releasing and retrieving a thin UHMWPE tether; it generally conducts a daily cast and measures temperature, salinity, chlorophyll-a fluorescence, turbidity, and oxygen and nitrate concentrations. Upward and downward looking ADCPs are mounted on a float below the profiler, and an in situ plankton imager is in development and will be installed in 2016. Autonomous profilers are a relatively new technology, and early deployments experienced a number of failures from which valuable lessons may be learned. Nevertheless, an unprecedented time series of the seasonal biogeochemical procession in the surface waters coastal Gulf of Alaska was collected in 2014 and 2015. The northern Gulf of Alaska has experienced a widespread warm anomaly since early 2014, and surface layer temperature anomalies in PWS were strongly positive during winter 2014. The spring bloom observed by the profiler began 2-3 weeks earlier than average, with surface nitrate depleted by late April. Although surface temperatures were still above average in 2015, bloom timing was much later, with a short vigorous bloom in late April and a subsurface bloom in late May that coincided with significant nitrate drawdown. As well as the vernal blooms, wind-driven upwelling events lead to several small productivity pulses that were evident in changes in nitrate and oxygen concentrations, and chlorophyll-a fluorescence. As well as providing a mechanistic understanding of surface layer biogeochemistry, high frequency observations such as these put historical observations in context, and provide new insights into the scales of variability in the annual cycles of the surface ocean in the North

The development and decline of phytoplankton blooms in the southern Benguela upwelling region

International Nuclear Information System (INIS)

Brown, P.C.

1986-10-01

Productivity/chlorophyll a relationship are investigated with a view to estimating phytoplankton productivity from extensive chlorophyll a measurements in the southern Benguela region. Phytoplankton bloom dynamics in newly upwelled water off the Cape Peninsula are investigated on five different occasions during the upwelling season. A drogue was used to tag a 'parcel' of upwelled water which was monitored for between 4 and 8 days. In upwelling source water, mean chlorophyll a concentrations were typically low (0.7 mg.m -3 ) and nutrient concentrations were high (nitrates, silicates and phosphates were 20.8, 16.6 and 1.88 mmol.m -3 respectively). Along the drogue tracks nutrients decreased rapidly in the euphotic zone as chlorophyll increased to peak at concentrations of up to 26 mg.m -3 . Elemental changes in nitrates, silicates, phosphates and oxygen were used to estimate primary productivity. These 'Redfield productivity estimates' were similar to 14 C-uptake productivity but lower than estimates obtained from changes in particle volume. Daily rates of 14 C-uptake water column productivity ranged between 0.94 and 14.01 g C.m -2 .d -1 (mean 3.80 g C.m -2 .d -1 ) and were similar to or higher than productivity estimates reported for other upwelling areas. Phytoplankton biomass in the upper 50 metres ranged between 8 and 506 mg chll a. m -2 (mean 208 mg chll a.m -2 ). The temporal scale of phytoplankton bloom development was investigated in terms of changes in chlorophyll a concentrations in the euphotic zone. The build up and decline of the primary phytoplankton (diatom) bloom in newly upwelled water occurred within 6-8 days. The initiation of blooming was controlled by the stability of the water body. The decline of the bloom was associated with reduced nutrient levels and is considered to result mainly from phytoplankton cells sinking out of the surface layers

A multiomics approach to study the microbiome response to phytoplankton blooms.

Science.gov (United States)

Song, Liyan

2017-06-01

Phytoplankton blooms are predictable features of marine and freshwater habitats. Despite a good knowledge base of the environmental factors controlling blooms, complex interactions between the bacterial and archaeal communities and phytoplankton bloom taxa are only now emerging. Here, the current research on bacterial community's structural and functional response to phytoplankton blooms is reviewed and discussed and further research is proposed. More attention should be paid on structure and function of autotrophic bacteria and archaea during phytoplankton blooms. A multiomics integration approach is needed to investigate bacterial and archaeal communities' diversity, metabolic diversity, and biogeochemical functions of microbial interactions during phytoplankton blooms.

Weather during bloom affects pollination and yield of highbush blueberry.

Science.gov (United States)

Tuell, Julianna K; Isaacs, Rufus

2010-06-01

Weather plays an important role in spring-blooming fruit crops due to the combined effects on bee activity, flower opening, pollen germination, and fertilization. To determine the effects of weather on highbush blueberry, Vaccinium corymbosum L., productivity, we monitored bee activity and compared fruit set, weight, and seed number in a field stocked with honey bees, Apis mellifera L., and common eastern bumble bees, Bombus impatiens (Cresson). Flowers were subjected to one of five treatments during bloom: enclosed, open, open during poor weather only, open during good weather only, or open during poor and good weather. Fewer bees of all types were observed foraging and fewer pollen foragers returned to colonies during poor weather than during good weather. There were also changes in foraging community composition: honey bees dominated during good weather, whereas bumble bees dominated during poor weather. Berries from flowers exposed only during poor weather had higher fruit set in 1 yr and higher berry weight in the other year compared with enclosed clusters. In both years, clusters exposed only during good weather had > 5 times as many mature seeds, weighed twice as much, and had double the fruit set of those not exposed. No significant increase over flowers exposed during good weather was observed when clusters were exposed during good and poor weather. Our results are discussed in terms of the role of weather during bloom on the contribution of bees adapted to foraging during cool conditions.

Bloom dynamics and life cycle strategies of two toxic dinoflagellates in a coastal upwelling system (NW Iberian Peninsula)

Science.gov (United States)

Bravo, Isabel; Fraga, Santiago; Isabel Figueroa, Rosa; Pazos, Yolanda; Massanet, Ana; Ramilo, Isabel

2010-02-01

A study of Gymnodinium catenatum and Alexandrium minutum blooms on the Galician coast was conducted from 2005 to 2007 in order to increase knowledge of the mechanisms governing recurrent blooms of these species. Considerable differences in their bloom dynamics were observed. G. catenatum blooms occurred in autumn and winter, following the pattern previously reported in the literature: they began off-shore and were advected to the Galician rias when a relaxation of the coastal upwelling occurred. On the other hand, A. minutum blooms developed inside embayments in spring and summer during the upwelling season and were associated with water stability and stratification. Both the vegetative population and the cyst distribution of A. minutum were related to less saline water from freshwater river outputs, which support a saline-gradient relationship postulated herein for this species. Dinoflagellates may produce both long-term double-walled cysts (resting) and short-term pellicle cysts. Resting cyst deposition and distribution in sediments showed that seeding occurred during the blooms of both species. However, the relationship between the cyst distribution in the sediments in Baiona Bay and the intensity and occurrence of G. catenatum blooms, suggests that the latter are not directly related to resting cyst germination. Moreover, the results presented in the present study point to other difference between the two species, such as the detection of pellicle cysts only for A. minutum. Finally, we discuss how the life cycle strategies of these two species may help to explain the different mechanisms of bloom formation reported herein.

Prevention of Cyanobacterial Blooms Using Nanosilica: A Biomineralization-Inspired Strategy.

Science.gov (United States)

Xiong, Wei; Tang, Yiming; Shao, Changyu; Zhao, Yueqi; Jin, Biao; Huang, Tingting; Miao, Ya'nan; Shu, Lei; Ma, Weimin; Xu, Xurong; Tang, Ruikang

2017-11-07

Cyanobacterial blooms represent a significant threat to global water resources because blooming cyanobacteria deplete oxygen and release cyanotoxins, which cause the mass death of aquatic organisms. In nature, a large biomass volume of cyanobacteria is a precondition for a bloom, and the cyanobacteria buoyancy is a key parameter for inducing the dense accumulation of cells on the water surface. Therefore, blooms will likely be curtailed if buoyancy is inhibited. Inspired by diatoms with naturally generated silica shells, we found that silica nanoparticles can be spontaneously incorporated onto cyanobacteria in the presence of poly(diallyldimethylammonium chloride), a cationic polyelectrolyte that can simulate biosilicification proteins. The resulting cyanobacteria-SiO 2 complexes can remain sedimentary in water. This strategy significantly inhibited the photoautotrophic growth of the cyanobacteria and decreased their biomass accumulation, which could effectively suppress harmful bloom events. Consequently, several of the adverse consequences of cyanobacteria blooms in water bodies, including oxygen consumption and microcystin release, were significantly alleviated. Based on the above results, we propose that the silica nanoparticle treatment has the potential for use as an efficient strategy for preventing cyanobacteria blooms.

Harmful Algal Blooms

Science.gov (United States)

Graham, Jennifer L.

2007-01-01

What are Harmful Algal Blooms (HABs)? Freshwater and marine harmful algal blooms (HABs) can occur anytime water use is impaired due to excessive accumulations of algae. HAB occurrence is affected by a complex set of physical, chemical, biological, hydrological, and meteorological conditions making it difficult to isolate specific causative environmental factors. Potential impairments include reduction in water quality, accumulation of malodorous scums in beach areas, algal production of toxins potent enough to poison both aquatic and terrestrial organisms, and algal production of taste-and-odor compounds that cause unpalatable drinking water and fish. HABs are a global problem, and toxic freshwater and (or) marine algae have been implicated in human and animal illness and death in over 45 countries worldwide and in at least 27 U.S. States (Yoo and others, 1995; Chorus and Bartram, 1999; Huisman and others, 2005).

Seawater reverse osmosis desalination and (harmful) algal blooms

KAUST Repository

Villacorte, Loreen O.; Tabatabai, S. Assiyeh Alizadeh; Anderson, Donald M.; Amy, Gary L.; Schippers, Jan Cornelis; Kennedy, Maria Dolores

2015-01-01

This article reviews the occurrence of HABs in seawater, their effects on the operation of seawater reverse osmosis (SWRO) plants, the indicators for quantifying/predicting these effects, and the pretreatment strategies for mitigating operational issues during algal blooms. The potential issues in SWRO plants during HABs are particulate/organic fouling of pretreatment systems and biological fouling of RO membranes, mainly due to accumulation of algal organic matter (AOM). The presence of HAB toxins in desalinated water is also a potential concern but only at very low concentrations. Monitoring algal cell density, AOM concentrations and membrane fouling indices is a promising approach to assess the quality of SWRO feedwater and performance of the pretreatment system. When geological condition is favourable, subsurface intake can be a robust pretreatment for SWRO during HABs. Existing SWRO plants with open intake and are fitted with granular media filtration can improve performance in terms of capacity and product water quality, if preceded by dissolved air flotation or sedimentation. However, the application of advanced pretreatment using ultrafiltration membrane with in-line coagulation is often a better option as it is capable of maintaining stable operation and better RO feed water quality during algal bloom periods with significantly lower chemical consumption.

Seawater reverse osmosis desalination and (harmful) algal blooms

KAUST Repository

Villacorte, Loreen O.

2015-03-01

This article reviews the occurrence of HABs in seawater, their effects on the operation of seawater reverse osmosis (SWRO) plants, the indicators for quantifying/predicting these effects, and the pretreatment strategies for mitigating operational issues during algal blooms. The potential issues in SWRO plants during HABs are particulate/organic fouling of pretreatment systems and biological fouling of RO membranes, mainly due to accumulation of algal organic matter (AOM). The presence of HAB toxins in desalinated water is also a potential concern but only at very low concentrations. Monitoring algal cell density, AOM concentrations and membrane fouling indices is a promising approach to assess the quality of SWRO feedwater and performance of the pretreatment system. When geological condition is favourable, subsurface intake can be a robust pretreatment for SWRO during HABs. Existing SWRO plants with open intake and are fitted with granular media filtration can improve performance in terms of capacity and product water quality, if preceded by dissolved air flotation or sedimentation. However, the application of advanced pretreatment using ultrafiltration membrane with in-line coagulation is often a better option as it is capable of maintaining stable operation and better RO feed water quality during algal bloom periods with significantly lower chemical consumption.

Emergence of Algal Blooms: The Effects of Short-Term Variability in Water Quality on Phytoplankton Abundance, Diversity, and Community Composition in a Tidal Estuary

Directory of Open Access Journals (Sweden)

Todd A. Egerton

2014-01-01

Full Text Available Algal blooms are dynamic phenomena, often attributed to environmental parameters that vary on short timescales (e.g., hours to days. Phytoplankton monitoring programs are largely designed to examine long-term trends and interannual variability. In order to better understand and evaluate the relationships between water quality variables and the genesis of algal blooms, daily samples were collected over a 34 day period in the eutrophic Lafayette River, a tidal tributary within Chesapeake Bay’s estuarine complex, during spring 2006. During this period two distinct algal blooms occurred; the first was a cryptomonad bloom and this was followed by a bloom of the mixotrophic dinoflagellate, Gymnodinium instriatum. Chlorophyll a, nutrient concentrations, and physical and chemical parameters were measured daily along with phytoplankton abundance and community composition. While 65 phytoplankton species from eight major taxonomic groups were identified in samples and total micro- and nano-phytoplankton cell densities ranged from 5.8 × 106 to 7.8 × 107 cells L−1, during blooms, cryptomonads and G. instriatum were 91.6% and 99.0%, respectively, of the total phytoplankton biomass during blooms. The cryptomonad bloom developed following a period of rainfall and concomitant increases in inorganic nitrogen concentrations. Nitrate, nitrite and ammonium concentrations 0 to 5 days prior were positively lag-correlated with cryptomonad abundance. In contrast, the G. insriatum bloom developed during periods of low dissolved nitrogen concentrations and their abundance was negatively correlated with inorganic nitrogen concentrations.

The Blooming Anatomy Tool (BAT): A Discipline-Specific Rubric for Utilizing Bloom's Taxonomy in the Design and Evaluation of Assessments in the Anatomical Sciences

Science.gov (United States)

Thompson, Andrew R.; O'Loughlin, Valerie D.

2015-01-01

Bloom's taxonomy is a resource commonly used to assess the cognitive level associated with course assignments and examination questions. Although widely utilized in educational research, Bloom's taxonomy has received limited attention as an analytical tool in the anatomical sciences. Building on previous research, the Blooming Anatomy Tool (BAT)…

Byatt versus Bloom

DEFF Research Database (Denmark)

Børch, Marianne

2016-01-01

Antonia Byatt's Possession takes issue with Harold Bloom's famous claim that creation - including an author's creative reading of an intertext - entails a violent encounter. Byatt's book suggests a more positive Construction of the process by which tradition is transformed in transmission....

Summer heatwaves promote blooms of harmful cyanobacteria

NARCIS (Netherlands)

K.D Joehnk; J. Huisman; J. Sharples; B.P. Sommeijer (Ben); P.M. Visser (Petra); J.M. Stroom

2008-01-01

htmlabstractDense surface blooms of toxic cyanobacteria in eutrophic lakes may lead to mass mortalities of fish and birds, and provide a serious health threat for cattle, pets, and humans. It has been argued that global warming may increase the incidence of harmful algal blooms. Here, we report on a

Summer heatwaves promote blooms of harmful cyanobacteria

NARCIS (Netherlands)

Jöhnk, K.D.; Huisman, J.; Sharples, J.; Sommeijer, B.; Visser, P.M.; Stroom, J.M.

2008-01-01

Dense surface blooms of toxic cyanobacteria in eutrophic lakes may lead to mass mortalities of fish and birds, and provide a serious health threat for cattle, pets, and humans. It has been argued that global warming may increase the incidence of harmful algal blooms. Here, we report on a lake

Deep-Learning-Based Approach for Prediction of Algal Blooms

Directory of Open Access Journals (Sweden)

Feng Zhang

2016-10-01

Full Text Available Algal blooms have recently become a critical global environmental concern which might put economic development and sustainability at risk. However, the accurate prediction of algal blooms remains a challenging scientific problem. In this study, a novel prediction approach for algal blooms based on deep learning is presented—a powerful tool to represent and predict highly dynamic and complex phenomena. The proposed approach constructs a five-layered model to extract detailed relationships between the density of phytoplankton cells and various environmental parameters. The algal blooms can be predicted by the phytoplankton density obtained from the output layer. A case study is conducted in coastal waters of East China using both our model and a traditional back-propagation neural network for comparison. The results show that the deep-learning-based model yields better generalization and greater accuracy in predicting algal blooms than a traditional shallow neural network does.

Winter atmospheric circulation signature for the timing of the spring bloom of diatoms in the North Sea

Science.gov (United States)

Lohmann, Gerrit; Wiltshire, Karen

2015-04-01

Analysing long-term diatom data from the German Bight and observational climate data for the period 1962-2005, we found a close connection of the inter-annual variation of the timing of the spring bloom with the boreal winter atmospheric circulation. We examined the fact that high diatom counts of the spring bloom tended to occur later when the atmospheric circulation was characterized by winter blocking over Scandinavia. The associated pattern in the sea level pressure showed a pressure dipole with two centres located over the Azores and Norway and was tilted compared to the North Atlantic Oscillation. The bloom was earlier when the cyclonic circulation over Scandinavia allowed an increased inflow of Atlantic water into the North Sea which is associated with clearer, more marine water, and warmer conditions. The bloom was later when a more continental atmospheric flow from the east was detected. At Helgoland Roads, it seems that under turbid water conditions (= low light) zooplankton grazing can affect the timing of the phytoplankton bloom negatively. Warmer water temperatures will facilitate this. Under clear water conditions, light will be the main governing factor with regard to the timing of the spring bloom. These different water conditions are shown here to be mainly related to large-scale weather patterns. We found that the mean diatom bloom could be predicted from the sea level pressure one to three months in advance. Using historical pressure data, we derived a proxy for the timing of the spring bloom over the last centuries, showing an increased number of late (proxy-) blooms during the eighteenth century when the climate was considerably colder than today. We argue that these variations are important for the interpretation of inter-annual to centennial variations of biological processes. This is of particular interest when considering future scenarios, as well to considerations on past and future effects on the primary production and food webs.

Current-oriented swimming by jellyfish and its role in bloom maintenance.

Science.gov (United States)

Fossette, Sabrina; Gleiss, Adrian Christopher; Chalumeau, Julien; Bastian, Thomas; Armstrong, Claire Denise; Vandenabeele, Sylvie; Karpytchev, Mikhail; Hays, Graeme Clive

2015-02-02

Cross-flows (winds or currents) affect animal movements [1-3]. Animals can temporarily be carried off course or permanently carried away from their preferred habitat by drift depending on their own traveling speed in relation to that of the flow [1]. Animals able to only weakly fly or swim will be the most impacted (e.g., [4]). To circumvent this problem, animals must be able to detect the effects of flow on their movements and respond to it [1, 2]. Here, we show that a weakly swimming organism, the jellyfish Rhizostoma octopus, can orientate its movements with respect to currents and that this behavior is key to the maintenance of blooms and essential to reduce the probability of stranding. We combined in situ observations with first-time deployment of accelerometers on free-ranging jellyfish and simulated the behavior observed in wild jellyfish within a high-resolution hydrodynamic model. Our results show that jellyfish can actively swim countercurrent in response to current drift, leading to significant life-history benefits, i.e., increased chance of survival and facilitated bloom formation. Current-oriented swimming may be achieved by jellyfish either directly detecting current shear across their body surface [5] or indirectly assessing drift direction using other cues (e.g., magnetic, infrasound). Our coupled behavioral-hydrodynamic model provides new evidence that current-oriented swimming contributes to jellyfish being able to form aggregations of hundreds to millions of individuals for up to several months, which may have substantial ecosystem and socioeconomic consequences [6, 7]. It also contributes to improve predictions of jellyfish blooms' magnitude and movements in coastal waters. Copyright © 2015 Elsevier Ltd. All rights reserved.

Bloom's Taxonomy: Improving Assessment and Teaching-Learning Process

Science.gov (United States)

Chandio, Muhammad Tufail; Pandhiani, Saima Murtaza; Iqbal, Rabia

2016-01-01

This research study critically analyzes the scope and contribution of Bloom's Taxonomy in both assessment and teaching-learning process. Bloom's Taxonomy consists of six stages, namely; remembering, understanding, applying, analyzing, evaluating and creating and moves from lower degree to the higher degree. The study applies Bloom's Taxonomy to…

Bloom dynamics of the genus Pseudo-nitzschia (Bacillariophyceae in two coastal bays (NW Mediterranean Sea

Directory of Open Access Journals (Sweden)

Sonia Quijano-Scheggia

2008-09-01

Full Text Available The spatial and temporal variations in the composition of Pseudo-nitzschia during bloom events from August 2005 to February 2006 were characterised in two bays of the NW Mediterranean Sea (Alfacs and Fangar Bay by means of scanning electron microscopy (SEM. The study provides detailed records of the Pseudo-nitzschia community at the species level and describes its relationship with both the surrounding environmental conditions and biotic factors such as the accompanying phytoplankton community. The size distributions of several species of Pseudo-nitzschia were monitored during the bloom events. These measurements may serve as indicators of the physiological status of the cells. The species observed in the two bays were Pseudo-nitzschia calliantha, P. delicatissima, P. fraudulenta, P. multistriata, and P. pungens. In Alfacs Bay, a mixed species bloom of P. calliantha and P. delicatissima began in late August 2005 and lasted 11 weeks. In Fangar Bay, the Pseudo-nitzschia bloom was limited to the period from early August to late September 2005 and comprised P. calliantha and P. delicatissima. Commonly, the proliferation of Pseudo-nitzschia was mono-specific or was accompanied by other diatoms. Two objectively defined groups were identified by the statistical analysis in Alfacs bay; the first was made up only of winter samples and the second of summer and autumn samples. The first group was defined by a high concentration of NO3¯ and low concentrations of NH4+, conditions associated with a high abundance of P. delicatissima and a low abundance of P. calliantha. The second group expressed the opposite characteristics. A succession of different blooming species of Pseudo-nitzschia lasting months in Alfacs Bay is described.

A major seasonal phytoplankton bloom in the Madagascar Basin

Science.gov (United States)

Longhurst, Alan

2001-11-01

A hitherto-unnoticed phytoplankton bloom, of dimension 3000×1500 km, occupies the Madagascar Basin in late austral summer, being a prominent feature in SeaWiFS images. A first-order interpretation of the bloom mechanism invokes the seasonal deepening of the mixed layer within a strong mesoscale eddy-field and the consequent entrainment of nutrients into the photic zone. Features of the bloom correspond closely and appropriately with features of the eddy-field as observed by TOPEX-POSEIDON sea level anomalies. The bloom failed to develop in 1998, the second year of a two-year ENSO episode, when anomalously weak Southeast Trades will have failed to deepen the mixed layer as in other years.

Distance Sensitive Bloom Filters Without False Negatives

DEFF Research Database (Denmark)

Goswami, Mayank; Pagh, Rasmus; Silvestri, Francesco

2017-01-01

A Bloom filter is a widely used data-structure for representing a set S and answering queries of the form “Is x in S?”. By allowing some false positive answers (saying ‘yes’ when the answer is in fact ‘no’) Bloom filters use space significantly below what is required for storing S. In the distanc...

Harmful Freshwater Algal Blooms, With an Emphasis on Cyanobacteria

Directory of Open Access Journals (Sweden)

Hans W. Paerl

2001-01-01

Full Text Available Suspended algae, or phytoplankton, are the prime source of organic matter supporting food webs in freshwater ecosystems. Phytoplankton productivity is reliant on adequate nutrient supplies; however, increasing rates of nutrient supply, much of it manmade, fuels accelerating primary production or eutrophication. An obvious and problematic symptom of eutrophication is rapid growth and accumulations of phytoplankton, leading to discoloration of affected waters. These events are termed blooms. Blooms are a prime agent of water quality deterioration, including foul odors and tastes, deoxygenation of bottom waters (hypoxia and anoxia, toxicity, fish kills, and food web alterations. Toxins produced by blooms can adversely affect animal (including human health in waters used for recreational and drinking purposes. Numerous freshwater genera within the diverse phyla comprising the phytoplankton are capable of forming blooms; however, the blue-green algae (or cyanobacteria are the most notorious bloom formers. This is especially true for harmful toxic, surface-dwelling, scum-forming genera (e.g., Anabaena, Aphanizomenon, Nodularia, Microcystis and some subsurface bloom-formers (Cylindrospermopsis, Oscillatoria that are adept at exploiting nutrient-enriched conditions. They thrive in highly productive waters by being able to rapidly migrate between radiance-rich surface waters and nutrient-rich bottom waters. Furthermore, many harmful species are tolerant of extreme environmental conditions, including very high light levels, high temperatures, various degrees of desiccation, and periodic nutrient deprivation. Some of the most noxious cyanobacterial bloom genera (e.g., Anabaena, Aphanizomenon, Cylindrospermopsis, Nodularia are capable of fixing atmospheric nitrogen (N2, enabling them to periodically dominate under nitrogen-limited conditions. Cyanobacteria produce a range of organic compounds, including those that are toxic to higher-ranked consumers, from

Remote sensing of cyanobacteria-dominant algal blooms and water quality parameters in Zeekoevlei, a small hypertrophic lake, using MERIS

CSIR Research Space (South Africa)

Matthews, MW

2010-09-01

Full Text Available Eutrophication and cyanobacterial algal blooms present an increasing threat to the health of freshwater ecosystems and to humans who use these resources for drinking and recreation. Remote sensing is being used increasingly as a tool for monitoring...

GLRT Based Anomaly Detection for Sensor Network Monitoring

KAUST Repository

Harrou, Fouzi

2015-12-07

Proper operation of antenna arrays requires continuously monitoring their performances. When a fault occurs in an antenna array, the radiation pattern changes and can significantly deviate from the desired design performance specifications. In this paper, the problem of fault detection in linear antenna arrays is addressed within a statistical framework. Specifically, a statistical fault detection method based on the generalized likelihood ratio (GLR) principle is utilized for detecting potential faults in linear antenna arrays. The proposed method relies on detecting deviations in the radiation pattern of the monitored array with respect to a reference (fault-free) one. To assess the abilities of the GLR based fault detection method, three case studies involving different types of faults have been performed. The simulation results clearly illustrate the effectiveness of the GLR-based fault detection method in monitoring the performance of linear antenna arrays.

GLRT Based Anomaly Detection for Sensor Network Monitoring

KAUST Repository

Harrou, Fouzi; Sun, Ying

2015-01-01

Proper operation of antenna arrays requires continuously monitoring their performances. When a fault occurs in an antenna array, the radiation pattern changes and can significantly deviate from the desired design performance specifications. In this paper, the problem of fault detection in linear antenna arrays is addressed within a statistical framework. Specifically, a statistical fault detection method based on the generalized likelihood ratio (GLR) principle is utilized for detecting potential faults in linear antenna arrays. The proposed method relies on detecting deviations in the radiation pattern of the monitored array with respect to a reference (fault-free) one. To assess the abilities of the GLR based fault detection method, three case studies involving different types of faults have been performed. The simulation results clearly illustrate the effectiveness of the GLR-based fault detection method in monitoring the performance of linear antenna arrays.

Eddy-driven stratification initiates North Atlantic spring phytoplankton blooms.

Science.gov (United States)

Mahadevan, Amala; D'Asaro, Eric; Lee, Craig; Perry, Mary Jane

2012-07-06

Springtime phytoplankton blooms photosynthetically fix carbon and export it from the surface ocean at globally important rates. These blooms are triggered by increased light exposure of the phytoplankton due to both seasonal light increase and the development of a near-surface vertical density gradient (stratification) that inhibits vertical mixing of the phytoplankton. Classically and in current climate models, that stratification is ascribed to a springtime warming of the sea surface. Here, using observations from the subpolar North Atlantic and a three-dimensional biophysical model, we show that the initial stratification and resulting bloom are instead caused by eddy-driven slumping of the basin-scale north-south density gradient, resulting in a patchy bloom beginning 20 to 30 days earlier than would occur by warming.

Understanding the Effect of Stratification on Vertical and Temporal Heterogenieties of Cyanobacteria Blooms in Lakes Using a Long Term in-situ Monitoring Station

Science.gov (United States)

Wilkinson, A.; Guala, M.; Hondzo, M.

2017-12-01

Harmful Algal Blooms (HAB) are made up of potentially toxic freshwater microorganisms called cyanobacteria, because of this they are a ecological and public health hazard. The occurrences of toxic HAB are unpredictable and highly spatially and temporary variable in freshwater ecosystems. To study the abiotic drivers for toxic HAB, a floating research station has been deployed in a hyper-eutrophic lake in Madison Lake, Minnesota, from June-October 2016. This research station provides full depth water quality (hourly) and meteorological monitoring (5 minutes). Water quality monitoring is performed by an autonomously traversed water quality sonde that provides chemical, physical and biological measurements; including phycocyanin, a photosynthetic pigment distinct to cyanobacteria. A bloom of cyanobacteria recorded in the epiliminion in mid-July was driven by prolonged strong thermal stratification in the water column, high surface water temperatures and high phosphate concentrations in the epiliminion. The high biovolume (BV) persisted until late September and was sustained below the surface after stratification weakened, when the thermocline did not confine cyanobacteria-rich layers any more, and cyanobacteria vertical heterogeneities decayed in the water column. High correlations among BV stratification, surface water temperature, and stratification stability informed the development of a quantitative relationship to determine how BV heterogeneities vary with thermal structure in the water column. The BV heterogeneity decreased with thermal stratification stability and surface water temperature, and the dynamic lake stability described by the Lake Number. Finally the location of maximum BV accumulation showed diurnal patterns ie. BV peaks were observed at 1 m depth during the day and deeper layers during the night, which followed patterns in light penetration and thermocline depth. These findings capture cyanobacteria vertical and temporal heterogeneities on a on

Climate Change and Algal Blooms =

Science.gov (United States)

Lin, Shengpan

Algal blooms are new emerging hazards that have had important social impacts in recent years. However, it was not very clear whether future climate change causing warming waters and stronger storm events would exacerbate the algal bloom problem. The goal of this dissertation was to evaluate the sensitivity of algal biomass to climate change in the continental United States. Long-term large-scale observations of algal biomass in inland lakes are challenging, but are necessary to relate climate change to algal blooms. To get observations at this scale, this dissertation applied machine-learning algorithms including boosted regression trees (BRT) in remote sensing of chlorophyll-a with Landsat TM/ETM+. The results show that the BRT algorithm improved model accuracy by 15%, compared to traditional linear regression. The remote sensing model explained 46% of the total variance of the ground-measured chlorophyll- a in the first National Lake Assessment conducted by the US Environmental Protection Agency. That accuracy was ecologically meaningful to study climate change impacts on algal blooms. Moreover, the BRT algorithm for chlorophyll- a would not have systematic bias that is introduced by sediments and colored dissolved organic matter, both of which might change concurrently with climate change and algal blooms. This dissertation shows that the existing atmospheric corrections for Landsat TM/ETM+ imagery might not be good enough to improve the remote sensing of chlorophyll-a in inland lakes. After deriving long-term algal biomass estimates from Landsat TM/ETM+, time series analysis was used to study the relations of climate change and algal biomass in four Missouri reservoirs. The results show that neither temperature nor precipitation was the only factor that controlled temporal variation of algal biomass. Different reservoirs, even different zones within the same reservoir, responded differently to temperature and precipitation changes. These findings were further

Rethinking Bloom's Taxonomy: Implications for Testing and Assessment.

Science.gov (United States)

Anderson, Lorin W.

This paper describes a work in progress on a second edition of "Taxonomy of Educational Objectives, The Classification of Educational Goals, Handbook I: Cognitive Domain," also known as "Bloom's Taxonomy" (B. Bloom and others, Eds., 1956). The new edition will be grounded in the collective wisdom of the original…

Harmful algal bloom smart device application: using image analysis and machine learning techniques for early classification of harmful algal blooms (SETAC presentation)

Science.gov (United States)

Reports of toxic cyanobacterial blooms, also known as Harmful Algal Blooms (HABS) have increased drastically in recent years. HABS impact human health from causing mild allergies to liver damage and death. The Ecological Stewardship Institute (ESI) at Northern Kentucky Universi...

Tropical cyanobacterial blooms: a review of prevalence, problem taxa, toxins and influencing environmental factors

Directory of Open Access Journals (Sweden)

Maxine A.D. Mowe

2014-12-01

Full Text Available Toxic cyanobacterial blooms are a major issue in freshwater systems in many countries. The potentially toxic species and their ecological causes are likely to be different in tropical zones from those in temperate water bodies; however, studies on tropical toxic cyanobacterial blooms are sporadic and currently there is no global synthesis. In this review, we examined published information on tropical cyanobacterial bloom occurrence and toxin production to investigate patterns in their growth and distribution. Microcystis was the most frequently occurring bloom genus throughout tropical Asia, Africa and Central America, while Cylindrospermopsis and Anabaena blooms occurred in various locations in tropical Australia, America and Africa. Microcystis blooms were more prevalent during the wet season while Cylindrospermopsis blooms were more prevalent during the dry period. Microcystin was the most encountered toxin throughout the tropics. A meta-analysis of tropical cyanobacterial blooms showed that Microcystis blooms were more associated with higher total nitrogen concentrations, while Cylindrospermopsis blooms were more associated with higher maximum temperatures. Meta-analysis also showed a positive linear relationship between levels of microcystin and N:P (nitrate:phosphate ratio. Tropical African Microcystis blooms were found to have the lowest microcystin levels in relation to biomass and N:P (nitrate:phosphate compared to tropical Asian, Australian and American blooms. There was also no significant correlation between microcystin concentration and cell concentration for tropical African blooms as opposed to tropical Asian and American blooms. Our review illustrates that some cyanobacteria and toxins are more prevalent in tropical areas. While some tropical countries have considerable information regarding toxic blooms, others have few or no reported studies. 

Hydrodynamic control of microphytoplankton bloom in a coastal sea

Indian Academy of Sciences (India)

Hydrodynamic control of microphytoplankton bloom in a coastal sea ... many times more than what could be accounted for by solar insolation and nutrient levels. ... and stable water column and weak winds left undisturbed, the transient bloom.

Identification of non-indigenous phytoplankton species dominated bloom off Goa using inverted microscopy and pigment (HPLC) analysis

Science.gov (United States)

Bhaskar, P. V.; Roy, Rajdeep; Gauns, Mangesh; Shenoy, D. M.; Rao, V. D.; Mochemadkar, S.

2011-12-01

An unusual phytoplankton bloom dominated by unidentified green coloured spherical algal cells (˜5μm diameter) and dinoflagellates ( Heterocapsa, Scripsiella and Gymnodinium) was encountered along the coast of Goa, India during 27 and 29 January, 2005. Pigment analysis was carried out using both fluorometric and HPLC methods. Seawater samples collected from various depths within the intense bloom area showed high concentrations of Chl a (up to 106 mg m - 3) associated with low bacterial production (0.31 to 0.52 mg C m - 3 h - 1) and mesozooplankton biomass (0.03 ml m - 3). Pigment analyses of the seawater samples were done using HPLC detected marker pigments corresponding to prasinophytes, dinoflagellates and diatoms. Chlorophyll b (36-56%) followed by peridinin (15-30%), prasinoxanthin (11-17%) and fucoxanthin (7-15%) were the major diagnostic pigments while pigments of cryptophytes and cyanobacteria including alloxanthin and zeaxanthin formed <10%. Although microscopic analysis indicated a decline in the bloom, pheaophytin concentrations in the water column measured by both techniques were very low, presumably due to fast recycling and/or settling rate. The unique composition of the bloom and its probable causes are discussed in this paper.

An Artificial Neural Network Based Short-term Dynamic Prediction of Algae Bloom

Directory of Open Access Journals (Sweden)

Yao Junyang

2014-06-01

Full Text Available This paper proposes a method of short-term prediction of algae bloom based on artificial neural network. Firstly, principal component analysis is applied to water environmental factors in algae bloom raceway ponds to get main factors that influence the formation of algae blooms. Then, a model of short-term dynamic prediction based on neural network is built with the current chlorophyll_a values as input and the chlorophyll_a values in the next moment as output to realize short-term dynamic prediction of algae bloom. Simulation results show that the model can realize short-term prediction of algae bloom effectively.

Consortial brown tide - picocyanobacteria blooms in Guantánamo Bay, Cuba.

Science.gov (United States)

Hall, Nathan S; Litaker, R Wayne; Kenworthy, W Judson; Vandersea, Mark W; Sunda, William G; Reid, James P; Slone, Daniel H; Butler, Susan

2018-03-01

A brown tide bloom of Aureoumbra lagunensis developed in Guantánamo Bay, Cuba during a period of drought in 2013 that followed heavy winds and rainfall from Hurricane Sandy in late October 2012. Based on satellite images and water turbidity measurements, the bloom appeared to initiate in January 2013. The causative species (A. lagunensis) was confirmed by microscopic observation, and pigment and genetic analyses of bloom samples collected on May 28 of that year. During that time, A. lagunensis reached concentrations of 900,000 cells ml -1 (28 ppm by biovolume) in the middle portion of the Bay. Samples could not be collected from the northern (Cuban) half of the Bay because of political considerations. Subsequent sampling of the southern half of the Bay in November 2013, April 2014, and October 2014 showed persistent lower concentrations of A. lagunensis, with dominance shifting to the cyanobacterium Synechococcus (up to 33 ppm in April), an algal group that comprised a minor bloom component on May 28. Thus, unlike the brown tide bloom in Laguna Madre, which lasted 8 years, the bloom in Guantánamo Bay was short-lived, much like recent blooms in the Indian River, Florida. Although hypersaline conditions have been linked to brown tide development in the lagoons of Texas and Florida, observed euhaline conditions in Guantánamo Bay (salinity 35-36) indicate that strong hypersalinity is not a requirement for A. lagunensis bloom formation. Microzooplankton biomass dominated by ciliates was high during the observed peak of the brown tide, and ciliate abundance was high compared to other systems not impacted by brown tide. Preferential grazing by zooplankton on non-brown tide species, as shown in A. lagunensis blooms in Texas and Florida, may have been a factor in the development of the Cuban brown tide bloom. However, subsequent selection of microzooplankton capable of utilizing A. lagunensis as a primary food source may have contributed to the short-lived duration

Computerized flow monitors detect small kicks

Energy Technology Data Exchange (ETDEWEB)

McCann, D.; White, D. (Sedco Forex, Paris (FR))

1992-02-24

This paper reports on a smart alarm system installed on a number of offshore rigs and one land rig which can detect kicks more quickly than conventional systems. This rapid kick detection improves rig safety because the smaller the detected influx, the easier it is to control the well. The extensive computerized monitoring system helps drilling personnel detect fluid influxes and fluid losses before the changes in flow would normally be apparent.

Further Studies on the Physical and Biogeochemical Causes for Large Interannual Changes in the Patagonian Shelf Spring-Summer Phytoplankton Bloom Biomass

Science.gov (United States)

Signorini, Sergio R.; Garcia, Virginia M.T.; Piola, Alberto R.; Evangelista, Heitor; McClain, Charles R.; Garcia, Carlos A.E.; Mata, Mauricio M.

2009-01-01

A very strong and persistent phytoplankton bloom was observed by ocean color satellites during September - December 2003 along the northern Patagonian shelf. The 2003 bloom had the highest extent and chlorophyll a (Chl-a) concentrations of the entire Sea-viewing Wide Field-of-view Sensor (SeaWiFS) period (1997 to present). SeaWiFS-derived Chl-a exceeded 20 mg/cu m in November at the bloom center. The bloom was most extensive in December when it spanned more than 300 km across the shelf and nearly 900 km north-south (35degS to 43degS). The northward reach and the deep penetration on the shelf of the 2003 bloom were quite anomalous when compared with other years, which showed the bloom more confined to the Patagonian shelf break (PSB). The PSB bloom is a conspicuous austral spring-summer feature detected by ocean color satellites and its timing can be explained using the Sverdrup critical depth theory. Based on high-resolution numerical simulations, in situ and remote sensing data, we provide some suggestions for the probable mechanisms responsible for that large interannual change of biomass as seen by ocean color satellites. Potential sources of macro and micro (e.g., Fe) nutrients that sustain the high phytoplankton productivity of the Patagonian shelf waters are identified, and the most likely physical processes that maintain the nutrient balance in the region are discussed.

Nitrogen utilization during spring phytoplankton bloom development in the southeast Bering Sea

International Nuclear Information System (INIS)

Sambrotto, R.N.

1983-01-01

Interactions beween a high latitude, continental shelf, spring phytoplankton bloom and water column physics and chemistry were studied using 15 N measured rates of nitrogen uptake. Peak bloom conditions commenced when the mixed layer shallowed and minimized respirational losses. Integrative light-mixing growth models were accurate during early bloom stages. An advection-diffusion model associated peak bloom nitrate uptake with pycnocline mixing rates of 2.1 m d -1 in an 18 m mixed layer. Maximum nitrogen specific uptake rates (hr -1 ), unlike those of carbon, coincided with peak bloom conditions. Although species compositions among peak bloom periods were similar, particulate C/N ratios were not. Apparently, both intercellular factors and prevailing mixing conditions influence specific uptake rates and cell composition. A large proportion of new (nitrate) to total productivity was associated with the dominance of the early bloom forming diatoms in the mixed layer. In the absence of these net plankton the residual nanoplankton dominated community exhibited a greater dependence on regenerated nitrogen. Nitrate uptake averaged 700 mg-at m -2 during the spring bloom and 1 g-at m -2 year -1 . The yearly f factor was 0.40. Nitrogen uptake based carbon productivity was 188 g C m -2 year -1

The plankton community on Sukkertop and Fylla Banks off West Greenland during a spring bloom and post-bloom period: Hydrography, phytoplankton and protozooplankton

DEFF Research Database (Denmark)

Poulsen, Louise K.; Reuss, N.

2002-01-01

The plankton community structure was investigated on Sukkertop and Fylla Banks off West Greenland during the spring bloom in May 2000 and the post-bloom period in June 1999. In May a small change in density, clearly illustrated by the profile of potential energy, was sufficient to support a spring...... the phytoplankton community. Heterotrophic biomass was low (5 +/- 1 mg C m(-3)) and an important part was comprised by heterotrophic nanoflagellates (24 +/- 1%). Protozooplankters (heterotrophic dinoflagellates and ciliates) were important grazers of the phytoplankton community in the post-bloom period (estimated...

A review of carbon blooms on JET and TFTR

International Nuclear Information System (INIS)

Ulrickson, M.

1990-01-01

Operation of JET and TFTR at high auxiliary heating power has resulted in the occurrence of phenomena called carbon blooms. The carbon bloom is characterized by a rapid increases in the emission of carbon spectral lines, the Z eff , the radiated power, and the plasma density. There is also a concurrent decrease in the neutron emission rate, stored energy, and plasma pressure. On both machines the source of the carbon is observed to be at localized (both toroidally and polidally) hot spots on either the divertor plates or limiters. The localized hot spots are due to one or more of the following: disruption damage spots, misalignment of tiles, and/or exposed edges of tiles. The occurrence of carbon blooms limits the performance of the highest input power plasmas on both machines. This paper reviews the carbon bloom phenomenon as it occurs on both JET and TFTR. (orig.)

Health risk assessment standards of cyanobacteria bloom occurrence in bathing sites

Directory of Open Access Journals (Sweden)

Agnieszka Stankiewicz

2011-03-01

Full Text Available Threat for human health appears during a massive cyanobacteria bloom in potable water used for human consumption or in basins used for recreational purposes. General health risk assessment standards and preventive measures to be taken by sanitation service were presented in scope of: – evaluation of cyanobacteria bloom occurrence in bathing sites / water bodies, – procedures in case of cyanobacteria bloom, including health risk assessment and decision making process to protect users’ health at bathing sites, – preventive measures, to be taken in case of cyanobacteria bloom occurrence in bathing sites and basins, where bathing sites are located.

Phytoplankton bloom and subpolar gyre induced dynamics in the North Atlantic

DEFF Research Database (Denmark)

Ferreira, Ana Sofia; Hátún, H.; Counillon, F.

Several hypotheses have been promoted for phytoplankton bloom onset in the North Atlantic. First we show that the bloom dynamics in the northeastern corner stand out from the rest of the subpolar Atlantic, and thus warrants focused attention. We hypothesized that, for this region, late and weak...... blooms are expected in years of a strong subpolar gyre, i.e. strong atmospheric forcing, and cold and low saline conditions. We apply novel phenology algorithms to satellite ocean colour data, and analyse the outcome together with the subpolar gyre index. We find that the relationship between the bloom...

Peculiarities of the Woody Plants Re-Bloom

OpenAIRE

Opalko Olga Anatolievna; Opalko Anatoly Ivanovich

2015-01-01

The data of literary sources concerning the bloom of angiosperm plants and deviation in the development of a flower and inflorescence, in particular untimely flowering, was generalized; our observation results of some peculiarities of re-bloom of woody plants in the National Dendrological Park “Sofiyivka” of NAS of Ukraine (NDP “Sofiyivka”) were discussed. The flowering process was formed during a long-term evolution of a propagation system of angiosperm plants as a basis of fertilization and...

Georges Bank: a leaky incubator of Alexandrium fundyense blooms.

Science.gov (United States)

McGillicuddy, D J; Townsend, D W; Keafer, B A; Thomas, M A; Anderson, D M

2014-05-01

A series of oceanographic surveys on Georges Bank document variability of populations of the toxic dinoflagellate Alexandrium fundyense on time scales ranging from synoptic to seasonal to interannual. Blooms of A. fundyense on Georges Bank can reach concentrations on the order of 10 4 cells l -1 , and are generally bank-wide in extent. Georges Bank populations of A. fundyense appear to be quasi-independent of those in the adjacent coastal Gulf of Maine, insofar as they occupy a hydrographic niche that is colder and saltier than their coastal counterparts. In contrast to coastal populations that rely on abundant resting cysts for bloom initiation, very few cysts are present in the sediments on Georges Bank. Bloom dynamics must therefore be largely controlled by the balance between growth and mortality processes, which are at present largely unknown for this population. Based on correlations between cell abundance and nutrient distributions, ammonium appears to be an important source of nitrogen for A. fundyense blooms on Georges Bank.

Characterisation of transparent exopolymer particles (TEP) produced during algal bloom: A membrane treatment perspective

KAUST Repository

Villacorte, Loreen O.

2013-01-01

Algal blooms are currently a major concern of the membrane industry as it generates massive concentrations of organic matter (e.g. transparent exopolymer particles [TEP]), which can adversely affect the operation of membrane filtration systems. The goal of this study is to understand the production, composition and membrane rejection of these organic materials using different characterisation techniques. Two common species of bloom-forming freshwater and marine algae were cultivated in batch cultures for 30days and the productions of TEP and other organic matter were monitored at different growth phases. TEP production of the marine diatom, Chaetoceros affinis, produced 6-9 times more TEP than the freshwater blue-green algae, Microcystis. The organic substances produced by both algal species were dominated by biopolymeric substances such as polysaccharides (45-64%) and proteins (2-17%) while the remaining fraction comprises of low molecular weight refractory (humic-like) and/ or biogenic organic substances. MF/UF membranes mainly rejected the biopolymers but not the low molecular weight organic materials. MF membranes (0.1-0.4 lm) rejected 42-56% of biopolymers, while UF membranes (10-100 kDa) rejected 65-95% of these materials. Further analysis of rejected organic materials on the surface of the membranes revealed that polysac-charides and proteins are likely responsible for the fouling of MF/UF systems during an algal bloom situation. © 2013 Desalination Publications.

Peran Pt.bloom Agro Dalam Implementasi Prinsip Fair Trade Di Indonesia (Studi Kasus: Ekspor Beras Organik Pt.bloom Agro Ke Mancanegara Tahun 2008-2015)

OpenAIRE

Yealta, Den; Ikhsani, Munadia

2016-01-01

This research describes the role of PT.Bloom Agro to do Fair Teade implementation in Indonesia in the case study is the export of PT.Bloom Agros€™s organic rice to foreign country. Fair Trade is the kind of Alternatives trade which populer as donatian movement in 1940. But now in the globalitation era that causes of free trade, fair trade is more popular as alternatives trade movement and as a certification to mark a product has fair tarde guarantee. And in Indonesia PT.Bloom Agro which an ex...

Low-complexity R-peak detection for ambulatory fetal monitoring

International Nuclear Information System (INIS)

Rooijakkers, Michael J; Rabotti, Chiara; Mischi, Massimo; Oei, S Guid

2012-01-01

Non-invasive fetal health monitoring during pregnancy is becoming increasingly important because of the increasing number of high-risk pregnancies. Despite recent advances in signal-processing technology, which have enabled fetal monitoring during pregnancy using abdominal electrocardiogram (ECG) recordings, ubiquitous fetal health monitoring is still unfeasible due to the computational complexity of noise-robust solutions. In this paper, an ECG R-peak detection algorithm for ambulatory R-peak detection is proposed, as part of a fetal ECG detection algorithm. The proposed algorithm is optimized to reduce computational complexity, without reducing the R-peak detection performance compared to the existing R-peak detection schemes. Validation of the algorithm is performed on three manually annotated datasets. With a detection error rate of 0.23%, 1.32% and 9.42% on the MIT/BIH Arrhythmia and in-house maternal and fetal databases, respectively, the detection rate of the proposed algorithm is comparable to the best state-of-the-art algorithms, at a reduced computational complexity. (paper)

Low-complexity R-peak detection for ambulatory fetal monitoring.

Science.gov (United States)

Rooijakkers, Michael J; Rabotti, Chiara; Oei, S Guid; Mischi, Massimo

2012-07-01

Non-invasive fetal health monitoring during pregnancy is becoming increasingly important because of the increasing number of high-risk pregnancies. Despite recent advances in signal-processing technology, which have enabled fetal monitoring during pregnancy using abdominal electrocardiogram (ECG) recordings, ubiquitous fetal health monitoring is still unfeasible due to the computational complexity of noise-robust solutions. In this paper, an ECG R-peak detection algorithm for ambulatory R-peak detection is proposed, as part of a fetal ECG detection algorithm. The proposed algorithm is optimized to reduce computational complexity, without reducing the R-peak detection performance compared to the existing R-peak detection schemes. Validation of the algorithm is performed on three manually annotated datasets. With a detection error rate of 0.23%, 1.32% and 9.42% on the MIT/BIH Arrhythmia and in-house maternal and fetal databases, respectively, the detection rate of the proposed algorithm is comparable to the best state-of-the-art algorithms, at a reduced computational complexity.

A Partially Distributed Intrusion Detection System for Wireless Sensor Networks

Directory of Open Access Journals (Sweden)

Eung Jun Cho

2013-11-01

Full Text Available The increasing use of wireless sensor networks, which normally comprise several very small sensor nodes, makes their security an increasingly important issue. They can be practically and efficiently secured using intrusion detection systems. Conventional security mechanisms are not usually applicable due to the sensor nodes having limitations of computational power, memory capacity, and battery power. Therefore, specific security systems should be designed to function under constraints of energy or memory. A partially distributed intrusion detection system with low memory and power demands is proposed here. It employs a Bloom filter, which allows reduced signature code size. Multiple Bloom filters can be combined to reduce the signature code for each Bloom filter array. The mechanism could then cope with potential denial of service attacks, unlike many previous detection systems with Bloom filters. The mechanism was evaluated and validated through analysis and simulation.

Algal Bloom: Boon or Bane?

Digital Repository Service at National Institute of Oceanography (India)

LokaBharathi, P.A.

Algal blooms occur in response to nutrient deplete or replete conditions. Nitrogen fixing forms proliferate under oligotrophic conditions when nutrient levels are low. Replete conditions in response to upwelling creates the most biologically...

Blooming Trees: Substructures and Surrounding Groups of Galaxy Clusters

Science.gov (United States)

Yu, Heng; Diaferio, Antonaldo; Serra, Ana Laura; Baldi, Marco

2018-06-01

We develop the Blooming Tree Algorithm, a new technique that uses spectroscopic redshift data alone to identify the substructures and the surrounding groups of galaxy clusters, along with their member galaxies. Based on the estimated binding energy of galaxy pairs, the algorithm builds a binary tree that hierarchically arranges all of the galaxies in the field of view. The algorithm searches for buds, corresponding to gravitational potential minima on the binary tree branches; for each bud, the algorithm combines the number of galaxies, their velocity dispersion, and their average pairwise distance into a parameter that discriminates between the buds that do not correspond to any substructure or group, and thus eventually die, and the buds that correspond to substructures and groups, and thus bloom into the identified structures. We test our new algorithm with a sample of 300 mock redshift surveys of clusters in different dynamical states; the clusters are extracted from a large cosmological N-body simulation of a ΛCDM model. We limit our analysis to substructures and surrounding groups identified in the simulation with mass larger than 1013 h ‑1 M ⊙. With mock redshift surveys with 200 galaxies within 6 h ‑1 Mpc from the cluster center, the technique recovers 80% of the real substructures and 60% of the surrounding groups; in 57% of the identified structures, at least 60% of the member galaxies of the substructures and groups belong to the same real structure. These results improve by roughly a factor of two the performance of the best substructure identification algorithm currently available, the σ plateau algorithm, and suggest that our Blooming Tree Algorithm can be an invaluable tool for detecting substructures of galaxy clusters and investigating their complex dynamics.

Consortial brown tide − picocyanobacteria blooms in Guantánamo Bay, Cuba

Science.gov (United States)

Hall, Nathan S; Litaker, R. Wayne; Kenworthy, W. Judson; Vandersea, Mark W.; Sunda, William G.; Reid, James P.; Slone, Daniel H.; Butler, Susan M.

2018-01-01

A brown tide bloom of Aureoumbra lagunensis developed in Guantánamo Bay, Cuba during a period of drought in 2013 that followed heavy winds and rainfall from Hurricane Sandy in late October 2012. Based on satellite images and water turbidity measurements, the bloom appeared to initiate in January 2013. The causative species (A. lagunensis) was confirmed by microscopic observation, and pigment and genetic analyses of bloom samples collected on May 28 of that year. During that time, A. lagunensis reached concentrations of 900,000 cells ml−1 (28 ppm by biovolume) in the middle portion of the Bay. Samples could not be collected from the northern (Cuban) half of the Bay because of political considerations. Subsequent sampling of the southern half of the Bay in November 2013, April 2014, and October 2014 showed persistent lower concentrations of A. lagunensis, with dominance shifting to the cyanobacterium Synechococcus (up to 33 ppm in April), an algal group that comprised a minor bloom component on May 28. Thus, unlike the brown tide bloom in Laguna Madre, which lasted 8 years, the bloom in Guantánamo Bay was short-lived, much like recent blooms in the Indian River, Florida. Although hypersaline conditions have been linked to brown tide development in the lagoons of Texas and Florida, observed euhaline conditions in Guantánamo Bay (salinity 35–36) indicate that strong hypersalinity is not a requirement for A. lagunensis bloom formation. Microzooplankton biomass dominated by ciliates was high during the observed peak of the brown tide, and ciliate abundance was high compared to other systems not impacted by brown tide. Preferential grazing by zooplankton on non-brown tide species, as shown in A. lagunensis blooms in Texas and Florida, may have been a factor in the development of the Cuban brown tide bloom. However, subsequent selection of microzooplankton capable of utilizing A. lagunensis as a primary food source may have contributed to the

Succession and fate of the spring diatom bloom in Disko Bay, western Greenland

DEFF Research Database (Denmark)

Dünweber, Michael; Swalethorp, Rasmus; Kjellerup, Sanne

2010-01-01

Phytoplankton and copepod succession was investigated in Disko Bay, western Greenland from February to July 2008. The spring phytoplankton bloom developed immediately after the breakup of sea ice and reached a peak concentration of 24 mg chl a m–3 2 wk later. The bloom was analyzed during 3 phases...... from the initiation of the bloom but only had a small grazing impact on the phytoplankton. Consequently, there was a close coupling between the spring phytoplankton bloom and sedimentation of particulate organic carbon (POC). Out of 1836 ± 180 mg C m–2 d–1 leaving the upper 50 m, 60% was phytoplankton...... and fate of the phytoplankton spring bloom was controlled by nitrogen limitation and subsequent sedimentation, while grazing-mediated flux by the Calanus-dominated copepod community played a minor role in the termination of the spring bloom of Disko Bay....

Algal blooms: an emerging threat to seawater reverse osmosis desalination

KAUST Repository

Villacorte, Loreen O.

2014-08-04

Seawater reverse osmosis (SWRO) desalination technology has been rapidly growing in terms of installed capacity and global application over the last decade. An emerging threat to SWRO application is the seasonal proliferation of microscopic algae in seawater known as algal blooms. Such blooms have caused operational problems in SWRO plants due to clogging and poor effluent quality of the pre-treatment system which eventually forced the shutdown of various desalination plants to avoid irreversible fouling of downstream SWRO membranes. This article summarizes the current state of SWRO technology and the emerging threat of algal blooms to its application. It also highlights the importance of studying the algal bloom phenomena in the perspective of seawater desalination, so proper mitigation and preventive strategies can be developed in the near future. © 2014 © 2014 Balaban Desalination Publications. All rights reserved.

Algal blooms: an emerging threat to seawater reverse osmosis desalination

KAUST Repository

Villacorte, Loreen O.; Tabatabai, S. Assiyeh Alizadeh; Dhakal, N.; Amy, Gary L.; Schippers, Jan Cornelis; Kennedy, Maria Dolores

2014-01-01

Seawater reverse osmosis (SWRO) desalination technology has been rapidly growing in terms of installed capacity and global application over the last decade. An emerging threat to SWRO application is the seasonal proliferation of microscopic algae in seawater known as algal blooms. Such blooms have caused operational problems in SWRO plants due to clogging and poor effluent quality of the pre-treatment system which eventually forced the shutdown of various desalination plants to avoid irreversible fouling of downstream SWRO membranes. This article summarizes the current state of SWRO technology and the emerging threat of algal blooms to its application. It also highlights the importance of studying the algal bloom phenomena in the perspective of seawater desalination, so proper mitigation and preventive strategies can be developed in the near future. © 2014 © 2014 Balaban Desalination Publications. All rights reserved.

Use of Bloom's Taxonomy in Developing Reading Comprehension Specifications

Science.gov (United States)

Luebke, Stephen; Lorie, James

2013-01-01

This article is a brief account of the use of Bloom's Taxonomy of Educational Objectives (Bloom, Engelhart, Furst, Hill, & Krathwohl, 1956) by staff of the Law School Admission Council in the 1990 development of redesigned specifications for the Reading Comprehension section of the Law School Admission Test. Summary item statistics for the…

Privacy-Preserving Electrocardiogram Monitoring for Intelligent Arrhythmia Detection.

Science.gov (United States)

Son, Junggab; Park, Juyoung; Oh, Heekuck; Bhuiyan, Md Zakirul Alam; Hur, Junbeom; Kang, Kyungtae

2017-06-12

Long-term electrocardiogram (ECG) monitoring, as a representative application of cyber-physical systems, facilitates the early detection of arrhythmia. A considerable number of previous studies has explored monitoring techniques and the automated analysis of sensing data. However, ensuring patient privacy or confidentiality has not been a primary concern in ECG monitoring. First, we propose an intelligent heart monitoring system, which involves a patient-worn ECG sensor (e.g., a smartphone) and a remote monitoring station, as well as a decision support server that interconnects these components. The decision support server analyzes the heart activity, using the Pan-Tompkins algorithm to detect heartbeats and a decision tree to classify them. Our system protects sensing data and user privacy, which is an essential attribute of dependability, by adopting signal scrambling and anonymous identity schemes. We also employ a public key cryptosystem to enable secure communication between the entities. Simulations using data from the MIT-BIH arrhythmia database demonstrate that our system achieves a 95.74% success rate in heartbeat detection and almost a 96.63% accuracy in heartbeat classification, while successfully preserving privacy and securing communications among the involved entities.

Importance of a winter dinoflagellate-microflagellate bloom in the Patuxent River estuary

Science.gov (United States)

Sellner, K. G.; Lacouture, R. V.; Cibik, S. J.; Brindley, A.; Brownlee, S. G.

1991-01-01

A dense bloom of Katodinium rotundatum was observed in the Patuxent River estuary from December to February 1989. The dinoflagellate dominated phytoplankton densities reaching 10 8 cells l -1 and contributed up to 1900 μgC l -1 in near-surface depths. The bloom maintained a distinct patch extending over 10-25 km of the estuary or approximately one-third to one-half of the total estuary (salinities from 5-13 ppt) and was restricted to regions immediately upriver of the transition between the shallow upriver (3-4 m) and deeper lower estuary (10 m). Daily measurements collected in the primary bloom area at the same time each day in the study area indicated 80- and 120-fold variations in chlorophyll and cell densities from day to day. Densities of potential grazers in the region were high with rotifers, primarily Synchaeta baltica, reaching densities of 1000 l -1 in early winter, and the copepod Eurytemora affinis reaching levels exceeding 1·15 × 10 5 m -3 in February. Estimates of grazing pressure by these planktonic herbivores indicated substantial grazing losses for the bloom, with up to 67% of bloom biomass consumed day -1 in February. Nutrient concentrations and ratios of N/P during the bloom suggested potentially N-limited conditions; bloom demise was coincident with a shift to high N/P ratios and high river flows. These data as well as other historical data suggest that dinoflagellate blooms in the lower Patuxent River estuary could be the primary source of carbon to the system during the winter and supply a large reservoir of labile organic matter to planktonic secondary producers prior to annual spring diatom blooms in the region.

OSU MODIS FLH Bloom Product

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Two bloom products were developed for the Oregon coast based on the observed change between running 8-day composite chlorophyll-a (CHL) and fluorescence line-height...

Potentially harmful microalgae and algal blooms in a eutrophic estuary in Turkey

Directory of Open Access Journals (Sweden)

S. TAS

2015-07-01

Full Text Available Distribution of potentially harmful microalgae and algal blooms were investigated at monthly and weekly time scales between October 2009 and September 2010 in the Golden Horn, a eutrophic estuary in the Sea of Marmara (Turkey. Several physical and chemical parameters were analysed together with phytoplankton composition and abundance. A total number of 23 potentially harmful and/or bloom-forming microalgae (14 dinoflagellates, 4 diatoms and 5 phytoflagellates were identified throughout this study period, of which nine taxa have been confirmed to be toxic elsewhere in the world. Most harmful species and algal blooms were observed in late spring and summer particularly in the middle and upper estuaries, and nine taxa formed dense and successive algal blooms causing water discoloration. Nutrient concentrations increased significantly from the lower to the upper estuary. Additionally, high organic matter loads in the upper estuary could also have benefited by mixotrophic species. The increasing number of potentially harmful and bloom-forming species and algal blooms indicated that the GHE is a potential risk area for future HABs.

Characteristics of picoplankton abundances during a Thalassiosira diporocyclus bloom in the Taiwan Bank in late winter.

Science.gov (United States)

Jiang, Xin; Li, Jiajun; Ke, Zhixin; Xiang, Chenhui; Tan, Yehui; Huang, Liangmin

2017-04-15

To understand the variations of picoplankton (Prochlorococcus, Synechococcus, picoeukaryotes, and heterotrophic bacteria) abundances during diatom bloom, the distribution of picoplankton in the Taiwan Bank, South China Sea was investigated using flow cytometry during a Thalassiosira diporocyclus bloom in March 2016. The results indicated an abrupt abundance decrease for Prochlorococcus, Synechococcus, and picoeukaryotes within the bloom area while the abundance of heterotrophic bacteria showed no significant difference between the bloom and non-bloom areas. We found two sub-groups of heterotrophic bacteria: high- and low-nucleic acid content (HNA and LNA) bacteria with HNA dominated in the bloom area whereas LNA dominated in the non-bloom area. Among the picoplankton components, HNA represented the highest (61.1%) carbon biomass in the bloom area while picoeukaryotes represented the highest (37.6%) in the non-bloom area. Our findings implied that heterotrophic bacteria, especially HNA, played an essential role during the diatom bloom. Copyright © 2017 Elsevier Ltd. All rights reserved.

Algal Blooms and Cyanotoxins in Jordan Lake, North Carolina

Directory of Open Access Journals (Sweden)

Daniel Wiltsie

2018-02-01

Full Text Available The eutrophication of waterways has led to a rise in cyanobacterial, harmful algal blooms (CyanoHABs worldwide. The deterioration of water quality due to excess algal biomass in lakes has been well documented (e.g., water clarity, hypoxic conditions, but health risks associated with cyanotoxins remain largely unexplored in the absence of toxin information. This study is the first to document the presence of dissolved microcystin, anatoxin-a, cylindrospermopsin, and β-N-methylamino-l-alanine in Jordan Lake, a major drinking water reservoir in North Carolina. Saxitoxin presence was not confirmed. Multiple toxins were detected at 86% of the tested sites and during 44% of the sampling events between 2014 and 2016. Although concentrations were low, continued exposure of organisms to multiple toxins raises some concerns. A combination of discrete sampling and in-situ tracking (Solid Phase Adsorption Toxin Tracking [SPATT] revealed that microcystin and anatoxin were the most pervasive year-round. Between 2011 and 2016, summer and fall blooms were dominated by the same cyanobacterial genera, all of which are suggested producers of single or multiple cyanotoxins. The study’s findings provide further evidence of the ubiquitous nature of cyanotoxins, and the challenges involved in linking CyanoHAB dynamics to specific environmental forcing factors are discussed.

Algal Blooms and Cyanotoxins in Jordan Lake, North Carolina.

Science.gov (United States)

Wiltsie, Daniel; Schnetzer, Astrid; Green, Jason; Vander Borgh, Mark; Fensin, Elizabeth

2018-02-24

The eutrophication of waterways has led to a rise in cyanobacterial, harmful algal blooms (CyanoHABs) worldwide. The deterioration of water quality due to excess algal biomass in lakes has been well documented (e.g., water clarity, hypoxic conditions), but health risks associated with cyanotoxins remain largely unexplored in the absence of toxin information. This study is the first to document the presence of dissolved microcystin, anatoxin-a, cylindrospermopsin, and β- N -methylamino-l-alanine in Jordan Lake, a major drinking water reservoir in North Carolina. Saxitoxin presence was not confirmed. Multiple toxins were detected at 86% of the tested sites and during 44% of the sampling events between 2014 and 2016. Although concentrations were low, continued exposure of organisms to multiple toxins raises some concerns. A combination of discrete sampling and in-situ tracking (Solid Phase Adsorption Toxin Tracking [SPATT]) revealed that microcystin and anatoxin were the most pervasive year-round. Between 2011 and 2016, summer and fall blooms were dominated by the same cyanobacterial genera, all of which are suggested producers of single or multiple cyanotoxins. The study's findings provide further evidence of the ubiquitous nature of cyanotoxins, and the challenges involved in linking CyanoHAB dynamics to specific environmental forcing factors are discussed.

Algal Blooms and Cyanotoxins in Jordan Lake, North Carolina

Science.gov (United States)

Wiltsie, Daniel; Schnetzer, Astrid; Green, Jason; Vander Borgh, Mark; Fensin, Elizabeth

2018-01-01

The eutrophication of waterways has led to a rise in cyanobacterial, harmful algal blooms (CyanoHABs) worldwide. The deterioration of water quality due to excess algal biomass in lakes has been well documented (e.g., water clarity, hypoxic conditions), but health risks associated with cyanotoxins remain largely unexplored in the absence of toxin information. This study is the first to document the presence of dissolved microcystin, anatoxin-a, cylindrospermopsin, and β-N-methylamino-l-alanine in Jordan Lake, a major drinking water reservoir in North Carolina. Saxitoxin presence was not confirmed. Multiple toxins were detected at 86% of the tested sites and during 44% of the sampling events between 2014 and 2016. Although concentrations were low, continued exposure of organisms to multiple toxins raises some concerns. A combination of discrete sampling and in-situ tracking (Solid Phase Adsorption Toxin Tracking [SPATT]) revealed that microcystin and anatoxin were the most pervasive year-round. Between 2011 and 2016, summer and fall blooms were dominated by the same cyanobacterial genera, all of which are suggested producers of single or multiple cyanotoxins. The study’s findings provide further evidence of the ubiquitous nature of cyanotoxins, and the challenges involved in linking CyanoHAB dynamics to specific environmental forcing factors are discussed. PMID:29495289

Impacts of algal blooms removal by chitosan-modified soils on zooplankton community in Taihu Lake,China

Institute of Scientific and Technical Information of China (English)

Jiajia Ni; Yuhe Yu; Weisong Feng; Qingyun Yan; Gang pan; Bo Yang; Xiang Zhang; Xuemei Li

2010-01-01

It is important to assess the effect on zooplankton when perform the environmental protection or restoration technology,especially removing algal blooms,because algae were the major primary producer in algal lakes.The influence on zooplankton community after half a year of algal blooms removed by chitosan-modified soils in Taihu Lake was assessed and the rationality of carrying out the process semiannually was evaluated in the present study.Morphological composition and genetic diversity of zooplankton community were investigated by microscope checkup and polymerase chain reaction-denatured gradient gel electrophoresis (PCR-DGGE).A total of 44 zooplankton taxa (23 protozoa,17 rotifers,3 copepoda and 1 cladocera) were detected by microscope checkup,and a total of 91 bands (28 bands amplified by primers F1427-GC and R1616,63 bands amplified by primers Fung-G-C and NS1) were detected by PCR-DGGE.The results of cluster analysis or detrended correspondence analysis indicated that there was no considerable difference in morphological composition of zooplankton and DGGE profiles between experimental and control sites,and DGGE profiles could represent the biologic diversity.The study showed that zooplankton community could recover original condition after half year of algal blooms removed by chitosan-modified soils and it was acceptable to apply this process semiannually.In addition,the results revealed that PCR-DGGE could be applied to investigate the impacts of the environmental protection or restoration engineering on zooplankton community diversity.

Process monitoring using optical ultrasonic wave detection

International Nuclear Information System (INIS)

Telschow, K.L.; Walter, J.B.; Garcia, G.V.; Kunerth, D.C.

1989-01-01

Optical ultrasonic wave detection techniques are being developed for process monitoring. An important limitation on optical techniques is that the material surface, in materials processing applications, is usually not a specular reflector and in many cases is totally diffusely reflecting. This severely degrades the light collected by the detection optics, greatly reducing the intensity and randomly scattering the phase of the reflected light. A confocal Fabry-Perot interferometer, which is sensitive to the Doppler frequency shift resulting from the surface motion and not to the phase of the collected light, is well suited to detecting ultrasonic waves in diffusely reflecting materials. This paper describes the application of this detector to the real-time monitoring of the sintering of ceramic materials. 8 refs., 5 figs

Satellite Evidence that E. huxleyi Phytoplankton Blooms Weaken Marine Carbon Sinks

Science.gov (United States)

Kondrik, D. V.; Pozdnyakov, D. V.; Johannessen, O. M.

2018-01-01

Phytoplankton blooms of the coccolithophore Emiliania huxleyi are known to produce CO2, causing less uptake of atmospheric CO2 by the ocean, but a global assessment of this phenomenon has so far not been quantified. Therefore, here we quantify the increase in CO2 partial pressure (ΔpCO2) at the ocean surface within E. huxleyi blooms for polar and subpolar seas using an 18 year ocean color time series (1998-2015). When normalized to pCO2 in the absence of bloom, the mean and maximum ΔpCO2 values within the bloom areas varied between 21.0%-43.3% and 31.6%-62.5%, respectively. These results might have appreciable implications for climatology, marine chemistry, and ecology.

New Coccolithophore Bloom in Bering Sea

Science.gov (United States)

2002-01-01

For the fourth year in a row it appears as if there is a bloom of coccolithophores-marine single-celled plants with calcite scales-in the Bering Sea off the coast of Alaska. Similar blooms were rare before 1997, but they have appeared every year since then. Scientists believe the coccolithophore blooms are the result of changing wind patterns in the region. Weaker than normal winds fail to mix the water of the Bering Sea, resulting in the growth of coccolithophores instead of other types of phytoplankton. Seabird populations have also been changing as a result of this climate change. The Sea-Viewing Wide Field-of-View Sensor (SeaWiFS), flying aboard the OrbView-2 satellite, saw the coccolith-brightened waters of the Bering Sea in 1997, 1998, and 1999. The waters have looked fairly bright again this winter and spring, as seen in this SeaWiFS image acquired April 29, 2000. But scientists are unsure whether this year's phenomenon is caused by living coccolithophorids, re-suspended coccoliths, or something else. Like all phytoplankton, coccolithophores contain chlorophyll and have the tendency to multiply rapidly near the surface. Yet, in large numbers, coccolithophores periodically shed their tiny scales, called 'coccoliths,' by the bucketful into the surrounding waters. The calcium-rich coccoliths turn the normally dark water a bright, milky aquamarine, making coccolithophore blooms easy to spot in satellite imagery. The edge of the whitish cloud in the water seen in this image is roughly 50 kilometers off the West Coast of Alaska. For more information see: SeaWiFS home page Changing Currents Color the Bering Sea a New Shade of Blue Image courtesy SeaWiFS project

Environmental dynamics of red Noctiluca scintillans bloom in tropical coastal waters.

Science.gov (United States)

Baliarsingh, S K; Lotliker, Aneesh A; Trainer, Vera L; Wells, Mark L; Parida, Chandanlal; Sahu, Biraja K; Srichandan, Suchismita; Sahoo, Subhashree; Sahu, K C; Kumar, T Sinivasa

2016-10-15

An intense bloom of red Noctiluca scintillans (NS) occurred off the Rushikulya estuarine region along the east coast of India, an important site for mass nesting events of the vulnerable Olive Ridley sea turtle. At its peak, densities of NS were 3.3×10(5) cells-l(-1), with low relative abundance of other phytoplankton. The peak bloom coincided with high abundance of gelatinous planktivores which may have facilitated bloom development by their grazing on other zooplankton, particularly copepods. Ammonium concentrations increased by approximately 4-fold in the later stages of bloom, coincident with stable NS abundance and chlorophyll concentrations in the nano- and microplankton. This increase likely was attributable to release of intracellular ammonium accumulated through NS grazing. Dissolved oxygen concentrations decreased in sub-surface waters to near hypoxia. Micro-phytoplankton increasingly dominated chlorophyll-a biomass as the bloom declined, with diminishing picoplankton abundance likely the result of high predation by the ciliate Mesodinium rubrum. Together, these data illustrate factors that can disrupt ecosystem balance in this critically important Indian coastal region. Copyright © 2016 Elsevier Ltd. All rights reserved.

Potential detection systems for monitoring UF6 releases

International Nuclear Information System (INIS)

Beck, D.E.; Bostick, W.D.; Armstrong, D.P.; McNeely, J.R.; Stockdale, J.A.D.

1994-09-01

In the near future, the Nuclear Regulatory Commission (NRC) will begin to regulate the gaseous diffusion plants. Them is a concern that the smoke detectors currently used for uranium hexafluoride (UF 6 ) release detection will not meet NRC safety system requirements such as high reliability and rapid response. The NRC's position is that licensees should utilize state-of-the-art equipment such as hydrogen fluoride (HF) detectors that would provide more dependable detection of a UF 6 release. A survey of the literature and current vendor information was undertaken to define the state-of-the-art and commercial availability of HF (or other appropriate) detection systems. For the purpose of this report, classification of the available HF detection systems is made on the basis of detection principle (e.g., calorimetric, electrochemical, separational, or optical). Emphasis is also placed on whether the device is primarily sensitive to response from a point source (e.g., outleakage in the immediate vicinity of a specific set of components), or whether the device is potentially applicable to remote sensing over a larger area. Traditional HF point source monitoring typically uses gas sampling tubes or coated paper tapes with color developing indicator, portable and small area HF monitors are often based upon electrochemical or extractive/separational systems; and remote sensing by optical systems holds promise for indoor and outdoor large area monitoring (including plant boundary/ambient air monitoring)

Analysis of Microcystins in Cyanobacterial Blooms from Freshwater Bodies in England

Directory of Open Access Journals (Sweden)

Andrew D. Turner

2018-01-01

Full Text Available Cyanobacterial blooms in freshwater bodies in England are currently monitored reactively, with samples containing more than 20,000 cells/mL of potentially toxin-producing species by light microscopy resulting in action by the water body owner. Whilst significantly reducing the risk of microcystin exposure, there is little data describing the levels of these toxins present in cyanobacterial blooms. This study focused on the quantitative LC-MS/MS analysis of microcystins in freshwater samples, collected across England during 2016 and found to contain potentially toxin-producing cyanobacteria. More than 50% of samples contained quantifiable concentrations of microcystins, with approximately 13% exceeding the WHO medium health threshold of 20 μg/L. Toxic samples were confirmed over a nine-month period, with a clear increase in toxins during late summer, but with no apparent geographical patterns. No statistical relationships were found between total toxin concentrations and environmental parameters. Complex toxin profiles were determined and profile clusters were unrelated to cyanobacterial species, although a dominance of MC-RR was determined in water samples from sites associated with lower rainfall. 100% of samples with toxins above the 20 μg/L limit contained cell densities above 20,000 cells/mL or cyanobacterial scum, showing the current regime is suitable for public health. Conversely, with only 18% of cell density threshold samples having total microcystins above 20 μg/L, there is the potential for reactive water closures to unnecessarily impact upon the socio-economics of the local population. In the future, routine analysis of bloom samples by LC-MS/MS would provide a beneficial confirmatory approach to the current microscopic assessment, aiding both public health and the needs of water users and industry.

Variation of particulate organic carbon and its relationship with bio-optical properties during a phytoplankton bloom in the Pearl River estuary

International Nuclear Information System (INIS)

Wang Guifen; Zhou Wen; Cao Wenxi; Yin Jianping; Yang Yuezhong; Sun Zhaohua; Zhang Yuanzhi; Zhao Jun

2011-01-01

Highlights: → A study about relationship between POC and optical properties during a phytoplankton bloom. → Empirical algorithms for retrieving POC concentration from optical data were developed. → Phytoplankton carbon and it's ratio to Chl-a are estimated and discussed. → Demonstrates that marine optical buoy can be a new platform for monitoring biogeochemical cycle. - Abstract: In this study, variations in the particulate organic carbon (POC) were monitored during a phytoplankton bloom event, and the corresponding changes in bio-optical properties were tracked at one station (114.29 o E, 22.06 o N) located in the Pearl River estuary. A greater than 10-fold increase in POC (112.29-1173.36 mg m -3 ) was observed during the bloom, with the chlorophyll a concentration (Chl-a) varying from 0.984 to 25.941 mg m -3 . A power law function is used to describe the relationship between POC and Chl-a, and the POC:Chl-a ratio tends to change inversely with Chl-a. Phytoplankton carbon concentration is indirectly estimated using the conceptual model proposed by , and this carbon is found to contribute 47.21% (±10.65%) to total POC. The estimated carbon-to-chlorophyll ratio of phytoplankton in diatom-dominated waters is found to be comparable with results reported in the literature. Empirical algorithms for determining the concentrations of Chl-a and POC were developed based on the relationships of these variables with the blue-to-green reflectance ratio. With these bio-optical models, the levels of particulate organic carbon and Chl-a could be predicted from the radiometric data measured by a marine optical buoy, which showed much more detailed information about the variability in biogeochemical parameters during this bloom event.

Fault Detection for Shipboard Monitoring and Decision Support Systems

DEFF Research Database (Denmark)

Lajic, Zoran; Nielsen, Ulrik Dam

2009-01-01

In this paper a basic idea of a fault-tolerant monitoring and decision support system will be explained. Fault detection is an important part of the fault-tolerant design for in-service monitoring and decision support systems for ships. In the paper, a virtual example of fault detection...... will be presented for a containership with a real decision support system onboard. All possible faults can be simulated and detected using residuals and the generalized likelihood ratio (GLR) algorithm....

The costs of respiratory illnesses arising from Florida gulf coast Karenia brevis blooms.

Science.gov (United States)

Hoagland, Porter; Jin, Di; Polansky, Lara Y; Kirkpatrick, Barbara; Kirkpatrick, Gary; Fleming, Lora E; Reich, Andrew; Watkins, Sharon M; Ullmann, Steven G; Backer, Lorraine C

2009-08-01

Algal blooms of Karenia brevis, a harmful marine algae, occur almost annually off the west coast of Florida. At high concentrations, K. brevis blooms can cause harm through the release of potent toxins, known as brevetoxins, to the atmosphere. Epidemiologic studies suggest that aerosolized brevetoxins are linked to respiratory illnesses in humans. We hypothesized a relationship between K. brevis blooms and respiratory illness visits to hospital emergency departments (EDs) while controlling for environmental factors, disease, and tourism. We sought to use this relationship to estimate the costs of illness associated with aerosolized brevetoxins. We developed a statistical exposure-response model to express hypotheses about the relationship between respiratory illnesses and bloom events. We estimated the model with data on ED visits, K. brevis cell densities, and measures of pollen, pollutants, respiratory disease, and intra-annual population changes. We found that lagged K. brevis cell counts, low air temperatures, influenza outbreaks, high pollen counts, and tourist visits helped explain the number of respiratory-specific ED diagnoses. The capitalized estimated marginal costs of illness for ED respiratory illnesses associated with K. brevis blooms in Sarasota County, Florida, alone ranged from $0.5 to $4 million, depending on bloom severity. Blooms of K. brevis lead to significant economic impacts. The costs of illness of ED visits are a conservative estimate of the total economic impacts. It will become increasingly necessary to understand the scale of the economic losses associated with K. brevis blooms to make rational choices about appropriate mitigation.

Macroalgal blooms favor heterotrophic diazotrophic bacteria in nitrogen-rich and phosphorus-limited coastal surface waters in the Yellow Sea

Science.gov (United States)

Zhang, Xiaoli; Song, Yanjing; Liu, Dongyan; Keesing, John K.; Gong, Jun

2015-09-01

Macroalgal blooms may lead to dramatic changes in physicochemical variables and biogeochemical cycling in affected waters. However, little is known about the effects of macroalgal blooms on marine bacteria, especially those functioning in nutrient cycles. We measured environmental factors and investigated bacterial diazotrophs in two niches, surface waters that were covered (CC) and non-covered (CF) with massive macroalgal canopies of Ulva prolifera, in the Yellow Sea in the summer of 2011 using real-time PCR and clone library analysis of nifH genes. We found that heterotrophic diazotrophs (Gammaproteobacteria) dominated the communities and were mostly represented by Vibrio-related phylotypes in both CC and CF. Desulfovibrio-related phylotypes were only detected in CC. There were significant differences in community composition in these two environments (p diazotrophic abundance and community composition and that vibrios and Desulfovibrio-related heterotrophic diazotrophs adapt well to the (N-rich but P-limited) environment during blooming. Potential ecological and microbiological mechanisms behind this scenario are discussed.

Remote Sensing Marine Ecology: Wind-driven algal blooms in the open oceans and their ecological impacts

Science.gov (United States)

Tang, DanLing

2016-07-01

Algal bloom not only can increase the primary production but also could result in negative ecological consequence, e.g., Harmful Algal Blooms (HABs). According to the classic theory for the formation of algal blooms "critical depth" and "eutrophication", oligotrophic sea area is usually difficult to form a large area of algal blooms, and actually the traditional observation is only sporadic capture to the existence of algal blooms. Taking full advantage of multiple data of satellite remote sensing, this study: 1), introduces "Wind-driven algal blooms in open oceans: observation and mechanisms" It explained except classic coastal Ekman transport, the wind through a variety of mechanisms affecting the formation of algal blooms. Proposed a conceptual model of "Strong wind -upwelling-nutrient-phytoplankton blooms" in Western South China Sea (SCS) to assess role of wind-induced advection transport in phytoplankton bloom formation. It illustrates the nutrient resources that support long-term offshore phytoplankton blooms in the western SCS; 2), Proposal of the theory that "typhoons cause vertical mixing, induce phytoplankton blooms", and quantify their important contribution to marine primary production; Proposal a new ecological index for typhoon. Proposed remote sensing inversion models. 3), Finding of the spatial and temporaldistributions pattern of harmful algal bloom (HAB)and species variations of HAB in the South Yellow Sea and East China Sea, and in the Pearl River estuary, and their oceanic dynamic mechanisms related with monsoon; The project developed new techniques and generated new knowledge, which significantly improved understanding of the formation mechanisms of algal blooms. 1), It proposed "wind-pump" mechanism integrates theoretical system combing "ocean dynamics, development of algal blooms, and impact on primary production", which will benefit fisheries management. 2), A new interdisciplinary subject "Remote Sensing Marine Ecology"(RSME) has been

Plant growth stage-specific injury and economic injury level for verde plant bug, Creontiades signatus (Hemiptera: Miridae), on cotton: effect of bloom period of infestation.

Science.gov (United States)

Brewer, Michael J; Anderson, Darwin J; Armstrong, J Scott

2013-10-01

Verde plant bugs, Creontiades signatus Distant (Hemiptera: Miridae), were released onto caged cotton, Cossypium hirsutum L., for a 1-wk period to characterize the effects of insect density and bloom period of infestation on cotton injury and yield in 2011 and 2012, Corpus Christi, TX. When plants were infested during early bloom (10-11 nodes above first white flower), a linear decline in fruit retention and boll load and a linear increase in boll injury were detected as verde plant bug infestation levels increased from an average of 0.5 to 4 bugs per plant. Lint and seed yield per plant showed a corresponding decline. Fruit retention, boll load, and yield were not affected on plants infested 1 wk later at peak bloom (8-9 nodes above first white flower), even though boll injury increased as infestation levels increased. Second-year testing verified boll injury but not yield loss, when infestations occurred at peak bloom. Incidence of cotton boll rot, known to be associated with verde plant bug feeding, was low to modest (verde plant bug were important contributors to yield decline, damage potential was greatest during the early bloom period of infestation, and a simple linear response best described the yield response-insect density relationship at early bloom. Confirmation that cotton after peak bloom was less prone to verde plant bug injury and an early bloom-specific economic injury level were key findings that can improve integrated pest management decision-making for dryland cotton, at least under low-rainfall growing conditions.

Siderophores: The special ingredient to cyanobacterial blooms

Science.gov (United States)

Du, Xue; Creed, Irena; Trick, Charles

2013-04-01

Freshwater lakes provide a number of significant ecological services including clean drinking water, habitat for aquatic biota, and economic benefits. The provision of these ecological services, as well as the health of these aquatic systems, is threatened by the excessive growth of algae, specifically, cyanobacteria. Historically, blooms have been linked to eutrophication but recent occurrences indicate that there are less dramatic changes that induce these blooms. Iron is an essential micronutrient required for specific essential metabolic pathways; however, the amount of biologically available iron in naturally occurring lake ranges from saturation to much lower than cell transport affinities. To assist in the modulation of iron availabilities, cyanobacteria in culture produce low molecular weight compounds that function in an iron binding and acquisition system; nevertheless, this has yet to be confirmed in naturally occurring lakes. This project explored the relationship of P, N and in particular, Fe, in the promotion of cyanobacteria harmful algal blooms in 30 natural freshwater lakes located in and around the Elk Island National Park, Alberta. It is hypothesized that cyanobacteria produce and utilize iron chelators called siderophores in low Fe and nitrogen (N) conditions, creating a competitive advantage over other algae in freshwater lakes. Lakes were selected to represent a range of iron availability to explore the nutrient composition of lakes that propagated cyanobacteria harmful algal blooms (cHABs) compared to lakes that did not. Lake water was analyzed for nutrients, microbial composition, siderophore concentration, and toxin concentration. Modifications were made to optimize the Czaky and Arnow tests for hydroxamate- and catecholate-type siderophores, respectively, for field conditions. Preliminary results indicate the presence of iron-binding ligands (0.11-2.34 mg/L) in freshwater lakes characterized by widely ranging Fe regimes (0.04-2.74 mg

Deep carbon export from a Southern Ocean iron-fertilized diatom bloom

Digital Repository Service at National Institute of Oceanography (India)

Smetacek, V.; Klaas, C.; Strass, V.H.; Assmy, P.; Montresor, M.; Cisewski, B.; Savoye, N.; Webb, A.; d’Ovidio, F.; Arrieta, J.M.; Bathmann, U.; Bellerby, R.; Berg, G.M.; Croot, P.; Gonzalez, S.; Henjes, J.; Herndl, G.J.; Hoffmann, L.J.; Leach, H.; Losch, M.; Mills, M.M.; Neill, C.; Peeken, I.; Rottgers, R.; Sachs, O.; Sauter, E.; Schmidt, M.M.; Schwarz, J.; Terbruggen, A.; Wolf-Gladrow, D.

Fertilization of the ocean by adding iron compounds has induced diatom-dominated phytoplankton blooms accompanied by considerable carbon dioxide drawdown in the ocean surface layer. However, because the fate of bloom biomass could not be adequately...

Evidence for a novel marine harmful algal bloom: cyanotoxin (microcystin transfer from land to sea otters.

Directory of Open Access Journals (Sweden)

Melissa A Miller

Full Text Available "Super-blooms" of cyanobacteria that produce potent and environmentally persistent biotoxins (microcystins are an emerging global health issue in freshwater habitats. Monitoring of the marine environment for secondary impacts has been minimal, although microcystin-contaminated freshwater is known to be entering marine ecosystems. Here we confirm deaths of marine mammals from microcystin intoxication and provide evidence implicating land-sea flow with trophic transfer through marine invertebrates as the most likely route of exposure. This hypothesis was evaluated through environmental detection of potential freshwater and marine microcystin sources, sea otter necropsy with biochemical analysis of tissues and evaluation of bioaccumulation of freshwater microcystins by marine invertebrates. Ocean discharge of freshwater microcystins was confirmed for three nutrient-impaired rivers flowing into the Monterey Bay National Marine Sanctuary, and microcystin concentrations up to 2,900 ppm (2.9 million ppb were detected in a freshwater lake and downstream tributaries to within 1 km of the ocean. Deaths of 21 southern sea otters, a federally listed threatened species, were linked to microcystin intoxication. Finally, farmed and free-living marine clams, mussels and oysters of species that are often consumed by sea otters and humans exhibited significant biomagnification (to 107 times ambient water levels and slow depuration of freshwater cyanotoxins, suggesting a potentially serious environmental and public health threat that extends from the lowest trophic levels of nutrient-impaired freshwater habitat to apex marine predators. Microcystin-poisoned sea otters were commonly recovered near river mouths and harbors and contaminated marine bivalves were implicated as the most likely source of this potent hepatotoxin for wild otters. This is the first report of deaths of marine mammals due to cyanotoxins and confirms the existence of a novel class of marine

Evidence for a novel marine harmful algal bloom: Cyanotoxin (Microcystin) transfer from land to sea otters

Science.gov (United States)

Miller, Melissa A.; Kudela, Raphael M.; Mekebri, Abdu; Crane, Dave; Oates, Stori C.; Tinker, M. Timothy; Staedler, Michelle; Miller, Woutrina A.; Toy-Choutka, Sharon; Dominik, Clare; Hardin, Dane; Langlois, Gregg; Murray, Michael; Ward, Kim; Jessup, David A.

2010-01-01

"Super-blooms" of cyanobacteria that produce potent and environmentally persistent biotoxins (microcystins) are an emerging global health issue in freshwater habitats. Monitoring of the marine environment for secondary impacts has been minimal, although microcystin-contaminated freshwater is known to be entering marine ecosystems. Here we confirm deaths of marine mammals from microcystin intoxication and provide evidence implicating land-sea flow with trophic transfer through marine invertebrates as the most likely route of exposure. This hypothesis was evaluated through environmental detection of potential freshwater and marine microcystin sources, sea otter necropsy with biochemical analysis of tissues and evaluation of bioaccumulation of freshwater microcystins by marine invertebrates. Ocean discharge of freshwater microcystins was confirmed for three nutrient-impaired rivers flowing into the Monterey Bay National Marine Sanctuary, and microcystin concentrations up to 2,900 ppm (2.9 million ppb) were detected in a freshwater lake and downstream tributaries to within 1 km of the ocean. Deaths of 21 southern sea otters, a federally listed threatened species, were linked to microcystin intoxication. Finally, farmed and free-living marine clams, mussels and oysters of species that are often consumed by sea otters and humans exhibited significant biomagnification (to 107 times ambient water levels) and slow depuration of freshwater cyanotoxins, suggesting a potentially serious environmental and public health threat that extends from the lowest trophic levels of nutrient-impaired freshwater habitat to apex marine predators. Microcystin-poisoned sea otters were commonly recovered near river mouths and harbors and contaminated marine bivalves were implicated as the most likely source of this potent hepatotoxin for wild otters. This is the first report of deaths of marine mammals due to cyanotoxins and confirms the existence of a novel class of marine "harmful algal

Triplexer Monitor Design for Failure Detection in FTTH System

Science.gov (United States)

Fu, Minglei; Le, Zichun; Hu, Jinhua; Fei, Xia

2012-09-01

Triplexer was one of the key components in FTTH systems, which employed an analog overlay channel for video broadcasting in addition to bidirectional digital transmission. To enhance the survivability of triplexer as well as the robustness of FTTH system, a multi-ports device named triplexer monitor was designed and realized, by which failures at triplexer ports can be detected and localized. Triplexer monitor was composed of integrated circuits and its four input ports were connected with the beam splitter whose power division ratio was 95∶5. By means of detecting the sampled optical signal from the beam splitters, triplexer monitor tracked the status of the four ports in triplexer (e.g. 1310 nm, 1490 nm, 1550 nm and com ports). In this paper, the operation scenario of the triplexer monitor with external optical devices was addressed. And the integrated circuit structure of the triplexer monitor was also given. Furthermore, a failure localization algorithm was proposed, which based on the state transition diagram. In order to measure the failure detection and localization time under the circumstance of different failed ports, an experimental test-bed was built. Experiment results showed that the detection time for the failure at 1310 nm port by the triplexer monitor was less than 8.20 ms. For the failure at 1490 nm or 1550 nm port it was less than 8.20 ms and for the failure at com port it was less than 7.20 ms.

Contributions of meteorology to the phenology of cyanobacterial blooms: implications for future climate change.

Science.gov (United States)

Zhang, Min; Duan, Hongtao; Shi, Xiaoli; Yu, Yang; Kong, Fanxiang

2012-02-01

Cyanobacterial blooms are often a result of eutrophication. Recently, however, their expansion has also been found to be associated with changes in climate. To elucidate the effects of climatic variables on the expansion of cyanobacterial blooms in Taihu, China, we analyzed the relationships between climatic variables and bloom events which were retrieved by satellite images. We then assessed the contribution of each climate variable to the phenology of blooms using multiple regression models. Our study demonstrates that retrieving ecological information from satellite images is meritorious for large-scale and long-term ecological research in freshwater ecosystems. Our results show that the phenological changes of blooms at an inter-annual scale are strongly linked to climate in Taihu during the past 23 yr. Cyanobacterial blooms occur earlier and last longer with the increase of temperature, sunshine hours, and global radiation and the decrease of wind speed. Furthermore, the duration increases when the daily averages of maximum, mean, and minimum temperature each exceed 20.3 °C, 16.7 °C, and 13.7 °C, respectively. Among these factors, sunshine hours and wind speed are the primary contributors to the onset of the blooms, explaining 84.6% of their variability over the past 23 yr. These factors are also good predictors of the variability in the duration of annual blooms and determined 58.9% of the variability in this parameter. Our results indicate that when nutrients are in sufficiently high quantities to sustain the formation of cyanobacterial blooms, climatic variables become crucial in predicting cyanobacterial bloom events. Climate changes should be considered when we evaluate how much the amount of nutrients should be reduced in Taihu for lake management. Copyright © 2011 Elsevier Ltd. All rights reserved.

Climate Adaptation and Harmful Algal Blooms

Science.gov (United States)

EPA supports local, state and tribal efforts to maintain water quality. A key element of its efforts is to reduce excess nutrient pollution and the resulting adverse impacts, including harmful algal blooms.

Phytoplankton dynamics in contrasting early stage North Atlantic spring blooms: composition, succession, and potential drivers

DEFF Research Database (Denmark)

Daniels, C.J.; Poulton, A. J.; Esposito, M.

2015-01-01

The spring bloom is a key annual event in the phenology of pelagic ecosystems, making a major contribution to the oceanic biological carbon pump through the production and export of organic carbon. However, there is little consensus as to the main drivers of spring bloom formation, exacerbated......) of the 2012 North Atlantic spring bloom. The plankton composition and characteristics of the initial stages of the bloom were markedly different between the two basins. The Iceland Basin (ICB) appeared well mixed to > 400 m, yet surface chlorophyll a (0.27–2.2 mg m–3) and primary production (0.06–0.66 mmol C...... suggest micro-zooplankton grazing, potentially coupled with the lack of a seed population of bloom forming diatoms, was restricting diatom growth in the NWB, and that large diatoms may be absent in NWB spring blooms. Despite both phytoplankton communities being in the early stages of bloom formation...

Unpacking the Revised Bloom's Taxonomy: Developing Case-Based Learning Activities

Science.gov (United States)

Nkhoma, Mathews Zanda; Lam, Tri Khai; Sriratanaviriyakul, Narumon; Richardson, Joan; Kam, Booi; Lau, Kwok Hung

2017-01-01

Purpose: The purpose of this paper is to propose the use of case studies in teaching an undergraduate course of Internet for Business in class, based on the revised Bloom's taxonomy. The study provides the empirical evidence about the effect of case-based teaching method integrated the revised Bloom's taxonomy on students' incremental learning,…

Development of the composition of chocolate mass that resistant to bloom

Directory of Open Access Journals (Sweden)

M. E. Tkeshelashvili

2017-01-01

Full Text Available Chocolate or used as a coating on the surface of the sweets chocolate mass when exposed to a temperature drop and/or a drop in the humidity of the environment, change color, lose gloss and acquire an unwanted grayish-white surface. The loss of the appearance of chocolate – the effect of bloom is the reason for the return of products from the trading network causing highly tangible the economic damage to the producers. In this connection, experimental researches devoted to the problem of preventing bloom and developing consist of chocolate masses preclusion to bloom appear to be an urgent task. The purpose of the research is develop consist of chocolate and covering chocolate resistant to bloom. The work is performed at the Scientific research institute of «Applied research of innovative technologies and food quality» of Plekhanov Russian University of Economics. For an investigation, samples of chocolate and covering chocolate based on cocoa butter were made in the formulation of which an additive including milk fat/isomalt/polydextrose. The control samples were dark chocolate and covering chocolate prepared according to a unified formula. For the formation of blooming, the samples were exposed to temperature fluctuations and relative humidity. The measurement of the color of chocolate is implementation by an instrumental method based on the analysis of the optical characteristics of the product. The coefficients of reflection spectra of samples of chocolate were converted into color coordinates of space CIEL ? a ? b* 1976. The emergence of a bloom of chocolate by changing the parameter lightness L ? (CIEL ? a ? b* was diagnosed. The effect of introducing an additive, including milk fat/isomalt/polydextrose on fat and sugar bloom, was determined in the formulation of chocolate masses. Based on research the consist of the chocolate mass has been developed which practically does not change the taste of the finished chocolate products

Service discovery using Bloom filters

NARCIS (Netherlands)

Goering, P.T.H.; Heijenk, Geert; Lelieveldt, B.P.F.; Haverkort, Boudewijn R.H.M.; de Laat, C.T.A.M.; Heijnsdijk, J.W.J.

A protocol to perform service discovery in adhoc networks is introduced in this paper. Attenuated Bloom filters are used to distribute services to nodes in the neighborhood and thus enable local service discovery. The protocol has been implemented in a discrete event simulator to investigate the

Privacy-Preserving Electrocardiogram Monitoring for Intelligent Arrhythmia Detection †

Science.gov (United States)

Son, Junggab; Park, Juyoung; Oh, Heekuck; Bhuiyan, Md Zakirul Alam; Hur, Junbeom; Kang, Kyungtae

2017-01-01

Long-term electrocardiogram (ECG) monitoring, as a representative application of cyber-physical systems, facilitates the early detection of arrhythmia. A considerable number of previous studies has explored monitoring techniques and the automated analysis of sensing data. However, ensuring patient privacy or confidentiality has not been a primary concern in ECG monitoring. First, we propose an intelligent heart monitoring system, which involves a patient-worn ECG sensor (e.g., a smartphone) and a remote monitoring station, as well as a decision support server that interconnects these components. The decision support server analyzes the heart activity, using the Pan–Tompkins algorithm to detect heartbeats and a decision tree to classify them. Our system protects sensing data and user privacy, which is an essential attribute of dependability, by adopting signal scrambling and anonymous identity schemes. We also employ a public key cryptosystem to enable secure communication between the entities. Simulations using data from the MIT-BIH arrhythmia database demonstrate that our system achieves a 95.74% success rate in heartbeat detection and almost a 96.63% accuracy in heartbeat classification, while successfully preserving privacy and securing communications among the involved entities. PMID:28604628

Determination and occurrence of retinoids in a eutrophic lake (Taihu Lake, China): cyanobacteria blooms produce teratogenic retinal.

Science.gov (United States)

Wu, Xiaoqin; Jiang, Jieqiong; Hu, Jianying

2013-01-15

Besides retinoic acids (RAs), some retinoids such as retinal (RAL) and retinol (ROH), which are considered as RA precursors in vertebrates, are also reported to be teratogenic agents. In this study we investigated four RA precursors including RAL, ROH, retinyl palmitate, and β-carotene in the eutrophic Taihu Lake, China, by developing a sensitive analytical method. RAL and β-carotene were widely detected in natural cyanobacteria blooms and lake water. Intracellular concentrations of RAL and β-carotene in blooms were 9.4 to 6.9 × 10(3) and 3.4 to 1.8 × 10(5) ng L(-1), respectively, and their concentrations in lake water were up to 1.4 × 10 ng L(-1) (RAL) and 9.8 × 10(2) ng L(-1) (β-carotene). The good correlation between intracellular concentrations of RAL and RAs implied that RAL was involved in the production of RAs by cyanobacteria blooms. Further examination of 39 cyanobacteria and algae species revealed that most species could produce RAL and β-carotene. The greatest amount of RAL was found in Chlamydomonas sp. (FACHB-715; 1.9 × 10(3) ng g(-1) dry weight). As the main cyanobacteria in Taihu Lake, many Microcystis species could produce high amounts of RAL and were thought to greatly contribute to the production of RAL measured in the blooms. Productions of RAL and β-carotene by cyanobacteria were associated with species, origin location, and growth stage. The results in this study present the existence of a potential risk to aquatic animals living in a eutrophic environment from a high concentration of RAL in cyanobacteria blooms and also provide a clue for further investigating the mechanism underlying the biosynthetic pathway of RAs in cyanobacteria and algae.

Hydrodynamic control of microphytoplankton bloom in a coastal sea

Science.gov (United States)

Murty, K. Narasimha; Sarma, Nittala S.; Pandi, Sudarsana Rao; Chiranjeevulu, Gundala; Kiran, Rayaprolu; Muralikrishna, R.

2017-08-01

The influence of hydrodynamics on phytoplankton bloom occurrence/formation has not been adequately reported. Here, we document diurnal observations in the tropical Bay of Bengal's mid-western shelf region which reveal microphytoplankton cell density maxima in association with neap tide many times more than what could be accounted for by solar insolation and nutrient levels. When in summer, phytoplankton cells were abundant and the cell density of Guinardia delicatula reached critical value by tide caused zonation, aggregation happened to an intense bloom. Mucilaginous exudates from the alga due to heat and silicate stress likely promoted and stable water column and weak winds left undisturbed, the transient bloom. The phytoplankton aggregates have implication as food resource in the benthic region implying higher fishery potential, in carbon dioxide sequestration (carbon burial) and in efforts towards improving remote sensing algorithms for chlorophyll in the coastal region.

Climbing Bloom's taxonomy pyramid: Lessons from a graduate histology course.

Science.gov (United States)

Zaidi, Nikki B; Hwang, Charles; Scott, Sara; Stallard, Stefanie; Purkiss, Joel; Hortsch, Michael

2017-09-01

Bloom's taxonomy was adopted to create a subject-specific scoring tool for histology multiple-choice questions (MCQs). This Bloom's Taxonomy Histology Tool (BTHT) was used to analyze teacher- and student-generated quiz and examination questions from a graduate level histology course. Multiple-choice questions using histological images were generally assigned a higher BTHT level than simple text questions. The type of microscopy technique (light or electron microscopy) used for these image-based questions did not result in any significant differences in their Bloom's taxonomy scores. The BTHT levels for teacher-generated MCQs correlated positively with higher discrimination indices and inversely with the percent of students answering these questions correctly (difficulty index), suggesting that higher-level Bloom's taxonomy questions differentiate well between higher- and lower-performing students. When examining BTHT scores for MCQs that were written by students in a Multiple-Choice Item Development Assignment (MCIDA) there was no significant correlation between these scores and the students' ability to answer teacher-generated MCQs. This suggests that the ability to answer histology MCQs relies on a different skill set than the aptitude to construct higher-level Bloom's taxonomy questions. However, students significantly improved their average BTHT scores from the midterm to the final MCIDA task, which indicates that practice, experience and feedback increased their MCQ writing proficiency. Anat Sci Educ 10: 456-464. © 2017 American Association of Anatomists. © 2017 American Association of Anatomists.

Rising CO2 levels will intensify phytoplankton blooms in eutrophic and hypertrophic lakes.

Directory of Open Access Journals (Sweden)

Jolanda M H Verspagen

Full Text Available Harmful algal blooms threaten the water quality of many eutrophic and hypertrophic lakes and cause severe ecological and economic damage worldwide. Dense blooms often deplete the dissolved CO2 concentration and raise pH. Yet, quantitative prediction of the feedbacks between phytoplankton growth, CO2 drawdown and the inorganic carbon chemistry of aquatic ecosystems has received surprisingly little attention. Here, we develop a mathematical model to predict dynamic changes in dissolved inorganic carbon (DIC, pH and alkalinity during phytoplankton bloom development. We tested the model in chemostat experiments with the freshwater cyanobacterium Microcystis aeruginosa at different CO2 levels. The experiments showed that dense blooms sequestered large amounts of atmospheric CO2, not only by their own biomass production but also by inducing a high pH and alkalinity that enhanced the capacity for DIC storage in the system. We used the model to explore how phytoplankton blooms of eutrophic waters will respond to rising CO2 levels. The model predicts that (1 dense phytoplankton blooms in low- and moderately alkaline waters can deplete the dissolved CO2 concentration to limiting levels and raise the pH over a relatively wide range of atmospheric CO2 conditions, (2 rising atmospheric CO2 levels will enhance phytoplankton blooms in low- and moderately alkaline waters with high nutrient loads, and (3 above some threshold, rising atmospheric CO2 will alleviate phytoplankton blooms from carbon limitation, resulting in less intense CO2 depletion and a lesser increase in pH. Sensitivity analysis indicated that the model predictions were qualitatively robust. Quantitatively, the predictions were sensitive to variation in lake depth, DIC input and CO2 gas transfer across the air-water interface, but relatively robust to variation in the carbon uptake mechanisms of phytoplankton. In total, these findings warn that rising CO2 levels may result in a marked

Chaos Theory and James Joyce's "ulysses": Leopold Bloom as a Human COMPLEX@SYSTEM^

Science.gov (United States)

Mackey, Peter Francis

1995-01-01

These four ideas apply as much to our lives as to the life of Leopold Bloom: (1) A trivial decision can wholly change a life. (2) A chance encounter can dramatically alter life's course. (3) A contingent nexus exists between consciousness and environment. (4) A structure of meaning helps us interpret life's chaos. These ideas also relate to a contemporary science called by some "chaos theory." The connection between Ulysses and chaos theory enhances our understanding of Bloom's day; it also suggests that this novel may be about the real process of life itself. The first chapter explains how Joyce's own essays and comments to friends compel attention to the links between Ulysses and chaos theory. His scientific contemporaries anticipated chaos theory, and their ideas seem to have rubbed off on him. We see this in his sense of trivial things and chance, his modernistic organizational impulses, and the contingent nature of Bloom's experience. The second chapter studies what chaos theory and Joyce's ideas tell us about "Ithaca," the episode which particularly implicates our processes of interpreting this text as well as life itself as we face their chaos. The third chapter examines Bloom's close feel for the aboriginal world, a contingency that clarifies his vulnerability to trivial changes. The fourth chapter studies how Bloom's stream of consciousness unfolds--from his chance encounters with trivial things. Beneath this stream's seeming chaos, Bloom's distinct personality endures, similar to how Joyce's schemas give Ulysses an imbedded, underlying order. The fifth chapter examines how trivial perturbations, such as Lyons' misunderstanding about "Throwaway," produce small crises for Bloom, exacerbating his seeming impotence before his lonely "fate.". The final chapter analyzes Bloom's views that fate and chance dictate his life. His views provide an opportunity to explore the implications chaos theory has for our understanding of free will and determinism. Ultimately

Rising CO2 Levels Will Intensify Phytoplankton Blooms in Eutrophic and Hypertrophic Lakes

Science.gov (United States)

Verspagen, Jolanda M. H.; Van de Waal, Dedmer B.; Finke, Jan F.; Visser, Petra M.; Van Donk, Ellen; Huisman, Jef

2014-01-01

Harmful algal blooms threaten the water quality of many eutrophic and hypertrophic lakes and cause severe ecological and economic damage worldwide. Dense blooms often deplete the dissolved CO2 concentration and raise pH. Yet, quantitative prediction of the feedbacks between phytoplankton growth, CO2 drawdown and the inorganic carbon chemistry of aquatic ecosystems has received surprisingly little attention. Here, we develop a mathematical model to predict dynamic changes in dissolved inorganic carbon (DIC), pH and alkalinity during phytoplankton bloom development. We tested the model in chemostat experiments with the freshwater cyanobacterium Microcystis aeruginosa at different CO2 levels. The experiments showed that dense blooms sequestered large amounts of atmospheric CO2, not only by their own biomass production but also by inducing a high pH and alkalinity that enhanced the capacity for DIC storage in the system. We used the model to explore how phytoplankton blooms of eutrophic waters will respond to rising CO2 levels. The model predicts that (1) dense phytoplankton blooms in low- and moderately alkaline waters can deplete the dissolved CO2 concentration to limiting levels and raise the pH over a relatively wide range of atmospheric CO2 conditions, (2) rising atmospheric CO2 levels will enhance phytoplankton blooms in low- and moderately alkaline waters with high nutrient loads, and (3) above some threshold, rising atmospheric CO2 will alleviate phytoplankton blooms from carbon limitation, resulting in less intense CO2 depletion and a lesser increase in pH. Sensitivity analysis indicated that the model predictions were qualitatively robust. Quantitatively, the predictions were sensitive to variation in lake depth, DIC input and CO2 gas transfer across the air-water interface, but relatively robust to variation in the carbon uptake mechanisms of phytoplankton. In total, these findings warn that rising CO2 levels may result in a marked intensification of

Change-Point Detection Method for Clinical Decision Support System Rule Monitoring.

Science.gov (United States)

Liu, Siqi; Wright, Adam; Hauskrecht, Milos

2017-06-01

A clinical decision support system (CDSS) and its components can malfunction due to various reasons. Monitoring the system and detecting its malfunctions can help one to avoid any potential mistakes and associated costs. In this paper, we investigate the problem of detecting changes in the CDSS operation, in particular its monitoring and alerting subsystem, by monitoring its rule firing counts. The detection should be performed online, that is whenever a new datum arrives, we want to have a score indicating how likely there is a change in the system. We develop a new method based on Seasonal-Trend decomposition and likelihood ratio statistics to detect the changes. Experiments on real and simulated data show that our method has a lower delay in detection compared with existing change-point detection methods.

Trophic linkage of a temperate intertidal macrobenthic food web under opportunistic macroalgal blooms: A stable isotope approach

International Nuclear Information System (INIS)

Park, Hyun Je; Han, Eunah; Lee, Young-Jae; Kang, Chang-Keun

2016-01-01

The effects of blooms of opportunistic green macroalgae, Ulva prolifera, on the trophic structure of the macrobenthic food web in a temperate intertidal zone on the western coast of Korea were evaluated using carbon and nitrogen stable isotopes. Biomasses of Ulva and microphytobenthos (MPB) increased significantly at the macroalgae-bloom and the non-bloom sites, respectively, from March to September 2011. The δ 13 C values of most the consumers were arrayed between those of MPB and Ulva at both sites, and differed according to feeding strategies at the macroalgae-bloom site. Seasonally increasing magnitudes in δ 13 C and δ 15 N values of consumers were much steeper at the macroalgae-bloom site than at the non-bloom site. Our findings provide evidence that blooming green macroalgae play a significant role as a basal resource supporting the intertidal macrobenthic food web and their significance varies with feeding strategies of consumers as well as the resource availability. - Highlights: • Trophic effects of Ulva blooms on intertidal macrobenthic food web were evaluated. • Biomasses of Ulva increased at the macroalgae-bloom from March to September. • δ 13 C and δ 15 N values of consumers differed with feeding strategy and season. • Trophic significance of blooming macroalgae varies with feeding strategies of consumers. • Ulva blooms play a significant role as a basal resource supporting the intertidal food web.

Effects of fertilizers used in agricultural fields on algal blooms

DEFF Research Database (Denmark)

Chakraborty, Subhendu; Tiwari, P. K.; Sasmal, S. K.

2017-01-01

of factors and from observation it is difficult to identify the most important one. In the present paper, using a mathematical model we compare the effects of three human induced factors (fertilizer input in agricultural field, eutrophication due to other sources than fertilizers, and overfishing......) on the bloom dynamics and DO level. By applying a sophisticated sensitivity analysis technique, we found that the increasing use of fertilizers in agricultural field causes more rapid algal growth and decreases DO level much faster than eutrophication from other sources and overfishing. We also look...... at the mechanisms how fertilizer input rate affects the algal bloom dynamics and DO level. The model can be helpful for the policy makers in determining the influential factors responsible for the bloom formation....

Evaluation of fatty acids as biomarkers for a natural plankton community. A field study of a spring bloom and a post-bloom period off West Greenland

DEFF Research Database (Denmark)

Reuss, N.; Poulsen, Louise K.

2002-01-01

community were taken at the depth of fluorescence maximum. High biomass and diatom dominance during the spring bloom and low biomass and flagellate dominance in the post-bloom period were reflected by the fatty acid profiles. The total amount of fatty acid ranged from 55 to 132 mug 1(-1) during the spring...

Petal Thicknesses and Shape Transformations in Blooming Lilies

Energy Technology Data Exchange (ETDEWEB)

Portet, Thomas; Holmes, Peter N.; Bowden, Mark E.; Stephens, Sean A.; Varga, Tamas; Keller, Sarah L.

2013-01-29

During blooming, flower petals undergo significant shape changes. For lilies, various different mechanisms responsible for the change have been suggested [1,2]. One is that cell growth along the edge of a petal, or, more generally, a tepal, drives a transition from a cup shape (within a bud) to a saddle shape (within a bloom). This mechanism has been previously considered for tepals modeled as shallow elliptical shells whose thickness from the center, t, falls off at least as fast as t = t0 (1 - x2/a2 - y2/b2 ) [1]. Here t0 is the maximum thickness of the shell, a and b are the semimajor and semiminoraxes, x and y are the coordinates along the longitudinal and lateral axes. By measuring tepal thicknesses from images collected by x-ray tomography of intact buds and by photography of microtomed buds, we find that this condition is indeed met for both Lilium casablanca and Lilium lancifolium. [1] Liang and Mahadevan. Growth, geometry, and mechanics of a blooming lily.

Importance of deep mixing for initiating the North Atlantic spring bloom

DEFF Research Database (Denmark)

Riisgaard, Karen; Paulsen, Maria Lund; Thingstad, T. Frede

The phytoplankton spring bloom is one of the most important recurrent events in the sup-polar part of the Atlantic Ocean. The classical idea is that the bloom is controlled by nutrients and light, but recent observations challenge this hypothesis. During repeated visits to stations in the deep...

Field and laboratory guide to freshwater cyanobacteria harmful algal blooms for Native American and Alaska Native communities

Science.gov (United States)

Rosen, Barry H.; St. Amand, Ann

2015-09-14

Cyanobacteria can produce toxins and form harmful algal blooms. The Native American and Alaska Native communities that are dependent on subsistence fishing have an increased risk of exposure to these cyanotoxins. It is important to recognize the presence of an algal bloom in a waterbody and to distinguish a potentially toxic harmful algal bloom from a non-toxic bloom. This guide provides field images that show cyanobacteria blooms, some of which can be toxin producers, as well as other non-toxic algae blooms and floating plants that might be confused with algae. After recognition of a potential toxin-producing cyanobacterial bloom in the field, the type(s) of cyanobacteria present needs to be identified. Species identification, which requires microscopic examination, may help distinguish a toxin-producer from a non-toxin producer. This guide also provides microscopic images of the common cyanobacteria that are known to produce toxins, as well as images of algae that form blooms but do not produce toxins.

An integrated method for removal of harmful cyanobacterial blooms in eutrophic lakes

International Nuclear Information System (INIS)

Wang Zhicong; Li Dunhai; Qin Hongjie; Li Yinxia

2012-01-01

As the eutrophication of lakes becomes an increasingly widespread phenomenon, cyanobacterial blooms are occurring in many countries. Although some research has been reported, there is currently no good method for bloom removal. We propose here a new two-step integrated approach to resolve this problem. The first step is the inactivation of the cyanobacteria via the addition of H 2 O 2 . We found 60 mg/L was the lowest effective dose for a cyanobacterial concentration corresponding to 100 μg/L chlorophyll-a. The second step is the flocculation and sedimentation of the inactivated cyanobacteria. We found the addition of lake sediment clay (2 g/L) plus polymeric ferric sulfate (20 mg/L) effectively deposited them on the lake bottom. Since algaecides and flocculants had been used separately in previous reports, we innovatively combined these two types of reagents to remove blooms from the lake surface and to improve the dissolved oxygen content of lake sediments. - Graphical abstract: The mechanism for the removal of cyanobacterial blooms by using H 2 O 2 , polymeric ferric sulfate (PFS) and lake sediment clay. Display Omitted Highlights: ► We combined algaecide and flocculants together to control cyanobacterial blooms. ► H 2 O 2 was used to irreversibly inactivate the photosynthesis of cyanobacteria. ► Lake sediment clay and polymeric ferric sulfate were used to deposit cyanobacteria. ► Removal rate was very high and re-suspension rate was very low under disturbance. ► The inactivated cyanobacteria could not serve as a seed source for the next bloom. - Inactivation by H 2 O 2 and sedimentation using polymeric ferric sulfate and sediment clay demonstrated high integrated efficiency in removal of cyanobacterial blooms.

A Preliminary Bloom's Taxonomy Assessment of End-of-Chapter Problems in Business School Textbooks

Science.gov (United States)

Marshall, Jennings B.; Carson, Charles M.

2008-01-01

This article examines textbook problems used in a sampling of some of the most common core courses found in schools of business to ascertain what level of learning, as defined by Bloom's Taxonomy, is required to provide a correct answer. A set of working definitions based on Bloom's Taxonomy (Bloom & Krathwohl, 1956) was developed for the six…

Factors affecting outbreaks of Cochlodinium polykrikoides blooms in coastal areas of Korea

International Nuclear Information System (INIS)

Lee, Young Sik . E-mail leeyodk@hanmail.net; Lee, Sang Yong

2006-01-01

We evaluated the causes of the first outbreak of Cochlodinium polykrikoides blooms in Narodo and the Southern coast of Namhaedo on the South Sea, as well as the outbreak of C. polykrikoides blooms in the East Sea and around Wando. From the results of AGP tests using diverse seawater types, we identified seawaters in which C. polykrikoides grow well and those in which they do not, depending on the sampling time and location. The reason for C. polykrikoides blooms initially occurring in Narodo, Namhaedo, and Gujaedo seems to be because the seawater that promotes the growth of C. polykrikoides is transported to the areas of primary generation, such as these three areas, by the influence of the Tsushima Warm Current. The reason that C. polykrikoides blooms occur in the coastal area of Wando and the East Sea is because after the seawater promoting the growth of C. polykrikoides is transported to these areas, the amount of sun radiation increases, and abundant nutrients flow in from heavy rains, resulting in mass propagation of C. polykrikoides. The origin of the seawater that promotes the growth of C. polykrikoides is assumed to be the southern section of the southern coastal area of Narodo, Namhaedo, and Gujaedo, in which C. polykrikoides blooms were initially discovered. The components of the f/2 medium (N, P, Fe, Mn, Co, Cu, Zn, Mo, B12, biotin, thiamine) do not seem to trigger the occurrence of C. polykrikoides blooms

Aldehyde suppression of copepod recruitment in blooms of a ubiquitous planktonic diatom

Science.gov (United States)

Ianora, Adrianna; Miralto, Antonio; Poulet, Serge A.; Carotenuto, Ylenia; Buttino, Isabella; Romano, Giovanna; Casotti, Raffaella; Pohnert, Georg; Wichard, Thomas; Colucci-D'Amato, Luca; Terrazzano, Giuseppe; Smetacek, Victor

2004-05-01

The growth cycle in nutrient-rich, aquatic environments starts with a diatom bloom that ends in mass sinking of ungrazed cells and phytodetritus. The low grazing pressure on these blooms has been attributed to the inability of overwintering copepod populations to track them temporally. We tested an alternative explanation: that dominant diatom species impair the reproductive success of their grazers. We compared larval development of a common overwintering copepod fed on a ubiquitous, early-blooming diatom species with its development when fed on a typical post-bloom dinoflagellate. Development was arrested in all larvae in which both mothers and their larvae were fed the diatom diet. Mortality remained high even if larvae were switched to the dinoflagellate diet. Aldehydes, cleaved from a fatty acid precursor by enzymes activated within seconds after crushing of the cell, elicit the teratogenic effect. This insidious mechanism, which does not deter the herbivore from feeding but impairs its recruitment, will restrain the cohort size of the next generation of early-rising overwinterers. Such a transgenerational plant-herbivore interaction could explain the recurringly inefficient use of a predictable, potentially valuable food resource-the spring diatom bloom-by marine zooplankton.

Retrieved bacteria from Noctiluca miliaris (green) bloom of the northeastern Arabian Sea

Digital Repository Service at National Institute of Oceanography (India)

Basu, S.; Matondkar, S.G.P.; Furtado, I.

In recent years, seasonal blooms of the dinoflagellate Noctiluca miliaris have appeared in the open-waters of the northern Arabian Sea (NAS). This study provides the first characterization of bacteria from a seasonal bloom of green Noctiluca of NAS...

Experimental estimation of snare detectability for robust threat monitoring.

Science.gov (United States)

O'Kelly, Hannah J; Rowcliffe, J Marcus; Durant, Sarah; Milner-Gulland, E J

2018-02-01

Hunting with wire snares is rife within many tropical forest systems, and constitutes one of the severest threats to a wide range of vertebrate taxa. As for all threats, reliable monitoring of snaring levels is critical for assessing the relative effectiveness of management interventions. However, snares pose a particular challenge in terms of tracking spatial or temporal trends in their prevalence because they are extremely difficult to detect, and are typically spread across large, inaccessible areas. As with cryptic animal targets, any approach used to monitor snaring levels must address the issue of imperfect detection, but no standard method exists to do so. We carried out a field experiment in Keo Seima Wildlife Reserve in eastern Cambodia with the following objectives: (1) To estimate the detection probably of wire snares within a tropical forest context, and to investigate how detectability might be affected by habitat type, snare type, or observer. (2) To trial two sets of sampling protocols feasible to implement in a range of challenging field conditions. (3) To conduct a preliminary assessment of two potential analytical approaches to dealing with the resulting snare encounter data. We found that although different observers had no discernible effect on detection probability, detectability did vary between habitat type and snare type. We contend that simple repeated counts carried out at multiple sites and analyzed using binomial mixture models could represent a practical yet robust solution to the problem of monitoring snaring levels both inside and outside of protected areas. This experiment represents an important first step in developing improved methods of threat monitoring, and such methods are greatly needed in southeast Asia, as well as in as many other regions.

Whole body personnel monitoring via ionization detection

International Nuclear Information System (INIS)

Koster, J.E.; Bounds, K.A.; Kerr, P.L.; Steadman, P.A.; Whitley, C.R.

1998-02-01

A project between Fernald EMP and LANL is to field a monitor for the detection of alpha-emitting contamination on a human body. Traditional personnel monitoring for alpha emitters involves either frisking with a probe or pressing against large detectors in order to overcome the short range of alpha particles. These methods have a low alpha collection efficiency, and can miss contamination on less accessible surfaces. The authors have investigated the sensitivity and practicality of measuring the entire subject simultaneously using the technique of ionization monitoring. The goal is to create a booth that personnel step into quickly during egress from radiological facilities. The detection technique relies on a breeze of air passing over the subject. Alpha emission produces copious ions in the ambient air which are transported by the air current to an ion collector, resulting in a small electrical current proportional to the amount of contamination. Results indicate a conservative sensitivity of 3,000 disintegrations per minute localized to one of five areas of the body in a measurement lasting less than 2 minutes

Cyanobacterial blooms in lake Atitlan, Guatemala

Czech Academy of Sciences Publication Activity Database

Rejmánková, E.; Komárek, Jiří; Dix, M.; Komárková, Jaroslava; Girón, N.

2011-01-01

Roč. 41, č. 4 (2011), s. 296-302 ISSN 0075-9511 Institutional research plan: CEZ:AV0Z60050516; CEZ:AV0Z60170517 Keywords : water blooms * plancton * Guatemala Subject RIV: EH - Ecology, Behaviour Impact factor: 1.527, year: 2011

Wide-area monitoring to detect undeclared nuclear facilities

International Nuclear Information System (INIS)

Wogman, N.

1994-09-01

The International Atomic Energy Agency (IAEA) is committed to strengthening and streamlining the overall effectiveness of the IAEA safeguards system. The IAEA is investigating the use of environmental monitoring techniques to strengthen its capability to detect undeclared nuclear activities. The IAEA's Program 93+2 Initiative has been established to develop, test, and assess strengthening techniques and measures. Some of the techniques have been validated and are being implemented during routine safeguards inspections. The effectiveness of other techniques is being studied as a part of extensive field trials conducted at nuclear facilities of various Member States during 1993 and 1994. Proposals based on the results of these investigations and recommendations for new safeguards activities are expected to be presented to the March 1995 Board of Governors Meeting. The techniques in use or under study during IAEA field trials address various types of environmental monitoring applications as outlined under Program 93+2's Task 3, Environmental Monitoring Techniques for Safeguards Applications, namely, the use of short-range monitoring during inspections and visits to investigate sites of possible undeclared activities. With the exception of wide-area water sampling in Iraq, the use of long-range monitoring, in the absence of any indication of undeclared nuclear activities, remains largely unexamined by the IAEA. The efficacy of long-range monitoring depends on the availability of mobile signature isotopes or compounds and on the ability to distinguish the nuclear signatures from background signals and attributing them to a source. The scope of this paper is to provide technical information to the International Atomic Energy Agency (IAEA) on possible wide-area survey techniques for the detection of undeclared nuclear activities. The primary focus is the detection of effluents from reprocessing activities

Effects of ocean acidification on marine dissolved organic matter are not detectable over the succession of phytoplankton blooms.

Science.gov (United States)

Zark, Maren; Riebesell, Ulf; Dittmar, Thorsten

2015-10-01

Marine dissolved organic matter (DOM) is one of the largest active organic carbon reservoirs on Earth, and changes in its pool size or composition could have a major impact on the global carbon cycle. Ocean acidification is a potential driver for these changes because it influences marine primary production and heterotrophic respiration. We simulated ocean acidification as expected for a "business-as-usual" emission scenario in the year 2100 in an unprecedented long-term mesocosm study. The large-scale experiments (50 m(3) each) covered a full seasonal cycle of marine production in a Swedish Fjord. Five mesocosms were artificially enriched in CO2 to the partial pressure expected in the year 2100 (900 μatm), and five more served as controls (400 μatm). We applied ultrahigh-resolution mass spectrometry to monitor the succession of 7360 distinct DOM formulae over the course of the experiment. Plankton blooms had a clear effect on DOM concentration and molecular composition. This succession was reproducible across all 10 mesocosms, independent of CO2 treatment. In contrast to the temporal trend, there were no significant differences in DOM concentration and composition between present-day and year 2100 CO2 levels at any time point of the experiment. On the basis of our results, ocean acidification alone is unlikely to affect the seasonal accumulation of DOM in productive coastal environments.

After effects of a dinoflagellate bloom on the hard bottom community in Kalpakkam coastal waters

International Nuclear Information System (INIS)

Sasikumar, N.; Azariah, J.; Venugopalan, V.P.; Nair, K.V.K.

1989-01-01

A bloom of the dinoflagellate, Noctiluca scintillans (Macartney) was observed in Kalpakkam coastal waters during the second and third week of October, 1988. Associated with the incidence of the bloom, signficant variations in the distribution of intertidal hard bottom communities were observed. Considerable difference in the dissolved oxygen content was also recorded during the bloom period. A sudden disapperance of grazers like limpets was observed after the onset of the bloom. Subsequent to this, there was a recolonization process, which showed a regular succession. Following limpet disappearance there was a rapid 'greening' of the surface by Enteromorpha Later, Dictyota dichotoma excluded Enteromorpha. Experimental teak wood panels also showed a decline in cy prid settlement during the bloom. (author). 3 tabs., 19 refs

Occurrence of toxin-producing cyanobacteria blooms in a Brazilian semiarid reservoir

Directory of Open Access Journals (Sweden)

I. A. S. Costa

Full Text Available We report the occurrence of cyanobacterial blooms and the presence of cyanotoxins in water samples from the Armando Ribeiro Gonçalves reservoir (06° 08’ S and 37° 07’ W, located in the state of Rio Grande do Norte, in the semiarid region of northeastern Brazil. The cyanobacterial species were identified and quantified during the rainy and dry seasons in the year 2000. Cyanotoxins such as microcystins, saxitoxins and cylindrospermopsins were analyzed and quantified using HPLC and ELISA methods. The mixed toxic blooms of Cylindrospermopsis raciborskii, Microcystis spp (M. panniformis, M. protocystis, M. novacekii and Aphanizomenon spp (Aphanizomenon gracile, A. cf. manguinii, A. cf. issastschenkoi were persistent and represented 90-100% of the total phytoplankton species. Toxic cyanobacterial blooms from the Armando Ribeiro Gonçalves reservoir were analyzed and found to have three phases in relation to the annual cycle. During the rainy season, an intense toxic bloom of Cylindrospermopsis raciborskii was recorded along with saxitoxins (3.14 µg.L-1. During the transition period, between the rainy and dry seasons, different species of Microscytis occurred and microcystin as high as 8.8 µg.L-1 was recorded. In the dry season, co-dominance of Cylindrospermopsis raciborskii, Microcystis spp and Aphanizomenon spp occurred and the concentrations of saxitoxin remained very low. Our results indicate the presence of microcystins (8.8 µg.L-1 and saxitoxins (3.14 µg.L-1 into the crude water, with increasing concentrations from the second fortnight of April to late May 2000. The occurrence of toxic blooms in this reservoir points to a permanent risk of cyanotoxins in supply waters, indicating the need for the implementation of bloom control measures to improve the water quality. Exposure of the local population to cyanotoxins through their potential accumulation in fish muscle must also be considered.

FFTF fuel failure detection and characterization by cover gas monitoring. Final report

International Nuclear Information System (INIS)

Miller, W.C.; Holt, F.E.

1977-01-01

The Fast Flux Test Facility (FFTF) will include a Fuel Failure Monitoring (FFM) System designed to detect, characterize, and locate fuel and absorber pin failures (i.e., cladding breaches) using a combination of delayed neutron detection, cover gas radioisotope monitoring, and gas tagging. During the past several years the Hanford Engineering Development Laboratory has been involved in the development, design, procurement, and installation of this integrated system. The paper describes one portion of the FFM System, the Cover Gas Monitoring System (CGMS), which has the primary function of fuel failure detection and characterization in the FFTF. By monitoring the various radioisotopes in the cover gas, the CGMS will both detect fuel and absorber pin failures and characterize those failures as to magnitude and severity

State of knowledge and concerns on cyanobacterial blooms and cyanotoxins.

OpenAIRE

Merel , Sylvain; Walker , David; Chicana , Ruth; Snyder , Shane; Baurès , Estelle; Thomas , Olivier

2013-01-01

International audience; Cyanobacteria are ubiquitous microorganisms considered as important contributors to the formation of Earth's atmosphere and nitrogen fixation. However, they are also frequently associated with toxic blooms. Indeed, the wide range of hepatotoxins, neurotoxins and dermatotoxins synthesized by these bacteria is a growing environmental and public health concern. This paper provides a state of the art on the occurrence and management of harmful cyanobacterial blooms in surf...

Detecting System of Nested Hardware Virtual Machine Monitor

Directory of Open Access Journals (Sweden)

Artem Vladimirovich Iuzbashev

2015-03-01

Full Text Available Method of nested hardware virtual machine monitor detection was proposed in this work. The method is based on HVM timing attack. In case of HVM presence in system, the number of different instruction sequences execution time values will increase. We used this property as indicator in our detection.

[Application of lysosomal detection in marine pollution monitoring: research progress].

Science.gov (United States)

Weng, You-Zhu; Fang, Yong-Qiang; Zhang, Yu-Sheng

2013-11-01

Lysosome is an important organelle existing in eukaryotic cells. With the development of the study on the structure and function of lysosome in recent years, lysosome is considered as a target of toxic substances on subcellular level, and has been widely applied abroad in marine pollution monitoring. This paper summarized the biological characteristics of lysosomal marker enzyme, lysosome-autophagy system, and lysosomal membrane, and introduced the principles and methods of applying lysosomal detection in marine pollution monitoring. Bivalve shellfish digestive gland and fish liver are the most sensitive organs for lysosomal detection. By adopting the lysosomal detection techniques such as lysosomal membrane stability (LMS) test, neutral red retention time (NRRT) assay, morphological measurement (MM) of lysosome, immunohistochemical (Ih) assay of lysosomal marker enzyme, and electron microscopy (EM), the status of marine pollution can be evaluated. It was suggested that the lysosome could be used as a biomarker for monitoring marine environmental pollution. The advantages and disadvantages of lysosomal detection and some problems worthy of attention were analyzed, and the application prospects of lysosomal detection were discussed.

Allan Bloom, America, and Education.

Science.gov (United States)

West, Thomas

2000-01-01

Refutes the claims of Allan Bloom that the source of the problem with today's universities is modern philosophy, that the writings and ideas of Hobbes and Locke planted the seeds of relativism in American culture, and that the cure is Great Books education. Suggests instead that America's founding principles are the only solution to the failure of…

Multilevel Bloom Filters for P2P Flows Identification Based on Cluster Analysis in Wireless Mesh Network

Directory of Open Access Journals (Sweden)

Xia-an Bi

2015-01-01

Full Text Available With the development of wireless mesh networks and distributed computing, lots of new P2P services have been deployed and enrich the Internet contents and applications. The rapid growth of P2P flows brings great pressure to the regular network operation. So the effective flow identification and management of P2P applications become increasingly urgent. In this paper, we build a multilevel bloom filters data structure to identify the P2P flows through researches on the locality characteristics of P2P flows. Different level structure stores different numbers of P2P flow rules. According to the characteristics values of the P2P flows, we adjust the parameters of the data structure of bloom filters. The searching steps of the scheme traverse from the first level to the last level. Compared with the traditional algorithms, our method solves the drawbacks of previous schemes. The simulation results demonstrate that our algorithm effectively enhances the performance of P2P flows identification. Then we deploy our flow identification algorithm in the traffic monitoring sensors which belong to the network traffic monitoring system at the export link in the campus network. In the real environment, the experiment results demonstrate that our algorithm has a fast speed and high accuracy to identify the P2P flows; therefore, it is suitable for actual deployment.

Dynamic Changes in Bacterial Population and Corresponding Exoenzyme Activity in Response to a Tropical Phytoplankton Bloom Chattonella marina

Directory of Open Access Journals (Sweden)

Anit M. Thomas

2014-01-01

Full Text Available The raphidophyte Chattonella marina (Subrahmanyan Hara & Chihara bloom which causes lethal effects on marine ecosystem has been reported intermittently from Indian waters. In the present study, periodic samplings were made in a Chattonella marina bloom area, off Mahe, on 27 and 29 October and 1 November 2011 (in different phases of the bloom to assess the associated bacterial population and their exoenzyme activity. Microbial community composition of Chattonella marina bloom revealed a twentyfold increase in bacterial load over the nonbloom area. The bacterial genera, Micrococcus, Flavobacterium, Vibrio, and Pseudomonas, increased significantly during the declining phase of the bloom. An assessment of the extracellular enzyme production also showed a marked increase in percentage of bacterial strains, potent in protease production, suggesting the possible role of proteolytic bacteria in bloom crash. This study reveals the bacterial community succession during the bloom and indicates that bacteria play an important role in bloom regulation.

A Hybrid Change Detection Approach for Damage Detection and Recovery Monitoring

Science.gov (United States)

de Alwis Pitts, Dilkushi; Wieland, Marc; Wang, Shifeng; So, Emily; Pittore, Massimiliano

2014-05-01

Following a disaster, change detection via pre- and post-event very high resolution remote sensing images is an essential technique for damage assessment and recovery monitoring over large areas in complex urban environments. Most assessments to date focus on detection, destruction and recovery of man-made objects that facilitate shelter and accessibility, such as buildings, roads, bridges, etc., as indicators for assessment and better decision making. Moreover, many current change-detection mechanisms do not use all the data and knowledge which are often available for the pre-disaster state. Recognizing the continuous rather than dichotomous character of the data-rich/data-poor distinction permits the incorporation of ancillary data and existing knowledge into the processing flow. Such incorporation could improve the reliability of the results and thereby enhance the usability of robust methods for disaster management. This study proposes an application-specific and robust change detection method from multi-temporal very high resolution multi-spectral satellite images. This hybrid indicator-specific method uses readily available pre-disaster GIS data and integrates existing knowledge into the processing flow to optimize the change detection while offering the possibility to target specific types of changes to man-made objects. The indicator-specific information of the GIS objects is used as a series of masks to treat the GIS objects with similar characteristics similarly for better accuracy. The proposed approach is based on a fusion of a multi-index change detection method based on gradient, texture and edge similarity filters. The change detection index is flexible for disaster cases in which the pre-disaster and post-disaster images are not of the same resolution. The proposed automated method is evaluated with QuickBird and Ikonos datasets for abrupt changes soon after disaster. The method could also be extended in a semi-automated way for monitoring

Challenges in modeling spatiotemporally varying phytoplankton blooms in the Northwestern Arabian Sea and Gulf of Oman

Science.gov (United States)

Sedigh Marvasti, S.; Gnanadesikan, A.; Bidokhti, A. A.; Dunne, J. P.; Ghader, S.

2016-02-01

Recent years have shown an increase in harmful algal blooms in the Northwest Arabian Sea and Gulf of Oman, raising the question of whether climate change will accelerate this trend. This has led us to examine whether the Earth System Models used to simulate phytoplankton productivity accurately capture bloom dynamics in this region - both in terms of the annual cycle and interannual variability. Satellite data (SeaWIFS ocean color) show two climatological blooms in this region, a wintertime bloom peaking in February and a summertime bloom peaking in September. On a regional scale, interannual variability of the wintertime bloom is dominated by cyclonic eddies which vary in location from one year to another. Two coarse (1°) models with the relatively complex biogeochemistry (TOPAZ) capture the annual cycle but neither eddies nor the interannual variability. An eddy-resolving model (GFDL CM2.6) with a simpler biogeochemistry (miniBLING) displays larger interannual variability, but overestimates the wintertime bloom and captures eddy-bloom coupling in the south but not in the north. The models fail to capture both the magnitude of the wintertime bloom and its modulation by eddies in part because of their failure to capture the observed sharp thermocline and/or nutricline in this region. When CM2.6 is able to capture such features in the Southern part of the basin, eddies modulate diffusive nutrient supply to the surface (a mechanism not previously emphasized in the literature). For the model to simulate the observed wintertime blooms within cyclones, it will be necessary to represent this relatively unusual nutrient structure as well as the cyclonic eddies. This is a challenge in the Northern Arabian Sea as it requires capturing the details of the outflow from the Persian Gulf - something that is poorly done in global models.

Algal toxins and reverse osmosis desalination operations: Laboratory bench testing and field monitoring of domoic acid, saxitoxin, brevetoxin and okadaic acid

KAUST Repository

Seubert, Erica L.

2012-12-01

The occurrence and intensity of harmful algal blooms (HABs) have been increasing globally during the past few decades. The impact of these events on seawater desalination facilities has become an important topic in recent years due to enhanced societal interest and reliance on this technology for augmenting world water supplies. A variety of harmful bloom-forming species of microalgae occur in southern California, as well as many other locations throughout the world, and several of these species are known to produce potent neurotoxins. These algal toxins can cause a myriad of human health issues, including death, when ingested via contaminated seafood. This study was designed to investigate the impact that algal toxin presence may have on both the intake and reverse osmosis (RO) desalination process; most importantly, whether or not the naturally occurring algal toxins can pass through the RO membrane and into the desalination product. Bench-scale RO experiments were conducted to explore the potential of extracellular algal toxins contaminating the RO product. Concentrations exceeding maximal values previously reported during natural blooms were used in the laboratory experiments, with treatments comprised of 50 μg/L of domoic acid (DA), 2 μg/L of saxitoxin (STX) and 20 μg/L of brevetoxin (PbTx). None of the algal toxins used in the bench-scale experiments were detectable in the desalinated product water. Monitoring for intracellular and extracellular concentrations of DA, STX, PbTx and okadaic acid (OA) within the intake and desalinated water from a pilot RO desalination plant in El Segundo, CA, was conducted from 2005 to 2009. During the five-year monitoring period, DA and STX were detected sporadically in the intake waters but never in the desalinated water. PbTx and OA were not detected in either the intake or desalinated water. The results of this study demonstrate the potential for HAB toxins to be inducted into coastal RO intake facilities, and the

Algal toxins and reverse osmosis desalination operations: Laboratory bench testing and field monitoring of domoic acid, saxitoxin, brevetoxin and okadaic acid

KAUST Repository

Seubert, Erica L.; Trussell, Shane; Eagleton, John; Schnetzer, Astrid; Cetinić, Ivona; Lauri, Phil; Jones, Burton; Caron, David A.

2012-01-01

The occurrence and intensity of harmful algal blooms (HABs) have been increasing globally during the past few decades. The impact of these events on seawater desalination facilities has become an important topic in recent years due to enhanced societal interest and reliance on this technology for augmenting world water supplies. A variety of harmful bloom-forming species of microalgae occur in southern California, as well as many other locations throughout the world, and several of these species are known to produce potent neurotoxins. These algal toxins can cause a myriad of human health issues, including death, when ingested via contaminated seafood. This study was designed to investigate the impact that algal toxin presence may have on both the intake and reverse osmosis (RO) desalination process; most importantly, whether or not the naturally occurring algal toxins can pass through the RO membrane and into the desalination product. Bench-scale RO experiments were conducted to explore the potential of extracellular algal toxins contaminating the RO product. Concentrations exceeding maximal values previously reported during natural blooms were used in the laboratory experiments, with treatments comprised of 50 μg/L of domoic acid (DA), 2 μg/L of saxitoxin (STX) and 20 μg/L of brevetoxin (PbTx). None of the algal toxins used in the bench-scale experiments were detectable in the desalinated product water. Monitoring for intracellular and extracellular concentrations of DA, STX, PbTx and okadaic acid (OA) within the intake and desalinated water from a pilot RO desalination plant in El Segundo, CA, was conducted from 2005 to 2009. During the five-year monitoring period, DA and STX were detected sporadically in the intake waters but never in the desalinated water. PbTx and OA were not detected in either the intake or desalinated water. The results of this study demonstrate the potential for HAB toxins to be inducted into coastal RO intake facilities, and the

Challenges in modelling spatiotemporally varying phytoplankton blooms in the Northwestern Arabian Sea and Gulf of Oman

Science.gov (United States)

Sedigh Marvasti, S.; Gnanadesikan, A.; Bidokhti, A. A.; Dunne, J. P.; Ghader, S.

2015-07-01

We examine interannual variability of phytoplankton blooms in northwestern Arabian Sea and Gulf of Oman. Satellite data (SeaWIFS ocean color) shows two climatological blooms in this region, a wintertime bloom peaking in February and a summertime bloom peaking in September. A pronounced anti-correlation between the AVISO sea surface height anomaly (SSHA) and chlorophyll is found during the wintertime bloom. On a regional scale, interannual variability of the wintertime bloom is thus dominated by cyclonic eddies which vary in location from one year to another. These results were compared against the outputs from three different 3-D Earth System models. We show that two coarse (1°) models with the relatively complex biogeochemistry (TOPAZ) capture the annual cycle but neither eddies nor the interannual variability. An eddy-resolving model (GFDL CM2.6) with a simpler biogeochemistry (miniBLING) displays larger interannual variability, but overestimates the wintertime bloom and captures eddy-bloom coupling in the south but not in the north. The southern part of the domain is a region with a much sharper thermocline and nutricline relatively close to the surface, in which eddies modulate diffusive nutrient supply to the surface (a mechanism not previously emphasized in the literature). We suggest that for the model to simulate the observed wintertime blooms within cyclones, it will be necessary to represent this relatively unusual nutrient structure as well as the cyclonic eddies. This is a challenge in the Northern Arabian Sea as it requires capturing the details of the outflow from the Persian Gulf.

Climbing Bloom's Taxonomy Pyramid: Lessons from a Graduate Histology Course

Science.gov (United States)

Zaidi, Nikki B.; Hwang, Charles; Scott, Sara; Stallard, Stefanie; Purkiss, Joel; Hortsch, Michael

2017-01-01

Bloom's taxonomy was adopted to create a subject-specific scoring tool for histology multiple-choice questions (MCQs). This Bloom's Taxonomy Histology Tool (BTHT) was used to analyze teacher- and student-generated quiz and examination questions from a graduate level histology course. Multiple-choice questions using histological images were…

Harmful Algal Blooms in the Mississippi Sound and Mobile Bay: Using MODIS Aqua and In Situ Data for HABs in the Northern Gulf of Mexico

National Research Council Canada - National Science Library

Holiday, Dan; Carter, Gregory; Gould, Richard W; MacIntyre, Hugh

2007-01-01

This study investigates the use of satellite remote sensing to detect blooms and predict environmental conditions leading to the formation of HAVs in the turbid coastal waters along the Mississippi and Alabama shores...

Amalgamation of Anomaly-Detection Indices for Enhanced Process Monitoring

KAUST Repository

Harrou, Fouzi

2016-01-29

Accurate and effective anomaly detection and diagnosis of modern industrial systems are crucial for ensuring reliability and safety and for maintaining desired product quality. Anomaly detection based on principal component analysis (PCA) has been studied intensively and largely applied to multivariate processes with highly cross-correlated process variables; howver conventional PCA-based methods often fail to detect small or moderate anomalies. In this paper, the proposed approach integrates two popular process-monitoring detection tools, the conventional PCA-based monitoring indices Hotelling’s T2 and Q and the exponentially weighted moving average (EWMA). We develop two EWMA tools based on the Q and T2 statistics, T2-EWMA and Q-EWMA, to detect anomalies in the process mean. The performances of the proposed methods were compared with that of conventional PCA-based anomaly-detection methods by applying each method to two examples: a synthetic data set and experimental data collected from a flow heating system. The results clearly show the benefits and effectiveness of the proposed methods over conventional PCA-based methods.

Site fidelity by bees drives pollination facilitation in sequentially blooming plant species.

Science.gov (United States)

Ogilvie, Jane E; Thomson, James D

2016-06-01

Plant species can influence the pollination and reproductive success of coflowering neighbors that share pollinators. Because some individual pollinators habitually forage in particular areas, it is also possible that plant species could influence the pollination of neighbors that bloom later. When flowers of a preferred forage plant decline in an area, site-fidelity may cause individual flower feeders to stay in an area and switch plant species rather than search for preferred plants in a new location. A newly blooming plant species may quickly inherit a set of visitors from a prior plant species, and therefore experience higher pollination success than it would in an area where the first species never bloomed. To test this, we manipulated the placement and timing of two plant species, Delphinium barbeyi and later-blooming Gentiana parryi. We recorded the responses of individually marked bumble bee pollinators. About 63% of marked individuals returned repeatedly to the same areas to forage on Delphinium. When Delphinium was experimentally taken out of bloom, most of those site-faithful individuals (78%) stayed and switched to Gentiana. Consequently, Gentiana flowers received more visits in areas where Delphinium had previously flowered, compared to areas where Delphinium was still flowering or never occurred. Gentiana stigmas received more pollen in areas where Delphinium disappeared than where it never bloomed, indicating that Delphinium increases the pollination of Gentiana when they are separated in time. Overall, we show that individual bumble bees are often site-faithful, causing one plant species to increase the pollination of another even when separated in time, which is a novel mechanism of pollination facilitation.

Acoustic system for pipe rupture monitoring and leak detection

International Nuclear Information System (INIS)

Herzog, W.; Jonas, H.

1982-06-01

As a safety aspect pipe rupture and leakage effects are of particular interest in nuclear power plants where severe consequences for the reactor may result. Counter measures against postulated pipe breaks and leakages in nuclear power plants are necessary whenever the main safety goals: safe shut-down, safe afterheat removal and retention of radioactivity, are endangered. The requirements to be met by a leak detection system depend on the time available for counter actions. If this time is short so that automatic actions are necessary the German safety criteria for nuclear power plants (Criterion 6.1) require two physically diverse signals to be monitored. One fairly obvious possibility of leak detection is to monitor process parameters (pressure, flow). As a diverse signal physical parameters outside the process may be employed: pressure transients temperature, humidity are principally suitable. In practical application, however, it is difficult to predict these parameters by way of calculation in order to establish the required set-point of the monitoring system. Experimental determination is possible only in special cases. A study of several ways of diverse leak detection methods leads to the very promising acoustic method. We investigated experimentally the feasibility of monitoring the sound created by a leakage. Air borne sound as well as body borne sound was analyzed

Diversity and dynamics of a widespread bloom of the toxic dinoflagellate Alexandrium fundyense.

Directory of Open Access Journals (Sweden)

Deana L Erdner

Full Text Available Historically, cosmopolitan phytoplankton species were presumed to represent largely unstructured populations. However, the recent development of molecular tools to examine genetic diversity have revealed differences in phytoplankton taxa across geographic scales and provided insight into the physiology and ecology of blooms. Here we describe the genetic analysis of an extensive bloom of the toxic dinoflagellate Alexandrium fundyense that occurred in the Gulf of Maine in 2005. This bloom was notable for its intensity and duration, covering hundreds of kilometers and persisting for almost two months. Genotypic analyses based on microsatellite marker data indicate that the open waters of the northeastern U.S. harbor a single regional population of A. fundyense comprising two genetically distinct sub-populations. These subpopulations were characteristic of early- and late-bloom samples and were derived from the northern and southern areas of the bloom, respectively. The temporal changes observed during this study provide clear evidence of succession during a continuous bloom and show that selection can act on the timescale of weeks to significantly alter the representation of genotypes within a population. The effects of selection on population composition and turnover would be magnified if sexual reproduction were likewise influenced by environmental conditions. We hypothesize that the combined effects of differential growth and reproduction rates serves to reduce gene flow between the sub-populations, reinforcing population structure while maintaining the diversity of the overall regional population.

Study on loss detection algorithms using tank-monitoring data

International Nuclear Information System (INIS)

Suzuki, Mitsutoshi; Hori, Masato; Nagaoka, Shinichi; Kimura, Takashi

2009-01-01

An application of solution monitoring to material balance evaluation has been investigated with actual data from the Solution Monitoring Management System (SMMS) in the Tokai Reprocessing Plant (TRP). Loss detection capabilities of the proposed multivariate statistical methods are examined numerically for a simulated loss corresponding to parameters of a significant quantity in the wait mode. Multiscale statistical analysis as well as multivariate cumulative sum analysis are successfully used to demonstrate the protracted-loss detection. Because the actual tank data is composed of records in both the wait and transfer modes, the tank-to-tank transferring data is extracted from the sequence of monitoring data, and the error model effectiveness is evaluated in comparison with calculations. Although the data taken from the SMMS does not describe the entire solution process, an extended application of solution monitoring to the nuclear material accounting is advanced using the plant data, and future research subjects are described. (author)

Design and application of a surface vessel for autonomous inland water monitoring

OpenAIRE

Hitz Gregory; Pomerleau Francois; Garneau Marie-Eve; Pradalier Cedric; Posch Thomas; Pernthaler Jakob; Siegwart Roland

2012-01-01

This article presents a novel autonomous surface vessel (ASV) that was designed and manufactured specifically for the monitoring of water resources resources that are not only constantly drained but also face the growing threat of mass proliferation (bloom) of noxious cyanobacteria. On one hand the distribution of these blooms in a given water body requires a surveillance of biological data at high spatial resolution on both vertical and horizontal axes whereas on the other hand the understan...

Detection and monitoring of early caries lesions

DEFF Research Database (Denmark)

Pretty, I A; Ekstrand, K R

2016-01-01

and co-workers from 2013 and this still represents the current state of the science in relation to caries detection and monitoring. The review described among others, visible detection systems, image-based detection systems and point-measurement approaches. RESULTS: The current evidence base suggests...... that while there are numerous devices or technology-enabled detection systems, the use of a careful, methodical visual inspection of clean, dry teeth, supplemented where indicated by radiographic views, remains the standard of care in caries detection and diagnostics. Further, it is possible by means...... to the clinician and the patient for whom it may be a useful educational and motivational tool. CONCLUSIONS: Recommendations are presented that can be adopted and adapted to local circumstances and that are both substantiated by evidence and promote a clear, simple and consistent approach to caries detection...

Physical control of interannual variations of the winter chlorophyll bloom in the northern Arabian Sea

Directory of Open Access Journals (Sweden)

M. G. Keerthi

2017-08-01

Full Text Available The northern Arabian Sea hosts a winter chlorophyll bloom, triggered by convective overturning in response to cold and dry northeasterly monsoon winds. Previous studies of interannual variations of this bloom only relied on a couple of years of data and reached no consensus on the associated processes. The current study aims at identifying these processes using both  ∼  10 years of observations (including remotely sensed chlorophyll data and physical parameters derived from Argo data and a 20-year-long coupled biophysical ocean model simulation. Despite discrepancies in the estimated bloom amplitude, the six different remotely sensed chlorophyll products analysed in this study display a good phase agreement at seasonal and interannual timescales. The model and observations both indicate that the interannual winter bloom fluctuations are strongly tied to interannual mixed layer depth anomalies ( ∼  0.6 to 0.7 correlation, which are themselves controlled by the net heat flux at the air–sea interface. Our modelling results suggest that the mixed layer depth control of the bloom amplitude ensues from the modulation of nutrient entrainment into the euphotic layer. In contrast, the model and observations both display insignificant correlations between the bloom amplitude and thermocline depth, which precludes a control of the bloom amplitude by daily dilution down to the thermocline depth, as suggested in a previous study.

Seasonal and annual dynamics of harmful algae and algal toxins revealed through weekly monitoring at two coastal ocean sites off southern California, USA

KAUST Repository

Seubert, Erica L.

2013-01-04

Reports of toxic harmful algal blooms (HABs) attributed to the diatom Pseudo-nitzschia spp. have been increasing in California during the last several decades. Whether this increase can be attributed to enhanced awareness and monitoring or to a dramatic upswing in the development of HAB events remains unresolved. Given these uncertainties, the ability to accurately and rapidly identify an emerging HAB event is of high importance. Monitoring of HAB species and other pertinent chemical/physical parameters at two piers in southern California, Newport and Redondo Beach, was used to investigate the development of a site-specific bloom definition for identifying emerging domoic acid (DA) events. Emphasis was given to abundances of the Pseudo-nitzschia seriata size category of Pseudo-nitzschia due to the prevalence of this size class in the region. P. seriata bloom thresholds were established for each location based on deviations from their respective long-term mean abundances, allowing the identification of major and minor blooms. Sixty-five percent of blooms identified at Newport Beach coincided with measurable DA concentrations, while 36 % of blooms at Redondo Beach coincided with measurable DA. Bloom definitions allowed for increased specificity in multiple regression analysis of environmental forcing factors significant to the presence of DA and P. seriata. The strongest relationship identified was between P. seriata abundances 2 weeks following upwelling events at Newport Beach. © 2012 Springer-Verlag Berlin Heidelberg.

Seasonal and annual dynamics of harmful algae and algal toxins revealed through weekly monitoring at two coastal ocean sites off southern California, USA

KAUST Repository

Seubert, Erica L.; Gellene, Alyssa G.; Howard, Meredith D Armstrong; Connell, Paige; Ragan, Matthew; Jones, Burton; Runyan, Jennifer; Caron, David A.

2013-01-01

Reports of toxic harmful algal blooms (HABs) attributed to the diatom Pseudo-nitzschia spp. have been increasing in California during the last several decades. Whether this increase can be attributed to enhanced awareness and monitoring or to a dramatic upswing in the development of HAB events remains unresolved. Given these uncertainties, the ability to accurately and rapidly identify an emerging HAB event is of high importance. Monitoring of HAB species and other pertinent chemical/physical parameters at two piers in southern California, Newport and Redondo Beach, was used to investigate the development of a site-specific bloom definition for identifying emerging domoic acid (DA) events. Emphasis was given to abundances of the Pseudo-nitzschia seriata size category of Pseudo-nitzschia due to the prevalence of this size class in the region. P. seriata bloom thresholds were established for each location based on deviations from their respective long-term mean abundances, allowing the identification of major and minor blooms. Sixty-five percent of blooms identified at Newport Beach coincided with measurable DA concentrations, while 36 % of blooms at Redondo Beach coincided with measurable DA. Bloom definitions allowed for increased specificity in multiple regression analysis of environmental forcing factors significant to the presence of DA and P. seriata. The strongest relationship identified was between P. seriata abundances 2 weeks following upwelling events at Newport Beach. © 2012 Springer-Verlag Berlin Heidelberg.

Impact of multispecies diatom bloom on plankton community structure in Sundarban mangrove wetland, India

International Nuclear Information System (INIS)

Biswas, Sejuti Naha; Rakshit, Dibyendu; Sarkar, Santosh Kumar; Sarangi, Ranjit Kumar; Satpathy, Kamala Kanta

2014-01-01

Highlights: • A multispecies algal bloom was studied in coastal regions of Sundarban wetland. • Sharp changes in plankton community structure and hydrological parameters observed. • Chlorophyll a showed highest cell density (11.4 × 10 5 cells l −1 ) during bloom phase. • MODIS Aqua derived chlorophyll maps have been interpreted. - Abstract: A multispecies bloom caused by the centric diatoms, viz. Coscinodiscus radiatus, Chaetoceros lorenzianus and the pennate diatom Thalassiothrix frauenfeldii was investigated in the context of its impact on phytoplankton and microzooplankton (the loricate ciliate tintinnids) in the coastal regions of Sagar Island, the western part of Sundarban mangrove wetland, India. Both number (15–18 species) and cell densities (12.3 × 10 3 cells l −1 to 11.4 × 10 5 cells l −1 ) of phytoplankton species increased during peak bloom phase, exhibiting moderately high species diversity (H′ = 2.86), richness (R′ = 6.38) and evenness (E′ = 0.80). The diatom bloom, which existed for a week, had a negative impact on the tintinnid community in terms of drastic changes in species diversity index (1.09–0.004) and population density (582.5 × 10 3 to 50 × 10 3 ind m −3 ). The bloom is suggested to have been driven by the aquaculture activities and river effluents resulting high nutrient concentrations in this region. An attempt has been made to correlate the satellite remote sensing-derived information to the bloom conditions. MODIS-Aqua derived chlorophyll maps have been interpreted

Economic Cost of an Algae Bloom Cleanup in China's 2008 Olympic Sailing Venue

Science.gov (United States)

Wang, X. H.; Li, L.; Bao, X.; Zhao, L. D.

2009-07-01

In the summer of 2008, an algae bloom struck the coast of Qingdao, China, where the 2008 Olympic sailing events were to be held. The bloom was caused by the drift and proliferation of the green algae Enteromorpha (see http://precedings.nature.com/documents/2352/version/1). It lasted for more than 1 month and covered nearly the entire sailing venue. The Enteromorpha bloom was so intense that national and local governments invested a tremendous amount of labor and resources in a cleanup effort in order to achieve Olympic Games standards [Hu and He, 2008].

State of knowledge and concerns on cyanobacterial blooms and cyanotoxins.

Science.gov (United States)

Merel, Sylvain; Walker, David; Chicana, Ruth; Snyder, Shane; Baurès, Estelle; Thomas, Olivier

2013-09-01

Cyanobacteria are ubiquitous microorganisms considered as important contributors to the formation of Earth's atmosphere and nitrogen fixation. However, they are also frequently associated with toxic blooms. Indeed, the wide range of hepatotoxins, neurotoxins and dermatotoxins synthesized by these bacteria is a growing environmental and public health concern. This paper provides a state of the art on the occurrence and management of harmful cyanobacterial blooms in surface and drinking water, including economic impacts and research needs. Cyanobacterial blooms usually occur according to a combination of environmental factors e.g., nutrient concentration, water temperature, light intensity, salinity, water movement, stagnation and residence time, as well as several other variables. These environmental variables, in turn, have promoted the evolution and biosynthesis of strain-specific, gene-controlled metabolites (cyanotoxins) that are often harmful to aquatic and terrestrial life, including humans. Cyanotoxins are primarily produced intracellularly during the exponential growth phase. Release of toxins into water can occur during cell death or senescence but can also be due to evolutionary-derived or environmentally-mediated circumstances such as allelopathy or relatively sudden nutrient limitation. Consequently, when cyanobacterial blooms occur in drinking water resources, treatment has to remove both cyanobacteria (avoiding cell lysis and subsequent toxin release) and aqueous cyanotoxins previously released. Cells are usually removed with limited lysis by physical processes such as clarification or membrane filtration. However, aqueous toxins are usually removed by both physical retention, through adsorption on activated carbon or reverse osmosis, and chemical oxidation, through ozonation or chlorination. While the efficient oxidation of the more common cyanotoxins (microcystin, cylindrospermopsin, anatoxin and saxitoxin) has been extensively reported, the chemical

Automatic Detection of Childhood Absence Epilepsy Seizures: Toward a Monitoring Device

DEFF Research Database (Denmark)

Duun-Henriksen, Jonas; Madsen, Rasmus E.; Remvig, Line S.

2012-01-01

Automatic detections of paroxysms in patients with childhood absence epilepsy have been neglected for several years. We acquire reliable detections using only a single-channel brainwave monitor, allowing for unobtrusive monitoring of antiepileptic drug effects. Ultimately we seek to obtain optimal...... long-term prognoses, balancing antiepileptic effects and side effects. The electroencephalographic appearance of paroxysms in childhood absence epilepsy is fairly homogeneous, making it feasible to develop patient-independent automatic detection. We implemented a state-of-the-art algorithm...

Cyanobacteria of the 2016 Lake Okeechobee and Okeechobee Waterway harmful algal bloom

Science.gov (United States)

Rosen, Barry H.; Davis, Timothy W.; Gobler, Christopher J.; Kramer, Benjamin J.; Loftin, Keith A.

2017-05-31

The Lake Okeechobee and the Okeechobee Waterway (Lake Okeechobee, the St. Lucie Canal and River, and the Caloosahatchee River) experienced an extensive harmful algal bloom within Lake Okeechobee, the St. Lucie Canal and River and the Caloosahatchee River in 2016. In addition to the very visible bloom of the cyanobacterium Microcystis aeruginosa, several other cyanobacteria were present. These other species were less conspicuous; however, they have the potential to produce a variety of cyanotoxins, including anatoxins, cylindrospermopsins, and saxitoxins, in addition to the microcystins commonly associated with Microcystis. Some of these species were found before, during, and 2 weeks after the large Microcystis bloom and could provide a better understanding of bloom dynamics and succession. This report provides photographic documentation and taxonomic assessment of the cyanobacteria present from Lake Okeechobee and the Caloosahatchee River and St. Lucie Canal, with samples collected June 1st from the Caloosahatchee River and Lake Okeechobee and in July from the St. Lucie Canal. The majority of the images were of live organisms, allowing their natural complement of pigmentation to be captured. The report provides a digital image-based taxonomic record of the Lake Okeechobee and the Okeechobee Waterway microscopic flora. It is anticipated that these images will facilitate current and future studies on this system, such as understanding the timing of cyanobacteria blooms and their potential toxin production.

Mesoscale Eddies Control the Timing of Spring Phytoplankton Blooms: A Case Study in the Japan Sea

Science.gov (United States)

Maúre, E. R.; Ishizaka, J.; Sukigara, C.; Mino, Y.; Aiki, H.; Matsuno, T.; Tomita, H.; Goes, J. I.; Gomes, H. R.

2017-11-01

Satellite Chlorophyll a (CHL) data were used to investigate the influence of mesoscale anticyclonic eddies (AEs) and cyclonic eddies (CEs) on the timing of spring phytoplankton bloom initiation around the Yamato Basin (133-139°E and 35-39.5°N) in the Japan Sea, for the period 2002-2011. The results showed significant differences between AEs and CEs in the timing and initiation mechanism of the spring phytoplankton bloom. Blooms were initiated earlier in CEs which were characterized by shallow mixed-layer depths (mixed-layer depth. Conversely, blooms appeared in the AEs despite deeper mixed-layer depth (> 100 m) but close to the commencement of positive Q0. This suggests that the relaxation of turbulent mixing is crucial for the bloom initiation in AEs.

Physical and biological data collected along the Texas, Mississippi, and Florida Gulf coasts in the Gulf of Mexico as part of the Harmful Algal BloomS Observing System from 19 Aug 1953 to 11 July 2014 (NODC Accession 0120767)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — HABSOS (Harmful Algal BloomS Observing System) is a data collection and distribution system for harmful algal bloom (HAB) information in the Gulf of Mexico. The goal...

Fungal parasitism: life cycle, dynamics and impact on cyanobacterial blooms.

Directory of Open Access Journals (Sweden)

Mélanie Gerphagnon

Full Text Available Many species of phytoplankton are susceptible to parasitism by fungi from the phylum Chytridiomycota (i.e. chytrids. However, few studies have reported the effects of fungal parasites on filamentous cyanobacterial blooms. To investigate the missing components of bloom ecosystems, we examined an entire field bloom of the cyanobacterium Anabaena macrospora for evidence of chytrid infection in a productive freshwater lake, using a high resolution sampling strategy. A. macrospora was infected by two species of the genus Rhizosiphon which have similar life cycles but differed in their infective regimes depending on the cellular niches offered by their host. R. crassum infected both vegetative cells and akinetes while R. akinetum infected only akinetes. A tentative reconstruction of the developmental stages suggested that the life cycle of R. crassum was completed in about 3 days. The infection affected 6% of total cells (and 4% of akinètes, spread over a maximum of 17% of the filaments of cyanobacteria, in which 60% of the cells could be parasitized. Furthermore, chytrids may reduce the length of filaments of Anabaena macrospora significantly by "mechanistic fragmentation" following infection. All these results suggest that chytrid parasitism is one of the driving factors involved in the decline of a cyanobacteria blooms, by direct mortality of parasitized cells and indirectly by the mechanistic fragmentation, which could weaken the resistance of A. macrospora to grazing.

The 1987–1989 Phytoplankton Bloom in Kaneohe Bay

Directory of Open Access Journals (Sweden)

Edward Laws

2018-06-01

Full Text Available A remarkable bloom of phytoplankton occurred in the southeast sector (SE of Kaneohe Bay from 1987 through 1989. During the bloom, concentrations of chlorophyll a at the former site of the Kaneohe municipal wastewater treatment plant outfall averaged a little more than 2 mg m–3 for a period of 40 months. The increase of chl a was accompanied by a roughly twofold increase in the percentage of chl a accounted for by cells retained on a 35-micron filter, a drawdown of silicate concentrations from roughly 10 μM to 3–4 μM, an increase of nitrate concentrations from roughly 0.5 to more than 3 μM, and an increase of phosphate concentrations from roughly 0.2 to 0.5 μM. Extraordinarily heavy rains on 31 December 1987 led to flooding and land runoff that briefly raised chl a concentrations in the bay to as high as 17 mg m–3, but the bloom in question developed more than one year before the 1987 New Year’s Eve flood. It was not caused by unusually heavy rainfall: the average rainfall during 1987–1989 was only 10% above the long-term average. Instead, the bloom appears to have been caused by a leak in the sanitary sewer line that was previously used to discharge secondary treated sewage into Kaneohe Bay. Ultimately, leaks in the sanitary sewer lines maintained by the City and County of Honolulu led to legal action and a consent decree that required upgrading and the renovation of the wastewater collection system.

Trichodesmium blooms and warm-core ocean surface features in the Arabian Sea and the Bay of Bengal.

Science.gov (United States)

Jyothibabu, R; Karnan, C; Jagadeesan, L; Arunpandi, N; Pandiarajan, R S; Muraleedharan, K R; Balachandran, K K

2017-08-15

Trichodesmium is a bloom-forming, diazotrophic, non-heterocystous cyanobacteria widely distributed in the warmer oceans, and their bloom is considered a 'biological indication' of stratification and nitrogen limitation in the ocean surface layer. In the first part of this paper, based on the retrospective analyses of the ocean surface mesoscale features associated with 59 Trichodesmium bloom incidences recorded in the past, 32 from the Arabian Sea and the Bay of Bengal, and 27 from the rest of the world, we have showed that warm-core features have an inducing effect on bloom formation. In the second part, we have considered the environmental preferences of Trichodesmium bloom based on laboratory and field studies across the globe, and proposed a view about how warm-core features could provide an inducing pre-requisite condition for the bloom formation in the Arabian Sea and the Bay of Bengal. Proposed that the subsurface waters of warm-core features maintain more likely chances for the conducive nutrient and light conditions required for the triggering of the blooms. Copyright © 2017 Elsevier Ltd. All rights reserved.

Cyanotoxin mixtures and taste-and-odor compounds in cyanobacterial blooms from the midwestern united states

Science.gov (United States)

Graham, J.L.; Loftin, K.A.; Meyer, M.T.; Ziegler, A.C.

2010-01-01

The mixtures of toxins and taste-and-odor compounds present during cyanobacterial blooms are not well characterized and of particular concern when evaluating potential human health risks. Cyanobacterial blooms were sampled in twenty-three Midwestern United States lakes and analyzed for community composition, thirteen cyanotoxins by liquid chromatography/mass spectrometry and immunoassay, and two taste-and-odor compounds by gas chromatography/mass spectrometry. Aphanizomenon, Cylindrospermopsis and/or Microcystis were dominant in most (96%) blooms, but community composition was not strongly correlated with toxin and taste-and-odor occurrence. Microcystins occurred in all blooms. Total microcystin concentrations measured by liquid chromatography/mass spectrometry and immunoassay were linearly related (rs = 0.76, p cyanotoxins occurred in 48% of blooms and 95% had multiple microcystin variants. Toxins and taste-and-odor compounds frequently co-occurred (91% of blooms), indicating odor may serve as a warning that cyanotoxins likely are present. However, toxins occurred more frequently than taste-and-odor compounds, so odor alone does not provide sufficient warning to ensure human-health protection. ?? This article not subject to U.S. Copyright. Published 2010 by the American Chemical Society.

Extensive Chaetoceros curvisetus bloom in relation to water quality in Port Blair Bay, Andaman Islands.

Science.gov (United States)

Begum, Mehmuna; Sahu, Biraja Kumar; Das, Apurba Kumar; Vinithkumar, Nambali Valsalan; Kirubagaran, Ramalingam

2015-05-01

Blooming of diatom species Chaetoceros curvisetus (Cleve, 1889) was observed in Junglighat Bay and Haddo Harbour of Port Blair Bay of Andaman and Nicobar Islands during June 2010. Physico-chemical parameters, nutrient concentrations and phytoplankton composition data collected from five stations during 2010 were classified as bloom area (BA) and non-bloom area (NBA) and compared. Elevated values of dissolved oxygen were recorded in the BA, and it significantly varied (p NBA. Among the nutrient parameters studied, nitrate concentration indicated significant variation in BA and NBA (p NBA, indicating its utilization. In Junglighat Bay, the C. curvisetus species constituted 93.4 and 69.2% composition of total phytoplankton population during day 1 and day 2, respectively. The bloom forming stations separated out from the non-bloom forming station in non-parametric multidimensional scaling (nMDS) ordinations; cluster analysis powered by SIMPROF test also grouped the stations as BA and NBA.

An Automatic Monitoring System for High-Frequency Measuring and Real-Time Management of Cyanobacterial Blooms in Urban Water Bodies

Directory of Open Access Journals (Sweden)

Viet Tran Khac

2018-01-01

Full Text Available Urban lakes mitigate the negative impacts on the hydrological cycle and improve the quality of life in cities. Worldwide, the concern increases for the protection and management of urban water bodies. Since the physical-chemical and biological conditions of a small aquatic ecosystem can vary rapidly over time, traditional low frequency measurement approaches (weekly or monthly sampling limits the knowledge and the transfer of research outcomes to management decision-making. In this context, this paper presents an automatic monitoring system including a full-scale experimental site and a data transfer platform for high-frequency observations (every 5 min in a small and shallow urban lake (Lake Champs-sur-Marne, Paris, France, 10.3 ha. Lake stratification and mixing periods can be clearly observed, these periods are compared with the dynamic patterns of chlorophyll-a, phycocyanin, dissolved oxygen and pH. The results indicate that the phytoplankton growth corresponds with dissolved oxygen cycles. However, thermal stratification cannot totally explain the entire dynamic patterns of different physical-chemical and ecological variables. Besides, the cyanobacteria is one of the dominating groups of phytoplankton blooms during the lake stratification periods (8 August–29 September 2016. During the cooling mixed period (29 September–19 October 2016, the high concentration of chlorophyll-a is mainly caused by the other phytoplankton species, such as diatoms. Perspectives are discussed in order to apply this observation system for real-time management of water bodies and lakes.

The detection of wind turbine shaft misalignment using temperature monitoring

OpenAIRE

Tonks, Oliver; Wang, Qing

2016-01-01

Temperature is a parameter increasingly monitored in wind turbine systems. This paper details a potential temperature monitoring technique for use on shaft couplings. Such condition monitoring methods aid fault detection in other areas of wind turbines. However, application to shaft couplings has not previously been widely researched. A novel temperature measurement technique is outlined, using an infra-red thermometer which can be applied to online condition monitoring. The method was va...

Improving microcystin monitoring relevance in recreative waters: A regional case-study (Brittany, Western France, Europe).

Science.gov (United States)

Pitois, Frédéric; Vezie, Chantal; Thoraval, Isabelle; Baurès, Estelle

2016-05-01

Cyanobacteria and their toxins are known as a health hazard in recreative and distributed waters. Monitoring data from 2004 to 2011 were collected at regional scale to characterize exposition parameters to microcystins in Brittany (Western France). The data show that cyanobacteria populations are experiencing a composition shift leading to a longer duration of cell densities higher than WHO alert levels 2 and 3. Microcystins however appear to be more frequently detected with subacute concentrations in low cell density samples than in high cell density samples or during bloom episodes. Positive relations are described between microcystin concentrations, detection frequencies and cyanobacteria biovolumes, allowing for a novel definition of alert levels and decision framework following WHO recommendations. Copyright © 2015 Elsevier GmbH. All rights reserved.

Toxic cyanobacteria strains isolated from blooms in the Guadiana River (southwestern Spain

Directory of Open Access Journals (Sweden)

ISABEL M MORENO

2004-01-01

Full Text Available This paper describes the occurrence of toxic cyanobacteria along the Guadiana River over its course between Mérida and Badajoz (Extremadura, Spain. Water sampling for phytoplankton quantification and toxin analysis was carried out regularly between 1999 and 2001 in six different locations, including two shallow, slow-flowing river sites, two streamed river sites and two drinking water reservoirs. The cyanobacterial community differed significantly between these locations, especially during the summer. The predominant genera were Microcystis, Oscillatoria, Aphanizomenon and Anabaena. Using an ELISA assay the total microcystin contents of natural water samples from the most eutrophic locations ranged from 0.10 _ 21.86 mg mcyst-LR equivalent·L-1 in Valdelacalzada and 0.10-11.3 µg mcyst-LR equivalent·L-1 in Vitonogales, and a seasonal variation of toxin content was observed. The amount of microcystins produced by each strain was determined by ELISA assay and the detection and identification of microcystin variants of three toxic strains of Microcystis aeruginosa was performed by high performance liquid chromatography (HPLC. The analysis of microcystins of the cultured strains revealed that toxin production was variable among different strains of M. aeruginosa isolated either from different blooms or from the same bloom.

Advanced characterization of dissolved organic matter released by bloom-forming marine algae

KAUST Repository

Rehman, Zahid Ur

2017-06-01

Algal organic matter (AOM), produced by marine phytoplankton during bloom periods, may adversely affect the performance of membrane processes in seawater desalination. The polysaccharide fraction of AOM has been related to (bio)fouling in micro-filtration and ultrafiltration, and reverse osmosis membranes. However, so far, the chemical structure of the polysaccharides released by bloom-forming algae is not well understood. In this study, dissolved fraction of AOM produced by three algal species (Chaetoceros affinis, Nitzschia epithemoides and Hymenomonas spp.) was characterized using liquid chromatography–organic carbon detection (LC-OCD) and fluorescence spectroscopy. Chemical structure of polysaccharides isolated from the AOM solutions at stationary phase was analyzed using proton nuclear magnetic resonance (H-NMR). The results showed that production and composition of dissolved AOM varied depending on algal species and their growth stage. AOM was mainly composed of biopolymers (BP; i.e., polysaccharides and proteins [PN]), but some refractory substances were also present.H-NMR spectra confirmed the predominance of carbohydrates in all samples. Furthermore, similar fingerprints were observed for polysaccharides of two diatom species, which differed considerably from that of coccolithophores. Based on the findings of this study,H-NMR could be used as a method for analyzing chemical profiles of algal polysaccharides to enhance the understanding of their impact on membrane fouling.

The impact of habitat conditions on blooming of Helichrysum arenarium (L. Moench

Directory of Open Access Journals (Sweden)

Anna K. Sawilska

2012-12-01

Full Text Available Helichrysum arenarium (L. Moench is a perennial belonging to the Asteraceae family. It is used as a herb material. The species is under partial protection. The aim of the study was to determine the influence of the community type and weather conditions on blooming of everlasting. Growth and development dynamics vs. habitat factors were analyzed in detail. The results of this study indicate that blooming process of everlasting populations remains under influence of habitat factors, which is evidenced by a decrease of potential fertility paralleled by an increase of number of taxa found in phytocoenosis. Blooming process is also modified by weather conditions: the potential fertility index is significantly correlated with precipitation.

The sedimentary record of dinoflagellate cysts: looking back into the future of phytoplankton blooms

Directory of Open Access Journals (Sweden)

Barrie Dale

2001-12-01

Full Text Available Marine systems are not as well understood as terrestrial systems, and there is still a great need for more primary observations, in the tradition of the old-time naturalists, before newer methods such as molecular genetics and modeling can be fully utilized. The scientific process whereby the smaller, detailed building blocks of observation are ultimately linked towards better understanding natural systems is illustrated from my own career experience, especially with regard to the dinoflagellates and plankton blooms. Some dinoflagellates produce a fossilizable resting stage (cyst in their life cycle, and dinoflagellate cysts have become one of the most important groups of microfossils used in geological exploration (e.g. oil and gas. This has stimulated both paleontological and biological research producing detailed building blocks of information, currently scattered throughout the respective literature. Here, I attempt to bring together the present day perspective, from biology, with the past, from paleontology, as the most comprehensive basis for future work on the group. This shows the cysts to be the critical link needed for focusing future molecular genetics studies towards a more verifiable view of evolutionary pathways, and it also suggests new integrated methods for studying past, present, and future blooms. The large, rapidly growing field of harmful algal bloom studies is producing many different building blocks, but plankton blooms as episodic phenomena are still poorly understood. This is largely due to the general lack of long-term datasets allowing identification of the changing environmental factors that permit certain species to bloom at unpredictable intervals of time. Cysts in sediments are useful environmental indicators today, e.g. reflecting aspects of climate and pollution, and provide information directly relevant to some dinoflagellate blooms. They therefore may be used for obtaining retrospective information from the

An Improved Thermal Blooming Model for the Laser Performance Code Anchor

Science.gov (United States)

2016-06-01

over which a laser beam can maintain transverse coherence throughout its propagation distance. Typical values of ro are on the order of a few...G. Gebhardt, “Twenty-five years of thermal blooming: An overview,” in Proceedings of SPIE 1221 Propagation of High-Energy Laser Beams Through the...TERMS thermal blooming, atmospheric propagation , laser , scaling code, Strehl ratio, ANCHOR, COAMPS, NAVSLaM, LEEDR 15. NUMBER OF PAGES 77 16

Long-range alpha detection applied to soil contamination and waste monitoring

International Nuclear Information System (INIS)

MacArthur, D.W.; Allander, K.S.; Bounds, J.A.; Close, D.A.; McAtee, J.L.

1992-01-01

Alpha contamination monitoring has been traditionally limited by the short range of alpha particles in air and through detector windows. The long-range alpha detector (LRAD) described in this paper circumvents that limitation by detecting alpha-produced ions, rather than alpha particles directly. Since the LRAD is sensitive to all ions, it can monitor all contamination present on a large surface at one time. Because air is the ''detector gas,'' the LRAD can detect contamination on any surface to which air can penetrate. We present data showing the sensitivity of LRAD detectors, as well as documenting their ability to detect alpha sources in previously unmonitorable locations, and verifying the ion lifetime. Specific designs and results for soil contamination and waste monitors are also included

SCALABLE TIME SERIES CHANGE DETECTION FOR BIOMASS MONITORING USING GAUSSIAN PROCESS

Data.gov (United States)

National Aeronautics and Space Administration — SCALABLE TIME SERIES CHANGE DETECTION FOR BIOMASS MONITORING USING GAUSSIAN PROCESS VARUN CHANDOLA AND RANGA RAJU VATSAVAI Abstract. Biomass monitoring,...

Mycosporine-like amino acids and xanthophyll-cycle pigments favour a massive spring bloom development of the dinoflagellate Prorocentrum minimum in Grande Bay (Argentina), an ozone hole affected area

Science.gov (United States)

Carreto, José I.; Carignan, Mario O.; Montoya, Nora G.; Cozzolino, Ezequiel; Akselman, Rut

2018-02-01

In Grande Bay (Southern Patagonian Shelf) in a eutrophic and recirculating area slightly stratified during spring, we observed an intense (up to 1 × 107 cells L- 1) and shallow, quasi mono-specific bloom of the dinoflagellate Prorocentrum minimum. Peridinin was the most abundant carotenoid, but the relative amounts of the xanthophyll cycle carotenoids (diadinoxanthin + diatoxanthin = DT) to light-harvesting pigments were high (DT/Chl a ratio = 0.32 and DT/peridinin ratio = 0.40). Shinorine, usujirene, palythene, mycosporine-serine-glycine methyl ester and palythenic acid were the primary mycosporine-like amino acids (MAAs), followed by mycosporine-glycine, palythine, and porphyra-334. The ΣMAAs/Chl a ratios (up to 27.9 nmol/nmol) were in the upper range reported either in nutrient-replete dinoflagellate cultures or natural populations. We monitored, from space (using satellite ocean colour data), the spatial and temporal bloom variability (from September 22 to October 31, 2005) using an approach to discriminate dinoflagellate from diatom blooms. The results indicated that an intense diatom bloom started in early spring but was rapidly replaced by an intense bloom of the dinoflagellate P. minimum, although the nutrient concentrations were apparently not limiting. The most notorious change in this period was a sharp increase in the levels of solar UVB radiation (UVB index 9.0) as a consequence of the overpass of the polar vortex over this area. We postulated that the synthesis and accumulation of MAAs and xanthophyll pigments, were competitive advantages for the opportunistic red tide dinoflagellate P. minimum over the sensitive diatoms, favouring the development of their surface blooms in this seasonally solar UVB radiation (UVBR) affected area.

A new insight into black blooms: Synergies between optical and chemical factors

Science.gov (United States)

Duan, Hongtao; Loiselle, Steven Arthur; Li, Zuochen; Shen, Qiushi; Du, Yingxun; Ma, Ronghua

2016-06-01

Black blooms have been associated with fish-kills and the loss of benthic fauna as well as closure of potable water supplies. Their frequency and duration has increased in recent decades in rivers, inland lakes and reservoirs, and has often been associated with the decay and release of organic matter (planktonic algae, aquatic macrophytes, sediment release, etc.). However, the interactions between microbial, chemical, hydrodynamic and optical conditions necessary for black blooms are poorly understood. The present study combines field investigations and laboratory mesocosm studies to show that black blooms are caused by a combination of high CDOM (chromophoric dissolved organic matter) absorption, the formation of CDOM-Fe complexes and low backscattering. Mesocosm experiments showed that black bloom conditions occur after 4 days, with a significant increase in the concentrations of Fe2+ and ∑S2-. Total absorption (excluding absorption due to water) at 440 nm increased by 30% over this time to 7.3 m-1. In addition, the relative contribution of CDOM absorption to the non-water total absorption increased from 18% to 50%. Regression analyses between chemical and bio-optical data in both field and mesocosm experiments indicated that the concentrations of Fe2+ co-varied positively with CDOM absorption ag(440) (R2 > 0.70), and the specific CDOM absorption (ag(440)/DOC). Conditions that favored the development of black blooms were elevated algal or macrophyte biomass and limited water column mixing.

Factors controlling the development of phytoplankton blooms in the Antarctic Ocean

International Nuclear Information System (INIS)

Sakshaug, Egil; Holm-Hansen, Osmund

1991-01-01

A mathematical model describing the development of phytoplankton blooms as a function of the depth of the wind-mixed layer, spectral distribution of light, passage of atmospheric low-pressure systems, size of the initial phytoplankton stock and loss rates is presented. Model runs represent shade-adapted, large-celled, bloom-forming diatoms Periodic deep mixing caused by strong winds may severely retard the development of blooms and frequently abort them before macronutrients are completely exhausted. Moderate depths of mixing (40-50 m) in combination with a moderately large total loss rate (about 0.013h -1 ) can prevent blooms from developing during the brightest time of the year. Complete exhaustion of macronutrients in the upper waters is likely only if the wind-mixed layer is less than 10 m deep, i.e. in very sheltered waters, and also in the marginal ice zone when ice is melting. The authors do not exclude the possibility of control of phytoplankton biomass by iron in ice-free, deep-sea parts of the Antarctic Ocean, but the implied enhancement of export production through addition of iron might be restricted because of limitation by light, i.e. vertical mixing. (author). 32 ref.; 5 figs.; 2 tabs

Bloom Dynamics of Cyanobacteria and Their Toxins: Environmental Health Impacts and Mitigation Strategies

Science.gov (United States)

Rastogi, Rajesh P.; Madamwar, Datta; Incharoensakdi, Aran

2015-01-01

Cyanobacteria are ecologically one of the most prolific groups of phototrophic prokaryotes in both marine and freshwater habitats. Both the beneficial and detrimental aspects of cyanobacteria are of considerable significance. They are important primary producers as well as an immense source of several secondary products, including an array of toxic compounds known as cyanotoxins. Abundant growth of cyanobacteria in freshwater, estuarine, and coastal ecosystems due to increased anthropogenic eutrophication and global climate change has created serious concern toward harmful bloom formation and surface water contamination all over the world. Cyanobacterial blooms and the accumulation of several cyanotoxins in water bodies pose severe ecological consequences with high risk to aquatic organisms and global public health. The proper management for mitigating the worldwide incidence of toxic cyanobacterial blooms is crucial for maintenance and sustainable development of functional ecosystems. Here, we emphasize the emerging information on the cyanobacterial bloom dynamics, toxicology of major groups of cyanotoxins, as well as a perspective and integrative approach to their management. PMID:26635737

Growth monitoring as an early detection tool: a systematic review

NARCIS (Netherlands)

Scherdel, P.; Dunkel, L.; Dommelen, P. van; Goulet, O.; Salaün, J.F.; Brauner, R.; Heude, B.; Chalumeau, M.

2016-01-01

Growth monitoring of apparently healthy children aims at early detection of serious underlying disorders. However, existing growth-monitoring practices are mainly based on suboptimal methods, which can result in delayed diagnosis of severe diseases and inappropriate referrals. We did a systematic

Microplanktonic community structure in a coastal system relative to a Phaeocystis bloom inferred from morphological and tag pyrosequencing methods.

Directory of Open Access Journals (Sweden)

Sébastien Monchy

Full Text Available BACKGROUND: Massive phytoplankton blooms, like the recurrent Phaeocystis proliferation observed every year in the Eastern English Channel (EEC, have a significant influence on the overall planktonic community structure and their food web dynamics. As well as being an important area for local fisheries, the EEC is an ideal ecosystem for work on microbial diversity. This is because, although its environmental context is relatively complex, it is reasonably well understood due to several years of monitoring and morphological observations of its planktonic organisms. The objective of our study was to better understand the under-explored microbial eukaryotic diversity relative to the Phaeocystis bloom. METHODOLOGY AND PRINCIPAL FINDINGS: The community structure of microplankton (diatoms, haptophytes, ciliates and dinoflagellates was studied through morphological observations and tag pyrosequencing. During the annual Phaeocystis spring bloom, the phytoplankton biomass increased by 34-fold, while the microzooplankton biomass showed a 4-fold increase, representing on average about 4.6% of the biomass of their phytoplankton prey. Tag pyrosequencing unveiled an extensive diversity of Gymnodiniaceae, with G. spirale and G. fusiformis representing the most abundant reads. An extended diversity of Phaeocystales, with partial 18S rDNA genes sequence identity as low as 85% was found, with taxa corresponding to P. globosa, but also to unknown Phaeocystaceae. CONCLUSIONS: Morphological analyses and pyrosequencing were generally in accordance with capturing frequency shifts of abundant taxa. Tag pyrosequencing allowed highlighting the maintenance of microplankton diversity during the Phaeocystis bloom and the increase of the taxa presenting low number of reads (minor taxa along with the dominant ones in response to biotic and/or abiotic changing conditions. Although molecular approaches have enhanced our perception on diversity, it has come to light that the

The bloom of the dinoflagellate (Noctiluca miliaris) in the North Eastern Arabian Sea: Ship and Satellite study

Digital Repository Service at National Institute of Oceanography (India)

Matondkar, S.G.P.; Basu, S.; Parab, S.G.; Pednekar, S.; Dwivedi, R.M.; Raman, M.; Goes, J.I.; Gomes, H.

The bloom of Noctiluca miliaris (a dinoflagellate) which appears in the form of a green tide was studied from 2003-2011. This bloom covered a large area of the Arabian Sea from the west coast of India to the coast of Oman. The bloom was easily...

Selective grazing of Temora longicornis in different stages of a Phaeocystis globosa bloom - a mesocosm study

DEFF Research Database (Denmark)

Koski, Marja; Dutz, Jörg; Breteler, W.C.M.K.

2005-01-01

changes during the initiation, maintenance, collapse and decay of a P. globosa bloom and (3) if P. globosa dominated food assemblage provides a good diet for copepod egg production. Our results show low but constant feeding on small colonies of P. globosa, irrespective of the type or concentration...... of alternative food sources. In contrast, feeding on single cells was never significant, and the total contribution of P globosa to carbon ingestion of T longicornis was minor. T longicornis fed most actively on the decaying colonies, whereas during the peak of the bloom copepods selected against P globosa....... Mostly, T longicornis fed unselectively on different food particles: before the bloom, the major part of the diet consisted of diatoms, whereas during and after the bloom copepod diet was dominated by dinoflagellates and ciliates. Egg production was highest during the decay of the bloom, coinciding...

A Fluorescence Based Miniaturized Detection Module for Toxin Producing Algae

Science.gov (United States)

Zieger, S. E.; Mistlberger, G.; Troi, L.; Lang, A.; Holly, C.; Klimant, I.

2016-12-01

Algal blooms are sensitive to external environmental conditions and may pose a serious threat to marine and human life having an adverse effect on the ecosystem. Harmful algal blooms can produce different toxins, which can lead to massive fish kills or to human disorders. Facing these problems, miniaturized and low-cost instrumentation for an early detection and identification of harmful algae classes has become more important over the last years. 1,2Based on the characteristic pigment pattern of different algae classes, we developed a miniaturized detection module, which is able to detect and identify algae classes after analyzing their spectral behavior. Our device combines features of a flow-cytometer and fluorimeter and is build up as a miniaturized and low-cost device of modular design. Similar to a fluorimeter, it excites cells in the capillary with up to 8 different excitation wavelengths recording the emitted fluorescence at 4 different emission channels. Furthermore, the device operates in a flow-through mode similar to a flow-cytometer, however, using only low-cost elements such as LEDs and photodiodes. Due to its miniaturized design, the sensitivity and selectivity increase, whereas background effects are reduced. With a sampling frequency of 140 Hz, we try to detect and count particular cell events even at a concentration of 2 cells / 7.3 µL illuminated volume. Using a self-learning multivariate algorithm, the data are evaluated autonomously on the device enabling an in-situ analysis. The flexibility in choosing excitation and emission wavelengths as well as the high sampling rate enables laboratory applications such as measuring induction kinetics. However, in its first application, the device is part of an open and modular monitoring system enabling the sensing of chemical compounds such as toxic and essential Hg, Cd, Pb, As and Cu trace metal species, nutrients and species related to the carbon cycle, VOCs and potentially toxic algae classes (FP7

Beach-goer behavior during a retrospectively detected algal ...

Science.gov (United States)

Algal blooms occur among nutrient rich, warm surface waters and may adversely impact recreational beaches. During July – September 2003, a prospective study of beachgoers was conducted on weekends at a public beach on a Great Lake in the United States. We measured each beachgoer’s activity at the start and end of their beach visit and the environmental factors: water and air temperature, wind speed and wave height at the study site each day. At the time, there was no notification of algal blooms; we retrospectively evaluated the presence of algal blooms using MERIS data from the Envisat-1 satellite. A total of 2840 people participated in the study over 16 study days. The majority (55%) were female, and 751 (26%) were < 18 years of age. An algal bloom was detected retrospectively by remotely sensed satellite imagery during August 16 – 24. This peak bloom period (PB) included 4 study days. During PB study days, more study participants 226/742 (31%) reported body contact with the water compared to contact 531/2098 (25%) on non-peak days. During the 4 PB days, of the environmental factors, only mean water temperature was significantly different, 250 C vs. 230 C (p<0.05) from other days.These results suggest that beachgoer body contact with water was not deterred by the presence of an algal bloom, and that interventions to actively discourage water contact during a bloom are needed to reduce exposure to blooms. This is an abstract of a proposed presentation and

The history of cyanobacterial blooms in the Baltic Sea.

Science.gov (United States)

Finni, T; Kononen, K; Olsonen, R; Wallström, K

2001-08-01

Long-term information on possible changes in cyanobacterial blooms in the Baltic Sea, formed mainly by Nodularia spumigena and Aphanizomenon sp., was sought in published records in historical (years 1887-1938) and modern (years 1974-1998) phytoplankton data sets. Old and new sampling methods and fixatives were tested to improve the comparison of data that had been collected and analyzed in different ways. A hundred years ago, plankton was mainly of interest as a source of fish food; eutrophication problems were only locally reported from the coast, mainly in southern haffs and the receiving waters of larger cities. There were few recordings of open-sea blooms before World War II. Abundances of Nodularia spumigena and Aphanizomenon sp. were low in the old material, and 137 summer samples from 1887-1938 showed no peak abundance. High abundances are common in the new material, and the range of the numbers of both taxa has increased markedly relative to the old material. Since the 1960s, cyanobacterial blooms have been common in the open sea in both the Baltic proper and the Gulf of Finland, indicating high availability of nutrients.

Cyanobacterial bloom in the world largest freshwater lake Baikal

Science.gov (United States)

Namsaraev, Zorigto; Melnikova, Anna; Ivanov, Vasiliy; Komova, Anastasia; Teslyuk, Anton

2018-02-01

Lake Baikal is a UNESCO World Heritage Site and holds 20% of the world’s freshwater reserves. On July 26, 2016, a cyanobacterial bloom of a green colour a few kilometers in size with a bad odor was discovered by local people in the Barguzinsky Bay on the eastern shore of Lake Baikal. Our study showed very high concentration of chlorophyll a (41.7 g/m3) in the sample of bloom. We found that the bloom was dominated by a nitrogen-fixing heterocystous cyanobacteria of the genus Dolichospermum. The mass accumulation of cyanobacteria in the lake water with an extremely high chlorophyll a concentration can be explained by a combination of several factors: the discharge of biologicaly-available nutrients, including phosphorus, into the water of Lake Baikal; low wind speed and weak water mixing; buoyant cyanobacterial cells on the lake surface, which drifted towards the eastern coast, where the maximum concentration of chlorophyll a was recorded. In the center of the Barguzinsky Bay and in the open part of Lake Baikal, according to satellite data, the chlorophyll a concentration is several orders of magnitude lower than at the shoreline.

Dissection of Microbial Community Functions during a Cyanobacterial Bloom in the Baltic Sea via Metatranscriptomics

Directory of Open Access Journals (Sweden)

Carlo Berg

2018-02-01

Full Text Available Marine and brackish surface waters are highly dynamic habitats that undergo repeated seasonal variations in microbial community composition and function throughout time. While succession of the various microbial groups has been well investigated, little is known about the underlying gene-expression of the microbial community. We investigated microbial interactions via metatranscriptomics over a spring to fall seasonal cycle in the brackish Baltic Sea surface waters, a temperate brackish water ecosystem periodically promoting massive cyanobacterial blooms, which have implications for primary production, nutrient cycling, and expansion of hypoxic zones. Network analysis of the gene expression of all microbes from 0.22 to 200 μm in size and of the major taxonomic groups dissected the seasonal cycle into four components that comprised genes peaking during different periods of the bloom. Photoautotrophic nitrogen-fixing Cyanobacteria displayed the highest connectivity among the microbes, in contrast to chemoautotrophic ammonia-oxidizing Thaumarchaeota, while heterotrophs dominated connectivity among pre- and post-bloom peaking genes. The network was also composed of distinct functional connectivities, with an early season balance between carbon metabolism and ATP synthesis shifting to a dominance of ATP synthesis during the bloom, while carbon degradation, specifically through the glyoxylate shunt, characterized the post-bloom period, driven by Alphaproteobacteria as well as by Gammaproteobacteria of the SAR86 and SAR92 clusters. Our study stresses the exceptionally strong biotic driving force executed by cyanobacterial blooms on associated microbial communities in the Baltic Sea and highlights the impact cyanobacterial blooms have on functional microbial community composition.

Signal processing for solar array monitoring, fault detection, and optimization

CERN Document Server

Braun, Henry; Spanias, Andreas

2012-01-01

Although the solar energy industry has experienced rapid growth recently, high-level management of photovoltaic (PV) arrays has remained an open problem. As sensing and monitoring technology continues to improve, there is an opportunity to deploy sensors in PV arrays in order to improve their management. In this book, we examine the potential role of sensing and monitoring technology in a PV context, focusing on the areas of fault detection, topology optimization, and performance evaluation/data visualization. First, several types of commonly occurring PV array faults are considered and detection algorithms are described. Next, the potential for dynamic optimization of an array's topology is discussed, with a focus on mitigation of fault conditions and optimization of power output under non-fault conditions. Finally, monitoring system design considerations such as type and accuracy of measurements, sampling rate, and communication protocols are considered. It is our hope that the benefits of monitoring presen...

Uma visão interdisciplinar integrada da Taxonomia de Bloom

OpenAIRE

Trindade, José Pedro; Bahia, Sara; Mucharreira, Pedro Ribeiro

2015-01-01

Objetivos: Exemplificar uma aplicação da Taxonomia de Bloom numa atividade interdisciplinar numa escola do ensino privado em Lisboa e avaliar a sua eficácia. Fundamentação: A taxonomia revista de Bloom (Krathwohl, 2002) refere-se a conhecimentos de factos, conceitos, procedimentos e metacognitivos e desenvolve-se a partir da memorização, compreensão e aplicação, até à análise, avaliação e criação. No presente estudo, esta taxonomia procura consubstanciar uma linguagem comum par...

Benjamin Bloom: His Research and Influence on Education.

Science.gov (United States)

Anderson, Lorin W.

1988-01-01

A student of the University of Chicago's Measurement, Evaluation, and Statistical Analysis Program reflects upon Benjamin S. Bloom's professional and personal educational contributions, including mastery learning, educational equity, and educational excellence. (CB)

Blooming reduces the antioxidant capacity of dark chocolate in rats without lowering its capacity to improve lipid profiles.

Science.gov (United States)

Shadwell, Naomi; Villalobos, Fatima; Kern, Mark; Hong, Mee Young

2013-05-01

Dark chocolate contains high levels of antioxidants which are linked to a reduced risk of cardiovascular disease. Chocolate blooming occurs after exposure to high temperatures. Although bloomed chocolate is safe for human consumption, it is not known whether or not the biological function of bloomed chocolate is affected. We hypothesized that bloomed chocolate would reduce the antioxidant potential and lipid-lowering properties of chocolate through altered expression of related genes. Thirty Sprague-Dawley rats were divided into 3 groups and fed either the control (CON), regular dark chocolate (RDC), or bloomed dark chocolate (BDC) diet. After 3 weeks, serum lipid levels and antioxidant capacity were measured. Hepatic expression of key genes was determined by real time polymerase chain reaction (PCR). Sensory characteristics of bloomed versus regular chocolate were assessed in 28 semi-trained panelists. Rats fed RDC exhibited greater serum antioxidant capacities compared to the CON (P chocolate compared to bloomed chocolate (P chocolate, these results suggest that bloomed dark chocolate yields similarly beneficial effects on most blood lipid parameters or biomarkers. However, regular dark chocolate may be more beneficial for the improvement of antioxidant status and modulation of gene expression involved in lipid metabolism and promoted greater sensory ratings. Copyright © 2013 Elsevier Inc. All rights reserved.

Tsunamis detection, monitoring, and early-warning technologies

CERN Document Server

Joseph, Antony

2011-01-01

The devastating impacts of tsunamis have received increased focus since the Indian Ocean tsunami of 2004, the most devastating tsunami in over 400 years of recorded history. This professional reference is the first of its kind: it provides a globally inclusive review of the current state of tsunami detection technology and will be a much-needed resource for oceanographers and marine engineers working to upgrade and integrate their tsunami warning systems. It focuses on the two main tsunami warning systems (TWS): International and Regional. Featured are comparative assessments of detection, monitoring, and real-time reporting technologies. The challenges of detection through remote measuring stations are also addressed, as well as the historical and scientific aspects of tsunamis.

Detection and Processing Techniques of FECG Signal for Fetal Monitoring

Directory of Open Access Journals (Sweden)

Hasan MA

2009-03-01

Full Text Available Abstract Fetal electrocardiogram (FECG signal contains potentially precise information that could assist clinicians in making more appropriate and timely decisions during labor. The ultimate reason for the interest in FECG signal analysis is in clinical diagnosis and biomedical applications. The extraction and detection of the FECG signal from composite abdominal signals with powerful and advance methodologies are becoming very important requirements in fetal monitoring. The purpose of this review paper is to illustrate the various methodologies and developed algorithms on FECG signal detection and analysis to provide efficient and effective ways of understanding the FECG signal and its nature for fetal monitoring. A comparative study has been carried out to show the performance and accuracy of various methods of FECG signal analysis for fetal monitoring. Finally, this paper further focused some of the hardware implementations using electrical signals for monitoring the fetal heart rate. This paper opens up a passage for researchers, physicians, and end users to advocate an excellent understanding of FECG signal and its analysis procedures for fetal heart rate monitoring system.

Nitrogen and phosphorus requirements of an Alexandrium minutum bloom in the Penze' Estuary, France

Digital Repository Service at National Institute of Oceanography (India)

Maguer, J.-F.; Wafar, M.V.M.; Madec, C.; Morin, P.; Denn, E.E.

. The role of NO3 was restricted to sustenance of the bloom, whereas warm conditions resulting in a water column stability seem to have triggered the bloom, and a self-shading, probably coupled with a phosphorus limitation, caused its decline...

HIGH BREVETOXIN CONCENTRATIONS IN GYMNODINIUM BREVE BLOOMS ALONG THE NORTHWEST FLORIDA COAST DURING 1999.

Science.gov (United States)

Blooms of the dinoflagellate Gymnodinium breve (i.e. red tides) produce brevetoxins (PbTx) that negatively impact the Gulf of Mexico ecosystem, human health, and local economics. Characterizing and predicting bloom events and their impacts requires knowledge of G. breve abundance...

Oceanic and atmospheric influences on the variability of phytoplankton bloom in the southwestern Indian Ocean

Digital Repository Service at National Institute of Oceanography (India)

Raj, R.P.; Peter, B.N.; Pushpadas, D.

in the Mozambique Basin and inside the Mozambique Channel (MC). For a detailed inspection, we characterized the entire process of the development of this large dendritic bloom into two stages, early stage... period was in March. During 2001 and 2003, traces of the bloom (low concentration of chl-a) are observed in the MC and Mozambique Basin but not in the Madagascar basin. A weak bloom developed in the Madagascar Basin, Mozambique Basin and inside the MC...

Local Leak Detection and Health Monitoring of Pressurized Tanks

Science.gov (United States)

Polzin, Kurt; Witherow, William; Korman, Valentin; Sinko, John; Hendrickson, Adam

2011-01-01

An optical gas-detection sensor safely monitors pressurized systems (such as cryogenic tanks) and distribution systems for leaks. This sensor system is a fiber-coupled, solid optical body interferometer that allows for the miniaturized sensing element of the device to be placed in the smallest of recesses, and measures a wide range of gas species and densities (leaks). The deflection of the fringe pattern is detected and recorded to yield the time-varying gas density in the gap. This technology can be used by manufacturers or storage facilities with toxic, hazardous, or explosive gases. The approach is to monitor the change in the index of refraction associated with low-level gas leaks into a vacuum environment. The completion of this work will provide NASA with an enabling capability to detect gas system leaks in space, and to verify that pressurized systems are in a safe (i.e. non-leaking) condition during manned docking and transit operations. By recording the output of the sensor, a time-history of the leak can be constructed to indicate its severity. Project risk is mitigated by having several interferometric geometries and detection techniques available, each potentially leveraging hardware and lessons learned to enhance detectability.

Development of Phaeocystis globosa blooms in the upwelling waters of the South Central coast of Viet Nam

Science.gov (United States)

Hai, Doan-Nhu; Lam, Nguyen-Ngoc; Dippner, Joachim W.

2010-11-01

Blooms of haptophyte algae in the south central coastal waters of Viet Nam often occur in association with upwelling phenomenon during the southwest (SW) monsoon. Depending on the magnitude of the blooms, damage to aquaculture farms may occur. Based on two years of data on biology, oceanography, and marine chemistry, the present study suggests a conceptual model of the growth of the haptophyte Phaeocystis globosa. At the beginning of the bloom, low temperature and abundant nutrient supply, especially nitrate from rain and upwelling, favour bloom development. Diatoms utilize available nitrate and phosphate; subsequently, higher ammonium concentration allows P. globosa to grow faster than the diatoms. At the end of the Phaeocystis bloom, free cells may become available as food for a heterotrophic dinoflagellate species, Noctiluca scintillans. During and after the phytoplankton bloom, remineralization by bacteria reduces dissolved oxygen to a very low concentration at depth, and favors growth of nitrate-reducing bacteria.A Lagrangian Harmful Algal Bloom (HAB) model, driven by a circulation model of the area, realistically simulates the transport of microalgae in surface waters during strong and weak SW monsoon periods, suggesting that it may be a good tool for early warning of HABs in Vietnamese coastal waters.

The Internationalization of Bloom's Learning for Mastery: A 25-Year Retrospective-Prospective View.

Science.gov (United States)

Hymel, Glenn M.; Dyck, Walter E.

Twenty-five years have elapsed since the publication of Benjamin S. Bloom's article titled "Learning for Mastery." With approximately 2,000 master learning/testing citations in the ERIC data base alone, Bloom's 1968 piece is indeed one of the most generative works to appear in the educational psychology literature in decades. At this…

Making Culture Bloom

Directory of Open Access Journals (Sweden)

Iain McCalman

2013-08-01

Full Text Available On 16 June 1904, exactly one hundred years before the establishment of CHASS, an Irish Jew of Hungarian extraction called Leopold Bloom set off on a twenty-four hour perambulation around the streets and bars of Dublin. This fictional incident is the basis of James Joyce’s Ulysses, the greatest novel of modern times. It has also given rise to Bloomsday, a kind of Irish literary holy day celebrated in cities all around the world. It was a specially appropriate moment for us to celebrate the birth of our new peak body, because Bloomsday provides a perfect parable for why the Australian public and government should cherish our sector.

The Role of Bloom Index of Gelatin on the Interaction with Retinal Pigment Epithelial Cells

Directory of Open Access Journals (Sweden)

Jui Yang Lai

2009-08-01

Full Text Available Biocompatible materials are of considerable interest in the development of cell/drug delivery carriers for therapeutic applications. This paper investigates the effects of the Bloom index of gelatin on its interaction with retinal pigment epithelial (RPE cells. Following two days of culture of ARPE-19 cells with gelatin samples G75-100, G175, and G300, the in vitro biocompatibility was determined by cell proliferation and viability assays, and glutamate uptake measurements, as well as cytokine expression analyses. The mitochondrial dehydrogenase activity in the G300 groups was significantly lower than that of G75-100 and G175 groups. The Live/Dead assays also showed that the gelatin samples G300 induced mild cytotoxicity. In comparison with the treatment of gelatins with low Bloom index, the exposure to high Bloom strength gelatins markedly reduced the glutamate uptake capacity of ARPE-19 cells. One possible explanation for these observations is that the presence of gelatin samples G300 with high viscosity in the medium may affect the nutrient availability to cultured cells. The analyses of pro-inflammatory cytokine IL-6 expression at both mRNA and protein levels showed that the gelatins with low Bloom index caused less cellular inflammatory reaction and had more acceptable biocompatibility than their high Bloom strength counterparts. These findings suggest that the Bloom index gives influence on cellular responses to gelatin materials.

High frequency marine biogeochemical monitoring from a Japan-Korea ferry -1991 results

International Nuclear Information System (INIS)

Harashima, A.

1993-01-01

A ferry mounted monitoring system was developed and deployed to investigate the temporal and spatial variations of biogeochemical parameters (dissolved nutrients, phytoplankton biomass, temperature, salinity and pH) along the ship's regular route between Pusan, Korea and Kobe, Japan. Semi-continuous data recording (every 10 seconds, 4 transect cruises per week) and automated bottle sampling with filtration (24 cruises per year) were performed using the sea water taken continuously from the engine cooling system intake at 6m depth. These data are expected to clarify the natural variability in and anthropogenic changes to the coastal and marginal seas and the mechanism of algal blooming and to supply the ground truth data for the calibration-validation of algorithms to calculate pigment concentrations from ocean color remote sensing data. Since the start of monitoring (June, 1991), the data have revealed the contrast between the Seto Inland Sea and the outer continental shelf area and the spatial heterogeneities over smaller scales. Among the events apparent in this time series data are the termination of the spring bloom, the mid-summer decrease of phytoplankton biomass due to depletion of nutrients, and autumn blooms, which are characteristic of the periods following storms

A winter dinoflagellate bloom drives high rates of primary production in a Patagonian fjord ecosystem

Science.gov (United States)

Montero, P.; Pérez-Santos, I.; Daneri, G.; Gutiérrez, M. H.; Igor, G.; Seguel, R.; Purdie, D.; Crawford, D. W.

2017-12-01

A dense winter bloom of the dinoflagellate Heterocapsa triquetra was observed at a fixed station (44°35.3‧S; 72°43.6‧W) in the Puyuhuapi Fjord in Chilean Patagonia during July 2015. H. triquetra dominated the phytoplankton community in the surface waters between 2 and 15 m (13-58 × 109 cell m-2), with abundances some 3 to 15 times higher than the total abundance of the diatom assemblage, which was dominated by Skeletonema spp. The high abundance of dinoflagellates was reflected in high rates of gross primary production (GPP; 0.6-1.6 g C m-2 d-1) and chlorophyll-a concentration (Chl-a; 70-199.2 mg m-2) that are comparable to levels reported in spring diatom blooms in similar Patagonian fjords. We identify the main forcing factors behind a pulse of organic matter production during the non-productive winter season, and test the hypothesis that low irradiance levels are a key factor limiting phytoplankton blooms and subsequent productivity during winter. Principal Component Analysis (PCA) indicated that GPP rates were significantly correlated (r = -0.8, p bloom. The bloom occurred under low surface irradiance levels characteristic of austral winter and was accompanied by strong northern winds, associated with the passage of a low-pressure system, and a water column dominated by double diffusive layering. To our knowledge, this is the first report of a dense dinoflagellate bloom during deep austral winter in a Patagonian fjord, and our data challenge the paradigm of light limitation as a factor controlling phytoplankton blooms in this region in winter.

Tritiated-water detection with a 2D(γ,n)1H monitor

International Nuclear Information System (INIS)

Winn, W.G.; Baumann, N.P.

Tritiated process water is monitored by detecting the D 2 O component via the 2 D(γ,n) 1 H reaction. A probe containing a 1 to 7 mCi 24 Na (15 h) γ-source and six 3 He neutron detectors produces and monitors the 2 D(γ,n) 1 H reaction. A variety of probe configurations were examined for D 2 O detection sensitivity. The corresponding detection limits range from 6 to 280 μL for D 2 O droplets and 1 to 13 μL/cm for D 2 O streams, when 10-minute neutron counting with a 1 mCi γ-source is used. Results from two field applications illustrate the utility of the monitor

Modelling the production of dimethylsulfide during a phytoplankton bloom

Science.gov (United States)

Gabric, Albert; Murray, Nicholas; Stone, Lewi; Kohl, Manfred

1993-12-01

Dimethylsulfide (DMS) is an important sulfur-containing atmospheric trace gas of marine biogenic origin. DMS emitted from the oceans may be a precursor of tropospheric aerosols and cloud condensation nuclei (CCN), thereby affecting the Earth's radiative balance and possibly constituting a negative feedback to global warming, although this hypothesis is still somewhat controversial. The revised conceptual model of the marine pelagic food web gives a central role to planktonic bacteria. Recent experiments have shown that consumption of dissolved DMS by microbial metabolism may be more important than atmospheric exchange in controlling its concentration in surface waters and hence its ventilation to the atmosphere. In this paper we investigate the effect of the marine food web on cycling of dissolved DMS in surface waters during a phytoplankton bloom episode. A nitrogen-based flow network simulation model has been used to analyze the relative importance of the various biological and chemical processes involved. The model predictions suggest that the concentration of DMS in marine surface waters is indeed governed by bacterial metabolism. Environmental factors that affect the bacterial compartment are thus likely to have a relatively large influence on dissolved DMS concentrations. The ecological succession is particularly sensitive to the ratio of phytoplankton to bacterial nutrient uptake rates as well the interaction between herbivore food chain and the microbial loop. Importantly for the design of field studies, the model predicts that peak DMS concentrations are achieved during the decline of the phytoplankton bloom with a typical time lag between peak DMS and peak phytoplankton biomass of 1 to 2 days. Significantly, the model predicts a relatively high DMS concentration persisting after the phytoplankton bloom due to excretion from large protozoa and zooplankton, which may be an additional explanation for the lack of correlation between DMS and chlorophyll a

Calibrating the Difficulty of an Assessment Tool: The Blooming of a Statistics Examination

Science.gov (United States)

Dunham, Bruce; Yapa, Gaitri; Yu, Eugenia

2015-01-01

Bloom's taxonomy is proposed as a tool by which to assess the level of complexity of assessment tasks in statistics. Guidelines are provided for how to locate tasks at each level of the taxonomy, along with descriptions and examples of suggested test questions. Through the "Blooming" of an examination--that is, locating its constituent…

Spring Blooms Observed with Biochemical Profiling Floats from a Chemical and Biological Perspective

Science.gov (United States)

Plant, J. N.; Johnson, K. S.; Sakamoto, C.; Jannasch, H. W.; Coletti, L. J.; Elrod, V.

2015-12-01

Recently there has been renewed interest in the mechanisms which control the seasonal increases in plankton biomass (spring blooms). Changes in physical and chemical forcing (light, wind, heat and nutrients) may increase the specific growth rate of phytoplankton. These changes may also shift the predator - prey relationships within the food web structure, which can alter the balance between plankton growth and loss rates. Biogeochemical profiling floats provide a means to observe the seasonal evolution of spring blooms from a physical, chemical and biological perspective in near real time. Floats equipped with optical sensors to measure nitrate, oxygen, chlorophyll fluorescence, and optical backscatter now have a presence in many ocean regions including the North Pacific, Subarctic Pacific, North Atlantic, South Atlantic and the Southern Ocean. Data from these regions are used to compare and contrast the evolution of spring blooms. The evolution of the bloom is examined using both chemical (oxygen, nitrate) and biooptical (phytoplankton from chlorophyll fluorescence and particulate organic carbon from optical backscatter) sensors under vastly different environmental conditions.

Critical review of actually available chemical compounds for prevention and management of cyanobacterial blooms

Czech Academy of Sciences Publication Activity Database

Jančula, Daniel; Maršálek, Blahoslav

2011-01-01

Roč. 85, č. 9 (2011), s. 1415-1422 ISSN 0045-6535 R&D Projects: GA MŠk 1M0571 Institutional research plan: CEZ:AV0Z60050516 Keywords : algicide * bloom management * cyanobacterial blooms Subject RIV: EF - Botanics Impact factor: 3.206, year: 2011

Cyanobacteria, Toxins and Indicators: Full-Scale Monitoring & Bench-Scale Treatment Studies

Science.gov (United States)

Summary of: 1) Lake Erie 2014 bloom season full-scale treatment plant monitoring data for cyanobacteria and cyanobacteria toxins; 2) Follow-up work to examine the impact of pre-oxidation on suspensions of intact toxin-producing cyanobacterial cells.

Unmanned Aerial Vehicles for Alien Plant Species Detection and Monitoring

Science.gov (United States)

Dvořák, P.; Müllerová, J.; Bartaloš, T.; Brůna, J.

2015-08-01

Invasive species spread rapidly and their eradication is difficult. New methods enabling fast and efficient monitoring are urgently needed for their successful control. Remote sensing can improve early detection of invading plants and make their management more efficient and less expensive. In an ongoing project in the Czech Republic, we aim at developing innovative methods of mapping invasive plant species (semi-automatic detection algorithms) by using purposely designed unmanned aircraft (UAV). We examine possibilities for detection of two tree and two herb invasive species. Our aim is to establish fast, repeatable and efficient computer-assisted method of timely monitoring, reducing the costs of extensive field campaigns. For finding the best detection algorithm we test various classification approaches (object-, pixel-based and hybrid). Thanks to its flexibility and low cost, UAV enables assessing the effect of phenological stage and spatial resolution, and is most suitable for monitoring the efficiency of eradication efforts. However, several challenges exist in UAV application, such as geometrical and radiometric distortions, high amount of data to be processed and legal constrains for the UAV flight missions over urban areas (often highly invaded). The newly proposed UAV approach shall serve invasive species researchers, management practitioners and policy makers.

Parameter constraints of grazing response functions. Implications for phytoplankton bloom initiation

Directory of Open Access Journals (Sweden)

Jordi Solé

2016-09-01

Full Text Available Phytoplankton blooms are events of production and accumulation of phytoplankton biomass that influence ecosystem dynamics and may also have effects on socio-economic activities. Among the biological factors that affect bloom dynamics, prey selection by zooplankton may play an important role. Here we consider the initial state of development of an algal bloom and analyse how a reduced grazing pressure can allow an algal species with a lower intrinsic growth rate than a competitor to become dominant. We use a simple model with two microalgal species and one zooplankton grazer to derive general relationships between phytoplankton growth and zooplankton grazing. These relationships are applied to two common grazing response functions in order to deduce the mathematical constraints that the parameters of these functions must obey to allow the dominance of the lower growth rate competitor. To assess the usefulness of the deduced relationships in a more general framework, the results are applied in the context of a multispecies ecosystem model (ERSEM.

Protein biomarker discovery and fast monitoring for the identification and detection of Anisakids by parallel reaction monitoring (PRM) mass spectrometry.

Science.gov (United States)

Carrera, Mónica; Gallardo, José M; Pascual, Santiago; González, Ángel F; Medina, Isabel

2016-06-16

Anisakids are fish-borne parasites that are responsible for a large number of human infections and allergic reactions around the world. World health organizations and food safety authorities aim to control and prevent this emerging health problem. In the present work, a new method for the fast monitoring of these parasites is described. The strategy is divided in three steps: (i) purification of thermostable proteins from fish-borne parasites (Anisakids), (ii) in-solution HIFU trypsin digestion and (iii) monitoring of several peptide markers by parallel reaction monitoring (PRM) mass spectrometry. This methodology allows the fast detection of Anisakids in Biomarker Discovery and the Fast Monitoring for the identification and detection of Anisakids in fishery products. The strategy is based on the purification of thermostable proteins, the use of accelerated in-solution trypsin digestions under an ultrasonic field provided by High-Intensity Focused Ultrasound (HIFU) and the monitoring of several peptide biomarkers by Parallel Reaction Monitoring (PRM) Mass Spectrometry in a linear ion trap mass spectrometer. The workflow allows the unequivocal detection of Anisakids, in <2h. The present strategy constitutes the fastest method for Anisakids detection, whose application in the food quality control area, could provide to the authorities an effective and rapid method to guarantee the safety to the consumers. Copyright © 2016 Elsevier B.V. All rights reserved.

Novel Damage Detection Techniques for Structural Health Monitoring Using a Hybrid Sensor

Directory of Open Access Journals (Sweden)

Dengjiang Wang

2016-01-01

Full Text Available This study presents a technique for detecting fatigue cracks based on a hybrid sensor monitoring system consisting of a combination of intelligent coating monitoring (ICM and piezoelectric transducer (PZT sensors. An experimental procedure using this hybrid sensor system was designed to monitor the cracks generated by fatigue testing in plate structures. A probability of detection (POD model that quantifies the reliability of damage detection for a specific sensor or the nondestructive testing (NDT method was used to evaluate the weight factor for the ICM and PZT sensors. To estimate the uncertainty of model parameters in this study, the Bayesian method was employed. Realistic data from fatigue testing was used to validate the overall method, and the results show that the novel damage detection technique using a hybrid sensor can quantify fatigue cracks more accurately than results obtained by conventional sensor methods.

Pronounced daily succession of phytoplankton, archaea and bacteria following a spring bloom.

Science.gov (United States)

Needham, David M; Fuhrman, Jed A

2016-02-29

Marine phytoplankton perform approximately half of global carbon fixation, with their blooms contributing disproportionately to carbon sequestration(1), and most phytoplankton production is ultimately consumed by heterotrophic prokaryotes(2). Therefore, phytoplankton and heterotrophic community dynamics are important in modelling carbon cycling and the impacts of global change(3). In a typical bloom, diatoms dominate initially, transitioning over several weeks to smaller and motile phytoplankton(4). Here, we show unexpected, rapid community variation from daily rRNA analysis of phytoplankton and prokaryotic community members following a bloom off southern California. Analysis of phytoplankton chloroplast 16S rRNA demonstrated ten different dominant phytoplankton over 18 days alone, including four taxa with animal toxin-producing strains. The dominant diatoms, flagellates and picophytoplankton varied dramatically in carbon export potential. Dominant prokaryotes also varied rapidly. Euryarchaea briefly became the most abundant organism, peaking over a few days to account for about 40% of prokaryotes. Phytoplankton and prokaryotic communities correlated better with each other than with environmental parameters. Extending beyond the traditional view of blooms being controlled primarily by physics and inorganic nutrients, these dynamics imply highly heterogeneous, continually changing conditions over time and/or space and suggest that interactions among microorganisms are critical in controlling plankton diversity, dynamics and fates.

The Adaptive-Clustering and Error-Correction Method for Forecasting Cyanobacteria Blooms in Lakes and Reservoirs

Directory of Open Access Journals (Sweden)

Xiao-zhe Bai

2017-01-01

Full Text Available Globally, cyanobacteria blooms frequently occur, and effective prediction of cyanobacteria blooms in lakes and reservoirs could constitute an essential proactive strategy for water-resource protection. However, cyanobacteria blooms are very complicated because of the internal stochastic nature of the system evolution and the external uncertainty of the observation data. In this study, an adaptive-clustering algorithm is introduced to obtain some typical operating intervals. In addition, the number of nearest neighbors used for modeling was optimized by particle swarm optimization. Finally, a fuzzy linear regression method based on error-correction was used to revise the model dynamically near the operating point. We found that the combined method can characterize the evolutionary track of cyanobacteria blooms in lakes and reservoirs. The model constructed in this paper is compared to other cyanobacteria-bloom forecasting methods (e.g., phase space reconstruction and traditional-clustering linear regression, and, then, the average relative error and average absolute error are used to compare the accuracies of these models. The results suggest that the proposed model is superior. As such, the newly developed approach achieves more precise predictions, which can be used to prevent the further deterioration of the water environment.

A measurement-based fault detection approach applied to monitor robots swarm

KAUST Repository

Khaldi, Belkacem

2017-07-10

Swarm robotics requires continuous monitoring to detect abnormal events and to sustain normal operations. Indeed, swarm robotics with one or more faulty robots leads to degradation of performances complying with the target requirements. This paper present an innovative data-driven fault detection method for monitoring robots swarm. The method combines the flexibility of principal component analysis (PCA) models and the greater sensitivity of the exponentially-weighted moving average control chart to incipient changes. We illustrate through simulated data collected from the ARGoS simulator that a significant improvement in fault detection can be obtained by using the proposed methods as compared to the use of the conventional PCA-based methods.

Energy Efficient Monitoring for Intrusion Detection in Battery-Powered Wireless Mesh Networks

KAUST Repository

Hassanzadeh, Amin

2011-07-18

Wireless Mesh Networks (WMN) are easy-to-deploy, low cost solutions for providing networking and internet services in environments with no network infrastructure, e.g., disaster areas and battlefields. Since electric power is not readily available in such environments battery-powered mesh routers, operating in an energy efficient manner, are required. To the best of our knowledge, the impact of energy efficient solutions, e.g., involving duty-cycling, on WMN intrusion detection systems, which require continuous monitoring, remains an open research problem. In this paper we propose that carefully chosen monitoring mesh nodes ensure continuous and complete detection coverage, while allowing non-monitoring mesh nodes to save energy through duty-cycling. We formulate the monitoring node selection problem as an optimization problem and propose distributed and centralized solutions for it, with different tradeoffs. Through extensive simulations and a proof-of-concept hardware/software implementation we demonstrate that our solutions extend the WMN lifetime by 8%, while ensuring, at the minimum, a 97% intrusion detection rate.

Spatial Outlier Detection of CO2 Monitoring Data Based on Spatial Local Outlier Factor

Directory of Open Access Journals (Sweden)

Liu Xin

2015-12-01

Full Text Available Spatial local outlier factor (SLOF algorithm was adopted in this study for spatial outlier detection because of the limitations of the traditional static threshold detection. Based on the spatial characteristics of CO2 monitoring data obtained in the carbon capture and storage (CCS project, the K-Nearest Neighbour (KNN graph was constructed using the latitude and longitude information of the monitoring points to identify the spatial neighbourhood of the monitoring points. Then SLOF was adopted to calculate the outlier degrees of the monitoring points and the 3σ rule was employed to identify the spatial outlier. Finally, the selection of K value was analysed and the optimal one was selected. The results show that, compared with the static threshold method, the proposed algorithm has a higher detection precision. It can overcome the shortcomings of the static threshold method and improve the accuracy and diversity of local outlier detection, which provides a reliable reference for the safety assessment and warning of CCS monitoring.

Deep-sea bioluminescence blooms after dense water formation at the ocean surface.

Directory of Open Access Journals (Sweden)

Christian Tamburini

Full Text Available The deep ocean is the largest and least known ecosystem on Earth. It hosts numerous pelagic organisms, most of which are able to emit light. Here we present a unique data set consisting of a 2.5-year long record of light emission by deep-sea pelagic organisms, measured from December 2007 to June 2010 at the ANTARES underwater neutrino telescope in the deep NW Mediterranean Sea, jointly with synchronous hydrological records. This is the longest continuous time-series of deep-sea bioluminescence ever recorded. Our record reveals several weeks long, seasonal bioluminescence blooms with light intensity up to two orders of magnitude higher than background values, which correlate to changes in the properties of deep waters. Such changes are triggered by the winter cooling and evaporation experienced by the upper ocean layer in the Gulf of Lion that leads to the formation and subsequent sinking of dense water through a process known as "open-sea convection". It episodically renews the deep water of the study area and conveys fresh organic matter that fuels the deep ecosystems. Luminous bacteria most likely are the main contributors to the observed deep-sea bioluminescence blooms. Our observations demonstrate a consistent and rapid connection between deep open-sea convection and bathypelagic biological activity, as expressed by bioluminescence. In a setting where dense water formation events are likely to decline under global warming scenarios enhancing ocean stratification, in situ observatories become essential as environmental sentinels for the monitoring and understanding of deep-sea ecosystem shifts.

Deep-sea bioluminescence blooms after dense water formation at the ocean surface.

Science.gov (United States)

Tamburini, Christian; Canals, Miquel; Durrieu de Madron, Xavier; Houpert, Loïc; Lefèvre, Dominique; Martini, Séverine; D'Ortenzio, Fabrizio; Robert, Anne; Testor, Pierre; Aguilar, Juan Antonio; Samarai, Imen Al; Albert, Arnaud; André, Michel; Anghinolfi, Marco; Anton, Gisela; Anvar, Shebli; Ardid, Miguel; Jesus, Ana Carolina Assis; Astraatmadja, Tri L; Aubert, Jean-Jacques; Baret, Bruny; Basa, Stéphane; Bertin, Vincent; Biagi, Simone; Bigi, Armando; Bigongiari, Ciro; Bogazzi, Claudio; Bou-Cabo, Manuel; Bouhou, Boutayeb; Bouwhuis, Mieke C; Brunner, Jurgen; Busto, José; Camarena, Francisco; Capone, Antonio; Cârloganu, Christina; Carminati, Giada; Carr, John; Cecchini, Stefano; Charif, Ziad; Charvis, Philippe; Chiarusi, Tommaso; Circella, Marco; Coniglione, Rosa; Costantini, Heide; Coyle, Paschal; Curtil, Christian; Decowski, Patrick; Dekeyser, Ivan; Deschamps, Anne; Donzaud, Corinne; Dornic, Damien; Dorosti, Hasankiadeh Q; Drouhin, Doriane; Eberl, Thomas; Emanuele, Umberto; Ernenwein, Jean-Pierre; Escoffier, Stéphanie; Fermani, Paolo; Ferri, Marcelino; Flaminio, Vincenzo; Folger, Florian; Fritsch, Ulf; Fuda, Jean-Luc; Galatà, Salvatore; Gay, Pascal; Giacomelli, Giorgio; Giordano, Valentina; Gómez-González, Juan-Pablo; Graf, Kay; Guillard, Goulven; Halladjian, Garadeb; Hallewell, Gregory; van Haren, Hans; Hartman, Joris; Heijboer, Aart J; Hello, Yann; Hernández-Rey, Juan Jose; Herold, Bjoern; Hößl, Jurgen; Hsu, Ching-Cheng; de Jong, Marteen; Kadler, Matthias; Kalekin, Oleg; Kappes, Alexander; Katz, Uli; Kavatsyuk, Oksana; Kooijman, Paul; Kopper, Claudio; Kouchner, Antoine; Kreykenbohm, Ingo; Kulikovskiy, Vladimir; Lahmann, Robert; Lamare, Patrick; Larosa, Giuseppina; Lattuada, Dario; Lim, Gordon; Presti, Domenico Lo; Loehner, Herbert; Loucatos, Sotiris; Mangano, Salvatore; Marcelin, Michel; Margiotta, Annarita; Martinez-Mora, Juan Antonio; Meli, Athina; Montaruli, Teresa; Moscoso, Luciano; Motz, Holger; Neff, Max; Nezri, Emma Nuel; Palioselitis, Dimitris; Păvălaş, Gabriela E; Payet, Kevin; Payre, Patrice; Petrovic, Jelena; Piattelli, Paolo; Picot-Clemente, Nicolas; Popa, Vlad; Pradier, Thierry; Presani, Eleonora; Racca, Chantal; Reed, Corey; Riccobene, Giorgio; Richardt, Carsten; Richter, Roland; Rivière, Colas; Roensch, Kathrin; Rostovtsev, Andrei; Ruiz-Rivas, Joaquin; Rujoiu, Marius; Russo, Valerio G; Salesa, Francisco; Sánchez-Losa, Augustin; Sapienza, Piera; Schöck, Friederike; Schuller, Jean-Pierre; Schussler, Fabian; Shanidze, Rezo; Simeone, Francesco; Spies, Andreas; Spurio, Maurizio; Steijger, Jos J M; Stolarczyk, Thierry; Taiuti, Mauro G F; Toscano, Simona; Vallage, Bertrand; Van Elewyck, Véronique; Vannoni, Giulia; Vecchi, Manuela; Vernin, Pascal; Wijnker, Guus; Wilms, Jorn; de Wolf, Els; Yepes, Harold; Zaborov, Dmitry; De Dios Zornoza, Juan; Zúñiga, Juan

2013-01-01

The deep ocean is the largest and least known ecosystem on Earth. It hosts numerous pelagic organisms, most of which are able to emit light. Here we present a unique data set consisting of a 2.5-year long record of light emission by deep-sea pelagic organisms, measured from December 2007 to June 2010 at the ANTARES underwater neutrino telescope in the deep NW Mediterranean Sea, jointly with synchronous hydrological records. This is the longest continuous time-series of deep-sea bioluminescence ever recorded. Our record reveals several weeks long, seasonal bioluminescence blooms with light intensity up to two orders of magnitude higher than background values, which correlate to changes in the properties of deep waters. Such changes are triggered by the winter cooling and evaporation experienced by the upper ocean layer in the Gulf of Lion that leads to the formation and subsequent sinking of dense water through a process known as "open-sea convection". It episodically renews the deep water of the study area and conveys fresh organic matter that fuels the deep ecosystems. Luminous bacteria most likely are the main contributors to the observed deep-sea bioluminescence blooms. Our observations demonstrate a consistent and rapid connection between deep open-sea convection and bathypelagic biological activity, as expressed by bioluminescence. In a setting where dense water formation events are likely to decline under global warming scenarios enhancing ocean stratification, in situ observatories become essential as environmental sentinels for the monitoring and understanding of deep-sea ecosystem shifts.

Phytoplankton ice-edge blooms in the marginal ice zone at Princess Astrid Coast in Antarctica

Digital Repository Service at National Institute of Oceanography (India)

Verlecar, X.N.; Dhargalkar, V.K.; Goswami, S.C.; Mhamal, N.P.

dominated the bloom conditions and nannoplankton (5 to 20 mu m) prevail the non-bloom periods while the picoplankton (less than 5 mu m) constituted a minor fraction during most of the period. Weekly changes in phytoplankton showed inverse relationship...

Sensitivity Verification of PWR Monitoring System Using Neuro-Expert For LOCA Detection

International Nuclear Information System (INIS)

Muhammad Subekti

2009-01-01

Sensitivity Verification of PWR Monitoring System Using Neuro-Expert For LOCA Detection. The present research was done for verification of previous developed method on Loss of Coolant Accident (LOCA) detection and perform simulations for knowing the sensitivity of the PWR monitoring system that applied neuro-expert method. The previous research continuing on present research, has developed and has tested the neuro-expert method for several anomaly detections in Nuclear Power Plant (NPP) typed Pressurized Water Reactor (PWR). Neuro-expert can detect the LOCA anomaly with sensitivity of primary coolant leakage of 7 gallon/min and the conventional method could not detect the primary coolant leakage of 30 gallon/min. Neuro expert method detects significantly LOCA anomaly faster than conventional system in Surry-1 NPP as well so that the impact risk is reducible. (author)

Adaptive Change Detection for Long-Term Machinery Monitoring Using Incremental Sliding-Window

Science.gov (United States)

Wang, Teng; Lu, Guo-Liang; Liu, Jie; Yan, Peng

2017-11-01

Detection of structural changes from an operational process is a major goal in machine condition monitoring. Existing methods for this purpose are mainly based on retrospective analysis, resulting in a large detection delay that limits their usages in real applications. This paper presents a new adaptive real-time change detection algorithm, an extension of the recent research by combining with an incremental sliding-window strategy, to handle the multi-change detection in long-term monitoring of machine operations. In particular, in the framework, Hilbert space embedding of distribution is used to map the original data into the Re-producing Kernel Hilbert Space (RKHS) for change detection; then, a new adaptive threshold strategy can be developed when making change decision, in which a global factor (used to control the coarse-to-fine level of detection) is introduced to replace the fixed value of threshold. Through experiments on a range of real testing data which was collected from an experimental rotating machinery system, the excellent detection performances of the algorithm for engineering applications were demonstrated. Compared with state-of-the-art methods, the proposed algorithm can be more suitable for long-term machinery condition monitoring without any manual re-calibration, thus is promising in modern industries.

Heterosigma bloom and associated fish kill

Science.gov (United States)

Hershberger, P.K.; Rensel, J.E.; Postel, J.R.; Taub, F.B.

1997-01-01

A bloom of the harmful marine phytoplankton, Heterosigma carterae occurred in upper Case Inlet, south Puget Sound, Washington in late September, 1994, correlating with the presence of at least 35 dead salmon. This marks the first time that this alga has been closely correlated with a wild fish kill; in the past it was thought to be associated with kills of penned fish at fish farms only. We were informed of the presence of a possible harmful algal bloom and dead salinois Ilear the town of Allyn on 27 September and a team was formed to investigate. We arrived at the Allyn waterfront at 17:30 hours the same day. Prior to our arrival, state agency personnel walked approximatcly two miles of shoreline from the powerlines north of the dock, to the mouth of Sherwood Creek and conducted the only official count of dead fish present along the shore consisting of 12 coho salmon (Oncorhynchus kisutch), 11 chum salmon (Oncorhynchus keta), 12 chinook salmon (Oncorhynchus tschawytscha), one flat fish, and one sculpin on the morning of 9/27. Since previous harmful blooms of Heterosigma have resultedin the majority of net penreared salmon sinking to the bottom of pens, and only approximately two miles of shoreline were sampled, it is suspected that many more exposed fish may have succumbed than were counted. Witnesses who explored the east side of the bay reported seeing many dead salmon there as well, but no counts were made. State agency personnel who observed the fish kill reported seeing “dying fish coming to the beach, gulping at the surface, trying to get out of the water” Scavengers were seen consuming the salmon carcasses; these included two harbor seals, a house cat, and Hymenopteran insects. None suffered any noticeable acute ill effects. Although precise cause of death has not been ascertained, visual inspection of the reproductive organs from a deceased male chum salmon found on the shore at Allyn confirmed that the fish was not yet reproductively mature and

Image edge detection based tool condition monitoring with morphological component analysis.

Science.gov (United States)

Yu, Xiaolong; Lin, Xin; Dai, Yiquan; Zhu, Kunpeng

2017-07-01

The measurement and monitoring of tool condition are keys to the product precision in the automated manufacturing. To meet the need, this study proposes a novel tool wear monitoring approach based on the monitored image edge detection. Image edge detection has been a fundamental tool to obtain features of images. This approach extracts the tool edge with morphological component analysis. Through the decomposition of original tool wear image, the approach reduces the influence of texture and noise for edge measurement. Based on the target image sparse representation and edge detection, the approach could accurately extract the tool wear edge with continuous and complete contour, and is convenient in charactering tool conditions. Compared to the celebrated algorithms developed in the literature, this approach improves the integrity and connectivity of edges, and the results have shown that it achieves better geometry accuracy and lower error rate in the estimation of tool conditions. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

Dog Poisonings Associated with a Microcystis aeruginosa Bloom in the Netherlands

Directory of Open Access Journals (Sweden)

Miquel Lürling

2013-03-01

Full Text Available In early autumn 2011, three dogs died after they had been exposed to a Microcystis aeruginosa bloom on Lake Amstelmeer, The Netherlands. The cyanobacterial scum from the lake contained up to 5.27 × 103 μg g−1 dry-weight microcystin, the vomit of one of the dogs contained on average 94 µg microcystin g−1 dry-weight. In both cases, microcystin-LR was the most abundant variant. This is the first report of dog deaths associated with a Microcystis bloom and microcystin poisoning in The Netherlands.

Retreived bacteria from Noctiluca miliaris (green) bloom of the northeastern Arabian Sea

Science.gov (United States)

Basu, Subhajit; Matondkar, S. G. Prabhu; Furtado, Irene

2013-01-01

In recent years, seasonal blooms of the dinoflagellate Noctiluca miliaris have appeared in the open-waters of the northern Arabian Sea (NAS). This study provides the first characterization of bacteria from a seasonal bloom of green Noctiluca of NAS (20°N-17°N and 64°E-70°E), during the spring-inter-monsoon cruise of Sagar Sampada 253, in March 2007. Bacterial growth as assessed by most-probable number (MPN) and plate counts, revealed `variable-physiotypes' over a wide range of salinities (0%-25% w/v NaCl), pH levels (5-8.5), and organic nutrient strengths, in comparison to non-bloom waters. MPN indices of bacteria in surface waters of bloom stations *DWK and *PRB, corresponded to (3.08-4.41)×103 cells/mL at 3.5% NaCl (w/v), and (2.82-9.49)×102 cells/mL at 25% (w/v) NaCl in tryptone-yeast extract broth (TYE). Plate counts were (1.12-4)×106 CFU/mL at 0% (w/v) NaCl, (1.28-3.9)×106 CFU/mL at 3.5% (w/v) NaCl, and (0.4-7)×104 CFU/mL at 25% NaCl (w/v) on TYE. One-tenth-strength Zobell's gave (0.6-3.74)×105 CFU/mL at pH 5 to (3.58-7.5)×105 CFU/mL at pH 8.5. These bacteria were identified to the genera Bacillus, Cellulomonas, Staphylococcus, Planococcus, Dietzia, Virgibacillus, Micrococcus, Sporosarcinae, Leucobacter, and Halomonas. The identity of three strains (GUFBSS253N2, GUFBSS253N30, and GUFBSS253N84) was confirmed through 16S rDNA sequence homology as Bacillus cohnii, Bacillus flexus, and Bacillus cereus. The ˜2-3-fold higher plate counts of culturable bacteria from the open-waters of the NAS indicate that these bacteria could critically determine the biogeochemical dynamics of the bloom and its milieu. The role of these bacteria in sustaining/terminating the bloom is under evaluation.

Differential response of coral communities to Caulerpa spp. bloom in the reefs of Indian Ocean

Digital Repository Service at National Institute of Oceanography (India)

Manikandan, B.; Ravindran, J.

of this study suggested that the recovery of a coral reef after a macroalgal bloom largely depends on coral species composition and the frequency of stress events. A further study linking macroalgal bloom to its specific cause is essential for the successful...

Portal monitoring for detecting fissile materials and chemical explosives

International Nuclear Information System (INIS)

Albright, D.

1992-01-01

The portal monitoring of pedestrians, packages, equipment, and vehicles entering or leaving areas of high physical security has been common for many years. Many nuclear facilities rely on portal monitoring to prevent the theft or diversion of plutonium and highly enriched uranium. At commercial airports, portals are used to prevent firearms and explosives from being smuggled onto airplanes. An August 1989 Federal Aviation Administration (FAA) regulation requires US airlines to screen luggage on international flights for chemical explosives. This paper reports that portal monitoring is now being introduced into arms-control agreements. Because some of the portal-monitoring equipment that would be useful in verifying arms-control agreements is already widely used as part of the physical security systems at nuclear facilities and commercial airports, the authors review these uses of portal monitoring, as well as its role in verifying the INF treaty. Then the authors survey the major types of portal-monitoring equipment that would be most useful in detecting nuclear warheads or fissile material

Investigation of the 2006 Alexandrium fundyense Bloom in the Gulf of Maine: In situ Observations and Numerical Modeling.

Science.gov (United States)

Li, Yizhen; He, Ruoying; McGillicuddy, Dennis J; Anderson, Donald M; Keafer, Bruce A

2009-09-30

In situ observations and a coupled bio-physical model were used to study the germination, initiation, and development of the Gulf of Maine (GOM) Alexandrium fundyense bloom in 2006. Hydrographic measurements and comparisons with GOM climatology indicate that 2006 was a year with normal coastal water temperature, salinity, current and river runoff conditions. A. fundyense cyst abundance in bottom sediments preceding the 2006 bloom was at a moderate level compared to other recent annual cyst survey data. We used the coupled bio-physical model to hindcast coastal circulation and A. fundyense cell concentrations. Field data including water temperature, salinity, velocity time series and surface A. fundyense cell concentration maps were applied to gauge the model's fidelity. The coupled model is capable of reproducing the hydrodynamics and the temporal and spatial distributions of A. fundyense cell concentration reasonably well. Model hindcast solutions were further used to diagnose physical and biological factors controlling the bloom dynamics. Surface wind fields modulated the bloom's horizontal and vertical distribution. The initial cyst distribution was found to be the dominant factor affecting the severity and the interannual variability of the A. fundyense bloom. Initial cyst abundance for the 2006 bloom was about 50% of that prior to the 2005 bloom. As the result, the time-averaged gulf-wide cell concentration in 2006 was also only about 60% of that in 2005. In addition, weaker alongshore currents and episodic upwelling-favorable winds in 2006 reduced the spatial extent of the bloom as compared with 2005.

Host-Specificity and Dynamics in Bacterial Communities Associated with Bloom-Forming Freshwater Phytoplankton

Science.gov (United States)

Bagatini, Inessa Lacativa; Eiler, Alexander; Bertilsson, Stefan; Klaveness, Dag; Tessarolli, Letícia Piton; Vieira, Armando Augusto Henriques

2014-01-01

Many freshwater phytoplankton species have the potential to form transient nuisance blooms that affect water quality and other aquatic biota. Heterotrophic bacteria can influence such blooms via nutrient regeneration but also via antagonism and other biotic interactions. We studied the composition of bacterial communities associated with three bloom-forming freshwater phytoplankton species, the diatom Aulacoseira granulata and the cyanobacteria Microcystis aeruginosa and Cylindrospermopsis raciborskii. Experimental cultures incubated with and without lake bacteria were sampled in three different growth phases and bacterial community composition was assessed by 454-Pyrosequencing of 16S rRNA gene amplicons. Betaproteobacteria were dominant in all cultures inoculated with lake bacteria, but decreased during the experiment. In contrast, Alphaproteobacteria, which made up the second most abundant class of bacteria, increased overall during the course of the experiment. Other bacterial classes responded in contrasting ways to the experimental incubations causing significantly different bacterial communities to develop in response to host phytoplankton species, growth phase and between attached and free-living fractions. Differences in bacterial community composition between cyanobacteria and diatom cultures were greater than between the two cyanobacteria. Despite the significance, major differences between phytoplankton cultures were in the proportion of the OTUs rather than in the absence or presence of specific taxa. Different phytoplankton species favoring different bacterial communities may have important consequences for the fate of organic matter in systems where these bloom forming species occur. The dynamics and development of transient blooms may also be affected as bacterial communities seem to influence phytoplankton species growth in contrasting ways. PMID:24465807

Detection and monitoring of invasive exotic plants: a comparison of four sampling methods

Science.gov (United States)

Cynthia D. Huebner

2007-01-01

The ability to detect and monitor exotic invasive plants is likely to vary depending on the sampling method employed. Methods with strong qualitative thoroughness for species detection often lack the intensity necessary to monitor vegetation change. Four sampling methods (systematic plot, stratified-random plot, modified Whittaker, and timed meander) in hemlock and red...

Future Climate Impacts on Harmful Algal Blooms in an Agriculturally Dominated Ecosystem

Science.gov (United States)

Aloysius, N. R.; Martin, J.; Ludsin, S.; Stumpf, R. P.

2015-12-01

Cyanobacteria blooms have become a major problem worldwide in aquatic ecosystems that receive excessive runoff of limiting nutrients from terrestrial drainage. Such blooms often are considered harmful because they degrade ecosystem services, threaten public health, and burden local economies. Owing to changing agricultural land-use practices, Lake Erie, the most biologically productive of the North American Great Lakes, has begun to undergo a re-eutrophication in which the frequency and extent of harmful algal blooms (HABs) has increased. Continued climate change has been hypothesized to magnify the HAB problem in Lake Erie in the absence of new agricultural management practices, although this hypothesis has yet to be formally tested empirically. Herein, we tested this hypothesis by predicting how the frequency and extent of potentially harmful cyanobacteria blooms will change in Lake Erie during the 21st century under the Intergovernmental Panel on Climate Change Fifth Assessment climate projections in the region. To do so, we used 80 ensembles of climate projections from 20 Global Climate Models (GCMs) and two greenhouse gas emission scenarios (moderate reduction, RCP4.5; business-as-usual, RCP8.5) to drive a spatiotemporally explicit watershed-hydrology model that was linked to several statistical predictive models of annual cyanobacteria blooms in Lake Erie. Owing to anticipated increases in precipitation during spring and warmer temperatures during summer, our ensemble of predictions revealed that, if current land-management practices continue, the frequency of severe HABs in Lake Erie will increase during the 21st century. These findings identify a real need to consider future climate projections when developing nutrient reduction strategies in the short term, with adaptation also needing to be encouraged under both greenhouse gas emissions scenarios in the absence of effective nutrient mitigation strategies.

Spatial analysis of freshwater lake cyanobacteria blooms, 2008-2011

Science.gov (United States)

Background/Question/Methods Cyanobacteria and associated harmful algal blooms cause significant social, economic, and environmental impacts. Cyanobacteria synthesize hepatotoxins, neurotoxins, and dermatotoxins, affecting the health of humans and other species. The Cyanobacteria ...

Advanced Oil Spill Detection Algorithms For Satellite Based Maritime Environment Monitoring

Science.gov (United States)

Radius, Andrea; Azevedo, Rui; Sapage, Tania; Carmo, Paulo

2013-12-01

During the last years, the increasing pollution occurrence and the alarming deterioration of the environmental health conditions of the sea, lead to the need of global monitoring capabilities, namely for marine environment management in terms of oil spill detection and indication of the suspected polluter. The sensitivity of Synthetic Aperture Radar (SAR) to the different phenomena on the sea, especially for oil spill and vessel detection, makes it a key instrument for global pollution monitoring. The SAR performances in maritime pollution monitoring are being operationally explored by a set of service providers on behalf of the European Maritime Safety Agency (EMSA), which has launched in 2007 the CleanSeaNet (CSN) project - a pan-European satellite based oil monitoring service. EDISOFT, which is from the beginning a service provider for CSN, is continuously investing in R&D activities that will ultimately lead to better algorithms and better performance on oil spill detection from SAR imagery. This strategy is being pursued through EDISOFT participation in the FP7 EC Sea-U project and in the Automatic Oil Spill Detection (AOSD) ESA project. The Sea-U project has the aim to improve the current state of oil spill detection algorithms, through the informative content maximization obtained with data fusion, the exploitation of different type of data/ sensors and the development of advanced image processing, segmentation and classification techniques. The AOSD project is closely related to the operational segment, because it is focused on the automation of the oil spill detection processing chain, integrating auxiliary data, like wind information, together with image and geometry analysis techniques. The synergy between these different objectives (R&D versus operational) allowed EDISOFT to develop oil spill detection software, that combines the operational automatic aspect, obtained through dedicated integration of the processing chain in the existing open source NEST

If You Don't Know Who Wrote it, You Won't Understand It: Lessons Learned from Benjamin S. Bloom.

Science.gov (United States)

Anderson, Lorin W.

1996-01-01

Describes how one college professor's relationship with author Benjamin Bloom influenced his thinking about education and his reading of education. Explains how the professor's personal and professional understandings of Bloom influenced his reading of virtually all of Bloom's writings, and discusses three points that are central to understanding…

Shallow water processes govern system-wide phytoplankton bloom dynamics: A modeling study

Science.gov (United States)

Lucas, L.V.; Koseff, Jeffrey R.; Monismith, Stephen G.; Thompson, J.K.

2009-01-01

A pseudo-two-dimensional numerical model of estuarine phytoplankton growth and consumption, vertical turbulent mixing, and idealized cross-estuary transport was developed and applied to South San Francisco Bay. This estuary has two bathymetrically distinct habitat types (deep channel, shallow shoal) and associated differences in local net rates of phytoplankton growth and consumption, as well as differences in the water column's tendency to stratify. Because many physical and biological time scales relevant to algal population dynamics decrease with decreasing depth, process rates can be especially fast in the shallow water. We used the model to explore the potential significance of hydrodynamic connectivity between a channel and shoal and whether lateral transport can allow physical or biological processes (e.g. stratification, benthic grazing, light attenuation) in one sub-region to control phytoplankton biomass and bloom development in the adjacent sub-region. Model results for South San Francisco Bay suggest that lateral transport from a productive shoal can result in phytoplankton biomass accumulation in an adjacent deep, unproductive channel. The model further suggests that turbidity and benthic grazing in the shoal can control the occurrence of a bloom system-wide; whereas, turbidity, benthic grazing, and vertical density stratification in the channel are likely to only control local bloom occurrence or modify system-wide bloom magnitude. Measurements from a related field program are generally consistent with model-derived conclusions. ?? 2008 Elsevier B.V.

Ulva blooms in the southwestern Gulf of California: Reproduction and biomass

Science.gov (United States)

Chávez-Sánchez, Tonatiuh; Piñón-Gimate, Alejandra; Serviere-Zaragoza, Elisa; López-Bautista, Juan Manuel; Casas-Valdez, Margarita

2018-01-01

Ulvacean blooms are generally characterized by one or more Ulva species, some of which are common to blooms across a broad geographic range. In tropical environments the identified stimuli that induce reproductive development of Ulva are restricted to temperature, salinity, dehydration and fragmentation. Culture studies have been prolific in describing the reproduction of Ulva species, but its reproductive changes in natural environment have not been described yet. Hence, seasonal changes were described in reproductive stages and their relationship with biomass and environmental factors of Ulva species at four macroalgal blooms in a subtropical bay. Eight Ulva species were found: U. acanthophora, U. clathrata, U. flexuosa, U. intestinalis, U. lactuca, U. lobata, U. nematoidea and U. rigida. Reproductive stage and biomass varied according to site and season. Five species showed four reproductive stages (vegetative, thallus with fully differentiated zooids in formation and empty cells after zooids release); for the remaining species only vegetative thalli were found. Ulva rigida showed the highest biomass values, followed by U. acanthophora, following a seasonal pattern.

Presence of microcystin during events of algal blooms in Araruama Lagoon

Directory of Open Access Journals (Sweden)

Manildo Marcião de Oliveira

2012-04-01

Full Text Available Algal blooms are phenomena produced by anthropogenic activities, despite the possible natural causes. In Araruama Lagoon, blooms occurred in 2005 and in subsequent years, causing profound changes in phytoplankton communities. These episodes triggered events of extensive fish mortality associated with low levels of dissolved oxygen. Another adverse effect associated with blooms is the production of harmful toxins such as phycotoxins produced by eukaryotic microalgae and cyanotoxins produced by cyanobacteria. Samples of fish (mullet and menhaden and seston showed levels of microcystin by enzyme-linked immunosorbent assay (ELISA, also a seston sample (São Pedro d'Aldeia on 08/22/2007, in a period not related to fish mortality, showed cells which contained genes encoding microcystin synthetase, an enzyme responsible for the synthesis of microcystin. The succession of microalgae with the concomitant presence of potentially toxic cyanobacteria draws attention to the risk of chronic exposure by the population that uses fish as their main protein source.

Long-range alpha detection applied to soil surface monitoring

International Nuclear Information System (INIS)

Caress, R.W.; Allander, K.S.; Bounds, J.A.; Catlett, M.M.; MacArthur, D.W.; Rutherford, D.A.

1992-01-01

The long-range alpha detection (LRAD) technique depends on the detection of ion pairs generated by alpha particles losing energy in air rather than on detection of the alpha particles themselves. Typical alpha particles generated by uranium will travel less than 3 cm in air. In contrast, the ions have been successfully detected many inches or feet away from the contamination. Since LRAD detection systems are sensitive to all ions simultaneously, large LRAD soil surface monitors (SSMS) can be used to collect all of the ions from a large sample. The LRAD SSMs are designed around the fan-less LRAD detector. In this case a five-sided box with an open bottom is placed on the soil surface. Ions generated by alpha decays on the soil surface are collected on a charged copper plate within the box. These ions create a small current from the plate to ground which is monitored with a sensitive electrometer. The current measured is proportional to the number of ions in the box, which is, in turn, proportional to the amount of alpha contamination on the surface of the soil. This report includes the design and construction of a 1-m by 1-m SSM as well as the results of a study at Fernald, OH, as part of the Uranium in Soils Integrated Demonstration

Evaluation of a hygiene monitor for detection of contamination in dental surgeries.

Science.gov (United States)

Douglas, C W; Rothwell, P S

1991-05-11

Routines for disinfecting working surfaces in dental surgeries are difficult to monitor without time-consuming and labour-intensive microbiological techniques, yet effective monitoring is a vital part of cross-infection control. Easy to use, on-site methods would be valuable in this context. This study evaluates a portable monitor, the Biotrace Hygiene Monitor, which uses bioluminescence to measure adenosine triphosphate (ATP) on surfaces. Under laboratory conditions, the ability of the monitor to detect whole saliva and Streptococcus sanguis was determined and, in the general practice environment, the level of ATP on surfaces in five dental surgeries was assessed. The minimum amount of saliva detectable was 0.5 microliters and in surgeries, the monitor readily identified numerous surfaces with fairly high levels of ATP. Routine cleaning methods sometimes left ATP on surfaces at levels which represented a cross-infection risk, if it is assumed that the ATP derived from patients' saliva. Modification of cleaning methods resulted in a reduction of ATP levels to within that which could be considered reasonably practicably safe. It is concluded that the Biotrace Hygiene Monitor offers a simple and valuable means of monitoring dental practice cleaning routines.

Dealing with incomplete and variable detectability in multi-year, multi-site monitoring of ecological populations

Science.gov (United States)

Converse, Sarah J.; Royle, J. Andrew; Gitzen, Robert A.; Millspaugh, Joshua J.; Cooper, Andrew B.; Licht, Daniel S.

2012-01-01

An ecological monitoring program should be viewed as a component of a larger framework designed to advance science and/or management, rather than as a stand-alone activity. Monitoring targets (the ecological variables of interest; e.g. abundance or occurrence of a species) should be set based on the needs of that framework (Nichols and Williams 2006; e.g. Chapters 2–4). Once such monitoring targets are set, the subsequent step in monitoring design involves consideration of the field and analytical methods that will be used to measure monitoring targets with adequate accuracy and precision. Long-term monitoring programs will involve replication of measurements over time, and possibly over space; that is, one location or each of multiple locations will be monitored multiple times, producing a collection of site visits (replicates). Clearly this replication is important for addressing spatial and temporal variability in the ecological resources of interest (Chapters 7–10), but it is worth considering how this replication can further be exploited to increase the effectiveness of monitoring. In particular, defensible monitoring of the majority of animal, and to a lesser degree plant, populations and communities will generally require investigators to account for imperfect detection (Chapters 4, 18). Raw indices of population state variables, such as abundance or occupancy (sensu MacKenzie et al. 2002), are rarely defensible when detection probabilities are challenges associated with estimating detection probabilities (e.g. McKelvey and Pearson 2001, Johnson 2008), we do not attempt to resolve this debate here. Rather, we are more apt to agree with MacKenzie and Kendall (2002) that the burden of proof ought to be on the assertion that detection probabilities are constant. Furthermore, given the wide variety of field methods available for estimating detection probabilities and the inability for an investigator to know, a priori, if detection probabilities will be

An algorithm for detecting trophic status (chlorophyll-a), cyanobacterial-dominance, surface scums and floating vegetation in inland and coastal waters

CSIR Research Space (South Africa)

Matthews, MW

2012-09-01

Full Text Available A novel algorithm is presented for detecting trophic status (chlorophyll-a), cyanobacterial blooms (cyano-blooms), surface scum and floating vegetation in coastal and inland waters using top-ofatmosphere data from the Medium Resolution Imaging...

Applied network security monitoring collection, detection, and analysis

CERN Document Server

Sanders, Chris

2013-01-01

Applied Network Security Monitoring is the essential guide to becoming an NSM analyst from the ground up. This book takes a fundamental approach to NSM, complete with dozens of real-world examples that teach you the key concepts of NSM. Network security monitoring is based on the principle that prevention eventually fails. In the current threat landscape, no matter how much you try, motivated attackers will eventually find their way into your network. At that point, it is your ability to detect and respond to that intrusion that can be the difference between a small incident and a major di

Variability in the mechanisms controlling Southern Ocean phytoplankton bloom phenology in an ocean model and satellite observations

Science.gov (United States)

Rohr, Tyler; Long, Matthew C.; Kavanaugh, Maria T.; Lindsay, Keith; Doney, Scott C.

2017-05-01

A coupled global numerical simulation (conducted with the Community Earth System Model) is used in conjunction with satellite remote sensing observations to examine the role of top-down (grazing pressure) and bottom-up (light, nutrients) controls on marine phytoplankton bloom dynamics in the Southern Ocean. Phytoplankton seasonal phenology is evaluated in the context of the recently proposed "disturbance-recovery" hypothesis relative to more traditional, exclusively "bottom-up" frameworks. All blooms occur when phytoplankton division rates exceed loss rates to permit sustained net population growth; however, the nature of this decoupling period varies regionally in Community Earth System Model. Regional case studies illustrate how unique pathways allow blooms to emerge despite very poor division rates or very strong grazing rates. In the Subantarctic, southeast Pacific small spring blooms initiate early cooccurring with deep mixing and low division rates, consistent with the disturbance-recovery hypothesis. Similar systematics are present in the Subantarctic, southwest Atlantic during the spring but are eclipsed by a subsequent, larger summer bloom that is coincident with shallow mixing and the annual maximum in division rates, consistent with a bottom-up, light limited framework. In the model simulation, increased iron stress prevents a similar summer bloom in the southeast Pacific. In the simulated Antarctic zone (70°S-65°S) seasonal sea ice acts as a dominant phytoplankton-zooplankton decoupling agent, triggering a delayed but substantial bloom as ice recedes. Satellite ocean color remote sensing and ocean physical reanalysis products do not precisely match model-predicted phenology, but observed patterns do indicate regional variability in mechanism across the Atlantic and Pacific.

Culturing Toxic Benthic Blooms: The Fate of Natural Biofilms in a Microcosm System

Directory of Open Access Journals (Sweden)

Francesca Di Pippo

2017-08-01

Full Text Available A microcosm designed for culturing aquatic phototrophic biofilms on artificial substrata was used to perform experiments with microphytobenthos sampled during summer toxic outbreaks of Ostreopsis cf. ovata along the Middle Tyrrhenian coast. This dynamic approach aimed at exploring the unique and complex nature of O. cf. ovata bloom development in the benthic system. Epibenthic assemblages were used as inocula for co-cultures of bloom organisms on polycarbonate slides at controlled environmental conditions. Biofilm surface adhesion, growth, and spatial structure were evaluated along with shifts in composition and matrix production in a low disturbance regime, simulating source habitat. Initial adhesion and substratum colonisation appeared as stochastic processes, then community structure and physiognomy markedly changed with time. Dominance of filamentous cyanobacteria and diatoms, and dense clusters of Amphidinium cf. carterae at the mature biofilm phases, were recorded by light and confocal microscopy, whilst O. cf. ovata growth was visibly limited in the late culture phases. Life-form strategies, competitiveness for resources, and possibly allelopathic interactions shaped biofilm structure during culture growth. HPLC (High Performance Liquid Chromatography analysis of exopolysaccharidic matrix revealed variations in sugar total amounts and composition. No toxic compounds were detected in the final communities tested by LC-MS (Liquid Chromatography- Mass Spectrometry and MALDI-TOF MS (Matrix Assisted Laser Desorption Ionization Time OF Flight Mass Spectroscopy techniques.

Multidrug-resistant tuberculosis treatment failure detection depends on monitoring interval and microbiological method

Science.gov (United States)

White, Richard A.; Lu, Chunling; Rodriguez, Carly A.; Bayona, Jaime; Becerra, Mercedes C.; Burgos, Marcos; Centis, Rosella; Cohen, Theodore; Cox, Helen; D'Ambrosio, Lia; Danilovitz, Manfred; Falzon, Dennis; Gelmanova, Irina Y.; Gler, Maria T.; Grinsdale, Jennifer A.; Holtz, Timothy H.; Keshavjee, Salmaan; Leimane, Vaira; Menzies, Dick; Milstein, Meredith B.; Mishustin, Sergey P.; Pagano, Marcello; Quelapio, Maria I.; Shean, Karen; Shin, Sonya S.; Tolman, Arielle W.; van der Walt, Martha L.; Van Deun, Armand; Viiklepp, Piret

2016-01-01

Debate persists about monitoring method (culture or smear) and interval (monthly or less frequently) during treatment for multidrug-resistant tuberculosis (MDR-TB). We analysed existing data and estimated the effect of monitoring strategies on timing of failure detection. We identified studies reporting microbiological response to MDR-TB treatment and solicited individual patient data from authors. Frailty survival models were used to estimate pooled relative risk of failure detection in the last 12 months of treatment; hazard of failure using monthly culture was the reference. Data were obtained for 5410 patients across 12 observational studies. During the last 12 months of treatment, failure detection occurred in a median of 3 months by monthly culture; failure detection was delayed by 2, 7, and 9 months relying on bimonthly culture, monthly smear and bimonthly smear, respectively. Risk (95% CI) of failure detection delay resulting from monthly smear relative to culture is 0.38 (0.34–0.42) for all patients and 0.33 (0.25–0.42) for HIV-co-infected patients. Failure detection is delayed by reducing the sensitivity and frequency of the monitoring method. Monthly monitoring of sputum cultures from patients receiving MDR-TB treatment is recommended. Expanded laboratory capacity is needed for high-quality culture, and for smear microscopy and rapid molecular tests. PMID:27587552

Enhancement of thermal blooming effect on free space propagation of high power CW laser beam

Science.gov (United States)

Kashef, Tamer M.; Mokhtar, Ayman M.; Ghoniemy, Samy A.

2018-02-01

In this paper, we present an enhanced model to predict the effect of thermal blooming and atmospheric turbulence, on high energy laser beams free space propagation. We introduce an implementation technique for the proposed mathematical models describing the effect of thermal blooming and atmospheric turbulence including wind blowing, and how it effect high power laser beam power, far field pattern, phase change effect and beam quality . An investigated model of adaptive optics was introduced to study how to improve the wave front and phase distortion caused by thermal blooming and atmospheric turbulence, the adaptive optics model with Actuator influence spacing 3 cm the that shows observed improvement in the Strehl ratio and in wave front and phase of the beam. These models was implemented using cooperative agents relying on GLAD software package. Without taking in consideration the effect of thermal blooming It was deduced that the beam at the source takes the Gaussian shape with uniform intensity distribution, we found that the beam converge on the required distance 4 km using converging optics, comparing to the laser beam under the effect of thermal blooming the far field pattern shows characteristic secondary blip and "sugar scoop" effect which is characteristic of thermal blooming. It was found that the thermal blooming causes the beam to steer many centimeters and to diverge beyond about 1.8 km than come to a focus at 4 km where the beam assumed to be focused on the required target. We assume that this target is moving at v = (4,-4) m/sec at distance 4 km and the wind is moving at v = (-10,-10) m/sec, it was found that the effect will be strongest when wind and target movement are at the same velocity. GLAD software is used to calculate the attenuation effects of the atmosphere as well as the phase perturbations due to temperature change in the air and effects caused as the beam crosses through the air due to wind and beam steering.

Heterotrophic bacterial responses to the winter–spring phytoplankton bloom in open waters of the NW Mediterranean

KAUST Repository

Gomes, Ana

2014-12-03

The response of planktonic heterotrophic prokaryotes to the NW Mediterranean winter–spring offshore phytoplankton bloom was assessed in 3 cruises conducted in March, April–May and September 2009. Bulk measurements of phytoplankton and bacterioplankton biomass and production were complemented with an insight into bacterial physiological structure by single-cell analysis of nucleic acid content [low (LNA) vs. high (HNA)] and membrane integrity (“Live” vs. “Dead” cells). Bacterial production empirical conversion factors (0.82±0.25 SE kg C mol leucine−1) were almost always well below the theoretical value. Major differences in most microbial variables were found among the 3 periods, which varied from extremely high phytoplankton biomass and production during the bloom in March (>1 g C m−2 d−1 primary production) to typically oligotrophic conditions during September stratification (<200 mg C m−2 d−1). In both these periods bacterial production was ~30 mg C m−2 d−1 while very large bacterial production (mean 228, with some stations exceeding 500 mg C m−2 d−1) but low biomass was observed during the April–May post-bloom phase. The contribution of HNA (30–67%) and “Live” cells (47–97%) were temporally opposite in the study periods, with maxima in March and September, respectively. Different relationships were found between physiological structure and bottom-up variables, with HNA bacteria apparently more responsive to phytoplankton only during the bloom, coinciding with larger average cell sizes of LNA bacteria. Moderate phytoplankton–bacterioplankton coupling of biomass and activity was only observed in the bloom and post-bloom phases, while relationships between both compartments were not significant under stratification. With all data pooled, bacteria were only weakly bottom-up controlled. Our analyses show that the biomass and production of planktonic algae and bacteria followed opposite paths in the transition from bloom to

1999 Leak Detection, Monitoring, and Mitigation Strategy Update

International Nuclear Information System (INIS)

OHL, P.C.

1999-01-01

This document is a complete revision of WHC-SD-WM-ES-378, Rev 1. This update includes recent developments in Leak Detection, Leak Monitoring, and Leak Mitigation technologies, as well as, recent developments in single-shell tank retrieval technologies. In addition, a single-shell tank retrieval release protection strategy is presented

Margalef's mandala and phytoplankton bloom strategies

Science.gov (United States)

Wyatt, Timothy

2014-03-01

Margalef's mandala maps phytoplankton species into a phase space defined by turbulence (A) and nutrient concentrations (Ni); these are the hard axes. The permutations of high and low A and high and low Ni divide the space into four domains. Soft axes indicate some ecological dynamics. A main sequence shows the normal course of phytoplankton succession; the r-K axis of MacArthur and Wilson runs parallel to it. An alternative successional sequence leads to the low A-high Ni domain into which many red tide species are mapped. Astronomical and biological time are implicit. A mathematical transformation of the mandala (rotation) links it to the classical bloom models of Sverdrup (time) and Kierstead and Slobodkin (space). Both rarity and the propensity to form red tides are considered to be species characters, meaning that maximum population abundance can be a target of natural selection. Equally, both the unpredictable appearance of bloom species and their short-lived appearances may be species characters. There may be a correlation too between these features and long-lived dormant stages in the life-cycle; then the vegetative planktonic phase is the 'weak link' in the life-cycle. Red tides are thus due to species which have evolved suites of traits which result in specific demographic strategies.

Dynamics of Bacterial and Fungal Communities during the Outbreak and Decline of an Algal Bloom in a Drinking Water Reservoir

Directory of Open Access Journals (Sweden)

Haihan Zhang

2018-02-01

Full Text Available The microbial communities associated with algal blooms play a pivotal role in organic carbon, nitrogen and phosphorus cycling in freshwater ecosystems. However, there have been few studies focused on unveiling the dynamics of bacterial and fungal communities during the outbreak and decline of algal blooms in drinking water reservoirs. To address this issue, the compositions of bacterial and fungal communities were assessed in the Zhoucun drinking water reservoir using 16S rRNA and internal transcribed spacer (ITS gene Illumina MiSeq sequencing techniques. The results showed the algal bloom was dominated by Synechococcus, Microcystis, and Prochlorothrix. The bloom was characterized by a steady decrease of total phosphorus (TP from the outbreak to the decline period (p < 0.05 while Fe concentration increased sharply during the decline period (p < 0.05. The highest algal biomass and cell concentrations observed during the bloom were 51.7 mg/L and 1.9×108 cell/L, respectively. The cell concentration was positively correlated with CODMn (r = 0.89, p = 0.02. Illumina Miseq sequencing showed that algal bloom altered the water bacterial and fungal community structure. During the bloom, the dominant bacterial genus were Acinetobacter sp., Limnobacter sp., Synechococcus sp., and Roseomonas sp. The relative size of the fungal community also changed with algal bloom and its composition mainly contained Ascomycota, Basidiomycota and Chytridiomycota. Heat map profiling indicated that algal bloom had a more consistent effect upon fungal communities at genus level. Redundancy analysis (RDA also demonstrated that the structure of water bacterial communities was significantly correlated to conductivity and ammonia nitrogen. Meanwhile, water temperature, Fe and ammonia nitrogen drive the dynamics of water fungal communities. The results from this work suggested that water bacterial and fungal communities changed significantly during the outbreak and decline of

Vibration-Based Adaptive Novelty Detection Method for Monitoring Faults in a Kinematic Chain

Directory of Open Access Journals (Sweden)

Jesus Adolfo Cariño-Corrales

2016-01-01

Full Text Available This paper presents an adaptive novelty detection methodology applied to a kinematic chain for the monitoring of faults. The proposed approach has the premise that only information of the healthy operation of the machine is initially available and fault scenarios will eventually develop. This approach aims to cover some of the challenges presented when condition monitoring is applied under a continuous learning framework. The structure of the method is divided into two recursive stages: first, an offline stage for initialization and retraining of the feature reduction and novelty detection modules and, second, an online monitoring stage to continuously assess the condition of the machine. Contrary to classical static feature reduction approaches, the proposed method reformulates the features by employing first a Laplacian Score ranking and then the Fisher Score ranking for retraining. The proposed methodology is validated experimentally by monitoring the vibration measurements of a kinematic chain driven by an induction motor. Two faults are induced in the motor to validate the method performance to detect anomalies and adapt the feature reduction and novelty detection modules to the new information. The obtained results show the advantages of employing an adaptive approach for novelty detection and feature reduction making the proposed method suitable for industrial machinery diagnosis applications.

Greener on the Other Side: How Increased Urea Use may Promote Cyanobacterial Blooms

Science.gov (United States)

Erratt, K. J.; Creed, I. F.; Trick, C. G.

2017-12-01

The frequency of freshwater cyanobacterial blooms is on the rise in temperate regions around the world. The widespread use of chemical fertilizers linked to modern agricultural practices has enhanced the fertility of surface waters promoting the expansion of cyanobacteria dominated harmful algal blooms. While phosphorus (P) has been recognized as the principal agent regulating phytoplankton productivity in inland waters, elevated P is not the universal trigger for bloom initiation. P fertilizer applications across the globe have been outpaced by nitrogen (N) fertilizer use. Not only has the load of N entering surface waters increased, but its chemical composition has been altered. The use of inorganic-N fertilizers has been waned in favor of urea-based products, with urea now accounting for more than half of total N-fertilizer applications worldwide. This contemporary shift in fertilizer usage has coincided with the rise of cyanobacteria dominated harmful algal blooms in freshwaters. Here, we examined the relative success of urea as a N-source relative to inorganic N forms (NO3-, NH4+) for three common bloom-forming species of cyanobacteria: Microcystis aeruginosa, Dolichospermum flos-aque, and Synechococcus sp. We found that (1) urea was consistently drawdown more rapidly relative to inorganic N substrates, suggesting that cyanobacteria exhibit a preference for urea over inorganic N forms; (2) cyanobacteria consume urea in excess of cellular requirements; and (3) urea may offer cyanobacteria a competitive edge over eukaryotic algae by enhancing light absorption capabilities. As we push forward into the 21st century, our reliance on urea-based fertilizers is projected to escalate and it is critical that we understand the unintended consequences urea discharge could be having on receiving freshwaters.

Mitigating cyanobacterial blooms: how effective are 'effective microorganisms'?

NARCIS (Netherlands)

Lürling, M.F.L.L.W.; Tolman, Y.; Euwe, M.

2009-01-01

This study examined the effects of 'Effective Microorganisms (EM)' on the growth of cyanobacteria, and their ability to terminate cyanobacterial blooms. The EM was tested in the form of 'mudballs' or 'Bokashi-balls', and as a suspension (EM-A) in laboratory experiments. No growth inhibition was

Ocean colour remote sensing of harmful algal blooms in the Benguela system

CSIR Research Space (South Africa)

Bernard, S

2014-01-01

Full Text Available mortalities of tons of rock lobster and other marine life (Cockcroft et al., 2000). Other ecosystem impacts may be more subtle and difficult to quantify, and may include altered food web interac-tions and habitats. The poor food source provided by blooms... as afforded by the bloom resulted in anoxia through the entire water column. Large fish and lobster mortalities were consequently observed off the Berg River estuary and adjacent beaches on the 5 May 2009. Termination of the boom was as...

IMPROVING CYANOBACTERIA AND CYANOTOXIN MONITORING IN SURFACE WATERS FOR DRINKING WATER SUPPLY

Directory of Open Access Journals (Sweden)

Jing Li

2017-06-01

Full Text Available Cyanobacteria in fresh water can cause serious threats to drinking water supplies. Managing cyanobacterial blooms particularly at small drinking water treatment plants is challenging. Because large amount of cyanobacteria may cause clogging in the treatment process and various cyanotoxins are hard to remove, while they may cause severe health problems. There is lack of instructions of what cyanobacteria/toxin amount should trigger what kind of actions for drinking water management except for Microcystins. This demands a Cyanobacteria Management Tool (CMT to help regulators/operators to improve cyanobacteria/cyanotoxin monitoring in surface waters for drinking water supply. This project proposes a CMT tool, including selecting proper indicators for quick cyanobacteria monitoring and verifying quick analysis methods for cyanobacteria and cyanotoxin. This tool is suggested for raw water management regarding cyanobacteria monitoring in lakes, especially in boreal forest climate. In addition, it applies to regions that apply international WHO standards for water management. In Swedish context, drinking water producers which use raw water from lakes that experience cyanobacterial blooms, need to create a monitoring routine for cyanobacteria/cyanotoxin and to monitor beyond such as Anatoxins, Cylindrospermopsins and Saxitoxins. Using the proposed CMT tool will increase water safety at surface water treatment plants substantially by introducing three alerting points for actions. CMT design for each local condition should integrate adaptive monitoring program.

Intense blooms of Trichodesmium erythraeum (Cyanophyta) in the open waters along east coast of India

Digital Repository Service at National Institute of Oceanography (India)

Jyothibabu, R.; Madhu, N.V.; Murukesh, N.; Haridas, P.; Nair, K.K.C.; Venugopal, P.

° 44'N, 89° 04'), both along east coast of India. Nutrients (nitrate, phosphate, silicate) concentration in the upper 30 m of the water column showed very low values. High-integrated primary production (Bloom 1- 2160 mgC m-2 d-1, Bloom 2-1740 mgC m-2 d...

PRE-SERVICE MATHEMATICS TEACHERS’ CONCEPTION OF HIGHER-ORDER THINKING LEVEL IN BLOOM'S TAXONOMY

OpenAIRE

Damianus D Samo

2017-01-01

The purpose of this study is to explore pre-service mathematics teachers' conception of higher-order thinking in Bloom's Taxonomy, to explore pre-service mathematics teachers' ability in categorizing six cognitive levels of Bloom's Taxonomy as lower-order thinking and higher-order thinking, and pre-service mathematics teachers' ability in identifying some questionable items as lower-order and higher-order thinking. The higher-order thinking is the type of non-algorithm thinking which include ...

Spatial Outlier Detection of CO2 Monitoring Data Based on Spatial Local Outlier Factor

OpenAIRE

Liu Xin; Zhang Shaoliang; Zheng Pulin

2015-01-01

Spatial local outlier factor (SLOF) algorithm was adopted in this study for spatial outlier detection because of the limitations of the traditional static threshold detection. Based on the spatial characteristics of CO2 monitoring data obtained in the carbon capture and storage (CCS) project, the K-Nearest Neighbour (KNN) graph was constructed using the latitude and longitude information of the monitoring points to identify the spatial neighbourhood of the monitoring points. Then ...

El Niño-related offshore phytoplankton bloom events around the Spratley Islands in the South China Sea

Science.gov (United States)

Isoguchi, Osamu; Kawamura, Hiroshi; Ku-Kassim, Ku-Yaacob

2005-11-01

Satellite chlorophyll-a (Chl-a) observations reveal offshore phytoplankton bloom events with high Chl-a (>1 mg m-3) spreading over 300 km off the coasts around the Spratley Islands in the South China Sea (SCS) during the spring of 1998. The bloom entails anomalous wind jet and sea surface temperature (SST) cooling, suggesting that the wind jet-induced mixing and/or offshore upwelling bring about the cooling and the bloom through the supply of nutrient-rich waters into the euphotic zone. The strong wind jet is orographically formed responding to shifts in wind direction over the eastern SCS. The wind shift is connected with the Philippine Sea anomalous anticyclone that is established during El Niño, indicating the El Niño-related offshore bloom. The long-term reanalysis winds over the eastern SCS demonstrates that wind jet formation and associated offshore cooling/bloom are expected to occur in most cases of the subsequent El Niño years.

Biomanipulation with quagga mussels (Dreissena rostriformis bugensis) to control harmful algal blooms in eutrophic urban ponds

NARCIS (Netherlands)

Waajen, Guido W. A. M.; Van Bruggen, Niek C. B.; Pires, L. Miguel Dionisio; Lengkeek, Wouter; Lurling, Miquel

Many urban ponds in The Netherlands and other countries suffer from eutrophication, resulting in harmful algal blooms which are often dominated by cyanobacteria. A sufficient reduction of nutrients, as prerequisite to mitigate cyanobacterial blooms in urban ponds, is not always feasible. Water

Biomanipulation with quagga mussels (Dreissena rostriformis bugensis) to control harmful algal blooms in eutrophic urban ponds

NARCIS (Netherlands)

Waajen, Guido W.A.M.; Bruggen, Van Niek C.B.; Pires, Miguel Dionisio L.; Lengkeek, Wouter; Lurling, Miguel

2016-01-01

Many urban ponds in The Netherlands and other countries suffer from eutrophication, resulting in harmful algal blooms which are often dominated by cyanobacteria. A sufficient reduction of nutrients, as prerequisite to mitigate cyanobacterial blooms in urban ponds, is not always feasible. Water

Early detection monitoring for larval dreissenid mussels: how much plankton sampling is enough?

Science.gov (United States)

Counihan, Timothy D; Bollens, Stephen M

2017-03-01

The development of quagga and zebra mussel (dreissenids) monitoring programs in the Pacific Northwest provides a unique opportunity to evaluate a regional invasive species detection effort early in its development. Recent studies suggest that the ecological and economic costs of a dreissenid infestation in the Pacific Northwest of the USA would be significant. Consequently, efforts are underway to monitor for the presence of dreissenids. However, assessments of whether these efforts provide for early detection are lacking. We use information collected from 2012 to 2014 to characterize the development of larval dreissenid monitoring programs in the states of Idaho, Montana, Oregon, and Washington in the context of introduction and establishment risk. We also estimate the effort needed for high-probability detection of rare planktonic taxa in four Columbia and Snake River reservoirs and assess whether the current level of effort provides for early detection. We found that the effort expended to monitor for dreissenid mussels increased substantially from 2012 to 2014, that efforts were distributed across risk categories ranging from high to very low, and that substantial gaps in our knowledge of both introduction and establishment risk exist. The estimated volume of filtered water required to fully census planktonic taxa or to provide high-probability detection of rare taxa was high for the four reservoirs examined. We conclude that the current level of effort expended does not provide for high-probability detection of larval dreissenids or other planktonic taxa when they are rare in these reservoirs. We discuss options to improve early detection capabilities.

Long distance high power optical laser fiber break detection and continuity monitoring systems and methods

Science.gov (United States)

Rinzler, Charles C.; Gray, William C.; Faircloth, Brian O.; Zediker, Mark S.

2016-02-23

A monitoring and detection system for use on high power laser systems, long distance high power laser systems and tools for performing high power laser operations. In particular, the monitoring and detection systems provide break detection and continuity protection for performing high power laser operations on, and in, remote and difficult to access locations.

Nutrient control of cyanobacterial blooms in the Baltic Sea

NARCIS (Netherlands)

Stal, L.J.; Staal, M.J.; Villbrandt, M.

1999-01-01

Cyanobacterial blooms in the Baltic Sea were investigated with respect to growth Limitation and nitrogen fixation. The community was composed predominantly of Synechococcus spp., and large, heterocystous, nitrogen-fixing cyanobacteria (Aphanizomenon spp, and Nodularia spp.), that usually formed

Occurrence of Ceratium furcoides (Levander) Langhans 1925 bloom at the Billings Reservoir, São Paulo State, Brazil.

Science.gov (United States)

Matsumura-Tundisi, T; Tundisi, J G; Luzia, A P; Degani, R M

2010-10-01

An unusual bloom of Ceratium furcoides is reported for a station of the Taquacetuba compartment of the Billings Reservoir. The appearance of this bloom is attributed to the mixing and turbulence of the water column that removed Ceratium cysts from the surface of the sediment and promoted conditions for the growth of this species in the region of mixing. Cold fronts approaching the Billings Reservoir are probably the cause of the mixing and bloom. Also turbulence induced by wind increased phosphorus concentration in the water column. Ceratium furcoides was the dominant species at station 1 where the nutrient concentrations of nitrogen and phosphorus were high. Ceratium spp. blooms may be a problem for water treatment and massive mortality can affect the dissolved oxygen of the water producing fish kill.

Bio-optic characterization of Discosphaera tubifer bloom occurs in an overcrowded fishing harbour at Veraval, India.

Science.gov (United States)

Mandal, Subir Kumar; Patel, Vipul R; Temkar, Ganesh; George, Basil M; Raman, Mini

2015-09-01

Discosphaera tubifer, a coccolithophore has been first time reported as a bloom-forming organism from an over-crowded fishing harbour at Veraval, west coast of India. Physiochemical and optical parameters were measured following standard protocols. Average concentration of inorganic nutrients, such as NO2-N (17.26 ± 2.92 μM), NO3-N (643.80 ± 215.99 μM), PO4-P (74.10 ± 26.52 μM) and SiO3-Si (137.66 ± 25.83 μM) were recorded as very high at Veraval port as compared to other coastal stations i.e., 1.48 ± 0.66, 49.16 ± 13.73, 10.03 ± 5.31 and 96.23 ± 22.74 μM, respectively. The pH and salinity (‰) were observed to be low (7.80 ± 0.15 and 28.00 ± 4.54 ‰) as compared to coastal seawaters (8.34 ± 0.06 and 33.24 ± 2.32 ‰). Scanning electron microscopy (SEM) and spectral signature (absorbance and reflectance) study revealed that the bloom-forming organism was D. tubifer. High-performance liquid chromatography (HPLC) study detected that chlorophyllide-a represent nearly 47.53 % of total pigment composition followed by chlorophyll c2 (27.40 %) and chlorophyll c3 (14.25 %). Four prominent absorption peaks were observed within 350 to 700 nm. The first peak was very wide and ranged from 350 to 530 nm and the rest of the three peaks ranged from 550 to 590, 590 to 650 and 650 to 690 nm, respectively. In case of reflection, three peaks appeared between 550 and 590, 590 and 630 and 630 and 670 nm. Nearly 100 % reflection was observed after 720 nm. The eutrophic condition of the port water along with low salinity and low pH might be the reason for D. tubifer bloom formation. This species-specific spectral signature of the D. tubifer bloom may be helpful for developing algorithm of remote sensing data analysis.

Dealing with incomplete and variable detectability in multi-year, multi-site monitoring of ecological populations

Science.gov (United States)

Converse, Sarah J.; Royle, J. Andrew; Gitzen, Robert A.; Millspaugh, Joshua J.; Cooper, Andrew B.; Licht, Daniel S.

2012-01-01

An ecological monitoring program should be viewed as a component of a larger framework designed to advance science and/or management, rather than as a stand-alone activity. Monitoring targets (the ecological variables of interest; e.g. abundance or occurrence of a species) should be set based on the needs of that framework (Nichols and Williams 2006; e.g. Chapters 2–4). Once such monitoring targets are set, the subsequent step in monitoring design involves consideration of the field and analytical methods that will be used to measure monitoring targets with adequate accuracy and precision. Long-term monitoring programs will involve replication of measurements over time, and possibly over space; that is, one location or each of multiple locations will be monitored multiple times, producing a collection of site visits (replicates). Clearly this replication is important for addressing spatial and temporal variability in the ecological resources of interest (Chapters 7–10), but it is worth considering how this replication can further be exploited to increase the effectiveness of monitoring. In particular, defensible monitoring of the majority of animal, and to a lesser degree plant, populations and communities will generally require investigators to account for imperfect detection (Chapters 4, 18). Raw indices of population state variables, such as abundance or occupancy (sensu MacKenzie et al. 2002), are rarely defensible when detection probabilities are failing to correct for differences in detection, resulting in indices that have an unknown relationship to the parameters of interest (e.g. Nichols 1992, Anderson 2001, MacKenzie et al. 2002, Williams et al. 2002, Anderson 2003, White 2005, Kéry and Schmidt 2008). While others have argued that indices may be preferable in some cases due to the challenges associated with estimating detection probabilities (e.g. McKelvey and Pearson 2001, Johnson 2008), we do not attempt to resolve this debate here. Rather, we are

Leak detection in steam generators with hydrogen monitors using diffusion membranes

Energy Technology Data Exchange (ETDEWEB)

Hissink, M

1975-07-01

Large water leaks in steam-generators give rise to violent chemical reactions which can only be controlled by a pressure relief system. Smaller leaks do not pose direct safety hazards but wastage of pipes surrounding the leak should be prevented. Leak detection is best carried out by monitors recording the hydrogen in sodium content. For large leaks the specification of these monitors causes no problems, contrary to those for the timely detection of small leaks. Essential parameters are sensitivity and speed of response, specificity is less important. But apart from the instrument specification, a number of factors, related to the construction and operation of the steam-generator, determine the performance of the leak detection system. A discussion of these factors is given, with a view to the design of the SNR-300. Although tile results of many theoretical studies and experimental work are available, there seems to be room for further investigations on the growths of minor leaks. Also lacking a sufficient experience concerning the level and fluctuations of the hydrogen background in the sodium. A description is given of the hydrogen monitor developed at TNO, which is based on a combination of a nickel membrane and an ion getter pump. The parameters of this instrument have been evaluated in a test rig. Operational experience with the monitor is available from the 50 MW Test Facility at Hengelo. Especially for further studies the need for a calibrated instrument has become apparent. Test are going on with a modified design of a monitor meeting this requirement. (author)

Bacterial and protist community changes during a phytoplankton bloom

KAUST Repository

Pearman, John K.; Casas, Laura; Merle, Tony; Michell, Craig; Irigoien, Xabier

2015-01-01

)] as well as a control. This approach allowed us to discriminate the changes in species composition across a broad range of phylogenetic groups using a common taxonomic level. Diatoms dominated the bloom in the NPSc treatment while dinoflagellates were

Dynamics of Bacterial and Fungal Communities during the Outbreak and Decline of an Algal Bloom in a Drinking Water Reservoir.

Science.gov (United States)

Zhang, Haihan; Jia, Jingyu; Chen, Shengnan; Huang, Tinglin; Wang, Yue; Zhao, Zhenfang; Feng, Ji; Hao, Huiyan; Li, Sulin; Ma, Xinxin

2018-02-18

The microbial communities associated with algal blooms play a pivotal role in organic carbon, nitrogen and phosphorus cycling in freshwater ecosystems. However, there have been few studies focused on unveiling the dynamics of bacterial and fungal communities during the outbreak and decline of algal blooms in drinking water reservoirs. To address this issue, the compositions of bacterial and fungal communities were assessed in the Zhoucun drinking water reservoir using 16S rRNA and internal transcribed spacer (ITS) gene Illumina MiSeq sequencing techniques. The results showed the algal bloom was dominated by Synechococcus, Microcystis, and Prochlorothrix. The bloom was characterized by a steady decrease of total phosphorus (TP) from the outbreak to the decline period (p Limnobacter sp., Synechococcus sp., and Roseomonas sp. The relative size of the fungal community also changed with algal bloom and its composition mainly contained Ascomycota, Basidiomycota and Chytridiomycota. Heat map profiling indicated that algal bloom had a more consistent effect upon fungal communities at genus level. Redundancy analysis (RDA) also demonstrated that the structure of water bacterial communities was significantly correlated to conductivity and ammonia nitrogen. Meanwhile, water temperature, Fe and ammonia nitrogen drive the dynamics of water fungal communities. The results from this work suggested that water bacterial and fungal communities changed significantly during the outbreak and decline of algal bloom in Zhoucun drinking water reservoir. Our study highlights the potential role of microbial diversity as a driving force for the algal bloom and biogeochemical cycling of reservoir ecology.

Use of phosphorus to reduce blooms of the benthic diatom Didymosphenia geminata in an oligotrophic stream

Science.gov (United States)

James, Daniel A.; Bothwell, Max L.; Chipps, Steven R.; Carreiro, John

2015-01-01

Blooms of the benthic alga, Didymosphenia geminata [Lyngbye (Schmidt)], were first documented in Rapid Creek, South Dakota, in 2002 and have since been associated with changes to aquatic resources. Low concentration of P has been associated with D. geminata stalk development (i.e., blooms), so we considered elevating P as a possible method to reduce D. geminata blooms. We conducted 2 whole-stream P-enrichment experiments in Rapid Creek during 2007 and 2008. Enrichment with a slow-release fertilizer (Osmocote®: 14-14-14) in 2007 significantly reduced D. geminata blooms (indexed by D. geminata biomass) compared to upstream control sites. The reduction in biomass was less pronounced as distance from the enrichment source increased, a result indicating that P augmentation effectively decreased D. geminata biomass. In 2008, we implemented a before-after–control-impact (BACI) study to assess effects of a quick-release fertilizer (MAP: 11-52-0) on D. geminata biomass. The addition of 6 μg/L P to Rapid Creek resulted in a significant decrease in D. geminata biomass within 0.6 km downstream of the nutrient-addition point. Effects on D. geminata biomass were not evident further downstream. This study provides evidence to support the hypothesis that low P concentration regulates D. geminata blooms.

Establishing the link between Ostreopsis cf.ovata blooms and human health impacts using ecology and epidemiology

Directory of Open Access Journals (Sweden)

Magda Vila

2016-09-01

Full Text Available Blooms of the benthic dinoflagellate Ostreopsis have been related to sporadic acute respiratory symptoms and general malaise in people exposed to marine aerosols on some Mediterranean beaches. However, the direct link between recurrent Ostreopsis blooms and health problems has not been clearly established. In order to establish and elucidate the connection, we conducted a joint ecology and epidemiology study in an Ostreopsis hot spot. Throughout the bloom, which extended from the end of June until the end of October 2013, 81% of the human cohort that we studied experienced at least one Ostreopsis-related symptom. Paradoxically, the time when the effects were greatest was during a short time window in early August. This corresponded to the transition from the exponential growth to the stationary phase of the bloom. Negligible symptoms were reported from August to mid-October, during the stationary period of the proliferation, when O. cf. ovata maintained high concentrations of epiphytic cells. No clear patterns in the landward wind component were noted during the time when health effects were greatest. Our main hypothesis is that the irritants present in the aerosol are produced during a particular physiological phase of the Ostreopsis cells during the bloom.

Biological control of Microcystis dominated harmful algal blooms ...

African Journals Online (AJOL)

Freshwater resources are now threatened by the presence and increase of harmful algal blooms (HAB) all over the world. The HABs are sometimes a direct result of anthropogenic pollution entering water bodies, such as partially treated nutrient-rich effluents and the leaching of fertilisers and animal wastes. The impact of ...

Timing of migratory baleen whales at the Azores in relation to the North Atlantic spring bloom

NARCIS (Netherlands)

Visser, F.; Hartman, K.L.; Pierce, G.J.; Valavanis, V.D.; Huisman, J.

2011-01-01

Each year, a phytoplankton spring bloom starts just north of the North Atlantic Subtropical Gyre, and then expands northwards across the entire North Atlantic. Here, we investigate whether the timing of the spring migration of baleen whales is related to the timing of the phytoplankton spring bloom,

Cardiac monitoring for detection of atrial fibrillation after TIA: A systematic review and meta-analysis.

Science.gov (United States)

Korompoki, Eleni; Del Giudice, Angela; Hillmann, Steffi; Malzahn, Uwe; Gladstone, David J; Heuschmann, Peter; Veltkamp, Roland

2017-01-01

Background and purpose The detection rate of atrial fibrillation has not been studied specifically in transient ischemic attack (TIA) patients although extrapolation from ischemic stroke may be inadequate. We conducted a systematic review and meta-analysis to determine the rate of newly diagnosed atrial fibrillation using different methods of ECG monitoring in TIA. Methods A comprehensive literature search was performed following a pre-specified protocol the PRISMA statement. Prospective observational studies and randomized controlled trials were considered that included TIA patients who underwent cardiac monitoring for >12 h. Primary outcome was frequency of detection of atrial fibrillation ≥30 s. Analyses of subgroups and of duration and type of monitoring were performed. Results Seventeen studies enrolling 1163 patients were included. The pooled atrial fibrillation detection rate for all methods was 4% (95% CI: 2-7%). Yield of monitoring was higher in selected (higher age, more extensive testing for arrhythmias before enrolment, or presumed cardioembolic/cryptogenic cause) than in unselected cohorts (7% vs 3%). Pooled mean atrial fibrillation detection rates rose with duration of monitoring: 4% (24 h), 5% (24 h to 7 days) and 6% (>7 days), respectively. Yield of non-invasive was significantly lower than that of invasive monitoring (4% vs. 11%). Significant heterogeneity was observed among studies (I 2 =60.61%). Conclusion This first meta-analysis of atrial fibrillation detection in TIA patients finds a lower atrial fibrillation detection rate in TIA than reported for IS and TIA cohorts in previous meta-analyses. Prospective studies are needed to determine actual prevalence of atrial fibrillation and optimal diagnostic procedure for atrial fibrillation detection in TIA.

Detecting SYN flood attacks via statistical monitoring charts: A comparative study

KAUST Repository

Bouyeddou, Benamar

2017-12-14

Accurate detection of cyber-attacks plays a central role in safeguarding computer networks and information systems. This paper addresses the problem of detecting SYN flood attacks, which are the most popular Denial of Service (DoS) attacks. Here, we compare the detection capacity of three commonly monitoring charts namely, a Shewhart chart, a Cumulative Sum (CUSUM) control chart and exponentially weighted moving average (EWMA) chart, in detecting SYN flood attacks. The comparison study is conducted using the publicly available benchmark datasets: the 1999 DARPA Intrusion Detection Evaluation Datasets.

Algae Bloom in a Lake

Directory of Open Access Journals (Sweden)

David Sanabria

2008-01-01

Full Text Available The objective of this paper is to determine the likelihood of an algae bloom in a particular lake located in upstate New York. The growth of algae in this lake is caused by a high concentration of phosphorous that diffuses to the surface of the lake. Our calculations, based on Fick's Law, are used to create a mathematical model of the driving force of diffusion for phosphorous. Empirical observations are also used to predict whether the concentration of phosphorous will diffuse to the surface of this lake within a specified time and under specified conditions.

A method for examining temporal changes in cyanobacterial harmful algal bloom spatial extent using satellite remote sensing..

Science.gov (United States)

Cyanobacterial harmful algal blooms (CyanoHAB) are thought to be increasing globally over the past few decades, but relatively little quantitative information is available about the spatial extent of blooms. Satellite remote sensing provides a potential technology for identifying...

Un inusual bloom de Tetraselmis sp. en la Bahía de Valparaíso, Chile

OpenAIRE

PIZARRO, MARLENE; ITURRIAGA, RODOLFO; SILVA, ALEJANDRO; GALLEGOS, SONIA

2012-01-01

A bloom of Tetraselmis sp. was observed during the first days of January of 2006 in the Valparaiso Bay (32° 57'S; 71° 33'W), producing green coloration of sea and exclusion of phytoplankton species. Previous blooms of Tetraselmis sp. have not been observed in this bay.

Hydrodynamic control of microphytoplankton bloom in a coastal sea

Indian Academy of Sciences (India)

K Narasimha Murty

2017-08-31

Aug 31, 2017 ... surface water to depths in regions where there is no barrier layer at the ... ent availability (and light) alone does not give place to blooms in the ...... ics in a coastal upwelling system off southwestern Africa;. Deep Sea Res.

Transfer of seston lipids during a flagellate bloom from the surface to the benthic community in the Weddell Sea

Directory of Open Access Journals (Sweden)

Sergio Rossi

2013-09-01

Full Text Available Total lipid and fatty acid concentrations were studied in a late spring-early summer flagellate-dominated bloom in the Weddell Sea. These indicators were considered a good tool for assessing the quality of organic matter settling from surface to deep-water layers (epibenthic water layers. The results showed different patterns between the early (11-15 December 2003 and the late sampling period (18-27 December 2003 at all studied depths (5 m, 50 m and near-bottom water layers. Low phytoplankton biomass (mainly flagellates in the first half of the study corresponded to low total lipid and fatty acid concentrations. In the second sampling period a spring bloom (mainly flagellates and diatoms was detected, increasing the total lipid and fatty acid concentrations in the water column. The amount of settling organic matter from surface waters to the near-bottom water layers was high, especially in the late sampling period. Trophic markers showed evidence of a sink of available organic matter rich in quality and quantity, especially in terms of polyunsaturated fatty acids, for benthic organisms from surface layers to bottom layers in only a few days. The importance of studying short-time cycles in order to detect organic matter availability for benthic biota in view of the pulse-like dynamics of primary production in Antarctic waters is discussed.

A Data-Driven Monitoring Technique for Enhanced Fall Events Detection

KAUST Repository

Zerrouki, Nabil

2016-07-26

Fall detection is a crucial issue in the health care of seniors. In this work, we propose an innovative method for detecting falls via a simple human body descriptors. The extracted features are discriminative enough to describe human postures and not too computationally complex to allow a fast processing. The fall detection is addressed as a statistical anomaly detection problem. The proposed approach combines modeling using principal component analysis modeling with the exponentially weighted moving average (EWMA) monitoring chart. The EWMA scheme is applied on the ignored principal components to detect the presence of falls. Using two different fall detection datasets, URFD and FDD, we have demonstrated the greater sensitivity and effectiveness of the developed method over the conventional PCA-based methods.

Temporal pattern in the bloom-forming macroalgae Chaetomorpha linum and Ulva pertusa in seagrass beds, Swan Lake lagoon, North China

International Nuclear Information System (INIS)

Zhang, Xiaomei; Zhou, Yi; Liu, Peng; Wang, Feng; Liu, Bingjian; Liu, Xujia; Xu, Qiang; Yang, Hongsheng

2014-01-01

Highlights: • We conducted an annual survey of bloom-forming macroalgae in a lagoon. • C. linum biomass reached 1712 ± 780 g DW m −2 at the northern part of the lagoon. • Macroalgae δ 15 N values indicated a land-based source of N enrichment to the blooms. • High nutrient concentrations near the river mouth supported the blooms. • C. linum blooms induced the loss of seagrasses and benthic filter feeders. - Abstract: Seagrasses that are distributed over a large area of the Swan Lake, Weihai, China, support a productive ecosystem. In recent years, however, frequent macroalgal blooms have changed the ecosystem structure and threatened the seagrasses. To understand the bloom-forming macroalgae we conducted a yearly field survey of Swan Lake. Results indicated that the macroalgae Chaetomorpha linum and Ulva pertusa both exhibited a much higher productivity and attained a greater maximum biomass (of 1712 ± 780 g DW m −2 and 1511 ± 555 g DW m −2 , respectively) than was the case for the seagrasses. The mean annual atomic ratios of C/N, C/P and N/P in C. linum were 14.31 ± 4.45, 402.82 ± 130.25, and 28.12 ± 2.08, respectively. The δ 15 N values (11.09 ± 0.91‰ for C. linum; 9.27 ± 2.83‰ for U. pertusa) indicated a land-based source of N enrichment to the macroalgal blooms. High concentrations of nitrogen and phosphorus in the lagoon, particularly near the river mouth, supported the blooms

Oceans and Human Health: Microplastics and Harmful Algal Bloom

International Nuclear Information System (INIS)

Sombrito, Elvira Z.

2015-01-01

Traditionally the focus of research and concern of environmental studies in the marine system is the impact of human activities in the ocean: the sources, distribution and fate of pollutants resulting from human activities. More recently, there has been recognition of the potential direct impact health can come from eating contaminated seafood, swimming in polluted water, and exposure to toxins from harmful algal blooms. This paper will present two areas of concern that illustrates the fact that the health of the oceans and the health of humans go hand in hand: chemical pollution from plastics in the ocean and harmful alga bloom. The nuclear methodologies than can be useful in these areas will also be introduced. It is hoped that through the recognition of the inter-dependence of the health of both humans and the oceans, efforts will be made to restore and preserve the oceans. (author)

Public Perception of Blue-Algae Bloom Risk in Hongze Lake of China

Science.gov (United States)

Huang, Lei; Sun, Kai; Ban, Jie; Bi, Jun

2010-05-01

In this work we characterize the public perception of one kind of ecological risk—blue-algae bloom in Hongze Lake, China, based on the psychometric paradigm method. In the first survey of May 2008, 300 respondents of Sihong County adjacent to Hongze Lake were investigated, with a total of 156 questionnaires returned. Then in a second survey of July 2008, 500 respondents from the same research area were investigated, with 318 questionnaires collected. This research firstly attempted to explore the local respondents’ degree of concern regarding ecological changes to Hongze Lake in the last ten years. Secondly, to explore the public perception of blue-algae bloom compared to three typical kinds of hazards including earthquake, nuclear power and public traffic. T-test was used to examine the difference of risk perception in these four hazards over time. The third part of this research, with demographic analysis and nonparametric statistical test, predicted the different groups of respondents’ willingness to accept (WTA) risk of blue-algae bloom in two surveys. Using multiple linear regression analysis, the risk perception model explained 28.3% of variance in the WTA blue-algae bloom risk. The variables of Knowledge, Social effect, Benefit, Controllability and Trust in government were significantly correlated with WTA, which implied that these variables were the main influencing factors explaining the respondents’ willingness to accept risk. The results would help the Chinese government to comprehend the public’s risk perception of the lake ecosystem, inducing well designed communication of risks with public and making effective mitigation policies to improve people’s rational risk judgment.

Under-Ice Phytoplankton Blooms Inhibited by Spring Convective Mixing in Refreezing Leads

Science.gov (United States)

Lowry, Kate E.; Pickart, Robert S.; Selz, Virginia; Mills, Matthew M.; Pacini, Astrid; Lewis, Kate M.; Joy-Warren, Hannah L.; Nobre, Carolina; van Dijken, Gert L.; Grondin, Pierre-Luc; Ferland, Joannie; Arrigo, Kevin R.

2018-01-01

Spring phytoplankton growth in polar marine ecosystems is limited by light availability beneath ice-covered waters, particularly early in the season prior to snowmelt and melt pond formation. Leads of open water increase light transmission to the ice-covered ocean and are sites of air-sea exchange. We explore the role of leads in controlling phytoplankton bloom dynamics within the sea ice zone of the Arctic Ocean. Data are presented from spring measurements in the Chukchi Sea during the Study of Under-ice Blooms In the Chukchi Ecosystem (SUBICE) program in May and June 2014. We observed that fully consolidated sea ice supported modest under-ice blooms, while waters beneath sea ice with leads had significantly lower phytoplankton biomass, despite high nutrient availability. Through an analysis of hydrographic and biological properties, we attribute this counterintuitive finding to springtime convective mixing in refreezing leads of open water. Our results demonstrate that waters beneath loosely consolidated sea ice (84-95% ice concentration) had weak stratification and were frequently mixed below the critical depth (the depth at which depth-integrated production balances depth-integrated respiration). These findings are supported by theoretical model calculations of under-ice light, primary production, and critical depth at varied lead fractions. The model demonstrates that under-ice blooms can form even beneath snow-covered sea ice in the absence of mixing but not in more deeply mixed waters beneath sea ice with refreezing leads. Future estimates of primary production should account for these phytoplankton dynamics in ice-covered waters.

Novelty detection methods for online health monitoring and post data analysis of turbopumps

International Nuclear Information System (INIS)

Lei Hu; Niaoqing, Hu; Xinpeng, Zhang; Fengshou, Gu; Ming, Gao

2013-01-01

As novelty detection works when only normal data are available, it is of considerable promise for health monitoring in cases lacking fault samples and prior knowledge. We present two novelty detection methods for health monitoring of turbopumps in large-scale liquid propellant rocket engines. The first method is the adaptive Gaussian threshold model. This method is designed to monitor the vibration of the turbopumps online because it has minimal computational complexity and is easy for implementation in real time. The second method is the one-class support vector machine (OCSVM) which is developed for post analysis of historical vibration signals. Via post analysis the method not only confirms the online monitoring results but also provides diagnostic results so that faults from sensors are separated from those actually from the turbopumps. Both of these two methods are validated to be efficient for health monitoring of the turbopumps.

Bioavailability of mineral-bound iron to a snow algae-bacteria co-culture and implications for albedo-altering snow algae blooms.

Science.gov (United States)

Harrold, Z R; Hausrath, E M; Garcia, A H; Murray, A E; Tschauner, O; Raymond, J; Huang, S

2018-01-26

Snow algae can form large-scale blooms across the snowpack surface and near-surface environments. These pigmented blooms can decrease snow albedo, increase local melt rates, and may impact the global heat budget and water cycle. Yet, underlying causes for the geospatial occurrence of these blooms remain unconstrained. One possible factor contributing to snow algae blooms is the presence of mineral dust as a micronutrient source. We investigated the bioavailability of iron (Fe) -bearing minerals, including forsterite (Fo 90 , Mg 1.8 Fe 0.2 SiO 4 ), goethite, smectite and pyrite as Fe sources for a Chloromonas brevispina - bacteria co-culture through laboratory-based experimentation. Fo 90 was capable of stimulating snow algal growth and increased the algal growth rate in otherwise Fe-depleted co-cultures. Fo 90 -bearing systems also exhibited a decrease in bacteria:algae ratios compared to Fe-depleted conditions, suggesting a shift in microbial community structure. The C. brevispina co-culture also increased the rate of Fo 90 dissolution relative to an abiotic control. Analysis of 16S rRNA genes in the co-culture identified Gammaproteobacteria , Betaprotoeobacteria and Sphingobacteria , all of which are commonly found in snow and ice environments. Archaea were not detected. Collimonas and Pseudomonas , which are known to enhance mineral weathering rates, comprised two of the top eight (> 1 %) OTUs. These data provide unequivocal evidence that mineral dust can support elevated snow algae growth under otherwise Fe-depleted growth conditions, and that snow algae can enhance mineral dissolution under these conditions. IMPORTANCE Fe, a key micronutrient for photosynthetic growth, is necessary to support the formation of high-density snow algae blooms. The laboratory experiments described herein allow for a systematic investigation of snow algae-bacteria-mineral interactions and their ability to mobilize and uptake mineral-bound Fe. Results provide unequivocal and

Loss of RMI2 Increases Genome Instability and Causes a Bloom-Like Syndrome.

Directory of Open Access Journals (Sweden)

Damien F Hudson

2016-12-01

Full Text Available Bloom syndrome is a recessive human genetic disorder with features of genome instability, growth deficiency and predisposition to cancer. The only known causative gene is the BLM helicase that is a member of a protein complex along with topoisomerase III alpha, RMI1 and 2, which maintains replication fork stability and dissolves double Holliday junctions to prevent genome instability. Here we report the identification of a second gene, RMI2, that is deleted in affected siblings with Bloom-like features. Cells from homozygous individuals exhibit elevated rates of sister chromatid exchange, anaphase DNA bridges and micronuclei. Similar genome and chromosome instability phenotypes are observed in independently derived RMI2 knockout cells. In both patient and knockout cell lines reduced localisation of BLM to ultra fine DNA bridges and FANCD2 at foci linking bridges are observed. Overall, loss of RMI2 produces a partially active BLM complex with mild features of Bloom syndrome.

Environmental Chemistry and Chemical Ecology of "Green Tide" Seaweed Blooms.

Science.gov (United States)

Van Alstyne, Kathryn L; Nelson, Timothy A; Ridgway, Richard L

2015-09-01

Green tides are large growths or accumulations of green seaweeds that have been increasing in magnitude and frequency around the world. Because green tides consist of vast biomasses of algae in a limited area and are often seasonal or episodic, they go through periods of rapid growth in which they take up large amounts of nutrients and dissolved gases and generate bioactive natural products that may be stored in the plants, released into the environment, or broken down during decomposition. As a result of the use and production of inorganic and organic compounds, the algae in these blooms can have detrimental impacts on other organisms. Here, we review some of the effects that green tides have on the chemistry of seawater and the effects of the natural products that they produce. As blooms are developing and expanding, algae in green tides take up inorganic nutrients, such as nitrate and ortho-phosphate, which can limit their availability to other photosynthetic organisms. Their uptake of dissolved inorganic carbon for use in photosynthesis can cause localized spikes in the pH of seawater during the day with concomitant drops in the pH at night when the algae are respiring. Many of the algae that form green-tide blooms produce allelopathic compounds, which are metabolites that affect other species. The best documented allelopathic compounds include dimethylsulfoniopropionate (DMSP), dopamine, and reactive oxygen species (ROS) and their breakdown products. DMSP and dopamine are involved in defenses against herbivores. Dopamine and ROS are released into seawater where they can be allelopathic or toxic to other organisms. Thus, these macroalgal blooms can have harmful effects on nearby organisms by altering concentrations of nutrients and dissolved gas in seawater and by producing and releasing allelopathic or toxic compounds. © The Author 2015. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved

The extended Kalman filter for forecast of algal bloom dynamics.

Science.gov (United States)

Mao, J Q; Lee, Joseph H W; Choi, K W

2009-09-01

A deterministic ecosystem model is combined with an extended Kalman filter (EKF) to produce short term forecasts of algal bloom and dissolved oxygen dynamics in a marine fish culture zone (FCZ). The weakly flushed FCZ is modelled as a well-mixed system; the tidal exchange with the outer bay is lumped into a flushing rate that is numerically determined from a three-dimensional hydrodynamic model. The ecosystem model incorporates phytoplankton growth kinetics, nutrient uptake, photosynthetic production, nutrient sources from organic fish farm loads, and nutrient exchange with a sediment bed layer. High frequency field observations of chlorophyll, dissolved oxygen (DO) and hydro-meteorological parameters (sampling interval Deltat=1 day, 2h, 1h, respectively) and bi-weekly nutrient data are assimilated into the model to produce the combined state estimate accounting for the uncertainties. In addition to the water quality state variables, the EKF incorporates dynamic estimation of algal growth rate and settling velocity. The effectiveness of the EKF data assimilation is studied for a wide range of sampling intervals and prediction lead-times. The chlorophyll and dissolved oxygen estimated by the EKF are compared with field data of seven algal bloom events observed at Lamma Island, Hong Kong. The results show that the EKF estimate well captures the nonlinear error evolution in time; the chlorophyll level can be satisfactorily predicted by the filtered model estimate with a mean absolute error of around 1-2 microg/L. Predictions with 1-2 day lead-time are highly correlated with the observations (r=0.7-0.9); the correlation stays at a high level for a lead-time of 3 days (r=0.6-0.7). Estimated algal growth and settling rates are in accord with field observations; the more frequent DO data can compensate for less frequent algal biomass measurements. The present study is the first time the EKF is successfully applied to forecast an entire algal bloom cycle, suggesting the

Quarry detection monitoring wells completion report WP-166

International Nuclear Information System (INIS)

1991-09-01

The purpose of this report is to document the activities undertaken during implementation of Work Package 166, Quarry Detection Monitoring Wells, for the Weldon Spring Site Remedial action project, Weldon Spring, Missouri. The subcontract specifications should be consulted for specific details regarding this work effort. Analytical parameters for soil samples collected for all but one borehole were analyzed for uranium, thorium, cyanide, nitroaromatics, and all Hazardous Substance List parameters including volatiles, semivolatiles, pesticides, polychlorinated biphenyls (PCBs) and metals. No soil samples were collected at other borehole as per specifications. With Z exceptions, uranium results for all boreholes sampled were at background levels. Nitroaromatics and cyanide were not detected in any of the samples collected. Volatile and semivolatile organics were not detected in the soil samples collected from the boreholes, with the exception of common lab contaminants such as methylene chloride, toluene, acetone, and pathalates. All metals results were either within their natural background ranges or below the detection limit of the instrument. PCB's were not detected within any of the boreholes. Pesticides detected (aldrin and methoxychlor) at one borehole near the surface may be attributed to previous spraying of pesticides on the highway right-of-way. In conclusion, the analytical results show that only uranium was detected in significant quantities; all other results were below the detection limit, very near the detection limit, or within natural background ranges. 1 fig

Hierarchical Leak Detection and Localization Method in Natural Gas Pipeline Monitoring Sensor Networks

OpenAIRE

Ning Yu; Renjian Feng; Jiangwen Wan; Yinfeng Wu; Yang Yu

2011-01-01

In light of the problems of low recognition efficiency, high false rates and poor localization accuracy in traditional pipeline security detection technology, this paper proposes a type of hierarchical leak detection and localization method for use in natural gas pipeline monitoring sensor networks. In the signal preprocessing phase, original monitoring signals are dealt with by wavelet transform technology to extract the single mode signals as well as characteristic parameters. In the initia...

Air Monitoring: New Advances in Sampling and Detection

Directory of Open Access Journals (Sweden)

Nicola Watson

2011-01-01

Full Text Available As the harmful effects of low-level exposure to hazardous organic air pollutants become more evident, there is constant pressure to improve the detection limits of indoor and ambient air monitoring methods, for example, by collecting larger air volumes and by optimising the sensitivity of the analytical detector. However, at the other end of the scale, rapid industrialisation in the developing world and growing pressure to reclaim derelict industrial land for house building is driving the need for air monitoring methods that can reliably accommodate very-high-concentration samples in potentially aggressive matrices. This paper investigates the potential of a combination of two powerful gas chromatography—based analytical enhancements—sample preconcentration/thermal desorption and time-of-flight mass spectrometry—to improve quantitative and qualitative measurement of very-low-(ppt level organic chemicals, even in the most complex air samples. It also describes new, practical monitoring options for addressing equally challenging high-concentration industrial samples.

Categorization of ber varieties in relation to blooming period, fruit setting and harvesting time

International Nuclear Information System (INIS)

Sharif, N.; Abbas, M.M.; Ishfaq, M.; Memon, N.U.N.

2013-01-01

Thirty four local Ber varieties were evaluated at Horticultural Research Institute AARI, Faisalabad, Horticultural Research Station Bahawalpur (Punjab) and Jujube Research Station, Tandojam (Sindh). Traits viz. total period of blooming (dates), peak period of blooming (dates), total period of fruit set (dates), peak period of fruit set (dates), total period of fruit harvest (dates), peak period of fruit harvest (dates), total flowering days, peak flowering days, total fruit setting days, peak fruit setting days, total harvesting days and peak harvesting days were studied. The results revealed significant differences in parameters studied except total period of blooming under Tandojam, Sindh conditions. Varieties were classified as early, mid and late season for both provinces. Local varieties had potential for further manipulation in terms of variety improvement to attract growers for extensive ber cultivations under changing global climatic scenario. (author)

Landsat change detection can aid in water quality monitoring

Science.gov (United States)

Macdonald, H. C.; Steele, K. F.; Waite, W. P.; Shinn, M. R.

1977-01-01

Comparison between Landsat-1 and -2 imagery of Arkansas provided evidence of significant land use changes during the 1972-75 time period. Analysis of Arkansas historical water quality information has shown conclusively that whereas point source pollution generally can be detected by use of water quality data collected by state and federal agencies, sampling methodologies for nonpoint source contamination attributable to surface runoff are totally inadequate. The expensive undertaking of monitoring all nonpoint sources for numerous watersheds can be lessened by implementing Landsat change detection analyses.

Coastal upwelling linked to toxic Pseudo-nitzschia australis blooms in Los Angeles coastal waters, 2005-2007

KAUST Repository

Schnetzer, Astrid; Jones, Burton; Schaffner, Rebecca A.; Cetinić, Ivona; Fitzpatrick, Elizabeth; Miller, Peter E.; Seubert, Erica L.; Caron, David A.

2013-01-01

Harmful algal blooms dominated by the diatom Pseudo-nitzschia spp. have become a perennial but variable event within surface waters near the greater Los Angeles area. Toxic blooms during spring seasons from 2005 to 2007 varied strongly in their overall toxicity and duration. Differences in bloom dynamics were linked to differences in storm-induced river discharge following episodic rain events and coastal upwelling, both major coastal processes that led to the injection of nutrients into coastal surface waters. Heavy river runoff during early 2005, a record-rainfall year, favored a phytoplankton community mainly comprised of algal taxa other than Pseudo-nitzschia. The spring bloom during 2005 was associated with low domoic acid surface concentrations and minor contributions of (mainly) P. delicatissima to the diatom assemblage. In contrast, highly toxic P. australis-dominated blooms during spring seasons of 2006 and 2007 were linked to strong upwelling events. River discharge quotas in 2006 and 2007, in contrast to 2005, fell well below annual averages for the region. Surface toxin levels were linked to colder, more saline (i.e. upwelled) water over the 3-year study, but no such consistent relationship between domoic acid levels and other physiochemical parameters, such as macronutrient concentrations or nutrient ratios, was observed. © The Author 2013. Published by Oxford University Press. All rights reserved.

Influence of Didymosphenia geminata blooms on prey composition and associated diet and growth of Brown Trout

Science.gov (United States)

James, Daniel A.; Chipps, Steven R.

2016-01-01

We compared diet, stomach fullness, condition, and growth of Brown Trout Salmo trutta among streams with or without blooms of the benthic diatom Didymosphenia geminata in the Black Hills, South Dakota. In Rapid Creek, where D. geminata blooms covered ∼30% of the stream bottom, Brown Trout consumed fewer ephemeropterans (6–8% by weight) than individuals from two stream sections that have not had D. geminatablooms (Castle and Spearfish creeks; 13–39% by weight). In contrast, dipterans (primarily Chironomidae) represented a larger percentage of Brown Trout diets from Rapid Creek (D. geminata blooms present; 16–28% dry weight) compared with diets of trout from streams without D. geminata blooms (6–19% dry weight). Diets of small Brown Trout (100–199 mm TL) reflected the invertebrate species composition in benthic stream samples; in Rapid Creek, ephemeropterans were less abundant whereas dipterans were more abundant than in streams without D. geminata blooms. Stomach fullness and condition of Brown Trout from Rapid Creek were generally greater than those of Brown Trout from other populations. Linkages among invertebrate availability, diet composition, and condition of Brown Trout support the hypothesis that changes in invertebrate assemblages associated with D. geminata (i.e., more Chironomidae) could be contributing to high recruitment success for small Brown Trout in Rapid Creek.

Coastal upwelling linked to toxic Pseudo-nitzschia australis blooms in Los Angeles coastal waters, 2005-2007

KAUST Repository

Schnetzer, Astrid

2013-06-10

Harmful algal blooms dominated by the diatom Pseudo-nitzschia spp. have become a perennial but variable event within surface waters near the greater Los Angeles area. Toxic blooms during spring seasons from 2005 to 2007 varied strongly in their overall toxicity and duration. Differences in bloom dynamics were linked to differences in storm-induced river discharge following episodic rain events and coastal upwelling, both major coastal processes that led to the injection of nutrients into coastal surface waters. Heavy river runoff during early 2005, a record-rainfall year, favored a phytoplankton community mainly comprised of algal taxa other than Pseudo-nitzschia. The spring bloom during 2005 was associated with low domoic acid surface concentrations and minor contributions of (mainly) P. delicatissima to the diatom assemblage. In contrast, highly toxic P. australis-dominated blooms during spring seasons of 2006 and 2007 were linked to strong upwelling events. River discharge quotas in 2006 and 2007, in contrast to 2005, fell well below annual averages for the region. Surface toxin levels were linked to colder, more saline (i.e. upwelled) water over the 3-year study, but no such consistent relationship between domoic acid levels and other physiochemical parameters, such as macronutrient concentrations or nutrient ratios, was observed. © The Author 2013. Published by Oxford University Press. All rights reserved.

A workplace air monitor for uranium particulate detection

International Nuclear Information System (INIS)

Sayers, J.E.; Monroe, F.E. Jr.; Smith, D.D.; Wallace, S.A.

1990-01-01

An air monitor has been developed at the Oak Ridge Y-12 Plant to sample the air in enriched uranium processing areas and to detect elevated particulate concentrations due to an upset condition. The monitor measures the alpha particle activity from material collected on 47-mm filter paper. Three energy windows are used to allow quantification of background activity from radon and thoron daughters and correction of their spillage into the uranium window. There is sufficient monitor memory to hold a history file of six days' activity from three sampling heads at 20-min status intervals. Alarm signals are activated if the absolute level of activity on a filter exceeds a predefined level, or if an excessively fast rate of buildup is occurring, which would cause the absolute level to be exceeded. This monitor was combined with an absolute particle counter and data were collected at a processing station where uranium dust is known to be present. The occurrence of high particle count activity in the 3.0-10.0-μ range was followed by increased alpha activity on the filter paper. This strong correlation has not been reported

Sedimentation of phytoplankton during a diatom bloom : Rates and mechanisms

DEFF Research Database (Denmark)

Kiørboe, Thomas; Hansen, J.L.S.; Alldredge, A.L.

1996-01-01

Phytoplankton blooms are uncoupled from grazing and are normally terminated by sedimentation. There are several potential mechanisms by which phytoplankton cells may settle out of the photic zone: sinking of individual cells or chains, coagulation of cells into aggregates with high settling...... velocities, settling of cells attached to marine snow aggregates formed from discarded larvacean houses or pteropod feeding webs, and packaging of cells into rapidly falling zooplankton fecal pellets. We quantified the relative significance of these different mechanisms during a diatom bloom in a temperate...... to marine snow aggregates formed from discarded larvacean houses, whereas settling of unaggregated cells was insignificant. Formation rates of phytoplankton aggregates by physical coagulation was very low, and losses by this mechanism were much less than 0.07 d(-1); phytoplankton aggregates were neither...

Termination of a toxic Alexandrium bloom with hydrogen peroxide

NARCIS (Netherlands)

Burson, A.; Matthijs, H.C.P.; Bruijne, de W.; Talens, R.; Hoogenboom, L.A.P.; Gerssen, A.; Visser, P.M.; Stomp, M.; Steur, K.; Scheppingen, van Y.; Huisman, J.

2014-01-01

The dinoflagellate Alexandrium ostenfeldii is a well-known harmful algal species that can potentially cause paralytic shellfish poisoning (PSP). Usually A. ostenfeldii occurs in low background concentrations only, but in August of 2012 an exceptionally dense bloom of more than 1 million cells L-1

A new approach for structural health monitoring by applying anomaly detection on strain sensor data

Science.gov (United States)

Trichias, Konstantinos; Pijpers, Richard; Meeuwissen, Erik

2014-03-01

Structural Health Monitoring (SHM) systems help to monitor critical infrastructures (bridges, tunnels, etc.) remotely and provide up-to-date information about their physical condition. In addition, it helps to predict the structure's life and required maintenance in a cost-efficient way. Typically, inspection data gives insight in the structural health. The global structural behavior, and predominantly the structural loading, is generally measured with vibration and strain sensors. Acoustic emission sensors are more and more used for measuring global crack activity near critical locations. In this paper, we present a procedure for local structural health monitoring by applying Anomaly Detection (AD) on strain sensor data for sensors that are applied in expected crack path. Sensor data is analyzed by automatic anomaly detection in order to find crack activity at an early stage. This approach targets the monitoring of critical structural locations, such as welds, near which strain sensors can be applied during construction and/or locations with limited inspection possibilities during structural operation. We investigate several anomaly detection techniques to detect changes in statistical properties, indicating structural degradation. The most effective one is a novel polynomial fitting technique, which tracks slow changes in sensor data. Our approach has been tested on a representative test structure (bridge deck) in a lab environment, under constant and variable amplitude fatigue loading. In both cases, the evolving cracks at the monitored locations were successfully detected, autonomously, by our AD monitoring tool.

The Unfortunate Consequences of Bloom's Taxonomy

Science.gov (United States)

Case, Roland

2013-01-01

The sequenced levels of thinking articulated in Bloom's original taxonomy (or in the multitude of subsequent variations) is the most widely known list in education. In addition to enduring popularity, it is arguably one of the most destructive theories in education. In this article, the author explains what makes it so damaging and how…

Mitigating Harmful Cyanobacterial Blooms in a Human- and Climatically-Impacted World

Directory of Open Access Journals (Sweden)

Hans W. Paerl

2014-12-01

Full Text Available Bloom-forming harmful cyanobacteria (CyanoHABs are harmful from environmental, ecological and human health perspectives by outcompeting beneficial phytoplankton, creating low oxygen conditions (hypoxia, anoxia, and by producing cyanotoxins. Cyanobacterial genera exhibit optimal growth rates and bloom potentials at relatively high water temperatures; hence, global warming plays a key role in their expansion and persistence. CyanoHABs are regulated by synergistic effects of nutrient (nitrogen:N and phosphorus:P supplies, light, temperature, vertical stratification, water residence times, and biotic interactions. In most instances, nutrient control strategies should focus on reducing both N and P inputs. Strategies based on physical, chemical (nutrient and biological manipulations can be effective in reducing CyanoHABs; however, these strategies are largely confined to relatively small systems, and some are prone to ecological and environmental drawbacks, including enhancing release of cyanotoxins, disruption of planktonic and benthic communities and fisheries habitat. All strategies should consider and be adaptive to climatic variability and change in order to be effective for long-term control of CyanoHABs. Rising temperatures and greater hydrologic variability will increase growth rates and alter critical nutrient thresholds for CyanoHAB development; thus, nutrient reductions for bloom control may need to be more aggressively pursued in response to climatic changes globally.

Damage Detection Sensitivity of a Vehicle-based Bridge Health Monitoring System

Science.gov (United States)

Miyamoto, Ayaho; Yabe, Akito; Lúcio, Válter J. G.

2017-05-01

As one solution to the problem for condition assessment of existing short and medium span (10-30m) reinforced/prestressed concrete bridges, a new monitoring method using a public bus as part of a public transit system (called “Bus monitoring system”) was proposed, along with safety indices, namely, “characteristic deflection”, which is relatively free from the influence of dynamic disturbances due to such factors as the roughness of the road surface, and a structural anomaly parameter. In this study, to evaluate the practicality of the newly developed bus monitoring system, it has been field-tested over a period of about four years by using an in-service fixed-route bus operating on a bus route in the city of Ube, Yamaguchi Prefecture, Japan. In here, although there are some useful monitoring methods for short and medium span bridges based on the qualitative or quantitative information, the sensitivity of damage detection was newly discussed for safety assessment based on long term health monitoring data. The verification results thus obtained are also described in this paper, and also evaluates the sensitivity of the “characteristic deflection”, which is a bridge (health) condition indicator used by the bus monitoring system, in damage detection. Sensitivity of “characteristic deflection” is verified by introducing artificial damage into a bridge that has ended its service life and is awaiting removal. Furthermore, the sensitivity of “characteristic deflection” is verified by 3D FEM analysis.

Development of anomaly detection models for deep subsurface monitoring

Science.gov (United States)

Sun, A. Y.

2017-12-01

Deep subsurface repositories are used for waste disposal and carbon sequestration. Monitoring deep subsurface repositories for potential anomalies is challenging, not only because the number of sensor networks and the quality of data are often limited, but also because of the lack of labeled data needed to train and validate machine learning (ML) algorithms. Although physical simulation models may be applied to predict anomalies (or the system's nominal state for that sake), the accuracy of such predictions may be limited by inherent conceptual and parameter uncertainties. The main objective of this study was to demonstrate the potential of data-driven models for leakage detection in carbon sequestration repositories. Monitoring data collected during an artificial CO2 release test at a carbon sequestration repository were used, which include both scalar time series (pressure) and vector time series (distributed temperature sensing). For each type of data, separate online anomaly detection algorithms were developed using the baseline experiment data (no leak) and then tested on the leak experiment data. Performance of a number of different online algorithms was compared. Results show the importance of including contextual information in the dataset to mitigate the impact of reservoir noise and reduce false positive rate. The developed algorithms were integrated into a generic Web-based platform for real-time anomaly detection.

A chronicle of a killer alga in the west: ecology, assessment, and management of Prymnesium parvum blooms

Science.gov (United States)

Roelke, D.L.; Barkoh, Aaron; Brooks, B.W.; Grover, J.P.; Hambright, K.D.; LaClaire, John W.; Moeller, Peter D.R.; Patino, Reynaldo

2015-01-01

Since the mid-1980s, fish-killing blooms ofPrymnesium parvum spread throughout the USA. In the south central USA, P. parvum blooms have commonly spanned hundreds of kilometers. There is much evidence that physiological stress brought on by inorganic nutrient limitation enhances toxicity. Other factors influence toxin production as well, such as stress experienced at low salinity and temperature. A better understanding of toxin production by P. parvum remains elusive and the identities and functions of chemicals produced are unclear. This limits our understanding of factors that facilitated the spread of P. parvum blooms. In the south central USA, not only is there evidence that the spread of blooms was controlled, in part, by migration limitation. But there are also observations that suggest changed environmental conditions, primarily salinity, facilitated the spread of blooms. Other factors that might have played a role include altered hydrology and nutrient loading. Changes in water hardness, herbicide use, system pH, and the presence of toxin-resistant and/or P. parvum-inhibiting plankton may also have played a role. Management of P. parvum in natural systems has yet to be attempted, but may be guided by successes achieved in small impoundments and mesocosm experiments that employed various chemical and hydraulic control approaches.

Optical Modeling of Spectral Backscattering and Remote Sensing Reflectance From Emiliania huxleyi Blooms

Directory of Open Access Journals (Sweden)

Griet Neukermans

2018-05-01

Full Text Available In this study we develop an analytical model for spectral backscattering and ocean color remote sensing of blooms of the calcifying phytoplankton species Emiliania huxleyi. Blooms of this coccolithophore species are ubiquitous and particularly intense in temperate and subpolar ocean waters. We first present significant improvements to our previous analytical light backscattering model for E. huxleyi coccoliths and coccospheres by accounting for the elliptical shape of coccoliths and the multi-layered coccosphere architecture observed on detailed imagery of E. huxleyi liths and coccospheres. Our new model also includes a size distribution function that closely matches measured E. huxleyi size distributions. The model for spectral backscattering is then implemented in an analytical radiative transfer model to evaluate the variability of spectral remote sensing reflectance with respect to changes in the size distribution of the coccoliths and during a hypothetical E. huxleyi bloom decay event in which coccospheres shed their liths. Our modeled remote sensing reflectance spectra reproduced well the bright milky turquoise coloring of the open ocean typically associated with the final stages of E. huxleyi blooms, with peak reflectance at a wavelength of 0.49 μm. Our results also show that the magnitude of backscattering from coccoliths when attached to or freed from the coccosphere does not differ much, contrary to what is commonly assumed, and that the spectral shape of backscattering is mainly controlled by the size and morphology of the coccoliths, suggesting that they may be estimated from spectral backscattering.

The fast expansion of Pyropia aquaculture in ;Sansha; regions should be mainly responsible for the Ulva blooms in Yellow Sea

Science.gov (United States)

Zhang, Jianheng; Zhao, Peng; Huo, Yuanzi; Yu, Kefeng; He, Peimin

2017-04-01

Massive Ulva blooms became an environmental disaster in the Yellow Sea from 2007 to 2015. In this study, field shipboard observations indicated that Ulva blooms originated in Pyropia aquaculture area, and the morphology of initial floating Ulva seaweed have the structure of rhizoid, which is similar with the attached Ulva on the Pyropia rafts. The spatial distribution of Ulva microscopic propagules in the southern Yellow Sea also supported that the blooms originated in the Pyropia aquaculture area. Besides, numerical model was used in this study, showing the origin of macroalgal blooms was traced to "Sansha" regions which accounted for almost 70% of the total Pyropia aquaculture area. We conclude that the significant biomass (4252 tons) of Ulva species on the Pyropia rafts during the harvesting season in "Sansha" regions played an important role in the early rapid development of blooms in the Yellow Sea.

Experimental investigation of leak detection using mobile distributed monitoring system

Science.gov (United States)

Chen, Jiang; Zheng, Junli; Xiong, Feng; Ge, Qi; Yan, Qixiang; Cheng, Fei

2018-01-01

The leak detection of rockfill dams is currently hindered by spatial and temporal randomness and wide monitoring range. The spatial resolution of fiber Bragg grating (FBG) temperature sensing technology is related to the distance between measuring points. As a result, the number of measuring points should be increased to ensure that the precise location of the leak is detected. However, this leads to a higher monitoring cost. Consequently, it is difficult to promote and apply this technology to effectively monitor rockfill dam leakage. In this paper, a practical mobile distributed monitoring system with dual-tubes is used by combining the FBG sensing system and hydrothermal cycling system. This dual-tube structure is composed of an outer polyethylene of raised temperature resistance heating pipe, an inner polytetrafluoroethylene tube, and a FBG sensor string, among which, the FBG sensor string can be dragged freely in the internal tube to change the position of the measuring points and improve the spatial resolution. In order to test the effectiveness of the system, the large-scale model test of concentrated leakage in 13 working conditions is carried out by identifying the location, quantity, and leakage rate of leakage passage. Based on Newton’s law of cooling, the leakage state is identified using the seepage identification index ζ v that was confirmed according to the cooling curve. Results suggested that the monitoring system shows high sensitivity and can improve the spatial resolution with limited measuring points, and thus better locate the leakage area. In addition, the seepage identification index ζ v correlated well with the leakage rate qualitatively.

Detection of Electronic Anklet Wearers’ Groupings throughout Telematics Monitoring

Directory of Open Access Journals (Sweden)

Paulo Lima Machado

2017-01-01

Full Text Available Ankle bracelets (anklets imposed by law to track convicted individuals are being used in many countries as an alternative to overloaded prisons. There are many different systems for monitoring individuals wearing such devices, and these electronic anklet monitoring systems commonly detect violations of circulation areas permitted to holders. In spite of being able to monitor individual localization, such systems do not identify grouping activities of the monitored individuals, although this kind of event could represent a real risk of further offenses planned by those individuals. In order to address such a problem and to help monitoring systems to be able to have a proactive approach, this paper proposes sensor data fusion algorithms that are able to identify such groups based on data provided by anklet positioning devices. The results from the proposed algorithms can be applied to support risk assessment in the context of monitoring systems. The processing is performed using geographic points collected by a monitoring center, and as result, it produces a history of groups with their members, timestamps, locations and frequency of meetings. The proposed algorithms are validated in various serial and parallel computing scenarios, and the correspondent results are presented and discussed. The information produced by the proposed algorithms yields to a better characterization of the monitored individuals and can be adapted to support decision-making systems used by authorities that are responsible for planning decisions regarding actions affecting public security.

Low-complexity R-peak detection in ECG signals: a preliminary step towards ambulatory fetal monitoring.

Science.gov (United States)

Rooijakkers, Michiel; Rabotti, Chiara; Bennebroek, Martijn; van Meerbergen, Jef; Mischi, Massimo

2011-01-01

Non-invasive fetal health monitoring during pregnancy has become increasingly important. Recent advances in signal processing technology have enabled fetal monitoring during pregnancy, using abdominal ECG recordings. Ubiquitous ambulatory monitoring for continuous fetal health measurement is however still unfeasible due to the computational complexity of noise robust solutions. In this paper an ECG R-peak detection algorithm for ambulatory R-peak detection is proposed, as part of a fetal ECG detection algorithm. The proposed algorithm is optimized to reduce computational complexity, while increasing the R-peak detection quality compared to existing R-peak detection schemes. Validation of the algorithm is performed on two manually annotated datasets, the MIT/BIH Arrhythmia database and an in-house abdominal database. Both R-peak detection quality and computational complexity are compared to state-of-the-art algorithms as described in the literature. With a detection error rate of 0.22% and 0.12% on the MIT/BIH Arrhythmia and in-house databases, respectively, the quality of the proposed algorithm is comparable to the best state-of-the-art algorithms, at a reduced computational complexity.

Didymosphenia geminata: Algal blooms in oligotrophic streams and rivers

Science.gov (United States)

Sundareshwar, P. V.; Upadhayay, S.; Abessa, M.; Honomichl, S.; Berdanier, B.; Spaulding, S. A.; Sandvik, C.; Trennepohl, A.

2011-05-01

In recent decades, the diatom Didymosphenia geminata has emerged as nuisance species in river systems around the world. This periphytic alga forms large “blooms” in temperate streams, presenting a counterintuitive result: the blooms occur primarily in oligotrophic streams and rivers, where phosphorus (P) availability typically limits primary production. The goal of this study is to examine how high algal biomass is formed under low P conditions. We reveal a biogeochemical process by which D. geminata mats concentrate P from flowing waters. First, the mucopolysaccaride stalks of D. geminata adsorb both iron (Fe) and P. Second, enzymatic and bacterial processes interact with Fe to increase the biological availability of P. We propose that a positive feedback between total stalk biomass and high growth rate is created, which results in abundant P for cell division. The affinity of stalks for Fe in association with iron-phosphorus biogeochemistry suggest a resolution to the paradox of algal blooms in oliogotrophic streams and rivers.

Natural and anthropogenic nitrogen uptake by bloom-forming macroalgae

International Nuclear Information System (INIS)

Thornber, Carol S.; DiMilla, Peter; Nixon, Scott W.; McKinney, Richard A.

2008-01-01

The frequency and duration of macroalgal blooms have increased in many coastal waters over the past several decades. We used field surveys and laboratory culturing experiments to examine the nitrogen content and δ 15 N values of Ulva and Gracilaria, two bloom-forming algal genera in Narragansett Bay, RI (USA). The northern end of this bay is densely populated with large sewage treatment plant nitrogen inputs; the southern end is more lightly populated and opens to the Atlantic Ocean. Field-collected Ulva varied in δ 15 N among sites, but with two exceptions had δ 15 N above 10 per mille , reflecting a significant component of heavy anthropogenic N. This variation was not correlated with a north-south gradient. Both Ulva and Gracilaria cultured in water from across Narragansett Bay also had high signals (δ 15 N = ∼14-17 per mille and 8-12 per mille , respectively). These results indicate that inputs of anthropogenic N can have far-reaching impacts throughout estuaries

Natural and anthropogenic nitrogen uptake by bloom-forming macroalgae

Energy Technology Data Exchange (ETDEWEB)

Thornber, Carol S. [Department of Biological Sciences, 100 Flagg Road, University of Rhode Island, Kingston, RI 02881 (United States)], E-mail: thornber@uri.edu; DiMilla, Peter; Nixon, Scott W. [Graduate School of Oceanography, University of Rhode Island, South Ferry Road, Narragansett, RI 02881 (United States); McKinney, Richard A. [US Environmental Protection Agency, Atlantic Ecology Division, 27 Tarzwell Drive, Narragansett, RI 02882 (United States)

2008-02-15

The frequency and duration of macroalgal blooms have increased in many coastal waters over the past several decades. We used field surveys and laboratory culturing experiments to examine the nitrogen content and {delta}{sup 15}N values of Ulva and Gracilaria, two bloom-forming algal genera in Narragansett Bay, RI (USA). The northern end of this bay is densely populated with large sewage treatment plant nitrogen inputs; the southern end is more lightly populated and opens to the Atlantic Ocean. Field-collected Ulva varied in {delta}{sup 15}N among sites, but with two exceptions had {delta}{sup 15}N above 10 per mille , reflecting a significant component of heavy anthropogenic N. This variation was not correlated with a north-south gradient. Both Ulva and Gracilaria cultured in water from across Narragansett Bay also had high signals ({delta}{sup 15}N = {approx}14-17 per mille and 8-12 per mille , respectively). These results indicate that inputs of anthropogenic N can have far-reaching impacts throughout estuaries.

Natural and anthropogenic nitrogen uptake by bloom-forming macroalgae.

Science.gov (United States)

Thornber, Carol S; DiMilla, Peter; Nixon, Scott W; McKinney, Richard A

2008-02-01

The frequency and duration of macroalgal blooms have increased in many coastal waters over the past several decades. We used field surveys and laboratory culturing experiments to examine the nitrogen content and delta(15)N values of Ulva and Gracilaria, two bloom-forming algal genera in Narragansett Bay, RI (USA). The northern end of this bay is densely populated with large sewage treatment plant nitrogen inputs; the southern end is more lightly populated and opens to the Atlantic Ocean. Field-collected Ulva varied in delta(15)N among sites, but with two exceptions had delta(15)N above 10 per thousand, reflecting a significant component of heavy anthropogenic N. This variation was not correlated with a north-south gradient. Both Ulva and Gracilaria cultured in water from across Narragansett Bay also had high signals (delta(15)N= approximately 14-17 per thousand and 8-12 per thousand, respectively). These results indicate that inputs of anthropogenic N can have far-reaching impacts throughout estuaries.

Allelopathic and Bloom-Forming Picocyanobacteria in a Changing World

Directory of Open Access Journals (Sweden)

Sylwia Śliwińska-Wilczewska

2018-01-01

Full Text Available Picocyanobacteria are extremely important organisms in the world’s oceans and freshwater ecosystems. They play an essential role in primary production and their domination in phytoplankton biomass is common in both oligotrophic and eutrophic waters. Their role is expected to become even more relevant with the effect of climate change. However, this group of photoautotrophic organisms still remains insufficiently recognized. Only a few works have focused in detail on the occurrence of massive blooms of picocyanobacteria, their toxicity and allelopathic activity. Filling the gap in our knowledge about the mechanisms involved in the proliferation of these organisms could provide a better understanding of aquatic environments. In this review, we gathered and described recent information about allelopathic activity of picocyanobacteria and occurrence of their massive blooms in many aquatic ecosystems. We also examined the relationships between climate change and representative picocyanobacterial genera from freshwater, brackish and marine ecosystems. This work emphasizes the importance of studying the smallest picoplanktonic fractions of cyanobacteria.

Experience during the monitoring of inactive scrap for the detection of inadvertent presence of radioactivity

International Nuclear Information System (INIS)

Sharma, Ranjit; Anoj Kumar; Vikas; Singh, Rajvir; Patra, R.P.; Vikas Kumar; Pradeepkumar, K.S.

2012-01-01

The paper describes about the experience gained during the radiation monitoring of inactive scrap generated at various nuclear facilities. This type surveillance is carried out to prevent the spread of radioactivity in public domain and also as requirement by regulatory authorities. The inspection and certification of scrap material from nuclear facilities is a regulatory requirement to ensure that no radioactive material reaches public domain. This paper describes the methodology and experience in detection of radioactivity at inactive Scrap monitoring facility. Inactive scraps (metallic and non metallic) generated from various nuclear facilities of BARC, Trombay is dispatched to Trombay Village Store (TVS) for temporary storage before auction to the public. The monitoring at the facility includes visual inspection and radiation measurement before loading the scrap in the truck. An online PC based monitoring system and portable monitoring instruments in the range (nSv/h-µSv/h) are used to carry out radiation monitoring of inactive scrap loaded in a vehicle. Radioactive source of high activity with potential for serious environmental hazard has not been detected, but few cases of presence of radioactive/contaminated material (MS plate/equipments with low level of 137 Cs contamination) have been detected and identified using portable gamma spectrometer. Implementation of strict regulatory measures and radiation monitoring at nuclear facilities can minimize the probability of radioactive material reaching the public domain. The methodology followed for monitoring of inactive scrap is found to be effective even for detection of presence of radioactivity in scrap if any. (author)

MF/UF rejection and fouling potential of algal organic matter from bloom-forming marine and freshwater algae

KAUST Repository

Villacorte, Loreen O.

2015-07-01

Pretreatment with microfiltration (MF) or ultrafiltration (UF) membranes has been proposed for seawater reverse osmosis (SWRO) plants to address operational issues associated with algal blooms. Here, we investigated the MF/UF rejection and fouling potential of algal organic matter (AOM) released by common species of bloom-forming marine (Alexandrium tamarense and Chaetoceros affinis) and freshwater (Microcystis sp.) algae. Batch culture monitoring of the three algal species illustrated varying growth pattern, cell concentration, AOM released and membrane fouling potential. The high membrane fouling potential of the cultures can be directly associated (R2>0.85) with AOM such as transparent exopolymer particle (TEP) while no apparent relationship with algal cell concentration was observed. The AOM comprised mainly biopolymers (e.g., polysaccharides and proteins) and low molecular weight organic compounds (e.g., humic-like substances). The former were largely rejected by MF/UF membranes while the latter were poorly rejected. MF (0.4μm and 0.1μm pore size) rejected 14%-56% of biopolymers while conventional UF (100kDa) and tight UF (10kDa) rejected up to 83% and 97%, respectively. The retention of AOM resulted in a rapid increase in trans-membrane pressure (δP) over time, characterised by pore blocking followed by cake filtration with enhanced compression as illustrated by an exponential progression of δP. © 2015 Elsevier B.V.

Life-history stages of the jellyfish Aurelia aurita - towards a demographic understanding of jellyfish blooms

DEFF Research Database (Denmark)

Goldstein, Josephine

2017-01-01

Jellyfish blooms are conspicuous demographic events that have received increasing attention by the public and the scientific community over the last decades due to their negative impact on fisheries, tourism and other human industries. Several aspects of the complex life cycles of the jellyfish......, including frequent mass occurrence of A. aurita medusae in temperate Danish waters. The present novel data show for instance, that jellyfish blooms of A. aurita are strongly affected by food availability and corresponding shifts between asexually reproducing benthic polyps and sexually reproducing pelagic...... medusae, which might be highly representative for the majority of bloom-forming jellyfish species. Findings further indicate that seasonal shrinkage and subsequent disappearance of A. aurita medusae is rather driven by food limitation than by a trade-off between sexual reproduction and metabolic...

Gulf of Maine Harmful Algal Bloom in summer 2005 - Part 1: In Situ Observations of Coastal Hydrography and Circulation

OpenAIRE

He, Ruoying; McGillicuddy, Dennis J.

2008-01-01

An extensive Alexandrium fundyense bloom occurred along the coast of the Gulf of Maine in late spring and early summer, 2005. To understand the physical aspects of bloom?s initiation and development, in-situ observations from both a gulf-wide ship survey and the coastal observing network were used to characterize coastal circulation and hydrography during that time period. Comparisons between these in-situ observations and their respective long term means revealed anomalous ocean conditions d...

Blooms of phytoplankton along the west coast of India associated with nutrient enrichment and the response of zooplankton

Digital Repository Service at National Institute of Oceanography (India)

Nair, S.R.S.; Devassy, V.P.; Madhupratap, M.

and dinoflagellates are also common Spectacular bloom formations of Trichodesmium is a regular phenomenon during the later part of the NE monsoon season At times, these blooms cover hundreds of kilometres Very often successions of phyto- and zooplankton communities...

Reliable fault detection and diagnosis of photovoltaic systems based on statistical monitoring approaches

KAUST Repository

Harrou, Fouzi

2017-09-18

This study reports the development of an innovative fault detection and diagnosis scheme to monitor the direct current (DC) side of photovoltaic (PV) systems. Towards this end, we propose a statistical approach that exploits the advantages of one-diode model and those of the univariate and multivariate exponentially weighted moving average (EWMA) charts to better detect faults. Specifically, we generate array\\'s residuals of current, voltage and power using measured temperature and irradiance. These residuals capture the difference between the measurements and the predictions MPP for the current, voltage and power from the one-diode model, and use them as fault indicators. Then, we apply the multivariate EWMA (MEWMA) monitoring chart to the residuals to detect faults. However, a MEWMA scheme cannot identify the type of fault. Once a fault is detected in MEWMA chart, the univariate EWMA chart based on current and voltage indicators is used to identify the type of fault (e.g., short-circuit, open-circuit and shading faults). We applied this strategy to real data from the grid-connected PV system installed at the Renewable Energy Development Center, Algeria. Results show the capacity of the proposed strategy to monitors the DC side of PV systems and detects partial shading.

Developing Learning Objectives for Accounting Ethics Using Bloom's Taxonomy

Science.gov (United States)

Kidwell, Linda A.; Fisher, Dann G.; Braun, Robert L.; Swanson, Diane L.

2013-01-01

The purpose of our article is to offer a set of core knowledge learning objectives for accounting ethics education. Using Bloom's taxonomy of educational objectives, we develop learning objectives in six content areas: codes of ethical conduct, corporate governance, the accounting profession, moral development, classical ethics theories, and…

Detection of Atmospheric Explosions at IMS Monitoring Stations using Infrasound Techniques

National Research Council Canada - National Science Library

Christie, Douglas R; Kennett, Brian L; Tarlowski, Chris

2006-01-01

Work is continuing on the development of infrasound techniques that can be used to improve detection, location and discrimination capability for atmospheric nuclear explosions at International Monitoring System (IMS...

Study of ecological consequence of the bloom (Noctiluca miliaris) in off shore waters of the Northern Arabian Sea

Digital Repository Service at National Institute of Oceanography (India)

Dwivedi, R.M.; Chauhan, R.; Solanki, H.U.; Raman, M.; Matondkar, S.G.P.; Madhu, V.R.; Meenakumari, B.

, NO. 4, AUGUST 2012 306 Schools of flying fishes and large size squids were observed during night at one bloom station in March 2007 (FORV-253). Also, on one occasion baby sharks were found swimming inside the bloom patch. These observations...

Rapid bacterial mineralization of organic carbon produced during a phytoplankton bloom induced by natural iron fertilization in the Southern Ocean

Science.gov (United States)

Obernosterer, Ingrid; Christaki, Urania; Lefèvre, Dominique; Catala, Philippe; Van Wambeke, France; Lebaron, Philippe

2008-03-01

The response of heterotrophic bacteria ( Bacteria and Archaea) to the spring phytoplankton bloom that occurs annually above the Kerguelen Plateau (Southern Ocean) due to natural iron fertilization was investigated during the KErguelen Ocean and Plateau compared Study (KEOPS) cruise in January-February 2005. In surface waters (upper 100 m) in the core of the phytoplankton bloom, heterotrophic bacteria were, on an average, 3-fold more abundant and revealed rates of production ([ 3H] leucine incorporation) and respiration (bacterial metabolic activities were attributable to high-nucleic-acid-containing cells that dominated (≈80% of total cell abundance) the heterotrophic bacterial community associated with the phytoplankton bloom. Bacterial growth efficiencies varied between 14% and 20% inside the bloom and were bacterial activity, due to the stimulation by phytoplankton-derived dissolved organic matter. Within the Kerguelen bloom, bacterial carbon demand accounted for roughly 45% of gross community production. These results indicate that heterotrophic bacteria processed a significant portion of primary production, with most of it being rapidly respired.

Monitoring a robot swarm using a data-driven fault detection approach

KAUST Repository

Khaldi, Belkacem

2017-06-30

Using swarm robotics system, with one or more faulty robots, to accomplish specific tasks may lead to degradation in performances complying with the target requirements. In such circumstances, robot swarms require continuous monitoring to detect abnormal events and to sustain normal operations. In this paper, an innovative exogenous fault detection method for monitoring robots swarm is presented. The method merges the flexibility of principal component analysis (PCA) models and the greater sensitivity of the exponentially-weighted moving average (EWMA) and cumulative sum (CUSUM) control charts to insidious changes. The method is tested and evaluated on a swarm of simulated foot-bot robots performing a circle formation task, via the viscoelastic control model. We illustrate through simulated data collected from the ARGoS simulator that a significant improvement in fault detection can be obtained by using the proposed method where compared to the conventional PCA-based methods (i.e., T2 and Q).

Is reduced benthic flux related to the Diporeia decline? Analysis of spring blooms and whiting events in Lake Ontario

Science.gov (United States)

Watkins, James M.; Rudstam, Lars G.; Crabtree, Darran L.; Walsh, Maureen

2013-01-01

Benthic monitoring by USGS off the southern shore of Lake Ontario from October 1993 to October 1995 provides a detailed view of the early stages of the decline of the native amphipod Diporeia. A loss of the 1994 and 1995 year classes of Diporeia preceded the disappearance of the native amphipod at sites near Oswego and Rochester at depths from 55 to 130 m. In succeeding years, Diporeia populations continued to decline in Lake Ontario and were nearly extirpated by 2008. Explanations for Diporeia 's decline in the Great Lakes include several hypotheses often linked to the introduction and expansion of exotic zebra and quagga mussels (Dreissena sp.). We compare the timeline of the Diporeia decline in Lake Ontario with trends in two sources of organic matter to the sediments — spring diatom blooms and late summer whiting events. The 1994–95 decline of Diporeia coincided with localized dreissenid effects on phytoplankton in the nearshore and a year (April 1994 to May 1995) of decreased flux of organic carbon recorded by sediment traps moored offshore of Oswego. Later declines of profundal (> 90 m) Diporeia populations in 2003 were poorly associated with trends in spring algal blooms and late summer whiting events. Lake Ontario/Diporeia/Dreissena/remote sensing.

On the Beat Detection Performance in Long-Term ECG Monitoring Scenarios

Directory of Open Access Journals (Sweden)

Francisco-Manuel Melgarejo-Meseguer

2018-05-01

Full Text Available Despite the wide literature on R-wave detection algorithms for ECG Holter recordings, the long-term monitoring applications are bringing new requirements, and it is not clear that the existing methods can be straightforwardly used in those scenarios. Our aim in this work was twofold: First, we scrutinized the scope and limitations of existing methods for Holter monitoring when moving to long-term monitoring; Second, we proposed and benchmarked a beat detection method with adequate accuracy and usefulness in long-term scenarios. A longitudinal study was made with the most widely used waveform analysis algorithms, which allowed us to tune the free parameters of the required blocks, and a transversal study analyzed how these parameters change when moving to different databases. With all the above, the extension to long-term monitoring in a database of 7-day Holter monitoring was proposed and analyzed, by using an optimized simultaneous-multilead processing. We considered both own and public databases. In this new scenario, the noise-avoid mechanisms are more important due to the amount of noise that exists in these recordings, moreover, the computational efficiency is a key parameter in order to export the algorithm to the clinical practice. The method based on a Polling function outperformed the others in terms of accuracy and computational efficiency, yielding 99.48% sensitivity, 99.54% specificity, 99.69% positive predictive value, 99.46% accuracy, and 0.85% error for MIT-BIH arrhythmia database. We conclude that the method can be used in long-term Holter monitoring systems.

Technology and Bloom's Taxonomy: Tools to Facilitate Higher-Level Learning in Chemistry

National Research Council Canada - National Science Library

Morgan, Matthew

1997-01-01

This research project ties together chemistry data acquisition technology, introductory chemistry laboratory experiments, and Bloom's Taxonomy of Educational Objectives into a unified learning model...

Oil Spills and Dispersants Can Cause the Initiation of Potentially Harmful Dinoflagellate Blooms ("Red Tides").

Science.gov (United States)

Almeda, Rodrigo; Cosgrove, Sarah; Buskey, Edward J

2018-04-25

After oil spills and dispersant applications the formation of red tides or harmful algal blooms (HABs) has been observed, which can cause additional negative impacts in areas affected by oil spills. However, the link between oil spills and HABs is still unknown. Here, we present experimental evidence that demonstrates a connection between oil spills and HABs. We determined the effects of oil, dispersant-treated oil, and dispersant alone on the structure of natural plankton assemblages in the Northern Gulf of Mexico. In coastal waters, large tintinnids and oligotrich ciliates, major grazers of phytoplankton, were negatively affected by the exposure to oil and dispersant, whereas bloom-forming dinoflagellates ( Prorocentrum texanum, P. triestinum, and Scrippsiella trochoidea) notably increased their concentration. The removal of key grazers due to oil and dispersant disrupts the predator-prey controls ("top-down controls") that normally function in plankton food webs. This disruption of grazing pressure opens a "loophole" that allows certain dinoflagellates with higher tolerance to oil and dispersants than their grazers to grow and form blooms when there are no growth limiting factors (e.g., nutrients). Therefore, oil spills and dispersants can act as disrupters of predator-prey controls in plankton food webs and as indirect inducers of potentially harmful dinoflagellate blooms.

ANALISIS SOAL JENJANG KOGNITIF TAKSONOMI BLOOM REVISI PADA BUKU SEKOLAH ELEKTRONIK (BSE BIOLOGI SMA

Directory of Open Access Journals (Sweden)

Aa Juhanda

2016-11-01

Penelitian ini bertujuan untuk menganalisis kemunculan soal jenjang kognitif Bloom Revisi pada Buku Sekolah Elektronik (BSE Biologi SMA. Subjek penelitian adalah 1.650 soal yang terdapat pada BSE Edisi 2009. Instrumen yang digunakan adalah lembar analisis dokumen yang di dalamnya memuat informasi seperti kode soal, soal, dan jenis tingkatan kognitif taksonomi Bloom Revisi. Analisis data dilakukan secara kuantitatif dan kualitatif. Hasil penelitian menunjukkan bahwa rerata persentase kemunculan cukup tinggi diperoleh pada soal yang mengembangkan keterampilan berpikir tingkat rendah (Lower-Order Thinking Skills yaitu soal C1 (mengingat sebesar 46,60% dan C2 (memahami sebesar 47,99%, meskipun untuk C3 (menerapkan persentasenya masih rendah (0,28%. Rerata persentase kemunculan soal yang mengembangkan keterampilan tingkat tinggi (Higher-Order Thinking Skills mulai dari soal C4 (menganalisis sampai dengan C6 (mencipta memiliki rerata persentase yang rendah. Oleh karena itu, kemunculan soal jenjang kognitif Bloom Revisi pada BSE khususnya yang mengembangkan Higher-Order Thinking Skills masih perlu untuk ditingkatkan.

Fault and meal detection by redundant continuous glucose monitors and the unscented Kalman filter

DEFF Research Database (Denmark)

Mahmoudi, Zeinab; Nørgaard, Kirsten; Poulsen, Niels Kjølstad

2017-01-01

The purpose of this study is to develop a method for detecting and compensating the anomalies of continuous glucose monitoring (CGM) sensors as well as detecting unannounced meals. Both features, sensor fault detection/correction and meal detection, are necessary to have a reliable artificial pan...... is corrupted by PISA. The fault isolator can detect 199 out of 200 unannounced meals. The average change in the glucose concentrations between the meals and the detection time points is 46.3 mg/dL.......The purpose of this study is to develop a method for detecting and compensating the anomalies of continuous glucose monitoring (CGM) sensors as well as detecting unannounced meals. Both features, sensor fault detection/correction and meal detection, are necessary to have a reliable artificial...... from the two fault detectors differentiates between a sensor fault and an unannounced meal appearing as an anomaly in the CGM data. If the fault isolator indicates a sensor fault, a method based on the covariance matching technique tunes the covariance of the measurement noise associated...

Exploiting Novel Radiation-Induced Electromagnetic Material Changes for Remote Detection and Monitoring: Final Progress Report

Science.gov (United States)

2016-04-01

Exploiting Novel Radiation -Induced Electromagnetic Material Changes for Remote Detection and Monitoring: Final Progress Report Distribution...assess the effects of ionizing radiation on at least three classes of electromagnetic materials. The proposed approach for radiation detection was...that was desired to be monitored remotely. Microwave or low millimeter wave electromagnetic radiation would be used to interrogate the device

The correlation between Prorocentrum donghaiense blooms and the Taiwan warm current in the East China Sea - evidence for the "Pelagic Seed Bank" hypothesis.

Science.gov (United States)

Dai, Xinfeng; Lu, Douding; Guan, Weibing; Xia, Ping; Wang, Hongxia; He, Piaoxia; Zhang, Dongsheng

2013-01-01

During the last two decades, large-scale high biomass algal blooms of the dinoflagellate Prorocentrum donghaiense Lu have occurred frequently in the East China Sea (ECS). The role of increasing nutrient concentrations in driving those blooms is well-established, but the source population that initiates them is poorly understood. We hypothesized that the front of Taiwan Warm Current (TWC) may serve as a 'seed bank' that initiates P. donghaiense blooms in the ECS, as the physiochemical conditions in the TWC are suitable for the growth of P. donghaiense. In order to test this hypothesis, two surveys at different spatio-temporal scales were conducted in 2010 and 2011. We found a strong correlation in space and time between the abundance of P. donghaiense and the TWC. The spatial extent of the P. donghaiense bloom coincided with the TWC front in both 2010 and 2011. During the early development of the blooms, P. donghaiense concentration was highest at the TWC front, and then the bloom mass shifted inshore over the course of our 2011 survey. The TWC also moved inshore, albeit after the appearance of P. donghaiense. Overall, these results support our hypothesis that P. donghaiense blooms develop from the population at the TWC front in the ECS, suggesting the role of the ocean current front as a seed bank to dinoflagellate blooms.

The correlation between Prorocentrum donghaiense blooms and the Taiwan warm current in the East China Sea - evidence for the "Pelagic Seed Bank" hypothesis.

Directory of Open Access Journals (Sweden)

Xinfeng Dai

Full Text Available During the last two decades, large-scale high biomass algal blooms of the dinoflagellate Prorocentrum donghaiense Lu have occurred frequently in the East China Sea (ECS. The role of increasing nutrient concentrations in driving those blooms is well-established, but the source population that initiates them is poorly understood. We hypothesized that the front of Taiwan Warm Current (TWC may serve as a 'seed bank' that initiates P. donghaiense blooms in the ECS, as the physiochemical conditions in the TWC are suitable for the growth of P. donghaiense. In order to test this hypothesis, two surveys at different spatio-temporal scales were conducted in 2010 and 2011. We found a strong correlation in space and time between the abundance of P. donghaiense and the TWC. The spatial extent of the P. donghaiense bloom coincided with the TWC front in both 2010 and 2011. During the early development of the blooms, P. donghaiense concentration was highest at the TWC front, and then the bloom mass shifted inshore over the course of our 2011 survey. The TWC also moved inshore, albeit after the appearance of P. donghaiense. Overall, these results support our hypothesis that P. donghaiense blooms develop from the population at the TWC front in the ECS, suggesting the role of the ocean current front as a seed bank to dinoflagellate blooms.

Orbitally-forced Azolla blooms and middle Eocene Arctic hydrology; clues from palynology

Science.gov (United States)

Barke, Judith; Abels, Hemmo A.; Sangiorgi, Francesca; Greenwood, David R.; Sweet, Arthur R.; Donders, Timme; Lotter, Andre F.; Reichart, Gert-Jan; Brinkhuis, Henk

2010-05-01

The presence of high abundances of the freshwater fern Azolla in the early Middle Eocene central Arctic Ocean sediments recovered from the Lomonosov Ridge during IODP Expedition 302, have been related to the presence of a substantial freshwater cap. Azolla massulae, belonging to the newly described Eocene species Azolla arctica Collinson et al., have been found over at least a ~4 m-thick interval. There are strong indications that Azolla has bloomed and reproduced in situ in the Arctic Ocean for several hundreds of thousands of years. Possible causes for the sudden demise of Azolla at ~48.1 Ma include salinity changes due to evolving oceanic connections or sea-level change. Distinct cyclic fluctuation in the Azolla massulae abundances have previously been related to orbitally forced climate changes. In this study, we evaluate the possible underlying forcing mechanisms for these freshwater cycles and for the eventual demise of Azolla in an integrated palynological and cyclostratigraphical approach. Our results show two clear periodicities of ~1.3 and ~0.7 m in all major aquatic and terrestrial palynomorph associations, which we can relate to obliquity (41 ka) and precession (~21 ka), respectively. Cycles in the abundances of Azolla, freshwater-tolerant dinoflagellate cysts, and swamp vegetation pollen show co-variability in the obliquity domain. Their strong correlation suggests periods of enhanced rainfall and runoff during Azolla blooms, possibly associated with increased summer season length and insolation during obliquity maxima. Cycles in the angiosperm pollen record are in anti-phase with the Azolla cycles. We interpret this pattern as edaphically drier conditions on land and reduced associated runoff during Azolla lows, possibly corresponding to obliquity minima. The precession signal is distinctly weaker than that for obliquity, and is mainly detectable in the cold-temperate Larix and bisaccate conifer pollen abundances, which is interpreted as a response to

Functions and requirements for Hanford single-shell tank leakage detection and monitoring

International Nuclear Information System (INIS)

Cruse, J.M.; Ohl, P.C.

1995-01-01

This document provides the initial functions and requirements for leakage detection and monitoring applicable to past and potential future leakage from the Hanford Site's 149 single-shell high-level waste tanks. This mission is a part of the overall mission of the Westinghouse Hanford Company Tank Waste Remediation System division to remediate the tank waste in a safe and acceptable manner. Systems engineering principles are being applied to this effort. This document reflects the an initial step in the systems engineering approach to decompose the mission into primary functions and requirements. The document is considered approximately 30% complete relative to the effort required to produce a final version that can be used to support demonstration and/or procurement of technologies. The functions and requirements in this document apply to detection and monitoring of below ground leaks from SST containment boundaries and the resulting soil contamination. Leakage detection and monitoring is invoked in the TWRS Program in three fourth level functions: (1) Store Waste, (2) Retrieve Waste, and (3) Disposition Excess Facilities (as identified in DOE/RL-92-60 Rev. 1, Tank Waste Remediation System Functions and Requirements)

A peptidomic approach for monitoring and characterising peptide cyanotoxins produced in Italian lakes by matrix-assisted laser desorption/ionisation and quadrupole time-of-flight mass spectrometry.

Science.gov (United States)

Ferranti, Pasquale; Nasi, Antonella; Bruno, Milena; Basile, Adriana; Serpe, Luigi; Gallo, Pasquale

2011-05-15

In recent years, the occurrence of cyanobacterial blooms in eutrophic freshwaters has been described all over the world, including most European countries. Blooms of cyanobacteria may produce mixtures of toxic secondary metabolites, called cyanotoxins. Among these, the most studied are microcystins, a group of cyclic heptapeptides, because of their potent hepatotoxicity and activity as tumour promoters. Other peptide cyanotoxins have been described whose structure and toxicity have not been thoroughly studied. Herein we present a peptidomic approach aimed to characterise and quantify the peptide cyanotoxins produced in two Italian lakes, Averno and Albano. The procedure was based on matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry mass spectrometry (MALDI-TOF-MS) analysis for rapid detection and profiling of the peptide mixture complexity, combined with liquid chromatography/electrospray ionisation quadrupole time-of- flight tandem mass spectrometry (LC/ESI-Q-TOF-MS/MS) which provided unambiguous structural identification of the main compounds, as well as accurate quantitative analysis of microcystins. In the case of Lake Averno, a novel variant of microcystin-RR and two novel anabaenopeptin variants (Anabaenopeptins B(1) and Anabaenopeptin F(1)), presenting homoarginine in place of the commonly found arginine, were detected and characterised. In Lake Albano, the peculiar peptide patterns in different years were compared, as an example of the potentiality of the peptidomic approach for fast screening analysis, prior to fine structural analysis and determination of cyanotoxins, which included six novel aeruginosin variants. This approach allows for wide range monitoring of cyanobacteria blooms, and to collect data for evaluating possible health risks to consumers, through the panel of the compounds produced along different years. Copyright © 2011 John Wiley & Sons, Ltd.

Continuous Blood Glucose Monitoring May Detect Carotid Occlusion Intolerance during Carotid Artery Stenting.

Science.gov (United States)

Hiramatsu, Ryo; Furuse, Motomasa; Yagi, Ryokichi; Ohmura, Tomohisa; Ohnishi, Hiroyuki; Ikeda, Naokado; Nonoguchi, Naosuke; Kawabata, Shinji; Miyachi, Shigeru; Kuroiwa, Toshihiko

2018-02-05

The frequency of the occurrence of adverse events associated with carotid artery stenting (CAS) is usually low, but serious adverse events such as cerebral hyperperfusion syndrome (CHS) may occur. Real-time monitoring is ideal for the early detection of adverse events during the surgical procedure. This study aimed to evaluate continuous blood glucose (BG) monitoring for the detection of adverse events during CAS. Forty patients undergoing scheduled CAS were prospectively enrolled. An artificial pancreas was used for continuous BG monitoring (once per minute), using venous blood extracted at a rate of 2 mL/hr during CAS. The primary endpoint was a correlation between BG change and adverse events. CAS was discontinued in 1 patient, and BG was not measured in 5 patients (12.5%) because of the inability to extract blood. Among 34 evaluable patients, no patient developed CHS, but 3 patients (9%) experienced carotid occlusion intolerance. During CAS, BG was significantly higher in patients with carotid occlusion intolerance (median: 5 mg/dL) than in patients without carotid occlusion intolerance (median: 0 mg/dL) (P = 0.0221). A cutoff BG value ≥4 mg/dL during CAS showed 50% sensitivity and 100% specificity for the detection of carotid occlusion intolerance. There was no significant correlation between BG change and other adverse events. BG elevation may help detect carotid occlusion intolerance although it is still unknown whether BG monitoring can detect CHS. Further studies should validate that a cutoff BG elevation value of ≥4 mg/dL during CAS indicates carotid occlusion intolerance. Copyright © 2018 Elsevier Inc. All rights reserved.

Analysis of algae growth mechanism and water bloom prediction under the effect of multi-affecting factor.

Science.gov (United States)

Wang, Li; Wang, Xiaoyi; Jin, Xuebo; Xu, Jiping; Zhang, Huiyan; Yu, Jiabin; Sun, Qian; Gao, Chong; Wang, Lingbin

2017-03-01

The formation process of algae is described inaccurately and water blooms are predicted with a low precision by current methods. In this paper, chemical mechanism of algae growth is analyzed, and a correlation analysis of chlorophyll-a and algal density is conducted by chemical measurement. Taking into account the influence of multi-factors on algae growth and water blooms, the comprehensive prediction method combined with multivariate time series and intelligent model is put forward in this paper. Firstly, through the process of photosynthesis, the main factors that affect the reproduction of the algae are analyzed. A compensation prediction method of multivariate time series analysis based on neural network and Support Vector Machine has been put forward which is combined with Kernel Principal Component Analysis to deal with dimension reduction of the influence factors of blooms. Then, Genetic Algorithm is applied to improve the generalization ability of the BP network and Least Squares Support Vector Machine. Experimental results show that this method could better compensate the prediction model of multivariate time series analysis which is an effective way to improve the description accuracy of algae growth and prediction precision of water blooms.

Random Access for Machine-Type Communication based on Bloom Filtering

DEFF Research Database (Denmark)

Pratas, Nuno; Stefanovic, Cedomir; Madueño, Germán Corrales

2016-01-01

utilizes the system resources more efficiently and achieves similar or lower latency of connection establishment in case of synchronous arrivals, compared to the variant of the LTE-A access protocol that is optimized for MTC traffic. A dividend of the proposed method is that allows the base station (BS......We present a random access method inspired on Bloom filters that is suited for Machine-Type Communications (MTC). Each accessing device sends a signature during the contention process. A signature is constructed using the Bloom filtering method and contains information on the device identity...... and the connection establishment cause. We instantiate the proposed method over the current LTE-A access protocol. However, the method is applicable to a more general class of random access protocols that use preambles or other reservation sequences, as expected to be the case in 5G systems. We show that our method...

Genome-derived insights into the biology of the hepatotoxic bloom-forming cyanobacterium Anabaena sp. strain 90

Directory of Open Access Journals (Sweden)

Wang Hao

2012-11-01

Full Text Available Abstract Background Cyanobacteria can form massive toxic blooms in fresh and brackish bodies of water and are frequently responsible for the poisoning of animals and pose a health risk for humans. Anabaena is a genus of filamentous diazotrophic cyanobacteria commonly implicated as a toxin producer in blooms in aquatic ecosystems throughout the world. The biology of bloom-forming cyanobacteria is poorly understood at the genome level. Results Here, we report the complete sequence and comprehensive annotation of the bloom-forming Anabaena sp. strain 90 genome. It comprises two circular chromosomes and three plasmids with a total size of 5.3 Mb, encoding a total of 4,738 genes. The genome is replete with mobile genetic elements. Detailed manual annotation demonstrated that almost 5% of the gene repertoire consists of pseudogenes. A further 5% of the genome is dedicated to the synthesis of small peptides that are the products of both ribosomal and nonribosomal biosynthetic pathways. Inactivation of the hassallidin (an antifungal cyclic peptide biosynthetic gene cluster through a deletion event and a natural mutation of the buoyancy-permitting gvpG gas vesicle gene were documented. The genome contains a large number of genes encoding restriction-modification systems. Two novel excision elements were found in the nifH gene that is required for nitrogen fixation. Conclusions Genome analysis demonstrated that this strain invests heavily in the production of bioactive compounds and restriction-modification systems. This well-annotated genome provides a platform for future studies on the ecology and biology of these important bloom-forming cyanobacteria.

Biofouling in capillary and spiral wound membranes facilitated by marine algal bloom

DEFF Research Database (Denmark)

Villacorte, L.O.; Ekowati, Y.; Calix-Ponce, H.N.

2017-01-01

blooms. The tendency of AOM from bloom-forming marine algae to adhere to membranes and its ability to enhance biofilm growth were measured using atomic force microscopy, flow cytometry, liquid chromatography and accelerated membrane biofouling experiments. Adhesion force measurements indicate that AOM......Algal-derived organic matter (AOM), particularly transparent exopolymer particles, has been suspected to facilitate biofilm development in membrane systems (e.g., seawater reverse osmosis). This study demonstrates the possible role of AOM on biofouling in membrane systems affected by marine algal...... biodegradable nutrients. The abovementioned findings indicate that AOM facilitates the onset of membrane biofouling primarily as a conditioning platform and to some extent as a nutrient source for biofilm-forming bacteria....

HARMFUL ALGAL BLOOMS IN THE MEDITERRANEAN SEA: EFFECTS ON HUMAN HEALTH.

Directory of Open Access Journals (Sweden)

Margherita Ferrante

2013-01-01

Full Text Available A harmful algal bloom (HAB is defined as a bloom that has deleterious effects on plants, animals or humans. Marine algal toxins are responsible for an array of human illnesses associated with consumption of seafood or exposure to aerosolized toxins. The effects of algal toxins are generally observed as acute intoxications, whereas the environmental health effects of chronic exposure to low levels of algal toxins are, to date, only poorly documented and an emerging issue. Consumption of seafood contaminated with algal toxins can result in five types of seafood poisoning syndromes: paralytic shellfish poisoning, neurotoxic shellfish poisoning, amnesic shellfish poisoning, diarrhetic shellfish poisoning and ciguatera fish poisoning. The aim of this paper is to provide an overview on HAB-related issues in the Mediterranean Sea.

Seasonal dynamics in dissolved organic matter, hydrogen peroxide, and cyanobacterial blooms in Lake Erie

Directory of Open Access Journals (Sweden)

Rose M. Cory

2016-04-01

Full Text Available Hydrogen peroxide (H2O2 has been suggested to influence cyanobacterial community structure and toxicity. However, no study has investigated H2O2 concentrations in freshwaters relative to cyanobacterial blooms when sources and sinks of H2O2 may be highly variable. For example, photochemical production of H2O2 from chromophoric dissolved organic matter (CDOM may vary over the course of the bloom with changing CDOM and UV light in the water column, while microbial sources and sinks of H2O2 may change with community biomass and composition. To assess relationships between H2O2 and harmful algal blooms dominated by toxic cyanobacteria in the western basin of Lake Erie, we measured H2O2 weekly at six stations from June – November, 2014 and 2015, with supporting physical, chemical, and biological water quality data. Nine additional stations across the western, eastern, and central basins of Lake Erie were sampled during August and October, 2015. CDOM sources were quantified from the fluorescence fraction of CDOM using parallel factor analysis (PARAFAC. CDOM concentration and source were significantly correlated with specific conductivity, demonstrating that discharge of terrestrially-derived CDOM from rivers can be tracked in the lake. Autochthonous sources of CDOM in the lake increased over the course of the blooms. Concentrations of H2O2 in Lake Erie ranged from 47 ± 16 nM to 1570 ± 16 nM (average of 371 ± 17 nM; n = 225, and were not correlated to CDOM concentration or source, UV light, or estimates of photochemical production of H2O2 by CDOM. Temporal patterns in H2O2 were more closely aligned with bloom dynamics in the lake. In 2014 and 2015, maximum concentrations of H2O2 were observed prior to peak water column respiration and chlorophyll a, coinciding with the onset of the widespread Microcystis blooms in late July. The spatial and temporal patterns in H2O2 concentrations suggested that production and decay of H2O2 from aquatic

Use of Portal Monitors for Detection of Technogenic Radioactive Sources in Scrap Metal

Science.gov (United States)

Solovev, D. B.; Merkusheva, A. E.

2017-11-01

The article considers the features of organization of scrap-metal primary radiation control on the specialized enterprises engaging in its deep processing and storage at using by primary technical equipment - radiation portal monitors. The issue of this direction relevance, validity of radiation control implementation with the use of radiation portal monitors, physical and organizational bases of radiation control are considered in detail. The emphasis is put on the considerable increase in the number of technogenic radioactive sources detected in scrap-metal that results in the entering into exploitation of radioactive metallic structures as different building wares. One of reasons of such increase of the number of technogenic radioactive sources getting for processing with scrap-metal is the absence of any recommendations on the radiation portal monitors exploitation. The practical division of the article offers to recommendation on tuning of the modes of work of radiation portal monitors depending on influence the weather factor thus allowing to considerably increase the percent of technogenic radioactive sources detection.

Blooms of a benthic ciliate, Maristentor dinoferus (Heterotrichea: Maristentoridae, on coral reefs of Guam, Mariana Islands. (Note

Directory of Open Access Journals (Sweden)

Schefter, M.

2012-05-01

Full Text Available Maristentor dinoferus is visible in situ with the naked eye; it forms aggregations at several scales: individuals form dynamic clusters within colonies that are normally widely scattered, but in recurrent blooms during the dry seasons of 2005 through 2007, colonies often formed close together in patches (metapopulations. Patches were extremely abundant in Guam, both in Apra Harbor and on the outer coast. This is the first time that long-term changes in a benthic ciliate population have been documented in situ and that multi-scale patchiness has been reported for a benthic ciliate. Colonies were mapped and monitored; some patches over 1 m diameter were recorded. Since 2008, the distribution has again consisted of scattered colonies, as it did from 1999–2004.

Retention time generates short-term phytoplankton blooms in a shallow microtidal subtropical estuary

Science.gov (United States)

Odebrecht, Clarisse; Abreu, Paulo C.; Carstensen, Jacob

2015-09-01

In this study it was hypothesised that increasing water retention time promotes phytoplankton blooms in the shallow microtidal Patos Lagoon estuary (PLE). This hypothesis was tested using salinity variation as a proxy of water retention time and chlorophyll a for phytoplankton biomass. Submersible sensors fixed at 5 m depth near the mouth of PLE continuously measured water temperature, salinity and pigments fluorescence (calibrated to chlorophyll a) between March 2010 and 12th of December 2011, with some gaps. Salinity variations were used to separate alternating patterns of outflow of lagoon water (salinity 24; 35% of the time). The two transition phases represented a rapid change from lagoon water outflow to marine water inflow and a more gradually declining salinity between the dominating inflow and outflow conditions. During the latter of these, a significant chlorophyll a increase relative to that expected from a linear mixing relationship was observed at intermediate salinities (10-20). The increase in chlorophyll a was positively related to the duration of the prior coastal water inflow in the PLE. Moreover, chlorophyll a increase was significantly higher during austral spring-summer than autumn-winter, probably due to higher light and nutrient availability in the former. Moreover, the retention time process operating on time scales of days influences the long-term phytoplankton variability in this ecosystem. Comparing these results with monthly data from a nearby long-term water quality monitoring station (1993-2011) support the hypothesis that chlorophyll a accumulations occur after marine inflow events, whereas phytoplankton does not accumulate during high water outflow, when the water residence time is short. These results suggest that changing hydrological pattern is the most important mechanism underlying phytoplankton blooms in the PLE.

From Rare to Dominant: a Fine-Tuned Soil Bacterial Bloom during Petroleum Hydrocarbon Bioremediation.

Science.gov (United States)

Fuentes, Sebastián; Barra, Bárbara; Caporaso, J Gregory; Seeger, Michael

2016-02-01

Hydrocarbons are worldwide-distributed pollutants that disturb various ecosystems. The aim of this study was to characterize the short-lapse dynamics of soil microbial communities in response to hydrocarbon pollution and different bioremediation treatments. Replicate diesel-spiked soil microcosms were inoculated with either a defined bacterial consortium or a hydrocarbonoclastic bacterial enrichment and incubated for 12 weeks. The microbial community dynamics was followed weekly in microcosms using Illumina 16S rRNA gene sequencing. Both the bacterial consortium and enrichment enhanced hydrocarbon degradation in diesel-polluted soils. A pronounced and rapid bloom of a native gammaproteobacterium was observed in all diesel-polluted soils. A unique operational taxonomic unit (OTU) related to the Alkanindiges genus represented ∼ 0.1% of the sequences in the original community but surprisingly reached >60% after 6 weeks. Despite this Alkanindiges-related bloom, inoculated strains were maintained in the community and may explain the differences in hydrocarbon degradation. This study shows the detailed dynamics of a soil bacterial bloom in response to hydrocarbon pollution, resembling microbial blooms observed in marine environments. Rare community members presumably act as a reservoir of ecological functions in high-diversity environments, such as soils. This rare-to-dominant bacterial shift illustrates the potential role of a rare biosphere facing drastic environmental disturbances. Additionally, it supports the concept of "conditionally rare taxa," in which rareness is a temporary state conditioned by environmental constraints. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Gibberellin Application at Pre-Bloom in Grapevines Down-Regulates the Expressions of VvIAA9 and VvARF7, Negative Regulators of Fruit Set Initiation, during Parthenocarpic Fruit Development

Science.gov (United States)

Jung, Chan Jin; Hur, Youn Young; Yu, Hee-Ju; Noh, Jung-Ho; Park, Kyo-Sun; Lee, Hee Jae

2014-01-01

Fruit set is initiated only after fertilization and is tightly regulated primarily by gibberellins (GAs) and auxins. The application of either of these hormones induces parthenocarpy, fruit set without fertilization, but the molecular mechanism underlying this induction is poorly understood. In the present study, we have shown that the parthenocarpic fruits induced by GA application at pre-bloom result from the interaction of GA with auxin signaling. The transcriptional levels of the putative negative regulators of fruit set initiation, including Vitis auxin/indole-3-acetic acid transcription factor 9 (VvIAA9), Vitis auxin response factor 7 (VvARF7), and VvARF8 were monitored during inflorescence development in seeded diploid ‘Tamnara’ grapevines with or without GA application. Without GA application, VvIAA9, VvARF7, and VvARF8 were expressed at a relatively high level before full bloom, but decreased thereafter following pollination. After GA application at 14 days before full bloom (DBF); however, the expression levels of VvIAA9 and VvARF7 declined at 5 DBF prior to pollination. The effects of GA application on auxin levels or auxin signaling were also analyzed by monitoring the expression patterns of auxin biosynthesis genes and auxin-responsive genes with or without GA application. Transcription levels of the auxin biosynthesis genes Vitis anthranilate synthase β subunit (VvASB1-like), Vitis YUCCA2 (VvYUC2), and VvYUC6 were not significantly changed by GA application. However, the expressions of Vitis Gretchen Hagen3.2 (VvGH3.2) and VvGH3.3, auxin-responsive genes, were up-regulated from 2 DBF to full bloom with GA application. Furthermore, the Vitis GA signaling gene, VvDELLA was up-regulated by GA application during 12 DBF to 7 DBF, prior to down-regulation of VvIAA9 and VvARF7. These results suggest that VvIAA9 and VvARF7 are negative regulators of fruit set initiation in grapevines, and GA signaling is integrated with auxin signaling via VvDELLA during

Design of Wearable Breathing Sound Monitoring System for Real-Time Wheeze Detection

Directory of Open Access Journals (Sweden)

Shih-Hong Li

2017-01-01

Full Text Available In the clinic, the wheezing sound is usually considered as an indicator symptom to reflect the degree of airway obstruction. The auscultation approach is the most common way to diagnose wheezing sounds, but it subjectively depends on the experience of the physician. Several previous studies attempted to extract the features of breathing sounds to detect wheezing sounds automatically. However, there is still a lack of suitable monitoring systems for real-time wheeze detection in daily life. In this study, a wearable and wireless breathing sound monitoring system for real-time wheeze detection was proposed. Moreover, a breathing sounds analysis algorithm was designed to continuously extract and analyze the features of breathing sounds to provide the objectively quantitative information of breathing sounds to professional physicians. Here, normalized spectral integration (NSI was also designed and applied in wheeze detection. The proposed algorithm required only short-term data of breathing sounds and lower computational complexity to perform real-time wheeze detection, and is suitable to be implemented in a commercial portable device, which contains relatively low computing power and memory. From the experimental results, the proposed system could provide good performance on wheeze detection exactly and might be a useful assisting tool for analysis of breathing sounds in clinical diagnosis.

Physical processes contributing to harmful algal blooms in Saldanha ...

African Journals Online (AJOL)

Since 1994, disruption of harvesting as a result of the presence of harmful algal species has been a regular late-summer phenomenon. Toxic blooms that are ultimately advected into the bay develop on the continental shelf to the north between 32°S and St Helena Bay, a region characterized by favourable conditions for ...

Apples, Bloom, and Creativity: The ABC's of Reading Alphabet Books.

Science.gov (United States)

Taylor, Mary Agnes

Benjamin Bloom's taxonomy of educational objectives (knowledge, comprehension, application, analysis, synthesis, and evaluation) combined with commonly accepted steps of the creative process (gathering material, reflection, inspiration, first draft or model, and evaluation) can be used to explore some of the possibilities of working with alphabet…

Dynamics of cyanobacterial bloom formation during short-term hydrodynamic fluctuation in a large shallow, eutrophic, and wind-exposed Lake Taihu, China.

Science.gov (United States)

Wu, Tingfeng; Qin, Boqiang; Zhu, Guangwei; Luo, Liancong; Ding, Yanqing; Bian, Geya

2013-12-01

Short-term hydrodynamic fluctuations caused by extreme weather events are expected to increase worldwide because of global climate change, and such fluctuations can strongly influence cyanobacterial blooms. In this study, the cyanobacterial bloom disappearance and reappearance in Lake Taihu, China, in response to short-term hydrodynamic fluctuations, was investigated by field sampling, long-term ecological records, high-frequency sensors and MODIS satellite images. The horizontal drift caused by the dominant easterly wind during the phytoplankton growth season was mainly responsible for cyanobacterial biomass accumulation in the western and northern regions of the lake and subsequent bloom formation over relatively long time scales. The cyanobacterial bloom changed slowly under calm or gentle wind conditions. In contrast, the short-term bloom events within a day were mainly caused by entrainment and disentrainment of cyanobacterial colonies by wind-induced hydrodynamics. Observation of a westerly event in Lake Taihu revealed that when the 30 min mean wind speed (flow speed) exceeded the threshold value of 6 m/s (5.7 cm/s), cyanobacteria in colonies were entrained by the wind-induced hydrodynamics. Subsequently, the vertical migration of cyanobacterial colonies was controlled by hydrodynamics, resulting in thorough mixing of algal biomass throughout the water depth and the eventual disappearance of surface blooms. Moreover, the intense mixing can also increase the chance for forming larger and more cyanobacterial colonies, namely, aggregation. Subsequently, when the hydrodynamics became weak, the cyanobacterial colonies continuously float upward without effective buoyancy regulation, and cause cyanobacterial bloom explosive expansion after the westerly. Furthermore, the results of this study indicate that the strong wind happening frequently during April and October can be an important cause of the formation and expansion of cyanobacterial blooms in Lake Taihu.

Bacterial and protist community changes during a phytoplankton bloom

KAUST Repository

Pearman, John K.

2015-10-01

The present study aims to characterize the change in the composition and structure of the bacterial and microzooplankton planktonic communities in relation to the phytoplankton community composition during a bloom. High-throughput amplicon sequencing of regions of the 16S and 18S rRNA gene was undertaken on samples collected during a 20 day (d) mesocosm experiment incorporating two different nutrient addition treatments [Nitrate and Phosphate (NPc) and Nitrate, Phosphate and Silicate (NPSc)] as well as a control. This approach allowed us to discriminate the changes in species composition across a broad range of phylogenetic groups using a common taxonomic level. Diatoms dominated the bloom in the NPSc treatment while dinoflagellates were the dominant phytoplankton in the control and NPc treatment. Network correlations highlighted significant interactions between OTUs within each treatment including changes in the composition of Paraphysomonas OTUs when the dominant Chaetoceros OTU switched. The microzooplankton community composition responded to changes in the phytoplankton composition while the prokaryotic community responded more to changes in ammonia concentration.

Radioactive aerosol detection station for near real-time atmospheric monitoring

International Nuclear Information System (INIS)

Mason, L.R.; Bohner, John D.

1997-01-01

A radionuclide aerosol detection station has been developed to measure radioactivity in the environment. The objective is to monitor the atmosphere for anthropogenic radioactivity that could be indicative of nuclear weapons tests to verify the Comprehensive Nuclear Test Ban Treaty. Eighty stations will form the backbone of the International Monitoring System in which stations are linked to a central analysis facility called the International Data Centre. Data are transmitted to this centre in near real-time to facilitate rapid detection. Principal process of the field measurement are collection, separation, and assay. Collection of airborne radioactivity is achieved through high-volume air sampling. Aerosols separation is accomplished by high-efficiency particulate filtration. Radionuclides assay is achieved by in-situ high resolution gamma spectrometry. These modules are integrated into a unit that provides power, control, and communication support subsystems. Station operation is semi-automatic requiring only minimal human interaction. (author). 6 refs., 3 figs., 3 tabs

Applications of polarization speckle in skin cancer detection and monitoring

Science.gov (United States)

Lee, Tim K.; Tchvialeva, Lioudmila; Phillips, Jamie; Louie, Daniel C.; Zhao, Jianhua; Wang, Wei; Lui, Harvey; Kalia, Sunil

2018-01-01

Polarization speckle is a rapidly developed field. Unlike laser speckle, polarization speckle consists of stochastic interference patterns with spatially random polarizations, amplitudes and phases. We have been working in this exciting research field, developing techniques to generate polarization patterns from skin. We hypothesize that polarization speckle patterns could be used in biomedical applications, especially, for detecting and monitoring skin cancers, the most common neoplasmas for white populations around the world. This paper describes our effort in developing two polarization speckle devices. One of them captures the Stokes parameters So and S1 simultaneously, and another one captures all four Stokes parameters So, S1, S2, and S3 in one-shot, within milliseconds. Hence these two devices could be used in medical clinics and assessed skin conditions in-vivo. In order to validate our hypothesis, we conducted a series of three clinical studies. These are early pilot studies, and the results suggest that the devices have potential to detect and monitor skin cancers.

Monitoring a robot swarm using a data-driven fault detection approach

KAUST Repository

Khaldi, Belkacem; Harrou, Fouzi; Cherif, Foudil; Sun, Ying

2017-01-01

Using swarm robotics system, with one or more faulty robots, to accomplish specific tasks may lead to degradation in performances complying with the target requirements. In such circumstances, robot swarms require continuous monitoring to detect

A measurement-based fault detection approach applied to monitor robots swarm

KAUST Repository

Khaldi, Belkacem; Harrou, Fouzi; Sun, Ying; Cherif, Foudil

2017-01-01

present an innovative data-driven fault detection method for monitoring robots swarm. The method combines the flexibility of principal component analysis (PCA) models and the greater sensitivity of the exponentially-weighted moving average control chart

West Coast DA Event data - West Coast Toxic Pseudo-nitzschia bloom

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Beginning in the spring of 2015 the US West Coast began to experience the most wide-spread toxic Pseudo-nitzschia bloom to date, after approximately eight years...

Improved detection of incipient anomalies via multivariate memory monitoring charts: Application to an air flow heating system

KAUST Repository

Harrou, Fouzi