WorldWideScience

Sample records for blooms connecting sources

  1. Connecting Florida Bay algal blooms to freshwater nutrient sources

    Science.gov (United States)

    Blakey, T.; Melesse, A. M.

    2013-12-01

    In this study, monthly water quality data collected in the Everglades by the Southeast Environmental Research Center (SERC) and the South Florida Water Management District (SFWMD) from 1991 to 2008 at 28 sampling stations distributed across Florida Bay was analyzed within the context of local geomorphology and seasonal wind and current regimes in order to evaluate the feasibility of the various purported nutrient sources for reoccurring algal blooms. The in situ chlorophyll-a (chl-a) measurements from the SERC dataset were evaluated as the indicator of algal biomass. Significant differences in average monthly chl-a concentrations at stations indicated a seasonality of algal blooms in the north central and west areas that is not evidenced in stations exhibiting low levels of chl-a throughout the typical year. Tukey's pairwise comparisons of monthly chl-a indicated, at the 95% confidence level, peak algal biomass occurs in October and November at the end of the wet season with minimums occurring between February and August depending on the location of the station. By month comparison of chl-a levels across stations suggest seasonal trends in the geographic focus and extent of blooms. Significant differences from Tukey's pairwise comparisons at the 95% confidence level showed stations to the west as having higher levels of chl-a in March through May with north central stations dominating from June to January. The month of February shows no significant difference in chl-a levels across this area. The results support hypotheses centering on a western source of nutrients that are delivered to the bay over the course of the rainy season. Mapping water quality sampling station locations on top of the bathymetry of Florida Bay illustrates the importance of considering coastal morphology in explaining trends in estuarine algal blooms. Coastal geomorphology along with seasonal changes in the direction of winds and magnitude of rains are demonstrated to be the predominant

  2. A multiprotein nuclear complex connects Fanconi anemia and Bloom syndrome.

    NARCIS (Netherlands)

    Meetei, AR; Sechi, S; Wallisch, M; Yang, D; Young, MK; Joenje, H.; Hoatlin, M.E.

    2003-01-01

    Bloom syndrome (BS) is a genetic disorder associated with dwarfism, immunodeficiency, reduced fertility, and an elevated risk of cancer. To investigate the mechanism of this disease, we isolated from human HeLa extracts three complexes containing the helicase defective in BS, BLM. Interestingly, one

  3. Scaffolding protein SPIDR/KIAA0146 connects the Bloom syndrome helicase with homologous recombination repair.

    Science.gov (United States)

    Wan, Li; Han, Jinhua; Liu, Ting; Dong, Shunli; Xie, Feng; Chen, Hongxia; Huang, Jun

    2013-06-25

    The Bloom syndrome gene product, BLM, is a member of the highly conserved RecQ family. An emerging concept is the BLM helicase collaborates with the homologous recombination (HR) machinery to help avoid undesirable HR events and to achieve a high degree of fidelity during the HR reaction. However, exactly how such coordination occurs in vivo is poorly understood. Here, we identified a protein termed SPIDR (scaffolding protein involved in DNA repair) as the link between BLM and the HR machinery. SPIDR independently interacts with BLM and RAD51 and promotes the formation of a BLM/RAD51-containing complex of biological importance. Consistent with its role as a scaffolding protein for the assembly of BLM and RAD51 foci, cells depleted of SPIDR show increased rate of sister chromatid exchange and defects in HR. Moreover, SPIDR depletion leads to genome instability and causes hypersensitivity to DNA damaging agents. We propose that, through providing a scaffold for the cooperation of BLM and RAD51 in a multifunctional DNA-processing complex, SPIDR not only regulates the efficiency of HR, but also dictates the specific HR pathway.

  4. Defining the molecular interface that connects the Fanconi anemia protein FANCM to the Bloom syndrome dissolvasome.

    Science.gov (United States)

    Hoadley, Kelly A; Xue, Yutong; Ling, Chen; Takata, Minoru; Wang, Weidong; Keck, James L

    2012-03-20

    The RMI subcomplex (RMI1/RMI2) functions with the BLM helicase and topoisomerase IIIα in a complex called the "dissolvasome," which separates double-Holliday junction DNA structures that can arise during DNA repair. This activity suppresses potentially harmful sister chromatid exchange (SCE) events in wild-type cells but not in cells derived from Bloom syndrome patients with inactivating BLM mutations. The RMI subcomplex also associates with FANCM, a component of the Fanconi anemia (FA) core complex that is important for repair of stalled DNA replication forks. The RMI/FANCM interface appears to help coordinate dissolvasome and FA core complex activities, but its precise role remains poorly understood. Here, we define the structure of the RMI/FANCM interface and investigate its roles in coordinating cellular DNA-repair activities. The X-ray crystal structure of the RMI core complex bound to a well-conserved peptide from FANCM shows that FANCM binds to both RMI proteins through a hydrophobic "knobs-into-holes" packing arrangement. The RMI/FANCM interface is shown to be critical for interaction between the components of the dissolvasome and the FA core complex. FANCM variants that substitute alanine for key interface residues strongly destabilize the complex in solution and lead to increased SCE levels in cells that are similar to those observed in blm- or fancm-deficient cells. This study provides a molecular view of the RMI/FANCM complex and highlights a key interface utilized in coordinating the activities of two critical eukaryotic DNA-damage repair machines.

  5. The relative roles of modified circumpolar deep water and benthic sources in supplying iron to the recurrent phytoplankton blooms above Pennell and Mawson Banks, Ross Sea, Antarctica

    Science.gov (United States)

    Hatta, Mariko; Measures, Chris I.; Lam, Phoebe J.; Ohnemus, Daniel C.; Auro, Maureen E.; Grand, Maxime M.; Selph, Karen E.

    2017-02-01

    The role that dissolved iron (dFe) rich Circumpolar Deep Water (CDW) might play in sustaining the consistently observed discrete patches of high chlorophyll biomass over Pennell Bank (PB) and Mawson Bank (MB) in the Ross Sea, was investigated during January/February 2011. Over a 26-day period, hydrographic and trace metal clean water sampling was carried out adjacent to both of these banks, in some cases repeatedly. Particulate sampling was also accomplished at selected stations by in situ pumping. The results indicate that the dFe content of the CDW is in fact reduced by on-shelf mixing with Antarctic Surface Water as it transitions into modified CDW (MCDW). Our stations above PB, where the maximum bloom is encountered, show no evidence of MCDW presence. In contrast, above MB, where there is a smaller persistent bloom, MCDW was observed. Although both of these stations displayed the imprint of sedimentary Fe input connected to the strong tidal cycles above the banks, the stronger near-bottom density gradient that MCDW produces appears to contribute to reduced vertical mixing of the sedimentary source. Thus, ironically, the presence of MCDW may be hindering the Fe supply to the surface waters, rather than being the source, as originally hypothesized.

  6. Genetics Home Reference: Bloom syndrome

    Science.gov (United States)

    ... 1 link) BLOOM SYNDROME Sources for This Page Amor-Guéret M. Bloom syndrome, genomic instability and cancer: ... Zhang B, Zhang XD, Dou SX, Wang PY, Amor-Gueret M, Xi XG. Structural and functional analyses ...

  7. Effects of auxiliary source connections in multichip power module

    DEFF Research Database (Denmark)

    Li, Helong; Munk-Nielsen, Stig; Beczkowski, Szymon

    2016-01-01

    totally decouple the power loop and the gate loop like how the Kelvin source connection does, because they are still in the loop of power source current. Three effects of the auxiliary source connection are investigated and analyzed: common source stray inductance reduction, transient drain-source current......Auxiliary source bond wires and connections are widely used to in the power module with paralleled MOSFETs or IGBTs. This paper investigates the working mechanism and the effects of the auxiliary source connections in multichip power modules. It reveals that the auxiliary source connections cannot...... imbalance mitigation and influence on the steady state bond wire current distribution. Simulation and experimental results validate the working mechanism analysis and the effects of the auxiliary source connections....

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

    Science.gov (United States)

    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...

  9. Effects of Auxiliary-Source Connection in Multichip Power Module

    DEFF Research Database (Denmark)

    Li, Helong; Munk-Nielsen, Stig; Wang, Xiongfei

    2017-01-01

    the power loop and the gate loop like how the Kelvin-source connection does, owing to their involvement in the loop of the power source current. Three effects of the auxiliary-source connections are then analyzed, which are 1) the common source stray inductance reduction, 2) the transient drain......Auxiliary-source bond wires and connections are widely used in power modules with paralleled MOSFETs or IGBTs. This paper investigates the operation mechanism of the auxiliary-source connections in multichip power modules. It reveals that the auxiliary-source connections cannot fully decouple......-source current imbalance mitigation, and 3) the influence on the steady-state current distribution. Lastly, simulations and experimental results validate the theoretical analysis....

  10. SCoT: a Python toolbox for EEG source connectivity

    OpenAIRE

    Billinger, Martin; Brunner, Clemens; Müller-Putz, Gernot R.

    2014-01-01

    Analysis of brain connectivity has become an important research tool in neuroscience. Connectivity can be estimated between cortical sources reconstructed from the electroencephalogram (EEG). Such analysis often relies on trial averaging to obtain reliable results. However, some applications such as brain-computer interfaces (BCIs) require single-trial estimation methods. In this paper, we present SCoT—a source connectivity toolbox for Python. This toolbox implements routines for blind source...

  11. SCoT: A Python Toolbox for EEG Source Connectivity

    Directory of Open Access Journals (Sweden)

    Martin eBillinger

    2014-03-01

    Full Text Available Analysis of brain connectivity has become an important research tool in neuroscience. Connectivity can be estimated between cortical sources reconstructed from the electroencephalogram (EEG. Such analysis often relies on trial averaging to obtain reliable results. However, some applications such as brain-computer interfaces (BCIs require single-trial estimation methods.In this paper, we present SCoT – a source connectivity toolbox for Python. This toolbox implements routines for blind source decomposition and connectivity estimation with theMVARICA approach. Additionally, a novel extension called CSPVARICA is available for labeled data. SCoT estimates connectivity from various spectral measures relying on vector autoregressive (VAR models. Optionally, these VAR models can be regularized to facilitate ill posed applications such as single-trial fitting.We demonstrate basic usage of SCoT on motor imagery (MI data. Furthermore, we show simulation results of utilizing SCoT for feature extraction in a BCI application. These results indicate that CSPVARICA and correct regularization can significantly improve MI classification. While SCoT was mainly designed for application in BCIs, it contains useful tools for other areas of neuroscience. SCoT is a software package that (1 brings combined source decomposition and connectivtiy estimation to the open Python platform, and (2 offers tools for single-trial connectivity estimation. The source code is released under the MIT license and is available online at github.com/SCoT-dev/SCoT.

  12. Identification of genetically and oceanographically distinct blooms of jellyfish.

    Science.gov (United States)

    Lee, Patricia L M; Dawson, Michael N; Neill, Simon P; Robins, Peter E; Houghton, Jonathan D R; Doyle, Thomas K; Hays, Graeme C

    2013-03-06

    Reports of nuisance jellyfish blooms have increased worldwide during the last half-century, but the possible causes remain unclear. A persistent difficulty lies in identifying whether blooms occur owing to local or regional processes. This issue can be resolved, in part, by establishing the geographical scales of connectivity among locations, which may be addressed using genetic analyses and oceanographic modelling. We used landscape genetics and Lagrangian modelling of oceanographic dispersal to explore patterns of connectivity in the scyphozoan jellyfish Rhizostoma octopus, which occurs en masse at locations in the Irish Sea and northeastern Atlantic. We found significant genetic structure distinguishing three populations, with both consistencies and inconsistencies with prevailing physical oceanographic patterns. Our analyses identify locations where blooms occur in apparently geographically isolated populations, locations where blooms may be the source or result of migrants, and a location where blooms do not occur consistently and jellyfish are mostly immigrant. Our interdisciplinary approach thus provides a means to ascertain the geographical origins of jellyfish in outbreaks, which may have wide utility as increased international efforts investigate jellyfish blooms.

  13. Bloom syndrome.

    Science.gov (United States)

    Arora, Harleen; Chacon, Anna H; Choudhary, Sonal; McLeod, Michael P; Meshkov, Lauren; Nouri, Keyvan; Izakovic, Jan

    2014-07-01

    Bloom Syndrome (BS, MIM #210900) is an autosomal recessive genetic disorder caused by a mutation in the BLM gene, which codes for the DNA repair enzyme RecQL3 helicase. Without proper DNA repair mechanisms, abnormal DNA exchange takes place between sister chromatids and results in genetic instability that may lead to cancer, especially lymphoma and acute myelogenous leukemia, lower and upper gastrointestinal tract neoplasias, cutaneous tumors, and neoplasias in the genitalia and urinary tract. BS patients are usually of Ashkenazi Jewish descent and exhibit narrow facial features, elongated limbs, and several dermatologic complications including photosensitivity, poikiloderma, and telangiectatic erythema. The most concerning manifestation of BS is multiple malignancies, which require frequent screenings and strict vigilance by the physician. Therefore, distinguishing between BS and other dermatologic syndromes of similar presentation such as Rothmund-Thomson Syndrome, Erythropoietic Protoporphyria, and Cockayne Syndrome is paramount to disease management and to prolonging life. BS can be diagnosed through a variety of DNA sequencing methods, and genetic testing is available for high-risk populations. This review consolidates several sources on BS sequelae and aims to suggest the importance of differentiating BS from other dermatologic conditions. This paper also elucidates the recently discovered BRAFT and FANCM protein complexes that link BS and Fanconi anemia.

  14. Source apportionment and dynamic changes of carbonaceous aerosols during the haze bloom-decay process in China based on radiocarbon and organic molecular tracers

    Science.gov (United States)

    Liu, Junwen; Li, Jun; Liu, Di; Ding, Ping; Shen, Chengde; Mo, Yangzhi; Wang, Xinming; Luo, Chunling; Cheng, Zhineng; Szidat, Sönke; Zhang, Yanlin; Chen, Yingjun; Zhang, Gan

    2016-03-01

    Fine carbonaceous aerosols (CAs) is the key factor influencing the currently filthy air in megacities in China, yet few studies simultaneously focus on the origins of different CAs species using specific and powerful source tracers. Here, we present a detailed source apportionment for various CAs fractions, including organic carbon (OC), water-soluble OC (WSOC), water-insoluble OC (WIOC), elemental carbon (EC) and secondary OC (SOC) in the largest cities of North (Beijing, BJ) and South China (Guangzhou, GZ), using the measurements of radiocarbon and anhydrosugars. Results show that non-fossil fuel sources such as biomass burning and biogenic emission make a significant contribution to the total CAs in Chinese megacities: 56 ± 4 in BJ and 46 ± 5 % in GZ, respectively. The relative contributions of primary fossil carbon from coal and liquid petroleum combustions, primary non-fossil carbon and secondary organic carbon (SOC) to total carbon are 19, 28 and 54 % in BJ, and 40, 15 and 46 % in GZ, respectively. Non-fossil fuel sources account for 52 in BJ and 71 % in GZ of SOC, respectively. These results suggest that biomass burning has a greater influence on regional particulate air pollution in North China than in South China. We observed an unabridged haze bloom-decay process in South China, which illustrates that both primary and secondary matter from fossil sources played a key role in the blooming phase of the pollution episode, while haze phase is predominantly driven by fossil-derived secondary organic matter and nitrate.

  15. Incorporating priors for EEG source imaging and connectivity analysis

    Directory of Open Access Journals (Sweden)

    Xu eLei

    2015-08-01

    Full Text Available Electroencephalography source imaging (ESI is a useful technique to localize the generators from a given scalp electric measurement and to investigate the temporal dynamics of the large-scale neural circuits. By introducing reasonable priors from other modalities, ESI reveals the most probable sources and communication structures at every moment in time. Here, we review the available priors from such techniques as magnetic resonance imaging (MRI, functional MRI (fMRI, and positron emission tomography (PET. The modality's specific contribution is analyzed from the perspective of source reconstruction. For spatial priors, such as EEG-correlated fMRI, temporally coherent networks and resting-state fMRI are systematically introduced in the ESI. Moreover, the fiber tracking (diffusion tensor imaging, DTI and neuro-stimulation techniques (transcranial magnetic stimulation, TMS are also introduced as the potential priors, which can help to draw inferences about the neuroelectric connectivity in the source space. We conclude that combining EEG source imaging with other complementary modalities is a promising approach towards the study of brain networks in cognitive and clinical neurosciences.

  16. Cortical current source connectivity by means of partial coherence fields

    CERN Document Server

    Pascual-Marqui, Roberto D; Valdes-Sosa, Pedro A; Bosch-Bayard, Jorge; Riera-Diaz, Jorge J

    2011-01-01

    An important field of research in functional neuroimaging is the discovery of integrated, distributed brain systems and networks, whose different regions need to work in unison for normal functioning. The EEG is a non-invasive technique that can provide information for massive connectivity analyses. Cortical signals of time varying electric neuronal activity can be estimated from the EEG. Although such techniques have very high time resolution, two cortical signals even at distant locations will appear to be highly similar due to the low spatial resolution nature of the EEG. In this study a method for eliminating the effect of common sources due to low spatial resolution is presented. It is based on an efficient estimation of the whole-cortex partial coherence matrix. Using as a starting point any linear EEG tomography that satisfies the EEG forward equation, it is shown that the generalized partial coherences for the cortical grey matter current density time series are invariant to the selected tomography. I...

  17. 26 CFR 1.864-5 - Foreign source income effectively connected with U.S. business.

    Science.gov (United States)

    2010-04-01

    ... 26 Internal Revenue 9 2010-04-01 2010-04-01 false Foreign source income effectively connected with... December 30, 1996 § 1.864-5 Foreign source income effectively connected with U.S. business. (a) In general. This section applies only to a nonresident alien individual or a foreign corporation that is engaged...

  18. Disk-Jet connection in outbursting Black Hole sources

    CERN Document Server

    D, Radhika; Seetha, S

    2013-01-01

    We explored the `spectro - temporal' behaviour of outbursting Black Hole sources in X-rays, at the time of jet ejections which are observed as radio flares. The energy dependent evolution of the properties of all the sources studied, shows that during the ejections the QPO frequencies `disappear' as well as the disk (thermal) emission increases, implying the soft nature of the spectrum. These results can be understood based on the TCAF model (Chakrabarti & Titarchuk 1995), in the presence of magnetic field.

  19. Lunar ferroan anorthosites and mare basalt sources - The mixed connection

    Science.gov (United States)

    Ryder, Graham

    1991-01-01

    Global overturn of a hot, gravitationally unstable lunar mantle immediately following the solidification of a magma ocean explains several characteristics of lunar petrology. Lunar mare basalt sources are inferred to be depleted in europium and alumina. These depletions are consensually attributed to complementary plagioclase floating from a magma ocean. However, in contrast to the mare basalt source parent magma, the ferroan anorthosite parent magma was more evolved by virtue of its lower Mg/Fe ratio and Ni abundances, although less evolved in its poverty of clinopyroxene constituents, flat rare earth pattern, and lower incompatible element abundances. The europium anomaly in mare sources is inferred to be present at 400 km depth, too deep to have been directly influenced by plagioclase crystallization. Massive overturning of the post-magma ocean mantle would have carried down clinopyroxene, ilmenite, and phases containing fractionated rare earths, europium anomalies, and some heat-producing radionuclides.

  20. Lunar ferroan anorthosites and mare basalt sources - The mixed connection

    Science.gov (United States)

    Ryder, Graham

    1991-11-01

    Global overturn of a hot, gravitationally unstable lunar mantle immediately following the solidification of a magma ocean explains several characteristics of lunar petrology. Lunar mare basalt sources are inferred to be depleted in europium and alumina. These depletions are consensually attributed to complementary plagioclase floating from a magma ocean. However, in contrast to the mare basalt source parent magma, the ferroan anorthosite parent magma was more evolved by virtue of its lower Mg/Fe ratio and Ni abundances, although less evolved in its poverty of clinopyroxene constituents, flat rare earth pattern, and lower incompatible element abundances. The europium anomaly in mare sources is inferred to be present at 400 km depth, too deep to have been directly influenced by plagioclase crystallization. Massive overturning of the post-magma ocean mantle would have carried down clinopyroxene, ilmenite, and phases containing fractionated rare earths, europium anomalies, and some heat-producing radionuclides.

  1. Connecting earthquake source products to local tsunami warning

    Science.gov (United States)

    Melgar, D.; Allen, R. M.

    2015-12-01

    Issuing warning of a tsunami in advance of its arrival to the coastlines immediately adjacent to large earthquakes remains a challenging problem. The heterogeneous development state of regional geophysical monitoring infrastructure across subduction zones worldwide means that a flexible approach to warning, capable of ingesting multiple data types and earthquake source products, is the most appealing. We will present results from the study of 3 recent large events that have been observed with diverse geophysical measurements; the 2011 Mw9.0 Tohoku-oki, the 2010 Mw8.8 Maule and 2014 Mw8.2 Iquique events. First, we will show that earthquake slip models derived from combination of land (GPS and strong motion) as well as off-shore (tide gauges, ocean-bottom pressure, and GPS buoy) can be coupled to tsunami propagation models to produce simulations that closely match the measured run-up at the local coastlines. Using these models as a baseline for validation we will demonstrate a methodology that takes advantage of simpler, but more readily available earthquake source products such as rapid point-source magnitude estimates from coastal GPS observations and regional moment tensors. We will show that while trading-off precision for speed, these simpler earthquake source models produce inundation forecasts reliable enough to be used for warning within minutes of earthquake onset. Most subduction zones around the world already have some geophysical infrastructure and are producing some form of real-time earthquake source product, our results strongly argue that by coupling these data products to tsunami propagation models local tsunami warning is possible at most subduction zones with already available infrastructure.

  2. Fault Ride-Through of a Grid-connected Photovoltaic System with Quasi Z Source Inverter

    DEFF Research Database (Denmark)

    Al-Durra, Ahmed; Fayyad, Yara; Muyeen, S.M.;

    2016-01-01

    This article presents fault ride-through schemes for a three-phase quasi Z source single-stage photovoltaic (PV) inverter that is connected to the grid after the distribution network. The quasi Z source inverter employs a unique LC network to couple the inverter main circuit to the input of the PV...

  3. Investigation of Grid-connected Voltage Source Converter Performance under Unbalanced Faults

    DEFF Research Database (Denmark)

    Jia, Jundi; Yang, Guangya; Nielsen, Arne Hejde

    2016-01-01

    Renewable energy sources (RES) and HVDC links are typically interfaced with the grid by power converters, whose performance during grid faults is significantly different from that of traditional synchronous generators. This paper investigates the performance of grid-connected voltage source...

  4. Connecting Lunar Meteorites to Source Terrains on the Moon

    Science.gov (United States)

    Jolliff, B. L.; Carpenter, P. K.; Korotev, R. L.; North-Valencia, S. N.; Wittmann, A.; Zeigler, R. A.

    2014-01-01

    that excavated and mixed rocks from depth within the lunar crust and possibly the upper mantle. One of the key questions is whether the mafic materials are ferroan or magnesian, which remote sensing does not clearly distinguish, and if mafic, whether they might contain mantlederived components such as olivine (dunite). Many but not all have mainly ferroan mafic components, consistent with a ferroan crustal source that is complementary to the ferroan anorthositic suite and that represents primary magma-ocean-derived feldspathic crust. Meteorites such as ALH 81005 [5] and Shisr 161 [6], however, contain coarse-grained magnesian mafic clasts (Fig. 1a) derived from deeply seated and melted material associated with impact basins. Comparison to LP gamma-ray data [2] supports an origin for magnesian feldspathic meteorites such as these (e.g., Shisr 161) as shown in Fig. 1b. Sayh al Uhaymir (SaU) 169. Another distinctive but much less common composition is represented by relatively mafic impact-melt breccia that is rich in incompatible elements known as KREEP. These meteorites can be related to the western nearside Procellarum KREEP Terrane, especially through a combination of Fe and Th contents. Among the most enriched is SaU 169, which has been related to high- Th impact-melt breccia found at the Apollo 12 site [7]. Through detailed EPMA and ion microprobe analysis we have shown that these two rock types are related in age and origin.

  5. 26 CFR 1.864-4 - U.S. source income effectively connected with U.S. business.

    Science.gov (United States)

    2010-04-01

    ... this subparagraph is not effectively connected with the active conduct by a nonresident alien... 26 Internal Revenue 9 2010-04-01 2010-04-01 false U.S. source income effectively connected with U... December 30, 1996 § 1.864-4 U.S. source income effectively connected with U.S. business. (a) In...

  6. Granger causal time-dependent source connectivity in the somatosensory network

    Science.gov (United States)

    Gao, Lin; Sommerlade, Linda; Coffman, Brian; Zhang, Tongsheng; Stephen, Julia M.; Li, Dichen; Wang, Jue; Grebogi, Celso; Schelter, Bjoern

    2015-05-01

    Exploration of transient Granger causal interactions in neural sources of electrophysiological activities provides deeper insights into brain information processing mechanisms. However, the underlying neural patterns are confounded by time-dependent dynamics, non-stationarity and observational noise contamination. Here we investigate transient Granger causal interactions using source time-series of somatosensory evoked magnetoencephalographic (MEG) elicited by air puff stimulation of right index finger and recorded using 306-channel MEG from 21 healthy subjects. A new time-varying connectivity approach, combining renormalised partial directed coherence with state space modelling, is employed to estimate fast changing information flow among the sources. Source analysis confirmed that somatosensory evoked MEG was mainly generated from the contralateral primary somatosensory cortex (SI) and bilateral secondary somatosensory cortices (SII). Transient Granger causality shows a serial processing of somatosensory information, 1) from contralateral SI to contralateral SII, 2) from contralateral SI to ipsilateral SII, 3) from contralateral SII to contralateral SI, and 4) from contralateral SII to ipsilateral SII. These results are consistent with established anatomical connectivity between somatosensory regions and previous source modeling results, thereby providing empirical validation of the time-varying connectivity analysis. We argue that the suggested approach provides novel information regarding transient cortical dynamic connectivity, which previous approaches could not assess.

  7. Granger causal time-dependent source connectivity in the somatosensory network.

    Science.gov (United States)

    Gao, Lin; Sommerlade, Linda; Coffman, Brian; Zhang, Tongsheng; Stephen, Julia M; Li, Dichen; Wang, Jue; Grebogi, Celso; Schelter, Bjoern

    2015-05-21

    Exploration of transient Granger causal interactions in neural sources of electrophysiological activities provides deeper insights into brain information processing mechanisms. However, the underlying neural patterns are confounded by time-dependent dynamics, non-stationarity and observational noise contamination. Here we investigate transient Granger causal interactions using source time-series of somatosensory evoked magnetoencephalographic (MEG) elicited by air puff stimulation of right index finger and recorded using 306-channel MEG from 21 healthy subjects. A new time-varying connectivity approach, combining renormalised partial directed coherence with state space modelling, is employed to estimate fast changing information flow among the sources. Source analysis confirmed that somatosensory evoked MEG was mainly generated from the contralateral primary somatosensory cortex (SI) and bilateral secondary somatosensory cortices (SII). Transient Granger causality shows a serial processing of somatosensory information, 1) from contralateral SI to contralateral SII, 2) from contralateral SI to ipsilateral SII, 3) from contralateral SII to contralateral SI, and 4) from contralateral SII to ipsilateral SII. These results are consistent with established anatomical connectivity between somatosensory regions and previous source modeling results, thereby providing empirical validation of the time-varying connectivity analysis. We argue that the suggested approach provides novel information regarding transient cortical dynamic connectivity, which previous approaches could not assess.

  8. Equivalence perspectives in communication, source-channel connections and universal source-channel separation

    CERN Document Server

    Agarwal, Mukul; Mitter, Sanjoy

    2009-01-01

    An operational perspective is used to understand the relationship between source and channel coding. This is based on a direct reduction of one problem to another that uses random coding (and hence common randomness) but unlike all prior work, does not involve any functional computations, in particular, no mutual-information computations. This result is then used to prove a universal source-channel separation theorem in the rate-distortion context where universality is in the sense of a compound ``general channel.''

  9. The GeV-TeV Connection in Galactic gamma-ray Sources

    Energy Technology Data Exchange (ETDEWEB)

    Funk, S.; /KIPAC, Menlo Park; Reimer, O.; /Stanford U., HEPL /KIPAC, Menlo Park; Torres, Diego F.; /ICREA, Barcelona; Hinton, J.A.; /Leeds U.

    2007-09-28

    Recent observations by atmospheric Cherenkov telescopes such as H.E.S.S. and MAGIC have revealed a large number of new sources of very-high-energy (VHE) gamma-rays above 100 GeV, mostly concentrated along the Galactic plane. At lower energies (100 MeV - 10 GeV) the satellite-based instrument EGRET revealed a population of sources clustering along the Galactic Plane. Given their adjacent energy bands a systematic correlation study between the two source classes seems appropriate. While only a few of the sources connect, both in terms of positional coincidence and spectral consistency, most of the detections occur only in one or the other energy domain. In these cases, for the first time consistent upper limits in the other energy band have been derived. Here, the populations of Galactic sources in both energy domains are characterized on observational as well as on theoretical grounds, followed by an interpretation on their similarities and differences. The observational data at this stage suggest rather different major source populations at GeV and TeV energies. With regards to preparations for the upcoming GLAST mission that will cover the energy range bridging GeV and TeV instruments this paper investigates the connection between the population of sources in these bands and concludes with predictions for commonly observable sources for GLAST-LAT detections.

  10. Fault Ride-Through of a Grid-connected Photovoltaic System with Quasi Z Source Inverter

    DEFF Research Database (Denmark)

    Al-Durra, Ahmed; Fayyad, Yara; Muyeen, S.M.

    2016-01-01

    This article presents fault ride-through schemes for a three-phase quasi Z source single-stage photovoltaic (PV) inverter that is connected to the grid after the distribution network. The quasi Z source inverter employs a unique LC network to couple the inverter main circuit to the input of the PV...... panel. By controlling the shoot-through duty cycle, the quasi Z source inverter can theoretically produce any desired output AC voltage, even greater than the line voltage. Three different control strategies to improve the low-voltage ride-through capability are proposed when there is voltage sag from...

  11. Peculiarities of the Woody Plants Re-Bloom

    Directory of Open Access Journals (Sweden)

    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

  12. Resting-state EEG source localization and functional connectivity in schizophrenia-like psychosis of epilepsy.

    Directory of Open Access Journals (Sweden)

    Leonides Canuet

    Full Text Available BACKGROUND: It is unclear whether, like in schizophrenia, psychosis-related disruption in connectivity between certain regions, as an index of intrinsic functional disintegration, occurs in schizophrenia-like psychosis of epilepsy (SLPE. In this study, we sought to determine abnormal patterns of resting-state EEG oscillations and functional connectivity in patients with SLPE, compared with nonpsychotic epilepsy patients, and to assess correlations with psychopathological deficits. METHODOLOGY/PRINCIPAL FINDINGS: Resting EEG was recorded in 21 patients with focal epilepsy and SLPE and in 21 clinically-matched non-psychotic epilepsy controls. Source current density and functional connectivity were determined using eLORETA software. For connectivity analysis, a novel nonlinear connectivity measure called "lagged phase synchronization" was used. We found increased theta oscillations in regions involved in the default mode network (DMN, namely the medial and lateral parietal cortex bilaterally in the psychotic patients relative to their nonpsychotic counterparts. In addition, patients with psychosis had increased beta temporo-prefrontal connectivity in the hemisphere with predominant seizure focus. This functional connectivity in temporo-prefrontal circuits correlated with positive symptoms. Additionally, there was increased interhemispheric phase synchronization between the auditory cortex of the affected temporal lobe and the Broca's area correlating with auditory hallucination scores. CONCLUSIONS/SIGNIFICANCE: In addition to dysfunction of parietal regions that are part of the DMN, resting-state disrupted connectivity of the medial temporal cortex with prefrontal areas that are either involved in the DMN or implicated in psychopathological dysfunction may be critical to schizophrenia-like psychosis, especially in individuals with temporal lobe epilepsy. This suggests that DMN deficits might be a core neurobiological feature of the disorder, and

  13. Fat bloom on chocolate confectionery systems - From core to surface

    OpenAIRE

    Dahlenborg, Hanna

    2014-01-01

    Abstract Fat bloom on chocolate is a major problem for the confectionery industry since the unappetising appearance and negative sensory effects lead to rejection by customers. The presence of fat bloom on chocolate confectionery systems is usually connected to migration of liquid fat due to the difference in composition between filling triacylglycerols (TAGs) and cocoa butter TAGs. The filling TAGs migrate into the chocolate shell where they can dissolve cocoa butter crystals. Consequ...

  14. Beamformer source analysis and connectivity on concurrent EEG and MEG data during voluntary movements.

    Directory of Open Access Journals (Sweden)

    Muthuraman Muthuraman

    Full Text Available Electroencephalography (EEG and magnetoencephalography (MEG are the two modalities for measuring neuronal dynamics at a millisecond temporal resolution. Different source analysis methods, to locate the dipoles in the brain from which these dynamics originate, have been readily applied to both modalities alone. However, direct comparisons and possible advantages of combining both modalities have rarely been assessed during voluntary movements using coherent source analysis. In the present study, the cortical and sub-cortical network of coherent sources at the finger tapping task frequency (2-4 Hz and the modes of interaction within this network were analysed in 15 healthy subjects using a beamformer approach called the dynamic imaging of coherent sources (DICS with subsequent source signal reconstruction and renormalized partial directed coherence analysis (RPDC. MEG and EEG data were recorded simultaneously allowing the comparison of each of the modalities separately to that of the combined approach. We found the identified network of coherent sources for the finger tapping task as described in earlier studies when using only the MEG or combined MEG+EEG whereas the EEG data alone failed to detect single sub-cortical sources. The signal-to-noise ratio (SNR level of the coherent rhythmic activity at the tapping frequency in MEG and combined MEG+EEG data was significantly higher than EEG alone. The functional connectivity analysis revealed that the combined approach had more active connections compared to either of the modalities during the finger tapping (FT task. These results indicate that MEG is superior in the detection of deep coherent sources and that the SNR seems to be more vital than the sensitivity to theoretical dipole orientation and the volume conduction effect in the case of EEG.

  15. Allan Bloom's Quarrel with History.

    Science.gov (United States)

    Thompson, James

    1988-01-01

    Responds to Allan Bloom's "The Closing of the American Mind." Concludes that despite cranky comments about bourgeois culture, the focus of Bloom's attack is on historicism, which undercuts his nostalgic vision of a prosperous and just America. Condemns Bloom's exclusion of Blacks, Hispanics, and women from America's cultural heritage.…

  16. Altered Resting-State EEG Source Functional Connectivity In Schizophrenia: The Effect Of Illness Duration

    Directory of Open Access Journals (Sweden)

    Giorgio eDi Lorenzo

    2015-05-01

    Full Text Available Despite the increasing body of evidence supporting the hypothesis of schizophrenia as a disconnection syndrome, studies of resting-state EEG Source Functional Connectivity (EEG-SFC in people affected by schizophrenia are sparse. The aim of the present study was to investigate resting-state EEG-SFC in 77 stable, medicated patients with schizophrenia (SCZ compared to 78 healthy volunteers (HV. In order to study the effect of illness duration, SCZ were divided in those with a short duration of disease (SDD; n = 25 and those with a long duration of disease (LDD; n = 52. Resting-state EEG recordings in eyes closed condition were analyzed and lagged phase synchronization (LPS indices were calculated for each ROI pair in the source-space EEG data. In delta and theta bands, SCZ had greater EEG-SFC than HV; a higher theta band connectivity in frontal regions was observed in LDD compared with SDD. In the alpha band, SCZ showed lower frontal EEG-SFC compared with HV whereas no differences were found between LDD and SDD. In the beta1 band, SCZ had greater EEG-SFC compared with HVs and in the beta2 band, LDD presented lower frontal and parieto-temporal EEG-SFC compared with HV. In the gamma band, SDD had greater connectivity values compared with LDD and HV. This study suggests that resting state brain network connectivity is abnormally organized in schizophrenia, with different patterns for the different EEG frequency components and that EEG can be a powerful tool to further elucidate the complexity of such disordered connectivity.

  17. Dynamics of voltage source converter in a grid connected solar photovoltaic system

    DEFF Research Database (Denmark)

    Haribabu, Divyanagalakshmi; Vangari, Adithya; Sakamuri, Jayachandra N.

    2015-01-01

    This paper emphasises the modelling and control of a voltage source converter (VSC) for three phase grid connected PV system. The transfer functions for inner current control and outer DC link voltage control for VSC are derived. The controllers for VSC are designed based on PI and K factor contr...... conditions. The effectiveness of the proposed controller is illustrated by evaluating the response of PV system for power system voltage sag and swell conditions as well as grid faults.......This paper emphasises the modelling and control of a voltage source converter (VSC) for three phase grid connected PV system. The transfer functions for inner current control and outer DC link voltage control for VSC are derived. The controllers for VSC are designed based on PI and K factor control...... methods and the performance of VSC using both the methods are presented with the simulations performed using PSCAD/EMTDC. The design of LC filter to meet the specified THD requirement for grid connected VSC is presented and the corresponding harmonic analysis is performed for different solar radiation...

  18. Medical connections: use of the internet and traditional sources of health information by rural Alabama households.

    Science.gov (United States)

    Hall, Laura M; Dunkelberger, John D; Wheat, John R

    2005-01-01

    Rural household adoption of the PC and Internet for accessing medical and healthcare information was investigated using survey data collected from 305 households randomly selected from non-metropolitan, rural counties across Alabama. The diffusion-adoption model for new technologies was employed to create five adoption stages relevant to this technology and its applications to communication of information in the health field. Descriptive household characteristics of age, education, income, and children revealed differences between adoption stages, with age and education having major impacts. Use of traditional sources of health information and the Internet were compared in relation to age and availability of medical services. Older, less educated households lagged behind in use of the Internet for health information. Medical professionals, doctors and pharmacists, were the most utilized information source by rural households; but those households connected to the Internet used on-line sources, even e-mail to communicate with their doctors.

  19. Connectivity from source to sink in a lowland area: the Loire river basin (France)

    Science.gov (United States)

    Gay, Aurore; Cerdan, Olivier; Degan, Francesca; Salvador, Sebastien

    2014-05-01

    Sediment connectivity relates to the transfer of sediments from sources to sinks via runoff and in channel transport. It is highly dependent on spatial variability of landscape properties such as differences in morphology, land use and infiltration/runoff characteristics but may also vary in time due to differences in rainfall amount/intensity and changes in vegetation cover throughout the year. In the Loire river basin, we found that sediment fluxes displayed strong variations in space but also at the interannual and seasonnal time scales (Gay et al. 2013). In this context, our goal is to better understand and quantify hillslope sediment redistributions within this lowland area thanks to the use of semi distributed connectivity approach. To this aim, Borselli's index of connectivity (IC, Borselli et al., 2008) is selected to assess hillslope connectivity at annual and seasonal time scales. Several improvements are proposed to take into account the coupling of the structural landscape connectivity and its hydrosedimentary response. Parameters such as rainfall intensity and differences in seasonal land cover are integrated into the model to account for landscape variations through time. Infiltration and runoff indices were also tested. Preliminary results confirm the variability of landscape connectivity throughout the year. The integration of the index of infiltration and runoff properties of landscape (IDPR) as defined by Mardhel et al. 2004 seems to improve the IC model outputs. From this first step, in-stream sediment connectivity index should be developed for a better understanding and assessment of sediment redistributions at the entire catchment scale. L. Borselli L., Cassi P., Torri D. Prolegomena to sediment and flow connectivity in the landscape: a GIS and field numerical assessment. Catena, 75 (2008), pp. 268-277 Gay A., Cerdan O., Delmas M., Desmet M., Variability of sediment yields in the Loire river basin (France): the role of small scale catchments

  20. Investigation of Grid-connected Voltage Source Converter Performance under Unbalanced Faults

    DEFF Research Database (Denmark)

    Jia, Jundi; Yang, Guangya; Nielsen, Arne Hejde

    2016-01-01

    Renewable energy sources (RES) and HVDC links are typically interfaced with the grid by power converters, whose performance during grid faults is significantly different from that of traditional synchronous generators. This paper investigates the performance of grid-connected voltage source...... that the performance of VSCs varies with their control strategies. Negative-sequence current control is necessary to restrict converter current in each phase under unbalanced faults. Among presented control strategies, the balanced current control strategy complies with the present voltage support requirement best...... converters (VSCs) under unbalanced faults. Conventional positive-sequence synchronous reference frame (SRF) control is presented first, followed by three different negative-sequence current control strategies considering reactive power injection and converter current limit. The simulation results indicate...

  1. Connecting Organic Aerosol Climate-Relevant Properties to Chemical Mechanisms of Sources and Processing

    Energy Technology Data Exchange (ETDEWEB)

    Thornton, Joel [Univ. of Washington, Seattle, WA (United States)

    2015-01-26

    The research conducted on this project aimed to improve our understanding of secondary organic aerosol (SOA) formation in the atmosphere, and how the properties of the SOA impact climate through its size, phase state, and optical properties. The goal of this project was to demonstrate that the use of molecular composition information to mechanistically connect source apportionment and climate properties can improve the physical basis for simulation of SOA formation and properties in climate models. The research involved developing and improving methods to provide online measurements of the molecular composition of SOA under atmospherically relevant conditions and to apply this technology to controlled simulation chamber experiments and field measurements. The science we have completed with the methodology will impact the simulation of aerosol particles in climate models.

  2. 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…

  3. Bloom syndrome in two siblings.

    Science.gov (United States)

    Sultan, Sheikh Javeed; Sultan, Sheikh Tariq

    2010-01-01

    Bloom syndrome (congenital telangiectatic erythema) is a rare autosomal recessive disorder characterized by telangiectasias and photosensitivity, growth deficiency of prenatal onset, variable degrees of immunodeficiency, and increased susceptibility to neoplasms of many sites and types. We are reporting Bloom syndrome in two brothers from Kashmir (India), 8 and 6 years of age, who presented with erythematous rashes on the face, photosensitivity, and growth retardation.

  4. Tympanomastoid cholesterol granuloma: radiological and intraoperative findings of blood source connection.

    Science.gov (United States)

    Iannella, Giannicola; Stasolla, Alessandro; Pasquariello, Benedetta; Re, Massimo; Magliulo, Giuseppe

    2016-09-01

    The hypothesis that the close contiguity between the cholesterol granulomas and some rich blood sources provided the trigger to the aggressive nature of tympanomastoid cholesterol granulomas has been recently reported. To corroborate this new etiopathogenetic theory we retrospectively reviewed a series of 14 patients with primary middle ear and mastoid cholesterol granulomas and investigated the temporal bone marrow invasion and its hematopoietic potentialities and a possible cholesterol granulomas contiguity with relevant vascular structures such as the carotid artery, sigmoid jugular system, mastoid or dural vein. Eight cases did not show radiological sign of bone marrow invasion or hematopoietic potentialities visible in MRI. Besides no intraoperative vascular connections that could explain an initial bleeding source were found. Cholesterol granulomas bone marrow invasion was present in six patients. A bone marrow hematopoietic potentiality was showed in four of these patients, whereas, an evident anatomical contiguity of the cholesterol granuloma with some important temporal bone vascular structures was visible in five cases. Analysis of cardiovascular risk factors showed that four patients presented one or more of the risk factors analysed.

  5. Then the Wilderness Shall Bloom like a Rosy Bower

    DEFF Research Database (Denmark)

    Nielsen, Kirsten

    2014-01-01

    intertextual connections to the rest of the book. In my article, I have analysed how the Danish poet N.F.S. Grundtvig reworks Isa 35 in his hymn “Then the wilderness shall bloom like a rosy bower”, and how he reinterprets the wild animals as the Enemy (the Devil). In my view, the animals in Isa 35 have...

  6. Linking high-frequency DOC dynamics to the age of connected water sources

    Science.gov (United States)

    Tunaley, C.; Tetzlaff, D.; Lessels, J.; Soulsby, C.

    2016-07-01

    We combined high-frequency dissolved organic matter fluorescence (FDOM) data with stable isotope observations to identify the sources and ages of runoff that cause temporal variability in dissolved organic carbon (DOC) within a peat-dominated Scottish catchment. FDOM was strongly correlated (r2 ˜ 0.8) with DOC, allowing inference of a 15 min time series. We captured 34 events over a range of hydrological conditions. Along with marked seasonality, different event responses were observed during summer depending on dry or wet antecedent conditions. The majority of events exhibited anticlockwise hysteresis as a result of the expansion of the riparian saturation zone, mobilizing previously unconnected DOC sources. Water ages from the main runoff sources were extracted from a tracer-aided hydrological model. Particularly useful were ages of overland flow, which were negatively correlated with DOC concentration. Overland flow age, which ranged between 0.2 and 360 days, reflected antecedent conditions, with younger water generally mobilizing the highest DOC concentrations in summer events. During small events with dry antecedent conditions, DOC response was proportionally higher due to the displacement and mixing of small volumes of previously unconnected highly concentrated riparian soil waters by new precipitation. During large events with wet antecedent conditions, the riparian saturation zone expands to organic layers on the hillslopes causing peaks in DOC. However, these peaks were limited by dilution and supply. This study highlights the utility of linking high-frequency DOC measurements with other tracers, allowing the effects of hydrologic connectivity and antecedent conditions on delivery of DOC to streams to be assessed.

  7. Optimal operation management of fuel cell/wind/photovoltaic power sources connected to distribution networks

    Science.gov (United States)

    Niknam, Taher; Kavousifard, Abdollah; Tabatabaei, Sajad; Aghaei, Jamshid

    2011-10-01

    In this paper a new multiobjective modified honey bee mating optimization (MHBMO) algorithm is presented to investigate the distribution feeder reconfiguration (DFR) problem considering renewable energy sources (RESs) (photovoltaics, fuel cell and wind energy) connected to the distribution network. The objective functions of the problem to be minimized are the electrical active power losses, the voltage deviations, the total electrical energy costs and the total emissions of RESs and substations. During the optimization process, the proposed algorithm finds a set of non-dominated (Pareto) optimal solutions which are stored in an external memory called repository. Since the objective functions investigated are not the same, a fuzzy clustering algorithm is utilized to handle the size of the repository in the specified limits. Moreover, a fuzzy-based decision maker is adopted to select the 'best' compromised solution among the non-dominated optimal solutions of multiobjective optimization problem. In order to see the feasibility and effectiveness of the proposed algorithm, two standard distribution test systems are used as case studies.

  8. Power angle control of grid-connected voltage source converter in a wind energy application

    Energy Technology Data Exchange (ETDEWEB)

    Svensson, Jan [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Electric Power Engineering

    1995-12-31

    In this thesis, the connection of a voltage source converter to the grid in a wind energy application is examined. The possibility of using a cheap control system without grid current measurements, is investigated. The control method is based on controlling the voltage angle of the inverter, which governs the active power flow. The highest frequency of the power variation, coming from wind turbine, is approx. 5 Hz. Since the proposed control method easily can handle such power variations it is very well suited for wind turbine applications. The characteristics of the system depend on the DC-link capacitor, the grid filter inductance and resistance. Large values of the resistance damp the system well but increase the energy losses. A high inductance leads to a reduced harmonic level on the grid but makes the system slower. By using feed-forward of the generator/rectifier current signal, the performance is increased compared to an ordinary PI-control. Combining the Linear Quadratic (LQ) control method with Kalman filtered input signals, a robust control method with a good performance is obtained. The LQ controller controls both the phase displacement angle and the modulation index, resulting in higher bandwidth, and the typical power angle resonance at the grid frequency disappears. 22 refs, 109 figs, 14 tabs

  9. Optimal DG Source Allocation for Grid Connected Distributed Generation with Energy Storage System

    Directory of Open Access Journals (Sweden)

    S. Ezhilarasan

    2015-05-01

    Full Text Available This study proposes an Energy Management System (EMS for allocation of DG source in a grid connected hybrid power system. Modeling and simulation for EMS is implemented using MATLAB/SIMULINK package. The objective of proposed EMS for micro grid is to optimize the fuel cost, improving the energy utilization efficiency and to manage the peak load demand by scheduling the generation according to the availability of the fuel. The proposed intelligent energy management system is designed to optimize the availability of energy to the load according to the level of priority and to manage the power flow. The developed management system performance was assessed using a hybrid system having PV panels, Wind Turbine (WT, battery and biomass gasifier. Real time field test has been conducted and the parameters i.e., solar irradiance, temperature, wind speed are gathered from 4.05 KW off grid and 2.0 KW On grid Solar Photovoltaic systems (SPV system and wind turbine. The dynamic behavior of the proposed model is examined under different operating conditions. The simulation results of proposed EMS using fuzzy logic expert system shows the minimization on the operating cost and emission level of micro grid by optimal scheduling of power generation and maintains the State of Charge (SOC of batteries in desired value which improves the battery life. The proposed multi objective intelligent energy management system aims to minimize the operational cost and the environmental impact of a micro grid.

  10. Modeling the Galaxy-Halo Connection: An open-source approach with Halotools

    Science.gov (United States)

    Hearin, Andrew

    2016-03-01

    Although the modern form of galaxy-halo modeling has been in place for over ten years, there exists no common code base for carrying out large-scale structure calculations. Considering, for example, the advances in CMB science made possible by Boltzmann-solvers such as CMBFast, CAMB and CLASS, there are clear precedents for how theorists working in a well-defined subfield can mutually benefit from such a code base. Motivated by these and other examples, I present Halotools: an open-source, object-oriented python package for building and testing models of the galaxy-halo connection. Halotools is community-driven, and already includes contributions from over a dozen scientists spread across numerous universities. Designed with high-speed performance in mind, the package generates mock observations of synthetic galaxy populations with sufficient speed to conduct expansive MCMC likelihood analyses over a diverse and highly customizable set of models. The package includes an automated test suite and extensive web-hosted documentation and tutorials (halotools.readthedocs.org). I conclude the talk by describing how Halotools can be used to analyze existing datasets to obtain robust and novel constraints on galaxy evolution models, and by outlining the Halotools program to prepare the field of cosmology for the arrival of Stage IV dark energy experiments.

  11. 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...

  12. 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...

  13. Further Verification of Bloom's Taxonomy

    Science.gov (United States)

    Roberts, Nancy

    1976-01-01

    Tests a curriculum designed to teach fifth and sixth grade students system dynamics thinking, an orientation that is congruent with the fourth and fifth levels of Bloom's "Taxonomy of Educational Objectives: Cognitive Domain".

  14. Improved Passive-Damped LCL Filter to Enhance Stability in Grid-Connected Voltage-Source Converters

    DEFF Research Database (Denmark)

    Beres, Remus Narcis; Wang, Xiongfei; Blaabjerg, Frede;

    2015-01-01

    This paper proposes an improved passive-damped LCL filter to be used as interface between the grid-connected voltage-source converters and the utility grid. The proposed filter replaces the LCL filter capacitor with a traditional C-type filter with the resonant circuit tuned in such a way that sw...

  15. Chlorophyll Blooms in the Oligotropic Gyres: Ocean oases?

    Science.gov (United States)

    Wilson, C.; Maximenko, N.

    2005-12-01

    Ocean color images from the SeaWiFS satellite have revealed that large blooms of chlorophyll sometimes develop in late summer northeast of Hawaii in the oligotrophic Pacific. While these blooms are a recurrent feature, appearing almost every year, their existence was only recently discovered from satellite imagery of ocean color. They have been observed in 11 of 16 years of satellite ocean color data (CZCS, OCTS and SeaWiFS), can last up to 4-5 months, and can get as big as the state of California. Since the blooms have never been purposely sampled, it remains uncertain what species they are composed of, what mechanisms supply nutrients to support the elevated biomass, and what their impacts are on higher trophic levels. However, conventional scenarios of upwelled nutrients or enhanced mixing deepening the mixed layer into the nutricline do not seem to be operable. Instead, research has suggested that the source of new nutrients is biologically mediated, either by nitrogen fixing organisms, or by the vertical migration of diatom mats below the nutricline. Physical dynamics affect the blooms on a basin-wide scale. The blooms only appear in the eastern gyre of the Pacific, a closed anticyclonic gyre that has enhanced convergence relative to the rest of the Pacific, suggesting that blooms develop in part from a large-scale aggregation of the buoyant organisms proposed to be associated with them. While these proposed biological and physical dynamics are speculative, if similar blooms appear in other oceans, analysis of the common features of their physical environments will help to better pinpoint the physical forcings involved. Analysis of the global fields of SeaWiFS satellite chlorophyll shows that while not nearly as common as in the North Pacific, potentially similar blooms occur in the North and South Atlantic, and the North Indian Oceans, but not in the S. Pacific. However, unlike in the N. Pacific, these blooms are not always associated with strong convergence

  16. Phase-lock loop of Grid-connected Voltage Source Converter under non-ideal grid condition

    DEFF Research Database (Denmark)

    Wang, Haojie; Sun, Hai; Han, Minxiao;

    2015-01-01

    phase information cannot be accurately tracked. Based on analysis of the cause of double-frequency ripple when unbalance exists in main grid, a phase-locked loop (PLL) detection technique is proposed. Under the conditions of unsymmetrical system voltage, varying system frequency, single-phase system......It is a normal practice that the DC micro-grid is connected to AC main grid through Grid-connected Voltage Source Converter (G-VSC) for voltage support. Accurate control of DC micro-grid voltage is difficult for G-VSC under unbalanced grid condition as the fundamental positive-sequence component...

  17. A Novel Method of Suppressing the Inrush Current of Transformers Using a Series-Connected Voltage-Source PWM Converter

    Science.gov (United States)

    Yamada, Hiroaki; Tanaka, Toshihiko; Funabiki, Shigeyuki

    This paper proposes a novel method of suppressing the inrush current of transformers. A small-rated voltage-source PWM converter is connected in series to the transformers through a matching transformer. As the connected PWM converter performs a resistor for the source current, no inrush phenomena occurs. The required-ratings of the PWM converter, which performs the damping resistor for the inrush phenomena, is one-four-hundredth as compared to that of the main transformers in single-phase circuits. In three-phase circuits, it is one-nine-hundredth. The basic principle of the proposed method is discussed. Digital computer simulation is implemented to confirm the validity and excellent practicability of the proposed method using the PSCAD/EMTDC. A prototype experimental-model is constructed and tested. The experimental results demonstrate that the proposed method can perfectly suppress the inrush phenomena.

  18. Connectivity Reveals Sources of Predictive Coding Signals in Early Visual Cortex During Processing of Visual Optic Flow.

    Science.gov (United States)

    Schindler, Andreas; Bartels, Andreas

    2016-05-24

    Superimposed on the visual feed-forward pathway, feedback connections convey higher level information to cortical areas lower in the hierarchy. A prominent framework for these connections is the theory of predictive coding where high-level areas send stimulus interpretations to lower level areas that compare them with sensory input. Along these lines, a growing body of neuroimaging studies shows that predictable stimuli lead to reduced blood oxygen level-dependent (BOLD) responses compared with matched nonpredictable counterparts, especially in early visual cortex (EVC) including areas V1-V3. The sources of these modulatory feedback signals are largely unknown. Here, we re-examined the robust finding of relative BOLD suppression in EVC evident during processing of coherent compared with random motion. Using functional connectivity analysis, we show an optic flow-dependent increase of functional connectivity between BOLD suppressed EVC and a network of visual motion areas including MST, V3A, V6, the cingulate sulcus visual area (CSv), and precuneus (Pc). Connectivity decreased between EVC and 2 areas known to encode heading direction: entorhinal cortex (EC) and retrosplenial cortex (RSC). Our results provide first evidence that BOLD suppression in EVC for predictable stimuli is indeed mediated by specific high-level areas, in accord with the theory of predictive coding.

  19. Bloom syndrome with lung involvement.

    Science.gov (United States)

    Nair, Girija; Lobo, Ivona; Jayalaksmi, T K; Uppe, Abhay; Jindal, Savita; Chandra, Abhishek; Swami, Shivani

    2009-07-01

    We report a case of a 24-year old male presented with cough and breathlessness with diabetes mellitus and diagnosed as a case of bloom syndrome. He was a product of consanguineous marriage, having short stature, dolicocephaly, polydactyly, prominent nose with telangiectasia face. The respiratory system examination revealed bilateral coarse crepitations and wheezes and the chest X-ray revealed emphysema with right middle zone inhomogenous opacity. Also, CT thorax examination revealed bilateral cystic bronchiectasis with bronchiolitis obliterans. Bloom's syndrome was diagnosed on the basis of clinical features.

  20. Bloom, Neatby, and the Lung Fishes.

    Science.gov (United States)

    Auer, John W.

    1991-01-01

    Discusses Allan Bloom's "The Closing of the American Mind" from a Canadian point of view, contending that Bloom's angry, irrational book on failures in U.S. society and higher education does not raise interesting or important ideas. Similarities and differences between Bloom and author Hilda Neatby are noted. (SM)

  1. 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

  2. Mutational analysis of Bloom helicase.

    Science.gov (United States)

    Xi, Xu Guang

    2010-01-01

    DNA helicases are biomolecular motors that convert the chemical energy derived from the hydrolysis of nucleotide triphosphate (usually ATP) into mechanical energy to unwind double-stranded DNA. The unwinding of double-stranded DNA is an essential process for DNA replication, repair, recombination, and transcription. Mutations in human RecQ helicases result in inherent human disease including Bloom's syndrome, Werner's syndrome, and Rothmund-Thomson syndrome. Bloom's syndrome (BS) is a rare human autosomal recessive disorder characterized by a strong predisposition to a wide range of cancers commonly affecting the general population. In order to understand the molecular basis of BS pathology and the mechanism underlying the function of Bloom helicase, we have analyzed BS-causing missense mutations by a combination of structural modeling, site-directed mutagenesis, and biochemical and biophysical approaches. Here, we describe the methods and protocols for measuring ATPase, ATP and DNA binding, DNA strand annealing, and DNA unwinding activities of Bloom protein and its mutant variants. These approaches should be applicable and useful for studying other helicases.

  3. Application of Multispectral and Hyperspectral Remote Sensing For Detection of Freshwater Harmful Algal Blooms

    Science.gov (United States)

    Kudela, R. M.; Accorsi, E.; Austerberry, D.; Palacios, S. L.

    2013-12-01

    Freshwater Cyanobacterial Harmful algal blooms (CHABs) represent a pressing and apparently increasing threat to both human and environmental health. In California, toxin producing blooms of several species, including Aphanizomenon, Microcystis, Lyngbya, and Anabaena are common; toxins from these blooms have been linked to impaired drinking water, domestic and wild animal deaths, and increasing evidence for toxin transfer to coastal marine environments, including the death of several California sea otters, a threatened marine species. California scientists and managers are under increasing pressure to identify and mitigate these potentially toxic blooms, but point-source measurements and grab samples have been less than effective. There is increasing awareness that these toxic events are both spatially widespread and ephememeral, leading to the need for better monitoring methods applicable to large spatial and temporal scales. Based on monitoring in several California water bodies, it appears that Aphanizomenon blooms frequently precede dangerous levels of toxins from Microcystis. We are exploring new detection methods for identifying CHABs and potentially distinguishing between blooms of the harmful cyanobacteria Aphanizomenon and Microcystis using remote sensing reflectance from a variety of airborne and satellite sensors. We suggest that Aphanizomenon blooms could potentially be used as an early warning of more highly toxic subsequent blooms, and that these methods, combined with better toxin monitoring, can lead to improved understanding and prediction of CHABs by pinpointing problematic watersheds.

  4. Establishing a connection between high-power pulsars and very-high-energy gamma-ray sources

    CERN Document Server

    Carrigan, S; Hofmann, W; Kosack, K; Lohse, T; Reimer, O

    2007-01-01

    In the very-high-energy (VHE) gamma-ray wave band, pulsar wind nebulae (PWNe) represent to date the most populous class of Galactic sources. Nevertheless, the details of the energy conversion mechanisms in the vicinity of pulsars are not well understood, nor is it known which pulsars are able to drive PWNe and emit high-energy radiation. In this paper we present a systematic study of a connection between pulsars and VHE gamma-ray sources based on a deep survey of the inner Galactic plane conducted with the High Energy Stereoscopic System (H.E.S.S.). We find clear evidence that pulsars with large spin-down energy flux are associated with VHE gamma-ray sources. This implies that these pulsars emit on the order of 1% of their spin-down energy as TeV gamma-rays.

  5. Dynamic imaging of coherent sources reveals different network connectivity underlying the generation and perpetuation of epileptic seizures.

    Directory of Open Access Journals (Sweden)

    Lydia Elshoff

    Full Text Available The concept of focal epilepsies includes a seizure origin in brain regions with hyper synchronous activity (epileptogenic zone and seizure onset zone and a complex epileptic network of different brain areas involved in the generation, propagation, and modulation of seizures. The purpose of this work was to study functional and effective connectivity between regions involved in networks of epileptic seizures. The beginning and middle part of focal seizures from ictal surface EEG data were analyzed using dynamic imaging of coherent sources (DICS, an inverse solution in the frequency domain which describes neuronal networks and coherences of oscillatory brain activities. The information flow (effective connectivity between coherent sources was investigated using the renormalized partial directed coherence (RPDC method. In 8/11 patients, the first and second source of epileptic activity as found by DICS were concordant with the operative resection site; these patients became seizure free after epilepsy surgery. In the remaining 3 patients, the results of DICS / RPDC calculations and the resection site were discordant; these patients had a poorer post-operative outcome. The first sources as found by DICS were located predominantly in cortical structures; subsequent sources included some subcortical structures: thalamus, Nucl. Subthalamicus and cerebellum. DICS seems to be a powerful tool to define the seizure onset zone and the epileptic networks involved. Seizure generation seems to be related to the propagation of epileptic activity from the primary source in the seizure onset zone, and maintenance of seizures is attributed to the perpetuation of epileptic activity between nodes in the epileptic network. Despite of these promising results, this proof of principle study needs further confirmation prior to the use of the described methods in the clinical praxis.

  6. Possibilities by using a self-commutated voltage source inverter connected to a weak grid in wind parks

    Energy Technology Data Exchange (ETDEWEB)

    Svensson, Jan [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Electric Power Engineering

    1996-12-01

    In this paper the hybrid wind farm connected to a weak grid is investigated. By combining different electrical wind power plant systems a cost-efficient solution is obtained. The point of common connection voltage level can be controlled by injecting reactive power from a phase-compensating capacitor battery and a voltage source inverter (VSI). If the short-circuit impedance ratio is lower than 1, the demanded reactive power injection to keep the voltage at nominal level is unrealistic. For short-circuit impedance ratios of 2 or higher the demanded reactive power level is acceptable. When using both induction generators and thyristor inverters the reactive power injector VSI size should be about 0.2 pu. If the hybrid farm consists of THYs, IGs and VSIs and the active power is equally shared between the systems, the VSI had to be scaled up by 5% to handle both active and reactive power. 7 refs, 10 figs, 2 tabs

  7. Resonance Damping Techniques for Grid-Connected Voltage Source Converters with LCL filters – A Review

    DEFF Research Database (Denmark)

    Zhang, Chi; Dragicevic, Tomislav; Vasquez, Juan Carlos;

    2014-01-01

    LCL filters play an important role in grid-connected converters when trying to reduce switching-frequency ripple currents injected into the grid. Besides, their small size and low cost make them attractive for many practical applications. However, the LCL filter is a third-order system, which...... presents a resonance peak frequency. Oscillation will occur in the control loop in high frequency ranges, especially in current loop in double-loops controlled converters. In order to solve this, many strategies have been proposed to damp resonance, including passive and active methods. This paper makes...

  8. Simulation of Five Phase Voltage Source Inverter with Different Excitation for Star Connected Load

    Directory of Open Access Journals (Sweden)

    M.A Inayathullaah

    2014-07-01

    Full Text Available In order to reduce the torque ripple and harmonics for smooth operation of the machine and to reduce the amount of heat generated the motor has to be supplied with multi phase supply greater than three phase supply. Selection of even number of phases should be avoided, because it decreases the performance of the motor as poles coincide with each other. So, Five Phase Supply is preferred. A five phase five leg 10 switch inverter fed five phase star connected load operating with five different excitation is simulated and compared with that of three phase conventional inverter.

  9. Trophic connectivity and basal food sources sustaining tropical aquatic consumers along a mangrove to ocean gradient

    Science.gov (United States)

    Claudino, Marlucy Coelho; Pessanha, André Luiz Machado; Araújo, Francisco Gerson; Garcia, Alexandre Miranda

    2015-12-01

    Variations in the relative importance of autotrophic sources to aquatic consumers along environmental gradients and the trophic role of mangrove-derived detritus to marine coastal food webs are still poorly investigated in tropical systems. In this study, we employed stable isotope analyses to investigate the relative importance of basal food sources to macroconsumers (decapod crustaceans and fishes) in a tropical estuary along an environmental gradient extending from the mangroves to the ocean. Additionally, we evaluated the 'outwelling hypothesis', which hypothesizes that mangrove-derived detritus exported to the adjacent marine area is a food source for marine macroconsumers at open and reef-protected sandy beaches. Primary producers and macroconsumers (62 and 214 samples, respectively) were collected at five locations across the main longitudinal axis of the Mamanguape estuary, a tropical Southwestern Atlantic estuary. There were marked shifts in carbon and nitrogen isotope values for both food sources and consumers along the estuarine-marine gradient, and the mixing model results revealed similar patterns of assimilation of basal food sources by decapod crustaceans and fishes. In the inner section of the estuary, consumers tended to assimilated nutrients derived mainly from mangrove and macroalgae, whereas nearer the mouth of the estuary and in the adjacent marine area they assimilated nutrients derived mainly from macroalgae, seagrass and organic matter in the sediment (SOM). These findings support the hypothesis that the relative importance of basal food sources to macroconsumers in this tropical estuarine system reflects the dominant autochthonous primary production at each location. In contrast, our results did not support the outwelling hypothesis that mangrove-originated detritus, in the form of senescent mangrove leaves, makes a significant contribution as a primary source of carbon to high-order consumers inhabiting adjacent ocean sandy beaches.

  10. Blooming Seas West of Ireland

    Science.gov (United States)

    2007-01-01

    For several weeks in May and early June, daily satellite images of the North Atlantic Ocean west of Ireland have captured partial glimpses of luxuriant blooms of microscopic marine plants between patches of clouds. On June 4, 2007, the skies over the ocean cleared, displaying the sea's spring bloom in brilliant color. A bright blue bloom stretches north from the Mouth of the River Shannon and tapers off like a plume of blue smoke north of Clare Island. (In the large image, a second bloom is visible to the north, wrapping around County Donegal, on the island's northwestern tip.) The image was captured by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Terra satellite. Cold, nutrient-stocked water often wells up to the surface from the deeper ocean along coastal shelves and at the edges of ocean currents. When it does, it delivers a boost of nutrients that fuel large blooms of single-celled plants collectively known as phytoplankton. The plants are the foundation of the marine food web, and their proliferation in this area of the North Atlantic explains why the waters of western Ireland support myriad fisheries and populations of large mammals like seals, whales, and dolphins. Like plants on land, phytoplankton make their food through photosynthesis, harnessing sunlight for energy using chlorophyll and other light-capturing pigments. The pigments change the way light reflects off the surface water, appearing as colorful swirls of turquoise and green against the darker blue of the ocean. Though individually tiny, collectively these plants play a big role in Earth's carbon and climate cycles; worldwide, they remove about as much carbon dioxide from the atmosphere during photosynthesis as land plants do. Satellites are the only way to map the occurrence of phytoplankton blooms across the global oceans on a regular basis. That kind of information is important not only to scientists who model carbon and climate, but also to biologists and fisheries

  11. Grid-Current-Feedback Active Damping for LCL Resonance in Grid-Connected Voltage-Source Converters

    OpenAIRE

    Wang, Xiongfei; Blaabjerg, Frede; Loh, Poh Chiang

    2016-01-01

    This paper investigates active damping of LCL-filter resonance in a grid-connected voltage-source converter with only grid-current feedback control. Basic analysis in the s-domain shows that the proposed damping technique with a negative high-pass filter along its damping path is equivalent to adding a virtual impedance across the grid-side inductance. This added impedance is more precisely represented by a series RL branch in parallel with a negative inductance. The negative inductance helps...

  12. Bloom Filter-Based Secure Data Forwarding in Large-Scale Cyber-Physical Systems

    Directory of Open Access Journals (Sweden)

    Siyu Lin

    2015-01-01

    Full Text Available Cyber-physical systems (CPSs connect with the physical world via communication networks, which significantly increases security risks of CPSs. To secure the sensitive data, secure forwarding is an essential component of CPSs. However, CPSs require high dimensional multiattribute and multilevel security requirements due to the significantly increased system scale and diversity, and hence impose high demand on the secure forwarding information query and storage. To tackle these challenges, we propose a practical secure data forwarding scheme for CPSs. Considering the limited storage capability and computational power of entities, we adopt bloom filter to store the secure forwarding information for each entity, which can achieve well balance between the storage consumption and query delay. Furthermore, a novel link-based bloom filter construction method is designed to reduce false positive rate during bloom filter construction. Finally, the effects of false positive rate on the performance of bloom filter-based secure forwarding with different routing policies are discussed.

  13. An iterative approach for symmetrical and asymmetrical Short-circuit calculations with converter-based connected renewable energy sources

    DEFF Research Database (Denmark)

    Göksu, Ömer; Teodorescu, Remus; Bak-Jensen, Birgitte;

    2012-01-01

    As more renewable energy sources, especially more wind turbines are installed in the power system, analysis of the power system with the renewable energy sources becomes more important. Short-circuit calculation is a well known fault analysis method which is widely used for early stage analysis...... and design purposes and tuning of the network protection equipments. However, due to current controlled power converter-based grid connection of the wind turbines, short-circuit calculation cannot be performed with its current form for networks with power converter-based wind turbines. In this paper......, an iterative approach for short-circuit calculation of networks with power converter-based wind turbines is developed for both symmetrical and asymmetrical short-circuit grid faults. As a contribution to existing solutions, negative sequence current injection from the wind turbines is also taken into account...

  14. Uneven access to safe drinking water for First Nations in Canada: connecting health and place through source water protection.

    Science.gov (United States)

    Patrick, Robert J

    2011-01-01

    Source water protection has gained considerable attention in the water resources literature particularly after several well publicized (non-First Nations) water contamination events in Canada. This short report explores health and place through an examination of access to safe drinking water in a developed country. For First Nations in Canada, safe drinking water remains a serious, albeit under-reported, problem. The incidence of contaminated drinking water is pervasive in many First Nations communities. Attempts to "fix" water quality problems using technology alone have produced only limited success. It will be shown that greater attention to source water protection has potential for both to improve drinking water quality as well as to re-connect health and place for First Nations in Canada.

  15. Modularized multilevel and z-source power converter as renewable energy interface for vehicle and grid-connected applications

    Science.gov (United States)

    Cao, Dong

    Due the energy crisis and increased oil price, renewable energy sources such as photovoltaic panel, wind turbine, or thermoelectric generation module, are used more and more widely for vehicle and grid-connected applications. However, the output of these renewable energy sources varies according to different solar radiation, wind speed, or temperature difference, a power converter interface is required for the vehicle or grid-connected applications. Thermoelectric generation (TEG) module as a renewable energy source for automotive industry is becoming very popular recently. Because of the inherent characteristics of TEG modules, a low input voltage, high input current and high voltage gain dc-dc converters are needed for the automotive load. Traditional high voltage gain dc-dc converters are not suitable for automotive application in terms of size and high temperature operation. Switched-capacitor dc-dc converters have to be used for this application. However, high voltage spike and EMI problems exist in traditional switched-capacitor dc-dc converters. Huge capacitor banks have to be utilized to reduce the voltage ripple and achieve high efficiency. A series of zero current switching (ZCS) or zero voltage switching switched-capacitor dc-dc converters have been proposed to overcome the aforementioned problems of the traditional switched-capacitor dc-dc converters. By using the proposed soft-switching strategy, high voltage spike is reduced, high EMI noise is restricted, and the huge capacitor bank is eliminated. High efficiency, high power density and high temperature switched-capacitor dc-dc converters could be made for the TEG interface in vehicle applications. Several prototypes have been made to validate the proposed circuit and confirm the circuit operation. In order to apply PV panel for grid-connected application, a low cost dc-ac inverter interface is required. From the use of transformer and safety concern, two different solutions can be implemented, non

  16. The death of FRII radio sources and their connection with radio relics

    CERN Document Server

    Kaiser, C R; Kaiser, Christian R.; Cotter, Garret

    2002-01-01

    Radio relic sources in galaxy clusters are often described as the remnants of powerful radio galaxies. Here we develop a model for the evolution of such relics after the jets cease to supply energy to the lobes. This includes the treatment of a relic overpressured with respect to its gaseous surroundings even after the jets switch off. We also determine the radio emission of relics for a large variety of assumptions. We take into account the evolution of the strength of the magnetic field during the phase of relativistic particle injection into the lobes. The resulting spectra show mild steepening at around 1 GHz but avoid any exponential spectral cut-offs. The model calculations are used to fit the observed spectra of six radio relics. The quality of the fits is excellent for {\\it all} models discussed. Unfortunately, this implies that it is virtually impossible to determine any of the important source parameters from the observed radio emission alone.

  17. Solar wind interaction with the Reiner Gamma crustal magnetic anomaly: Connecting source magnetization to surface weathering

    Science.gov (United States)

    Poppe, Andrew R.; Fatemi, Shahab; Garrick-Bethell, Ian; Hemingway, Doug; Holmström, Mats

    2016-03-01

    Remanent magnetization has long been known to exist in the lunar crust, yet both the detailed topology and ultimate origin(s) of these fields remains uncertain. Some crustal magnetic fields coincide with surface albedo anomalies, known as lunar swirls, which are thought to be formed by differential surface weathering of the regolith underlying crustal fields due to deflection of incident solar wind protons. Here, we present results from a three-dimensional, self-consistent, plasma hybrid model of the solar wind interaction with two different possible source magnetizations for the Reiner Gamma anomaly. We characterize the plasma interaction with these fields and the resulting spatial distribution of charged-particle weathering of the surface and compare these results to optical albedo measurements of Reiner Gamma. The model results constrain the proposed source magnetizations for Reiner Gamma and suggest that vertical crustal magnetic fields are required to produce the observed "dark lanes."

  18. Grid Connected Fuel Cell Powered System Using Cascaded Quasi Z Source Network

    Directory of Open Access Journals (Sweden)

    N.Pavithradevi

    2013-06-01

    Full Text Available This paper presents a cascaded quasi-Z-source network based step up DC/DC converter for fuel powered system reduces the component stresses and size of the converter. This network provides voltage boost and buck functions in single stage without any additional switches by the introduction of special switching strategy. Presence of this strategy provides continuous input current on the primary side of the inverter. A voltage doubler is designed for increasing the transformer secondary side voltage. To provide the stable output voltage under the condition of changing input voltage a closed loop response of PI controller is designed. However with the response of PI controller the VDR output is not stable. To stabilize the VDR output ANN technique is used. To maintain the grid voltage and current magnitude at constant value a three phase average model based voltage source inverter is designed. The cascaded quasi-Z-source network based fuel cell powered system is analyzed by Matlab Simulink environment.

  19. A Battery-less Grid Connected Photovoltaic Power generation using Five-Level Common-Emitter Current-Source Inverter

    Directory of Open Access Journals (Sweden)

    Suroso Suroso

    2014-12-01

    Full Text Available Renewable power generation using photovoltaic is very interesting to be developed to deal with the problems of conventional energy sources and environmental issues. The photovoltaic power generation can operate both in stand-alone and grid-connected operations. This paper presents an application of the five-level common-emitter current-source inverter (CE-CSI for grid connected photovoltaic system without batteries as energy storage system. In the proposed system, the five-level CE-CSI works generating a sinusoidal output current from photovoltaic system to be injected into the power grid. The transformer is used in the system to step-down the grid voltage to meet the voltage level of the photovoltaic system, and also works as a galvanic insulation between the power grid and the inverter system. Two conditions of the power grid voltage, i.e. a pure sinusoidal and a distorted power grid, are tested through computer simulation using PSIM software. Furthermore, experimental test result of the five-level inverter is also presented. The test results show that the five-level CE-CSI works well injecting a sinusoidal current into the power grid with low harmonic contents, and with unity power factor operation. The results also show that the distorted grid voltage affects the harmonic contents of the current injected by the inverter.

  20. 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

    Selective grazing of a calanoid copepod Temora longicornis was measured during different stages of a Phaeocystis globosa bloom, in order to reveal (1) if T longicornis feeds on single cells and/or colonies of P. globosa in the presence of alternative food sources, (2) if copepod food selection...... 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...... with highest proportional ingestion of heterotrophic organisms, but was not seriously reduced even during the peak of the bloom. We conclude that P globosa blooms should not threaten survival of copepod populations, but the population recruitment may depend on the type (and concentration) of the dominant...

  1. MERUNUT PEMAHAMAN TAKSONOMI BLOOM: SUATU KONTEMPLASI FILOSOFIS

    OpenAIRE

    Dominikus Tulasi

    2010-01-01

    This article would like to share the use of Bloom's taxonomy as a cognitive framework for teaching-learning process to undertake the way student-centered learning. Related to the curriculum based competence in excellent education, the abstract cognitive in applying Blooms taxonomy is so called scaffolding. We know the taxonomy Bloom is a six-level classification system that uses observed student behavior to infer and absorb the level of cognitive achievement domain. This article surveys think...

  2. Massive phytoplankton blooms under Arctic sea ice.

    Science.gov (United States)

    Arrigo, Kevin R; Perovich, Donald K; Pickart, Robert S; Brown, Zachary W; van Dijken, Gert L; Lowry, Kate E; Mills, Matthew M; Palmer, Molly A; Balch, William M; Bahr, Frank; Bates, Nicholas R; Benitez-Nelson, Claudia; Bowler, Bruce; Brownlee, Emily; Ehn, Jens K; Frey, Karen E; Garley, Rebecca; Laney, Samuel R; Lubelczyk, Laura; Mathis, Jeremy; Matsuoka, Atsushi; Mitchell, B Greg; Moore, G W K; Ortega-Retuerta, Eva; Pal, Sharmila; Polashenski, Chris M; Reynolds, Rick A; Schieber, Brian; Sosik, Heidi M; Stephens, Michael; Swift, James H

    2012-06-15

    Phytoplankton blooms over Arctic Ocean continental shelves are thought to be restricted to waters free of sea ice. Here, we document a massive phytoplankton bloom beneath fully consolidated pack ice far from the ice edge in the Chukchi Sea, where light transmission has increased in recent decades because of thinning ice cover and proliferation of melt ponds. The bloom was characterized by high diatom biomass and rates of growth and primary production. Evidence suggests that under-ice phytoplankton blooms may be more widespread over nutrient-rich Arctic continental shelves and that satellite-based estimates of annual primary production in these waters may be underestimated by up to 10-fold.

  3. Synchronization of grid-connected renewable energy sources under highly distorted voltages and unbalanced grid faults

    DEFF Research Database (Denmark)

    Hadjidemetriou, Lenos; Kyriakides, Elias; Blaabjerg, Frede

    2013-01-01

    renewable energy systems. Therefore, the performance of the new PLL can increase the quality of the injected power under abnormal conditions and in addition enable the renewable energy systems to provide the appropriate support to the grid under balanced and unbalanced grid faults.......Renewable energy sources require accurate and appropriate performance not only under normal grid operation but also under abnormal and faulty grid conditions according to the modern grid codes. This paper proposes a novel phase-locked loop algorithm (MSHDC-PLL), which can enable the fast...... and dynamic synchronization of the interconnected renewable energy system under unbalanced grid faults and under highly harmonic distorted voltage. The outstanding performance of the suggested PLL is achieved by implementing an innovative multi-sequence/harmonic decoupling cell in order to dynamically cancel...

  4. Improved direct power control of a grid-connected voltage source converter during network unbalance

    Institute of Scientific and Technical Information of China (English)

    Peng ZHOU; Wei ZHANG; Yi-kang HE; Rong ZENG

    2010-01-01

    This paper deals with an improved direct power control(DPC)strategy for the pulse width modulation(PWM)voltage source converter(VSC)under unbalanced grid voltage conditions.In order to provide enhanced control performance for the VSC,the resonant controllers tuned at the double grid frequency are applied in the DPC design to eliminate the power pulsations and dc link voltage ripples produced by the transient unbalanced grid faults.In this way,the output power and dc link voltage of the VSC can be directly regulated without positive and negative sequential decomposition.As a result,and as has been verified by experiment,the proposed method can provide fast dynamic response with easy implementation.

  5. Optical counterpart positions of extragalactic radio sources and connecting optical and radio reference frames

    Science.gov (United States)

    Aslan, Z.; Gumerov, R.; Jin, W.; Khamitov, I.; Maigurova, N.; Pinigin, G.; Tang, Z.; Wang, S.

    2010-01-01

    We discuss the results of an investigation of astrometric positions of extragalactic radio sources from a list for the International Celestial Reference Frame. About 300 fields around extragalactic radio sources were observed during the years 2000-2003. The observations were performed mainly using two telescopes equipped with CCD cameras at TUG, Turkey (Russian-Turkish Telescope - RTT150) and at YAO (1 m telescope), (Kunming, China). The mean accuracies of the measured positions are 38 mas in right ascension and 35 mas in declination. A comparison between the measured optical positions determined using the UCAC2 catalog and the radio positions from the current ICRF shows that the overall optical-minus- radio offsets are -4 and +15 mas for right ascension and declination, respectively. The formal internal errors of these mean offsets are 4 mas. The results of optical positions with respect to the reference catalogue 2MASS are also given. A search for a relation between optical and radio reference frames indicates that the orientation angles are near zero within their accuracy of about 5 mas. The link accuracy becomes 3 mas when our observations are combined with other studies. Tables 2 and 3 giving the positions are only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/510/A10Present address: İstanbul Kültür University, Ataköy Yerleşkesi, 34156 Istanbul, Turkey

  6. The improved Z source grid-connected inverter%改进型Z源并网逆变器

    Institute of Scientific and Technical Information of China (English)

    侯世英; 黄哲; 肖旭; 曾鹏; 陈剑飞

    2012-01-01

    针对传统Z源并网逆变器升压能力有限、启动冲击较为严重、输入电流断续造成直流电压利用率低等方面的不足,对传统的阻抗网络进行改进,提出一种改进型Z源并网逆变器拓扑.该拓扑在传统的阻抗网络的基础上增加一个有源开关及电感,与传统阻抗网络中的输入二极管在前级构成一个等效Boost电路,提高了传统Z源逆变器的升压能力,电感的加入也限制了启动冲击电流,并保证了输入电流的连续.在理论分析的基础上,对基于改进型Z源逆变器的单相并网系统进行了仿真及实验研究,结果均表明该拓扑能够以实现单位功率因素并网,且启动过程平缓,输出电能质量好,系统效率高,验证了该拓扑的可行性及性能的优越性.%As for the traditional Z-source inverter has the disadvantages of low boost capacity, serious start impact, the input current intermittent and DC voltage low utilization deficiencies, this paper optimizes the impedance network of the traditional Z-source inverter and proposes a simplified Z-source grid-connected inverter topology. By adding an active switch and inductor, the topology constituted an equivalent Boost circuit in the former class with the input diode in traditional impedance network, so the boost capacity of traditional Z-source inverter was improved; the startup impact current was limited and the input current was maintained continuously. Based on the theoretical analysis, the simulation and experiment on single-phase grid-connected systems with the improved Z-source inverter have been done, and the simulation and experimental results verify the superiority and the feasibility of the topology.

  7. 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.

  8. Bloom syndrome with lung involvement

    Directory of Open Access Journals (Sweden)

    Nair Girija

    2009-01-01

    Full Text Available We report a case of a 24-year old male presented with cough and breathlessness with diabetes mellitus and diagnosed as a case of bloom syndrome. He was a product of consanguineous marriage, having short stature, dolicocephaly, polydactyly, prominent nose with telangiectasia face. The respiratory system examination revealed bilateral coarse crepitations and wheezes and the chest X-ray revealed emphysema with right middle zone inhomogenous opacity. Also, CT thorax examination revealed bilateral cystic bronchiectasis with bronchiolitis obliterans. Bloom′s syndrome was diagnosed on the basis of clinical features.

  9. Experimental Research of Variable Operating Performance on Water Source Multi-Connected Air-Conditioning System with Digital Scroll Compressor

    Directory of Open Access Journals (Sweden)

    Xingwang Zhu

    2013-05-01

    Full Text Available In this study, we study the water source heat pump and digital scroll compressor and experimentally in the multi-connected air-conditioning system. Variable performance is developed when the unit operates in refrigerating and heating mode. The maximum of refrigerating capacity is 36519.95W when inlet water temperature of the condenser is 30°C and dry-bulb temperature of indoor air is 32°C, at the same time the maximum of EER is 4.33 when inlet water temperature of the condenser is 20°C and dry-bulb temperature of indoor air is 27°C. The unit operates in heating mode, the maximum of heating capacity and EER is 33275.73W and 3.86 when inlet water temperature of the condenser is 30°C and dry-bulb temperature of indoor air is 20°C.

  10. Connecting Hundreds of Oceanographic Data Sources from 35 Countries in and around Europe into a Big Data Network

    Science.gov (United States)

    De Bruin, T.

    2014-12-01

    Until some years ago, oceanographic data in Europe were scattered across dozens of data centres and hundreds of government agencies, research institutes and university groups. As a consequence, it was impossible to get an overview of available data and very difficult to get access to the data. And even if one managed to get access, data were difficult to use because the data came in different formats and were of varying quality.All these issues were successfully addressed in a series of projects culminating in the current SeaDataNet-project. The resulting and operational SeaDataNet infrastructure now connects hundreds of data sources from 35 countries in and around Europe. It was designed to provide a central overview of available data as well as direct access to a distributed system of online data sources. When data are being transferred to the user, the data are converted into a standard format, chosen by the user. Through a joint activity with the MyOcean project, all data within the SeaDataNet infrastructure have been quality controlled.The SeaDataNet infrastructure now offers many possibilities in support of Europe's 'blue economy'. It forms the backbone for the projects under the umbrella of the European Marine Observation and Data Network or EMODNet. The EMODNet projects produce a series of dataproducts on all aspects of the European marine environment. The data for these dataproducts are provided using the SeaDataNet infrastructure.This presentation describes the principles of the SeaDataNet infrastructure and how it connects those hundreds of data sources in Europe. It will explain the strong link, but also the differences, with the MyOcean project and will go on to introduce the EMODNet-programme and -projects as an example of what can be done if one has achieved uniform access to a distributed system of hundreds of data sources. Finally, the presentation will also address the long-term sustainability of the chosen approach.

  11. Algal blooms and Membrane Based Desalination Technology

    NARCIS (Netherlands)

    Villacorte, L.O.

    2014-01-01

    Seawater desalination is rapidly growing in terms of installed capacity (~80 million m3/day in 2013), plant size and global application. An emerging threat to this technology is the seasonal proliferation of microscopic algae in seawater known as algal blooms. Such blooms have caused operational pro

  12. Summer heatwaves promote blooms of harmful cyanobacteria

    NARCIS (Netherlands)

    Joehnk, K.D; Huisman, J.; Sharples, J.; Sommeijer, B.P.; 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 experi

  13. Bloom syndrome in an Indian child.

    Science.gov (United States)

    Inamadar, Arun C; Palit, Aparna

    2005-01-01

    A girl presented with severely stunted growth, photosensitivity, and a characteristic facies. Cytogenetic studies were suggestive of Bloom syndrome. This disorder has not been previously documented in the literature in an Indian child. Minor variations in characteristics in this patient have been highlighted. Cytogenetically, she was found to be a low sister chromatid exchange mosaicism of Bloom syndrome.

  14. Nitrogen deposition fuels harmful algal blooms in the East China Sea

    Science.gov (United States)

    Mackey, K. R.; Kavanaugh, M.; Chien, C. T.; Chen, Y.; Glover, D. M.; Paytan, A.

    2015-12-01

    Chinese marginal seas support vast fisheries and vital economies, but their productivity is threatened by eutrophication and increasing harmful algal blooms (HABs). Here we provide direct experimental evidence that aerosol enrichment shifts seawater chemistry by increasing the ratio of N to phosphorus (N:P) and supports the growth of bloom-forming phytoplankton in the East China Sea. We use a combination of field-based aerosol addition incubation experiments, along with ocean color data on blooms dominated by different taxa to show that HAB forming dinoflagellates are particularly responsive to aerosol inputs. Moreover, we show that the effect of N deposition is strongest in offshore waters further from the Yangtze River outflow, consistent with the large anthropogenic flux of N from this source. This study shows the potential for aerosols to control N:P ratios in offshore waters and to shape the phytoplankton community, contributing to the success of bloom-forming organisms.

  15. Environmental characteristics of annual pico/nanophytoplankton blooms along the Qinhuangdao coast

    Science.gov (United States)

    Cao, Xihua; Yu, Zhiming; Wu, Zaixing; Cheng, Fangjin; He, Liyan; Yuan, Yongquan; Song, Xiuxian; Zhang, Jianle; Zhang, Yongfeng; Zhang, Wanlei

    2017-03-01

    Blooms of some pico/nanophytoplankton have occurred frequently along the Qinhuangdao coast since 2009, and it is necessary to identify the critical environmental factors inducing them. In this study, variations in the physical and nutrient characteristics of the seawater were analyzed following the development of local blooms in 2013. The local environmental characteristics were also compared with those of the Changjiang River estuary, China, and the Long Island estuaries in the USA, which are also prone to blooms of special algal species. In Qinhuangdao the local water temperature varied seasonally and rose above 15°C in 2013 early summer, coincident with the water discoloration. The salinity was more than 28 with a variation range of <3 throughout the year. Our results suggest that the physical conditions of the Qinhuangdao coastal area were suitable for the explosive proliferation of certain pico/nanophytoplankton, e.g. Aureococcus anophagefferens. The water supporting the bloom was not in a condition of serious eutrophication, but there were relatively high concentrations of reduced nitrogen (especially ammonium), which acted as an important nitrogen source for the pico/nanophytoplankton bloom. There was also a large gap between total nitrogen (TN) and dissolved inorganic nitrogen (DIN). Although the phosphate concentration was relatively low, there was no evidence of phosphorus limitation to the growth of pico/nanophytoplankton during bloom events.

  16. On the horizontal distribution of algal-bloom in Chaohu Lake and its formation process

    Science.gov (United States)

    Chen, Yuan-Ying; Liu, Qing-Quan

    2014-10-01

    Based on the remote sensing images of algae, the present work analyzes the horizontal distribution characteristics of algal blooms in Chaohu Lake, China, which also reveals the frequency of algal blooms under different wind directions. Further, an unstructured-grid, three-dimensional finite-volume coastal ocean model (FVCOM) is applied to investigate the wind-induced currents and the transport process to explain the reason why algal blooms occur at the detected places. We first deduce the primary distribution of biomass from overlaid satellite images, and explain the formation mechanism by analyzing the pollution sources, and simulating the flow field and transportation process under prevailing wind over Chaohu Lake. And then, we consider the adjustment action of the wind on the corresponding day and develop a two-time scale approach to describe the whole formation process of algae horizontal distribution in Chaohu Lake. That is, on the longer time scale, i.e., during bloom season, prevailing wind determines the primary distribution of biomass by inducing the characteristic flow field; on the shorter time scale, i.e., on the day when bloom occurs, the wind force adjusts the primary distribution of biomass to form the final distribution of algal bloom.

  17. A rare Uroglena bloom in Beaver Lake, Arkansas, spring 2015

    Science.gov (United States)

    Green, William R.; Hufhines, Brad

    2017-01-01

    A combination of factors triggered a Uroglena volvox bloom and taste and odor event in Beaver Lake, a water-supply reservoir in northwest Arkansas, in late April 2015. Factors contributing to the bloom included increased rainfall and runoff containing increased concentrations of dissolved organic carbon, followed by a stable pool, low nutrient concentrations, and an expansion of lake surface area and littoral zone. This was the first time U. volvox was identified in Beaver Lake and the first time it was recognized as a source of taste and odor. Routine water quality samples happened to be collected by the US Geological Survey and the Beaver Water District throughout the reservoir during the bloom—. Higher than normal rainfall in March 2015 increased the pool elevation in Beaver Lake by 2.3 m (by early April), increased the surface area by 10%, and increased the littoral zone by 1214 ha; these conditions persisted for 38 days, resulting from flood water being retained behind the dam. Monitoring programs that cover a wide range of reservoir features, including dissolved organic carbon, zooplankton, and phytoplankton, are valuable in explaining unusual events such as this Uroglena bloom.

  18. Algal blooms and Membrane Based Desalination Technology

    OpenAIRE

    Villacorte, L.O.

    2014-01-01

    Seawater desalination is rapidly growing in terms of installed capacity (~80 million m3/day in 2013), plant size and global application. An emerging threat to this technology is the seasonal proliferation of microscopic algae in seawater known as algal blooms. Such blooms have caused operational problems in seawater reverse osmosis (SWRO) plants due to clogging and poor effluent quality of the pre-treatment system which eventually forced the shutdown of the plant to avoid irreversible fouling...

  19. Listening to the sound of flower blooming

    Institute of Scientific and Technical Information of China (English)

    YAN; Wei-fang

    2015-01-01

    The most beautiful thing in our life is the first glance,and the most beautiful point of fireworks is its evanescent bloom.Thing’s beautiful is usually due to its evanescent exist.It might exist shortly but in our mind for a long time.As for me,the most beautiful thing is to listen to the sound of flower blooming.

  20. Bloom's taxonomy of cognitive learning objectives.

    Science.gov (United States)

    Adams, Nancy E

    2015-07-01

    Information professionals who train or instruct others can use Bloom's taxonomy to write learning objectives that describe the skills and abilities that they desire their learners to master and demonstrate. Bloom's taxonomy differentiates between cognitive skill levels and calls attention to learning objectives that require higher levels of cognitive skills and, therefore, lead to deeper learning and transfer of knowledge and skills to a greater variety of tasks and contexts.

  1. Bloom's Taxonomy and Training in Programming Style

    OpenAIRE

    Teodosi TEODOSIEV

    2013-01-01

    Report published in the Proceedings of the National Conference on "Education in the Information Society", Plovdiv, May, 2013 The presented work is using Bloom's taxonomy to set the goals of teaching programming. Here are shown the elements of programming style, in which you can teach novices. Elements of programming style are at different levels of Bloom's pyramid. Association for the Development of the Information Society, Institute of Mathematics and Informatics Bulgarian Academ...

  2. Rainfall-enhanced blooming in typhoon wakes

    Science.gov (United States)

    Lin, Y.-C.; Oey, L.-Y.

    2016-08-01

    Strong phytoplankton blooming in tropical-cyclone (TC) wakes over the oligotrophic oceans potentially contributes to long-term changes in global biogeochemical cycles. Yet blooming has traditionally been discussed using anecdotal events and its biophysical mechanics remain poorly understood. Here we identify dominant blooming patterns using 16 years of ocean-color data in the wakes of 141 typhoons in western North Pacific. We observe right-side asymmetric blooming shortly after the storms, attributed previously to sub-mesoscale re-stratification, but thereafter a left-side asymmetry which coincides with the left-side preference in rainfall due to the large-scale wind shear. Biophysical model experiments and observations demonstrate that heavier rainfall freshens the near-surface water, leading to stronger stratification, decreased turbulence and enhanced blooming. Our results suggest that rainfall plays a previously unrecognized, critical role in TC-induced blooming, with potentially important implications for global biogeochemical cycles especially in view of the recent and projected increases in TC-intensity that harbingers stronger mixing and heavier rain under the storm.

  3. Biology in Bloom: Implementing Bloom's Taxonomy to Enhance Student Learning in Biology

    Science.gov (United States)

    Crowe, Alison; Dirks, Clarissa; Wenderoth, Mary Pat

    2008-01-01

    We developed the Blooming Biology Tool (BBT), an assessment tool based on Bloom's Taxonomy, to assist science faculty in better aligning their assessments with their teaching activities and to help students enhance their study skills and metacognition. The work presented here shows how assessment tools, such as the BBT, can be used to guide and…

  4. Bloom: A Relationship Visualization Tool for Complex Networks

    Directory of Open Access Journals (Sweden)

    Frank Horsfall

    2010-07-01

    Full Text Available Faced with an ever-increasing capacity to collect and store data, organizations must find a way to make sense of it to their advantage. Methods are required to simplify the data so that it can inform strategic decisions and help solve problems. Visualization tools are becoming increasingly popular since they can display complex relationships in a simple, visual format. This article describes Bloom, a project at Carleton University to develop an open source visualization tool for complex networks and business ecosystems. It provides an overview of the visualization technology used in the project and demonstrates its potential impact through a case study using real-world data.

  5. Biomass decay rates and tissue nutrient loss in bloom and non-bloom-forming macroalgal species

    Science.gov (United States)

    Conover, Jessie; Green, Lindsay A.; Thornber, Carol S.

    2016-09-01

    Macroalgal blooms occur in shallow, low-wave energy environments and are generally dominated by fast-growing ephemeral macroalgae. When macroalgal mats undergo senescence and decompose they can cause oxygen depletion and release nutrients into the surrounding water. There are relatively few studies that examine macroalgal decomposition rates in areas impacted by macroalgal blooms. Understanding the rate of macroalgal bloom decomposition is essential to understanding the impacts of macroalgal blooms following senescence. Here, we examined the biomass, organic content, nitrogen decay rates and δ15N values for five macroalgal species (the bloom-forming Agardhiella subulata, Gracilaria vermiculophylla, Ulva compressa, and Ulva rigida and the non-bloom-forming Fucus vesiculosus) in Narragansett Bay, Rhode Island, U.S.A. using a litterbag design. Bloom-forming macroalgae had similar biomass decay rates (0.34-0.51 k d-1) and decayed significantly faster than non-bloom-forming macroalgae (0.09 k d-1). Biomass decay rates also varied temporally, with a significant positive correlation between biomass decay rate and water temperature for U. rigida. Tissue organic content decreased over time in all species, although A. subulata and G. vermiculophylla displayed significantly higher rates of organic content decay than U. compressa, U. rigida, and F. vesiculosus. Agardhiella subulata had a significantly higher rate of tissue nitrogen decay (0.35 k d-1) than all other species. By contrast, only the δ15N of F. vesiculosus changed significantly over the decay period. Overall, our results indicate that bloom-forming macroalgal species decay more rapidly than non-bloom-forming species.

  6. Phytoplankton Bloom Phenology near Palmer Station Antarctica

    Science.gov (United States)

    Crews, L.; Doney, S. C.; Kavanaugh, M.; Ducklow, H. W.; Schofield, O.; Glover, D. M.

    2015-12-01

    West Antarctic Peninsula (WAP) phytoplankton bloom phenology is coupled to growing season water column stratification precipitated by seasonal warming and the melting of winter sea-ice. Previous studies document declining bloom magnitude over decadal timescales in conjunction with decreasing sea-ice extent and duration in the Northern WAP, but less work has been to done explain the observed inter-annual variability in this region. Here we use a high-resolution in situ time series collected by the Palmer Station Antarctica Long Term Ecological Research program and satellite ocean color imagery to investigate the underlying mechanisms controlling phytoplankton bloom timing and magnitude near Palmer Station. We pair chlorophyll and CTD measurements collected twice per week during the austral summer, 1992—2003, with satellite ocean color and ice fractional cover data to examine bloom development and within-season trends in mixed layer depth. Initial results suggest a possible shift over time with spring/summer blooms occurring earlier in the growing season reflecting earlier sea-ice free conditions. Net phytoplankton accumulation rates are also computed and compared against growth estimates. Our results can be used to develop and validate models of coastal Antarctic primary production that better represent inter-annual primary production variability.

  7. A Matching Transformer-less Inrush Current Suppressor for Transformers Using a Series-Connected Small-Rated Voltage-Source PWM Converter

    Science.gov (United States)

    Yamada, Hiroaki; Tanaka, Toshihiko; Funabiki, Shigeyuki

    This paper proposes a new inrush current suppressor using a series-connected small-rated PWM converter for a transformer. The PWM converter is directly connected in series between the source and transformer without a matching transformer. The inrush phenomena of the matching transformer, thus, can be avoided. The control gain and required-ratings of the series-connected small-rated PWM converter is discussed in detail. The capacity of the dc capacitor of the PWM converter is also discussed considering the active power flows into the PWM converter. The PSCAD/EMTDC is used to verify the validity of the proposed inrush current suppressor. A prototype experimental model is constructed and tested. The experimental results demonstrate that the proposed suppressor can perfectly overcome the inrush phenomena of transformers.

  8. DC-bus voltage control of grid-connected voltage source converter by using space vector modulated direct power control under unbalanced network conditions

    DEFF Research Database (Denmark)

    Xiao, Lei; Huang, Shoudao; Lu, Kaiyuan

    2013-01-01

    Unbalanced grid voltage will cause large dc-bus voltage ripple and introduce high harmonic current components on the grid side. This will severely threaten the safety of the grid-connected voltage source converter (VSC) and consequently, affect the healthy operation condition of the load. In this......Unbalanced grid voltage will cause large dc-bus voltage ripple and introduce high harmonic current components on the grid side. This will severely threaten the safety of the grid-connected voltage source converter (VSC) and consequently, affect the healthy operation condition of the load....... In this study, a new proportional-integral-resonant (PI-RES) controller-based, space vector modulated direct power control topology is proposed to suppress the dc-bus voltage ripple and in the same time, controlling effectively the instantaneous power of the VSC. A special ac reactive power reference component...

  9. DC Bus Control of Back-to-Back Connected Two-Level PWM Rectifier-Five-Level NPC Voltage Source Inverter to Torque Ripple Reduction in Induction Motor

    Directory of Open Access Journals (Sweden)

    Abdelkrim Thameur

    2015-01-01

    Full Text Available This paper proposes a regulation method of back-to-back connected two-level PWM rectifier-five-level Voltage Source Inverter (VSI in order to reduce the torque ripple in induction motor. First part is dedicated to the presentation of the feedback control of two-level PWM rectifier. In the second part, five-level Neutral Point Clamped (NPC voltage source inverter balancing DC bus algorithm is presented. A theoretical analysis with a complete simulation of the system is presented to prove the excellent performance of the proposed technique.

  10. Design of serially connected ammonia-water hybrid absorption-compression heat pumps for district heating with the utilisation of a geothermal heat source

    DEFF Research Database (Denmark)

    Jensen, Jonas Kjær; Ommen, Torben Schmidt; Markussen, Wiebke Brix;

    2016-01-01

    District heating (DH) can reduce the primary energy consumption in urban areas with significant heat demands. The design of a serially connected ammonia-water hybrid absorption-compression heat pump system was investigated for operation in the Greater Copenhagen DH network in Denmark, in order...... to supply 7.2 MW heat at 85 °C utilizing a geothermal heat source at 73 °C. Both the heat source and heat sink experience a large temperature change over the heat transfer process, of which a significant part may be achieved by direct heat exchange. First a generic study with a simple representation...

  11. AN OVERVIEW ON BLOOM'S REVISED TAKSONOMY

    OpenAIRE

    TUTKUN, Ömer Faruk

    2013-01-01

    In this study, the main purpose is to present the main frame of revised version in 2001 of Bloom's taxonomy that has been accepted extensively in our country since 1956 as well as around the world. In accordance with this purpose, in the study, answers have been searched to these questions: 1- The rise of the original Bloom's taxonomy and what are the key features of? 2- What are the reasons for renewal of original taxonomy? 3- What kind of arrangements has been made in revised taxonomy? 4- W...

  12. Temporal and spatial characteristics of harmful algal blooms in Qingdao Waters, China

    Science.gov (United States)

    Yuan, Yongquan; Yu, Zhiming; Song, Xiuxian; Cao, Xihua

    2016-05-01

    Qingdao waters, including both the semi-enclosed Jiaozhou Bay (JB) and the adjacent water out of JB (OJB), have been the areas that are most frequently aff ected by harmful algal blooms (HABs) in the western Yellow Sea (west of 124°E). In this research, HAB occurrences in Qingdao waters from 1990 to 2009 were investigated using spatial tools in geographic information system (GIS) and are discussed in terms of their connection to temporal variation. Additionally, the eff ects of each HAB occurrence were further evaluated using a simple model. The calculated results were then visualized using a GIS software to indicate the eff ects of HABs in Qingdao waters during the entire period. As a result, the OJB was proven to be responsible for the frequent HAB occurrences in Qingdao waters after 2000, although JB was traditionally believed to be the principle source of HAB occurrences in Qingdao waters. In addition, increasing nitrogen and N/P structure imbalance were essential for increasing HAB occurrences in Qingdao waters throughout the entire period, especially for the recent HAB occurrences in the OJB. The results of this research would improve the current understanding on HAB occurrences in Qingdao waters, which would benefit HAB monitoring and the implementation of a control strategy in China as well.

  13. Coastal engineering and Harmful Algal Blooms along Alexandria coast, Egypt

    Directory of Open Access Journals (Sweden)

    Amany A. Ismael

    2014-01-01

    The phytoplankton composition and its standing crop became totally different during the two periods. The most important bloom was caused by Micromonas pusilla forming a heavy green tide accompanied by a bloom of Peridinium quinquecorne. Although there were no fish or invertebrate mortality, this bloom caused economic losses to internal tourism. In the absence of any Environmental Assessment, the coastal engineering works increased the harmful algal blooms in Alexandria coastal waters, even after corrective steps were taken to mitigate the harmful effects.

  14. MERUNUT PEMAHAMAN TAKSONOMI BLOOM: SUATU KONTEMPLASI FILOSOFIS

    Directory of Open Access Journals (Sweden)

    Dominikus Tulasi

    2010-09-01

    Full Text Available This article would like to share the use of Bloom's taxonomy as a cognitive framework for teaching-learning process to undertake the way student-centered learning. Related to the curriculum based competence in excellent education, the abstract cognitive in applying Blooms taxonomy is so called scaffolding. We know the taxonomy Bloom is a six-level classification system that uses observed student behavior to infer and absorb the level of cognitive achievement domain. This article surveys thinking within general education and management education, which uses and draws on Bloom's taxonomy, and then describes suggested uses of the taxonomy. The empirical evaluation of its effect on student achievement follows, as do thoughts about ways colleagues might use this tool to empower and motivate students as self-responsible learners in the classroom. The objective is to promote higher order thinking in college students, we understood an effort to learn how to assess critical-thinking skills in an introductory course. It means, we develop a process by which questions are prepared with both content and critical-thinking skills in mind.

  15. Harmful cyanobacterial blooms: causes, consequences, and controls.

    Science.gov (United States)

    Paerl, Hans W; Otten, Timothy G

    2013-05-01

    Cyanobacteria are the Earth's oldest oxygenic photoautotrophs and have had major impacts on shaping its biosphere. Their long evolutionary history (≈ 3.5 by) has enabled them to adapt to geochemical and climatic changes, and more recently anthropogenic modifications of aquatic environments, including nutrient over-enrichment (eutrophication), water diversions, withdrawals, and salinization. Many 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. Bloom-forming cyanobacterial taxa can be harmful from environmental, organismal, and human health perspectives by outcompeting beneficial phytoplankton, depleting oxygen upon bloom senescence, and producing a variety of toxic secondary metabolites (e.g., cyanotoxins). How environmental factors impact cyanotoxin production is the subject of ongoing research, but nutrient (N, P and trace metals) supply rates, light, temperature, oxidative stressors, interactions with other biota (bacteria, viruses and animal grazers), and most likely, the combined effects of these factors are all involved. Accordingly, strategies aimed at controlling and mitigating harmful blooms have focused on manipulating these dynamic factors. The applicability and feasibility of various controls and management approaches is discussed for natural waters and drinking water supplies. Strategies based on physical, chemical, and biological manipulations of specific factors show promise; however, a key underlying approach that should be considered in almost all instances is nutrient (both N and P) input reductions; which have been shown to effectively reduce cyanobacterial biomass, and therefore limit health risks and frequencies of hypoxic events.

  16. Spring bloom onset in the Nordic Seas

    Science.gov (United States)

    Mignot, Alexandre; Ferrari, Raffaele; Mork, Kjell Arne

    2016-06-01

    The North Atlantic spring bloom is a massive annual growth event of marine phytoplankton, tiny free-floating algae that form the base of the ocean's food web and generates a large fraction of the global primary production of organic matter. The conditions that trigger the onset of the spring bloom in the Nordic Seas, at the northern edge of the North Atlantic, are studied using in situ data from six bio-optical floats released north of the Arctic Circle. It is often assumed that spring blooms start as soon as phytoplankton cells daily irradiance is sufficiently abundant that division rates exceed losses. The bio-optical float data instead suggest the tantalizing hypothesis that Nordic Seas blooms start when the photoperiod, the number of daily light hours experienced by phytoplankton, exceeds a critical value, independently of division rates. The photoperiod trigger may have developed at high latitudes where photosynthesis is impossible during polar nights and phytoplankton enters into a dormant stage in winter. While the first accumulation of biomass recorded by the bio-optical floats is consistent with the photoperiod hypothesis, it is possible that some biomass accumulation started before the critical photoperiod but at levels too low to be detected by the fluorometers. More precise observations are needed to test the photoperiod hypothesis.

  17. In the Cells of the 'Bloom Taxonomy'.

    Science.gov (United States)

    Calder, J. R.

    1983-01-01

    The Bloom Taxonomy of Educational Objectives is criticized because its distinctions between cognitive, affective, and psychomotor domains are invalid; its categories are ill-defined and do not denote homogenous types of objectives; its structural base is inconsistent; and it is debatable whether it is a true taxonomy. (IS)

  18. Biology in Bloom: Implementing Bloom's Taxonomy to Enhance Student Learning in Biology

    OpenAIRE

    Crowe, Alison; Dirks, Clarissa; Wenderoth, Mary Pat

    2008-01-01

    We developed the Blooming Biology Tool (BBT), an assessment tool based on Bloom's Taxonomy, to assist science faculty in better aligning their assessments with their teaching activities and to help students enhance their study skills and metacognition. The work presented here shows how assessment tools, such as the BBT, can be used to guide and enhance teaching and student learning in a discipline-specific manner in postsecondary education. The BBT was first designed and extensively tested fo...

  19. T.S. ELIOT'S MISREADING OF SOME LITERARY SOURCES IN THE WASTE LAND

    Directory of Open Access Journals (Sweden)

    Liem Satya Limanta

    2002-01-01

    Full Text Available A poet cannot be a poet at all if he is not connected with all the poetic tradition before him. This is T.S. Eliot's dictum which he stated in Tradition and the Individual Talent and which he practiced in his work The Waste Land. T.S. Eliot showed his relationship with the past through all the quotations and allusions to mythical, literary, and religious works. His reading of those sources according to Paul de Man cannot avoid misreading or misinterpretation. Harold Bloom has tried to build up a theory of misreading, which he prefers to call misprision, especially applied to and done by poets in The Anxiety of Influence. Throughout this article I shall show how T.S. Eliot has applied some of the ways Bloom describes in reading some of the literary sources, and by so doing Eliot has given new meaning to them.

  20. 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

  1. Violence as a source of pleasure or displeasure is associated with specific functional connectivity with the nucleus accumbens

    Directory of Open Access Journals (Sweden)

    Eric C Porges

    2013-08-01

    Full Text Available The appraisal of violent stimuli is dependent on the social context and the perceiver’s individual characteristics. To identify the specific neural circuits involved in the perception of violent videos, forty-nine male participants were scanned with functional MRI while watching video-clips depicting Mixed Martial Arts (MMA and Capoeira as a baseline. Prior to scanning, a self-report measure of pleasure or displeasure when watching MMA was collected. Watching MMA was associated with activation of the anterior insula, brainstem, ventral tegmental area, striatum, medial and lateral prefrontal cortex, orbitofrontal cortex, somatosensory cortex, and supramarginal gyrus. While this pattern of brain activation was not related to participants’ reported experience of pleasure or displeasure, pleasurable ratings of MMA predicted increased functional connectivity seeded in the nucleus accumbens (a structure known to be responsive to anticipating both positive and negative outcomes with the subgenual anterior cingulate cortex and anterior insular cortex (regions involved in positive feelings and visceral somatic representations. Displeasure ratings of MMA were related to increased functional connectivity with regions of the prefrontal cortex and superior parietal lobule, structures implicated in cognitive control and executive attention. These data suggest that functional connectivity is an effective approach to investigate the relationship between subjective feelings of pleasure and pain of neural structures known to respond to both the anticipation of positive and negative outcomes.

  2. 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.

  3. Phosphorus mobility among sediments, water and cyanobacteria enhanced by cyanobacteria blooms in eutrophic Lake Dianchi.

    Science.gov (United States)

    Cao, Xin; Wang, Yiqi; He, Jian; Luo, Xingzhang; Zheng, Zheng

    2016-12-01

    This study was focused on the phosphorus mobility among sediments, water and cyanobacteria in eutrophic Lake Dianchi. Four conditions lake water, water and algae, water and sediments, and three objects together were conducted to investigate the effects of cyanobacteria growth on the migration and transformation of phosphorus. Results showed a persistent correlation between the development of cyanobacterial blooms and the increase of soluble reactive phosphorus (SRP) in the lake water under the condition of three objects together. Time-course assays measuring different forms of phosphorus in sediments indicated that inorganic phosphorus (IP) and NaOH-P were relatively more easier to migrate out of sediment to the water and cyanobacteria. Further studies on phosphorus mobility showed that up to 70.2% of the released phosphorus could be absorbed by cyanobacteria, indicating that sediment is a major source of phosphorus when external loading is reduced. Time-course assays also showed that the development of cyanobacterial blooms promoted an increase in pH and a decrease in the redox potential of the lake water. The structure of the microbial communities in sediments was also significantly changed, revealed a great impaction of cyanobacterial blooms on the microbial communities in sediments, which may contribute to phosphorus release. Our study simulated the cyanobacterial blooms of Lake Dianchi and revealed that the cyanobacterial blooms is a driving force for phosphorus mobility among sediments, water and cyanobacteria. The outbreak of algal blooms caused deterioration in water quality. The P in the sediments represented a significant supply for the growth of cyanobacteria.

  4. Hysteresis Current Controller Based Grid Connected Wind Energy Conversion System for Permanent Magnet Synchronous Generator and Quasi Z-Source Inverter Using Power Quality Improvement

    Directory of Open Access Journals (Sweden)

    E.Rajendran

    2013-10-01

    Full Text Available Wind energy is a leader area of application for variable-speed generators operating on the constant grid frequency. This paper depicts the power quality enhancement in wind power system using permanent magnet synchronous generator (PMSG and Quasi Z-source Inverter. The PMSG is connected to the power network by means of a quasi z-source inverter (qZSI. The PMSG are used by these technologies due to extraordinary characteristics such as a smaller amount weight and volume, superior performance, eradicate the gear box and no need of peripheral power in permanent magnet excitation. The PMSG overcome the induction generator and other generators, because of their splendid performances without take up the grid power. But Induction Generator always needs the grid connectionfor getting power to start. In this paper the quasi Z-source inverter is a present that is a novel topology conjugated from the traditional Z source Inverter. The qZSI inherits all the advantages of the ZSI, that is performs buck-boost, inversion and power control in wind energy conversion system (WECS Moreover, the proposed qZSI the matchless advantages of less component ratings and stable dc current from the source. All over boost control methods are built for the ZSI can be used by the qZSI .This Paper presents hysteresis current control technique for the quasi Z- source inverter.

  5. The effect of environmental parameters and cyanobacterial blooms on phytoplankton dynamics of a Portuguese temperate lake

    DEFF Research Database (Denmark)

    De Figueiredo, Daniela R.; P. S. Reboleira, Ana Sofia; Antunes, Sara C.

    2006-01-01

    The increasing occurrence of cyanobacterial blooms in freshwaters is of great concern due to the ability of many cyanobacteria to produce cyanotoxins. In the present work, the eutrophied Vela Lake (Central Portugal), used for recreational purposes and as a water source for agriculture, was monito......The increasing occurrence of cyanobacterial blooms in freshwaters is of great concern due to the ability of many cyanobacteria to produce cyanotoxins. In the present work, the eutrophied Vela Lake (Central Portugal), used for recreational purposes and as a water source for agriculture...... (particularly phosphorus). Diatoms were dominant during winter months (inferior temperatures and higher nutrients availability) followed by green algae in early spring and then cyanobacteria from late spring until early autumn (less nutrient availability and higher temperatures). A massive cyanobacterial bloom...... for the phytoplanktonic assemblage during the study period was increased in about 7% achieving a total of 61.0%, indicating a correlation that may be due to the known competitive advantage and/or allelopathy of the bloom-forming cyanobacteria towards microalgae. © Springer 2006....

  6. Proportional-Resonant Controllers. A New Breed of Controllers Suitable for Grid-Connected Voltage-Source Converters

    DEFF Research Database (Denmark)

    Teodorescu, Remus; Blaabjerg, Frede

    2004-01-01

    This paper is describing the recently introduced proportional-resonant (PR) controllers and their suitability for grid-connected converters current control. It is shown that the known shortcomings associated with PI controllers like steady - state error for single-phase converters and the need...... of decoupling for three-phase converters can be alleviated. Additionally, selective harmonic compensation is also possible with PR controllers. Suggested control-diagrams for three-phase grid converters and active filters are also presented. A practical application of PR current control for a photovoltaic (PV...

  7. 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

  8. Connection Strings Property on ADO Connection Object

    Institute of Scientific and Technical Information of China (English)

    Girigi Deogratias; Wu Min; Cao Weihua

    2002-01-01

    The connection string property on ADO connection object contains the information used to establish a connection to the data source. The syntax, the keyword of that information must be in specific format. Depending on the type of data you are connecting to, you need either specify an OLEDB provider or use on ODBC driver. The biggest problem, the industries face is the proliferation of data access interfaces, and the complexity of creating,maintaining and programming against them, and the network problem when communicating over the Intranet or the Internet. This paper first provides an in-depth look of the standard arguments supported by ADO connection string; then gives the easier way for understanding the meaning, the utility and the syntax of the connection strings property on ADO connection object, and finally proposes solution to work around the problems due to the connection strings errors.

  9. 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

  10. Proportional integral plus multi-frequency resonant current controller for grid-connected voltage source converter under imbalanced and distorted supply voltage conditions

    Institute of Scientific and Technical Information of China (English)

    Jia-bing HU; Wei ZHANG; Hong-sheng WANG; Yi-kang HE; Lie XU

    2009-01-01

    This paper proposes a current control scheme for a grid-connected pulse width modulator (PWM) voltage source converter (GC-VSC) under imbalanced and distorted supply voltage conditions. The control scheme is implemented in the positive synchronously rotating reference frame and composed of a single proportional integral (PI) regulator and multi-frequency resonant controllers tuned at the frequencies of 2ω and 6ω, respectively. The experimental results, with the target of eliminating the active power oscillations and current harmonics on a prototype GC-VSC system, validate the feasibility of the proposed current control scheme during supply voltage imbalance and distortion.

  11. Exploration of the link between Emiliania huxleyi bloom dynamics and aerosol fluxes to the lower Atmosphere

    Science.gov (United States)

    Trainic, M.

    2013-12-01

    Phytoplankton blooms are responsible for about 50% of the global photosynthesis, thus are a key component of the major nutrient cycles in the ocean. These blooms can be a significant source for flux of volatiles and aerosols, affecting physical chemical processes in the atmosphere. One of the most widely distributed and abundant phytoplankton species in the oceans is the coccolithophore Emiliania huxleyi. In this research, we explore the influence of the different stages of E. huxleyi bloom on the emission of primary aerosols. For this purpose, we conducted a series of controlled lab experiments to measure aerosol emissions during the growth of E. huxleyi. The cultures were grown in a specially designed growth chamber, and the aerosols were generated in a bubbling system. We collected the emitted aerosol particles on filters, and conducted a series of analysis. Scanning electron microscopy (SEM) analysis of the aerosols emitted from E.huxleyi 1216 cultures demonstrate emission of CaCO3 platelets from their exoskeleton into the air, while coccolithophores cells were absent. The results suggest that while healthy coccolithophore cells are too heavy to aerosolize, during cell lysis the coccoliths shed from the coccolithophore cells are emitted into the atmosphere. Therefore, aerosol production during bloom demise may be greater than from healthy E.huxleyi populations. We also investigated the size distribution of the aerosols at various stages of E. huxleyi growth. The presence of calcified cells greatly effects the size distribution of the emitted aerosol population. This work motivated us to explore aerosols emitted during E. huxleyi spring bloom, in a laboratory we constructed onboard the R/V Knorr research vessel, as part of the North Atlantic Virus Infection of Coccolithophore Expedition (June-July 2012). These results have far-reaching implications on the effect of E. huxleyi bloom dynamics on aerosol properties. We not only show that the E. huxleyi calcite

  12. 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

  13. Is Bloom's Taxonomy Appropriate for Computer Science?

    OpenAIRE

    Johnson, Colin G.; Fuller, Ursula

    2007-01-01

    Bloom's taxonomy attempts to provide a set of levels of cognitive engagement with material being learned. It is usually presented as a generic framework. In this paper we outline some studies which examine whether the taxonomy is appropriate for computing, and how its application in computing might differ from its application elsewhere. We place this in the context of ongoing debates concerning graduateness and attempts to benchmark the content of a computing degree.

  14. Warming accelerates termination of a phytoplankton spring bloom by fungal parasites.

    Science.gov (United States)

    Frenken, Thijs; Velthuis, Mandy; de Senerpont Domis, Lisette N; Stephan, Susanne; Aben, Ralf; Kosten, Sarian; van Donk, Ellen; Van de Waal, Dedmer B

    2016-01-01

    Climate change is expected to favour infectious diseases across ecosystems worldwide. In freshwater and marine environments, parasites play a crucial role in controlling plankton population dynamics. Infection of phytoplankton populations will cause a transfer of carbon and nutrients into parasites, which may change the type of food available for higher trophic levels. Some phytoplankton species are inedible to zooplankton, and the termination of their population by parasites may liberate otherwise unavailable carbon and nutrients. Phytoplankton spring blooms often consist of large diatoms inedible for zooplankton, but the zoospores of their fungal parasites may serve as a food source for this higher trophic level. Here, we investigated the impact of warming on the fungal infection of a natural phytoplankton spring bloom and followed the response of a zooplankton community. Experiments were performed in ca. 1000 L indoor mesocosms exposed to a controlled seasonal temperature cycle and a warm (+4 °C) treatment in the period from March to June 2014. The spring bloom was dominated by the diatom Synedra. At the peak of infection over 40% of the Synedra population was infected by a fungal parasite (i.e. a chytrid) in both treatments. Warming did not affect the onset of the Synedra bloom, but accelerated its termination. Peak population density of Synedra tended to be lower in the warm treatments. Furthermore, Synedra carbon: phosphorus stoichiometry increased during the bloom, particularly in the control treatments. This indicates enhanced phosphorus limitation in the control treatments, which may have constrained chytrid development. Timing of the rotifer Keratella advanced in the warm treatments and closely followed chytrid infections. The chytrids' zoospores may thus have served as an alternative food source to Keratella. Our study thus emphasizes the importance of incorporating not only nutrient limitation and grazing, but also parasitism in understanding the

  15. Phytoplankton blooms weakly influence the cloud forming ability of sea spray aerosol

    Science.gov (United States)

    Collins, Douglas B.; Bertram, Timothy H.; Sultana, Camille M.; Lee, Christopher; Axson, Jessica L.; Prather, Kimberly A.

    2016-09-01

    After many field studies, the establishment of connections between marine microbiological processes, sea spray aerosol (SSA) composition, and cloud condensation nuclei (CCN) has remained an elusive challenge. In this study, we induced algae blooms to probe how complex changes in seawater composition impact the ability of nascent SSA to act as CCN, quantified by using the apparent hygroscopicity parameter (κapp). Throughout all blooms, κapp ranged between 0.7 and 1.4 (average 0.95 ± 0.15), consistent with laboratory investigations using algae-produced organic matter, but differing from climate model parameterizations and in situ SSA generation studies. The size distribution of nascent SSA dictates that changes in κapp associated with biological processing induce less than 3% change in expected CCN concentrations for typical marine cloud supersaturations. The insignificant effect of hygroscopicity on CCN concentrations suggests that the SSA production flux and/or secondary aerosol chemistry may be more important factors linking ocean biogeochemistry and marine clouds.

  16. Remote Sensing as a Tool to Track Algal Blooms in the Great Salt Lake, Utah, USA

    Science.gov (United States)

    Bradt, S. R.; Wurtsbaugh, W. A.; Naftz, D.; Moore, T.; Haney, J.

    2006-12-01

    The Great Salt Lake is a large hypersaline, terminal water body in northern Utah, USA. The lake has both a significant economic importance to the local community as a source of brine shrimp and mineral resources, as well as, an ecological importance to large numbers of migratory waterfowl. Due to nutrient input from sewage treatment plants, sections of the Great Salt Lake are subjected to highly eutrophic conditions. One of the main tributaries, Farmington Bay, experiences massive blooms of cyanobacteria which can reach concentrations in excess of 300 mg l-1 in the bay. Effects of these blooms can be observed stretching into the rest of the lake. The detrimental outcomes of the blooms include unsightly scums, foul odor and the danger of cyanobacterial toxins. While the blooms have an obvious effect on Farmington Bay, it is quite possible that the cyanobacteria impact a much wider area of the lake as currents move eutrophic water masses. Of particular interest is the reaction of brine shrimp to the plumes of cyanobacteria-rich water leaving Farmington Bay. We are employing remote sensing as a tool to map the distribution of algae throughout the lake and produce lake-wide maps of water quality on a regular basis. On-lake reflectance measurements have been coupled with MODIS satellite imagery to produce a time series of maps illustrating changes in algal distribution. The successes and shortcomings of our remote sensing technique will be a central topic of this presentation.

  17. Method of anti-blooming in measurement of low-light-level television

    Science.gov (United States)

    Zhu, Jiali; Liu, Xiaodong; Zhang, Ping; Hao, Fang; Zhang, Shiming

    2013-08-01

    Blooming is a normal phenomenon in the measurement of low light level television (LLL TV) due to its inner auto-gain control, which will influence the test result and should be controlled in the measurement process. Analyzing the blooming principle, a solving method was improved by increasing the ambient illumination on the sense of LLL TV, which will decrease the auto-gain value of LLL TV. What's more, this method was validated in an experiment of resolution measurement of LLL TV by the applying an auxiliary lighting equipment. The auxiliary light equipment was composed with three ground glasses, twelve LED lamps, and a box brushed with diffuse materials inside. The color temperature of LED lamps was 3000K whose value is close to the light source (2856K) of resolution measurement. During the experiment, auxiliary light equipment was placed in front of the LLL TV. By analyzing the output image of the LLL TV, the blooming phenomenon disappeared and the covered resolution image appeared. The result means that the method of increasing the ambient illumination on the sense of LLL TV is an effective way to depress the blooming in measurement of LLL TV, and it can be used to other parameter measurement of LLL TV.

  18. Connecting multiple clouds and mixing real and virtual resources via the open source WNoDeS framework

    CERN Document Server

    CERN. Geneva; Italiano, Alessandro

    2012-01-01

    In this paper we present the latest developments introduced in the WNoDeS framework (http://web.infn.it/wnodes); we will in particular describe inter-cloud connectivity, support for multiple batch systems, and coexistence of virtual and real environments on a single hardware. Specific effort has been dedicated to the work needed to deploy a "multi-sites" WNoDeS installation. The goal is to give end users the possibility to submit requests for resources using cloud interfaces on several sites in a transparent way. To this extent, we will show how we have exploited already existing and deployed middleware within the framework of the IGI (Italian Grid Initiative) and EGI (European Grid Infrastructure) services. In this context, we will also describe the developments that have taken place in order to have the possibility to dynamically exploit public cloud services like Amazon EC2. The latter gives WNoDeS the capability to serve, for example, part of the user requests through external computing resources when ne...

  19. A new connection between the opening angle and the large-scale morphology of extragalactic radio sources

    CERN Document Server

    Krause, Martin; Riley, Julia; Hopton, Daniel

    2012-01-01

    In the case of an initially conical jet, we study the relation between jet collimation by the external pressure and large-scale morphology. We first consider the important length-scales in the problem, and then carry out axisymmetric hydrodynamic simulations that include, for certain parameters, all these length-scales. We find three important scales related to the collimation region: (i) where the sideways ram-pressure equals the external pressure, (ii) where the jet density equals the ambient density, and (iii) where the forward ram-pressure falls below the ambient pressure. These scales are set by the external Mach-number and opening angle of the jet. We demonstrate that the relative magnitudes of these scales determine the collimation, Mach-number, density and morphology of the large scale jet. Based on analysis of the shock structure, we reproduce successfully the morphology of Fanaroff-Riley (FR) class I and II radio sources. Within the framework of the model, an FR I radio source must have a large intr...

  20. 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

  1. 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.

  2. Does the Sverdrup critical depth model explain bloom dynamics in estuaries?

    Science.gov (United States)

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

    1998-01-01

    In this paper we use numerical models of coupled biological-hydrodynamic processes to search for general principles of bloom regulation in estuarine waters. We address three questions: what are the dynamics of stratification in coastal systems as influenced by variable freshwater input and tidal stirring? How does phytoplankton growth respond to these dynamics? Can the classical Sverdrup Critical Depth Model (SCDM) be used to predict the timing of bloom events in shallow coastal domains such as estuaries? We present results of simulation experiments which assume that vertical transport and net phytoplankton growth rates are horizontally homogeneous. In the present approach the temporally and spatially varying turbulent diffusivities for various stratification scenarios are calculated using a hydrodynamic code that includes the Mellor-Yamada 2.5 turbulence closure model. These diffusivities are then used in a time- and depth-dependent advection-diffusion equation, incorporating sources and sinks, for the phytoplankton biomass. Our modeling results show that, whereas persistent stratification greatly increases the probability of a bloom, semidiurnal periodic stratification does not increase the likelihood of a phytoplankton bloom over that of a constantly unstratified water column. Thus, for phytoplankton blooms, the physical regime of periodic stratification is closer to complete mixing than to persistent stratification. Furthermore, the details of persistent stratification are important: surface layer depth, thickness of the pycnocline, vertical density difference, and tidal current speed all weigh heavily in producing conditions which promote the onset of phytoplankton blooms. Our model results for shallow tidal systems do not conform to the classical concepts of stratification and blooms in deep pelagic systems. First, earlier studies (Riley, 1942, for example) suggest a monotonic increase in surface layer production as the surface layer shallows. Our model

  3. Approaches to monitoring, control and management of harmful algal blooms (HABs).

    Science.gov (United States)

    Anderson, Donald M

    2009-07-01

    Virtually every coastal country in the world is affected by harmful algal blooms (HABs, commonly called "red tides"). These phenomena are caused by blooms of microscopic algae. Some of these algae are toxic, and can lead to illness and death in humans, fish, seabirds, marine mammals, and other oceanic life, typically as a result of the transfer of toxins through the food web. Sometimes the direct release of toxic compounds can be lethal to marine animals. Non-toxic HABs cause damage to ecosystems, fisheries resources, and recreational facilities, often due to the sheer biomass of the accumulated algae. The term "HAB" also applies to non-toxic blooms of macroalgae (seaweeds), which can cause major ecological impacts such as the displacement of indigenous species, habitat alteration and oxygen depletion in bottom waters.Globally, the nature of the HAB problem has changed considerably over the last several decades. The number of toxic blooms, the resulting economic losses, the types of resources affected, and the number of toxins and toxic species have all increased dramatically. Some of this expansion has been attributed to storms, currents and other natural phenomena, but human activities are also frequently implicated. Humans have contributed by transporting toxic species in ballast water, and by adding massive and increasing quantities of industrial, agricultural and sewage effluents to coastal waters. In many urbanized coastal regions, these inputs have altered the size and composition of the nutrient pool which has, in turn, created a more favorable nutrient environment for certain HAB species. The steady expansion in the use of fertilizers for agricultural production represents a large and worrisome source of nutrients in coastal waters that promote some HABs.The diversity in HAB species and their impacts presents a significant challenge to those responsible for the management of coastal resources. Furthermore, HABs are complex oceanographic phenomena that

  4. Biology in bloom: implementing Bloom's Taxonomy to enhance student learning in biology.

    Science.gov (United States)

    Crowe, Alison; Dirks, Clarissa; Wenderoth, Mary Pat

    2008-01-01

    We developed the Blooming Biology Tool (BBT), an assessment tool based on Bloom's Taxonomy, to assist science faculty in better aligning their assessments with their teaching activities and to help students enhance their study skills and metacognition. The work presented here shows how assessment tools, such as the BBT, can be used to guide and enhance teaching and student learning in a discipline-specific manner in postsecondary education. The BBT was first designed and extensively tested for a study in which we ranked almost 600 science questions from college life science exams and standardized tests. The BBT was then implemented in three different collegiate settings. Implementation of the BBT helped us to adjust our teaching to better enhance our students' current mastery of the material, design questions at higher cognitive skills levels, and assist students in studying for college-level exams and in writing study questions at higher levels of Bloom's Taxonomy. From this work we also created a suite of complementary tools that can assist biology faculty in creating classroom materials and exams at the appropriate level of Bloom's Taxonomy and students to successfully develop and answer questions that require higher-order cognitive skills.

  5. An active learning approach to Bloom's Taxonomy.

    Science.gov (United States)

    Weigel, Fred K; Bonica, Mark

    2014-01-01

    As educators strive toward improving student learning outcomes, many find it difficult to instill their students with a deep understanding of the material the instructors share. One challenge lies in how to provide the material with a meaningful and engaging method that maximizes student understanding and synthesis. By following a simple strategy involving Active Learning across the 3 primary domains of Bloom's Taxonomy (cognitive, affective, and psychomotor), instructors can dramatically improve the quality of the lesson and help students retain and understand the information. By applying our strategy, instructors can engage their students at a deeper level and may even find themselves enjoying the process more.

  6. Subsurface phytoplankton blooms fuel pelagic production in the North Sea

    DEFF Research Database (Denmark)

    Richardson, Kathrine; Visser, Andre; Pedersen, Flemming

    2000-01-01

    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...

  7. WATER BLOOM OF BLUEGREEN ALGE IN CARP FISHPOUNDS

    Directory of Open Access Journals (Sweden)

    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.

  8. The Self According to Allan Bloom and Charles Reich.

    Science.gov (United States)

    Aspy, David N.; Aspy, Cheryl B.

    1998-01-01

    Discusses the works of Charles Reich and Allan Bloom that have helped to shape current social and political debate concerning self theory. Both Reich and Bloom were concerned with the relationship between self and environment. Argues that it is important to insure that its cultural role of self theory is clearly interpreted and applied. (MKA)

  9. The Evolution of Educational Objectives: Bloom's Taxonomy and beyond

    Science.gov (United States)

    Fallahi, Carolyn R.; LaMonaca, Frank H., Jr.

    2009-01-01

    It is crucial for teachers to communicate effectively about educational objectives to students, colleagues, and others in education. In 1956, Bloom developed a cognitive learning taxonomy to enhance communication between college examiners. The Bloom taxonomy consists of 6 hierarchical levels of learning (knowledge, comprehension, application,…

  10. 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…

  11. sources

    Directory of Open Access Journals (Sweden)

    Shu-Yin Chiang

    2002-01-01

    Full Text Available In this paper, we study the simplified models of the ATM (Asynchronous Transfer Mode multiplexer network with Bernoulli random traffic sources. Based on the model, the performance measures are analyzed by the different output service schemes.

  12. Subsurface seeding of surface harmful algal blooms observed through the integration of autonomous gliders, moored environmental sample processors, and satellite remote sensing in southern California

    KAUST Repository

    Seegers, Bridget N.

    2015-04-01

    An observational study was performed in the central Southern California Bight in Spring 2010 to understand the relationship between seasonal spring phytoplankton blooms and coastal processes that included nutrient input from upwelling, wastewater effluent plumes, and other processes. Multi-month Webb Slocum glider deployments combined with MBARI environmental sample processors (ESPs), weekly pier sampling, and ocean color data provided a multidimensional characterization of the development and evolution of harmful algal blooms (HABs). Results from the glider and ESP observations demonstrated that blooms of toxic Pseudo-nitzschia sp. can develop offshore and subsurface prior to their manifestation in the surface layer and/or near the coast. A significant outbreak and surface manifestation of the blooms coincided with periods of upwelling, or other processes that caused shallowing of the pycnocline and subsurface chlorophyll maximum. Our results indicate that subsurface populations can be an important source for “seeding” surface Pseudo-nitzschia HAB events in southern California.

  13. 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.

  14. Phytoplankton Bloom in North Sea off Scotland

    Science.gov (United States)

    2008-01-01

    The northern and western highlands of Scotland were still winter-brown and even dusted with snow in places, but the waters of the North Sea were blooming with phytoplankton on May 8, 2008, when the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Aqua satellite passed over the region and captured this image. The tiny, plant-like organisms swirled in the waters off the country's east coast, coloring the shallow coastal waters shades of bright blue and green. Phytoplankton are tiny organisms--many are just a single cell--that use chlorophyll and other pigments to capture light for photosynthesis. Because these pigments absorb sunlight, they change the color of the light reflected from the sea surface back to the satellite. Scientists have used observations of 'ocean color' from satellites for more than 20 years to track worldwide patterns in phytoplankton blooms. Phytoplankton are important to the Earth system for a host of reasons, including their status as the base of the ocean food web. In the North Sea, they are the base of the food web that supports Scotland's commercial fisheries, including monkfish and herring. As photosynthesizers, they also play a crucial role in the carbon cycle, removing carbon dioxide from the atmosphere. Some oceanographers are concerned that rising ocean temperatures will slow phytoplankton growth rates, harming marine ecosystems and causing carbon dioxide to accumulate more rapidly in the atmosphere.

  15. RECOMMENDATION SYSTEM USING BLOOM FILTER IN MAPREDUCE

    Directory of Open Access Journals (Sweden)

    Reena Pagare

    2013-11-01

    Full Text Available Many clients like to use the Web to discover product details in the form of online reviews. The reviews are provided by other clients and specialists. Recommender systems provide an important response to the information overload problem as it presents users more practical and personalized information facilities. Collaborative filtering methods are vital component in recommender systems as they generate high-quality recommendations by influencing the likings of society of similar users. The collaborative filtering method has assumption that people having same tastes choose the same items. The conventional collaborative filtering system has drawbacks as sparse data problem & lack of scalability. A new recommender system is required to deal with the sparse data problem & produce high quality recommendations in large scale mobile environment. MapReduce is a programming model which is widely used for large-scale data analysis. The described algorithm of recommendation mechanism for mobile commerce is user based collaborative filtering using MapReduce which reduces scalability problem in conventional CF system. One of the essential operations for the data analysis is join operation. But MapReduce is not very competent to execute the join operation as it always uses all records in the datasets where only small fraction of datasets are applicable for the join operation. This problem can be reduced by applying bloomjoin algorithm. The bloom filters are constructed and used to filter out redundant intermediate records. The proposed algorithm using bloom filter will reduce the number of intermediate results and will improve the join performance.

  16. Source to sink: Evolution of lignin composition in the Madre de Dios River system with connection to the Amazon basin and offshore

    Science.gov (United States)

    Feng, Xiaojuan; Feakins, Sarah J.; Liu, Zongguang; Ponton, Camilo; Wang, Renée. Z.; Karkabi, Elias; Galy, Valier; Berelson, William M.; Nottingham, Andrew T.; Meir, Patrick; West, A. Joshua

    2016-05-01

    While lignin geochemistry has been extensively investigated in the Amazon River, little is known about lignin distribution and dynamics within deep, stratified river channels or its transformations within soils prior to delivery to rivers. We characterized lignin phenols in soils, river particulate organic matter (POM), and dissolved organic matter (DOM) across a 4 km elevation gradient in the Madre de Dios River system, Peru, as well as in marine sediments to investigate the source-to-sink evolution of lignin. In soils, we found more oxidized lignin in organic horizons relative to mineral horizons. The oxidized lignin signature was maintained during transfer into rivers, and lignin was a relatively constant fraction of bulk organic carbon in soils and riverine POM. Lignin in DOM became increasingly oxidized downstream, indicating active transformation of dissolved lignin during transport, especially in the dry season. In contrast, POM accumulated undegraded lignin downstream during the wet season, suggesting that terrestrial input exceeded in-river degradation. We discovered high concentrations of relatively undegraded lignin in POM at depth in the lower Madre de Dios River in both seasons, revealing a woody undercurrent for its transfer within these deep rivers. Our study of lignin evolution in the soil-river-ocean continuum highlights important seasonal and depth variations of river carbon components and their connection to soil carbon pools, providing new insights into fluvial carbon dynamics associated with the transfer of lignin biomarkers from source to sink.

  17. A New Control Method for Grid-Connected PV System Based on Quasi-Z-Source Cascaded Multilevel Inverter Using Evolutionary Algorithm

    Directory of Open Access Journals (Sweden)

    Hamid Reza Mohammadi

    2015-03-01

    Full Text Available In this paper, a new control method for quasi-Z-source cascaded multilevel inverter based grid-connected photovoltaic (PV system is proposed. The proposed method is capable of boosting the PV array voltage to a higher level and solves the imbalance problem of DC-link voltage in traditional cascaded H-bridge inverters. The proposed control system adjusts the grid injected current in phase with the grid voltage and achieves independent maximum power point tracking (MPPT for the separate PV arrays. To achieve these goals, the proportional-integral (PI controllers are employed for each module. For achieving the best performance, this paper presents an optimum approach to design the controller parameters using particle swarm optimization (PSO. The primary design goal is to obtain good response by minimizing the integral absolute error. Also, the transient response is guaranteed by minimizing the overshoot, settling time and rise time of the system response. The effectiveness of the new proposed control method has been verified through simulation studies based on a seven level quasi-Z-Source cascaded multilevel inverter.

  18. An investigation of submarine groundwater-borne nutrient fluxes to the west Florida shelf and recurrent harmful algal blooms

    Science.gov (United States)

    Smith, Christopher G.; Swarzenski, Peter W.

    2012-01-01

    A cross-shelf, water-column mass balance of radon-222 (222Rn) provided estimates of submarine groundwater discharge (SGD), which were then used to quantify benthic nutrient fluxes. Surface water and groundwater were collected along a shore-normal transect that extended from Tampa Bay, Florida, across the Pinellas County peninsula, to the 10-m isobath in the Gulf of Mexico. Samples were analyzed for 222Rn and radium-223,224,226 (223,224,226Ra) activities as well as inorganic and organic nutrients. Cross-shore gradients of 222Rn and 223,224,226Ra activities indicate a nearshore source for these isotopes, which mixes with water characterized by low activities offshore. Radon-based SGD rates vary between 2.5 and 15 cm d-1 proximal to the shoreline and decrease offshore. The source of SGD is largely shallow exchange between surface and pore waters, although deeper groundwater cycling may also be important. Enrichment of total dissolved nitrogen and soluble reactive phosphorus in pore water combined with SGD rates results in specific nutrient fluxes comparable to or greater than estuarine fluxes from Tampa Bay. The significance of these fluxes to nearshore blooms of Karenia brevis is highlighted by comparison with prescribed nutrient demands for bloom maintenance and growth. Whereas our flux estimates do not indicate SGD and benthic fluxes as the dominant nutrient source to the harmful algal blooms, SGD-derived loads do narrow the deficit between documented nutrient supplies and bloom demands.

  19. Incestuous rape, abjection, and the colonization of psychic space in Toni Morrison’s The Bluest Eye and Shani Mootoo’s Cereus Blooms at Night

    NARCIS (Netherlands)

    E.M. Koopman (Emy)

    2013-01-01

    textabstractToni Morrison’s The Bluest Eye (1970) and Shani Mootoo’s Cereus Blooms at Night (1996) both apply a strategy of connecting rape to other forms of oppression, suggesting that incest is at least partly the result of the dynamics of being colonized and “othered”. This article brings out the

  20. Satellite views of the massive algal bloom in the Persian Gulf and the Gulf of Oman during 2008-2009

    Science.gov (United States)

    Yu, Shujie; Gong, Fang; He, Xianqiang; Bai, Yan; Zhu, Qiankun; Wang, Difeng; Chen, Peng

    2016-10-01

    The Persian Gulf and the Gulf of Oman locate at the northwest of the Arabian Sea, with the total area more than 50,0000 km2. The Persian Gulf is a semi-enclosed subtropical sea with high water temperature, extremely high salinity, and an average depth of 50 meters. By the Strait of Hormuz, the Persian Gulf is connected to the Gulf of Oman which is significantly affected by the monsoonal winds and by water exchange between the Arabian Sea and the Persian Gulf. Algal blooms occurred frequently in the Persian Gulf and the Gulf of Oman, and some of them are harmful algal blooms which may lead to massive fish death and thereby serious economic loss. Due to the widely spatial coverage and temporal variation, it is difficult to monitoring the dynamic of the algal bloom based on in situ measurement. In this study, we used the remote sensing data from the Moderate Resolution Imaging Spectroradiometer (MODIS) onboard the Aqua satellite to investigate a massive algal bloom event in the Persian Gulf and the Gulf of Oman during 2008-2009. The time series of MODIS-derived chlorophyll concentration (Chl-a) indicated that the bloom event with high Chl-a concentration ( 60 percent higher than corresponding climatological data) appeared to lasting more than 8 months from autumn of 2008 to spring of 2009. In addition, the bloom was widespread from the Persian Gulf to the Gulf of Oman and neighboring open ocean. The MODIS-derived net primary production (NPP) collected from MODIS showed the same trend with Chl-a. Multiple forces including upwelling, dust deposition was taken into account to elucidate the mechanisms for the long-lasting algal bloom. The time series chlorophyll concentration of the Persian Gulf emerges a significant seasonal pattern with maximum concentrations seen during the winter time and lowest during the summer. It also indicated slight disturbances occurred in June (May/July) and December (November/ January) in some years. The sea surface temperature and water

  1. Connected Traveler

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, Alex

    2015-11-01

    The Connected Traveler project is a multi-disciplinary undertaking that seeks to validate potential for transformative transportation system energy savings by incentivizing efficient traveler behavior. This poster outlines various aspects of the Connected Traveler project, including market opportunity, understanding traveler behavior and decision-making, automation and connectivity, and a projected timeline for Connected Traveler's key milestones.

  2. Harmful Algal Blooms and Public Health

    Science.gov (United States)

    Grattan, Lynn M.; Holobaugh, Sailor; Morris, J. Glenn

    2015-01-01

    The five most commonly recognized Harmful Algal Bloom related illnesses include Ciguatera poisoning, Paralytic Shellfish poisoning, Neurotoxin Shellfish poisoning, Diarrheic Shellfish Poisoning and Amnesic Shellfish poisoning. Although they are each the product of different toxins, toxin assemblages or HAB precursors these clinical syndromes have much in common. Exposure occurs through the consumption of fish or shellfish; routine clinical tests are not available for diagnosis; there is no known antidote for exposure; and the risk of these illnesses can negatively impact local fishing and tourism industries. Thus, illness prevention is of paramount importance to minimize human and public health risks. To accomplish this, close communication and collaboration is needed among HAB scientists, public health researchers and local, state and tribal health departments at academic, community outreach, and policy levels. PMID:27616971

  3. Harmful Algal Bloom Research in China

    Institute of Scientific and Technical Information of China (English)

    Su Jilan; Zhou Mingjiang

    2001-01-01

    Proliferations of harmful algae in coastal waters, i.e., harmful algal blooms (HABs), popularly known as "red tides," have attracted the concern of governments and scientists worldwide. In recent years, HABs have occurred in China with increasing frequency and scope. These outbreaks have seriously affected the economy along the coast through fish kills, heavy losses in aquaculture, threats to human health, and other effects detrimental to the marine ecosystem. Therefore, it is important to pay special attention to the ecology and oceanography studies related to the outbreak of HABs. Only through the combination of the advancement of such knowledge with the strengthening of the monitoring network can we develop a HAB warning system for the sustainable development of the coastal economy.

  4. Harmful Algal Blooms and Public Health.

    Science.gov (United States)

    Grattan, Lynn M; Holobaugh, Sailor; Morris, J Glenn

    2016-07-01

    The five most commonly recognized Harmful Algal Bloom related illnesses include Ciguatera poisoning, Paralytic Shellfish poisoning, Neurotoxin Shellfish poisoning, Diarrheic Shellfish Poisoning and Amnesic Shellfish poisoning. Although they are each the product of different toxins, toxin assemblages or HAB precursors these clinical syndromes have much in common. Exposure occurs through the consumption of fish or shellfish; routine clinical tests are not available for diagnosis; there is no known antidote for exposure; and the risk of these illnesses can negatively impact local fishing and tourism industries. Thus, illness prevention is of paramount importance to minimize human and public health risks. To accomplish this, close communication and collaboration is needed among HAB scientists, public health researchers and local, state and tribal health departments at academic, community outreach, and policy levels.

  5. Physical Hydrography and Algal Bloom Transport in Hong Kong Waters

    Institute of Scientific and Technical Information of China (English)

    KUANG Cui-ping; LEE Joseph H.W.

    2005-01-01

    In sub-tropical coastal waters around Hong Kong, algal blooms and red tides are usually first sighted in the Mirs Bay, in the eastern waters of Hong Kong. A calibrated three-dimensional hydrodynamic model for the Pearl River Estuary (Delft3D) has been applied to the study of the physical hydrography of Hong Kong waters and its relationship with algal bloom transport patterns in the dry and wet seasons. The general 3D hydrodynamic circulation and salinity structure in the partially-mixed estuary are presented. Extensive numerical surface drogue tracking experiments are performed for algal blooms that are initiated in the Mirs Bay under different seasonal, wind and tidal conditions. The probability of bloom impact on the Victoria Harbour and nearby urban coastal waters is estimated. The computations show that: I) In the wet season (May~August), algal blooms initiated in the Mirs Bay will move in a clockwise direction out of the bay, and be transported away from Hong Kong due to SW monsoon winds which drive the SW to NE coastal current; ii) In the dry season (November~April), algal blooms initiated in the northeast Mirs Bay will move in an anti-clockwise direction and be carried away into southern waters due to the NE to SW coastal current driven by the NE monsoon winds; the bloom typically flows past the east edge of the Victoria Harbour and nearby waters. Finally, the role of hydrodynamic transport in an important episodic event - the spring 1998 massive red tide - is quantitatively examined. It is shown that the strong NE to E wind during late March to early April, coupled with the diurnal tide at the beginning of April, significantly increased the probability of bloom transport into the Port Shelter and East Lamma Channel, resulting in the massive fish kill. The results provide a basis for risk assessment of harmful algal bloom (HAB) impact on urban coastal waters around the Victoria Habour.

  6. Seasonal phytoplankton blooms in the North Atlantic linked to the overwintering strategies of copepods

    Directory of Open Access Journals (Sweden)

    Kevin D. Friedland

    2016-04-01

    Full Text Available Abstract The North Atlantic Ocean contains diverse patterns of seasonal phytoplankton blooms with distinct internal dynamics. We analyzed blooms using remotely-sensed chlorophyll a concentration data and change point statistics. The first bloom of the year began during spring at low latitudes and later in summer at higher latitudes. In regions where spring blooms occurred at high frequency (i.e., proportion of years that a bloom was detected, there was a negative correlation between bloom timing and duration, indicating that early blooms last longer. In much of the Northeast Atlantic, bloom development extended over multiple seasons resulting in peak chlorophyll concentrations in summer. Spring bloom start day was found to be positively correlated with a spring phenology index and showed both positive and negative correlations to sea surface temperature and the North Atlantic Oscillation in different regions. Based on the characteristics of spring and summer blooms, the North Atlantic can be classified into two regions: a seasonal bloom region, with a well-defined bloom limited to a single season; and a multi-seasonal bloom region, with blooms extending over multiple seasons. These regions differed in the correlation between bloom start and duration with only the seasonal bloom region showing a significant, negative correlation. We tested the hypothesis that the near-surface springtime distribution of copepods that undergo diapause (Calanus finmarchicus, C. helgolandicus, C. glacialis, and C. hyperboreus may contribute to the contrast in bloom development between the two regions. Peak near-surface spring abundance of the late stages of these Calanoid copepods was generally associated with areas having a well-defined seasonal bloom, implying a link between bloom shape and their abundance. We suggest that either grazing is a factor in shaping the seasonal bloom or bloom shape determines whether a habitat is conducive to diapause, while recognizing

  7. Optical researches for cyanobacteria bloom monitoring in Curonian Lagoon

    Science.gov (United States)

    Shirshin, Evgeny A.; Budylin, Gleb B.; Yakimov, Boris P.; Voloshina, Olga V.; Karabashev, Genrik S.; Evdoshenko, Marina A.; Fadeev, Victor V.

    2016-04-01

    Cyanobacteria bloom is a great ecological problem of Curonian Lagoon and Baltic Sea. The development of novel methods for the on-line control of cyanobacteria concentration and, moreover, for prediction of bloom spreading is of interest for monitoring the state of ecosystem. Here, we report the results of the joint application of hyperspectral measurements and remote sensing of Curonian Lagoon in July 2015 aimed at the assessment of cyanobacteria communities. We show that hyperspectral data allow on-line detection and qualitative estimation of cyanobacteria concentration, while the remote sensing data indicate the possibility of cyanobacteria bloom detection using the spectral features of upwelling irradiation.

  8. Marine harmful algal blooms, human health and wellbeing

    DEFF Research Database (Denmark)

    Berdalet, Elisa; Fleming, Lora E.; Gowen, Richard

    2016-01-01

    Microalgal blooms are a natural part of the seasonal cycle of photosynthetic organisms in marine ecosystems. They are key components of the structure and dynamics of the oceans and thus sustain the benefits that humans obtain from these aquatic environments. However, some microalgal blooms can...... cause harm to humans and other organisms. These harmful algal blooms (HABs) have direct impacts on human health and negative influences on human wellbeing, mainly through their consequences to coastal ecosystem services (fisheries, tourism and recreation) and other marine organisms and environments...

  9. The state of U.S. freshwater harmful algal blooms assessments, policy and legislation.

    Science.gov (United States)

    Hudnell, H Kenneth

    2010-05-01

    The incidence of harmful algal blooms (HABs) is increasing in the United States and worldwide. HAB toxins cause a substantial but unquantified amount of human and animal morbidity and mortality from exposures in recreational, commercial, drinking-source and potable waters. HAB biomass and toxins threaten the sustainability of aquatic ecosystems. U.S. Congressional legislation mandated the establishment of a National Research Plan for Coastal Harmful Algal Blooms, but no similar plan exists for freshwater HABs (FHABs). Eutrophication and FHABs are conservatively estimated to cost the U.S. economy 2.2-4.6 billion dollars annually. A National Research Plan for Freshwater Harmful Algal Blooms is needed to develop U.S. policy and regulations or guidelines to confront FHAB risks. This report reviews the state of FHAB occurrence, risk and risk management assessments in the U.S. Research is identified that must be accomplished to characterize occurrence and risks, and develop cost effective strategies for preventing, suppressing and mitigating FHABs. U.S. Congressional legislation is needed to mandate a National Research Plan for FHABs, establish a timeline for developing policy and fund competitive research-grant programs. The research results will provide a sound scientific basis for making policy determinations and implementing risk management strategies. Successfully confronting FHAB risks will strengthen the U.S. economy, protect human and animal health and help ensure the sustainability of our Nation's freshwater bodies.

  10. Unusual phytoplankton bloom phenology in the northern Greenland Sea during 2010

    Science.gov (United States)

    Qu, Bo; Gabric, Albert J.; Lu, Zhifeng; Li, Hehe; Zhao, Li

    2016-12-01

    Arctic marine ecosystems are disproportionately impacted by global warming. Sea ice plays an important role in the regional climate system and the loss of perennial sea ice has diverse ecological implications. Here we investigate the causes of an unusually early and strong phytoplankton bloom in the northern Greenland Sea (20°W-10°E, 75°N-80°N) during the 2010 season. In order to better understand the anomalous bloom in 2010, we examine the correlation between satellite-derived biomass and several possible environmental factors for the period 2003-2012. Results show that the timing of sea ice melt played an important role in promoting the growth of phytoplankton. Multivariate lagged regression analysis shows that phytoplankton biomass (CHL) is correlated with ice concentration (ICE) and ice melting, as well as sea surface temperature (SST) and photosynthetically active radiation (PAR). During 2010, the spring peak in biomass came much earlier and achieved a higher value than most other years in the satellite archive record, which was due to earlier and more extensive sea ice melt in that year. Relative lower SST and PAR in spring and early summer in year 2010 associated with a persistent negative North Atlantic Oscillation (NAO) index were possible drivers of the bloom. Wind direction changed from the southeast to southwest direction in spring, possibly transporting nutrient enriched melt runoff from glaciers on Greenland and other sources from the south to northern coastal regions.

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

    Science.gov (United States)

    Soto Ramos, Inia Mariel

    MODIS data and the new technique developed in Chapter One showed potential for a detection technique that can distinguish between Karenia and Scrippsiella blooms. Additional work is needed to improve the new technique developed for Mexican waters, but results show potential for detection techniques that can be used Gulf-wide. This will help better understand the dynamic and possible connectivity of phytoplankton blooms in the GOM.

  12. Functional deficiency of fibroblasts heterozygous for Bloom syndrome as specific manifestation of the primary defect.

    OpenAIRE

    Bartram, C.R.; Rüdiger, H W; Schmidt-Preuss, U; Passarge, E

    1981-01-01

    The effect on the rate of sister chromatid exchanges (SCEs) in Bloom syndrome fibroblasts by cocultivation with Fanconi anemia and xeroderma pigmentosum fibroblasts and with Bloom syndrome heterozygotes was studied. Cells of Fanconi anemia and xeroderma origin reduced the rate of SCEs in Bloom cells by about 45%-50%, just as control cells do. In contrast, heterozygous Bloom cells reduced the rate of SCEs by only 16%-28%. In absolute figures, Fanconi cells reduced the mean rate of SCE in Bloom...

  13. Nonstructural carbohydrates and return bloom potential differ among cranberry cultivars

    Science.gov (United States)

    explain low fruit set and biennial bearing tendencies of cranberry (Vaccinium macrocarpon). Yet, comparisons of nonstructural carbohydrate concentrations during critical phenological stages across cultivars that differ in biennial bearing tendencies and return bloom potential are lacking, particular...

  14. 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.

  15. 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.

    2004 resulted in nauseating smell emanating from the coastal waters (The Hindu 2004; The Hindustan Times 2004). This bloom resulted in large–scale fish mortality and hospitalization of 200 people especially children who suffered from nausea...

  16. Lyngbya majuscula Blooms in an Enclosed Marine Environment

    Directory of Open Access Journals (Sweden)

    Chin Soon Lionel Ng

    2012-06-01

    Full Text Available Cyanobacterial blooms are a cause of concern because of their potential impacts on the marine environment. In Sentosa Cove, Singapore, Lyngbya majuscula blooms appeared regularly in the highly enclosed boat canals traversing the seafront residential development. This study investigated whether sediments resuspended by physical disturbance liberated nutrients that contribute to the blooms. Sediment resuspension events were mimicked in containers of sediment collected from the canals. Lyngbya majuscula that were incubated in containers with resuspended sediment attained greater biomass than those in filtered seawater only. Levels of iron, phosphates and nitrites in seawater with resuspended sediments were significantly higher than in those without. The results indicate that recurrent L. majuscula blooms in Sentosa Cove could be attributed to nutrient loading from sediment resuspension.

  17. Lagrangian Analysis of Kerguelen's Naturally Iron-fertilised Phytoplankton Bloom

    Science.gov (United States)

    Della Penna, A.; Trull, T. W.; Grenier, M.; Wotherspoon, S.; Johnson, C.; De Monte, S.; d'Ovidio, F.

    2015-12-01

    The role of iron as a limiting micro-nutrient for primary production in High Nutrient Low Chlorophyll regions has been highlighted by paleoceanography, artificial fertilisation experiments and observed naturally fertilised systems. Examples of natural fertilisation have suggested that (sub-)mesoscale (1-100 km, days-months) horizontal transport modulates and structures the spatial and temporal extent of iron enrichment, phytoplankton production and biogeography. Here we combine different satellite products (altimetry, ocean color, PHYSAT), in-situ sampling, drifting floats and autonomous profilers to analyse the naturally iron-fertilised phytoplankton bloom of the Kerguelen region (Southern Ocean). Considering the Kerguelen Plateau as the main local source of iron, we compute two Lagrangian diagnostics: the "age" - how long before a water parcel has touched the plateau- and the "origin" - the latitude where a water parcel has left the plateau. First, we verify that these altimetry-defined diagnostics' spatial patterns -computed using geostrophic and Ekman corrected velocity fields- are coherent with the ones structuring the trajectories of more than 100 drifters and that trends in surface Chlorophyll (Chl) present an overall agreement with total column content (yet with ~2-3x differences in dynamic ranges likely due to the varying presence of Chl below the mixed layer). Second, assuming a first-order removal, we fit "age" with iron measurements and we estimate removal rates for bloom and abiotic conditions of respectively 0.058 and 0.041 1/d. Then, we relate "age" and "origin" with locations of high Chl concentrations and diatom-dominance. We find out that locations of high Chl concentration correspond to water parcels that have recently left the plateau. Furthermore, general additive models reveal that recently enriched waters are more likely to present a diatom dominance. However, the expected exponential fit varies within the geographic domain suggesting that

  18. 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...

  19. Algal Bloom in Aquatic Ecosystems-an Overview

    OpenAIRE

    M. Ghorbani; S.A. Mirbagheri; A. H. Hasani; S. M. Monavari; J.Nouri

    2014-01-01

    Algae play an important role in all aquatic ecosystems by providing all living organisms of water bodies with preliminary nutrients and energy required. However, abnormal and excessive algal growth so-called algal bloom would be detrimental as much. Given the importance of algae in aquatic environment as well as their sensitivity to environmental changes, algal measurements are of key components of water quality monitoring programs. The algal blooms could include a variety of adverse impacts...

  20. Phylogenies of microcystin-producing cyanobacteria in the lower Laurentian Great Lakes suggest extensive genetic connectivity.

    Directory of Open Access Journals (Sweden)

    Timothy W Davis

    Full Text Available Lake St. Clair is the smallest lake in the Laurentian Great Lakes system. MODIS satellite imagery suggests that high algal biomass events have occurred annually along the southern shore during late summer. In this study, we evaluated these events and tested the hypothesis that summer bloom material derived from Lake St. Clair may enter Lake Erie via the Detroit River and represent an overlooked source of potentially toxic Microcystis biomass to the western basin of Lake Erie. We conducted a seasonally and spatially resolved study carried out in the summer of 2013. Our goals were to: 1 track the development of the 2013 summer south-east shore bloom 2 conduct a spatial survey to characterize the extent of toxicity, taxonomic diversity of the total phytoplankton population and the phylogenetic diversity of potential MC-producing cyanobacteria (Microcystis, Planktothrix and Anabaena during a high biomass event, and 3 compare the strains of potential MC-producers in Lake St. Clair with strains from Lake Erie and Lake Ontario. Our results demonstrated a clear predominance of cyanobacteria during a late August bloom event, primarily dominated by Microcystis, which we traced along the Lake St. Clair coastline downstream to the Detroit River's outflow at Lake Erie. Microcystin levels exceeded the Province of Ontario Drinking Water Quality Standard (1.5 µg L(-1 for safe drinking water at most sites, reaching up to five times this level in some areas. Microcystis was the predominant microcystin producer, and all toxic Microcystis strains found in Lake St. Clair were genetically similar to toxic Microcystis strains found in lakes Erie and Ontario. These findings suggest extensive genetic connectivity among the three systems.

  1. Sources

    OpenAIRE

    2015-01-01

    SOURCES MANUSCRITES Archives nationales Rôles de taille 1768/71 Z1G-344/18 Aulnay Z1G-343a/02 Gennevilliers Z1G-340/01 Ivry Z1G-340/05 Orly Z1G-334c/09 Saint-Remy-lès-Chevreuse Z1G-344/18 Sevran Z1G-340/05 Thiais 1779/80 Z1G-391a/18 Aulnay Z1G-380/02 Gennevilliers Z1G-385/01 Ivry Z1G-387b/05 Orly Z1G-388a/09 Saint-Remy-lès-Chevreuse Z1G-391a/18 Sevran Z1G-387b/05 Thiais 1788/89 Z1G-451/18 Aulnay Z1G-452/21 Chennevières Z1G-443b/02 Gennevilliers Z1G-440a/01 Ivry Z1G-452/17 Noiseau Z1G-445b/05 ...

  2. Mathematical model of heat transfer for bloom continuous casting

    Institute of Scientific and Technical Information of China (English)

    Qing Liu; Liangzhou Wang; Liqiang Zhang; Liguo Cao; Xiuzhong Ding; Mei Liang; Yongge Qi

    2008-01-01

    A mathematical model for heat transfer during solidification in continuous casting of automobile steel, was established on researching under the influence of the solidifying process of bloom quality of CCM in the EAF steelmaking shop, at Shijiazhuang Iron and Steel Co. Ltd. Several steel grades were chosen to research, such as, 40Cr and 42CrMo. According to the results of the high temperature mechanical property tests of blooms, the respective temperature curves for controlling the solidification of differem steels were acquired, and a simulating software was developed. The model was verified using two methods, which were bloom pin-shooting and surface strand temperature measuring experiments. The model provided references for research on the solidifying proc-ess and optimization of a secondary cooling system for automobile steel. Moreover, it was already applied to real production. The calculated temperature distribution and solidification trend of blooms had offered a reliable theory for optimizing the solidifying process of blooms, increasing withdrawal speed, and improving bloom quality. Meanwhile, a new secondary cooling system was designed to optimize a secondary cooling water distribution, including choice and arrangements of nozzles, calculation of cooling water quantity, and so on.

  3. Competing phytoplankton undermines allelopathy of a bloom-forming dinoflagellate.

    Science.gov (United States)

    Prince, Emily K; Myers, Tracey L; Naar, Jerome; Kubanek, Julia

    2008-12-07

    Biotic interactions in the plankton can be both complex and dynamic. Competition among phytoplankton is often chemically mediated, but no studies have considered whether allelopathic compounds are modified by biotic interactions. Here, we show that compounds exuded during Karenia brevis blooms were allelopathic to the cosmopolitan diatom Skeletonema costatum, but that bloom allelopathy varied dramatically among collections and years. We investigated several possible causes of this variability and found that neither bloom density nor concentrations of water-borne brevetoxins correlated with allelopathic potency. However, when we directly tested whether the presence of competing phytoplankton influenced bloom allelopathy, we found that S. costatum reduced the growth-inhibiting effects of bloom exudates, suggesting that S. costatum has a mechanism for undermining K. brevis allelopathy. Additional laboratory experiments indicated that inducible changes to K. brevis allelopathy were restricted to two diatoms among five sensitive phytoplankton species, whereas five other species were constitutively resistant to K. brevis allelopathy. Our results suggest that competitors differ in their responses to phytoplankton allelopathy, with S. costatum exhibiting a previously undescribed method of resistance that may influence community structure and alter bloom dynamics.

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

    Science.gov (United States)

    The Ecological Stewardship Institute at Northern Kentucky University and the U.S. Environmental Protection Agency are collaborating to optimize a harmful algal bloom detection algorithm that estimates the presence and count of cyanobacteria in freshwater systems by image analysis...

  5. Spring blooms in the Baltic Sea have weakened but lengthened from 2000 to 2014

    Science.gov (United States)

    Groetsch, Philipp M. M.; Simis, Stefan G. H.; Eleveld, Marieke A.; Peters, Steef W. M.

    2016-09-01

    Phytoplankton spring bloom phenology was derived from a 15-year time series (2000-2014) of ship-of-opportunity chlorophyll a fluorescence observations collected in the Baltic Sea through the Alg@line network. Decadal trends were analysed against inter-annual variability in bloom timing and intensity, and environmental drivers (nutrient concentration, temperature, radiation level, wind speed).Spring blooms developed from the south to the north, with the first blooms peaking mid-March in the Bay of Mecklenburg and the latest bloom peaks occurring mid-April in the Gulf of Finland. Bloom duration was similar between sea areas (43 ± 2 day), except for shorter bloom duration in the Bay of Mecklenburg (36 ± 11 day). Variability in bloom timing increased towards the south. Bloom peak chlorophyll a concentrations were highest (and most variable) in the Gulf of Finland (20.2 ± 5.7 mg m-3) and the Bay of Mecklenburg (12.3 ± 5.2 mg m-3).Bloom peak chlorophyll a concentration showed a negative trend of -0.31 ± 0.10 mg m-3 yr-1. Trend-agnostic distribution-based (Weibull-type) bloom metrics showed a positive trend in bloom duration of 1.04 ± 0.20 day yr-1, which was not found with any of the threshold-based metrics. The Weibull bloom metric results were considered representative in the presence of bloom intensity trends.Bloom intensity was mainly determined by winter nutrient concentration, while bloom timing and duration co-varied with meteorological conditions. Longer blooms corresponded to higher water temperature, more intense solar radiation, and lower wind speed. It is concluded that nutrient reduction efforts led to decreasing bloom intensity, while changes in Baltic Sea environmental conditions associated with global change corresponded to a lengthening spring bloom period.

  6. Monitoring for Harmful Algal Blooms in Influent Waters and Through Treatment on Lake Erie in the 2013 and 2014 Bloom Seasons 

    Science.gov (United States)

    Monitoring of Harmful Algal Blooms in Influent and Through Drinking Water Treatment Facilities Located on Lake Erie in the 2013 and 2014 Bloom SeasonsToby Sanan, Nicholas Dugan, Darren Lytle, Heath MashHarmful algal blooms (HABs) and their associated toxins are emerging as signif...

  7. 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)…

  8. Evaluation of Harmful Algal Bloom Outreach Activities

    Directory of Open Access Journals (Sweden)

    Richard Weisman

    2007-12-01

    Full Text Available With an apparent increase of harmful algal blooms (HABs worldwide,healthcare providers, public health personnel and coastal managers are struggling toprovide scientifically-based appropriately-targeted HAB outreach and education. Since1998, the Florida Poison Information Center-Miami, with its 24 hour/365 day/year freeAquatic Toxins Hotline (1-888-232-8635 available in several languages, has received over 25,000 HAB-related calls. As part of HAB surveillance, all possible cases of HAB-relatedillness among callers are reported to the Florida Health Department. This pilot studyevaluated an automated call processing menu system that allows callers to access bilingualHAB information, and to speak directly with a trained Poison Information Specialist. Themajority (68% of callers reported satisfaction with the information, and many provided specific suggestions for improvement. This pilot study, the first known evaluation of use and satisfaction with HAB educational outreach materials, demonstrated that the automated system provided useful HAB-related information for the majority of callers, and decreased the routine informational call workload for the Poison Information Specialists, allowing them to focus on callers needing immediate assistance and their healthcare providers. These results will lead to improvement of this valuable HAB outreach, education and surveillance tool. Formal evaluation is recommended for future HAB outreach and educational materials.

  9. Monitoring the algal bloom event in Lake Okeechobee, Florida under Tropical Cyclone Fay impacts using MODIS/Terra images

    Science.gov (United States)

    Daranpob, Ammarin; Chang, Ni-Bin; Jin, Kang-Ren; Yang, Y. Jeffrey

    2009-08-01

    Lake Okeechobee, Florida is the largest freshwater lake in the southeastern U.S. It is a key component in the hydrologic system of South Florida providing water supply for agriculture, the environment, and urban areas. Excessive phosphorus loads, from the Okeechobee watershed over the last few decades have led to increased eutrophication of this lake. Much of the excess phosphorus has been sequestered into the sediments. Sediment water interactions, including diffusive fluxes and sediment resuspension are a source of available phosphorus for phytoplankton. As a consequence, nutrient-enriched lake water has led to phytoplankton blooms from time to time. These blooms are often quantified by measurement of chlorophyll-a concentrations. While the in-situ water quality monitoring is time-consuming, sporadic, and costly, multispectral remote sensing sensors onboard satellites can detect chlorophyll-a contained in most phytoplankton efficiently. The objective of this study is to demonstrate the use of MODIS/Terra Surface Reflectance 1- Day images to capture the unique algal bloom event one week after the landfall of the hurricane Fay in mid-Sept. 2008. Use of the genetic programming model permits sound information retrieval for spatial mapping of chlorophyll-a concentrations, which help explain the mechanism as to why the algal bloom event occurred.

  10. First record of Thalassiosira curviseriata Takano (Bacillariophyta) and its bloom in the East China Sea

    Institute of Scientific and Technical Information of China (English)

    XIE Wenling; LI Yang; GAO Yahui

    2008-01-01

    A bloom caused by a diatom,Thalassiosira curviseriata Takano (Bacillariophyta),is recorded in the East China Sea for the first time in China during a red tide investigation cruise (MC2005 - 2) from 27 March to 12 April 2005.This bloom was developed with the competition of Chaetoceros debilis and Skeletonema spp.The highest cell density of T.curviseriata,which has reached 1.27 × 106 cells/dm3,was found in the surface and middle water layers of Stss ZD,ZB in the East China Sea (27.22°~29.48°N,121.53°~ 122.98°E)in early spring in 2005.During the blooming period of T.curviseriata,the population with high cell density was found in the water area with temperature of 10 ~ 15 ℃ and salinity of 29.0 ~ 33.5.The percentage of the predominant spe-cies,T.curviseriata,has reached 95.8% of total diatom cells at one time in the middle water layer.The morphological character-istics of T.curviseriata,were observed with light microscope (LM) and transmission electronic microscope (TEM).The cells are 5.0 ~ 12.6 μm in diameter,connecting each other by mucilaginous thread to form spiral and curved chains.Description and LM and TEM images of T.curviseriata are presented.T.curviseriata is ecologically characterized by eurythermy and euryhalinity,and its population variation is affected mainly by silicate,the ratios of phosphorus to silicon and nitrogen to sihcon.

  11. 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...

  12. NEACP Onboard Connectivity Study

    Science.gov (United States)

    1990-03-30

    Methodology Framework .............................. 6-3 6.2.2 Sources of ME Cost Savings with NOCH ............... 6-5 6.2.3 Additional Benefits of 1OCU...processing system (MPS) installation connects all record and data communications equipment to a common MIL -STD-1553B bus and automates many of the manual...Local Area Network Concepts A NOCH developed around a generic bus would provide connectivity throughout the aircraft, thereby reducing or eliminating

  13. Optical detection of Prorocentrum donghaiense blooms based on multispectral reflectance

    Institute of Scientific and Technical Information of China (English)

    TAO Bangyi; PAN Delu; MAO Zhihua; SHEN Yuzhang; ZHU Qiankun; CHEN Jianyu

    2013-01-01

    Prorocentrum donghaiense is one of the most common red tide causative dinoflagellates in the Changjiang (Yangtze) River Estuary and the adjacent area of the East China Sea. It causes large-scale blooms in late spring and early summer that lead to widespread ecologic and economic damage. A means for distinguish-ing dinoflagellate blooms from diatom (Skeletonema costatum) blooms is desired. On the basis of measure-ments of remote sensing reflectance [Rrs(λ)] and inherent optical parameters, the potential of using a mul-tispectral approach is assessed for discriminating the algal blooms due to P. donghaiense from those due to S. costatum. The behavior of two reflectance ratios [R1 =Rrs(560)/Rrs(532) and R2 =Rrs(708)/Rrs(665)], suggests that differentiation of P. donghaiense blooms from diatom bloom types is possible from the current band setup of ocean color sensors. It is found that there are two reflectance ratio regimes that indicate a bloom is dominated by P. donghaiense: (1) R1 >1.55 and R2 1.75 and R2 ?1.0. Various sensitivity analyses are conducted to investigate the effects of the variation in varying levels of chlorophyll concentration and colored dissolved organic matter (CDOM) as well as changes in the backscattering ratio (bbp/bp) on the efficacy of this multispectral approach. Results indicate that the intensity and inherent op-tical properties of the algal species explain much of the behavior of the two ratios. Although backscattering influences the amplitude of Rrs(λ), especially in the 530 and 560 nm bands, the discrimination between P. donghaiense and diatoms is not significantly affected by the variation of bbp/bp. Since a CDOM(440) in coastal areas of the ECS is typically lower than 1.0 m−1 in most situations, the presence of CDOM does not interfere with this discrimination, even as SCDOM varies from 0.01 to 0.026 nm−1. Despite all of these effects, the dis-crimination of P. donghaiense blooms from diatom blooms based on multispectral

  14. Thermal blooming on laser propagation in an aspirating pipe

    Science.gov (United States)

    Zhu, Fuyin; Wang, Jihong; Ren, Ge; Tan, Yufeng; Zhu, Nengbing; Ai, Zhiwei

    2016-10-01

    Thermal blooming effect of gas on laser propagation can seriously degrade performance of far-field beam quality and energy distribution. Numerical simulation is carried out to study the influences of thermal blooming on laser propagation in line pipes. A physical model of thermal blooming effect of gas on laser propagation in an aspirating pipe is established. Axial flow and suction in the outlet are used to attenuate the thermal blooming effect. Based on the computational fluid dynamics (CFD) software, stable calculation of flow field is carried out first, then the optical field and the fluent field is coupling calculated by means of user defined function (UDF). The results show that radial flow is enhanced in the aspirating pipe and the index of refraction gradient caused by thermal blooming effect is decreased. It is indicated that the beam quality of the outlet is improved compared with the pipe model without aspirating. The optical path difference (OPD) distribution of the outlet is analyzed and decomposed by Zernike polynomials. It is shown that the defocus item of 4m aspirating pipe is decreased more than an order of magnitude compared with the 4m pipe without aspirating.

  15. 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

    2017-02-23

    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. © 2017 American Association of Anatomists.

  16. Toxicity of harmful cyanobacterial blooms to bream and roach.

    Science.gov (United States)

    Trinchet, Isabelle; Cadel-Six, Sabrina; Djediat, Chakib; Marie, Benjamin; Bernard, Cécile; Puiseux-Dao, Simone; Krys, Sophie; Edery, Marc

    2013-09-01

    Aquatic ecosystems are facing increasing environmental pressures, leading to an increasing frequency of cyanobacterial Harmful Algal Blooms (cHABs) that have emerged as a worldwide concern due to their growing frequency and their potential toxicity to the fauna that threatens the functioning of ecosystems. Cyanobacterial blooms raise concerns due to the fact that several strains produce potent bioactive or toxic secondary metabolites, such as the microcystins (MCs), which are hepatotoxic to vertebrates. These strains of cyanobacteria may be potentially toxic to fish via gastrointestinal ingestion and also by direct absorption of the toxin MC from the water. The purpose of our study was to investigate toxic effects observed in fish taken from several lakes in the Ile-de-France region, where MCs-producing blooms occur. This study comprises histological studies and the measurement of MC concentrations in various organs. The histological findings are similar to those obtained following laboratory exposure of medaka fish to MCs: hepatic lesions predominate and include cell lysis and cell detachment. MC concentrations in the organs revealed that accumulation was particularly high in the digestive tract and the liver, which are known to be classical targets of MCs. In contrast concentrations were very low in the muscles. Differences in the accumulation of MC variants produced by blooms indicate that in order to more precisely evaluate the toxic potential of a specific bloom it is necessary not only to consider the concentration of toxins, but also the variants produced.

  17. Nitrogen source for uptake by Gyrodinium cf. aureolum in a tidal front

    Digital Repository Service at National Institute of Oceanography (India)

    LeCorre, P.; L'Helguen, S.; Wafar, M.V.M.

    recycling processes, or both, to sustain the bloom through its life cycle. To resolve the question of source and supply of N required for a G. aureolum bloom, we measured uptake and remineralization rates of N during such a bloom in the western English... et al. (1984) who concluded that zooplankton excretion is likely to support a fraction of the N required by G. aureolum in the English Channel. Their measurements, though, are clearly underestimates because the copepodites of Paracalanus can...

  18. Synthesis and SAR studies of 5-(pyridin-4-yl)-1,3,4-thiadiazol-2-amine derivatives as potent inhibitors of Bloom helicase

    DEFF Research Database (Denmark)

    Rosenthal, Andrew S; Dexheimer, Thomas S; Gileadi, Opher;

    2013-01-01

    complementary strands of duplex DNA as well as atypical DNA structures such as Holliday junctions. Mutations of the BLM gene can result in Bloom syndrome, an autosomal recessive disorder associated with cancer predisposition. BLM-deficient cells exhibit increased sensitivity to DNA damaging agents indicating...... and related analogs, which possess potent BLM inhibition and exhibit selectivity over related helicases. Moreover, these compounds demonstrated cellular activity by inducing sister chromatid exchanges, a hallmark of Bloom syndrome.......Human cells utilize a variety of complex DNA repair mechanisms in order to combat constant mutagenic and cytotoxic threats from both exogenous and endogenous sources. The RecQ family of DNA helicases, which includes Bloom helicase (BLM), plays an important function in DNA repair by unwinding...

  19. Harmful Algal Bloom in Iligan Bay, Southern Philippines

    Directory of Open Access Journals (Sweden)

    Helen J Vicente

    2002-12-01

    Full Text Available We report the first occurrence of harmful algal bloom (HAB caused by a non-toxic dinoflagellate, Cochlodinium sp. in Philippine waters, particularly, in Kalangahan Pt.-Manticao Pt., Iligan Bay on March 13-18, 2002. Two patches of Cochlodinium sp. bloom, associated with fish kills in Kalangahan Pt.-Mantacao Pt., Iligan Bay, caused localized water discoloration from the usual ocean blue to rusty brown or reddish brown to blackish. The first patch, located near fish-aggregating device (FAD areas, spanned 2 km wide, while the second patch, located near a fish corral, spanned 500m wide. These patches occupied the water column from surface to 5 m depth, but a thick mat formed at 0.5 m to surface. Patches occupied the water column from surface to 5 m depth, but a thick mat formed at 0.5 m to surface. Patches decreased as the bloom began to decline. The observed dead demersal and pelagic fishes coincided with highest bloom density of 3.1 x 104 to 3.8 x 104 cells ml-1 of Cochlodinium. Dissected gills and stomach contents of fishes killed in HAB-affected areas did not reveal any indication of clogging of gills by Cochlodinium sp. Fishes covered by the “shading effect” of Cochlodinium bloom may have suffered anoxia or asphyxation due to oxygen depletion. No poisoning of people who consumed the dead fishes was reported. Laboratory analyses revealed lower DO values, 2.4 to 0.5 mg L-1from 2400 to 0600Hr; 14N:1P ratio; air-water temperature ranged from 28-29°C; pH 7.89-8.29; and salinity, 33-35°/oo. Favella sp., a tintinnid grazer of dinoflagellate was developing in the area at the termination of the Cochlodinium bloom on March 18.

  20. FANCM: A Landing Pad for the Fanconi Anemia and Bloom's Syndrome Complexes

    OpenAIRE

    Vinciguerra, Patrizia; D'Andrea, Alan D.

    2009-01-01

    Here, Deans and West (2009) reveal the molecular basis of the phenotypic similarities between Fanconi Anemia (FA) and Bloom's Syndrome, identifying FANCM as the anchor for both FA and Bloom's complexes at the site of the DNA interstrand crosslink.

  1. About Connections

    Directory of Open Access Journals (Sweden)

    Kathleen S Rockland

    2015-05-01

    Full Text Available Despite the attention attracted by connectomics, one can lose sight of the very real questions concerning What are connections? In the neuroimaging community, structural connectivity is ground truth and underlying constraint on functional or effective connectivity. It is referenced to underlying anatomy; but, as increasingly remarked, there is a large gap between the wealth of human brain mapping and the relatively scant data on actual anatomical connectivity. Moreover, connections have typically been discussed as pairwise, point x projecting to point y (or: to points y and z, or more recently, in graph theoretical terms, as nodes or regions and the interconnecting edges. This is a convenient shorthand, but tends not to capture the richness and nuance of basic anatomical properties as identified in the classic tradition of tracer studies. The present short review accordingly revisits connectional weights, heterogeneity, reciprocity, topography, and hierarchical organization, drawing on concrete examples. The emphasis is on presynaptic long-distance connections, motivated by the intention to probe current assumptions and promote discussions about further progress and synthesis.

  2. [Causes of jellyfish blooms and their influence on marine environment].

    Science.gov (United States)

    Qu, Chang-feng; Song, Jin-ming; Li, Ning

    2014-12-01

    Jellyfish blooms have damaged the normal composition and function of marine ecosystem and ecological environments, which have been one of the new marine ecological disasters. In this study, we summarized the possible inducements of jellyfish blooms, and the influences of jellyfish blooms on biogenic elements, dissolved oxygen, seawater acidity and biological community were discussed emphatically. The results showed that jellyfish blooms had a close contact with its physiological structure and life history, which had favorable characteristics including simple body struc- ture, rapid growth, thriving reproduction and short generation interval to tolerate harsh environment better. Jellyfish abundance increased rapidly when it encountered suitable conditions. The temperature variations of seawater might be the major inducing factor which could result in jellyfish blooms. Jellyfish blooms may benefit from warmer temperature that could increase the food availability of jellyfish and promote jellyfish reproduction, especially for warm temperate jellyfish species. Eutrophication, climate change, overfishing, alien invasions and habitat modification were all possible important contributory factors of jellyfish blooms. Jellyfish could significantly influence the form distribution and biogeochemical cycling of biogenic elements. Jellyfish excreted NH4+ and P04(3-) at a rate of 59.1-91.5 micromol N x kg(-1) x h(-1) and 1.1-1.8 micromol P x kg(-1) x h(-1), which could meet about 8%-10% and 21.6% of the phytoplankton primary production requirement of N and P, respectively. Live jellyfish released dissolved organic carbon (DOC) at a rate of 1.0 micromol C x g(-1) x d(-1). As jellyfish decomposing, the effluxes of total N and total P were 4000 micromol N x kg(-1) x d(-1) and 120 micromol P x kg(-1) x d(-1), respectively, while the efflux of DOC reached 30 micromol C x g(-1) x d(-1). Jellyfish decomposition could cause seawater acidification and lowered level of dissolved oxygen

  3. The cognitive context of examinations in psychiatry using Bloom's taxonomy.

    Science.gov (United States)

    Miller, D A; Sadler, J Z; Mohl, P C; Melchiode, G A

    1991-11-01

    Psychiatric practice involves complex thinking patterns. In addition to commanding a huge number of facts, the student must learn to manipulate factual knowledge to solve diagnostic problems, develop treatment plans, and critically evaluate those plans. This study demonstrates an empirical method for evaluating the level of cognitive processes tested in multiple choice examinations. Use of Bloom's taxonomy in evaluating test items demonstrated the majority of test items on a psychiatry clerkship examination and a resident in-training examination fell into the most basic cognitive level, that of simple recall. The utility of Bloom's taxonomy is discussed along with implications for medical education.

  4. Gendered Connections

    DEFF Research Database (Denmark)

    Jensen, Steffen Bo

    2009-01-01

    This article explores the gendered nature of urban politics in Cape Town by focusing on a group of female, township politicians. Employing the Deleuzian concept of `wild connectivity', it argues that these politically entrepreneurial women were able to negotiate a highly volatile urban landscape...... space also drew on quite traditional notions of female respectability. Furthermore, the article argues, the form of wild connectivity to an extent was a function of the political transition, which destabilized formal structures of gendered authority. It remains a question whether this form...... of connectivity might endure, as Capetonian politics assumes a post-apartheid structure....

  5. Phytoplankton of the Swan-Canning Estuary: a comparison of nitrogen uptake by different bloom assemblages

    Science.gov (United States)

    Horner Rosser, S. M. J.; Thompson, Peter A.

    2001-09-01

    Spring chlorophyte-, summer dinophyte- and autumn cryptophyte-dominated phytoplankton blooms occurring in the upper reaches of the Swan-Canning Estuary have been studied to compare species composition and diurnal distribution and to determine preferential uptake rates for different nitrogen sources. Species distribution patterns over diurnal cycles showed dinophyte and cryptophyte species exhibiting diurnal vertical migration patterns which changed over a three-week bloom period. The dinophyte and cryptophyte behaviour appeared to be related to measured changes in ambient nitrogen profiles over the course of the bloom. Chlorophyte species were not shown to be strongly migratory over diurnal periods. Absolute uptake rates (, approximating Pmax) for nitrogen, in the form of 15NO3-, 15NH4+ or 15N-urea, were compared between seasonal bloom assemblages and ranged between 0·02 and 12 µg N l-1 h-1 (NO3 0·02-7; NH4 0·4-9; urea 0·1-12 µg N l-1sources were implicated in supporting these blooms. Results indicated no physiological preference at any depth for NO

  6. Improving retouched Bloom filter for trading off selected false positives against false negatives

    OpenAIRE

    Donnet, Benoît; Baynat, Bruno; Friedman, Timur

    2010-01-01

    Where distributed agents must share voluminous set membership information, Bloom fil- ters provide a compact, though lossy, way for them to do so. Numerous recent networking papers have examined the trade-offs between the bandwidth consumed by the transmis- sion of Bloom filters, and the error rate, which takes the form of false positives. This paper is about the retouched Bloom filter (RBF). An RBF is an extension that makes the Bloom fil- ter more flexible by permitting the removal of false...

  7. Retouched Bloom Filters: Allowing Networked Applications to Flexibly Trade Off False Positives Against False Negatives

    OpenAIRE

    Donnet, Benoît; Baynat, Bruno; Friedman, Timur

    2006-01-01

    Where distributed agents must share voluminous set mem- bership information, Bloom filters provide a compact, though lossy, way for them to do so. Numerous recent networking papers have examined the trade-offs between the bandwidth consumed by the transmission of Bloom filters, and the er- ror rate, which takes the form of false positives, and which rises the more the filters are compressed. In this paper, we introduce the retouched Bloom filter (RBF), an extension that makes the Bloom filter...

  8. HR Connect

    Data.gov (United States)

    US Agency for International Development — HR Connect is the USAID HR personnel system which allows HR professionals to process HR actions related to employee's personal and position information. This system...

  9. The relationship between volatile halocarbons and phytoplankton pigments during a Trichodesmium bloom in the coastal eastern Arabian Sea

    Science.gov (United States)

    Roy, Rajdeep; Pratihary, Anil; Narvenkar, Gayatree; Mochemadkar, Sunita; Gauns, Mangesh; Naqvi, S. W. A.

    2011-11-01

    Eukaryotic phytoplankton such as diatoms and prymnesiophytes produce biogenic halocarbons in the ocean that serve as important sources of chlorine and bromine to the atmosphere, but the role of cyanobacteria in halocarbon production is not well established. We studied distributions of chloroform (CHCl 3), carbon tetrachloride (CCl 4), methylene bromide (CH 2Br 2) and bromoform (CHBr 3) in relation to phytoplankton composition, determined from pigment analysis complemented by microscopic examination, for one month in coastal waters of the eastern Arabian that experienced a Trichodesmium bloom that typically occurs during the Spring Intermonsoon season. High concentrations of zeaxanthin (23 μg l -1), alpha beta betacarotene (6 μg l -1) and chlorophyll a (67 μg l -1) were found within the bloom whereas the marker pigment concentrations were low outside the bloom. CHCl 3 and CCl 4 occurred in relatively high concentrations in surface waters whereas CH 2Br 2 and CHBr 3 were restricted to the subsurface layer. Chlorinated halocarbons were positively inter-correlated and with CHBr 3. The observed spatial and temporal trends in brominated compounds appear to be related to the abundance of Trichodesmium although correlations between concentrations of brominated compounds with various marker pigments were poor and statistically non-significant. The results support the existence of multiple sources and sinks of halogenated compounds, which might obscure the relationship between halocarbons and phytoplankton composition.

  10. Return bloom in 'Stayman' apple with NAA and/or ethephon: 2007 through 2009

    Science.gov (United States)

    Following a season in which apple trees produce a full crop, many cultivars fail to produce enough bloom the next year for an adequate crop. Obtaining good return bloom is a problem for many apple growers. Plant growth regulators (PGRs) are recommended to enhance return bloom in apple. This study...

  11. 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…

  12. Energy storage connection system

    Science.gov (United States)

    Benedict, Eric L.; Borland, Nicholas P.; Dale, Magdelena; Freeman, Belvin; Kite, Kim A.; Petter, Jeffrey K.; Taylor, Brendan F.

    2012-07-03

    A power system for connecting a variable voltage power source, such as a power controller, with a plurality of energy storage devices, at least two of which have a different initial voltage than the output voltage of the variable voltage power source. The power system includes a controller that increases the output voltage of the variable voltage power source. When such output voltage is substantially equal to the initial voltage of a first one of the energy storage devices, the controller sends a signal that causes a switch to connect the variable voltage power source with the first one of the energy storage devices. The controller then causes the output voltage of the variable voltage power source to continue increasing. When the output voltage is substantially equal to the initial voltage of a second one of the energy storage devices, the controller sends a signal that causes a switch to connect the variable voltage power source with the second one of the energy storage devices.

  13. Thirty years - Alexandrium fundyense cyst, bloom dynamics and shellfish toxicity in the Bay of Fundy, eastern Canada

    Science.gov (United States)

    Martin, Jennifer L.; LeGresley, Murielle M.; Hanke, Alex R.

    2014-05-01

    Sediment and water samples were collected for Alexandrium fundyense spatial and temporal distribution and abundance at more than 120 locations throughout the Bay of Fundy during the summers and winters of 1980-1984. These broad surveys have been repeated at various times through the past 30 years, with more regular sampling since 2004. In addition, A. fundyense abundance has been monitored at several locations within the Bay of Fundy at weekly intervals from April to November and monthly during the remaining months since 1988. Paralytic Shellfish Poisoning (PSP) toxins in shellfish (notably Mya arenaria) have also been monitored at multiple locations in the Bay of Fundy since 1943. The datasets were examined to determine relationships and roles between overwintering resting cysts, bloom initiation, bloom decline, motile cell dispersal and A. fundyense motile populations and resulting shellfish toxicity since 1980. Cysts are widely dispersed throughout the Bay of Fundy in the offshore, inshore and intertidal zones with the largest deposits located in the offshore in silt/clay sediments to the east and north of Grand Manan Island at depths of 60-180 m. Results show that there is a constant stable source of cysts in the Bay of Fundy with highest concentrations of cysts (9780 cysts cm-3) observed in 2010 and highest concentrations of A. fundyense motile cells (18×106 cells L-1) observed in 1980. Interannual changes in abundance in A. fundyense populations, resting cysts and the temporal trends in M. arenaria toxicity are discussed. Results show that there was no relationship between the abundance of overwintering cysts and the magnitude of A. fundyense blooms. The offshore seed beds appear to be relatively constant in cyst density among most years and serve as an important source for the motile cells that lead to initiation of major blooms and resulting shellfish toxicity throughout the Bay of Fundy.

  14. ENCLOSURE EXPERIMENTS ON AND LACUSTRINE PRACTICE FOR ELIMINATING MICROCYSTIS BLOOM

    Institute of Scientific and Technical Information of China (English)

    刘建康; 谢平

    2002-01-01

    Microcystis bloom, one of the most objectionable characteristics of eutrophication in tropical and subtropical waters, occurred in Donghu Lake (East Lake) of Wuhan every summer from the 1970s up to 1984, but from 1985 up tonow failed to occur there. The cause of its disappearance remained in obscurityuntil recently. In situ enclosure experiments in the lake for three years showed that the stocking of the filter-feeding silver carp (Hypophthalmichthys molitrix) and big-head carp (Aristichthys nobilis) played a decisive role in eliminating Microcystis bloom from the lake; but that recurrence of the bloom is possibleunder certain conditions. This paper presents the details and the results of enclosure experiments. The authors' analysis of fish biomass data obtained by echo-sounding and the fishery production of the lake over the years, revealed that the recurrence of Microcystis bloom can be prevented so long as the combined biomass of silver carp and big-head carp remains at or exceeds 50 g per cubic meter of lakewater, as was the case in the lake's 1985 fish yield of 1015 t.``

  15. Dynamic Soft Reduction for Continuously Cast Rail Bloom

    Institute of Scientific and Technical Information of China (English)

    CHEN Yong; LI Gui-jun; YANG Su-bo; ZHU Miao-yong

    2007-01-01

    Center porosity and centerline segregation in continuously cast bloom can be minimized by the well-known method of dynamic soft reduction. Metallurgical results of soft reduction previously employed in continuous bloom casting for heavy rail steel in Panzhihua Iron and Steel Group were not fully achieved because of the improper soft reduction process. Therefore, experiments for optimizing the process parameters of soft reduction for bloom were carried out. The results show that the proportion of the center porosity, which is less than 1.0, increases from 28.41% to 99.81%, while the proportion of the centerline segregation class increases from 40.91% to 100%, and the proportion of the central cavity increases from 92.05% to 100%, whereas the center carbon segregation index decreases from 1.17 to 1.05. The internal quality and the mechanical performance of the rails produced from continuously cast blooms meet the requirement of high-speed tracks of 350 km/h.

  16. Allelopathic control of cyanobacterial blooms by periphyton biofilms.

    Science.gov (United States)

    Wu, Yonghong; Liu, Jiantong; Yang, Linzhang; Chen, Hong; Zhang, Shanqing; Zhao, Huijun; Zhang, Naiming

    2011-03-01

    Periphyton biofilms are natural mixtures comprised of photoautotrophic and heterotrophic complex microorganisms. In this work, the inhibition effects of periphyton biofilms on cyanobacterial blooms were studied in pilot and field trials. Results show that the cyanobacterial species responsible for the blooms had an upper nutrient concentration threshold, below which it could not effectively compete with other organisms in the periphyton. The disappearance of the cyanobacterial blooms was due to the allelopathy between the cyanobacteria and periphyton biofilm. In particular, it was found that the periphyton biofilm could produce water-soluble allelochemicals such as indole and 3-oxo-α-ionone to significantly inhibit the growth of the cyanobacteria. These allelochemicals are able to damage the thylakoid membranes of the cyanobacteria, interrupt the electron transport in photosystem II, decrease effective quantum yields, and eventually lead to the failure of photosynthesis. A comprehensive discussion on the ecological consequences of these findings is also presented. This work demonstrates the potential of periphyton biofilm to be used as an environmentally friendly ecological engineering solution for (i) the control of cyanobacterial blooms and (ii) a transitional means for the construction of beneficial conditions for ecosystem restoration. In addition, this work provides significant insights into the competitive relationships between algae and biofilms.

  17. Controlling eutrophication by combined bloom precipitation and sediment phosphorus inactivation

    NARCIS (Netherlands)

    Lürling, M.F.L.L.W.; Oosterhout, J.F.X.

    2013-01-01

    The hypothesis that the combination of the flocculent polyaluminium chloride (PAC) with the lanthanum-modified bentonite Phoslock® (Flock & Lock) could sink effectively a water bloom of cyanobacteria and could shift a turbid, cyanobacteria infested lake to a clear water lake was tested in a cont

  18. 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.

  19. Using Bloom To Bridge the WAC/WID Divide.

    Science.gov (United States)

    Cross, Geoffrey; Wills, Katherine

    A longitudinal study combined Stephen Tsuchdi's Workaday activities with Bloom's taxonomy of educational objectives to bridge the WAC/WID (writing across the curriculum/writing in the disciplines) divide. The researchers hoped that by combining concrete activities that can be applied across disciplines with a Bloomian conceptual framework of…

  20. Reconsidering Bloom's Taxonomy of Educational Objectives, Cognitive Domain.

    Science.gov (United States)

    Moore, David S.

    1982-01-01

    The hierarchical structure of the cognitive domain presented in Benjamin S. Bloom's taxonomy of educational objectives does not reflect the actual nature of the learning process. Attempts to apply the classification levels to student learning in mathematics and other subjects place the taxonomy's usefulness in question. (PP)

  1. 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…

  2. 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…

  3. Was Bloom's Taxonomy Pointed in the Wrong Direction?

    Science.gov (United States)

    Wineburg, Sam; Schneider, Jack

    2010-01-01

    Bloom's Taxonomy usually is depicted as a pyramid with knowledge at the lowest level and evaluation at the top. For the history classroom, however, that arrangement might be upside down. In history, evaluation is often necessary before new knowledge can be learned. (Contains 1 figure.)

  4. Using Bloom's Taxonomy to Teach Students about Plagiarism

    Science.gov (United States)

    Vosen, Melissa A.

    2008-01-01

    Melissa A. Vosen outlines a unit she has designed to help students comprehend the often unclear boundaries and issues surrounding plagiarism. Using Bloom's taxonomy of the cognitive domain, students complete increasingly complex tasks, learning to construct a works cited page and assess scholarly opinions. They also research the consequences of…

  5. Conception of Learning Outcomes in the Bloom's Taxonomy Affective Domain

    Science.gov (United States)

    Savickiene, Izabela

    2010-01-01

    The article raises a problematic issue regarding an insufficient base of the conception of learning outcomes in the Bloom's taxonomy affective domain. The search for solutions introduces the conception of teaching and learning in the affective domain as well as presents validity criteria of learning outcomes in the affective domain. The…

  6. 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. 

  7. Using LANDSAT to expand the historical record of phytoplankton blooms in Lake Erie

    Science.gov (United States)

    Ho, J. C.; Michalak, A. M.; Stumpf, R. P.; Bridgeman, T. B.

    2014-12-01

    Freshwater harmful algal blooms are occurring with increasing frequency worldwide, intensifying the need for deeper understanding of the processes driving bloom formation. Such understanding is a prerequisite for developing management strategies for limiting bloom occurrence. Unfortunately, however, data for developing robust predictive models of bloom formation are lacking. Even in the well-studied Lake Erie, where diatom and cyanobacteria blooms have occurred for several decades in the Western Basin, previous in-situ and remote-sensing data collection efforts have been hampered by spatial and temporal sampling limitations, resulting in a sparse historical record. Leveraging available data to expand the historical record of algal blooms would thus make it possible to better evaluate hypotheses about factors influencing bloom formation. In this work, remotely-sensed observations of phytoplankton obtained using LANDSAT imagery are presented for 1984-2011. Several phytoplankton detection algorithms based on LANDSAT 5 imagery are evaluated during the period also covered by MERIS (2002-2011), which offers a relatively detailed assessment of bloom occurrence over the last decade. The best algorithm is then applied to historical LANDSAT data, and results are used to obtain new information about historical conditions and assess implications for developing improved models of bloom formation. Estimates of historical bloom occurrence and bloom seasonality shed new light on the widely-held view that phosphorus controls and invasive mussels resulted in substantial bloom reductions in the early 1990s. The new estimated records are not consistent with limited in-situ phytoplankton measurements from that period, and provide additional information on bloom occurrence during years with little to no supporting literature. This work demonstrates the potential to unearth new insights about historical phytoplankton blooms in Lake Erie, as well as in freshwater lakes broadly, and is a

  8. Airborne Hyperspectral Sensing of Monitoring Harmful Algal Blooms in the Great Lakes Region: System Calibration and Validation

    Science.gov (United States)

    Lekki, John; Anderson, Robert; Avouris, Dulcinea; Becker, RIchard; Churnside, James; Cline, Michael; Demers, James; Leshkevich, George; Liou, Larry; Luvall, Jeffrey; Ortiz, Joseph; Royce, Anthony; Ruberg, Steve; Sawtell, Reid; Sayers, Michael; Schiller, Stephen; Shuchman, Robert; Simic, Anita; Stuart, Dack; Sullivan, Glenn; Tavernelli, Paul; Tokars, Roger; Vander Woude, Andrea

    2017-01-01

    institutions as well as one in South Dakota and one in Alabama, this effort was able to provide next-day georeferenced estimates of cyanobacteria and scum concentrations. Very prompt processing and analysis of the hyperspectral imagery is necessary for the information to be acted upon. For example, a next-day report of an overflight over the Ohio River indicated that a bloom could be present as far downstream as the Cincinnati intake, but the Ohio EPA had not received visual reports of a bloom that far downstream. Water samples were obtained at the Cincinnati water intake, based on the flight data, and detected microcystins in the source water. The flight data helped State and municipal authorities realize the potential extent of that bloom, and triggered response sampling, before the visual river-wide scums started forming. The present document describes the process that was utilized to take raw remote sensing data and create information products; this includes system calibration and validation, efforts to correct atmospheric effects, and algorithms that produce the data products. Furthermore, successful research into improved algorithms for expanding the capability to delineate in water constituents is included. Finally, comparisons that show expected relationships between ground-based measurements and hyperspectral imager version 2 (HSI2) data results are presented, giving confidence in the remote sensing products.

  9. Skill assessment for an operational algal bloom forecast system

    Science.gov (United States)

    Stumpf, Richard P.; Tomlinson, Michelle C.; Calkins, Julie A.; Kirkpatrick, Barbara; Fisher, Kathleen; Nierenberg, Kate; Currier, Robert; Wynne, Timothy T.

    2010-01-01

    An operational forecast system for harmful algal blooms (HABs) in southwest Florida is analyzed for forecasting skill. The HABs, caused by the toxic dinoflagellate, Karenia brevis, lead to shellfish toxicity and to respiratory irritation. In addition to predicting new blooms and their extent, HAB forecasts are made twice weekly during a bloom event, using a combination of satellite derived image products, wind predictions, and a rule-based model derived from previous observations and research. These forecasts include: identification, intensification, transport, extent, and impact; the latter being the most significant to the public. Identification involves identifying new blooms as HABs and is validated against an operational monitoring program involving water sampling. Intensification forecasts, which are much less frequently made, can only be evaluated with satellite data on mono-specific blooms. Extent and transport forecasts of HABs are also evaluated against the water samples. Due to the resolution of the forecasts and available validation data, skill cannot be resolved at scales finer than 30 km. Initially, respiratory irritation forecasts were analyzed using anecdotal information, the only available data, which had a bias toward major respiratory events leading to a forecast accuracy exceeding 90%. When a systematic program of twice-daily observations from lifeguards was implemented, the forecast could be meaningfully assessed. The results show that the forecasts identify the occurrence of respiratory events at all lifeguard beaches 70% of the time. However, a high rate (80%) of false positive forecasts occurred at any given beach. As the forecasts were made at half to whole county level, the resolution of the validation data was reduced to county level, reducing false positives to 22% (accuracy of 78%). The study indicates the importance of systematic sampling, even when using qualitative descriptors, the use of validation resolution to evaluate forecast

  10. Connected Traveler

    Energy Technology Data Exchange (ETDEWEB)

    2016-06-01

    The Connected Traveler framework seeks to boost the energy efficiency of personal travel and the overall transportation system by maximizing the accuracy of predicted traveler behavior in response to real-time feedback and incentives. It is anticipated that this approach will establish a feedback loop that 'learns' traveler preferences and customizes incentives to meet or exceed energy efficiency targets by empowering individual travelers with information needed to make energy-efficient choices and reducing the complexity required to validate transportation system energy savings. This handout provides an overview of NREL's Connected Traveler project, including graphics, milestones, and contact information.

  11. Wintertime pytoplankton bloom in the Subarctic Pacific supportedby continental margin iron

    Energy Technology Data Exchange (ETDEWEB)

    Lam, Phoebe J.; Bishop, James K.B.; Henning, Cara C.; Marcus,Matthew A.; Waychunas, Glenn A.; Fung, Inez

    2004-06-08

    Heightened biological activity was observed in February 1996in the high-nutrient low-chlorophyll (HNLC) subarctic North PacificOcean, a region that is thought to beiron-limited. Here we provideevidence supporting the hypothesis that Ocean Station Papa (OSP) in thesubarctic Pacific received a lateral supply of particulate iron from thecontinental margin off the Aleutian Islands in the winter, coincidentwith the observed biological bloom. Synchrotron X-ray analysis was usedto describe the physical form, chemistry, and depth distributions of ironin size fractionated particulate matter samples. The analysis revealsthat discrete micron-sized iron-rich hotspots are ubiquitous in the upper200m at OSP, more than 900km from the closest coast. The specifics of thechemistry and depth profiles of the Fe hot spots trace them to thecontinental margins. We thus hypothesize that iron hotspots are a markerfor the delivery of iron from the continental margin. We confirm thedelivery of continental margin iron to the open ocean using an oceangeneral circulation model with an iron-like tracer source at thecontinental margin. We suggest that iron from the continental marginstimulated a wintertime phytoplankton bloom, partially relieving the HNLCcondition.

  12. Groundwater contamination by microcystin from toxic cyanobacteria blooms in Lake Chaohu, China.

    Science.gov (United States)

    Yang, Zhen; Kong, Fanxiang; Zhang, Min

    2016-05-01

    Lake Chaohu is a eutrophic lake that experiences massive cyanobacterial blooms. The high concentrations of microcystin observed in this lake are the result of the bloom's high proportion of toxic cyanobacteria strains. Groundwater is the important source of water for drinking, washing, and irrigation in the watershed of Lake Chaohu. This study examines the space-time distribution of microcystins and related environmental factors in wells near Lake Chaohu. All collected groundwater samples from the Lake Chaohu region had detectable concentrations of microcystins. The highest concentration of microcystins, 1.07 μg L(-1), occurred in a well hundreds of meters from the western coast of the lake in September. The distance from the lake shore to the well was significantly and positively correlated with the microcystin concentration in the groundwater. Moreover, a correlation analysis shows that the microcystin concentration in the groundwater was positively correlated with the total dissolved phosphorus (TDP) and microcystin concentration of the nearby lake water. Therefore, the microcystin in the groundwater likely originates from penetration by nearby lake water. Our results suggest that the groundwater near Lake Chaohu poses a significant health risk for the local residents when used for drinking water.

  13. Electrical source imaging and connectivity analysis to localize the seizure-onset zone based on high-density ictal scalp EEG recordings

    OpenAIRE

    Staljanssens, Willeke; Strobbe, Gregor; Van Holen, Roel; Birot, Gwenael; Michel, Christophe; Seeck, Margitta; Vulliémoz, Serge; van Mierlo, Pieter

    2015-01-01

    Functional connectivity analysis of ictal intracranial EEG (icEEG) recordings can help with seizure-onset zone (SOZ) localization in patients with focal epilepsy1. However, it would be of high clinical value to be able to localize the SOZ based on non-invasive ictal EEG recordings to better target or avoid icEEG and improve surgical outcome. In this work, we propose an approach to localize the SOZ based on non-invasive ictal high- density EEG (hd-EEG) recordings. We considered retrospectiv...

  14. Learning Connections

    Science.gov (United States)

    Royer, Regina D.; Richards, Patricia O.

    2005-01-01

    In this edition of Learning Connections, the authors show how technology can enhance study of weather patterns, reading comprehension, real-world training, critical thinking, health education, and art criticism. The following sections are included: (1) Social Studies; (2) Language Arts; (3) Computer Science and ICT; (4) Art; and (5) Health.…

  15. Getting Connected

    Science.gov (United States)

    Larkin, Patrick

    2011-01-01

    That the world outside schools is changing faster than ever is old news. Unfortunately, that the world "inside" schools is changing at a glacial pace is even older news. As school leaders, principals have an important choice to make as they move into the second decade of the 21st century. School leaders have a moral obligation to connect and…

  16. 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

  17. In situ observation of harmful dinoflagellate bloom in the eastern coast of Kyushu, Japan

    Science.gov (United States)

    Yamaguchi, Hisashi; Murakami, Hirishi; Miyamura, Kazuyoshi; Siawanto, Eko; Kobayashi, Hiroshi; Ishizaka, Joji

    2014-05-01

    Oita coast, where is in the eastern coast of Kyushu, Japan, is a richly fish aquaculture area. However, sometimes harmful algal blooms occur in this region, especially harmful dinoflagellates blooms, and cultured fish mortality occurs. Ocean color remote sensing is expected as a useful tool to reduce the financial damage of harmful algal blooms. However, ocean color data is low accuracy in the coastal region because colored dissolved organic matter and suspended solid are dominant. More optical data of harmful algal blooms are required because there are few data in harmful algal blooms. The field observation was conducted to understand the inherent optical property of harmful dinoflagellate bloom in the eastern coast of Oita prefecture on April and August 2013. Chlorophyll-a maximum (>24 mg m^-3) was observed in the subsurface layer on April 2013. The dominant phytoplankton species in this chlorophyll-a maximum layer was dinoflagellate Cochlodinium polykrikoides (>300 cells ml^-1) and early stage of the bloom was formed. Peak of the remote sensing reflectance was near 565nm due to strong phytoplankton absorption within 400 ~ 500 nm domain from the subsurface bloom layer. Moreover, high phytoplankton absorption coefficient was observed at the shorter wavelength (bloom was detected by using dinoflagellate bloom detection algorithm, which is a simpler new satellite remote sensing-based harmful algal blooms detection method for JAXA's GCOM-C/SGLI (Siswanto et al., 2013). However, detection of the dinoflagellate Karenia mikimotoi bloom by using the algorithm on August 2013 was difficult as colored dissolved organic matter and detritus absorptions were high. Although the algorithm could detect the early stage of C. polycrikoides bloom, the algorithm improvement to detect the harmful algal blooms in the case II water is thus highly required. This research is part of the combined research between Japan Aerospace Exploration Agency and National Research Institute of

  18. Order-theoretical connectivity

    Directory of Open Access Journals (Sweden)

    T. A. Richmond

    1990-01-01

    Full Text Available Order-theoretically connected posets are introduced and applied to create the notion of T-connectivity in ordered topological spaces. As special cases T-connectivity contains classical connectivity, order-connectivity, and link-connectivity.

  19. Estimating the Budgets of Nutrients for Phytoplankton Bloom in the Central Yellow Sea Using a Modified Lower Tropic Ecosystem Model

    Institute of Scientific and Technical Information of China (English)

    YUAN Chengyi; WANG Yuheng; WEI Hao

    2014-01-01

    A modified lower trophic ecosystem model (NEMURO) is coupled with a three-dimensional hydrodynamic model for an application in the central Yellow Sea. The model is used to simulate the horizontal distributions and annual cycles of chlorophyll-a and nutrients with results consistent with historical observations. Generally, during the winter background and spring bloom periods, the exchange with neighboring waters constitutes the primary sources of nutrients. Howerver, during the winter background period, the input of silicate from the layer deeper than 50 m is the most important source that contributes up to 60%to the total sources. Dur-ing the spring bloom period, the transport across the thermocline makes significant contribution to the input of phosphate and silicate. During the post spring bloom period, the relative contribution of relevant processes varies for different nutrients. For ammonium, atmospheric deposition, excretion of zooplankton and decomposition of particulate and dissolved nitrogen make similar contributions. For phosphate and silicate, the dominant input is the transport across the thermocline, accounting for 62% and 68% of the total sources, respectively. The N/P ratio averaged annually and over the whole southern Yellow Sea is up to 51.8, indicating the potential of P limitation in this region. The important influence of large scale sea water circulation is revealed by both the estimated fluxes and the corresponding N/P ratio of nutrients across a section linking the northeastern bank of the Changjiang River and Cheju Island. During the winter background period, the input of nitrate, ammonium, phosphate and silicate by the Yellow Sea Warm Current is estimated to be 4.6×1010, 2.3×1010, 2.0×109 and 1.2×1010 mol, respectively.

  20. Response of Harmful Algal Blooms to Environmental Changes in Daya Bay, China

    Directory of Open Access Journals (Sweden)

    Jing Yu

    2007-01-01

    Full Text Available Economic progress has been rapid around the Daya Bay region of the northern South China Sea (SCS over recent decades. To investigate changes of Harmful Algal Blooms (HABs caused by environmental situation in the bay area, the present study analyzed the occurrence of HAB and environmental conditions in Daya Bay using in situ and satellite remote sensing data for the period of 1983 - 2004. Only 14 HABs were observed during the first decade (1983 - 1993, while 55 HABs occurred during the second decade (1994 - 2004. The locations of HAB have extended from aquaculture areas to the entire bay area. In addition, the seasonality of HAB has changed from spring and autumn prior to 1994 to all year round post 1994. Changes in HAB frequency and location were found to be associated with variations in nutrients and contaminants in the bay area. Total inorganic nitrogen (TIN was 0.021 mg l -1 in 1986, but had reached 0.068 mg l -1 by 1999 and the ratio of TIN/P increased also, with a peak value (18.28 in 1999. Organic contaminants have also been relatively high in recent years in Daya Bay. The seasonal extension of HAB was found to be connected partially with increased water temperature resulting from the thermal discharge of nuclear power stations. Yearly mean water surface temperature (WST increased over the past two decades. Monthly mean WST also increased after the Daya Bay nuclear power station commenced operating in 1994, ranging from 0.2 to 2.7¢XC. There were about 14 algal species recorded to have caused HABs frequently in Daya Bay, such as Scrippsiella trochoidea. The number of HAB species increased in the second decade (1994 - 2004. A warm-water favoring species Peridinium quinquecorne caused a bloom in May 1999. This was the first recorded time of this species blooming in China. These changes are associated with increases in cage aquaculture, contaminants discharged from industrial and agricultural activities, and thermal discharge from the nuclear

  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...

  2. On the "hidden" phytoplankton blooms on Australia's southern shelves

    Science.gov (United States)

    Kämpf, Jochen; Kavi, Ankit

    2017-02-01

    Phytoplankton blooms on Australia's southern shelves are revisited using satellite-derived monthly data of chlorophyll a concentrations for the period 2003-2015. It is known that the region hosts a seasonal coastal upwelling system that develops in austral summer (January-March) with chlorophyll a concentrations of >2 mg/m3. While this summer upwelling is spatially limited to a few hot spots, here we show that widespread phytoplankton blooms of moderate ( 1 mg/m3) chlorophyll a concentrations develop during autumn and early winter on most of Australia's extensive southern shelves—from the vast shelves of the Great Australian Bight (GAB) in the west to Bass Strait in the east. This surprising finding disproves the widespread belief that shelf waters of the GAB are generally oligotrophic and may explain the relatively high abundance of both forage fish (sardines) and upper trophic-level predators (e.g., tuna and whales) in the region.

  3. Deficiency of Bloom syndrome helicase activity is radiomimetic.

    Science.gov (United States)

    Horowitz, David P; Topaloglu, Ozlem; Zhang, Yonggang; Bunz, Fred

    2008-11-01

    Bloom syndrome is caused by homozygous mutations in BLM, which encodes a RecQ DNA helicase. Patient-derived cells deficient in BLM helicase activity exhibit genetic instability--apparent cytogenetically as sister chromatid exchanges--and activated DNA damage signaling. In this report, we show that BLM-knockout colorectal cancer cells exhibited endogenous, ATM-dependent double-strand DNA break responses similar to those recently observed in Bloom syndrome patient-derived cells. Xenograft tumors established from BLM-deficient cancer cells were not radiosensitive, but exhibited growth impairment that was comparable to that of wild type tumors treated with a single, high dose of ionizing radiation. These results suggest that pharmacological inhibitors of BLM would have a radiomimetic effect and that transient inhibition of BLM activity might be a viable strategy for anticancer therapy.

  4. The Revised Bloom's Taxonomy: implications for educating nurses.

    Science.gov (United States)

    Su, Whei Ming; Osisek, Paul J

    2011-07-01

    One of the essential goals for continuing education in nursing is to enhance nurses' ability to improve patient care outcomes. Toward this goal, learners need to transfer learned knowledge to actual practice. Achieving effective transfer requires knowledge of thinking paradigms in relation to specific subject content. Educators can facilitate knowledge transfer by developing instructional designs that incorporate subject content and cognitive processes related to the use of the subject content. However, it is difficult to develop such instructional designs. The Revised Bloom's Taxonomy provides a framework for meeting this educational need. In this article, the authors establish the relevance of the Revised Bloom's Taxonomy to continuing education and describe how to use the taxonomy to plan an educational session with an emphasis on promoting knowledge transfer.

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

    Directory of Open Access Journals (Sweden)

    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.

  6. 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.

  7. 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; 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. PMID:23874425

  8. 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.

  9. 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.

  10. Is global ocean sprawl a cause of jellyfish blooms?

    OpenAIRE

    Duarte, Carlos M.; Pitt, Kylie A.; Lucas, C.H.; Purcell, Jennifer E.; Uye, Shin-Ichi; Robinson, Kelly L.; Brotz, Lucas; Decker, MaryBeth; Kelly R Sutherland; Malej, Alenka; Madin, Laurence P.; Mianzan, Hermes; Gili, Josep-Maria; Fuentes, Veronica; Atienza, D.

    2013-01-01

    Jellyfish (Cnidaria, Scyphozoa) blooms appear to be increasing in both intensity and frequency in many coastal areas worldwide, due to multiple hypothesized anthropogenic stressors. Here, we propose that the proliferation of artificial structures – associated with (1) the exponential growth in shipping, aquaculture, and other coastal industries, and (2) coastal protection (collectively, “ocean sprawl”) – provides habitat for jellyfish polyps and may be an important driver of the global increa...

  11. 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.

  12. The Impact of Harmful Algal Blooms on USACE Operations

    Science.gov (United States)

    2009-01-01

    recorded history around the world (Paerl 2008). Freshwater algal blooms commonly consist of many cyanobacterial algal strains, also called “blue-green...competitive edge (Huisman et al. 2005). Microcystis, a hepatotoxin created by the Microcystis algae, is most frequently cited in reports of cyanobacteria ...related poisoning in humans and livestock (Chorus and Bartram 1999) and is the dominant cyanobacteria in North America (Carmichael 2005). It is important

  13. 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

  14. 多 MOSFET 并联均流的高稳定度恒流源研究%Research on the high stable constant current source based on multi-MOSFETs in paralleling connection

    Institute of Scientific and Technical Information of China (English)

    张存凯; 李正坤; 陈乐; 张钟华

    2016-01-01

    In this paper , an approach for a high stable constant current source is presented , which is based on multi-ple power MOSFETs paralleling connection method , the maxim output of current source is up to 30 A, and it is con-tinuously adjustable .The performance of the designed constant current source has been tested , and the measurement results indicate that the stability of constant source is better than 5 ppm when the current is 30 A.The working princi-ple of the designed constant current circuit is analyzed in detail , and the selection of key components is explained clearly.We use the high precision reference voltage source and current series negative feedback based on high -power precision sample resistor to increase the stability of system .In order to realize the high stable current , multiple MOS-FETs in paralleling connection are used as regulator , and systematic analysis on factors affecting MOSFETs in paralle-ling work are presented as well .The constant current source that we designed has a certain reference value for the de-sign of DC current source .%提出了一种基于多MOSFET并联均流的高稳定度大电流恒流源研究方案,输出电流最高可达30 A且连续可调,输出30 A时,30分钟内电流稳定度优于5 ppm。文中详细分析了恒流源基本稳流电路的工作原理,并对电路中关键元器件的选型进行了分析说明。通过高精度基准电压芯片和基于大功率精密电阻采样的电流串联负反馈方法提高系统的稳流精度,通过多只功率MOSFET并联均流工作作为调整管,实现了输出大电流的高稳定度,同时对影响功率MOSFET并联工作的因素进行了系统分析。提出的恒流源方案,对高稳定度直流电源的设计具有一定的参考价值。

  15. Toxin extraction from an Anabaenopsis milleri--dominated bloom.

    Science.gov (United States)

    Lanaras, T; Cook, C M

    1994-03-15

    This paper reports the presence of microcystin type toxins in extracts of a natural bloom of cyanobacteria composed predominantly of Anabaenopsis milleri Woronichin. The toxins have been extracted, purified and compared to microcystin-LR. The LD50 of A. milleri bloom material was 600-1500 mg lyophilized cells/kg body weight. Symptoms and pathological signs of poisoning in mice were characteristic of cyanobacterial hepatotoxins, with enlarged darkened livers with weights of 8-10% of the total body weight. Thin-layer chromatography of the extract resulted in one toxic band, which was separated from pigments and 280-nm absorbing compounds. The toxic fraction was further separated using reversed phase high performance liquid chromatography and one toxic band was recovered. This fraction yielded a single, toxic peak with a retention time of 11.3 min after high performance liquid chromatography. The absorption spectrum of the purified toxin had a maximum at 238-240 nm and was characteristic of cyanobacterial hepatotoxic peptides. Comparison of the chromatographic behaviour of the purified toxin with microcystin-LR on reversed phase and on internal surface reversed phase, high performance liquid chromatography indicated that an A. milleri bloom material toxin was a microcystin type toxin and it is highly likely that the purified toxin is microcystin-LR.

  16. Separation of wind's influence on harmful cyanobacterial blooms.

    Science.gov (United States)

    Wang, Hua; Zhang, Zhizhang; Liang, Dongfang; du, Hanbei; Pang, Yong; Hu, Kaimin; Wang, Jianjian

    2016-07-01

    Wind is an important physical factor involved in Harmful Cyanobacterial blooms (CyanoHABs). Its integrated influence was separated to three components: (a) Direct Disturbance Impact (DDI) on cyanbacterial proliferation, (b) Indirect Nutrient Impact (INI) by sediment release and (c) Direct Transportation Impact (DTI) by both gentle wind-induced surface drift and wave-generated Stokes drift. By the combination of field investigation, laboratory experiment and numerical simulation their individual contributions to the severe bloom event in May 2007 in Meiliang Bay, Lake Taihu, was explored. Wind synthetically made 10.5 percent promotion to the bloom on May 28, 2007, but the impact varied with locations. DTI was featured with the strongest contribution of wind's impacts on CyanoHABs, while INI stood at the lowest level and DDI played an intermediate role. From the point of whole Meiliang Bay, the influencing weights of DTI, DDI and INI were approximately 48.55%, 32.30% and 19.15% respectively. DTI exerted the higher promotion in the regions of middle-east (ME), southwest (SW) and southeast (SE), and its actual contribution rate on CyanoHABs ranged from 6.41% to 7.46%. Due to the background nutrient load, INI was characterized by a tiny effect with the contribution rate being 2.18% on average. From the south bay to the north, DDI was detected with a decreasing tendency, with the practical contribution rate generally falling from 4.13% to 2.7%.

  17. Volcanic ash fuels anomalous plankton bloom in subarctic northeast Pacific

    Science.gov (United States)

    Hamme, Roberta C.; Webley, Peter W.; Crawford, William R.; Whitney, Frank A.; DeGrandpre, Michael D.; Emerson, Steven R.; Eriksen, Charles C.; Giesbrecht, Karina E.; Gower, Jim F. R.; Kavanaugh, Maria T.; Peña, M. Angelica; Sabine, Christopher L.; Batten, Sonia D.; Coogan, Laurence A.; Grundle, Damian S.; Lockwood, Deirdre

    2010-10-01

    Using multiple lines of evidence, we demonstrate that volcanic ash deposition in August 2008 initiated one of the largest phytoplankton blooms observed in the subarctic North Pacific. Unusually widespread transport from a volcanic eruption in the Aleutian Islands, Alaska deposited ash over much of the subarctic NE Pacific, followed by large increases in satellite chlorophyll. Surface ocean pCO2, pH, and fluorescence reveal that the bloom started a few days after ashfall. Ship-based measurements showed increased dominance by diatoms. This evidence points toward fertilization of this normally iron-limited region by ash, a relatively new mechanism proposed for iron supply to the ocean. The observations do not support other possible mechanisms. Extrapolation of the pCO2 data to the area of the bloom suggests a modest ˜0.01 Pg carbon export from this event, implying that even large-scale iron fertilization at an optimum time of year is not very efficient at sequestering atmospheric CO2.

  18. 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.

  19. Current source grid connected inverter using fuzzy hysteresis technologies%电流型并网逆变器的模糊滞环控制

    Institute of Scientific and Technical Information of China (English)

    黄少辉; 林培杰; 程树英; 孙占东

    2015-01-01

    In order to improve the main shortcomings of hysteresis band control used in grid connected inverter where the switch frequency is not fixed, a new method that hysteresis comparator combined with fuzzy controler is proposed. By modeling the grid connected inverter and analyzing the principle of hysteresis current control , we have revealed that the switch frequency is closely related to the width of the hysteresis loop. We make grid voltage and the partial differential of instruction current as input variables to establish the fuzzy control rules. After some fuzzy arithmetic outputing hysteresis band. The switching frequency is stabilized by regulating the width of the hysteresis dynamically. The method has a high performance in reducing the current harmonics and decreasing the switching frequency. The simulation and experiment results demonstrate that this method is feasibility on stable hysteresis switching frequency, especially in zero crossing point and top point, meanwhile it can improve the harmonic characteristic.%为改善滞环控制应用在并网逆变器中会出现系统开关频率不固定的问题,提出一种将模糊控制器与滞环比较器相结合的控制方法。通过对并网逆变器的建模和滞环电流控制原理的分析,可知开关频率与滞环环宽之间的关系。以电网电压及指令电流的偏微分为输入变量建立模糊控制规则,经过一定的模糊运算输出滞环环宽,从而动态地控制环宽达到稳定频率的目的。该方法能有效地降低开关频率,减小电流谐波。仿真和实验结果证明了该方法对稳定滞环开关频率是有效的,尤其是在过零点与顶点处,同时能够改善谐波特性。

  20. An overview of historical harmful algae blooms outbreaks in the Arabian Seas.

    Science.gov (United States)

    Al Shehhi, Maryam R; Gherboudj, Imen; Ghedira, Hosni

    2014-09-15

    Harmful algae blooms (HABs), often composed of oceanic plants called phytoplankton, are potentially harmful to the marine life, water quality, human health, and desalination plants, a chief source of potable water in the Arabian Gulf. The last decade has seen a noticeable increase in the frequency of HAB outbreaks in the Arabian Seas. This increase is mainly caused by the unprecedented economic growth in the region. The increased human activities in the region have added more stress to the marine environment and contributed to the changes observed in the properties of the marine ecosystem: high temperature and salinity, high evaporation rates, limited freshwater inflow, shallow nature, pollution. However, very few studies that cover the HAB outbreaks, causes, impacts and biological characteristics over the region have been published. This work presents a comprehensive overview of historical HAB outbreaks recorded in the region, and investigate their causes and impact, and seasonal variability.

  1. A Multipath Routing Protocol Based on Bloom Filter for Multihop Wireless Networks

    Directory of Open Access Journals (Sweden)

    Junwei Jin

    2016-01-01

    Full Text Available On-demand multipath routing in a wireless ad hoc network is effective in achieving load balancing over the network and in improving the degree of resilience to mobility. In this paper, the salvage capable opportunistic node-disjoint multipath routing (SNMR protocol is proposed, which forms multiple routes for data transmission and supports packet salvaging with minimum overhead. The proposed mechanism constructs a primary path and a node-disjoint backup path together with alternative paths for the intermediate nodes in the primary path. It can be achieved by considering the reverse route back to the source stored in the route cache and the primary path information compressed by a Bloom filter. Our protocol presents higher capability in packet salvaging and lower overhead in forming multiple routes. Simulation results show that SNMR outperforms the compared protocols in terms of packet delivery ratio, normalized routing load, and throughput.

  2. The flower that didn't bloom

    DEFF Research Database (Denmark)

    Nielsen, Jens Kaalhauge

    2010-01-01

    This paper throws light on the question: why did the industrial revolution happen in the West and not in China? The key to an understanding of the development of China's civilization lies in the way China historically has been characterized by a peculiar 'freeze' of the cultural-political axis...... of societal differentiation. It's most direct manifestation was that of a monolith state. This had implications for the cognitive matrix of society, where a modern scientific system never developed, while at the same time China's rich sources of inventions were often poorly institutionalized. These flaws were...... in safeguarding Europe's trajectory. One essential prerequisite in this process is the lack of cultural and political hegemony characterizing Europe's history. By this token, the fall of the Roman Empire and the rise of a system of fragmented Germanic kingdoms in the initial years of the Middle Ages were...

  3. 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

    2010-09-10

    "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

  4. 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

  5. Web GIS in practice IV: publishing your health maps and connecting to remote WMS sources using the Open Source UMN MapServer and DM Solutions MapLab

    Directory of Open Access Journals (Sweden)

    Honda Kiyoshi

    2006-01-01

    Full Text Available Abstract Open Source Web GIS software systems have reached a stage of maturity, sophistication, robustness and stability, and usability and user friendliness rivalling that of commercial, proprietary GIS and Web GIS server products. The Open Source Web GIS community is also actively embracing OGC (Open Geospatial Consortium standards, including WMS (Web Map Service. WMS enables the creation of Web maps that have layers coming from multiple different remote servers/sources. In this article we present one easy to implement Web GIS server solution that is based on the Open Source University of Minnesota (UMN MapServer. By following the accompanying step-by-step tutorial instructions, interested readers running mainstream Microsoft® Windows machines and with no prior technical experience in Web GIS or Internet map servers will be able to publish their own health maps on the Web and add to those maps additional layers retrieved from remote WMS servers. The 'digital Asia' and 2004 Indian Ocean tsunami experiences in using free Open Source Web GIS software are also briefly described.

  6. Web GIS in practice IV: publishing your health maps and connecting to remote WMS sources using the Open Source UMN MapServer and DM Solutions MapLab.

    Science.gov (United States)

    Boulos, Maged N Kamel; Honda, Kiyoshi

    2006-01-18

    Open Source Web GIS software systems have reached a stage of maturity, sophistication, robustness and stability, and usability and user friendliness rivalling that of commercial, proprietary GIS and Web GIS server products. The Open Source Web GIS community is also actively embracing OGC (Open Geospatial Consortium) standards, including WMS (Web Map Service). WMS enables the creation of Web maps that have layers coming from multiple different remote servers/sources. In this article we present one easy to implement Web GIS server solution that is based on the Open Source University of Minnesota (UMN) MapServer. By following the accompanying step-by-step tutorial instructions, interested readers running mainstream Microsoft(R) Windows machines and with no prior technical experience in Web GIS or Internet map servers will be able to publish their own health maps on the Web and add to those maps additional layers retrieved from remote WMS servers. The 'digital Asia' and 2004 Indian Ocean tsunami experiences in using free Open Source Web GIS software are also briefly described.

  7. 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.

  8. Hardware-based high-performance string lookup with value retrieval using extended Bloom filter

    Institute of Scientific and Technical Information of China (English)

    LI Qi-yue; QU Yu-gui; ZHAO Bao-hua

    2008-01-01

    In network packet processing, high-performance string lookup systems are very important. In this article, an extended Bloom filter data structure is introduced to support value retrieval string lookup, and to improve its performance, a weighted extended Bloom filter (WEBF) structure is generalized. The optimal configuration of the WEBF is then derived, and it is shown that it outperforms the traditional Bloom filter. Finally, an application-specific integrated circuit (ASIC)-based technique using WEBF is outlined.

  9. Critical Examination of a Revision of Bloom's Taxonomy for the Development of Art Education Curriculum

    OpenAIRE

    中村, 和世; 大和, 浩子; 中島, 敦夫; 吉川, 和生

    2011-01-01

    This paper is aimed at developing Art Education Taxonomy Table through critically examining a revision of Bloom's Taxonomy of Educational Objectives contrived by Anderson and Krathwohl. First, the overview of the history of Bloom's Taxonomy is provided in relation to art education. Second, the influence of Bloom's theory of educational evaluation and Taxonomy on the classroom practice of art education in Japan is discussed. Third, aiming at using for the development of art education curriculu...

  10. Connectivity of a large embayment and coastal fishery: spawning aggregations in one bay source local and broad-scale fishery replenishment.

    Science.gov (United States)

    Hamer, P A; Acevedo, S; Jenkins, G P; Newman, A

    2011-04-01

    Ichthyoplankton sampling and otolith chemistry were used to determine the importance of transient spawning aggregations of snapper Chrysophrys auratus (Sparidae) in a large embayment, Port Phillip Bay (PPB), Australia, as a source of local and broad-scale fishery replenishment. Ichthyoplankton sampling across five spawning seasons within PPB, across the narrow entrance to the bay and in adjacent coastal waters, indicated that although spawning may occur in coastal waters, the spawning aggregations within the bay were the primary source of larval recruitment to the bay. Otolith chemical signatures previously characterized for 0+ year C. auratus of two cohorts (2000 and 2001) were used as the baseline signatures to quantify the contribution that fish derived from reproduction in PPB make to fishery replenishment. Sampling of these cohorts over a 5 year period at various widely dispersed fishery regions, combined with maximum likelihood analyses of the chemistry of the 0+ year otolith portions of these older fish, indicated that C. auratus of 1 to 3+ years of age displayed both local residency and broad-scale emigration from PPB to populate coastal waters and an adjacent bay (Western Port). While the PPB fishery was consistently dominated (>70%) by locally derived fish irrespective of cohort or age, the contribution of fish that had originated from PPB to distant populations increased with age. At 4 to 5+ years of age, when C. auratus mature and fully recruit to the fishery, populations of both cohorts across the entire central and western Victorian fishery, including two major embayments and c. 800 km of coastal waters, were dominated (>70%) by fish that had originated from the spawning aggregations and nursery habitat within PPB. Dependence of this broadly dispersed fishery on replenishment from heavily targeted spawning aggregations within one embayment has significant implications for management and monitoring programmes.

  11. 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.

  12. The 2008 Emiliania huxleyi bloom along the Patagonian Shelf: Ecology, biogeochemistry, and cellular calcification

    Science.gov (United States)

    Poulton, Alex J.; Painter, Stuart C.; Young, Jeremy R.; Bates, Nicholas R.; Bowler, Bruce; Drapeau, Dave; Lyczsckowski, Emily; Balch, William M.

    2013-12-01

    blooms are significant contributors to the global production and export of calcium carbonate (calcite). The Patagonian Shelf is a site of intense annual coccolithophore blooms during austral summer. During December 2008, we made intensive measurements of the ecology, biogeochemistry, and physiology of a coccolithophore bloom. High numbers of Emiliania huxleyi cells and detached coccoliths (>1 × 103 mL-1 and >10 × 103 mL-1, respectively), high particulate inorganic carbon concentrations (>10 mmol C m-2), and high calcite production (up to 7.3 mmol C m-2 d-1) all characterized bloom waters. The bloom was dominated by the low-calcite-containing B/C morphotype of Emiliania huxleyi, although a small (30%, similar to estimates for E. huxleyi and indicative of a significant role for this diatom in bloom biogeochemistry. Cell-normalized calcification rates, when corrected for a high number of nonactive cells, were relatively high and when normalized to estimates of coccolith calcite indicate excessive coccolith production in the declining phase of the bloom. We find that low measures of calcite and calcite production relative to other blooms in the global ocean indicate that the dominance of the B/C morphotype may lead to overall lower calcite production. Globally, this suggests that morphotype composition influences regional bloom inventories of carbonate production and export and that climate-induced changes in morphotype biogeography could affect the carbon cycle.

  13. 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

    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...... based carbon (PPC). The composition and quality of the sedimenting material changed throughout the bloom succession from PPC dominance in the initial phase with a POC/PON ratio close to 6.6 to a dominance of amorphous detritus with a higher POC/PON ratio (>10) in the post-bloom phase. The succession...

  14. The distribution and impacts of harmful algal bloom species in eastern boundary upwelling systems

    Science.gov (United States)

    Trainer, V. L.; Pitcher, G. C.; Reguera, B.; Smayda, T. J.

    2010-04-01

    Comparison of harmful algal bloom (HAB) species in eastern boundary upwelling systems, specifically species composition, bloom densities, toxin concentrations and impacts are likely to contribute to understanding these phenomena. We identify and describe HABs in the California, Canary, Benguela and Humboldt Current systems, including those that can cause the poisoning syndromes in humans called paralytic shellfish poisoning (PSP), diarrhetic shellfish poisoning (DSP), and amnesic shellfish poisoning (ASP), as well as yessotoxins, ichthyotoxins, and high-biomass blooms resulting in hypoxia and anoxia. Such comparisons will allow identification of parameters, some unique to upwelling systems and others not, that contribute to the development of these harmful blooms.

  15. Connecting dots

    DEFF Research Database (Denmark)

    Murakami, Kyoko; Jacobs, Rachel L.

    2017-01-01

    of connecting the dots of recalled moments of individual family members lives and is geared towards building a family’s shared future for posterity. Lastly, we consider a wider implication of family reminiscence in terms of human development. http://www.infoagepub.com/products/Memory-Practices-and-Learning...... and Middleton, 1995). A reminiscence conversation is a dynamic talk-in-interaction, which can produce valuable learning experience for the participants involved. Reminiscence talk contains rich, personal, historic data that can reveal and inform family members of an unknown past. In this seminar/chapter, we...... shall present a discursive approach, a methodology that captures the dynamics of reminiscence. We analyse collected conversational data of British family members reminiscing on their past as a joint family activity. Through such talk-in-interaction, the family members develop continuity within...

  16. Fe availability drives phytoplankton photosynthesis rates during spring bloom in the Amundsen Sea Polynya, Antarctica

    Directory of Open Access Journals (Sweden)

    Anne-Carlijn Alderkamp

    2015-04-01

    Full Text Available Abstract To evaluate what drives phytoplankton photosynthesis rates in the Amundsen Sea Polynya (ASP, Antarctica, during the spring bloom, we studied phytoplankton biomass, photosynthesis rates, and water column productivity during a bloom of Phaeocystis antarctica (Haptophyceae and tested effects of iron (Fe and light availability on these parameters in bioassay experiments in deck incubators. Phytoplankton biomass and productivity were highest (20 µg chlorophyll a L−1 and 6.5 g C m−2 d−1 in the central ASP where sea ice melt water and surface warming enhanced stratification, reducing mixed layer depth and increasing light availability. In contrast, maximum photosynthesis rate (P*max, initial light-limited slope of the photosynthesis–irradiance curve (α*, and maximum photochemical efficiency of photosystem II (Fv/Fm were highest in the southern ASP near the potential Fe sources of the Dotson and Getz ice shelves. In the central ASP, P*max, α*, and Fv/Fm were all lower. Fe addition increased phytoplankton growth rates in three of twelve incubations, and at a significant level when all experiments were analyzed together, indicating Fe availability may be rate-limiting for phytoplankton growth in several regions of the ASP early in the season during build-up of the spring bloom. Moreover, Fe addition increased P*max, α*, and Fv/Fm in almost all experiments when compared to unamended controls. Incubation under high light also increased P*max, but decreased Fv/Fm and α* when compared to low light incubation. These results indicate that the lower values for P*max, α*, and Fv/Fm in the central ASP, compared to regions close to the ice shelves, are constrained by lower Fe availability rather than light availability. Our study suggests that higher Fe availability (e.g., from higher melt rates of ice shelves would increase photosynthesis rates in the central ASP and potentially increase water column productivity 1.7-fold, making the ASP

  17. Island Partitioning and Optimal Connecting Point Search of Mobile Emergency Power Source Based on Graph Theory%基于图论的移动应急电源孤岛划分及最优接入点搜索

    Institute of Scientific and Technical Information of China (English)

    倪程捷; 房鑫炎; 赵文恺; 区伟健; 赵彤彤

    2015-01-01

    The mobile emergency power source(MEPS)takes up the power supply responsibility to important customers when blackout occurs in an urban distribution grid.The conversion of an island search problem into a precedence-constrained knapsack problem (PCKP) based on the graph model of distribution grid is proposed and solved by the exact recursion algorithm.Firstly,the optimization of the connecting point during operation is studied:obtaining every restored load value corresponding to every connecting point by forming an island at every node as the connecting point in the distribution grid.With this as the objective,the optimal connecting point of a single movable emergency source is found.Then multi-constraints optimization is made use of to solve the search for the connecting points of generation on the island.Finally,based on the optimal connecting point searching method of single MEPS,a process of generating multi-MEPS joint emergency power supply scheme is proposed.The results of a case study show that the method is able to make as much use of mobile power resources as possible to minimize economic loss.%在城市配电网发生大面积停电时,移动应急电源为重要用户提供孤岛应急电力资源。在配电网图模型的基础上,提出将孤岛划分问题转化为祖先约束背包问题,利用图论的精确递归法解决。首先深入研究了最优接入点的优化:通过在配电网每个节点形成孤岛,获得每个节点对应恢复负荷的失负荷价值总和。然后以此为目标,搜索到单台移动应急电源最优接入点,并利用多约束优化解决岛内电源接入点搜索问题。最后,在单台移动应急电源最优接入点搜索方法的基础上,给出了多台移动应急电源联合应急的方案制定方法,算例结果证明了该方法能最大程度地利用移动应急电力资源减小重要用户的经济损失。

  18. Controlling cyanobacterial blooms in hypertrophic Lake Taihu, China: will nitrogen reductions cause replacement of non-N2 fixing by N2 fixing taxa?

    Directory of Open Access Journals (Sweden)

    Hans W Paerl

    Full Text Available Excessive anthropogenic nitrogen (N and phosphorus (P inputs have caused an alarming increase in harmful cyanobacterial blooms, threatening sustainability of lakes and reservoirs worldwide. Hypertrophic Lake Taihu, China's third largest freshwater lake, typifies this predicament, with toxic blooms of the non-N2 fixing cyanobacteria Microcystis spp. dominating from spring through fall. Previous studies indicate N and P reductions are needed to reduce bloom magnitude and duration. However, N reductions may encourage replacement of non-N2 fixing with N2 fixing cyanobacteria. This potentially counterproductive scenario was evaluated using replicate, large (1000 L, in-lake mesocosms during summer bloom periods. N+P additions led to maximum phytoplankton production. Phosphorus enrichment, which promoted N limitation, resulted in increases in N2 fixing taxa (Anabaena spp., but it did not lead to significant replacement of non-N2 fixing with N2 fixing cyanobacteria, and N2 fixation rates remained ecologically insignificant. Furthermore, P enrichment failed to increase phytoplankton production relative to controls, indicating that N was the most limiting nutrient throughout this period. We propose that Microcystis spp. and other non-N2 fixing genera can maintain dominance in this shallow, highly turbid, nutrient-enriched lake by outcompeting N2 fixing taxa for existing sources of N and P stored and cycled in the lake. To bring Taihu and other hypertrophic systems below the bloom threshold, both N and P reductions will be needed until the legacy of high N and P loading and sediment nutrient storage in these systems is depleted. At that point, a more exclusive focus on P reductions may be feasible.

  19. Harmful algal blooms: a case study in two mesotrophic drinking water supply reservoirs in South Carolina

    Science.gov (United States)

    Journey, Celeste A.; Beaulieu, Karen M.; Knight, Rodney R.; Graham, Jennifer L.; Arrington, Jane M.; West, Rebecca; Westcott, John; Bradley, Paul M.

    2010-01-01

    Algal blooms can be harmful and a nuisance in a variety of aquatic ecosystems, including reservoirs and lakes. Cyanobacterial(blue-green algae) harmful algal blooms are notorious for producing both taste-and-odor compounds and potent toxins that may affect human health. Taste–and-odor episodes are aesthetic problems often caused by cyanobacterial-produced organic compounds (geosmin and methylisoborneol) and are common in reservoirs and lakes used as source water supplies. The occurrences of these taste-and-odor compounds and toxins (like microcystin) can be sporadic and vary in intensity both spatially and temporally. Recent publications by the U.S. Geological Survey address this complexity and provide protocols for cyanotoxin and taste-and-odor sampling programs. A case study conducted by the U.S. Geological Survey, in cooperation with Spartanburg Water, monitored two mesotrophic reservoirs that serve as public drinking water supplies in South Carolina. Study objectives were (1) to identify spatial and temporal occurrence of the taste-and-odor compound geosmin and the cyanotoxin microcystin and (2) to assess the associated limnological conditions before, during, and after these occurrences. Temporal and spatial occurrence of geosmin and microcystin were highly variable from 2007 to 2009. The highest geosmin concentrations tended to occur in the spring. Microcystin tended to occur in the late summer and early fall, but occurrence was rare and well below World Health Organization guidelines for finished drinking water and recreational activities. No current U.S. Environmental Protection Agency standards are applicable to cyanotoxins in drinking or ambient water. In general, elevated geosmin and microcystin concentrations were the result of complex interactions between cyanobacterial ⬚community composition, nutrient availability, water clarity, hydraulic residence time, and stratification.

  20. Unusual Bloom of Tetraselmis sp. in the Valparaiso Bay, Chile

    Science.gov (United States)

    2012-01-01

    base , in accordance with reference (a). , It is the opinion of the author that the subject paper (is __ ) (is not __ ,~><) classified, in...S data base , in ~c,cordelnce with reference (a). It Is the opinion of the author that the subject paper (Is __ ) (is not c/assiHed, in accordance...extinción de la luz, con el fin de describir las condiciones ambientales que se presentaron durante el bloom de enero de 2006. Los datos de radiación

  1. Phenolic Compounds Characterization and Biological Activities of Citrus aurantium Bloom

    Directory of Open Access Journals (Sweden)

    Armin Oskoueian

    2012-01-01

    Full Text Available Citrus plants are known to possess beneficial biological activities for human health. In addition, ethnopharmacological application of plants is a good tool to explore their bioactivities and active compounds. This research was carried out to evaluate the phenolic and flavonoid analysis, antioxidant properties, anti inflammatory and anti cancer activity of Citrus aurantium bloom. The total phenolics and flavonoids results revealed that methanolic extract contained high total phenolics and flavonoids compared to ethanolic and boiling water extracts. The obtained total phenolics value for methanolic Citrus aurantium bloom extract was 4.55 ± 0.05 mg gallic acid equivalent (GAE/g dry weight (DW, and for total flavonoids it was 3.83 ± 0.05 mg rutin equivalent/g DW. In addition, the RP-HPLC analyses of phenolics and flavonoids indicated the presence of gallic acid, pyrogallol, syringic acid, caffeic acid, rutin, quercetin and naringin as bioactive compounds. The antioxidant activity of Citrus aurantium bloom were examined by the 1,1-diphenyl-2-picryl-hydrazyl (DPPH assay and the ferric reducing/antioxidant potential (FRAP. The free radical scavenging and ferric reducing power activities were higher for the methanolic extract of Citrus aurantium bloom at a concentration of 300 μg/mL, with values of 55.3% and 51.7%, respectively, as compared to the corresponding boiling water and ethanolic extracts, but the activities were lower than those of antioxidant standards such as BHT and α-tocopherol. Furthermore, the anti-inflammatory result of methanolic extract showed appreciable reduction in nitric oxide production of stimulated RAW 264.7 cells at the presence of plant extract. Apart from that, the anticancer activity of the methanolic extract was investigated in vitro against human cancer cell lines (MCF-7; MDA-MB-231, human colon adenocarcinoma (HT-29 and Chang cell as a normal human hepatocyte. The obtained result demonstrated the moderate to

  2. The Bloom-Gilman duality and leading logarithms

    Energy Technology Data Exchange (ETDEWEB)

    Carlson, C.E. [College of William and Mary, Williamsburg, VA (United States); Mukhopadhyay, N.C. [Rensselaer Polytechnic Inst., Troy, NY (United States)

    1994-04-01

    The existing inclusive electroproduction data base allows the authors a look at the issue of the relative behaviors of background and resonance excitations, a part of the Bloom-Gilman duality. These data lack accuracy at high Q{sup 2} but establish PQCD scaling in the resonance region and even allow the authors a glimpse at the leading logarithmic corrections due to the gluon radiation and its possible quenching at large W and x. These should inspire better quality experimental tests at facilities like CEBAF II.

  3. Surveillance and treatment of malignancy in Bloom syndrome.

    Science.gov (United States)

    Thomas, E R A; Shanley, S; Walker, L; Eeles, R

    2008-06-01

    We report a patient with Bloom syndrome, a rare autosomal recessive condition characterised by chromosomal instability leading to a high risk of cancer at an early age. The diagnosis should be considered in patients with any cancer of significantly early onset, short stature and a photosensitive lupus-like rash on the face. Diagnostic confirmation is obtained from chromosome studies that show significantly increased numbers of sister chromatid exchanges. There are important management implications, including minimising the use of ionising radiation in surveillance and treatment.

  4. Control of toxic marine dinoflagellate blooms by serial parasitic killers.

    Science.gov (United States)

    Chambouvet, Aurelie; Morin, Pascal; Marie, Dominique; Guillou, Laure

    2008-11-21

    The marine dinoflagellates commonly responsible for toxic red tides are parasitized by other dinoflagellate species. Using culture-independent environmental ribosomal RNA sequences and fluorescence markers, we identified host-specific infections among several species. Each parasitoid produces 60 to 400 offspring, leading to extraordinarily rapid control of the host's population. During 3 consecutive years of observation in a natural estuary, all dinoflagellates observed were chronically infected, and a given host species was infected by a single genetically distinct parasite year after year. Our observations in natural ecosystems suggest that although bloom-forming dinoflagellates may escape control by grazing organisms, they eventually succumb to parasite attack.

  5. Evaluating a case study using Bloom's Taxonomy of Education.

    Science.gov (United States)

    Larkin, Brenda G; Burton, Karen J

    2008-09-01

    The joint commission recognizes effective communication among caregivers as an important factor for ensuring patient safety, especially at times when the patient's care is handed off from one caregiver or service to another. This case study reviews the course of treatment for one patient throughout the perioperative continuum, including the postoperative unit where a pre-arrest situation developed. A workshop using Bloom's Taxonomy of Educational Objectives enabled staff members to more clearly understand the patient's situation. It also allowed the participants to gain an increased understanding of significant data and has been strategic in preventing patient complications.

  6. Simulation of annual biogeochemical cycles of nutrient balance, phytoplankton bloom(s), and DO in Puget Sound using an unstructured grid model

    Energy Technology Data Exchange (ETDEWEB)

    Khangaonkar, Tarang; Sackmann, Brandon; Long, Wen; Mohamedali, Teizeen; Roberts, Mindy

    2012-08-14

    Nutrient pollution from rivers, nonpoint source runoff, and nearly 100 wastewater discharges is a potential threat to the ecological health of Puget Sound with evidence of hypoxia in some basins. However, the relative contributions of loads entering Puget Sound from natural and anthropogenic sources, and the effects of exchange flow from the Pacific Ocean are not well understood. Development of a quantitative model of Puget Sound is thus presented to help improve our understanding of the annual biogeochemical cycles in this system using the unstructured grid Finite-Volume Coastal Ocean Model framework and the Integrated Compartment Model (CE-QUAL-ICM) water quality kinetics. Results based on 2006 data show that phytoplankton growth and die-off, succession between two species of algae, nutrient dynamics, and dissolved oxygen in Puget Sound are strongly tied to seasonal variation of temperature, solar radiation, and the annual exchange and flushing induced by upwelled Pacific Ocean waters. Concentrations in the mixed outflow surface layer occupying approximately 5–20 m of the upper water column show strong effects of eutrophication from natural and anthropogenic sources, spring and summer algae blooms, accompanied by depleted nutrients but high dissolved oxygen levels. The bottom layer reflects dissolved oxygen and nutrient concentrations of upwelled Pacific Ocean water modulated by mixing with biologically active surface outflow in the Strait of Juan de Fuca prior to entering Puget Sound over the Admiralty Inlet. The effect of reflux mixing at the Admiralty Inlet sill resulting in lower nutrient and higher dissolved oxygen levels in bottom waters of Puget Sound than the incoming upwelled Pacific Ocean water is reproduced. Finally, by late winter, with the reduction in algal activity, water column constituents of interest, were renewed and the system appeared to reset with cooler temperature, higher nutrient, and higher dissolved oxygen waters from the Pacific

  7. Effects of nitrogen and phosphorus on the growth of Levanderina fissa: How it blooms in Pearl River Estuary

    Science.gov (United States)

    Wang, Zhaohui; Guo, Xin; Qu, Linjian; Lin, Langcong

    2017-02-01

    Effects of nitrogen (N) and phosphorus (P) from different sources and at different concentrations on the growth of Levanderina fissa (= Gyrodinium instriatum) were studied in laboratory conditions. The findings might explain the recurrent blooms of this species in Pearl River Estuary, China. Results showed that nutrient limitation significantly inhibited the growth of L. fissa. The values of specific growth rate ( μ max) and half-saturation nutrient concentration ( K S) were 0.37 divisions/d and 8.49 μmol L-1 for N, and 0.39 divisions/d and 1.99 μmol L-1 for P, respectively. Based on K S values, dissolved inorganic N level in PRE was sufficient to support the high proliferation of L. fissa, while dissolved inorganic P concentration was far lower than the minimum requirement for its effective growth. L. fissa was not able to utilize dissolved organic N (DON) compounds such as urea, amino acids, and uric acid. However, it grew well by using a wide variety of dissolved organic P (DOP) sources like nucleotides, glycerophosphate, and 4-nitrophenylphosphate. The results from this study suggested that the ability in DOP utilization of L. fissa offers this species a competitive advantage in phytoplankton communities. The high level and continuous supply of DIN, enrichment of DOP, together with warm climate and low salinity in the Pearl River Estuary provided a suitable nutrient niche for the growth of L. fissa, and resulted in the recurrent blooms in the estuary.

  8. LYSIS-INDUCED DECLINE OF A PHAEOCYSTIS SPRING BLOOM AND COUPLING WITH THE MICROBIAL FOODWEB

    NARCIS (Netherlands)

    VANBOEKEL, WHM; HANSEN, FC; RIEGMAN, R; BAK, RPM

    1992-01-01

    We studied the development and decline of the 1990 phytoplankton spring bloom in the Marsdiep area of the North Sea (The Netherlands) with emphasis on the cause of the decline of the Phaeocystis bloom, the role of microbial organisms and the utilization of organic material produced by the algae. At

  9. Random Access for Machine-Type Communication based on Bloom Filtering

    DEFF Research Database (Denmark)

    Pratas, Nuno; Stefanovic, Cedomir; Madueño, Germán Corrales;

    2016-01-01

    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...

  10. The phytoplankton spring bloom in Dutch coaqtal waters of the North Sea

    NARCIS (Netherlands)

    Gieskes, W.W.C.; Kraay, G.W.

    1975-01-01

    In the eastern part of the Southern Bight of the North Sea several sub areas could be distinguished, each with a characteristic spring bloom and species succession pattern. Regional differences in spring bloom timing were in accord with theoretical considerations in which (on the assumption of a ver

  11. Nuisance foam events and Phaeocystis globosa blooms in Dutch coastal waters analyzed with fuzzy logic

    NARCIS (Netherlands)

    Blauw, A.N.; Los, F.J.; Huisman, J.; Peperzak, L.

    2010-01-01

    Phaeocystis globosa is a nuisance algal species because it can cause foam on beaches which are associated with coastal blooms. Models of Phaeocystis have considered its bloom dynamics, but not the foam formation. The process of foam formation is poorly understood which limits the suitability of trad

  12. 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...

  13. 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…

  14. 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...

  15. 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,

  16. Impact of water level fluctuations on cyanobacterial blooms: Options for management

    NARCIS (Netherlands)

    Bakker, E.S.; Hilt, S.

    2016-01-01

    Climate change can promote harmful cyanobacteria blooms in eutrophic waters through increased droughts or flooding. In this paper, we explore how water-level fluctuations affect the occurrence of cyanobacterial blooms, and based on the observations from case studies, we discuss the options and pitfa

  17. Species dynamics in phytoplankton blooms: Incomplete mixing and competition for light

    NARCIS (Netherlands)

    Huisman, J.; Van Oostveen, P.; Weissing, F.J.

    1999-01-01

    With the eutrophication of many freshwaters and coastal environments, phytoplankton blooms have become a common phenomenon. This article uses a reaction-diffusion model to investigate the implications of mixing processes for the dynamics and species composition of phytoplankton blooms. The model ide

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

    NARCIS (Netherlands)

    Verspagen, J.M.H.; Van de Waal, D.B.; Finke, J.F; Visser, P.M.; Van Donk, E.; Huisman, J.

    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

  19. The decline process and major pathways of Microcystis bloom in Taihu Lake, China

    Institute of Scientific and Technical Information of China (English)

    WANG Zhicong; LI Guowen; LIGenbao; LI Dunhai

    2012-01-01

    Eutrophication has become a serious concern in many lakes,resulting in cyanobacterial blooms.However,the mechanism and pathways of cyanobacteria decline are less understood.To identify and define the growth and decline of Microcystis blooms in Taihu Lake of China,and to illuminate the destination of surface floating blooms,we investigated the biomass distribution and variations in colony size,morphology,and floating velocity from October 2008 to September 2009.The results showed that the Microcystis bloom declined in response to biomass decrease,colony disaggregation,buoyancy reduction,and increased phytoplankton biodiversity,and these indicative parameters could be applied for recognition of the development phases of the bloom.Three major decline pathways were proposed to describe the bloom decline process,colony disaggregation (Pathway Ⅰ),colony settlement (Pathway Ⅱ),and cell lysis in colonies (Pathway Ⅲ).We proposed a strategy to define the occurrence and decline of Microcystis blooms,to evaluate the survival state under different stress conditions,and to indicate the efficiency of controlling countermeasures against algal blooms.

  20. Species dynamics in phytoplankton blooms : Incomplete mixing and competition for light

    NARCIS (Netherlands)

    Huisman, J.; van Oostveen, P.; Weissing, F.J.

    1999-01-01

    With the eutrophication of many freshwaters and coastal environments, phytoplankton blooms have become a common phenomenon. This article uses a reaction-diffusion model to investigate the implications of mixing processes for the dynamics and species composition of phytoplankton blooms. The model ide

  1. Phytoplankton bloom and subpolar gyre induced dynamics in the North Atlantic

    DEFF Research Database (Denmark)

    Ferreira, Ana Sofia; Hátún, Hjálmar; Counillion, Francois;

    represents the integrated oceanic dynamics over the Northern North Atlantic, while the timing of the spring bloom is more governed by direct atmospheric forcing during the pre-bloom weeks. We, therefore, further investigate which published theories (Sverdrup [1953], Siegel et al [2002], Huisman et al [2002...

  2. Byatt versus Bloom; or Poetic Influence – a Case of Anxiety or Desire?

    DEFF Research Database (Denmark)

    Børch, Marianne

    2013-01-01

    Antonia Byatt's Possession; a Romance (1990) implicitly critiques Harold Bloom's theory of poetic influence as laid out in the influential Anxiety of Influence; her narrative suggests that a better metaphor than Bloom's Oedipal patricide would be that of love, an emotion that opens up for external...

  3. Lupus-like histopathology in bloom syndrome: reexamining the clinical and histologic implications of photosensitivity.

    Science.gov (United States)

    McGowan, Joseph; Maize, John; Cook, Joel

    2009-12-01

    Bloom syndrome is a rare genodermatosis of autosomal recessive inheritance. Although lupus-like skin lesions characterize this disorder, mechanisms of photosensitivity are poorly understood. In this case presentation, the authors report a patient with Bloom syndrome whose lupus-like facial rash revealed striking histopathologic similarities to cutaneous lupus erythematosus.

  4. 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…

  5. Critical Thinking in the Management Classroom: Bloom's Taxonomy as a Learning Tool.

    Science.gov (United States)

    Athanassiou, Nicholas; McNett, Jeanne M.; Harvey, Carol

    2003-01-01

    Using Bloom's taxonomy as a scaffolding device moves students toward self-management of learning. Analysis of journals and assignments completed by 42 students in business courses showed that repeated emphasis of Bloom's concepts improved higher-level conceptual thinking. (Contains 35 references.) (SK)

  6. Satellite-based detection and monitoring of phytoplankton blooms along the Oregon coast

    Science.gov (United States)

    McKibben, S. M.; Strutton, P. G.; Foley, D. G.; Peterson, T. D.; White, A. E.

    2012-12-01

    We have applied a normalized difference algorithm to 8 day composite chlorophyll-a (CHL) and fluorescence line height (FLH) imagery obtained from the Moderate Resolution Imaging Spectroradiometer aboard the Aqua spacecraft in order to detect and monitor phytoplankton blooms in the Oregon coastal region. The resulting bloom products, termed CHLrel and FLHrel, respectively, describe the onset and advection of algal blooms as a function of the percent relative change observed in standard 8 day CHL or FLH imagery over time. Bloom product performance was optimized to consider local time scales of biological variability (days) and cloud cover. Comparison of CHLrel and FLHrelretrievals to in situ mooring data collected off the central Oregon coast from summer 2009 through winter 2010 shows that the products are a robust means to detect bloom events during the summer upwelling season. Evaluation of winter performance was inconclusive due to persistent cloud cover and limited in situ chl-a records. Pairing the products with coincident in situ physical proxies provides a tool to elucidate the conditions that induce bloom onset and identify the physical mechanisms that affect bloom advection, persistence, and decay. These products offer an excellent foundation for remote bloom detection and monitoring in this region, and the methods developed herein are applicable to any region with sufficient CHL and FLH coverage.

  7. Use of remote sensing in monitoring and forecasting of harmful algal blooms

    Science.gov (United States)

    Stumpf, Richard P.; Tomlinson, Michelle C.

    2005-08-01

    Harmful algal blooms (HABs) have impacts on coastal economies, public health, and various endangered species. HABs are caused by a variety of organisms, most commonly dinoflagellates, diatoms, and cyanobacteria. In the late 1970's, optical remote sensing was found to have a potential for detecting the presence of blooms of Karenia brevis on the US Florida coast. Due to the nearly annual frequency of these blooms and the ability to note them with ocean color imagery, K. brevis blooms have strongly influenced the field of HAB remote sensing. However, with the variability between phytoplankton blooms, heir environment and their relatively narrow range of pigment types, particularly between toxic and non-toxic dinoflagellates and diatoms, techniques beyond optical detection are required for detecting and monitoring HABs. While satellite chlorophyll has some value, ecological or environmental characteristics are required to use chlorophyll. For example, identification of new blooms can be an effective means of identifying HABs that are quie intense, also blooms occurring after specific rainfall or wind events can be indicated as HABs. Several HAB species do not bloom in the traditional sense, in that they do not dominate the biomass. In these cases, remote sensing of SST or chlorophyll can be coupled with linkages to seasonal succession, changes in circulation or currents, and wind-induced transport--including upwelling and downwelling, to indicate the potential for a HAB to occur. An effective monitoring and forecasting system for HABs will require the coupling of remote sensing with an environmental and ecological understanding of the organism.

  8. Self-Awareness and Personal Growth: Theory and Application of Bloom's Taxonomy

    Science.gov (United States)

    Ugur, Hasan; Constantinescu, Petru-Madalin; Stevens, Michael J.

    2015-01-01

    Problem Statement: In this article, we summarize a group-based, self-development curriculum based on humanistic principles, framed by contemporary self-determination theory (SDT), and designed in accordance with Bloom's Taxonomy. The processes of awareness and integration are common to SDT and Bloom's Taxonomy, and to our knowledge, have not been…

  9. 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…

  10. An Evaluative Calculus Project: Applying Bloom's Taxonomy to the Calculus Classroom

    Science.gov (United States)

    Karaali, Gizem

    2011-01-01

    In education theory, Bloom's taxonomy is a well-known paradigm to describe domains of learning and levels of competency. In this article I propose a calculus capstone project that is meant to utilize the sixth and arguably the highest level in the cognitive domain, according to Bloom et al.: evaluation. Although one may assume that mathematics is…

  11. A Roof without Walls: Benjamin Bloom's Taxonomy and the Misdirection of American Education

    Science.gov (United States)

    Booker, Michael J.

    2007-01-01

    Plato wrote that higher order thinking could not start until the student had mastered conventional wisdom. The American educational establishment has turned Plato on his head with the help of a dubious approach to teaching developed by one Benjamin Bloom. Bloom's taxonomy was intended for higher education, but its misappropriation has resulted in…

  12. Evaluating Course-Objective Writing Effectiveness: Applying the Comprehensive Bloom Verb List

    Science.gov (United States)

    Baker, Russell; Almerico, Gina M.; Thornton, Barry

    2008-01-01

    This study is a comparative analysis of the objective writing skills of pre-service teachers to determine the efficacy of utilizing a master verb list based on Bloom's Taxonomy. Students enrolled in a mid-size university were asked to create a set of objectives to measure Bloom's Taxonomy learning outcomes. One group received a master list of…

  13. An epizootic of Florida manatees associated with a dinoflagellate bloom

    Science.gov (United States)

    O'Shea, T.J.; Rathbun, G.B.; Bonde, R.K.; Buergelt, C.D.; Odell, D.K.

    1991-01-01

    Over a 10-wk period in early 1982, 39 Florida manatees (Trichechus manatus latirostris) were found dead in the lower Caloosahatchee River and nearby waters of southwestern Florida. Two were killed by boats. The remainder showed no evidence of trauma. Lesions indicative of infectious agents were not identified, and bacteriological and contaminant residue findings were unremarkable. Nonspecific lesions of congestion and hemorrhage were identified in brain tissue. Numerous reports were also received of manatee morbidity. Some distressed manatees showed no biochemical lesions in clinical analyses of blood samples and recovered quickly. Timing of manatee illnesses coincided with fish and double-crested cormorant (Phalacrocorax auritus) mortality and morbidity. A widespread bloom of the dinoflagellate red tide organism (Gymnodinium breve) also coincided with these incidents. G. breve produces potent neurotoxins (brevetoxins). Circumstantial evidence links these events, and possible routes of exposure may include ingestion of filter-feeding ascidians. Ecological conditions that magnified the extent of the epizootic included an early dispersal of manatees into the area from a nearby winter aggregation site and unusually high salinities that facilitated the inshore spread of the red tide bloom. Management responses to future episodes of red tide in manatee areas are suggested.

  14. 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.

  15. 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.

  16. Effects of nutrients on Microcystis growth more easily forming bloom

    Institute of Scientific and Technical Information of China (English)

    OU Ming-ming; ZHOU Bao-xue; XIE Wei-jie; JIANG Ju-hui; CAI Wei-min

    2004-01-01

    Different nutrient media experimentally were N, P and Fe-limited conditions and a serial of diluted BG11 media. The cell change of morphology and life history, cell number, cell color and cell area of Microcystis were analyzed quantitatively. First, the effects of nitrogen, phosphorus and iron depletion were distinctively different. Phosphorus and iron depletion caused more special division cells, slowly growth increasing, the easier change of bigger cell area. Second, the nitrogen and iron depletion could make the color of alga from green to brown. Finally, according to the resource competition and Monod equation, Microcystis kinetics of phosphorus and iron were also examined. Ks and μmax of phosphorus absorption were 0.0352 μmol/L, 0.493 d-1 respectively; iron absorption: 0.00323 μmol/L, 0.483 d-1. In a word, some evidences of the Microcystis bloom privilege in certain nutrient conditions were indicated in the experiments. The privileges were determined as the reviving under the adverse circumstances through the special division, the various nitrogen resources, and the lower kinetics of phosphorus and iron than that of most of other algae. The conclusions provided the scientific basis for preventing and managing Microcystis bloom in freshwater.

  17. Lake level fluctuations boost toxic cyanobacterial "oligotrophic blooms".

    Directory of Open Access Journals (Sweden)

    Cristiana Callieri

    Full Text Available Global warming has been shown to strongly influence inland water systems, producing noticeable increases in water temperatures. Rising temperatures, especially when combined with widespread nutrient pollution, directly favour the growth of toxic cyanobacteria. Climate changes have also altered natural water level fluctuations increasing the probability of extreme events as dry periods followed by heavy rains. The massive appearance of Dolichospermum lemmermannii ( = planktonic Anabaena, a toxic species absent from the pelagic zone of the subalpine oligotrophic Lake Maggiore before 2005, could be a consequence of the unusual fluctuations of lake level in recent years. We hypothesized that these fluctuations may favour the cyanobacterium as result of nutrient pulses from the biofilms formed in the littoral zone when the lake level is high. To help verify this, we exposed artificial substrates in the lake, and evaluated their nutrient enrichment and release after desiccation, together with measurements of fluctuations in lake level, precipitation and D. lemmermannii population. The highest percentage of P release and the lowest C:P molar ratio of released nutrients coincided with the summer appearance of the D. lemmermannii bloom. The P pulse indicates that fluctuations in level counteract nutrient limitation in this lake and it is suggested that this may apply more widely to other oligotrophic lakes. In view of the predicted increase in water level fluctuations due to climate change, it is important to try to minimize such fluctuations in order to mitigate the occurrence of cyanobacterial blooms.

  18. 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.

  19. Critical interaction domains between bloom syndrome protein and RAD51.

    Science.gov (United States)

    Bergeron, Krystal L; Murphy, Eileen L; Brown, Lily W; Almeida, Karen H

    2011-01-01

    The American Cancer Society's 2009 statistics estimate that 1 out of every 4 deaths is cancer related. Genomic instability is a common feature of cancerous states, and an increase in genomic instability is the diagnostic feature of Bloom Syndrome. Bloom Syndrome, a rare disorder characterized by a predisposition to cancer, is caused by mutations of the BLM gene. This study focuses on the partnerships of BLM protein to RAD51, a Homologous Recombination repair protein essential for survival. A systematic set of BLM deletion fragments were generated to refine the protein binding domains of BLM to RAD51 and determine interacting regions of BLM and ssDNA. Results show that RAD51 and ssDNA interact in overlapping regions; BLM₁₀₀₋₂₁₄ and BLM₁₃₁₇₋₁₃₆₇. The overlapping nature of these regions suggests a preferential binding for one partner that could function to regulate homologous recombination and therefore helps to clarify the role of BLM in maintaining genomic stability.

  20. Revisiting Bloom's taxonomy for ethics and other educational domains.

    Science.gov (United States)

    Porter, Russell D; Schick, Ida Critelli

    2003-01-01

    In the process of developing competency-based health services administration education, the Ethics Faculty Forum Co-Chairs from the Association of University Programs in Health Administration (AUPHA) were asked not only to identify their domains and competencies, but also to review six other faculty fora research outcomes. This article was written by the Ethics Faculty Forum Co-Chairs in response to the AUPHA request. Reviewing the work of the original six faculty fora using Bloom's taxonomy, we found that the fora focused mainly on the cognitive objectives and generally did not consider the affective objectives. The intent of this paper is to help those who teach healthcare ethics refine their current courses to include both cognitive and affective objectives. The paper pursues five objectives: 1. review of Bloom's taxonomy as a framework for creating course objectives in both the cognitive and affective domains; 2. present fora research and their domain outcomes; 3. present an overview of healthcare ethics literature; 4. provide a demonstration of healthcare ethics competencies in both the cognitive and affective domains; and 5. present possible directions for healthcare ethics and other educational domain research.

  1. A classification of the ISIS program using Bloom's cognitive taxonomy

    Science.gov (United States)

    Clevenstine, Richard F.

    This article focuses on the practical use of Bloom's Taxonomy of Educational Objectives. The current status of analyzing and classifying test items and behavioral objectives was examined in this study. Specifically, the purpose of this study was to analyze and classify the ISIS minicourse performance objectives and criterion-referenced test items according to Bloom's cognitive Taxonomy in order to determine what levels of cognition the ISIS instructional materials are directed. The performance objectives and test items of thirty-three ISIS minicourses and criterion-referenced tests were collected and classified. Four research questions were posed in the study. The findings indicate that ISIS minicourse test items and performance objectives are written primarily at the Knowledge and Comprehension levels. The ISIS instructional materials reflect low percentages of upper cognitive level test items and performance objectives. Based upon the use of a chi-square analysis, twenty-four of the ISIS minicourses and tests demonstrate a positive congruence between their performance objectives and criterion-referenced test items. Nine ISIS minicourses were found to demonstrate a negative relationship between their performance objectives and test items. Implications and Recommendations based on the findings of the studies are provided.

  2. Research on the Z-Source Inverter Grid-Connected Control of Micro-Grid System Based on Differential Geometry%基于微分几何的微网Z源逆变器并网控制

    Institute of Scientific and Technical Information of China (English)

    陈艳; 周林; 雷建; 甘元兴

    2012-01-01

    针对应用于微网系统中的Z源逆变器及其并网控制研究,以光伏系统为例,根据Z源变换器本身具有的非线性特性,建立Z源逆变器直流链及逆变侧的仿射非线性模型,利用微分几何基本工具,构造恰当的坐标变换和预反馈,将原非线性系统精确线性化,然后对该系统进行线性最优控制器设计。该逆变器集最大功率点跟踪、升降压和并网发电等功能于一体。仿真及实验表明:当光伏电池在输入条件发生变化时,本文控制方法能够使Z源逆变器直流链快速稳定无超调地跟踪最大功率点,逆变侧输出的三相电压能够实现快速平稳过渡并改善并网电流畸变。%For the Z-source inverter used in the distributed generation system and its grid-connected control,the paper takes the photovoltaic system as the example.According to the nonlinear characteristic of Z-source inverter,the affine model of Z-source inverter DC-link and AC side are created.Based on the differential geometry,the proper coordinate transformation and pre-feedback are constructed,and the original nonlinear system is exact linearized,then designed linear optimal controller for the system.The inverter integrates three functions including maximum power point tracking(MPPT),step-up/down DC-side voltage and output grid-connected.The simulation and experiment are performed to validate the strategies: when input condition of the photovoltaic array changes,this method has better performance than PI control.

  3. Free polyamine content during algal bloom succession in the East China Sea in spring 2010

    Science.gov (United States)

    Liu, Yan; Zhao, Weihong; Li, Caiyan; Miao, Hui

    2017-01-01

    We measured the concentrations and distribution of major polyamines (spermine, putrescine and spermidine) in seawater during successive spring algal blooms in an area of frequent harmful blooms in the East China Sea. Spermine, putrescine, and spermidine concentrations were analyzed by high performance liquid chromatography and ranged from 1-64, 7-81, and 0-19 nmol/L. Spermine was present at the highest concentrations, followed by putrescine and spermidine. In late April, when a diatom bloom dominated by Skeletonema costatum dispersed, polyamine concentrations increased, presumably as a result of diatom decomposition. In early May, when a dinoflagellate bloom dominated by Prorocentrum donghaiense occurred, the polyamine concentration decreased from the level seen in late April. The abundant polyamines that decomposed and were released during the diatom bloom in late April may have promoted the growth of P. donghaiense, resulting in its dominance.

  4. Accumulated chilling hours during endodormancy impact blooming and fruit shape developmentin peach (Prunus persicaL.)

    Institute of Scientific and Technical Information of China (English)

    LI Yong; FANG Wei-chao; ZHU Geng-rui; CAO Ke; CHEN Chang-wen; WANG Xin-wei; WANG Li-rong

    2016-01-01

    Winter chil is essential for the growth and development of deciduous species. To understand the relationship between accumulated chiling hours during endodormancy and blooming and fruit shape development, we controled chiling hours and investigated their effects on blooming date and fruit shape of peaches. The results showed that the number of days to full bloom date and the heat requirement for blooming were negatively correlated with accumulated chilling hours. Accumulated chiling hours were signiifcantly negatively correlated with fruit shape index and fruit tip lengths, suggesting that the number of chiling hours affect the fruit shape development. Fewer accumulated chiling hours may be the major reason for longer fruit shape and protruding fruit tips. In conclusion, our results indicate speciifcaly that decreased winter chiling hours can delay the bloom date and may lead to aberrant fruit shape development in peaches. Our study provides preliminary insights into the response of temperate fruit species to global climate change.

  5. 基于Bloom Filter的网络爬虫URL消重算法研究

    Institute of Scientific and Technical Information of China (English)

    王春梅

    2011-01-01

    针对网络大量重复页面,本文研究基于Bloom Filter的网络爬虫URL地址消重算法.首先,本文对Bloom Filter算法进行了分析研究;其次,本文应用Bloom Filter算法设计并实现了网络爬虫的URL消重;最后,论文采用URL消重率争爬虫爬取某类网站所用时间等性能指标,对基于遍历法和基于MD5算法的URL消重性能与基于Bloom Filter的消重性能做了对比.实验证明,基于Bloom Filter的网络爬虫URL地址消重算法效率较高.

  6. Is Occurrence of Harmful Algal Blooms in the Exclusive Economic Zone of India on the Rise?

    Directory of Open Access Journals (Sweden)

    K. B. Padmakumar

    2012-01-01

    Full Text Available Occurrence, increase in frequency, intensity and spatial coverage of harmful algal blooms during the past decade in the EEZ of India are documented here. Eighty algal blooms were recorded during the period 1998–2010. Of the eighty algal blooms, 31 blooms were formed by dinoflagellates, 27 by cyanobacteria, and 18 by diatoms. Three raphidophyte and one haptophyte blooms were also observed. Potentially toxic microalgae recorded from the Indian waters were Alexandrium spp., Gymnodinium spp. Dinophysis spp., Coolia monotis, Prorocentrum lima, and Pseudo-nitzschia spp. Examination of available data from the literature during the last hundred years and in situ observations during 1998–2010 indicates clear-cut increase in the occurrence of HABs in the Indian EEZ.

  7. Transcultural Tectonic Connections

    DEFF Research Database (Denmark)

    Carter, Adrian

    2014-01-01

    This paper presents an understanding of Jørn Utzon, as one of the most profound exponents of a transcultural and tectonic approach to modern architecture in the late twentieth century. The paper will examine the sources of inspiration, intersections and connections in Utzon’s architecture; which...... ruins in Mexico. The Sydney Opera House’s signature sail-like roof shells derive from knowledge of boat building in his youth and ancient Chinese and Japanese temple roofs floating above a stone base. With the choice of ceramic tiles to accentuate the sculptural character of the shells, owing its...

  8. Naturally Connecting the World

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    @@ During China International Trade Fair for Home Textiles and Accessories held in Shanghai 2010(on Aug.25th the second day of the fair),Cotton Council International(CCI)hosted an exchange meeting targeted the COTTON USATM home textile licenses,taking"Naturally Connecting the World-Opportunities for Sourcing and Collaboration with Cotton-Made Home Textiles"as the theme of the meeting.CCI's representative institution in China invited the domestic famous home textile brands,enterprises and their customers to participate in the exchange which aims to introduce the current development trend of the global cotton textile industry through CCI,the powerful platform of communication.

  9. 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.

  10. Connectivity of communication networks

    CERN Document Server

    Mao, Guoqiang

    2017-01-01

    This book introduces a number of recent developments on connectivity of communication networks, ranging from connectivity of large static networks and connectivity of highly dynamic networks to connectivity of small to medium sized networks. This book also introduces some applications of connectivity studies in network optimization, in network localization, and in estimating distances between nodes. The book starts with an overview of the fundamental concepts, models, tools, and methodologies used for connectivity studies. The rest of the chapters are divided into four parts: connectivity of large static networks, connectivity of highly dynamic networks, connectivity of small to medium sized networks, and applications of connectivity studies.

  11. Theoretical analysis for scaling law of thermal blooming based on optical phase deference

    Science.gov (United States)

    Sun, Yunqiang; Huang, Zhilong; Ren, Zebin; Chen, Zhiqiang; Guo, Longde; Xi, Fengjie

    2016-10-01

    In order to explore the laser propagation influence of thermal blooming effect of pipe flow and to analysis the influencing factors, scaling law theoretical analysis of the thermal blooming effects in pipe flow are carry out in detail based on the optical path difference caused by thermal blooming effects in pipe flow. Firstly, by solving the energy coupling equation of laser beam propagation, the temperature of the flow is obtained, and then the optical path difference caused by the thermal blooming is deduced. Through the analysis of the influence of pipe size, flow field and laser parameters on the optical path difference, energy scaling parameters Ne=nTαLPR2/(ρɛCpπR02) and geometric scaling parameters Nc=νR2/(ɛL) of thermal blooming for the pipe flow are derived. Secondly, for the direct solution method, the energy coupled equations have analytic solutions only for the straight tube with Gauss beam. Considering the limitation of directly solving the coupled equations, the dimensionless analysis method is adopted, the analysis is also based on the change of optical path difference, same scaling parameters for the pipe flow thermal blooming are derived, which makes energy scaling parameters Ne and geometric scaling parameters Nc have good universality. The research results indicate that when the laser power and the laser beam diameter are changed, thermal blooming effects of the pipeline axial flow caused by optical path difference will not change, as long as you keep energy scaling parameters constant. When diameter or length of the pipe changes, just keep the geometric scaling parameters constant, the pipeline axial flow gas thermal blooming effects caused by optical path difference distribution will not change. That is to say, when the pipe size and laser parameters change, if keeping two scaling parameters with constant, the pipeline axial flow thermal blooming effects caused by the optical path difference will not change. Therefore, the energy scaling

  12. Laser-induced breakdown spectroscopy of scaled steel samples taken from continuous casting blooms

    Science.gov (United States)

    Meinhardt, Christoph; Sturm, Volker; Fleige, Rüdiger; Fricke-Begemann, Cord; Noll, Reinhard

    2016-09-01

    To analyse continuous casting steel blooms a removal of non-representative surface layers is required prior to the analysis. In this work, an optimized process is developed to ablate such layers and to analyse the bulk material underneath with laser-induced breakdown spectroscopy (LIBS). A high ablation rate is crucial since the time slot for an inline analysis is limited, e.g. to metallic layers and typically have thicknesses from 200 μm to 600 μm each. The ablation behaviour of the oxide differs significantly from that of the metallic layers. An operation scheme for inline material identification is worked out to perform ablation and analysis with a single laser source. During the ablation phase and the subsequent measurement phase the laser source is operated with individually tailored parameters. A total penetration depth exceeding 1 mm in steel can be achieved within 20 s of ablation. Thereby the influence of non-representative surface layers on the following LIBS measurement can be suppressed to a large extent. For chromium, relative root mean square errors of predictions of less than 13% were achieved on high alloy samples with up to 16 m.-% Cr and on low alloy samples with Cr contents below 2 m.-%.

  13. Interactions between algal-bacterial populations and trace metals in fjord surface waters during a nutrient stimulated summer bloom

    DEFF Research Database (Denmark)

    Muller, F.; Larsen, A.; Stedmon, C.;

    2005-01-01

    this period, the weaker Cu-binding ligands appeared to have the same source or production process as the proteinlike fluorophores detected in these coastal waters. Zinc speciation was controlled by complexation with a single class of organic ligands that appeared to be released inadvertently upon the death......We examined how variations in algal-bacterial community structure relate to Cu, Zn, and Mn speciation during a diatom-rich bloom that was induced by daily additions of inorganic macronutrients to fjord waters in August 2002. The experiments were carried out in 11-m3 floating mesocosm bags deployed...... and/or grazing of phytoplankton. Labile manganese fluctuations were inversely synchronized with the abundance of heterotrophic bacteria until the coastal waters experienced a massive rain event on day 17 of the experiment. The rainfall, which was a source of nitrogen and micronutrients, appeared...

  14. Environmental and biological factors controlling the spring phytoplankton bloom at the Patagonian shelf-break front - Degraded fucoxanthin pigments and the importance of microzooplankton grazing

    Science.gov (United States)

    Carreto, José I.; Montoya, Nora G.; Carignan, Mario O.; Akselman, Rut; Acha, E. Marcelo; Derisio, Carla

    2016-08-01

    SBF showed a later stage of the bloom development, but the large population of diatoms under Si limitation was not in senescence and losses from microzooplankton grazing were minor. The observed high proportion of Chl a below a shallow upper mixed layer (up to 85%) could directly reach the bed, favoring the development of epibenthic communities and the formation of seed diatom banks and organic iron-rich sediments. The upwelling along the SBF provides a large source of macronutrients and probably the dissolved iron needed to sustain the intense diatom bloom, but also diatom resting stages that could act as seeds for the next spring bloom. The macronutrient-rich MC region showed low chlorophyll (Chl a < 0.8 mg m-3) and a highly diverse phytoplankton community, mainly composed of small cells (diatoms 20-70%, haptophytes 20-40%, chlorophytes 2-25%, prasinophytes 2-18%, and cryptophytes 3-12% of total Chl a).

  15. Discussion about mechanism of harmful algal blooms breakout

    Institute of Scientific and Technical Information of China (English)

    BU Xianwei; XU Weiyi; ZHU Dedi; CHEN Gengxin

    2005-01-01

    HAB (harmful algal bloom) is a serious marine ecological disaster. Up to now there is no definite conclusion about its mechanism of occurrence.The observation results show that the HAB breakout in the Xiangshan Bay was mainly caused by physical convergence ca pacity,and the breakout process had no direct relation to eutrophication. As a new idea it is thought that the process of the HAB break out is mainly a physical convergence or accumulation process in some areas. A hypothesis about dynamic mechanism of the HAB ap pearing in the area off the Changjiang Estuary is put forward according to hydrology and topography and the past work, and a breakthrough is expected to be made for doing further research.

  16. Bloom syndrome and maternal uniparental disomy for chromosome 15

    Energy Technology Data Exchange (ETDEWEB)

    Woodage, T.; Prasad, M.; Trent, R.J.; Smith, A. (Children' s Hospital, Camperdown, New South Wales (New Zealand)); Dixon, J.W.; Romain, D.R.; Columbano-Green, L.M.; Selby, R.E. (Wellington Hospital (New Zealand)); Graham, D. (Waikato Hospital, Hamilton (New Zealand)); Rogan, P.K. (Pennsylvania State Univ., Hershey, PA (United States)) (and others)

    1994-07-01

    Bloom syndrome (BS) is an autosomal recessive disorder characterized by increases in the frequency of sister-chromatid exchange and in the incidence of malignancy. Chromosome-transfer studies have shown the BS locus to map to chromosome 15q. This report describes a subject with features of both BS and Prader-Willi syndrome (PWS). Molecular analysis showed maternal uniparental disomy for chromosome 15. Meiotic recombination between the two disomic chromosomes 15 has resulted in heterodisomy for proximal 15q and isodisomy for distal 15q. In this individual BS is probably due to homozygosity for a gene that is telomeric to D15S95 (15q25), rather than to genetic imprinting, the mechanism responsible for the development of PWS. This report represents the first application of disomy analysis to the regional localization of a disease gene. This strategy promises to be useful in the genetic mapping of other uncommon autosomal recessive conditions. 37 refs., 3 figs., 2 tabs.

  17. Three new BLM gene mutations associated with Bloom syndrome.

    Science.gov (United States)

    Amor-Guéret, Mounira; Dubois-d'Enghien, Catherine; Laugé, Anthony; Onclercq-Delic, Rosine; Barakat, Abdelhamid; Chadli, Elbekkay; Bousfiha, Ahmed Aziz; Benjelloun, Meriem; Flori, Elisabeth; Doray, Bérénice; Laugel, Vincent; Lourenço, Maria Teresa; Gonçalves, Rui; Sousa, Silvia; Couturier, Jérôme; Stoppa-Lyonnet, Dominique

    2008-06-01

    Bloom's syndrome (BS) is a rare autosomal recessive disease predisposing patients to all types of cancers affecting the general population. BS cells display a high level of genetic instability, including a 10-fold increase in the rate of sister chromatid exchanges, currently the only objective criterion for BS diagnosis. We have developed a method for screening the BLM gene for mutations based on direct genomic DNA sequencing. A questionnaire based on clinical information, cytogenetic features, and family history was addressed to physicians prescribing BS genetic screening, with the aim of confirming or guiding diagnosis. We report here four BLM gene mutations, three of which have not been described before. Three of the mutations are frameshift mutations, and the fourth is a nonsense mutation. All these mutations introduce a stop codon, and may therefore be considered to have deleterious biological effect. This approach should make it possible to identify new mutations and to correlate them with clinical information.

  18. Sea-ice retreat controls timing of summer plankton blooms in the Eastern Arctic Ocean

    Science.gov (United States)

    Janout, Markus A.; Hölemann, Jens; Waite, Anya M.; Krumpen, Thomas; Appen, Wilken-Jon; Martynov, Fedor

    2016-12-01

    Two full-year mooring records of sea-ice, physical, and bio-optical parameters illuminate tight temporal coupling between the retreating seasonal ice edge and the summer phytoplankton bloom on the Laptev Sea shelf. Our records showed no sign of pelagic under-ice blooms despite available nutrients and thinning sea ice in early summer, presumably because stratification had not yet developed. Chlorophyll blooms were detected immediately after the ice retreated in late May 2014 and late July 2015. Despite radically different timing, the blooms were similar in both magnitude and length, interpreted as community-level nutrient limitation. Acoustic backscatter records suggest the delayed 2015 bloom resulted in lower zooplankton abundance, perhaps due to a timing mismatch between ice algal and pelagic blooms and unfavorable thermal conditions. Our observations provide classical examples of ice-edge blooms and further emphasize the complexity of high-latitude shelves and the need to understand vertical mixing processes important for stratification and nutrient fluxes.

  19. 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 Geosmin (87%), 2-methylisoborneol (39%), anatoxin-a (30%), saxitoxins (17%), cylindrospermopsins (9%), and nodularin-R (9%) also were present in these blooms. Multiple classes of 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.

  20. The bloom of nitrogen-fixing cyanobacteria in the northern Baltic Proper stimulates summer production

    Science.gov (United States)

    Svedén, Jennie B.; Walve, Jakob; Larsson, Ulf; Elmgren, Ragnar

    2016-11-01

    In the northern Baltic Sea Proper, total nitrogen (TN) increases during the summer bloom of filamentous heterocystous cyanobacteria. To follow the fate of the nitrogen they fix, we studied several N fractions during the bloom. We measured cyanobacterial biomass, TN, particulate organic N (PON, two size fractions), dissolved organic N (DON), and PON sedimentation in two areas in 2011. TN increased mainly due to increasing PON, but also to DON. Cyanobacteria contributed about 20% of the PON increase and ~ 10% of the TN increase. About half the PON changes (increase, then decrease) could be explained by the sum of cyanobacteria, other autotrophs (> 2 μm) and zooplankton, indicating that the bloom stimulates primary and secondary production. TN decreased after the bloom mainly due to declining PON > 10 μm, but sedimentation rates did not increase and could explain little of the post-bloom N-loss. There was little settling of undecomposed cyanobacteria. The seasonal development of Aphanizomenon sp. and N pools was similar among stations and areas. For Nodularia spumigena between-station variability increased once patchy surface accumulations developed. A brief Dolichospermum spp. bloom indicated that sampling frequency may be more important than spatial resolution for capturing dynamics of this bloom.

  1. Factors determining the diurnal dynamics of blooming of chosen plant species

    Directory of Open Access Journals (Sweden)

    Bożena Denisow

    2012-12-01

    Full Text Available The paper attempts to synthesize the determinants which may influence the diurnal rhythm of blooming. Additionally, I tried to explore and bring together topics that concern blooming and have always been considered separately because of their origin in different disciplines. The following species were included: Hydrangea arborescens L. subsp. discolor (Raf., H. paniculata Sieb., Viburnum opulus L., Chaenomeles japonica Lindl., Knautia arvensis L., Adonis vernalis L., Aster saggitifolius Willd., Taraxacum officinale L. Chelidonium majus L. The taxons were observed in Lublin (51008' - 51018' N and 21027' - 21041' E in the years 2001-2007. The blooming of species was determined at least for two vegetation seasons. During observations all flowers developed in one-hour intervals were counted. The diurnal dynamics of blooming differs among species and is modified by different endogenous and exogenous factors. The endogenous determinants of diurnal dynamics of blooming are morphological diversity of flowers (fertility or sterility within species or heterostyly. The different pattern of blooming succour different mechanisms which prevent self-pollination (Chaenomeles japonica Lindl., Knautia arvensis L.. The abiotic factors, such as day length and temperature during the vegetation season, influence the change in the process of diurnal dynamics of blooming (e. g. Taraxacum officinale, Chelidonium majus.

  2. Clinical features of Bloom syndrome and function of the causative gene, BLM helicase.

    Science.gov (United States)

    Kaneko, Hideo; Kondo, Naomi

    2004-05-01

    Bloom syndrome is a rare autosomal recessive genetic disorder characterized by growth deficiency, unusual facies, sun-sensitive telangiectatic erythema, immunodeficiency and predisposition to cancer. The causative gene for Bloom syndrome is BLM, which encodes the BLM RecQ helicase homolog protein. The first part of this review describes a long-term follow-up study of two Bloom syndrome siblings. Subsequently, the focus is placed on the functional domains of BLM. Laboratory diagnosis of Bloom syndrome by detecting mutations in BLM is laborious and impractical, unless there are common mutations in a population. Immunoblot and immunohistochemical analyses for the detection of the BLM protein using a polyclonal BLM antibody, which are useful approaches for clinical diagnosis of Bloom syndrome, are also described. In addition, a useful adjunct for the diagnosis of Bloom syndrome in terms of the BLM function is investigated, since disease cells must have the defective BLM helicase function. This review also discusses the nuclear localization signal of BLM, the proteins that interact with BLM and tumors originating from Bloom syndrome.

  3. Comparative Metagenomics of Toxic Freshwater Cyanobacteria Bloom Communities on Two Continents

    Energy Technology Data Exchange (ETDEWEB)

    Steffen, Morgan M [ORNL; Li, Zhou [ORNL; Effler, Chad [Department of Microbiology, University of Tennessee; Hauser, Loren John [ORNL; Boyer, Gergory [College of Environmental Science and Forestry, State University of New York, Syracuse; Wilhelm, Steven W [ORNL

    2012-01-01

    Toxic cyanobacterial blooms have persisted in freshwater systems around the world for centuries and appear to be globally increasing in frequency and severity. Toxins produced by bloom-associated cyanobacteria can have drastic impacts on the ecosystem and surrounding communities, and bloom biomass can disrupt aquatic food webs and act as a driver for hypoxia. Little is currently known regarding the genomic content of the Microcystis strains that form blooms or the companion heterotrophic community associated with bloom events. To address these issues, we examined the bloomassociated microbial communities in single samples from Lake Erie (North America), Lake Tai (Taihu, China), and Grand Lakes St. Marys (OH, USA) using comparative metagenomics. Together the Cyanobacteria and Proteobacteria comprised .90% of each bloom bacterial community sample, although the dominant phylum varied between systems. Relative to the existing Microcystis aeruginosa NIES 843 genome, sequences from Lake Erie and Taihu revealed a number of metagenomic islands that were absent in the environmental samples. Moreover, despite variation in the phylogenetic assignments of bloomassociated organisms, the functional potential of bloom members remained relatively constant between systems. This pattern was particularly noticeable in the genomic contribution of nitrogen assimilation genes. In Taihu, the genetic elements associated with the assimilation and metabolism of nitrogen were predominantly associated with Proteobacteria, while these functions in the North American lakes were primarily contributed to by the Cyanobacteria. Our observations build on an emerging body of metagenomic surveys describing the functional potential of microbial communities as more highly conserved than that of their phylogenetic makeup within natural systems.

  4. Species identification of mixed algal bloom in the Northern Arabian Sea using remote sensing techniques.

    Science.gov (United States)

    Dwivedi, R; Rafeeq, M; Smitha, B R; Padmakumar, K B; Thomas, Lathika Cicily; Sanjeevan, V N; Prakash, Prince; Raman, Mini

    2015-02-01

    Oceanic waters of the Northern Arabian Sea experience massive algal blooms during winter-spring (mid Feb-end Mar), which prevail for at least for 3 months covering the entire northern half of the basin from east to west. Ship cruises were conducted during winter-spring of 2001-2012 covering different stages of the bloom to study the biogeochemistry of the region. Phytoplankton analysis indicated the presence of green tides of dinoflagellate, Noctiluca scintillans (=N. miliaris), in the oceanic waters. Our observations indicated that diatoms are coupled and often co-exist with N. scintillans, making it a mixed-species ecosystem. In this paper, we describe an approach for detection of bloom-forming algae N. scintillans and its discrimination from diatoms using Moderate Resolution Imaging Spectroradiometer (MODIS)-Aqua data in a mixed-species environment. In situ remote sensing reflectance spectra were generated using Satlantic™ hyperspectral radiometer for the bloom and non-bloom waters. Spectral shapes of the reflectance spectra for different water types were distinct, and the same were used for species identification. Scatter of points representing different phytoplankton classes on a derivative plot revealed four diverse clusters, viz. N. scintillans, diatoms, non-bloom oceanic, and non-bloom coastal waters. The criteria developed for species discrimination were implemented on MODIS data and validated using inputs from a recent ship cruise conducted in March 2013.

  5. Intravascular optical coherence tomography light scattering artifacts: merry-go-rounding, blooming, and ghost struts

    Science.gov (United States)

    Mancuso, J. Jacob; Halaney, David L.; Elahi, Sahar; Ho, Derek; Wang, Tianyi; Ouyang, Yongjian; Dijkstra, Jouke; Milner, Thomas E.; Feldman, Marc D.

    2014-12-01

    We sought to elucidate the mechanisms underlying two common intravascular optical coherence tomography (IV-OCT) artifacts that occur when imaging metallic stents: "merry-go-rounding" (MGR), which is an increase in strut arc length (SAL), and "blooming," which is an increase in the strut reflection thickness (blooming thickness). Due to uncontrollable variables that occur in vivo, we performed an in vitro assessment of MGR and blooming in stented vessel phantoms. Using Xience V and Driver stents, we examined the effects of catheter offset, intimal strut coverage, and residual blood on SAL and blooming thickness in IV-OCT images. Catheter offset and strut coverage both caused minor MGR, while the greatest MGR effect resulted from light scattering by residual blood in the vessel lumen, with 1% hematocrit (Hct) causing a more than fourfold increase in SAL compared with saline (pResidual blood also resulted in blooming, with blooming thickness more than doubling when imaged in 0.5% Hct compared with saline (presidual blood in the imaging field, is the predominant cause of MGR. Light scattering also results in blooming, and a newly described artifact, three-dimensional-MGR, which results in "ghost struts" in B-scans.

  6. The Role of Cyanobacteria Blooms in Cholera Epidemic in Bangladesh

    Science.gov (United States)

    Sagir Ahmed, Md.; Raknuzzaman, Md.; Akther, Hafeza; Ahmed, Sumaiya

    A study was conducted on association of Vibrio cholerae with plankton specially emphasis on cyanobacteria in relation to some physico-chemical parameters in the River Buriganga, Dhaka, from January to December 2002. Monthly abundance of phytoplankton and zooplankton varied from 457 to 14166 and from 169 to 1055 individual L-1, respectively. Monthly average of faecal coliform in water, zooplankton and phytoplankton samples were 3.99x109, 4.54x103 and 4.28x102 (CFU L-1), respectively. During epidemics, toxigenic V. cholerae 01 and 0139 were isolated from the patients as well as from the surface water. V. cholerae 01 and 0139 were also isolated from plankton samples. More over, it was observed that ctx (cholera toxic) positive in water and phytoplankton samples of the river. A bloom of Oscillatoria sp. (1.6x104 individual L-1) occurred in the upper reaches of the River Buriganga in May 2002. Methanol-water extract of bloom sample was analyzed by high performance liquid chromatography with UV detection and Mass Spectrum (MS) detected microcystin-RR. Cyanobacteria are abundant in the aquatic environment of Bangladesh and it was established that V. cholerae maintain a symbiotic relationship with these algae particularly mucilaginous cyanobacteria. During epidemics, patients symptoms included diarrhea, vomiting and hemorrhagic enteritis and in severe cases hemorrhagic diarrhea. So, question has arisen that which is responsible, microcystins or cholera for death of cholera/diarrhea patients in Bangladesh. Future research should be directed to isolate microcystins and cholera toxins from the epidemic areas to clarify the fact.

  7. Biogeochemical implications of decomposing jellyfish blooms in a changing climate

    Science.gov (United States)

    Chelsky, Ariella; Pitt, Kylie A.; Welsh, David T.

    2015-03-01

    Jellyfish often exhibit 'boom and bust' population dynamics whereby they proliferate rapidly and then die en masse and decompose. The few studies that have investigated post-bloom processes have not studied how changing ocean conditions will alter rates of decomposition. Climate change will result in warmer and more acidic waters, and studies therefore need to consider these factors in concert to determine their combined effect on decomposition processes. To quantify the effect, we measured oxygen consumption and nutrient regeneration rates during decomposition of Catostylus mosaicus in mesocosms at current average summer pH and temperature (pH 8.0 and 27 °C) as well as conditions projected for year 2100 (pH 7.8 and 30 °C) and compared these fluxes to control mesocosms without jellyfish over 12 days. We hypothesised that rates of jellyfish decomposition, as measured by oxygen demand and nutrient regeneration, would be accelerated in the end-of-century treatments, compared to present day treatments. Overall decomposition rates were only slightly elevated under end-of-century conditions, and the difference was only significant for ammonium fluxes from 19 h until 43 h after the experiment commenced. The difference between treatments was much smaller than would be expected due to the temperature increase, based on theoretical modelling of jellyfish decomposition which predicts a Q10 of 4.28, or a 1.5 fold increase in decomposition rates. This highlights the importance of investigating net effects on decomposition rates, as simultaneous shifts in temperature and pH may not follow patterns predicted due to one stressor alone. Ultimately, these results suggest that rates of oxygen consumption and nutrient regeneration resulting from collapsed jellyfish blooms may not change drastically over the next 100 years.

  8. Loss of Bloom syndrome protein destabilizes human gene cluster architecture.

    Science.gov (United States)

    Killen, Michael W; Stults, Dawn M; Adachi, Noritaka; Hanakahi, Les; Pierce, Andrew J

    2009-09-15

    Bloom syndrome confers strong predisposition to malignancy in multiple tissue types. The Bloom syndrome patient (BLM) protein defective in the disease biochemically functions as a Holliday junction dissolvase and human cells lacking functional BLM show 10-fold elevated rates of sister chromatid exchange. Collectively, these phenomena suggest that dysregulated mitotic recombination drives the genomic instability underpinning the development of cancer in these individuals. Here we use physical analysis of the highly repeated, highly self-similar human ribosomal RNA gene clusters as sentinel biomarkers for dysregulated homologous recombination to demonstrate that loss of BLM protein function causes a striking increase in spontaneous molecular level genomic restructuring. Analysis of single-cell derived sub-clonal populations from wild-type human cell lines shows that gene cluster architecture is ordinarily very faithfully preserved under mitosis, but is so unstable in cell lines derived from BLMs as to make gene cluster architecture in different sub-clonal populations essentially unrecognizable one from another. Human cells defective in a different RecQ helicase, the WRN protein involved in the premature aging Werner syndrome, do not exhibit the gene cluster instability (GCI) phenotype, indicating that the BLM protein specifically, rather than RecQ helicases generally, holds back this recombination-mediated genomic instability. An ataxia-telangiectasia defective cell line also shows elevated rDNA GCI, although not to the extent of BLM defective cells. Genomic restructuring mediated by dysregulated recombination between the abundant low-copy repeats in the human genome may prove to be an important additional mechanism of genomic instability driving the initiation and progression of human cancer.

  9. Mesoscale variability of the summer bloom over the northern Ross Sea shelf: A tale of two banks

    Science.gov (United States)

    Kohut, Josh T.; Kustka, Adam B.; R. Hiscock, Michael; Lam, Phoebe J.; Measures, Chris; Milligan, Allen; White, Angelicque; Carvalho, Filipa; Hatta, Mariko; Jones, Bethan M.; Ohnemus, Daniel C.; Swartz, John M.

    2017-02-01

    Multi-year satellite records indicate an asymmetric spatial pattern in the summer bloom in the Northern Ross Sea, with the largest blooms over the shallows of Pennell Bank compared to Mawson Bank. In 2010-2011, high-resolution spatiotemporal in situ sampling focused on these two banks to better understand factors contributing to this pattern. Dissolved and particulate Fe profiles suggested similar surface water depletion of dissolved Fe on both banks. The surface sediments and velocity observations indicate a more energetic water column over Mawson Bank. Consequently, the surface mixed layer over Pennell Bank was more homogeneous and shallower. Over Mawson Bank we observed a thicker more homogeneous bottom boundary layer resulting from stronger tidal and sub-tidal currents. These stronger currents scour the seafloor resulting in sediments less likely to release additional sedimentary iron. Estimates of the quantum yield of photosynthesis and the initial slope of the photosynthesis-irradiance response were lower over Mawson Bank, indicating higher iron stress over Mawson Bank. Overall, the apparent additional sedimentary source of iron to, and longer surface residence time over Pennell Bank, as well as the reduced fluxes from the more isolated bottom mixed layer over Mawson Bank, sustain the observed asymmetric pattern across both banks.

  10. 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.

  11. Comparative metagenomics of toxic freshwater cyanobacteria bloom communities on two continents.

    Science.gov (United States)

    Steffen, Morgan M; Li, Zhou; Effler, T Chad; Hauser, Loren J; Boyer, Gregory L; Wilhelm, Steven W

    2012-01-01

    Toxic cyanobacterial blooms have persisted in freshwater systems around the world for centuries and appear to be globally increasing in frequency and severity. Toxins produced by bloom-associated cyanobacteria can have drastic impacts on the ecosystem and surrounding communities, and bloom biomass can disrupt aquatic food webs and act as a driver for hypoxia. Little is currently known regarding the genomic content of the Microcystis strains that form blooms or the companion heterotrophic community associated with bloom events. To address these issues, we examined the bloom-associated microbial communities in single samples from Lake Erie (North America), Lake Tai (Taihu, China), and Grand Lakes St. Marys (OH, USA) using comparative metagenomics. Together the Cyanobacteria and Proteobacteria comprised >90% of each bloom bacterial community sample, although the dominant phylum varied between systems. Relative to the existing Microcystis aeruginosa NIES 843 genome, sequences from Lake Erie and Taihu revealed a number of metagenomic islands that were absent in the environmental samples. Moreover, despite variation in the phylogenetic assignments of bloom-associated organisms, the functional potential of bloom members remained relatively constant between systems. This pattern was particularly noticeable in the genomic contribution of nitrogen assimilation genes. In Taihu, the genetic elements associated with the assimilation and metabolism of nitrogen were predominantly associated with Proteobacteria, while these functions in the North American lakes were primarily contributed to by the Cyanobacteria. Our observations build on an emerging body of metagenomic surveys describing the functional potential of microbial communities as more highly conserved than that of their phylogenetic makeup within natural systems.

  12. Comparative metagenomics of toxic freshwater cyanobacteria bloom communities on two continents.

    Directory of Open Access Journals (Sweden)

    Morgan M Steffen

    Full Text Available Toxic cyanobacterial blooms have persisted in freshwater systems around the world for centuries and appear to be globally increasing in frequency and severity. Toxins produced by bloom-associated cyanobacteria can have drastic impacts on the ecosystem and surrounding communities, and bloom biomass can disrupt aquatic food webs and act as a driver for hypoxia. Little is currently known regarding the genomic content of the Microcystis strains that form blooms or the companion heterotrophic community associated with bloom events. To address these issues, we examined the bloom-associated microbial communities in single samples from Lake Erie (North America, Lake Tai (Taihu, China, and Grand Lakes St. Marys (OH, USA using comparative metagenomics. Together the Cyanobacteria and Proteobacteria comprised >90% of each bloom bacterial community sample, although the dominant phylum varied between systems. Relative to the existing Microcystis aeruginosa NIES 843 genome, sequences from Lake Erie and Taihu revealed a number of metagenomic islands that were absent in the environmental samples. Moreover, despite variation in the phylogenetic assignments of bloom-associated organisms, the functional potential of bloom members remained relatively constant between systems. This pattern was particularly noticeable in the genomic contribution of nitrogen assimilation genes. In Taihu, the genetic elements associated with the assimilation and metabolism of nitrogen were predominantly associated with Proteobacteria, while these functions in the North American lakes were primarily contributed to by the Cyanobacteria. Our observations build on an emerging body of metagenomic surveys describing the functional potential of microbial communities as more highly conserved than that of their phylogenetic makeup within natural systems.

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

    Directory of Open Access Journals (Sweden)

    S. Sedigh Marvasti

    2015-07-01

    Full Text Available 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.

  14. Attribute-space connectivity and connected filters

    NARCIS (Netherlands)

    Wilkinson, Michael H.F.

    2007-01-01

    In this paper connected operators from mathematical morphology are extended to a wider class of operators, which are based on connectivities in higher dimensional spaces, similar to scale spaces, which will be called attribute-spaces. Though some properties of connected filters are lost, granulometr

  15. 南水水库水华发生机理和防治对策研究%Research on Occurring Mechanism and Control Measures of Algal Bloom in Nanshui Reservoir

    Institute of Scientific and Technical Information of China (English)

    王新伟

    2012-01-01

    Eutrophication and water bloom is the security risks of drinking water sources. The occurring time and incentives of algal bloom are different in different lakes and reservoirs. After analyzing the hydrological condition, water quality, algal composition and density, and meteorological characteristics during the bloom period of the Nanshui Reservoir, the mechanisms of cyanobateria outbreak were revealed. The high concentrations of total nitrogen caused by cage culture with high-density led to the cyanobacteria bloom even in dry and low temperature seasons while the other conditions are adequate such as slow water flow, continuous rise of temperature, sufficient Illumination. According to the incentives of water bloom, specific countermeasures for the control and treatment of algae bloom were proposed.%富营养化和水华爆发是饮用水水源地的安全隐患,不同湖泊和水库水华发生的时间、诱因不同.通过对广东省南水水库近几年水华发生期间的水文、水质、藻类、气象等特征进行分析,揭示了南水水库蓝藻发生的机理.由于高密度网箱养殖导致总氮浓度超标,在水库处于枯水季节,水体流动速度慢,温度虽然低但呈连续多日上升趋势、无雨且光照充足的条件下,容易发生蓝藻水华.针对水华发生的诱因,提出了控制和治理南水水库蓝藻爆发的具体对策措施.

  16. 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 parametric multidimensional scaling (nMDS) ordinations; cluster analysis powered by SIMPROF test also grouped the stations as BA and NBA.

  17. Phytoplankton spring and fall blooms in the North Atlantic in the 1980s and 2000s.

    OpenAIRE

    Martinez, Elodie; Antoine, David; D'Ortenzio, Fabrizio; de Boyer Montégut, Clément

    2011-01-01

    Phytoplankton chlorophyll-a (Chl) seasonal cycles of the North Atlantic are described using satellite ocean color observations covering the 1980s and the 2000s. The study region is where warmer SST and higher Chl in the 2000s as compared to the 1980s have been reported. It covers latitudes from 30 degrees N-50 degrees N and longitudes from 60 degrees W-0 degrees W, where two phytoplankton blooms take place: a spring bloom that follows stratification of upper layers, and a fall bloom due to nu...

  18. The X chromosome: does it have a role in Bloom syndrome, a genomic instability disorder?

    Science.gov (United States)

    Aslan, Deniz

    2014-01-01

    The Bloom syndrome, caused by mutations in a single gene [BLM (15q26.1)], is a rare genomic instability syndrome. Despite its autosomal recessive transmission, it shows a male dominance, suggesting the possibility of a subgroup with X-linked recessive inheritance. In view of the latest molecular developments achieved in the other genomic instability syndromes, the potential functions of the X chromosome in maintaining genomic stability, and particularly, the first clues of Bloom syndrome development by mechanisms other than the BLM, we suggest herein that the X chromosome should be investigated in Bloom syndrome.

  19. A case of Bloom syndrome with uncommon clinical manifestations confirmed on genetic testing.

    Science.gov (United States)

    Jian-Bing, Wu; Cheng-Rang, Li; Yi-Ping, Ma; Nan, Sheng; Hui, Li; Lin, Lin

    2016-02-01

    Bloom syndrome, a rare autosomal-recessive disorder, characteristically presents with photosensitivity, telangiectatic facial erythema, and growth deficiency. We present a case of Bloom syndrome with uncommon clinical manifestations including alopecia areata, eyebrow hair loss, flat nose, reticular pigmentation, and short sharpened distal phalanges with fingernails that were wider than they were long. We detected the Bloom syndrome gene, BLM, which is one of the members of the RecQ family of DNA helicases, and found changes in 2 heterozygous nucleotide sites in the patient as well as her father and mother.

  20. Bloom syndrome complicated by colonic cancer in a young Tunisian woman.

    Science.gov (United States)

    Benjazia, Elhem; Turki, Hajer; Atig, Amira; Khalifa, Mabrouk; Letaief, Amel; Bahri, Fethi; Braham, Ahlem

    2011-10-01

    Bloom syndrome (BS) is an autosomal recessive inherited disorder characterized by chromosomal instability leading to a high risk of cancer at an early age. The diagnosis should be considered in patients with short stature, photosensitivity, variable degrees of immunodeficiency, and hypogonadism. We report a 19-year-old woman, with history of dysmorphic features and recurrent infections. The diagnosis of bloom syndrome was made and confirmed cytogenetically at the age of 14 years. She developed a colon cancer revealed by venous thrombosis and anemia. She died after 15 days of the cancer diagnosis. This is the first registrated case of confirmed Bloom syndrome in Tunisian population.

  1. Bloom Filter在重复数据删除技术中应用的研究%Research on Application of Bloom Filter in Data Deduplication

    Institute of Scientific and Technical Information of China (English)

    陈春玲; 陈琳; 熊晶; 余瀚

    2016-01-01

    In order to alleviate the problem of the frequent access to storage device which caused by the indexes using in data deduplica-tion,data deduplication is deeply studied,making analysis and research on the application of Bloom Filter at the present situation of data deduplication and existing problems of the access of storage system performance and proposing a high-efficiency and optimal model based on Bloom Filter. Aiming at the situation that the probability of false positives is in the nature of Bloom Filters,an additional Bloom Filter is used to reduce false positive rate,achieving the purpose of reducing times of the access for storage system. In view of the situation that the system software errors may bring Bloom Filter false negative,single bit error checking mechanism is introduced to prevent it from happening,at the same time,it can reduce memory overhead. The simulation shows that the proposed method can balance the false posi-tive rate and the access of storage system costs. By introducing a judgment mechanism with complement Bloom Filter and single bit error checking mechanism,it can achieve the effects of the reducing of false positive rate and the access of storage system costs.%为了缓解存储系统中因为重复数据索引而引起的存储设备访问过于频繁的问题,深入研究重复数据删除技术,并针对目前重复数据删除技术中Bloom Filter的运用以及存在的存储设备访问性能问题进行分析和研究,提出一种基于Bloom Filter的高效去重优化模式。针对单一Bloom Filter固有的假阳性的缺陷,增加辅助Bloom Filter,从而减小误判率,达到减少存储设备访问次数的目的;针对因系统软件错误引起的Bloom Filter假阴性错误,引入单校验位的错误校验机制可以实现避免假阴性值存储的同时又能减小内存存储开销。仿真实验结果表明:改进方法能够兼顾Bloom Filter的误判率与存储设备访问开销问题。通过引入一种判断机制配合辅助Bloom

  2. 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

  3. Undifferentiated Connective Tissue Disease

    Science.gov (United States)

    ... Home Conditions Undifferentiated Connective Tissue Disease (UCTD) Undifferentiated Connective Tissue Disease (UCTD) Make an Appointment Find a Doctor ... L. Goldstein, MD, MMSc (February 01, 2016) Undifferentiated connective tissue disease (UCTD) is a systemic autoimmune disease. This ...

  4. Connective Tissue Disorders

    Science.gov (United States)

    Connective tissue is the material inside your body that supports many of its parts. It is the "cellular ... their work. Cartilage and fat are examples of connective tissue. There are over 200 disorders that impact connective ...

  5. The floral scents of Nymphaea subg. Hydrocallis (Nymphaeaceae), the New World night-blooming water lilies, and their relation with putative pollinators.

    Science.gov (United States)

    Maia, Artur Campos Dália; de Lima, Carla Teixeira; Navarro, Daniela Maria do Amaral Ferraz; Chartier, Marion; Giulietti, Ana Maria; Machado, Isabel Cristina

    2014-07-01

    Night-blooming water lilies are characterized by intense emission of floral VOCs. Their unique scent-oriented pollinators, cyclocephaline scarabs (Scarabaeidae, Cyclocephalini), are attracted to flowers that they use as reliable sources of food and as mating aggregation sites. Chemical analysis of floral scent samples of seven species of Nymphaea subg. Hydrocallis established remarkably simple fragrant blends, each of which was dominated by one or two prominent compounds that alone accounted for over 95% of total scent emission. A total of 22 VOCs were identified: aliphatics (9), C5-branched chain compounds (5) and aromatics (8). Anisole was the dominant constituent in the floral scents of Nymphaea amazonum subsp. amazonum, N. amazonum subsp. pedersenii and N. tenerinervia, whereas (methoxymethyl)benzene was the most abundant VOC in samples of N. lasiophylla and N. lingulata. Flowers of N. rudgeana and N. gardneriana emitted high amounts of methyl hexanoate and methyl 2-methylbutanoate. Comparisons of floral VOC composition including other day- and night-blooming species of Nymphaea and Victoria obtained from the literature evidenced disparities related to habitus. While flowers of day-blooming species mostly emit aromatic alcohols and ethers, nocturnal species are particularly rich in aromatic ethers, aliphatic esters and C5-branched chain esters. These findings strongly suggest that the floral scent composition within closely related Nymphaea and Victoria is linked to pollinator selection, and the putative role of floral VOCs in pollinator attractiveness is discussed.

  6. Synthesis and SAR studies of 5-(pyridin-4-yl)-1,3,4-thiadiazol-2-amine derivatives as potent inhibitors of Bloom helicase.

    Science.gov (United States)

    Rosenthal, Andrew S; Dexheimer, Thomas S; Gileadi, Opher; Nguyen, Giang H; Chu, Wai Kit; Hickson, Ian D; Jadhav, Ajit; Simeonov, Anton; Maloney, David J

    2013-10-15

    Human cells utilize a variety of complex DNA repair mechanisms in order to combat constant mutagenic and cytotoxic threats from both exogenous and endogenous sources. The RecQ family of DNA helicases, which includes Bloom helicase (BLM), plays an important function in DNA repair by unwinding complementary strands of duplex DNA as well as atypical DNA structures such as Holliday junctions. Mutations of the BLM gene can result in Bloom syndrome, an autosomal recessive disorder associated with cancer predisposition. BLM-deficient cells exhibit increased sensitivity to DNA damaging agents indicating that a selective BLM inhibitor could be useful in potentiating the anticancer activity of these agents. In this work, we describe the medicinal chemistry optimization of the hit molecule following a quantitative high-throughput screen of >355,000 compounds. These efforts lead to the identification of ML216 and related analogs, which possess potent BLM inhibition and exhibit selectivity over related helicases. Moreover, these compounds demonstrated cellular activity by inducing sister chromatid exchanges, a hallmark of Bloom syndrome.

  7. Minimum cost connection networks

    DEFF Research Database (Denmark)

    Hougaard, Jens Leth; Tvede, Mich

    . We use three axioms to characterize allocation rules that truthfully implement cost minimizing networks satisfying all connection demands in a game where: (1) a central planner announces an allocation rule and a cost estimation rule; (2) every agent reports her own connection demand as well as all...... connection costs; and, (3) the central planner selects a cost minimizing network satisfying reported connection demands based on estimated connection costs and allocates true connection costs of the selected network....

  8. Effect of monsoonal perturbations on the occurrence of phytoplankton blooms in a tropical bay

    Digital Repository Service at National Institute of Oceanography (India)

    Patil, J.S.; Anil, A.C.

    In this study, the influence of intraseasonal variations in rainfall and the resultant freshwater flux (monsoon perturbations) on phytoplankton bloom dynamics were evaluated by quantifying live phytoplankton at a fixed station (Dona Paula Bay, west...

  9. Study of Under-ice Blooms In the Chukchi Ecosystem (SUBICE) (HLY1401, EM122)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The primary objectives of SUBICE were to determine the spatial distribution of large under-ice phytoplankton blooms on the Chukchi Shelf and the physical mechanisms...

  10. 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...

  11. Algal-bloom control by allelopathy of aquatic macrophytes——A review

    Institute of Scientific and Technical Information of China (English)

    Hongying HU; Yu HONG

    2008-01-01

    Algal-bloom control is an important issue for water environment protection as it induces several nega-tive impacts on the lives of aquatic organisms, aquacul-ture, landscaping, and human health. The development of an environment-friendly, cost-effective, and convenient alternative for controlling algal bloom has gained much concern. Using the allelopathy of aquatic macrophytes as a novel and safe method for algal-bloom control is a promising alternative. This paper reviews the develop-ment and potential application about allelopathy of aquatic plants on algae, including the allelopathic research history, the potential research problems, the research methodology, and the reported aquatic macro-phytes and their inhibitory allelochemicals. Potential modes of inhibition action of allelochemicals on algae, possible ways for application, and future development directions of research on algal-bloom control by aquatic macrophytes were also presented.

  12. Impact of harmful algal blooms on several Lake Erie drinking water treatment facilities; methodology considerations

    Science.gov (United States)

    The propagation of cyanbacterial cells and their toxins were investigated at seven drinking water treatment plants (DWTPs) on Lake Erie were investigated with regards to harmful algal bloom (HAB) toxin concentrations, water quality variations in treatment plant influents, and pr...

  13. Status, Alert System, and Prediction of Cyanobacterial Bloom in South Korea

    Directory of Open Access Journals (Sweden)

    Ankita Srivastava

    2015-01-01

    Full Text Available Bloom-forming freshwater cyanobacterial genera pose a major ecological problem due to their ability to produce toxins and other bioactive compounds, which can have important implications in illnesses of humans and livestock. Cyanobacteria such as Microcystis, Anabaena, Oscillatoria, Phormidium, and Aphanizomenon species producing microcystins and anatoxin-a have been predominantly documented from most South Korean lakes and reservoirs. With the increase in frequency of such blooms, various monitoring approaches, treatment processes, and prediction models have been developed in due course. In this paper we review the field studies and current knowledge on toxin producing cyanobacterial species and ecological variables that regulate toxin production and bloom formation in major rivers (Han, Geum, Nakdong, and Yeongsan and reservoirs in South Korea. In addition, development of new, fast, and high-throughput techniques for effective monitoring is also discussed with cyanobacterial bloom advisory practices, current management strategies, and their implications in South Korean freshwater bodies.

  14. A first report on a bloom of the marine prymnesiophycean, Phaeocystis globosa from the Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Madhupratap, M.; Sawant, S.S.; Gauns, M.

    A thick bloom of the marine prymnesiophycean, Phaeocystis globosa was observed in the central Arabian Sea during the summer monsoon period (July-August, 1996). The cells were mostly in colonial form, embedded in gelatinous matrics. The cell diameter...

  15. Exploring the erodibility of sediments and harmful algal blooms in the Gulf of Maine

    Science.gov (United States)

    Butman, Bradford; Dickhudt, Patrick J.; Keafer, Bruce A.

    2012-01-01

    Investigators at the U.S. Geological Survey (USGS) are cooperating with scientists at Woods Hole Oceanographic Institution (WHOI) to investigate harmful algal blooms along the New England coast in the Gulf of Maine. These blooms are caused by cysts of the dinoflagellate Alexandrium fundyense that overwinter in the bottom sediments and germinate in spring. Depending on conditions such as temperature, light, nutrient levels, and currents, these single-celled organismscan create a bloom along the coast, called ‘red tides.’Shellfish that have ingested these cells in sufficient concentration can become toxic to humans and require that the shellfisheries be closed. After the spring bloom, the organisms form cysts that sink to the sea floor and are sequestered in the bottom sediments over the winter.

  16. Harmful algal blooms discovered during the Mote Monthly transect cruises, 1998 and 1999 (NODC Accession 0000532)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Harmful algal blooms of the toxic dinoflagellate, Karenia brevis, have caused massive fish kills in the Gulf of Mexico since the 1500's, with most occurrences on the...

  17. Pyrimidine pool imbalance induced by BLM helicase deficiency contributes to genetic instability in Bloom syndrome.

    Science.gov (United States)

    Chabosseau, Pauline; Buhagiar-Labarchède, Géraldine; Onclercq-Delic, Rosine; Lambert, Sarah; Debatisse, Michelle; Brison, Olivier; Amor-Guéret, Mounira

    2011-06-28

    Defects in DNA replication are associated with genetic instability and cancer development, as illustrated in Bloom syndrome. Features of this syndrome include a slowdown in replication speed, defective fork reactivation and high rates of sister chromatid exchange, with a general predisposition to cancer. Bloom syndrome is caused by mutations in the BLM gene encoding a RecQ helicase. Here we report that BLM deficiency is associated with a strong cytidine deaminase defect, leading to pyrimidine pool disequilibrium. In BLM-deficient cells, pyrimidine pool normalization leads to reduction of sister chromatid exchange frequency and is sufficient for full restoration of replication fork velocity but not the fork restart defect, thus identifying the part of the Bloom syndrome phenotype because of pyrimidine pool imbalance. This study provides new insights into the molecular basis of control of replication speed and the genetic instability associated with Bloom syndrome. Nucleotide pool disequilibrium could be a general phenomenon in a large spectrum of precancerous and cancer cells.

  18. A Model for Adapting. Bloom's Taxonomy to a Preschool Curriculum for the Gifted

    Science.gov (United States)

    Bailey, Donald B.; Leonard, Judith

    1977-01-01

    Presented is a rationale for the use of B. Bloom's taxonomy of educational objectives in the development of preschool curriculum units for the gifted and talented which translates taxonomical objectives into activities. (BB)

  19. Satellite remote sensing of harmful algal blooms (HABs) and a potential synthesized framework.

    Science.gov (United States)

    Shen, Li; Xu, Huiping; Guo, Xulin

    2012-01-01

    Harmful algal blooms (HABs) are severe ecological disasters threatening aquatic systems throughout the World, which necessitate scientific efforts in detecting and monitoring them. Compared with traditional in situ point observations, satellite remote sensing is considered as a promising technique for studying HABs due to its advantages of large-scale, real-time, and long-term monitoring. The present review summarizes the suitability of current satellite data sources and different algorithms for detecting HABs. It also discusses the spatial scale issue of HABs. Based on the major problems identified from previous literature, including the unsystematic understanding of HABs, the insufficient incorporation of satellite remote sensing, and a lack of multiple oceanographic explanations of the mechanisms causing HABs, this review also attempts to provide a comprehensive understanding of the complicated mechanism of HABs impacted by multiple oceanographic factors. A potential synthesized framework can be established by combining multiple accessible satellite remote sensing approaches including visual interpretation, spectra analysis, parameters retrieval and spatial-temporal pattern analysis. This framework aims to lead to a systematic and comprehensive monitoring of HABs based on satellite remote sensing from multiple oceanographic perspectives.

  20. Chytrid parasitism facilitates trophic transfer between bloom-forming cyanobacteria and zooplankton (Daphnia)

    Science.gov (United States)

    Agha, Ramsy; Saebelfeld, Manja; Manthey, Christin; Rohrlack, Thomas; Wolinska, Justyna

    2016-10-01

    Parasites are rarely included in food web studies, although they can strongly alter trophic interactions. In aquatic ecosystems, poorly grazed cyanobacteria often dominate phytoplankton communities, leading to the decoupling of primary and secondary production. Here, we addressed the interface between predator-prey and host-parasite interactions by conducting a life-table experiment, in which four Daphnia galeata genotypes were maintained on quantitatively comparable diets consisting of healthy cyanobacteria or cyanobacteria infected by a fungal (chytrid) parasite. In four out of five fitness parameters, at least one Daphnia genotype performed better on parasitised cyanobacteria than in the absence of infection. Further treatments consisting of purified chytrid zoospores and heterotrophic bacteria suspensions established the causes of improved fitness. First, Daphnia feed on chytrid zoospores which trophically upgrade cyanobacterial carbon. Second, an increase in heterotrophic bacterial biomass, promoted by cyanobacterial decay, provides an additional food source for Daphnia. In addition, chytrid infection induces fragmentation of cyanobacterial filaments, which could render cyanobacteria more edible. Our results demonstrate that chytrid parasitism can sustain zooplankton under cyanobacterial bloom conditions, and exemplify the potential of parasites to alter interactions between trophic levels.

  1. Flawed citation practices facilitate the unsubstantiated perception of a global trend toward increased jellyfish blooms

    KAUST Repository

    Sanz-Martín, Marina

    2016-06-24

    Speculation over a global rise in jellyfish populations has become widespread in the scientific literature, but until recently the purported ‘global increase’ had not been tested. Here we present a citation analysis of peer-reviewed literature to track the evolution of the current perception of increases in jellyfish and identify key papers involved in its establishment. Trend statements and citation threads were reviewed and arranged in a citation network. Trend statements were assessed according their degree of affirmation and spatial scale, and the appropriateness of the citations used to support statements was assessed. Analyses showed that 48.9% of publications misinterpreted the conclusions of cited sources, with a bias towards claiming jellyfish populations are increasing, with a single review having the most influence on the network. Collectively, these disparities resulted in a network based on unsubstantiated statements and citation threads. As a community, we must ensure our statements about scientific findings in general are accurately substantiated and carefully communicated such that incorrect perceptions, as in the case of jellyfish blooms, do not develop in the absence of rigorous testing. © 2016 John Wiley & Sons Ltd

  2. Hepatotoxicity of Microcystis aeruginosa Strains Growing as Blooms in Certain Eutrophic Ponds

    OpenAIRE

    Jha, Prabhat N.; Kumar, Anil; Kumar, Ashok; Singh, Dhananjay P.; Sinha, Rajeshwar P.; Tyagi, Madhu B.

    2006-01-01

    Critical assessment of five eutrophicated ponds of Varanasi city (India) revealed the presence of heavy blooms of cyanobacteria consisting mainly of Microcystis aeruginosa. Crude aqueous extracts of blooms as well as laboratory grown M. aeruginosa isolated from three ponds, namely Lakshmikund, Durgakund and Adityanagar showed toxicity in mouse bioassay test. Crude aqueous extracts from these samples caused death of test mice within 1h of administration (i.p.) with a LD50 of 60 mg/kg body weig...

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

    OpenAIRE

    Daniels, C.J.; Poulton, A. J.; Esposito, M; Paulsen, M. L.; Bellerby, R; M St John; Martin, A.P.

    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 by a lack of in situ observations of the phytoplankton community composition and its evolution during this critical period. We investigated the dynamics of the phytoplankton...

  4. Cellular defects caused by hypomorphic variants of the Bloom syndrome helicase gene BLM

    OpenAIRE

    Shastri, Vivek M.; Schmidt, Kristina H.

    2015-01-01

    Abstract Background Bloom syndrome is an autosomal recessive disorder characterized by extraordinary cancer incidence early in life and an average life expectancy of ~27 years. Premature stop codons in BLM , which encodes a DNA helicase that functions in DNA double‐strand‐break repair, make up the vast majority of Bloom syndrome mutations, with only 13 single amino acid changes identified in the syndrome. Sequencing projects have identified nearly one hundred single nucleotide variants in BLM...

  5. Applying the Revised Bloom's Taxonomy to a medical-surgical nursing lesson.

    Science.gov (United States)

    Su, Whei Ming; Osisek, Paul J; Starnes, Beth

    2004-01-01

    The Revised Bloom's Taxonomy provides a 2-dimensional framework for classifying cognitive learning. Classifying learning objectives by knowledge type in relation to cognitive process helps educators obtain a better understanding about intended learning, and enables them to design appropriate instruction and assessment methods. The authors demonstrate use of the Revised Bloom's Taxonomy to achieve congruence among intended learning, instructional activities, and assessment methods while teaching diagnostic reasoning for clients with myocardial infarction.

  6. How hydrodynamics control algal blooms in the Ythan estuary, Scotland

    Science.gov (United States)

    Champangern, Khruewan; Hoey, Trevor; Thomas, Rhian

    2016-04-01

    The Ythan estuary, northeast Scotland, was designated in 2000 as a Nitrate Vulnerable Zone (NVZ) under the European Commission (EC) Nitrates Directive. Much of the catchment is intensively farmed and water quality has been adversely affected by nutrients from agricultural fertilizers. As a result, algal mats develop annually on tidal flats where sediment from upstream and from the adjacent dune systems is deposited. Understanding the patterns of water (river and ocean) circulation in the estuary as well as understanding how nutrients and sediments are transported in the estuary is crucial for understanding the role of several factors (elevation; sediment characteristics; nutrient flux) control the locations and scale of annual algal blooms. In order to understand those controls, study of interactions between hydrodynamic factors and water quality, in particular chlorophyll levels, at different time scales has been carried out. The results from the study reveal complex seasonal and event-scale relationships of river flow with the amount of chlorophyll, which provide an initial comprehension of controls over the concentrations of chlorophyll in the estuary. The concentration of chlorophyll changes, whether increasing or decreasing, with regards to changes in river flow. During high flow events, high amounts of chlorophyll are found when the tide is low. During low flow events, high amounts of chlorophyll are found at high tides. These phenomena reveal that both river flow and tidal cycle affect the amount of chlorophyll in the estuary. In addition, the Delft3d flow model, which has been extensively applied to many coastal and estuarine studies is used to simulate hydrodynamic patterns in the estuary during high flow and low flow events. The model is composed of 36,450 fine resolution grids and the upstream/ downstream boundary that represents water level is based on time-series data from river flow and tidal measurements. The bathymetry used for the model domain is

  7. Leads in Arctic pack ice enable early phytoplankton blooms below snow-covered sea ice

    Science.gov (United States)

    Assmy, Philipp; Fernández-Méndez, Mar; Duarte, Pedro; Meyer, Amelie; Randelhoff, Achim; Mundy, Christopher J.; Olsen, Lasse M.; Kauko, Hanna M.; Bailey, Allison; Chierici, Melissa; Cohen, Lana; Doulgeris, Anthony P.; Ehn, Jens K.; Fransson, Agneta; Gerland, Sebastian; Hop, Haakon; Hudson, Stephen R.; Hughes, Nick; Itkin, Polona; Johnsen, Geir; King, Jennifer A.; Koch, Boris P.; Koenig, Zoe; Kwasniewski, Slawomir; Laney, Samuel R.; Nicolaus, Marcel; Pavlov, Alexey K.; Polashenski, Christopher M.; Provost, Christine; Rösel, Anja; Sandbu, Marthe; Spreen, Gunnar; Smedsrud, Lars H.; Sundfjord, Arild; Taskjelle, Torbjørn; Tatarek, Agnieszka; Wiktor, Jozef; Wagner, Penelope M.; Wold, Anette; Steen, Harald; Granskog, Mats A.

    2017-01-01

    The Arctic icescape is rapidly transforming from a thicker multiyear ice cover to a thinner and largely seasonal first-year ice cover with significant consequences for Arctic primary production. One critical challenge is to understand how productivity will change within the next decades. Recent studies have reported extensive phytoplankton blooms beneath ponded sea ice during summer, indicating that satellite-based Arctic annual primary production estimates may be significantly underestimated. Here we present a unique time-series of a phytoplankton spring bloom observed beneath snow-covered Arctic pack ice. The bloom, dominated by the haptophyte algae Phaeocystis pouchetii, caused near depletion of the surface nitrate inventory and a decline in dissolved inorganic carbon by 16 ± 6 g C m‑2. Ocean circulation characteristics in the area indicated that the bloom developed in situ despite the snow-covered sea ice. Leads in the dynamic ice cover provided added sunlight necessary to initiate and sustain the bloom. Phytoplankton blooms beneath snow-covered ice might become more common and widespread in the future Arctic Ocean with frequent lead formation due to thinner and more dynamic sea ice despite projected increases in high-Arctic snowfall. This could alter productivity, marine food webs and carbon sequestration in the Arctic Ocean.

  8. Eco-evolutionary feedbacks between private and public goods: evidence from toxic algal blooms.

    Science.gov (United States)

    Driscoll, William W; Hackett, Jeremiah D; Ferrière, Régis

    2016-01-01

    The importance of 'eco-evolutionary feedbacks' in natural systems is currently unclear. Here, we advance a general hypothesis for a particular class of eco-evolutionary feedbacks with potentially large, long-lasting impacts in complex ecosystems. These eco-evolutionary feedbacks involve traits that mediate important interactions with abiotic and biotic features of the environment and a self-driven reversal of selection as the ecological impact of the trait varies between private (small scale) and public (large scale). Toxic algal blooms may involve such eco-evolutionary feedbacks due to the emergence of public goods. We review evidence that toxin production by microalgae may yield 'privatised' benefits for individual cells or colonies under pre- and early-bloom conditions; however, the large-scale, ecosystem-level effects of toxicity associated with bloom states yield benefits that are necessarily 'public'. Theory predicts that the replacement of private with public goods may reverse selection for toxicity in the absence of higher level selection. Indeed, blooms often harbor significant genetic and functional diversity: bloom populations may undergo genetic differentiation over a scale of days, and even genetically similar lineages may vary widely in toxic potential. Intriguingly, these observations find parallels in terrestrial communities, suggesting that toxic blooms may serve as useful models for eco-evolutionary dynamics in nature. Eco-evolutionary feedbacks involving the emergence of a public good may shed new light on the potential for interactions between ecology and evolution to influence the structure and function of entire ecosystems.

  9. Dinoflagellate Bloom of Karenia mikimotoi along the Southeast Arabian Sea, Bordering Western India

    Directory of Open Access Journals (Sweden)

    R. S. Robin

    2013-01-01

    Full Text Available A harmful algal bloom (HAB occurred along the southeast Arabian Sea, bordering Western India, during September to November 2004. This bloom was unique in the region in terms of its large spatial extent, and the trend was weakened towards November. Mass mortality of fish, emanation of noxious odour, and respiratory problems among the children on the coastal stretch were noticed. The phytoplankton species Gymnodiniium, class Dinophyceae bloom accounted for 98% of the standing crop. The bloom Karenia mikimotoi showed a maximum density of 19.37×104 cells L−1 and 18.94×104 cells L−1 at nearshore and offshore, respectively. The remotely sensed chlorophyll a (Chl a data from seaWiFS, sea surface temperature (SST from advanced very high resolution radiometer (AVHRR, rainfall from tropical rainfall measuring Mission (TRMM, and Sea winds from QuickSCAT reflected the bloom due to Karenia mikimotoi, suggesting the advection process at the coastal waters. The release of toxins specifically the neurotoxic shellfish poisoning (NSP and azaspiracid shellfish poisoning (AZP from the bloom was assessed by chemical and mouse bioassay of the extract from mussel Perna indica, showing negative results. These indicate that asphyxiation and abnormal mucus secreted by the K. mikimotoi led to clogging of gills that accentuated the mass fish kills.

  10. Leads in Arctic pack ice enable early phytoplankton blooms below snow-covered sea ice

    Science.gov (United States)

    Assmy, Philipp; Fernández-Méndez, Mar; Duarte, Pedro; Meyer, Amelie; Randelhoff, Achim; Mundy, Christopher J.; Olsen, Lasse M.; Kauko, Hanna M.; Bailey, Allison; Chierici, Melissa; Cohen, Lana; Doulgeris, Anthony P.; Ehn, Jens K.; Fransson, Agneta; Gerland, Sebastian; Hop, Haakon; Hudson, Stephen R.; Hughes, Nick; Itkin, Polona; Johnsen, Geir; King, Jennifer A.; Koch, Boris P.; Koenig, Zoe; Kwasniewski, Slawomir; Laney, Samuel R.; Nicolaus, Marcel; Pavlov, Alexey K.; Polashenski, Christopher M.; Provost, Christine; Rösel, Anja; Sandbu, Marthe; Spreen, Gunnar; Smedsrud, Lars H.; Sundfjord, Arild; Taskjelle, Torbjørn; Tatarek, Agnieszka; Wiktor, Jozef; Wagner, Penelope M.; Wold, Anette; Steen, Harald; Granskog, Mats A.

    2017-01-01

    The Arctic icescape is rapidly transforming from a thicker multiyear ice cover to a thinner and largely seasonal first-year ice cover with significant consequences for Arctic primary production. One critical challenge is to understand how productivity will change within the next decades. Recent studies have reported extensive phytoplankton blooms beneath ponded sea ice during summer, indicating that satellite-based Arctic annual primary production estimates may be significantly underestimated. Here we present a unique time-series of a phytoplankton spring bloom observed beneath snow-covered Arctic pack ice. The bloom, dominated by the haptophyte algae Phaeocystis pouchetii, caused near depletion of the surface nitrate inventory and a decline in dissolved inorganic carbon by 16 ± 6 g C m−2. Ocean circulation characteristics in the area indicated that the bloom developed in situ despite the snow-covered sea ice. Leads in the dynamic ice cover provided added sunlight necessary to initiate and sustain the bloom. Phytoplankton blooms beneath snow-covered ice might become more common and widespread in the future Arctic Ocean with frequent lead formation due to thinner and more dynamic sea ice despite projected increases in high-Arctic snowfall. This could alter productivity, marine food webs and carbon sequestration in the Arctic Ocean. PMID:28102329

  11. 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. 

  12. Assessment of microcystis bloom toxicity associated with wildlife mortality in the Kruger National Park, South Africa.

    Science.gov (United States)

    Masango, Mxolisi G; Myburgh, Jan G; Labuschagne, Leonie; Govender, Danny; Bengis, Roy G; Naicker, Dharmarai

    2010-01-01

    Based on previous necropsy results, Microcystis blooms in constructed water impoundments in the Kruger National Park (KNP) have been identified as a cause of wildlife mortality. In response to wildlife mortality during 2007, water samples, containing algal bloom material, were collected during February 2007 and July 2007 from four dams (Nhlanganzwani, Mpanamana, Makhohlola, and Sunset) in the southeastern part of the KNP as part of the follow-up investigation. The toxicity of the Microcystis blooms was determined using the enzyme-linked immunosorbent assay (ELISA), protein phosphatase inhibition (PPI) assay, mouse bioassay, and African sharptooth catfish (Clarias gariepinus) primary hepatocytes. Both the ELISA and PPI assays indicated that the water sample collected during February 2007 from the Nhlanganzwani Dam, and samples collected from the Nhlanganzwani and Sunset dams in June 2007, were toxic. These dams, exhibiting the toxic Microcystis blooms, were also associated with the wildlife mortality. Mice injected intraperitoneally with water samples from Nhlanganzwani Dam (February 2007) induced hepatotoxicity and mortality within 1 hr. Primary hepatocytes from the sharptooth catfish exposed to samples from these dams gave similar results. This laboratory investigation and results strongly incriminate the toxic Microcystis blooms as the cause of the wildlife mortality. Eutrophication and bloom formation appear to have been the consequence of the high numbers of hippopotami (Hippopotamus amphibius) in specific dams.

  13. Export and mesopelagic particle flux during a North Atlantic spring diatom bloom

    Science.gov (United States)

    Martin, Patrick; Lampitt, Richard S.; Jane Perry, Mary; Sanders, Richard; Lee, Craig; D'Asaro, Eric

    2011-04-01

    Spring diatom blooms are important for sequestering atmospheric CO 2 below the permanent thermocline in the form of particulate organic carbon (POC). We measured downward POC flux during a sub-polar North Atlantic spring bloom at 100 m using thorium-234 ( 234Th) disequilibria, and below 100 m using neutrally buoyant drifting sediment traps. The cruise followed a Lagrangian float, and a pronounced diatom bloom occurred in a 600 km 2 area around the float. Particle flux was low during the first three weeks of the bloom, between 10 and 30 mg POC m -2 d -1. Then, nearly 20 days after the bloom had started, export as diagnosed from 234Th rose to 360-620 mg POC m -2 d -1, co-incident with silicate depletion in the surface mixed layer. Sediment traps at 600 and 750 m depth collected 160 and 150 mg POC m -2 d -1, with a settled volume of particles of 1000-1500 mL m -2 d -1. This implies that 25-43% of the 100 m POC export sank below 750 m. The sinking particles were ungrazed diatom aggregates that contained transparent exopolymer particles (TEP). We conclude that diatom blooms can lead to substantial particle export that is transferred efficiently through the mesopelagic. We also present an improved method of calibrating the Alcian Blue solution against Gum Xanthan for TEP measurements.

  14. 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.

  15. Off-flavor compounds from decaying cyanobacterial blooms of Lake Taihu

    Institute of Scientific and Technical Information of China (English)

    Zhimei Ma; Yuan Niu; Ping Xie; Jun Chen; Min Tao; Xuwei Deng

    2013-01-01

    The effect of cyanobacterial bloom decay on water quality and the complete degradation of cyanobacterial blooms in a short period were examined by an enclosure experiment in Gonghu Bay of Lake Taihu,China.Water quality parameters as well as taste and odor compounds during the breakdown of cyanobacterial blooms were measured.Results showed that the decay of cyanobacterial blooms caused anoxic water conditions,decreased pH,and increased nutrient loading to the lake water.The highest concentrations of dimethyl sulfide (DMS),dimethyl trisulfide (DMTS),and β-cyclocitral were observed in the anoxic water,at 62331.8,12413.3,and 1374.9 ng/L,respectively.2-Methylisoborneol was dominant during the live growth phase of cyanobacterial blooms,whereas DMS and DMTS were dominant during the decomposition phase.Dissolved oxygen,pH,and chlorophyll a were negatively correlated with DMS,DMTS,and β-cyclocitral,whereas total phosphorus,total nitrogen,and ammonium (NH4+-N) were positively correlated with DMS,DMTS,β-cyclocitral,and β-ionone.The experimental results suggested that preventing the anaerobic decomposition of cyanobactedal blooms is an important strategy against the recurrence of a malodor crisis in Lake Taihu.

  16. Satellite Detection of Phaeocystis Globosa Blooms in the Eastern English Channel

    Science.gov (United States)

    Lubac, B.; Loisel, H.; Poteau, A.; Guiselin, N.

    2006-12-01

    Detecting phytoplankton species from remote sensing is essential to map and monitor algal blooms in coastal waters, but stays a challenge because of the interference of suspended sediments and dissolved organic matter with the phytoplankton signal. In the eastern English Channel and the south North Sea, a more or less intensive bloom of prymnesiophyceae Phaeocystis globosa occurs almost every spring and follows generally a first bloom of diatoms. From hyperspectral radiometric measurements (TRIOS; 350-950 nm, with a 3 nm resolution) concurrently performed with absorption, and backscattering measurements, as well as with phytoplankton species diversity determination, a spectral signature based on a derivative analysis was observed to discriminate the P. globosa blooms. In this study, we develop a multispectral approach to detect P. globosa blooms and investigate the possibility to apply this method to "ocean color" sensors (SeaWIFS). Then, we examine the impact of the bloom of P. globosa on the restitution of ocean color standard products, in particularly the chlorophyll a concentration (Chl), and examine new approaches to improve the restitution of Chl in this complex coastal environment.

  17. Optical properties of algal blooms in an eutrophicated coastal area and its relevance to remote sensing

    Science.gov (United States)

    Astoreca, Rosa; Rousseau, Veronique; Ruddick, Kevin; Van Mol, Barbara; Parent, Jean-Yves; Lancelot, Christiane

    2005-08-01

    The Southern Bight of the North Sea is characterised by a large influence of river inputs, which results in eutrophication of the area. High concentrations of plankton biomass and suspended matter have been reported for this area, in relation with blooms of different species and resuspension of bottom sediments. In spring the haptophyte Phaeocystis globosa blooms throughout the area reaching up to 30 mg Chlorophyll m-3 or more nearshore. This event is followed in June by red tides of the dinoflagellate Noctiluca scintillans. These blooms are concurrent with different species of diatoms. The strong optical signature of these blooms is clear to human observers making them potentially detectable in satellite imagery. As a first step in this direction, sampling has been carried out in the area, during Phaeocystis and Noctiluca blooms in 2003 and 2004. Phytoplankton pigments and inherent optical properties (particle, detrital and phytoplankton absorption) have been measured spectrophotometrically, and in situ using an ac-9 for total absorption and particle scattering. Field data were compared with optical properties of pure species obtained in laboratory. In parallel, water-leaving reflectance has been also measured. In this paper we characterise the optical signatures of diatoms, Phaeocystis and Noctiluca and their contribution to total absorption. The impact on water-leaving reflectance spectra is evaluated; in order to assess the conditions in which remote sensing can provide information for monitoring the timing, extent and magnitude of blooms in this coastal area.

  18. Visualizing neuronal network connectivity with connectivity pattern tables

    Directory of Open Access Journals (Sweden)

    Eilen Nordlie

    2010-01-01

    Full Text Available Complex ideas are best conveyed through well-designed illustrations. Up to now, computational neuroscientists have mostly relied on box-and-arrow diagrams of even complex neuronal networks, often using ad hoc notations with conflicting use of symbols from paper to paper. This significantly impedes the communication of ideas in neuronal network modeling. We present here Connectivity Pattern Tables (CPTs as a clutter-free visualization of connectivity in large neuronal networks containing two-dimensional populations of neurons. CPTs can be generated automatically from the same script code used to create the actual network in the NEST simulator. Through aggregation, CPTs can be viewed at different levels, providing either full detail or summary information. We also provide the open source ConnPlotter tool as a means to create connectivity pattern tables.

  19. Recurrent jellyfish blooms are a consequence of global oscillations.

    Science.gov (United States)

    Condon, Robert H; Duarte, Carlos M; Pitt, Kylie A; Robinson, Kelly L; Lucas, Cathy H; Sutherland, Kelly R; Mianzan, Hermes W; Bogeberg, Molly; Purcell, Jennifer E; Decker, Mary Beth; Uye, Shin-ichi; Madin, Laurence P; Brodeur, Richard D; Haddock, Steven H D; Malej, Alenka; Parry, Gregory D; Eriksen, Elena; Quiñones, Javier; Acha, Marcelo; Harvey, Michel; Arthur, James M; Graham, William M

    2013-01-15

    A perceived recent increase in global jellyfish abundance has been portrayed as a symptom of degraded oceans. This perception is based primarily on a few case studies and anecdotal evidence, but a formal analysis of global temporal trends in jellyfish populations has been missing. Here, we analyze all available long-term datasets on changes in jellyfish abundance across multiple coastal stations, using linear and logistic mixed models and effect-size analysis to show that there is no robust evidence for a global increase in jellyfish. Although there has been a small linear increase in jellyfish since the 1970s, this trend was unsubstantiated by effect-size analysis that showed no difference in the proportion of increasing vs. decreasing jellyfish populations over all time periods examined. Rather, the strongest nonrandom trend indicated jellyfish populations undergo larger, worldwide oscillations with an approximate 20-y periodicity, including a rising phase during the 1990s that contributed to the perception of a global increase in jellyfish abundance. Sustained monitoring is required over the next decade to elucidate with statistical confidence whether the weak increasing linear trend in jellyfish after 1970 is an actual shift in the baseline or part of an oscillation. Irrespective of the nature of increase, given the potential damage posed by jellyfish blooms to fisheries, tourism, and other human industries, our findings foretell recurrent phases of rise and fall in jellyfish populations that society should be prepared to face.

  20. Thermomechanical Behavior in Continuous Bloom Casting with Different Mold Tapers

    Institute of Scientific and Technical Information of China (English)

    LUO Xin; CHEN Yong; SHEN Houfa

    2008-01-01

    A two-dimensional finite element model was used to analyze the thermal and mechanical behavior dunng solidification of the strand in a continuous bloom casting mold.The coupled heat transfer and defermation were analyzed to simulate the formation of the air gap between the mold and the strand.The model was used to investigate the influence of mold taper on the temperature and stress distributions in the strand.The results show that the air gap mainly forms around the strand corner,causing a hoRer and thinner solidifying shell in this region.The mold taper partially compensates for the strand shell shnnkage and reduces the infiuence of the air gap on the heat transfer.The mold taper compresses the shell and changes the stress state around the stmnd comer region.As the strand moves down into the mold,the mold constraint causes compressive stress beneath the comer surface.which reduces the hot tear that forms on the strand.

  1. Biological control of harmful algal blooms: A modelling study

    Science.gov (United States)

    Solé, Jordi; Estrada, Marta; Garcia-Ladona, Emilio

    2006-07-01

    A multispecies dynamic simulation model (ERSEM) was used to examine the influence of allelopathic and trophic interactions causing feeding avoidance by predators, on the formation of harmful algal blooms, under environmental scenarios typical of a Mediterranean harbour (Barcelona). The biological state variables of the model included four functional groups of phytoplankton (diatoms, toxic and non-toxic flagellates and picophytoplankton), heterotrophic flagellates, micro- and mesozooplankton and bacteria. The physical-chemical forcing (irradiance, temperature and major nutrient concentrations) was based on an actual series of measurements taken along a year cycle in the Barcelona harbour. In order to evaluate potential effects of advection, some runs were repeated after introducing a biomass loss term. Numerical simulations showed that allelopathic effects of a toxic alga on a non-toxic but otherwise similar competitor did not have appreciable influence on the dynamics of the system. However, induction of avoidance of the toxic alga by predators, which resulted on increased predation pressure on other algal groups had a significant effect on the development of algal and predator populations. The presence of advection overrided the effect of these interactions and only allowed organisms with sufficiently high potential growth rates to thrive.

  2. Augmented cell death with Bloom syndrome helicase deficiency.

    Science.gov (United States)

    Kaneko, Hideo; Fukao, Toshiyuki; Kasahara, Kimiko; Yamada, Taketo; Kondo, Naomi

    2011-01-01

    Bloom syndrome (BS) is a rare autosomal genetic disorder characterized by lupus-like erythematous telangi-ectasias of the face, sun sensitivity, infertility, stunted growth, upper respiratory infection, and gastrointestinal infections commonly associated with decreased immuno-globulin levels. The syndrome is associated with immuno-deficiency of a generalized type, ranging from mild and essentially asympto-matic to severe. Chromosomal abnormalities are hallmarks of the disorder, and high frequencies of sister chromatid exchanges and quadriradial configurations in lymphocytes and fibroblasts are diagnostic features. BS is caused by mutations in BLM, a member of the RecQ helicase family. We determined whether BLM deficiency has any effects on cell growth and death in BLM-deficient cells and mice. BLM-deficient EB-virus-transformed cell lines from BS patients and embryonic fibroblasts from BLM-/- mice showed slower growth than wild-type cells. BLM-deficient cells showed abnormal p53 protein expression after irradiation. In BLM-/- mice, small body size, reduced number of fetal liver cells and increased cell death were observed. BLM deficiency causes the up-regulation of p53, double-strand break and apoptosis, which are likely observed in irradiated control cells. Slow cell growth and increased cell death may be one of the causes of the small body size associated with BS patients.

  3. Real time observations of coastal algal blooms by an early warning system

    Science.gov (United States)

    Lee, J. H. W.; Hodgkiss, I. J.; Wong, K. T. M.; Lam, I. H. Y.

    2005-10-01

    In eutrophic sub-tropical coastal waters around Hong Kong, phytoplankton or unicellular microalgae can grow rapidly to very high concentrations under favourable environmental conditions. These harmful algal blooms (HABs) have led to massive fish kills, hypoxia, and beach closures. However, to date the causality and mechanism of coastal algal blooms are still poorly understood. A remotely controlled autonomous real time field monitoring system has been developed to continuously track the changes in chlorophyll fluorescence, dissolved oxygen and other hydro-meteorological variables at two representative mariculture zones. The system can give an alarm when a bloom is detected, so that timely manual water quality sampling can be carried out to supplement the telemetric data. During 2000-2003, the system has successfully tracked 19 algal blooms. In the shallow weakly flushed coastal water (depth 7-10 m, tidal current 5-19 cm s -1), the bloom is short-lived, typically lasting a few days to over a week, with chlorophyll and DO concentrations in the range of 20-40 mg m -3 and 2-15 g m -3, respectively. It is found that: (1) the chlorophyll concentration is strongly correlated with its past values in the previous week, suggesting an auto-regressive type of algal dynamics; (2) the dissolved oxygen can reach highly super-saturated levels (12 g m -3) during a diatom bloom, and decreases to below 4 g m -3 at the tail of the growth phase; (3) in contrast, a dinoflagellate bloom is characterized by a much more pronounced vertical structure. Diel vertical migration and aggregation to dense layers are clearly observed. Significant dissolved oxygen consumption is associated with the migration, resulting in DO drops by as much as 6 g m -3 during the bloom; (4) the predominance of diatoms and dinoflagellates at the two sites can be explained in terms of the different hydrographic and nutrient conditions (the N:P ratio). Net algal growth rate, sinking and swimming velocities are

  4. Modelling green macroalgal blooms on the coasts of Brittany, France to enhance water quality management

    Science.gov (United States)

    Perrot, Thierry; Rossi, Nadège; Ménesguen, Alain; Dumas, Franck

    2014-04-01

    First recorded in the 1970s, massive green macroalgal blooms have since become an annual recurrence in Brittany, France. Eutrophication (in particular to anthropogenic nitrogen input) has been identified as the main factor controlling Ulva ‘green tide' events. In this study, we modelled Ulva proliferation using a two-dimensional model by coupling hydrodynamic and biological models (coined ‘MARS-Ulves') for five sites along the Brittany coastline (La Fresnaye Bay, Saint-Brieuc Bay, Lannion Bay, Guissény Bay and Douarnenez Bay). Calibration of the biological model was mainly based on the seasonal variation of the maximum nitrogen uptake rate (VmaxN) and the half-saturation constant for nitrogen (KN) to reproduce the internal nutrient quotas measured in situ for each site. In each bay, model predictions were in agreement with observed algal coverage converted into biomass. A numerical tracking method was implemented to identify the contribution of the rivers that empty into the study bays, and scenarios of decreases in nitrate concentration in rivers were simulated. Results from numerical nitrogen tracking highlighted the main nitrogen sources of green tides and also showed that each river contributes locally to green tides. In addition, dynamic modelling showed that the nitrate concentrations in rivers must be limited to between 5 and 15 mg l- 1, depending on the bay, to reduce Ulva biomass by half on the coasts. The three-step methodology developed in this study (analysing total dissolved inorganic nitrogen flux from rivers, tracking nitrogen sources in Ulva and developing scenarios for reducing nitrogen) provides qualitative and quantitative guidelines for stakeholders to define specific nitrogen reduction targets for better environmental management of water quality.

  5. 基于Bloom filter引擎的分布式网络取证系统%Distributed network forensics system based on Bloom filter engine

    Institute of Scientific and Technical Information of China (English)

    赵骞; 崔益民; 邹涛

    2009-01-01

    针对目前网络取证的特点和技术挑战,提出和设计了一种基于Bloom filter引擎的分布式网络取证系统.该系统以Bloom filter引擎为核心,能够实时的对网络原始数据进行过滤,映射压缩和存储,捕获完整的证据,节省存储空间,有效支持网络取证的事后分析查询.%Aiming at technical challenges of network forensics at present,a distributed network forensics system based on the Bloom filter engine was proposed and designed.The system with the Bloom filter engine as the core can filtrate,memory-map raw network data for compression,capture complete evidence,save storage space,and help with post-event investigation of network forensics.

  6. Monitoring of Harmful Algal Blooms through Drinking Water Treatment Facilities Located on Lake Erie in the 2014 and 2015 Bloom Seasons

    Science.gov (United States)

    A number of drinking water treatment plants on Lake Erie have supplied water samples on a monthly basis for analysis related to the occurrence of harmful algal blooms (HABs). General water quality parameters including total organic carbon (TOC), orthophosphate, and chlorophyll-A ...

  7. Early spawning of Antarctic krill in the Scotia Sea is fuelled by “superfluous” feeding on non-ice associated phytoplankton blooms

    Science.gov (United States)

    Schmidt, Katrin; Atkinson, Angus; Venables, Hugh J.; Pond, David W.

    2012-01-01

    The spawning success of Antarctic krill ( Euphausia superba) is generally assumed to depend on substantial winter sea ice extent, as ice biota can serve as a food source during winter/spring and the seasonal ice melt conditions the upper water column for extensive phytoplankton blooms. However, direct observations during spring are rare. Here we studied krill body condition and maturity stage in relation to feeding (i.e. stomach fullness, diet, absorption of individual fatty acids and defecation rate) across the Scotia Sea in November 2006. The phytoplankton concentrations were low at the marginal ice zone (MIZ) in the southern Scotia Sea (Stn. 1, 2, and 3), high in open waters of the Southern Antarctic Circumpolar Current Front (SACCF) in the central Scotia Sea (Stn. 5), and moderate further north (Stn. 6 and 7). Krill had low lipid reserves (˜6.5% of dry mass, DM), low mass:length ratios (˜1.7 mg DM mm -1), and small digestive glands (˜7% of total DM) near the ice edge. The stomachs contained lithogenic particles, diatom debris, and bacterial fatty acids, but low proportions of diatom-indicating fatty acids, which suggest that these krill were feeding on detritus rather than on fresh ice algae. In the SACCF, krill had higher lipid reserves (˜10% of DM), high mass:length ratios (˜2.2 mg DM mm -1), and large digestive glands (˜16% of total DM). Stomach content and tissue composition indicate feeding on diatoms. In the north, moderate food concentrations co-occurred with low lipid reserves in krill, and moderate mass:length ratios and digestive gland sizes. Only in the phytoplankton bloom in the SACCF had the mating season already started and some females were about to spawn. Based on the way krill processed their food at the different stations, we indicate two mechanisms that can lead to fast regeneration of body reserves and oocyte maturation in E. superba. One is "superfluous" feeding at high food concentrations, which maximises the overall nutrient gain

  8. Pigment characterization for the 2011 bloom in Qinhuangdao implicated "brown tide" events in China

    Institute of Scientific and Technical Information of China (English)

    KONG Fanzhou; YU Rencheng; ZHANG Qingchun; YAN Tian; ZHOU Mingjiang

    2012-01-01

    A large-scale bloom occurred from May to June in 2011 in sea area near Qinhuangdao of the Bohai Sea,leading to huge damage of the scallop culture industry.Similar blooms have been observed in this region for three years.The causative species of the bloom,which dominated the phytoplankton community with the maximum cell density around 109 cell/L,could not be identified with morphological features due to the small cell size (~2 μm).A pigment analytical method was then adopted to analyze the pigment profile of the phytoplankton samples collected from the blooming sea area.It was found that pico-sized (<2 μm),nano-sized (2-20 μm),and bulk phytoplankton samples had similar pigment profile,representing the pigment signature of the bloom-causative species.The major pigments detected included 19-butanoyloxyfucoxanthin (But-fuco),fucoxanthin (Fuco),diadinoxanthin (Diad) and chlorophyll a (Chl a),and high content of But-fuco was the most significant characteristics of the phytoplankton samples.Based on the pigment composition and content,the bloom-causative species could be tentatively identified as pelagophyte,"type 8" group of haptophyte,or silicoflagellate.Some unique features of the bloom,such as the extremely high cell density,small-sized and But-fuco containing cells,occurring in early summer,and the feeding-cessation effects on scallops,suggest it be a "brown tide" event similar to those reported in the east coast of the United States of America.The recurrent "brown tide" events and their dramatic impacts on the shellfish mariculture industry in Qinhuangdao need close attention in the coming years.

  9. A niche model to predict Microcystis bloom decline in Chaohu Lake, China

    Institute of Scientific and Technical Information of China (English)

    WANG Zhicong; LI Zhongjie; LI Dunhai

    2012-01-01

    Cyanobacterial blooms occur frequently in lakes due to eutrophication.Although a number of models have been proposed to forecast algal blooms,a good and applicable method is still lacking.This study explored a simple and effective mathematical-ecological model to evaluate the growth status and predict the population dynamics of Microcystis blooms.In this study,phytoplankton were collected and identified from 8 sampling sites in Chaohu Lake every month from July to October,2010.The niche breadth and niche overlap of common species were calculated using standard equations,and the potential relative growth rates of Microcystis were calculated as a weighted-value of niche overlap.In July,the potential relative growth rate was 2.79 (a.u.,arbitrary units) but then rapidly declined in the following months to -3.99 a.u.in September.A significant correlation (R=0.998,P<0.01) was found in the model between the net-increase in biomass of Microcystis in the field and the predicted values calculated by the niche model,we concluded that the niche model is suitable for forecasting the dynamics of Microcystis blooms.Redundancy analysis indicated that decreases in water temperature,dissolved oxygen and total dissolved phosphorus might be major factors underlying bloom decline.Based on the theory of community succession being caused by resource competition,the growth and decline of blooms can be predicted from a community structure.This may provide a basis for early warning and control of algal blooms.

  10. A comprehensive insight into functional profiles of free-living microbial community responses to a toxic Akashiwo sanguinea bloom

    Science.gov (United States)

    Yang, Caiyun; Li, Yi; Zhou, Yanyan; Lei, Xueqian; Zheng, Wei; Tian, Yun; van Nostrand, Joy D.; He, Zhili; Wu, Liyou; Zhou, Jizhong; Zheng, Tianling

    2016-10-01

    Phytoplankton blooms are a worldwide problem and can greatly affect ecological processes in aquatic systems, but its impacts on the functional potential of microbial communities are limited. In this study, a high-throughput microarray-based technology (GeoChip) was used to profile the functional potential of free-living microbes from the Xiamen Sea Area in response to a 2011 Akashiwo sanguinea bloom. The bloom altered the overall community functional structure. Genes that were significantly (p information on the relationship of algae to other microbes in aquatic systems, and provides new insights into our understanding of ecological impacts of phytoplankton blooms.

  11. 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.

  12. Coastal eutrophication, land use changes and Ceratium furca (Dinophyceae) blooms in Pago Pago Harbor, American Samoa 2007-2009

    Science.gov (United States)

    Morton, Steve L.; Shuler, Andrew; Paternoster, Jeff; Fanolua, Sharon; Vargo, Don

    2011-07-01

    The bloom forming dinoflagellate, Ceratium furca, has been linked with coastal eutrophication worldwide in tropical and subtropical locations. During the summer of 2007, an unusual 6-month long bloom of C. furca was observed in Pago Pago Harbor, Tutuila Island, American Samoa. Incidents of dinoflagellate blooms in this area have not been previously reported. The bloom was first reported in May and dissipated in November 2007. In February-March 2009, a similar C. furca bloom was observed. During both blooms, no fish mortality events were reported. Maximum cell counts were observed on September 20, 2007 at 9 200 cell/mL. At this time, total nitrogen was measured at 1.2 mg/L while total phosphate was below detection limits. Changes in land use practices may have been the primary driver of these blooms. Intense fertilization of athletic fields coupled with ineffective management strategies is hypothesized to have a direct link to the increase in nutrients found in the Pago Pago Harbor and may have been the trigger for the initialization of these blooms. During 2008, the fields were not used due to an infestation of the fire ant, Solenopsis geminata. Once controlled, the fields were opened again in 2009 and fertilizers were applied in January, a month before the bloom was observed.

  13. Research on Z Source Inverter Grid-connected System Based on Repetitive Control and Fuzzy PI Control%基于重复控制和模糊PI控制的Z源逆变器并网研究∗

    Institute of Scientific and Technical Information of China (English)

    杨旭红; 王毅舟; 王创典; 何超杰

    2016-01-01

    Z source inverter has been wildly used because of its powerful boost and buck capability. The traditional control strategy often uses the double loop PI control of outer voltage loop and inner current loop. It was hard to achieve higher control accuracy while using the control of traditional double PI loop and the harmonic distortion rate of grid-connected current was high. The periodic harmonic interference could be better restrained with the repetitive control and the controls parameter could be adjusted online by fuzzy control according to characteristic of nonlinear system. As a result, a new control strategy based on repetitive control and fuzzy PI control was proposed. The harmonic interference could be better restrained by the strategy and the control accuracy was higher. Compared with the traditional method, the effectiveness and validity of the proposed method were verified through the simulation experiment.%Z源逆变器由于其强大的升/降压能力而得到广泛应用,传统的控制策略通常采用电压外环和电流内环构成的双环PI控制。但传统的双环PI控制无法达到较高的控制精度且并网电流谐波畸变率较高。重复控制具有抑制周期性谐波干扰的优点,而模糊控制可根据非线性系统特点在线调整控制参数,于是提出了一种基于重复控制和模糊PI控制相结合的新型控制策略,可较好地抑制谐波干扰,并具有较高的控制精度。通过仿真研究,与传统的方法比较,证明所提方法的有效性和正确性。

  14. Inhibition effect of engineered silver nanoparticles to bloom forming cyanobacteria

    Science.gov (United States)

    Thuy Duong, Thi; Son Le, Thanh; Thu Huong Tran, Thi; Kien Nguyen, Trung; Ho, Cuong Tu; Hien Dao, Trong; Phuong Quynh Le, Thi; Chau Nguyen, Hoai; Dang, Dinh Kim; Thu Huong Le, Thi; Thu Ha, Phuong

    2016-09-01

    Silver nanoparticle (AgNP) has a wide range antibacterial effect and is extensively used in different aspects of medicine, food storage, household products, disinfectants, biomonitoring and environmental remediation etc. In the present study, we examined the growth inhibition effect of engineered silver nanoparticles against bloom forming cyanobacterial M. aeruginosa strain. AgNPs were synthesized by a chemical reduction method at room temperature and UV-Vis spectroscopy, scanning electron microscopy (SEM), transmission electron microscope (TEM) showed that they presented a maximum absorption at 410 nm and size range between 10 and 18 nm. M. aeruginosa cells exposed during 10 d to AgNPs to a range of concentrations from 0 to 1 mg l-1. The changes in cell density and morphology were used to measure the responses of the M. aeruginosa to AgNPs. The control and treatment units had a significant difference in terms of cell density and growth inhibition (p < 0.05). Increasing the concentration of AgNPs, a reduction of the cell growths in all treatment was observed. The inhibition efficiency was reached 98.7% at higher concentration of AgNPs nanoparticles. The term half maximal effective concentration (EC50) based on the cell growth measured by absorbance at 680 nm (A680) was 0.0075 mg l-1. The inhibition efficiency was 98.7% at high concentration of AgNPs (1 mg l-1). Image of SEM and TEM reflected a shrunk and damaged cell wall indicating toxicity of silver nanoparticles toward M. aeruginosa.

  15. Effect of Alexandrium tamarense on three bloom-forming algae

    Science.gov (United States)

    Yin, Juan; Xie, Jin; Yang, Weidong; Li, Hongye; Liu, Jiesheng

    2010-07-01

    We investigated the allelopathic properties of Alexandrium tamarense (Laboar) Balech on the growth of Prorocentrum donghaiense Lu, Chattonella marina (Subrahmanyan) Hara et Chihara and Heterosigma akashiwo (Hada) Hada in a laboratory experiment. We examined the growth of A. tamarense, C. marina, P. donghaiense and H. Akashiwo in co-cultures and the effect of filtrates from A. tamarense cultures in various growth phases, on the three harmful algal bloom (HAB)-forming algae. In co-cultures with A. tamarense, both C. marina and H. akashiwo were dramatically suppressed at high cell densities; in contrast, the growth of P. donghaiense varied in different inoculative ratios of A. tamarense and P. donghaiense. When the ratio was 1:1 ( P. donghaiense: A. tamarense), growth of P. donghaiense was inhibited considerably, while the growth of P. donghaiense was almost the same as that of the control when the ratio was 9:1. The growth difference of P. donghaiense, C. marina and H. akashiwo when co-cultured with A. tamarense indicated that the allelopathic effect may be one of the important factors in algal competition and phytoplankton succession involving A. tamarense. In addition, the filtrate from A. tamarense culture had negative impacts on these three HAB algae, and such inhibition varied with different growth phases of A. tamarense in parallel with reported values of PSP toxin content in Alexandrium cells. This implied that PSP toxin was possibly involved in allelopathy of A. tamarense. However, the rapid decomposition and inactivation of PSP toxin above pH 7 weakened this possibility. Further studies on the allelochemicals responsible for the allelopathy of A. tamarense need to be carried out in future.

  16. Selective algicidal action of peptides against harmful algal bloom species.

    Directory of Open Access Journals (Sweden)

    Seong-Cheol Park

    Full Text Available Recently, harmful algal bloom (HAB, also termed "red tide", has been recognized as a serious problem in marine environments according to climate changes worldwide. Many novel materials or methods to prevent HAB have not yet been employed except for clay dispersion, in which can the resulting sedimentation on the seafloor can also cause alteration in marine ecology or secondary environmental pollution. In the current study, we investigated that antimicrobial peptide have a potential in controlling HAB without cytotoxicity to harmless marine organisms. Here, antimicrobial peptides are proposed as new algicidal compounds in combating HAB cells. HPA3 and HPA3NT3 peptides which exert potent antimicrobial activity via pore forming action in plasma membrane showed that HPA3NT3 reduced the motility of algal cells, disrupted their plasma membrane, and induced the efflux of intracellular components. Against raphidoflagellate such as Heterosigma akashiwo, Chattonella sp., and C. marina, it displayed a rapid lysing action in cell membranes at 1~4 µM within 2 min. Comparatively, its lysing effects occurred at 8 µM within 1 h in dinoflagellate such as Cochlodium polykrikoides, Prorocentrum micans, and P. minimum. Moreover, its lysing action induced the lysis of chloroplasts and loss of chlorophyll a. In the contrary, this peptide was not effective against Skeletonema costatum, harmless algal cell, even at 256 µM, moreover, it killed only H. akashiwo or C. marina in co-cultivation with S. costatum, indicating to its selective algicidal activity between harmful and harmless algal cells. The peptide was non-hemolytic against red blood cells of Sebastes schlegeli, the black rockfish, at 120 µM. HAB cells were quickly and selectively lysed following treatment of antimicrobial peptides without cytotoxicity to harmless marine organisms. Thus, the antibiotic peptides examined in our study appear to have much potential in effectively controlling HAB with minimal

  17. Digital Image Analysis of Flowering in the Repeat-Blooming Creosotebush (Larrea tridentata) in Relation to Climatic Factors

    Science.gov (United States)

    Benton, L. M.; Kurc, S. A.

    2008-12-01

    Recent studies have shown that phenology (seasonal timing of life cycle events) is an effective integrator of the impacts of climate change on natural systems. Thus, understanding the climate signals that activate plant phenological responses (e.g., flowering and leaf production) will allow for improved modeling efforts and more effective ecosystem management strategies to mitigate the effects of climate change. With warmer and drier weather patterns predicted for the Desert Southwest in the coming century it can be expected that plant phenological patterns will be altered as a result. The most dominant and widespread shrub species of the warm desert ecosystems of North America is the creosotebush (Larrea tridentata). Consequently, creosotebush has a major impact on the structure, functioning, and flow of resources (i.e., carbon, water, and energy) in these regions, and when in bloom serves as an abundant and reliable food source for hundreds of pollinating insects that synchronize their emergence with flowering time. In this study, we hypothesize that frequency, duration and abundance of flowers in the repeat-blooming creosotebush are regulated by (1) temperature during the spring and (2) soil moisture below the depth of atmospheric demand in the summer. We make use of daily digital images from three stations at the Santa Rita Experimental Range in southern Arizona. These stations are located within the footprint of an eddy covariance tower, where continuous records of precipitation, air temperature, soil temperature, soil moisture at various depths, and net radiation are also being collected. Unlike more discrete methods used to observe seasonal changes in vegetation, use of daily images results in a continuous record that can be directly compared to micrometeorological data, allowing us to evaluate the bloom-up response of creosotebush alongside (1) air temperature, (2) soil temperature, and (3) soil water content fluctuations across time. We show that this

  18. The Subpolar North Atlantic Spring Bloom - What Did We Learn from the NAB 2008 Autonomous Experiment?

    Science.gov (United States)

    Perry, M. J.

    2015-12-01

    The subpolar North Atlantic bloom is one of the most remarkable features on the planet, with almost explosive 'greening' of the oceans. Over decades, investigators from countries bordering the North Atlantic have caught snippets of the bloom from research vessels or merchant ships transiting between continents. On 4 April 2008, Eric D'Asaro, Craig Lee, and I began a comprehensive study of the initiation and demise of the spring bloom using 2 types of autonomous platforms - a patch-following Lagrangian mixed-layer float and 4 float-following gliders. The 3 mo autonomous experiment integrated measurements from the float, gliders and ships, observations from satellites, and analyses from models. The diatom-dominated bloom began in mid April when the water column stabilized, not by solar warming, but rather by eddy-driven slumping of horizontal density gradients. The resulting bloom was patchy in both biomass and phytoplankton diversity, despite high, non-limiting concentrations of macronutrients. Magnitudes and relative proportions of net community productivity (NCP; determined from autonomous budgets of O2 and NO3) and net phytoplankton productivity (NPP; computed from ship-based photosynthetic parameters and float-based biomass and light) diverged as the bloom evolved, with higher fractions of particulate organic carbon (POC) consumed within the mixed layer as the bloom aged. Export productivity (EP; derived as the difference between NCP and accumulation rate of POC) was of similar magnitude during the May diatom bloom and the June picophytoplankton bloom. When silicic acid dropped to 1 μM, diatoms aggregated and sank; the deep flux event was dominated by resting spores of Chaetoceros. Although a short-lived event, it was ubiquitously observed by the 4 gliders and ship. An eddy-driven subduction event was likewise observed, indicating transport of otherwise non-sinking POC along isopycnals to depths of > 200 m. These striking export events reinforce the value of a

  19. Effects of Lyngbya majuscula blooms on the seagrass Halodule wrightii and resident invertebrates.

    Science.gov (United States)

    Tiling, Kathryn; Proffitt, C Edward

    2017-02-01

    Cyanobacterial blooms have been increasing worldwide due to increased nutrients associated with urban, industrial, and agricultural development. Blooms that occur in the Indian River Lagoon (IRL), Florida may be increased by nutrient-laden runoff from storm water and non-point sewage pollution due to alterations to the watershed. In the IRL, during the summer of 2006, extensive blooms of the marine cyanobacterium, Lyngbya majuscula, were observed forming mats throughout beds of the seagrass Halodule wrightii in Fort Pierce, Florida. The effects of cyanobacterial blooms were compared to artificial shading of H. wrightii to assess the shading potential of L. majuscula. The combined effects of L. majuscula removal and artificial shading showed increases in the below ground biomass of H. wrightii. However, leaf length increased in the presence of L. majuscula. In response to artificial shading, H. wrightii decreased in density, but showed similar leaf elongation. A common bivalve in our study area, Macoma constricta, increased in density when L. majuscula was removed. Therefore, when L. majuscula blooms occur, light limitation is one of the mechanisms altering H. wrightii density and leaf lengths in the IRL. Loss of H. wrightii biomass due to shading from cyanobacterial mats may further damage the diversity and habitat value of the IRL.

  20. DMS gas transfer coefficients from algal blooms in the Southern Ocean

    Directory of Open Access Journals (Sweden)

    T. G. Bell

    2014-11-01

    Full Text Available Air/sea dimethylsulfide (DMS fluxes and bulk air/sea gradients were measured over the Southern Ocean in February/March 2012 during the Surface Ocean Aerosol Production (SOAP study. The cruise encountered three distinct phytoplankton bloom regions, consisting of two blooms with moderate DMS levels, and a high biomass, dinoflagellate-dominated bloom with high seawater DMS levels (>15 nM. Gas transfer coefficients were considerably scattered at wind speeds above 5 m s−1. Bin averaging the data resulted in a linear relationship between wind speed and mean gas transfer velocity consistent with that previously observed. However, the wind speed-binned gas transfer data distribution at all wind speeds is positively skewed. The flux and seawater DMS distributions were also positively skewed, which suggests that eddy covariance-derived gas transfer velocities are consistently influenced by additional, log-normal noise. A~flux footprint analysis was conducted during a transect into the prevailing wind and through elevated DMS levels in the dinoflagellate bloom. Accounting for the temporal/spatial separation between flux and seawater concentration significantly reduces the scatter in computed transfer velocity. The SOAP gas transfer velocity data shows no obvious modification of the gas transfer-wind speed relationship by biological activity or waves. This study highlights the challenges associated with eddy covariance gas transfer measurements in biologically active and heterogeneous bloom environments.

  1. Phytoplankton blooms on the western shelf of Tasmania: evidence of a highly productive ecosystem

    Science.gov (United States)

    Kämpf, J.

    2015-01-01

    Satellite-derived chlorophyll a data using the standard NASA-OC3 (ocean colour) algorithm are strongly biased by coloured dissolved organic matter and suspended sediment of river discharges, which is a particular problem for the western Tasmanian shelf. This work reconstructs phytoplankton blooms in the study region using a quadratic regression between OC3 data and chlorophyll fluorescence based on the fluorescence line height (FLH) data. This regression is derived from satellite data of the nearby Bonney upwelling region, which is devoid of river influences. To this end, analyses of 10 years of MODIS-aqua satellite data reveal the existence of a highly productive ecosystem on the western Tasmanian shelf. The region normally experiences two phytoplankton blooms per annum. The first bloom occurs during late austral summer months as a consequence of upwelling-favourable coastal winds. Hence, the western Tasmanian shelf forms a previously unknown upwelling centre of the regional upwelling system, known as Great South Australian Coastal Upwelling System. The second phytoplankton bloom is a classical spring bloom also developing in the adjacent Tasman Sea. The author postulates that this region forms another important biological hot spot for the regional marine ecosystem.

  2. 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.

  3. Responses of phyto- and zooplankton communities to Prymnesium polylepis (Prymnesiales bloom in the Baltic Sea.

    Directory of Open Access Journals (Sweden)

    Elena Gorokhova

    Full Text Available A large bloom of Prymnesium polylepis occurred in the Baltic Sea during the winter 2007-spring 2008. Based on numerous reports of strong allelopathic effects on phytoplankton exerted by P. polylepis and its toxicity to grazers, we hypothesized that during this period negative correlations will be observed between P. polylepis and (1 main phytoplankton groups contributing to the spring bloom (i.e., diatoms and dinoflagellates, and (2 zooplankton growth and abundance. To test these hypotheses, we analyzed inter-annual variability in phytoplankton and zooplankton dynamics as well as growth indices (RNA:DNA ratio in dominant zooplankton in relation to the Prymnesium abundance and biomass. Contrary to the hypothesized relationships, no measurable negative responses to P. polylepis were observed for either the total phytoplankton stocks or the zooplankton community. The only negative response, possibly associated with P. polylepis occurrence, was significantly lower abundance of dinoflagellates both during and after the bloom in 2008. Moreover, contrary to the expected negative effects, there were significantly higher total phytoplankton abundance as well as significantly higher winter abundance and winter-spring RNA:DNA ratio in dominant zooplankton species in 2008, indicating that P. polylepis bloom coincided with favourable feeding conditions for zooplankton. Thus, primary consumers, and consequently also zooplanktivores (e.g., larval fish and mysids, may benefit from haptophyte blooms, particularly in winter, when phytoplankton is scarce.

  4. Effects of an Arctic under-ice bloom on solar radiant heating of the water column

    Science.gov (United States)

    Taskjelle, Torbjørn; Granskog, Mats A.; Pavlov, Alexey K.; Hudson, Stephen R.; Hamre, Børge

    2017-01-01

    The deposition of solar energy in the upper Arctic Ocean depends, among other things, on the composition of the water column. During the N-ICE2015 expedition, a drift in the Arctic pack ice north of Svalbard, an under-ice phytoplankton bloom was encountered in May 2015. This bloom led to significant changes in the inherent optical properties (IOPs) of the upper ocean. Mean values of total water absorption in the upper 20 m of the water column were up to 4 times higher during the bloom than prior to it. The total water attenuation coefficient increased by a factor of up to around 7. Radiative transfer modeling, with measured IOPs as input, has been performed with a coupled atmosphere-ice-ocean model. Simulations are used to investigate the change in depth-dependent solar heating of the ocean after the onset of the bloom, for wavelengths in the region 350-700 nm. Effects of clouds, sea ice cover, solar zenith angle, as well as the average cosine for scattering of the ocean inclusions are evaluated. An increase in energy absorption in the upper 10 m of about 36% is found under 25 cm ice with 2 cm snow, for bloom conditions relative to prebloom conditions, which may have implications for ice melt and growth in spring. Thicker clouds and lower sun reduce the irradiance available, but lead to an increase in relative absorption.

  5. A Recent Survey on Bloom Filters in Network Intrusion Detection Systems

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    K.Saravanan,

    2011-03-01

    Full Text Available Computer networks are prone to hacking, viruses and other malware; a Network Intrusion Detection System (NIDS is needed to protect the end-user machines from threats. An effective NIDS is therefore anetwork security system capable of protecting the end user machines well before a threat or intruder affects. NIDS requires a space efficient data base for detection of threats in high speed conditions. A bloom filter is a space efficient randomized data structure for representing a set in order to support membership queries. These Bloom filters allow false positive results (FPR but the space saving capability often outweigh this drawback provided the probability of FPR is controlled. Research is being done to reduce FPR by modifying the structure of bloom filters and enabling it to operate in the increasing network speeds, thus variant bloom filters are being introduced. The aim of this paper is to survey the ways in which Bloom filters have been used and modified to be used in high speed Network Intrusion Detection Systems with their merits and demerits.

  6. Seasonal morphological variability in an in situ Cyanobacteria monoculture: example from a persistent Cylindrospermopsis bloom in Lake Catemaco, Veracruz, Mexico

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    Owen Lind

    2016-03-01

    Full Text Available The phrase cyanobacteria bloom implies a transient condition in which one to few species dominates communities. In this paper we describe a condition in which the bloom is of multi-year duration consisting of different morphologies of a single cyanobacteria species. Lake Catemaco, Veracruz, México maintained a year-round massive (108 trichomes L-1 population of potentially toxin-producing cyanobacteria, Cylindrospermopsis spp. The trichomes are present as straight and coiled morphotypes.  The relative trichome morphology abundance varied with rainy (June – October and dry seasons (November – May, but total trichome abundance did not vary.  Coiled trichomes and heterocytes (occurring only on coiled trichomes were significantly more abundant, both absolutely and relatively, during the dry season. Both coiled trichome and heterocyte mean volumes were significantly smaller during the rainy season than during the dry season.  Biovolumes were largest in January when water temperature was 5º C cooler suggesting buoyancy as a morphology-determining factor. However, with a more than three-fold lower TIN concentration during the dry season, we hypothesized that the coiled morphotype became abundant primarily because it formed heterocytes, which the straight morphotype did not. Spatial trichome and heterocyte abundance differences were small among the 15 lake sites (average CV for all dates = 20%. However, there was a pattern of increased heterocyte and coiled trichome abundance from lake inflow, as a nitrogen source, to outflow during the rainy season. The total volume of heterocytes per litre of lake water increased progressively four-fold from a minimum early in the rainy season to a maximum at the end of the dry season. Morphological diversity, as seen in Lake Catemaco, can partially compensate for the lack of species diversity in determination of community structure.

  7. Resting state functional connectivity in perfusion imaging: correlation maps with BOLD connectivity and resting state perfusion.

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    Roberto Viviani

    Full Text Available Functional connectivity is a property of the resting state that may provide biomarkers of brain function and individual differences. Classically, connectivity is estimated as the temporal correlation of spontaneous fluctuations of BOLD signal. We investigated differences in connectivity estimated from the BOLD and CBF signal present in volumes acquired with arterial spin labeling technique in a large sample (N = 265 of healthy individuals. Positive connectivity was observable in both BOLD and CBF signal, and was present in the CBF signal also at frequencies lower than 0.009 Hz, here investigated for the first time. Negative connectivity was more variable. The validity of positive connectivity was confirmed by the existence of correlation across individuals in its intensity estimated from the BOLD and CBF signal. In contrast, there was little or no correlation across individuals between intensity of connectivity and mean perfusion levels, suggesting that these two biomarkers correspond to distinct sources of individual differences.

  8. Asymptotically hyperbolic connections

    CERN Document Server

    Fine, Joel; Krasnov, Kirill; Scarinci, Carlos

    2015-01-01

    General Relativity in 4 dimensions can be equivalently described as a dynamical theory of SO(3)-connections rather than metrics. We introduce the notion of asymptotically hyperbolic connections, and work out an analog of the Fefferman-Graham expansion in the language of connections. As in the metric setup, one can solve the arising "evolution" equations order by order in the expansion in powers of the radial coordinate. The solution in the connection setting is arguably simpler, and very straightforward algebraic manipulations allow one to see how the obstruction appears at third order in the expansion. Another interesting feature of the connection formulation is that the "counter terms" required in the computation of the renormalised volume all combine into the Chern-Simons functional of the restriction of the connection to the boundary. As the Chern-Simons invariant is only defined modulo large gauge transformations, the requirement that the path integral over asymptotically hyperbolic connections is well-d...

  9. Military ration chocolate: the effect of simulated tropical storage on sensory quality, structure and bloom formation.

    Science.gov (United States)

    Bui, Lan T T; Coad, Ross

    2014-10-01

    A storage trial was conducted to observe the effect of typical northern Australia climatic conditions on a military ration chocolate (RC). The results indicate that sensory quality decreased during storage; after seven days the chocolate was no longer of acceptable appearance. Deterioration in RC sensory quality was strongly correlated with decreases in visual acceptance (appearance) and increases in degree of blooming. Instrumental colour measurements were also strongly correlated with sensory ratings. Visual and microscopic observations provide evidence for movement of fat to and across the surface of the RC, behaviour that may be explained in terms of the phase transition theory of fat blooming. DSC thermographs provide evidence of a shift from predominantly polymorph form V in a fresh RC sample to a greater proportion of form VI in bloomed storage samples. The study provides a baseline against which efforts to improve the quality of RC may be evaluated.

  10. Thermo-Mechanical Behavior of the Continuous Casting Bloom in the Heavy Reduction Process

    Science.gov (United States)

    Ji, Cheng; Wu, Chen-hui; Zhu, Miao-yong

    2016-08-01

    A two-stage sequential heavy reduction (HR) method, in which the reduction amount was increased both before and after the solidification end, is presented to simultaneously improve the homogeneity and compactness of the continuous casting bloom. With bearing steel GCr15 chosen as the specific research steel, a three-dimensional thermal-mechanical finite element model was developed to simulate and analyze the thermal and mechanical behaviors of the continuous casting bloom during the HR process. In order to ensure the accuracy of the simulation, the constitutive model parameters were derived from the experimental results. The predicted temperature distribution and shell thickness were verified using a thermal infrared camera and nail shooting results, respectively. The real measured relationship between the HR pressure and amount were applied to verify the mechanical model. The explorative application results showed that the quality of the bloom center and compactness of rolled bars have both been significantly improved after the HR was applied.

  11. An unprecedented coastwide toxic algal bloom linked to anomalous ocean conditions

    Science.gov (United States)

    McCabe, Ryan M.; Hickey, Barbara M.; Kudela, Raphael M.; Lefebvre, Kathi A.; Adams, Nicolaus G.; Bill, Brian D.; Gulland, Frances M. D.; Thomson, Richard E.; Cochlan, William P.; Trainer, Vera L.

    2016-10-01

    A coastwide bloom of the toxigenic diatom Pseudo-nitzschia in spring 2015 resulted in the largest recorded outbreak of the neurotoxin, domoic acid, along the North American west coast. Elevated toxins were measured in numerous stranded marine mammals and resulted in geographically extensive and prolonged closures of razor clam, rock crab, and Dungeness crab fisheries. We demonstrate that this outbreak was initiated by anomalously warm ocean conditions. Pseudo-nitzschia australis thrived north of its typical range in the warm, nutrient-poor water that spanned the northeast Pacific in early 2015. The seasonal transition to upwelling provided the nutrients necessary for a large-scale bloom; a series of spring storms delivered the bloom to the coast. Laboratory and field experiments confirming maximum growth rates with elevated temperatures and enhanced toxin production with nutrient enrichment, together with a retrospective analysis of toxic events, demonstrate the potential for similarly devastating ecological and economic disruptions in the future.

  12. An unprecedented coastwide toxic algal bloom linked to anomalous ocean conditions

    Science.gov (United States)

    Hickey, Barbara M.; Kudela, Raphael M.; Lefebvre, Kathi A.; Adams, Nicolaus G.; Bill, Brian D.; Gulland, Frances M. D.; Thomson, Richard E.; Cochlan, William P.; Trainer, Vera L.

    2016-01-01

    Abstract A coastwide bloom of the toxigenic diatom Pseudo‐nitzschia in spring 2015 resulted in the largest recorded outbreak of the neurotoxin, domoic acid, along the North American west coast. Elevated toxins were measured in numerous stranded marine mammals and resulted in geographically extensive and prolonged closures of razor clam, rock crab, and Dungeness crab fisheries. We demonstrate that this outbreak was initiated by anomalously warm ocean conditions. Pseudo‐nitzschia australis thrived north of its typical range in the warm, nutrient‐poor water that spanned the northeast Pacific in early 2015. The seasonal transition to upwelling provided the nutrients necessary for a large‐scale bloom; a series of spring storms delivered the bloom to the coast. Laboratory and field experiments confirming maximum growth rates with elevated temperatures and enhanced toxin production with nutrient enrichment, together with a retrospective analysis of toxic events, demonstrate the potential for similarly devastating ecological and economic disruptions in the future. PMID:27917011

  13. Finite Element Analysis of 3-D Electromagnetic Field in Bloom Continuous Casting Mold

    Institute of Scientific and Technical Information of China (English)

    LIU Xu-dong; YANG Xiao-dong; ZHU Miao-yong; CHEN Yong; YANG Su-bo

    2007-01-01

    Three-dimensional finite element model of electromagnetic stirrer was built to predict magnetic field in a bloom continuous casting mold for steel during operation. The effects of current intensity, current frequency, and mold copper plate thickness on the magnetic field distribution in the mold were investigated. The results show that the magnetic induction intensity increases linearly with the increase in current intensity and decreases with the increase in current frequency. Increasing current intensity and frequency is available in increasing the electromagnetic force. The Joule heat decreases gradually from surface to center of bloom, and a maximum Joule heat can be found on corner of bloom. The prediction of magnetic induction intensity is in good agreement with the measured values.

  14. Dynamic Cognitive Process Application of Blooms Taxonomy for Complex Software Design in the Cognitive Domain

    CERN Document Server

    Kumar, NR Shashi; Selvarani, R

    2010-01-01

    Software design in Software Engineering is a critical and dynamic cognitive process. Accurate and flawless system design will lead to fast coding and early completion of a software project. Blooms taxonomy classifies cognitive domain into six dynamic levels such as Knowledge at base level to Comprehension, Application, Analysis, Synthesis and Evaluation at the highest level in the order of increasing complexity. A case study indicated in this paper is a gira system, which is a gprs based Intranet Remote Administration which monitors and controls the intranet from a mobile device. This paper investigates from this case study that the System Design stage in Software Engineering uses all the six levels of Blooms Taxonomy. The application of the highest levels of Blooms Taxonomy such as Synthesis and Evaluation in the design of gira indicates that Software Design in Software Development Life Cycle is a complex and critical cognitive process.

  15. 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.

  16. Tight Coupling of Glaciecola spp. and Diatoms during Cold-Water Phytoplankton Spring Blooms

    Science.gov (United States)

    von Scheibner, Markus; Sommer, Ulrich; Jürgens, Klaus

    2017-01-01

    Early spring phytoplankton blooms can occur at very low water temperatures but they are often decoupled from bacterial growth, which is assumed to be often temperature controlled. In a previous mesocosm study with Baltic Sea plankton communities, an early diatom bloom was associated with a high relative abundance of Glaciecola sequences (Gammaproteobacteria), at both low (2°C) and elevated (8°C) temperatures, suggesting an important role for this genus in phytoplankton-bacteria coupling. In this study, the temperature-dependent dynamics of free-living Glaciecola spp. during the bloom were analyzed by catalyzed reporter deposition fluorescence in situ hybridization using a newly developed probe. The analysis revealed the appearance of Glaciecola spp. in this and in previous spring mesocosm experiments as the dominating bacterial clade during diatom blooms, with a close coupling between the population dynamics of Glaciecola and phytoplankton development. Although elevated temperature resulted in a higher abundance and a higher net growth rate of Glaciecola spp. (Q10 ∼ 2.2), their growth was, in contrast to that of the bulk bacterial assemblages, not suppressed at 2°C and showed a similar pattern at 8°C. Independent of temperature, the highest abundance of Glaciecola spp. (24.0 ± 10.0% of total cell number) occurred during the peak of the phytoplankton bloom. Together with the slightly larger cell size of Glaciecola, this resulted in a ∼30% contribution of Glaciecola to total bacterial biomass. Overall, the results of this and previous studies suggest that Glaciecola has an ecological niche during early diatom blooms at low temperatures, when it becomes a dominant consumer of phytoplankton-derived dissolved organic matter.

  17. Blooms of cyanobacteria in a temperate Australian lagoon system post and prior to European settlement

    Science.gov (United States)

    Cook, Perran L. M.; Jennings, Miles; Holland, Daryl P.; Beardall, John; Briles, Christy; Zawadzki, Atun; Doan, Phuong; Mills, Keely; Gell, Peter

    2016-06-01

    Blooms of noxious N2 fixing cyanobacteria such as Nodularia spumigena are a recurring problem in some estuaries; however, the historic occurrence of such blooms in unclear in many cases. Here we report the results of a palaeoecological study on a temperate Australian lagoon system (the Gippsland Lakes) where we used stable isotopes and pigment biomarkers in dated cores as proxies for eutrophication and blooms of cyanobacteria. Pigment proxies show a clear signal, with an increase in cyanobacterial pigments (echinenone, canthaxanthin and zeaxanthin) in the period coinciding with recent blooms. Another excursion in these proxies was observed prior to the opening of an artificial entrance to the lakes in 1889, which markedly increased the salinity of the Gippsland Lakes. A coincident increase in the sediment organic-carbon content in the period prior to the opening of the artificial entrance suggests that the bottom waters of the lakes were more stratified and hypoxic, which would have led to an increase in the recycling of phosphorus. After the opening of the artificial entrance, there was a ˜ 60-year period with low values for the cyanobacterial proxies as well as a low sediment organic-carbon content suggesting a period of low bloom activity associated with the increased salinity of the lakes. During the 1940s, the current period of re-eutrophication commenced, as indicated by a steadily increasing sediment organic-carbon content and cyanobacterial pigments. We suggest that increasing nitrogen inputs from the catchment led to the return of hypoxia and increased phosphorus release from the sediment, which drove the re-emergence of cyanobacterial blooms.

  18. 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.

  19. Observations of phytoplankton spring bloom onset triggered by a density front in NW Mediterranean

    Directory of Open Access Journals (Sweden)

    A. Olita

    2013-09-01

    Full Text Available Phytoplankton bloom in NW Mediterranan sea is a seasonal event that mainly occurrs in a limited area (Gulf of Lyon and Provençal basin where this phenomenon is promoted by a cyclonic circulation, strong wind-driven mixing and subsequent spring restratification. At the southern boundary of this area a density front (North Balearic Front separating denser waters from the lighter Modified Atlantic Waters reservoir at south is suspected to trigger weaker and earlier (late winter blooms by (a enhanced pumping of nutrients into the euphotic layer and (b promoting an early restratification of the water column (by frontal instabilities. A multisensor glider round trip, equipped with CTD and fluorimeter, crossing the frontal area in February–March 2013, allowed to observe the bloom triggering after the decrease of intense wind-driven turbulent convection and mixing. Satellite imagery supports and confirms in-situ observations. It was shown that frontal activity has a relevant role in the promotion and acceleration of the dynamical restratification, with a consequent biological response in terms of primary production. Restratification is necessary preconditioning factor for bloom triggering in frontal area, net of other involved mechanism promoting the bloom as the enhanced biological pump. So, like for high-latitude fronts (Taylor and Ferrari, 2011a, also for this mid-latitude oligotrophic region front seems to promote new production by dynamically enahnced restratification inhibiting mixing. Finally, we argued that Sverdrup's Critical Depth criterion seems to apply in the northern well-mixed area, where the zeroing of heat fluxes (and related turbulent convection does not correspond to a prompt onset of the bloom (which appeared 1 month later.

  20. 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.

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

    Science.gov (United States)

    Klais, Riina; Tamminen, Timo; Kremp, Anke; Spilling, Kristian; Olli, Kalle

    2011-01-01

    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.

  2. 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.

  3. Formation of summer phytoplankton bloom in the northwestern Bay of Bengal in a coupled physical-ecosystem model

    Science.gov (United States)

    Thushara, V.; Vinayachandran, P. N.

    2016-12-01

    The Bay of Bengal (BoB) is considered to be a region of low biological productivity, owing to nutrient limitation, caused by strong salinity stratification induced by the freshwater influx from rivers and precipitation. Satellite and in situ observations, however, reveal the presence of prominent regional blooms in the bay in response to monsoonal forcings. Bloom dynamics of the BoB are presumably determined by freshwater as well as the local and remote effect of winds and remain to be explored in detail. Using a coupled physical-ecosystem model, we have examined the oceanic processes controlling productivity in the northwestern BoB during the summer monsoon. The region exhibits a prominent bloom lasting for a period of about 2 months, supporting major fishing zones along the northeast coast of India. The ecosystem model simulates the spatial and temporal evolution of the surface bloom in good agreement with Sea-Viewing Wide Field-of-View Sensor (SeaWiFS) observations. Vertical distribution of upper ocean physical and biological tracers and a nitrate budget analysis reveal the dominant role of coastal upwelling induced by alongshore winds in triggering the bloom. Horizontal advection plays a secondary role by supplying nutrients from coastal to offshore regions. The bloom decays with the weakening of winds and upwelling by the end of summer monsoon. The simulated bloom in the northwestern bay remains largely unaffected by the freshwater effects, since the peak bloom occurs before the arrival of river plumes.

  4. 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...

  5. Factors controlling the timing of the spring bloom in the Strait of Georgia estuary, British Columbia, Canada

    DEFF Research Database (Denmark)

    Yin, K.D.; Harrison, P.J.; Goldblatt, R.H.;

    1997-01-01

    , an El Nino year, the annual freshet of the Fraser River and probably the spring bloom started 1 month earlier. The bloom was interrupted by a wind event in late March. A few days later, its full recovery was interrupted by the peak in zooplankton grazing, and ambient ammonium concentrations increased...

  6. Promoting Cognitive Complexity in Graduate Written Work: Using Bloom's Taxonomy as a Pedagogical Tool To Improve Literature Reviews.

    Science.gov (United States)

    Granello, Darcy Haag

    2001-01-01

    Applies Bloom's "Taxonomy of Educational Objectives, Handbook I: Cognitive Domain" to the process of graduate-level writing in counselor education. Bloom's Taxonomy is provided as a mechanism to help students develop and demonstrate cognitive complexity when writing comprehensive literature reviews. Outlines tips to move students' writing to more…

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

    Science.gov (United States)

    Rosen, Barry H.; Ann St. Amand,

    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.

  8. Monitoring cyanobacteria-dominant algal blooms in eutrophicated Taihu Lake in China with synthetic aperture radar images

    Science.gov (United States)

    Wang, Ganlin; Li, Junsheng; Zhang, Bing; Shen, Qian; Zhang, Fangfang

    2015-01-01

    Monitoring algal blooms by optical remote sensing is limited by cloud cover. In this study, synthetic aperture radar (SAR) was deployed with the aim of monitoring cyanobacteria-dominant algal blooms in Taihu Lake in cloudy weather. The study shows that dark regions in the SAR images caused by cyanobacterial blooms damped the microwave backscatter of the lake surface and were consistent with the regions of algal blooms in quasi-synchronous optical images, confirming the applicability of SAR for detection of surface blooms. Low backscatter may also be associated with other factors such as low wind speeds, resulting in interference when monitoring algal blooms using SAR data alone. After feature extraction and selection, the dark regions were classified by the support vector machine method with an overall accuracy of 67.74%. SAR can provide a reference point for monitoring cyanobacterial blooms in the lake, particularly when weather is not suitable for optical remote sensing. Multi-polarization and multi-band SAR can be considered for use in the future to obtain more accurate information regarding algal blooms from SAR data.

  9. Promoting Cognitive Complexity in Graduate Written Work: Using Bloom's Taxonomy as a Pedagogical Tool To Improve Literature Reviews.

    Science.gov (United States)

    Granello, Darcy Haag

    2001-01-01

    Applies Bloom's "Taxonomy of Educational Objectives, Handbook I: Cognitive Domain" to the process of graduate-level writing in counselor education. Bloom's Taxonomy is provided as a mechanism to help students develop and demonstrate cognitive complexity when writing comprehensive literature reviews. Outlines tips to move students'…

  10. Integrative Indicator for Assessing the Alert Levels of Algal Bloom in Lakes: Lake Taihu as a Case Study

    Science.gov (United States)

    Li, Qinqin; Hu, Weiping; Zhai, Shuhua

    2016-01-01

    Algal blooms have recently become one of the most serious environmental problems in eutrophic freshwater ecosystems worldwide. Although many observation and simulation approaches have been applied to predict algal blooms, few studies have addressed the alert levels of algal blooms using integrative indicators in a large lake with multiple service function and significant horizontal heterogeneity. This study developed an integrative indicator assessment system (IIAS) to rank the alert level of algal blooms. In the IIAS, algal biomass, area percentage, distance from drinking water intake points, distance from scenic zones and duration of algal bloom were used as indicators to calculate a comprehensive alert level, which was classified into five grades (Vigilance, Low, Moderate, High, and Severe). Lake Taihu was taken as a case study to assess the comprehensive alert level of algal blooms in 2007 and 2010. The comprehensive alert level showed obvious spatial-temporal patterns, with an acceptable accuracy in Lake Taihu. The comprehensive alert levels were relatively higher in typical phytoplankton subzones than typical hydrophytes subzones and are more sensitive to weight factor in the northern and western subzones where high biomass usually occurs. Case study showed a very good application of the proposed comprehensive alert level assessment methodology, which can be adjusted to predict the degree of hazard of algal blooms in multi-service function large lakes to help the government and decision makers to act to prevent the disaster from algal bloom spreading.

  11. Basin-wide seasonal evolution of the Indian Ocean's phytoplankton blooms

    Digital Repository Service at National Institute of Oceanography (India)

    Levy, M.; Shankar, D.; Andre, J.M.; Shenoi, S.S.C.; Durand, F.; DeBoyer Montegut, C.

    that there was no significant increase of SCHL306 during winter, although SCHL concentrations in winter were not necessarily weak. The307 summer bloom also lasted longer than in the other regions of the Arabian Sea and what308 was actually observed in winter, during the period..., with some323 weak fluctuations (Figure 5l).324 Besides, the reconstruction of the seasonal cycles enabled the identification of significant325 lags in the onset of blooms in spatially adjacent regions (the onset times are identified by326 DRAFT July27...

  12. Reduction of blooming artifacts in cardiac CT images by blind deconvolution and anisotropic diffusion filtering

    Science.gov (United States)

    Castillo-Amor, Angélica M.; Navarro-Navia, Cristian A.; Cadena-Bonfanti, Alberto J.; Contreras-Ortiz, Sonia H.

    2015-12-01

    Even though CT is an imaging technique that offers high quality images, limitations on its spatial resolution cause blurring in small objects with high contrast. This phenomenon is known as blooming artifact and affects cardiac images with small calcifications and stents. This paper describes an approach to reduce the blooming artifact and improve resolution in cardiac images using blind deconvolution and anisotropic diffusion filtering. Deconvolution increases resolution but reduces signal-to-noise ratio, and the anisotropic diffusion filter counteracts this effect without affecting the edges in the image.

  13. [Spatial distribution pattern and stock estimation of nutrients during bloom season in Lake Taihu].

    Science.gov (United States)

    Jin, Ying-Wei; Zhu, Guang-Wei; Xu, Hai; Zhu, Meng-Yuan

    2015-03-01

    Based on the data of high density spatial sampling in July 2013, we analyzed the spatial distribution pattern of nutrients and estimated their amount during bloom season in Lake Taihu to discuss the correlation of algal bloom in different types of ecological water and nutrients in large shallow lake and the representative of its sampling sites. The research showed that nutrients and chlorophyll-a concentration (CHL) in Lake Taihu tended to reduce from northwest to southeast in general during bloom season. Nitrogen was mainly present in dissolved form, accounting for 76.28 percent of the total nitrogen (TN), and phosphorus was mainly present in particulate form, accounting for 66.38 percent of the total phosphorus (TP). The sampling points in the whole lake could be divided into four sections with significant difference between each other using principal component analysis and cluster analysis: The first section was located in the district of northwestern Lake Taihu, which represented the heavy eutrophic lake areas with serious blooms; the second section mainly included Meiliang Bay and area of river inflow into lake in South of Lake Taihu, which stood for moderate eutrophication of water quality; The third section included the central area and the southwest of lake, which represented the water area with medium water pollution, but blooms were frequent; And the fourth area was the remainder areas including Gonghu Bay, Xukou Bay, and Eastern Taihu, which stood for the region of weaker blooms and better water quality. Different factors also affected the growth of planktonic algae in different sections: From the point of the whole lake, CHL was significantly correlated with TP, TN, total dissolved nitrogen (TDN) and nitrate nitrogen (NO3(-) -N); while in the first section, CHL was significantly correlated to TP and TDN; CHL was correlated to TN and TDN in the second section; in the third section, the influencing factors were TP, reactive phosphate (PO4(3-) -P), TDN; PO

  14. 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.

  15. Massive outbreaks of Noctiluca scintillans blooms in the Arabian Sea due to spread of hypoxia.

    Digital Repository Service at National Institute of Oceanography (India)

    Gomes, H.R.; Goes, J.I.; Matondkar, S.G.P.; Buskey, E.J.; Basu, S.; Parab, S.G.; Thoppil, P.G.

    Research Laboratory, Stennis Space Center, Mississippi 39529, USA. Correspondence and requests for materials should be addressed to H.R.G. (email: helga@ldeo.columbia.edu). NATURE COMMUNICATIONS | 5:4862 | DOI: 10.1038/ncomms5862 | www.nature... beaker showing the density of the bloom. (d) Thick surface bloom of N. scintillans in the Arabian Sea on 17 February 2009. ARTICLE NATURE COMMUNICATIONS | DOI: 10.1038/ncomms5862 2 NATURE COMMUNICATIONS | 5:4862 | DOI: 10.1038/ncomms5862 | www.nature...

  16. Creating educational objectives for patient education using the new Bloom's Taxonomy.

    Science.gov (United States)

    Krau, Stephen D

    2011-09-01

    Whenever the nurse encounters a patient or a patient's family, there is a transfer of information that is expected to be incorporated into the patient's overall outcome. Objectives help guide the transfer of knowledge and provide a basis by which to evaluate the extent of the patient's understanding. Bloom's Taxonomy has been a cornerstone for the development of objectives in academe for over half of a century. The Revised Bloom's Taxonomy is a tool that can be used by nurses who educate patients to ensure the education session is focused, clear, has standards for evaluation, and is well documented.

  17. Aggregation and sedimentation processes during a spring phytoplankton bloom: A field experiment to test coagulation theory

    DEFF Research Database (Denmark)

    Kiørboe, Thomas; Lundsgaard, Claus; Olesen, Michael;

    1994-01-01

    Spring diatom blooms in temperate waters are often terminated by aggregation of the cells into large floes and subsequent mass sedimentation of the phytoplankton to the sea floor. The rate of aggregate formation by physical coagulation depends on the concentration of suspended particles, on the t......Spring diatom blooms in temperate waters are often terminated by aggregation of the cells into large floes and subsequent mass sedimentation of the phytoplankton to the sea floor. The rate of aggregate formation by physical coagulation depends on the concentration of suspended particles...

  18. An event-driven phytoplankton bloom in southern Lake Michigan observed by satellite.

    Energy Technology Data Exchange (ETDEWEB)

    Lesht, B. M.; Stroud, J. R.; McCormick, M. J.; Fahnenstiel, G. L.; Stein, M. L.; Welty, L. J.; Leshkevich, G. A.; Environmental Research; Univ. of Chicago; Great Lakes Research Lab.

    2002-04-15

    Sea-viewing Wide Field-of-View Sensor (SeaWiFS) images from June 1998 show a surprising early summer phytoplankton bloom in southern Lake Michigan that accounted for approximately 25% of the lake's annual gross offshore algal primary production. By combining the satellite imagery with in situ measurements of water temperature and wind velocity we show that the bloom was triggered by a brief wind event that was sufficient to cause substantial vertical mixing even though the lake was already stratified. We conclude that episodic events can have significant effects on the biological state of large lakes and should be included in biogeochemical process models.

  19. [Algal blooms at Banderas Bay, México (2000-2001), from SeaWiFS-sensor-data].

    Science.gov (United States)

    Gómez-Villarreal, María C; Martínez-Gaxiola, Marcos D; Peña-Manjarrez, José L

    2008-12-01

    Algal blooms for the period of 2000 and 2001 at Banderas Bay, México, were analyzed from SeaWiFS-ocean-color-sensor derived information. These events were related with the maximum chlorophyll week anomalies (ASi; a proxy variable constructed for the analysis of chlorophyll temporal variation in the bay). The winter-spring blooms were multispecific, while the summer-fall blooms were monospecific. Two proposals are made: (1) Winter-spring blooms are strongly related with mesoescale processes, due to their apparent temporal synchrony with the high chlorophyll levels in the coastal region from Sinaloa to Jalisco states; (2) Cochlodinium polykrikoides (Margalef 1961) blooms during the summer-fall periods could be induced by local conditions and the influence of previous events on the ecosystem.

  20. 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.

  1. Variability of factors driving spatial and temporal dispersion in river plume and Chattonella antiqua bloom in the Yatsushiro Sea, Japan.

    Science.gov (United States)

    Aoki, Kazuhiro; Onitsuka, Goh; Shimizu, Manabu; Kuroda, Hiroshi; Matsuo, Hitoshi; Kitadai, Yuuki; Sakurada, Kiyonari; Ando, Hidenori; Nishi, Hiromi; Tahara, Yoshio

    2014-04-15

    The dynamics of river plume in relation to harmful blooms of the raphidophycean flagellate, Chattonella antiqua in summer 2008-2010 in the Yatsushiro Sea, Japan were studied using a hydrodynamic model and monitoring data. In the southern area, the bloom formed in the waters stratified by a halocline caused by the southward expansion of riverine water from the Kuma River after the bloom initially forming in the northern area. The timing of the southward riverine water advection can be explained by the balance between the wind stress term and the pressure gradient term calculated from the horizontal density difference between the northern and southern areas. The wind stress and pressure gradient terms were evaluated using the sea surface temperature, salinity, wind speed and direction at two stations. Real time monitoring or continuous observations in these areas will enable nowcasts of bloom expansion when a bloom develops in the northern area.

  2. Eccentric connectivity index

    CERN Document Server

    Ilić, Aleksandar

    2011-01-01

    The eccentric connectivity index $\\xi^c$ is a novel distance--based molecular structure descriptor that was recently used for mathematical modeling of biological activities of diverse nature. It is defined as $\\xi^c (G) = \\sum_{v \\in V (G)} deg (v) \\cdot \\epsilon (v)$\\,, where $deg (v)$ and $\\epsilon (v)$ denote the vertex degree and eccentricity of $v$\\,, respectively. We survey some mathematical properties of this index and furthermore support the use of eccentric connectivity index as topological structure descriptor. We present the extremal trees and unicyclic graphs with maximum and minimum eccentric connectivity index subject to the certain graph constraints. Sharp lower and asymptotic upper bound for all graphs are given and various connections with other important graph invariants are established. In addition, we present explicit formulae for the values of eccentric connectivity index for several families of composite graphs and designed a linear algorithm for calculating the eccentric connectivity in...

  3. On eccentric connectivity index

    CERN Document Server

    Zhou, Bo

    2010-01-01

    The eccentric connectivity index, proposed by Sharma, Goswami and Madan, has been employed successfully for the development of numerous mathematical models for the prediction of biological activities of diverse nature. We now report mathematical properties of the eccentric connectivity index. We establish various lower and upper bounds for the eccentric connectivity index in terms of other graph invariants including the number of vertices, the number of edges, the degree distance and the first Zagreb index. We determine the n-vertex trees of diameter with the minimum eccentric connectivity index, and the n-vertex trees of pendent vertices, with the maximum eccentric connectivity index. We also determine the n-vertex trees with respectively the minimum, second-minimum and third-minimum, and the maximum, second-maximum and third-maximum eccentric connectivity indices for

  4. What are the effects of macroalgal blooms on the structure and functioning of marine ecosystems? A systematic review protocol

    Directory of Open Access Journals (Sweden)

    Lyons Devin A

    2012-06-01

    Full Text Available Abstract Background Anthropogenic activities are believed to have caused an increase in the magnitude, frequency, and extent of macroalgal blooms in marine and estuarine environments. These blooms may contribute to declines in seagrasses and non-blooming macroalgal beds, increasing hypoxia, and reductions in the diversity of benthic invertebrates. However, they may also provide other marine organisms with food and habitat, increase secondary production, and reduce eutrophication. The objective of this systematic review will be to quantify the positive and negative impacts of anthropogenically induced macroalgal blooms in order to determine their effects on ecosystem structure and functioning, and to identify factors that cause their effects to vary. Methods We will search a number of online databases to gather empirical evidence from the literature on the impacts of macroalgal blooms on: (1 species richness and other univariate measures of biodiversity; (2 productivity and abundance of algae, plants, and animals; and (3 biogeochemical cycling and other flows of energy and materials, including trophic interactions and cross-ecosystem subsidies. Data from relevant studies will be extracted and used in a random effects meta-analysis in order to estimate the average effect of macroalgal blooms on each response of interest. Where possible, sub-group analyses will be conducted in order to evaluate how the effects of macroalgal blooms vary according to: (1 which part of the ecosystem is being studied (e.g. which habitat type, taxonomic group, or trophic level; (2 the size of blooms; (3 the region in which blooms occurred; (4 background levels of ecosystem productivity; (5 physical and chemical conditions; (6 aspects of study design and quality (e.g. lab vs. field, experimental vs. observational, degree of replication; and (7 whether the blooms are believed to be anthropogenically induced or not.

  5. Effect of volcano ash additions on nutrient concentrations, bloom dynamics and community metabolism in a short-term experiment in the NW Mediterranean Sea

    Science.gov (United States)

    Weinbauer, Markus

    2016-04-01

    Volcano ash deposition is now considered as an important source of inorganic bioavailable iron which can relieve Fe-limitation in the ocean. As volcano ash also releases PO4, a experiment was performed in the NW Mediterranean Sea to test whether volcano ash deposition can affect nutrient dynamics and bloom development in a P-limited system. In a 54h experiment, it was shown that the development of a phytoplankton bloom was not enhanced or even repressed by ash additions of 2 and 20 mg l-1, whereas higher ash concentrations (200 mg l-1) induced a phytoplankton bloom as indicated by elevated Chlorophyll-a levels. Concurrently, net community production (NCP) and gross primary production (GPP) were enhanced at T24h at the highest ash additions. The metabolic balance was roughly neutral at low or no ash additions, but shifted towards phototrophy at the highest ash additions. The data on inorganic nutrient development and release estimates from ash material assays suggest relieving of P-limitation concomitant with NO3 and silicate use from ash. The concentration of TEP increased with increasing ash levels. The abundances of the heterotrophic compartment (bacteria, viruses and ciliates) also indicated dose-dependent responses. Our data suggest that heterotrophs won the competition for inorganic nutrients at ash levels of 2 and 20 mg l-1, whereas phytoplankton won at levels of 200 mg l-1. Overall, our experiments point to a strong potential of volcano ash deposition as forcing factor for nutrient dynamics and the activity of microbial plankton in a P-limited system.

  6. Enhanced chlorophyll a and primary production in the northern Arabian Sea during the spring intermonsoon due to green Noctiluca scintillans bloom

    Digital Repository Service at National Institute of Oceanography (India)

    Madhu, N.V.; Jyothibabu, R.; Maheswaran, P.A.; Jayaraj, K.A.; Achuthankutty, C.T.

    . This was caused primarily by a thick algal bloom spread over a vast area between 17-21 degrees N and 66-70 degrees E. Satellite images showed exceptionally high concentration of chlorophyll a in the bloom area, representing the annually occurring 'spring blooms...

  7. Institutions for Asian Connectivity

    OpenAIRE

    Bhattacharyay, Biswa

    2010-01-01

    To make Asia more economically sustainable and resilient against external shocks, regional economies need to be rebalanced toward regional demand- and trade-driven growth through increased regional connectivity. The effectiveness of connectivity depends on the quality of hard and soft infrastructure. Of particular importance in terms of soft infrastructure which makes hard infrastructure work are the facilitating institutions that support connectivity through appropriate policies, reforms, sy...

  8. Handbook of networking & connectivity

    CERN Document Server

    McClain, Gary R

    1994-01-01

    Handbook of Networking & Connectivity focuses on connectivity standards in use, including hardware and software options. The book serves as a guide for solving specific problems that arise in designing and maintaining organizational networks.The selection first tackles open systems interconnection, guide to digital communications, and implementing TCP/IP in an SNA environment. Discussions focus on elimination of the SNA backbone, routing SNA over internets, connectionless versus connection-oriented networks, internet concepts, application program interfaces, basic principles of layering, proto

  9. 78 FR 55684 - ConnectED Workshop

    Science.gov (United States)

    2013-09-11

    ... content into the curriculum; and as classroom management software tools move everything from homework... consider promising strategies for achieving the President's goal of connecting virtually all K-12 students... policies and consider the most promising strategies for equipping K-12 schools for digital learning....

  10. Inverse Degree and Connectivity

    Institute of Scientific and Technical Information of China (English)

    MA Xiao-ling; TIAN Ying-zhi

    2013-01-01

    Let G be a connected graph with vertex set V(G),order n =丨V(G)丨,minimum degree δ(G) and connectivity κ(G).The graph G is called maximally connected if κ(G) =δ(G).Define the inverse degree of G with no isolated vertices as R(G) =Σv∈V(G)1/d(v),where d(v) denotes the degree of the vertex v.We show that G is maximally connected if R(G) < 1 + 2/δ + n-2δ+1/(n-1)(n-3).

  11. Asymptotically hyperbolic connections

    Science.gov (United States)

    Fine, Joel; Herfray, Yannick; Krasnov, Kirill; Scarinci, Carlos

    2016-09-01

    General relativity in four-dimensions can be equivalently described as a dynamical theory of {SO}(3)˜ {SU}(2)-connections rather than metrics. We introduce the notion of asymptotically hyperbolic connections, and work out an analogue of the Fefferman-Graham expansion in the language of connections. As in the metric setup, one can solve the arising ‘evolution’ equations order by order in the expansion in powers of the radial coordinate. The solution in the connection setting is arguably simpler, and very straightforward algebraic manipulations allow one to see how the unconstrained by Einstein equations ‘stress-energy tensor’ appears at third order in the expansion. Another interesting feature of the connection formulation is that the ‘counter terms’ required in the computation of the renormalised volume all combine into the Chern-Simons functional of the restriction of the connection to the boundary. As the Chern-Simons invariant is only defined modulo large gauge transformations, the requirement that the path integral over asymptotically hyperbolic connections is well-defined requires the cosmological constant to be quantised. Finally, in the connection setting one can deform the 4D Einstein condition in an interesting way, and we show that asymptotically hyperbolic connection expansion is universal and valid for any of the deformed theories.

  12. Minimum cost connection networks

    DEFF Research Database (Denmark)

    Hougaard, Jens Leth; Tvede, Mich

    2015-01-01

    demands. We use a few axioms to characterize allocation rules that truthfully implement cost minimizing networks satisfying all connection demands in a game where: (1) a central planner announces an allocation rule and a cost estimation rule; (2) every agent reports her own connection demand as well...... as all connection costs; (3) the central planner selects a cost minimizing network satisfying reported connection demands based on the estimated costs; and, (4) the planner allocates the true costs of the selected network. It turns out that an allocation rule satisfies the axioms if and only if relative...

  13. Dust depositions leading to phytoplankton blooms in the Arabian sea.

    Digital Repository Service at National Institute of Oceanography (India)

    Banerjee, P.; PrasannaKumar, S.

    Atmospheric deposition of soil dust is an important source of nutrients (especially iron) to the open ocean regions. Every winter (December to March) the Arabian Sea, the northwest part of the Indian Ocean, receives large mineral dust flux from...

  14. Bloom syndrome in short children born small for gestational age: A challenging diagnosis

    NARCIS (Netherlands)

    J.S. Renes (Judith); R.H. Willemsen (Ruben); A. Wagner (Anja); M.J. Finken (Martijn); A.C.S. Hokken-Koelega (Anita)

    2013-01-01

    textabstractBackground: GH treatment has become a frequently applied growth-promoting therapy in short children born small for gestational age (SGA). In some disorders GH treatment is contraindicated, eg, chromosomal breakage syndromes. Bloom syndrome is a rare chromosomal breakage syndrome characte

  15. Forankring af e-lærings-aktiviteter med Blooms digitale taksonomi

    DEFF Research Database (Denmark)

    Christensen, Inger-Marie F.; Kjær, Christopher; Hansen, Pernille Stenkil

    2016-01-01

    For at sikre en hensigtsmæssig forankring af e-læringsaktiviteter ift. kursets læringsmål og eksamen har vi på SDU udviklet og afprøvet en metode, der er inspireret af integreret kursusdesign (Fink 2005, 2013), backward design (Wiggins & McTighe 2005) og Blooms digitale taksonomi (Churches 2001...

  16. An Efficient Data Fingerprint Query Algorithm Based on Two-Leveled Bloom Filter

    Directory of Open Access Journals (Sweden)

    Bin Zhou

    2013-04-01

    Full Text Available The function of the comparing fingerprints algorithm was to judge whether a new partitioned data chunk was in a storage system a decade ago.  At present, in the most de-duplication backup system the fingerprints of the big data chunks are huge and cannot be stored in the memory completely. The performance of the system is unavoidably retarded by data chunks accessing the storage system at the querying stage. Accordingly, a new query mechanism namely Two-stage Bloom Filter (TBF mechanism is proposed. Firstly, as a representation of the entirety for the first grade bloom filter, each bit of the second grade bloom filter in the TBF represents the chunks having the identical fingerprints reducing the rate of false positives. Secondly, a two-dimensional list is built corresponding to the two grade bloom filter for the absolute addresses of the data chunks with the identical fingerprints.  Finally, a new hash function class with the strong global random characteristic is set up according to the data fingerprints’ random characteristics. To reduce the comparing data greatly, TBF decreases the number of accessing disks, improves the speed of detecting the redundant data chunks, and reduces the rate of false positives which helps the improvement of the overall performance of system.

  17. Impact of elevated pH on succession in the Arctic spring bloom

    DEFF Research Database (Denmark)

    Riisgaard, Karen; Nielsen, Torkel Gissel; Hansen, Per Juel

    2015-01-01

    at the initiation of the spring bloom each year and manipulated to cover pH levels in the range of 8.0-9.5 to test the immediate tolerance of Arctic protist plankton to elevated pH under nutrient-limiting (2011) and nutrient-rich conditions (2012). The most pronounced effect of elevated pH was found......The development of pH during the spring bloom in 2011 and 2012 was investigated in Disko Bay, West Greenland. During the spring phytoplankton bloom pH reached 8.5 at the peak of the bloom. Subsequently, the pH decreased to 7.5. Microcosm experiments were conducted on natural assemblages sampled...... for heterotrophic protists, whereas phytoplankton proved more robust. Two out of three heterotrophic protist species were significantly affected if pH increased above 8.5, and all heterotrophic protists had disappeared at pH 9.5. Based on Chl a measurements from the two sets of experiments, phytoplankton community...

  18. Water management strategies against toxic Microcystis blooms in the Dutch delta.

    Science.gov (United States)

    Verspagen, Jolanda M H; Passarge, Jutta; Jöhnk, Klaus D; Visser, Petra M; Peperzak, Louis; Boers, Paul; Laanbroek, Hendrikus J; Huisman, Jef

    2006-02-01

    To prevent flooding of the Dutch delta, former estuaries have been impounded by the building of dams and sluices. Some of these water bodies, however, experience major ecological problems. One of the problem areas is the former Volkerak estuary that was turned into a freshwater lake in 1987. From the early 1990s onward, toxic Microcystis blooms dominate the phytoplankton of the lake every summer. Two management strategies have been suggested to suppress these harmful algal blooms: flushing the lake with fresh water or reintroducing saline water into the lake. This study aims at an advance assessment of these strategies through the development of a mechanistic model of the population dynamics of Microcystis. To calibrate the model, we monitored the benthic and pelagic Microcystis populations in the lake during two years. Field samples of Microcystis were incubated in the laboratory to estimate growth and mortality rates as functions of light, temperature, and salinity. Recruitment and sedimentation rates were measured in the lake, using traps, to quantify benthic-pelagic coupling of the Microcystis populations. The model predicts that flushing with fresh water will suppress Microcystis blooms when the current flushing rate is sufficiently increased. Furthermore, the inlet of saline water will suppress Microcystis blooms for salinities exceeding 14 g/L. Both management options are technically feasible. Our study illustrates that quantitative ecological knowledge can be a helpful tool guiding large-scale water management.

  19. Unusual blooms of green Noctiluca miliaris (Dinophyceae) in the Arabian Sea during the winter monsoon

    Digital Repository Service at National Institute of Oceanography (India)

    Gomes, H.R.; Matondkar, S.G.P.; Parab, S.G.; Goes, J.I.; Pednekar, S.; Al-Azri, A.R.N.; Thoppil, P.G.

    A large-scale, ongoing study conducted by the National Institute of Oceanography, India, from 2003 onward in support of India’s ocean color program, has documented for the first time ever the appearance of extensive blooms of Noctiluca miliaris...

  20. Effects of a cyanobacterial bloom sample containing microcystin-LR on the ecophysiology of Daphnia similis

    Directory of Open Access Journals (Sweden)

    Natalia Herrera

    2014-01-01

    Full Text Available Cyanobacterial blooms can affect a wide range of aquatic organisms due to the presence of toxic compounds. However, no study so far has shown the effects of natural blooms samples on the physiological parameters related to the ecology of Daphnia. In this study we used a natural bloom sample obtained from a reservoir in Colombia to evaluate its effects on five parameters related to Daphnia's feeding behavior, swimming movements and physiology: second antennae movement (swimming, mandible movement (feeding, thoracic appendages (feeding, postabdomen movement (rejection of food particles and heart rate (physiology. The results revealed significant changes in all parameters evaluated at two different concentrations of aqueous extracts of the bloom: second antennae movements increased significantly and there were significant reductions in mandibular movements, thoracic movements and heart rate. Although postabdominal movements showed high variability with no distinctive pattern between control and treatments, the reduction in the other parameters (such as heart rate over time could possibly reflect an intoxication by microcystins or a behavioral response (e.g., feeding inhibition.

  1. Bloom, Frye, and the Academic Aspiration after the Unity of Knowledge.

    Science.gov (United States)

    Morgan, Peter

    1991-01-01

    Examines the dark analyses of modern higher education presented in Allan Bloom's "The Closing of the American Mind" and Northrop Frye's "On Education." The University of Toronto proposes an Integrated Studies (Unity of Knowledge) program which would involve students in interdisciplinary studies in humanities, social sciences,…

  2. Impact of river discharge on phytoplankton bloom dynamics in eutrophic estuaries: A model study

    NARCIS (Netherlands)

    Liu, B.; de Swart, H.E.

    2015-01-01

    Field observations in estuaries reveal that phytoplankton blooms are strongly affected by advection processes related to river flow. To gain quantitative insight into this dependence, experiments were performed with a new idealised model that couples physical and biological processes. Advection of p

  3. "Byatt versus Bloom: or, Reading by Patricide versus Reading by Love"

    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....

  4. Sucrose in bloom-forming cyanobacteria: loss and gain of genes involved in its biosynthesis.

    Science.gov (United States)

    Kolman, María A; Salerno, Graciela L

    2016-02-01

    Bloom-forming cyanobacteria are widely distributed in freshwater ecosystems. To cope with salinity fluctuations, cyanobacteria synthesize compatible solutes, such as sucrose, to maintain the intracellular osmotic balance. The screening of cyanobacterial genomes revealed that homologues to sucrose metabolism-related genes only occur in few bloom-forming strains, mostly belonging to Nostocales and Stigonematales orders. Remarkably, among Chroococcales and Oscillatoriales strains, homologues were only found in M. aeruginosa PCC 7806 and Leptolyngbya boryana PCC 6306, suggesting a massive loss of sucrose metabolism in bloom-forming strains of these orders. After a complete functional characterization of sucrose genes in M. aeruginosa PCC 7806, we showed that sucrose metabolism depends on the expression of a gene cluster that defines a transcriptional unit, unique among all sucrose-containing cyanobacteria. It was also demonstrated that the expression of the encoding genes of sucrose-related proteins is stimulated by salt. In view of its ancestral origin in cyanobacteria, the fact that most bloom-forming strains lack sucrose metabolism indicates that the genes involved might have been lost during evolution. However, in a particular strain, like M. aeruginosa PCC 7806, sucrose synthesis genes were probably regained by horizontal gene transfer, which could be hypothesized as a response to salinity fluctuations.

  5. FEM Simulation Of Stress-Strain Fields in the Blooms with Casting Defect During Soaking

    Directory of Open Access Journals (Sweden)

    Miroslav KVÍČALA

    2013-06-01

    Full Text Available Round continuously cast blooms heating strategy is crucial in prevention of internal cracks initiation and propagation. Especially vanadium microalloyed Cr-Mo based steels are very sensitive to internal crack occurrence. This paper deals with two heating strategies that were realized in soaking pit. Using FEM simulation it was proved that proper heating strategy is essential to reduce internal crack propagation.

  6. Impact of Harmful Algal Blooms on Several Lake Erie Drinking Water Treatment Plants

    Science.gov (United States)

    Recent events in Ohio have demonstrated the challenge treatment facilities face in providing safe drinking water when encountering extreme harmful algal bloom (HAB) events. Over the last two years the impact of HAB-related microcystins on several drinking water treatment facilit...

  7. Bloom on Literature and Rock Music: The Challenge Facing Higher Education.

    Science.gov (United States)

    Olivier, B.

    1997-01-01

    Disputing Allan Bloom's ("Closing of the American Mind") conviction that the fading of literary culture and growing attachment to rock music signals the decline of American civilization, discussion examines how literature, rock music, film, and critical reflection can be used to engage students intellectually without relinquishing either…

  8. Effect of Multiple Intelligence Theory Practice on Student Success by Bloom's Taxonomy

    Science.gov (United States)

    Uzunoz, Abdulkadir

    2011-01-01

    In this study, it is aimed to determine the effects of the "Multiple Intelligence Theory" on the retention and achievement of the students according to Bloom Taxonomy. This study is a research as an experimental model. Research in academic year of 2008/2009 in Foca Izmir Lesbos Reha Country High School 9 Class is conducted on students.…

  9. Effect of Multiple Intelligence Theory Practice on Student Success by Bloom's Taxonomy

    Science.gov (United States)

    Uzunoz, Abdulkadir

    2011-01-01

    In this study, it is aimed to determine the effects of the "Multiple Intelligence Theory" on the retention and achievement of the students according to Bloom Taxonomy. This study is a research as an experimental model. Research in academic year of 2008/2009 in Foca Izmir Lesbos Reha Country High School 9 Class is conducted on students. In this…

  10. 3. Chromosomal instability in B-lymphoblasotoid cell lines from Werner's and Bloom's syndrome patients

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@Werner's syndrome (WS) and Bloom's syndrome (BS) are rare autosomal recessive diseases in which the feature of premature aging and the elevated risk of neoplasia may be associated with genomic instability. To cha-racterize the genomic instability of WS and BS, B-lymphoblastoid cell lines (LCLs) from WS and BS patients were cytogenetically analyzed, comparing to those from healthy donors. Although all

  11. Dog Poisonings Associated with a Microcystis aeruginosa Bloom in the Netherlands

    NARCIS (Netherlands)

    Lurling, M.; Faassen, Elisabeth J.

    2013-01-01

    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 x 10(3) mu g g(-1) dry-weight microcystin, the vomit of one of the dogs contained on average 94 mu g mic

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

    Science.gov (United States)

    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...

  13. Long term characterization of Trichodesmium erythraeum blooms in Gabès Gulf (Tunisia)

    Science.gov (United States)

    Sabeur, Hamza Ismail; Wafa, Feki-Sahnoun; Asma, Hamza; Malika, Bel Hassen

    2016-08-01

    The present paper reports on a twenty six year monitoring of the diazotrophic cyanobacteria, Trichodesmium erythraeum in the Gulf of Gabès associated with environmental parameters and meteorological variables. Trichodesmium erythraeum blooms were not recurrent all years and were observed on average 2.11 times per year over the period between 1988 and 2013. Blooms were associated with temperature exceeding 24 °C and wind speed generally less than 5 m s-1. Trichodesmium erythraeum reached very high densities fluctuating between 0.12×106 and 720×106 trichomes dm-3. The wind speed during dust events and the number of dust days per year were highly correlated to Trichodesmium abundances. Two wind regimes during dust events were identified. The South -South East direction crossing the Tunisian desert generated the most intensive blooms. High dissolved inorganic nitrogen concentrations (2-14.6 μM) and orthophosphate concentrations (0.05-2.79 μM) were observed during bloom events leading to high N/P ratio well above the Redfield ratio and fluctuating linearly as function of Trichodesmium abundance. The anomalous N/P ratio could result from Trichodesmium erythraeum biological N2 fixation and/or the contribution of atmospheric deposition.

  14. Bloom-Gilman Duality of Nucleon Spin Structure Function and Elastic Peak Contribution

    Institute of Scientific and Technical Information of China (English)

    DONG Yu-Bing

    2005-01-01

    By employing the parametrization form of the nucleon spin structure function in the resonance region,which includes the contributions of the resonance peaks and of nonresonance background, we study Bloom-Gilman quark-hadron duality of g1 both in the inelastic resonance region and elastic one.

  15. Newly recorded Karlodinium veneficum dinoflagellate blooms in stratified water of the East China Sea

    Science.gov (United States)

    Dai, Xinfeng; Lu, Douding; Guan, Weibing; Wang, Hongxia; He, Piaoxia; Xia, Ping; Yang, Huajie

    2014-03-01

    Karlodinium veneficum is a cosmopolitan species, but has been poorly recorded in the East China Sea (ECS) due to its small size and difficulty in identification. The bloom dynamics of this species is not well understood globally. In this study, we examined its morphological characteristics that suggest the K. veneficum is the co-occurring bloom causative species of large scale Prorocentrum donghaiense blooms in spring 2011. The epicone of K. veneficum recorded in the investigated area is conical or rounded, and the hypocone is hemispherically rounded. The ventral pore is located at the left side of the apical groove. Nucleus is positioned centrally within the hypocone. Four large irregular chloroplasts are equally distributed in the epicone and hypocone. The mean length of cultured cells was 13.6±1.2 μm (range 11.0-15.8 μm) and the mean width was 10.0±1.1 μm (range 8.0-12 μm) (n=50). Cell abundance of K. veneficum population was low, in the region 1000-1600 cells L-1, along a transect in the East China Sea on April 19, 2011, when the water column was not distinctly stratified. Cell densities reached 3×107 cells L-1 along the same transect on May 13 2011 when the bloom occurred in the 10 m layer surface and the water column was distinctly stratified. Cell abundances therefore appear closely related to water column stratification.

  16. 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.

    cohnii, Bacillus flexus, and Bacillus cereus. The approx. 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...

  17. FATTY ACID AND STEROL COMPOSITION OF A KARENIA BREVIS BLOOM IN THE GULF OF MEXICO

    Science.gov (United States)

    In the Gulf of Mexico, recurring algal blooms, caused by Karenia brevis (formerly known as Gymnodinium breve), have significant adverse health and economic impacts. K. brevis is one member of a small group of dinoflagellates, related morphologically and by DNA-based phylogenetic ...

  18. Controls of primary production in two phytoplankton blooms in the Antarctic Circumpolar Current

    NARCIS (Netherlands)

    Hoppe, C.J.M.; Klaas, C.; Ossebaar, S.; Soppa, M.A.; Cheah, W.; Laglera, L.M.; Santos-Echeandia, J.; Rost, B.; Wolf-Gladrow, D.A.; Bracher, A.; Hoppema, M.; Strass, V.

    2016-01-01

    The Antarctic Circumpolar Current has a high potential for primary production and carbon sequestration through the biological pump. In the current study, two large-scale blooms observed in 2012 during a cruise with R.V. Polarstern were investigated with respect to phytoplankton standing stocks, prim

  19. Critical depth and critical turbulence : Two different mechanisms for the development of phytoplankton blooms

    NARCIS (Netherlands)

    Huisman, J.; van Oostveen, P.; Weissing, F.J.

    1999-01-01

    A turbulent diffusion model shows that there are two different mechanisms for the development of phytoplankton blooms. One of these mechanisms works in well-mixed environments and corresponds to the classical critical depth theory. The other mechanism is based on the rate of turbulent mixing. If tur

  20. Critical depth and critical turbulence: two different mechanisms for the development of phytoplankton blooms

    NARCIS (Netherlands)

    Huisman, J.; Van Oostveen, P.; Weissing, F.J.

    1999-01-01

    A turbulent diffusion model shows that there are two different mechanisms for the development of phytoplankton blooms. One of these mechanisms works in well-mixed environments and corresponds to the classical critical depth theory. The other mechanism is based on the rate of turbulent mixing. If tur