WorldWideScience

Sample records for click source levels

  1. Sperm whale clicks: Directionality and source level revisited

    DEFF Research Database (Denmark)

    Møhl, Bertel; Wahlberg, Magnus; Madsen, Peter T.;

    2000-01-01

    In sperm whales ~Physeter catodon L. 1758! the nose is vastly hypertrophied, accounting for about one-third of the length or weight of an adult male. Norris and Harvey @in Animal Orientation and Navigation, NASA SP-262 ~1972!, pp. 397–417# ascribed a sound-generating function to this organ complex....... A sound generator weighing upward of 10 tons and with a cross-section of 1 m is expected to generate high-intensity, directional sounds. This prediction from the Norris and Harvey theory is not supported by published data for sperm whale clicks ~source levels of 180 dB re 1 mPa and little, if any...... implicates sonar as a possible function of the clicks. Thus, previously published properties of sperm whale clicks underestimate the capabilities of the sound generator and therefore cannot falsify the Norris and Harvey theory....

  2. Hearing sensation levels of emitted biosonar clicks in an echolocating Atlantic bottlenose dolphin.

    Directory of Open Access Journals (Sweden)

    Songhai Li

    Full Text Available Emitted biosonar clicks and auditory evoked potential (AEP responses triggered by the clicks were synchronously recorded during echolocation in an Atlantic bottlenose dolphin (Tursiops truncatus trained to wear suction-cup EEG electrodes and to detect targets by echolocation. Three targets with target strengths of -34, -28, and -22 dB were used at distances of 2 to 6.5 m for each target. The AEP responses were sorted according to the corresponding emitted click source levels in 5-dB bins and averaged within each bin to extract biosonar click-related AEPs from noise. The AEP amplitudes were measured peak-to-peak and plotted as a function of click source levels for each target type, distance, and target-present or target-absent condition. Hearing sensation levels of the biosonar clicks were evaluated by comparing the functions of the biosonar click-related AEP amplitude-versus-click source level to a function of external (in free field click-related AEP amplitude-versus-click sound pressure level. The results indicated that the dolphin's hearing sensation levels to her own biosonar clicks were equal to that of external clicks with sound pressure levels 16 to 36 dB lower than the biosonar click source levels, varying with target type, distance, and condition. These data may be assumed to indicate that the bottlenose dolphin possesses effective protection mechanisms to isolate the self-produced intense biosonar beam from the animal's ears during echolocation.

  3. A `Clicked' Tetrameric Hydroxamic Acid Glycopeptidomimetic Antagonizes Sugar-Lectin Interactions On The Cellular Level

    Science.gov (United States)

    Zhang, Hai-Lin; Zang, Yi; Xie, Juan; Li, Jia; Chen, Guo-Rong; He, Xiao-Peng; Tian, He

    2014-07-01

    A tetrameric N-acetyl galactosaminyl (GalNAc) peptidomimetic was constructed by N-acetylation of repeating proline-based hydroxamic acid units, followed by a convergent `click chemistry' coupling. This novel glycopeptidomimetic was determined to effectively antagonize the interaction between a transmembrane hepatic lectin and GalNAc on the cellular level.

  4. The monopulsed nature of sperm whale clicks

    Science.gov (United States)

    Møhl, Bertel; Wahlberg, Magnus; Madsen, Peter T.; Heerfordt, Anders; Lund, Anders

    2003-08-01

    Traditionally, sperm whale clicks have been described as multipulsed, long duration, nondirectional signals of moderate intensity and with a spectrum peaking below 10 kHz. Such properties are counterindicative of a sonar function, and quite different from the properties of dolphin sonar clicks. Here, data are presented suggesting that the traditional view of sperm whale clicks is incomplete and derived from off-axis recordings of a highly directional source. A limited number of assumed on-axis clicks were recorded and found to be essentially monopulsed clicks, with durations of 100 μs, with a composite directionality index of 27 dB, with source levels up to 236 dB re: 1 μPa (rms), and with centroid frequencies of 15 kHz. Such clicks meet the requirements for long-range biosonar purposes. Data were obtained with a large-aperture, GPS-synchronized array in July 2000 in the Bleik Canyon off Vestera˚len, Norway (69°28' N, 15°40' E). A total of 14 h of sound recordings was collected from five to ten independent, simultaneously operating recording units. The sound levels measured make sperm whale clicks by far the loudest of sounds recorded from any biological source. On-axis click properties support previous work proposing the nose of sperm whales to operate as a generator of sound.

  5. Click sounds produced by cod (Gadus morhua)

    Science.gov (United States)

    Vester, Heike I.; Folkow, Lars P.; Blix, A. S.

    2004-02-01

    Conspicuous sonic click sounds were recorded in the presence of cod (Gadus morhua), together with either harp seals (Pagophilus groenlandicus), hooded seals (Cystophora cristata) or a human diver in a pool. Similar sounds were never recorded in the presence of salmon (Salmo salar) together with either seal species, or from either seal or fish species when kept separately in the pool. It is concluded that cod was the source of these sounds and that the clicks were produced only when cod were approached by a swimming predatorlike body. The analyzed click sounds (n=377) had the following characteristics (overall averages +/- S.D.): peak frequency=5.95+/-2.22 kHz peak-to-peak duration=0.70+/-0.45 ms sound pressure level (received level)=153.2+/-7.0 dB re 1 μPa at 1 m. At present the mechanism and purpose of these clicks is not known. However, the circumstances under which they were recorded and some observations on the behavior of the seals both suggest that the clicks could have a predator startling function.

  6. Click sounds produced by cod (Gadus morhua).

    Science.gov (United States)

    Vester, Heike I; Folkow, Lars P; Blix, A S

    2004-02-01

    Conspicuous sonic click sounds were recorded in the presence of cod (Gadus morhua), together with either harp seals (Pagophilus groenlandicus), hooded seals (Cystophora cristata) or a human diver in a pool. Similar sounds were never recorded in the presence of salmon (Salmo salar) together with either seal species, or from either seal or fish species when kept separately in the pool. It is concluded that cod was the source of these sounds and that the clicks were produced only when cod were approached by a swimming predatorlike body. The analyzed click sounds (n = 377) had the following characteristics (overall averages +/- S.D.): peak frequency = 5.95 +/- 2.22 kHz; peak-to-peak duration = 0.70 +/- 0.45 ms; sound pressure level (received level) = 153.2 +/- 7.0 dB re 1 microPa at 1 m. At present the mechanism and purpose of these clicks is not known. However, the circumstances under which they were recorded and some observations on the behavior of the seals both suggest that the clicks could have a predator startling function. PMID:15000203

  7. Recording and quantification of ultrasonic echolocation clicks from free-ranging toothed whales

    DEFF Research Database (Denmark)

    Madsen, Peter Teglberg; Wahlberg, Magnus

    2007-01-01

    Toothed whales produce short, ultrasonic clicks of high directionality and source level to probe their environment acoustically. This process, termed echolocation, is to a large part governed by the properties of the emitted clicks. Therefore derivation of click source parameters from free-ranging...... animals is of increasing importance to understand both how toothed whales use echolocation in the wild and how they may be monitored acoustically. This paper addresses how source parameters can be derived from free-ranging toothed whales in the wild using calibrated multi-hydrophone arrays and digital......, and the range to, the clicking animal, and precise information on hydrophone locations is critical. We provide examples of localization routines and outline sources of error that lead to uncertainties in localizing clicking animals in time and space. Furthermore we explore approaches to time series analysis...

  8. Nanoplasmonics tuned ``click chemistry''

    Science.gov (United States)

    Tijunelyte, I.; Guenin, E.; Lidgi-Guigui, N.; Colas, F.; Ibrahim, J.; Toury, T.; Lamy de La Chapelle, M.

    2016-03-01

    Nanoplasmonics is a growing field of optical condensed matter science dedicated to optical phenomena at the nanoscale level in metal systems. Extensive research on noble metallic nanoparticles (NPs) has emerged within the last two decades due to their ability to keep the optical energy concentrated in the vicinity of NPs, in particular, the ability to create optical near-field enhancement followed by heat generation. We have exploited these properties in order to induce a localised ``click'' reaction in the vicinity of gold nanostructures under unfavourable experimental conditions. We demonstrate that this reaction can be controlled by the plasmonic properties of the nanostructures and we propose two physical mechanisms to interpret the observed plasmonic tuning of the ``click'' chemistry.Nanoplasmonics is a growing field of optical condensed matter science dedicated to optical phenomena at the nanoscale level in metal systems. Extensive research on noble metallic nanoparticles (NPs) has emerged within the last two decades due to their ability to keep the optical energy concentrated in the vicinity of NPs, in particular, the ability to create optical near-field enhancement followed by heat generation. We have exploited these properties in order to induce a localised ``click'' reaction in the vicinity of gold nanostructures under unfavourable experimental conditions. We demonstrate that this reaction can be controlled by the plasmonic properties of the nanostructures and we propose two physical mechanisms to interpret the observed plasmonic tuning of the ``click'' chemistry. Electronic supplementary information (ESI) available: NMR study on reaction initiation, SERS spectra and temperature calculations. See DOI: 10.1039/c5nr09018k

  9. "Click" i polymerer 2

    DEFF Research Database (Denmark)

    Hvilsted, Søren

    2012-01-01

    "Click"-reaktioner til fremstilling af ledende polymerer med funktionelle håndtag og bipolymermaterialer......"Click"-reaktioner til fremstilling af ledende polymerer med funktionelle håndtag og bipolymermaterialer...

  10. Comparison of echolocation clicks from geographically sympatric killer whales and long-finned pilot whales

    DEFF Research Database (Denmark)

    Eskesen, Ida; Wahlberg, Magnus; Simon, Malene;

    2010-01-01

    The source characteristics of biosonar signals from sympatric killer whales and long-finned pilot whales in a Norwegian fjord were compared. A total of 137 pilot whale and more than 2000 killer whale echolocation clicks were recorded using a linear four-hydrophone array. Of these, 20 pilot whale...... clicks and 28 killer whale clicks were categorized as being recorded on-axis. The clicks of pilot whales had a mean apparent source level of 196 dB re 1 lPa pp and those of killer whales 203 dB re 1 lPa pp. The duration of pilot whale clicks was significantly shorter (23 ls, S.E.¼1.3) and the centroid...... frequency significantly higher (55 kHz, S.E.¼2.1) than killer whale clicks (duration: 41 ls, S.E.¼2.6; centroid frequency: 32 kHz, S.E.¼1.5). The rate of increase in the accumulated energy as a function of time also differed between clicks from the two species. The differences in duration, frequency, and...

  11. Dose rate levels around industrial gamma sources

    International Nuclear Information System (INIS)

    Dose rate levels around two gamma ray sources utilized in a mining corporation have been determined. Both gamma ray sources are 137Cs and are installed in a mining corporation to measure on-line the density of mine products. Dose rate levels were calculated in several sites around the 137Cs sources using two active and several passive thermoluminescent dosemeters. Using the 137Cs' gamma factor dose rates were calculated in all the points. A comparison between the measured and calculated dose rate levels was carried out. Calculated dose rate levels was obtained for three cases: first, assuming the sources were bare, second, assuming the sources inside their shielding and the third, adding an extra shield to reduce the dose rate levels to those similar to local background. (author)

  12. Click Here To Buy.

    Science.gov (United States)

    Bridgman, Anne

    2000-01-01

    E-commerce is coming slowly to education, but some curious school purchasing officials are clicking on vendors' web sites. Pioneering districts include the Chicago, Detroit, and El Dorado (California) public schools. Vendors include Boise Cascade and Office Depot. Some vendors are joining institutional exchanges like Commerce One or marketing…

  13. Think Before You Click

    CERN Multimedia

    2001-01-01

    Be aware of what attachments you open and what Internet programs you agree to download, the simple click of a mouse can be enough to introduce a virus at CERN and cause widespread damage. Modern viruses are a serious threat to our computers and networks. CERN limits the security risks that these programs pose through the use of its firewall, by constantly updating its anti-virus software, by detecting un-patched security holes, and by blocking many dangerous attachments as they pass through e-mail gateways, but these defenses do not guarantee 100% security. Our habits of clicking "ok" automatically on the Internet and opening attachments without thinking, are the behaviors that modern viruses are using to get past our security protections. Viruses can sit on the Internet waiting for us to activate them as we surf the web. Many of us simply click 'ok' when presented with dialogue boxes and this is exactly what the virus wants: clicking can be enough to download and infect our computers. Viruses can travel as...

  14. Fighting Online Click-Fraud Using Bluff Ads

    CERN Document Server

    Haddadi, Hamed

    2010-01-01

    Online advertising is currently the greatest source of revenue for many Internet giants. The increased number of specialized websites and modern profiling techniques, have all contributed to an explosion of the income of ad brokers from online advertising. The single biggest threat to this growth, is however, click-fraud. Trained botnets and even individuals are hired by click-fraud specialists in order to maximize the revenue of certain users from the ads they publish on their websites, or to launch an attack between competing businesses. In this note we wish to raise the awareness of the networking research community on potential research areas within this emerging field. As an example strategy, we present Bluff ads; a class of ads that join forces in order to increase the effort level for click-fraud spammers. Bluff ads are either targeted ads, with irrelevant display text, or highly relevant display text, with irrelevant targeting information. They act as a litmus test for the legitimacy of the individual...

  15. Cover of source for level indicators

    International Nuclear Information System (INIS)

    Improved safety handling of sources for level indicators used especially in blast furnaces and other facilities is provided by a cover claimed in CS patent document 242082. The cover consists of a case housing a depleted uranium shielding. A channel emptying in the chamber is provided in the shielding in the cover case axis. The channel houses a container with a radiation source shielded with a tungsten source holder shielding at one end and with the cylindrical shielding of a retractable closure at the other. The closure is secured in the shielding position with a safety pin provided with opening for the lock yoke. The safety pin is slidably located in a guide rail with an opening for pin extension. The cover case is firmly linked to a flange provided with a cap. The source holder is protected with a guard fitted to the holder, with the possibility of dismantle. (Z.M.). 1 fig

  16. Copper Nanoparticles in Click Chemistry.

    Science.gov (United States)

    Alonso, Francisco; Moglie, Yanina; Radivoy, Gabriel

    2015-09-15

    effective in the multicomponent and regioselective synthesis of 1,4-disubstituted 1,2,3-triazoles in water from organic halides as azido precursors; magnetically recoverable CuNPs (3.0 ± 0.8 nm) supported on MagSilica could be alternatively used for the same purpose under similar conditions. Incorporation of an aromatic substituent at the 1-position of the triazole could be accomplished using the same CuNPs/C catalytic system starting from aryldiazonium salts or anilines as azido precursors. CuNPs/C in water also catalyzed the regioselective double-click synthesis of β-hydroxy-1,2,3-triazoles from epoxides. Furthermore, alkenes could be also used as azido precursors through a one-pot CuNPs/C-catalyzed azidosulfenylation-CuAAC sequential protocol, providing β-methylsulfanyl-1,2,3-triazoles in a stereo- and regioselective manner. In all types of reaction studied, CuNPs/C exhibited better behavior than some commercial copper catalysts with regard to the metal loading, reaction time, yield, and recyclability. Therefore, the results of this study also highlight the utility of nanosized copper in click chemistry compared with bulk copper sources. PMID:26332570

  17. Echolocation clicks of free-ranging Cuvier's beaked whales (Ziphius cavirostris)

    Science.gov (United States)

    Zimmer, Walter M. X.; Johnson, Mark P.; Madsen, Peter T.; Tyack, Peter L.

    2005-06-01

    Strandings of beaked whales of the genera Ziphius and Mesoplodon have been reported to occur in conjunction with naval sonar use. Detection of the sounds from these elusive whales could reduce the risk of exposure, but descriptions of their vocalizations are at best incomplete. This paper reports quantitative characteristics of clicks from deep-diving Cuvier's beaked whales (Ziphius cavirostris) using a unique data set. Two whales in the Ligurian Sea were simultaneously tagged with sound and orientation recording tags, and the dive tracks were reconstructed allowing for derivation of the range and relative aspect between the clicking whales. At depth, the whales produced trains of regular echolocation clicks with mean interclick intervals of 0.43 s (+/-0.09) and 0.40 s (+/-0.07). The clicks are frequency modulated pulses with durations of ~200 μs and center frequencies around 42 kHz, -10 dB bandwidths of 22 kHz, and Q3 dB of 4. The sound beam is narrow with an estimated directionality index of more than 25 dB, source levels up to 214 dBpp re: 1 μPa at 1 m, and energy flux density of 164 dB re: 1 μPa2 s. As the spectral and temporal properties are different from those of nonziphiid odontocetes the potential for passive detection is enhanced. .

  18. Feeding at a high pitch: Source parameters of narrow band,high-frequency clicks from echolocating off-shore hourglassdolphins and coastal Hector's dolphins

    DEFF Research Database (Denmark)

    Kyhn, Line Anker; Tougaard, Jakob; Jensen, Frants Havmand;

    2009-01-01

    (Lagenorhynchus cruciger) and Hector's dolphins (Cephalorhynchus hectori ) were made in the Drake Passage between Tierra del Fuego and the Antarctic Peninsular and Banks Peninsular Akaroa Harbour, New Zealand with a four element hydrophone array. Analysis of source parameters shows that both species produce......'s dolphins. The observed source parameter differences within these two NBHF species may be an adaptation to a coastal cluttered environment versus a deep water, pelagic habitat....

  19. Click Chemistry的翻译%Translation of Click Chemistry

    Institute of Scientific and Technical Information of China (English)

    李化毅

    2008-01-01

    诺贝尔奖得主Sharpless等于2001年首次提出click chemistry一词,之后这一概念广泛应用于高效合成有机小分子化合物和各种结构的高分子,国内的学者也在积极开展关于click chemistry的研究。赵卫光等发表了一篇综述,简要介绍了click chemistry在有机小分子合成中的一些应用。

  20. Noninvasive Fluid Level Sensor for Organometallic Sources

    Science.gov (United States)

    Gerdes, W.

    1986-01-01

    Two ultrasonic methods available for measuring level of organometallic liquid in stainless-steel (or other homogeneous solid) container. Methods require no disassembly or weighing of container. Commercially available ultrasonic flaw detectors, some of which have digital readouts and computer interfaces, used in techniques. Both methods used in crystal growth to determine level of liquids contained in sealed, opaque containers.

  1. Radioactivity Levels in Groundwater Sources in Ireland

    International Nuclear Information System (INIS)

    The Radiological Protection Institute of Ireland RPII in collaboration with the Environmental Protection Agency, EPA undertook a national survey of radioactivity in groundwater sources for compliance with parameters set out in the European Communities Drinking Water Directive. The Directive outlines the minimum requirements for the quality of drinking water and water intended for human consumption. Over two hundred samples were screened for radioactivity. Where indicated, analysis for individual radionuclide activity was undertaken and the radiation dose arising calculated. Furthermore, samples were analysed for radon concentration. Results show that all groundwater sources surveyed were found to be fit for human consumption and any action to reduce radioactivity is deemed unnecessary. This survey is the first comprehensive national survey of radioactivity in groundwater sources in Ireland. Approximately 18 per cent of drinking water in Ireland originates from groundwater and springs with the remainder from surface water. Between 2007 and 2011, the RPII measured the radiological quality of samples collected from the EPA's groundwater monitoring network. The EPA implements a national groundwater monitoring programme for water quality. As part of their monitoring programme, samples from a representative network of groundwater sources are collected and analysed for a range of parameters including uranium. These groundwater monitoring points have been determined by assessing the requirements for achieving a network that is representative of the variations in hydrogeology and man-made pressures across a groundwater body. The European Communities Drinking Water Directive has been transposed into Irish law in Statutory Instrument 278 of 2007. Two indicative standard parameters for radioactivity are established: tritium concentration of 100 becquerel per litre and total indicative dose of 0.1 millisievert per year

  2. Clicking in shallow rivers: short-range echolocation of Irrawaddy and Ganges River dolphins in a shallow, acoustically complex habitat.

    Directory of Open Access Journals (Sweden)

    Frants H Jensen

    Full Text Available Toothed whales (Cetacea, odontoceti use biosonar to navigate their environment and to find and catch prey. All studied toothed whale species have evolved highly directional, high-amplitude ultrasonic clicks suited for long-range echolocation of prey in open water. Little is known about the biosonar signals of toothed whale species inhabiting freshwater habitats such as endangered river dolphins. To address the evolutionary pressures shaping the echolocation signal parameters of non-marine toothed whales, we investigated the biosonar source parameters of Ganges river dolphins (Platanista gangetica gangetica and Irrawaddy dolphins (Orcaella brevirostris within the river systems of the Sundarban mangrove forest. Both Ganges and Irrawaddy dolphins produced echolocation clicks with a high repetition rate and low source level compared to marine species. Irrawaddy dolphins, inhabiting coastal and riverine habitats, produced a mean source level of 195 dB (max 203 dB re 1 µPapp whereas Ganges river dolphins, living exclusively upriver, produced a mean source level of 184 dB (max 191 re 1 µPapp. These source levels are 1-2 orders of magnitude lower than those of similar sized marine delphinids and may reflect an adaptation to a shallow, acoustically complex freshwater habitat with high reverberation and acoustic clutter. The centroid frequency of Ganges river dolphin clicks are an octave lower than predicted from scaling, but with an estimated beamwidth comparable to that of porpoises. The unique bony maxillary crests found in the Platanista forehead may help achieve a higher directionality than expected using clicks nearly an octave lower than similar sized odontocetes.

  3. Three-dimensional beam pattern of regular sperm whale clicks confirms bent-horn hypothesis

    Science.gov (United States)

    Zimmer, Walter M. X.; Tyack, Peter L.; Johnson, Mark P.; Madsen, Peter T.

    2005-03-01

    The three-dimensional beam pattern of a sperm whale (Physeter macrocephalus) tagged in the Ligurian Sea was derived using data on regular clicks from the tag and from hydrophones towed behind a ship circling the tagged whale. The tag defined the orientation of the whale, while sightings and beamformer data were used to locate the whale with respect to the ship. The existence of a narrow, forward-directed P1 beam with source levels exceeding 210 dBpeak re: 1 μPa at 1 m is confirmed. A modeled forward-beam pattern, that matches clicks >20° off-axis, predicts a directivity index of 26.7 dB and source levels of up to 229 dBpeak re: 1 μPa at 1 m. A broader backward-directed beam is produced by the P0 pulse with source levels near 200 dBpeak re: 1 μPa at 1 m and a directivity index of 7.4 dB. A low-frequency component with source levels near 190 dBpeak re: 1 μPa at 1 m is generated at the onset of the P0 pulse by air resonance. The results support the bent-horn model of sound production in sperm whales. While the sperm whale nose appears primarily adapted to produce an intense forward-directed sonar signal, less-directional click components convey information to conspecifics, and give rise to echoes from the seafloor and the surface, which may be useful for orientation during dives..

  4. AutoClickChem: Click Chemistry in Silico

    OpenAIRE

    Durrant, Jacob D; J Andrew McCammon

    2012-01-01

    Academic researchers and many in industry often lack the financial resources available to scientists working in "big pharma." High costs include those associated with high-throughput screening and chemical synthesis. In order to address these challenges, many researchers have in part turned to alternate methodologies. Virtual screening, for example, often substitutes for high-throughput screening, and click chemistry ensures that chemical synthesis is fast, cheap, and comparatively easy. Thou...

  5. Compact Web browsing profiles for click-through rate prediction

    DEFF Research Database (Denmark)

    Fruergaard, Bjarne Ørum; Hansen, Lars Kai

    2014-01-01

    In real time advertising we are interested in finding features that improve click-through rate prediction. One source of available information is the bipartite graph of websites previously engaged by identifiable users. In this work, we investigate three different decompositions of such a graph w...

  6. Cows, clicks, ciphers, and satire

    Directory of Open Access Journals (Sweden)

    Tom Tyler

    2015-04-01

    Full Text Available The social network game Farmville, which allows players to grow crops, raise animals, and produce a variety of goods, proved enormously successful within a year of its launch in 2009, attracting 110 million Facebook users. However, the game has been criticised for its mindless mechanics, which require little more than repeated clicking on its colourful icons. By way of parody, Ian Bogost’s Cow Clicker permits its players to simply click on a picture of a cow once every six hours. In this essay I extend Bogost’s critique and suggest that Cow Clicker highlights not just the soulless inanity of Farmville gameplay but also the paucity of that game’s portrayal of the painful reality of a dairy cow’s punishing daily existence and untimely end.

  7. Get the right mix of bricks & clicks.

    Science.gov (United States)

    Gulati, R; Garino, J

    2000-01-01

    The bright line that once distinguished the dot-com from the incumbent is rapidly fading. Success in the new economy will go to those who can execute clicks-and-mortar strategies that bridge the physical and virtual worlds. But how executives forge such strategies is under considerable debate. Despite the obvious benefits that integration offers--cross-promotion, shared information, purchasing leverage, distribution economies, and the like--many executives now assume that Internet businesses have to be separate to thrive. They believe that the very nature of traditional business--its protectiveness of current customers, its fear of cannibalization, its general myopia--will smother any Internet initiative. Authors Ranjay Gulati and Jason Garino contend that executives don't have to make an either- or choice when it comes to their clicks-and-mortar strategies. The question isn't, "Should we develop our Internet channel in-house or launch a spin-off?" but rather, "What degree of integration makes sense for our company?" To determine the best level of integration for their companies, executives should examine four business dimensions: brand, management, operations, and equity. Drawing on the experiences of three established retailers--Office Depot, KB Toys, and Rite Aid--the authors show the spectrum of strategies available and discuss the trade-offs involved in each choice. By thinking carefully about which aspects of a business to integrate and which to keep distinct, companies can tailor their clicks-and-mortar strategy to their own particular market and competitive situation, dramatically increasing their odds of e-business success. PMID:11183973

  8. Medclic: the Mediterranean in one click

    Science.gov (United States)

    Troupin, Charles; Frontera, Biel; Sebastián, Kristian; Pau Beltran, Joan; Krietemeyer, Andreas; Gómara, Sonia; Gomila, Mikel; Escudier, Romain; Juza, Mélanie; Mourre, Baptiste; Garau, Angels; Cañellas, Tomeu; Tintoré, Joaquín

    2016-04-01

    "Medclic: the Mediterranean in one click" is a research and dissemination project focused on the scientific, technological and societal approaches of the Balearic Islands Coastal Observing and Forecasting System ({SOCIB}{www.socib.es}) in a collaboration with "la Caixa" Foundation. SOCIB aims at research excellence and the development of technology which enables progress toward the sustainable management of coastal and marine environments, providing solutions to meet the needs of society. Medclic goes one step forward and has two main goals: at the scientific level, to advance in establishing and understanding the mesoscale variability at the regional scale and its interaction, and thus improving the characterisation of the "oceanic weather" in the Mediterranean; at the outreach level: to bring SOCIB and the new paradigm of multi-platform observation in real time closer to society, through scientific outreach. SOCIB Data Centre is the core of the new multi-platform and real time oceanography and is responsible for directing the different stages of data management, ranging from data acquisition to its distribution and visualization through web applications. The system implemented relies on open source solutions and provides data in line with international standards and conventions (INSPIRE, netCDF Climate and Forecast, ldots). In addition, the Data Centre has implemented a REST web service, called Data Discovery. This service allows data generated by SOCIB to be integrated into applications developed by the Data Centre itself or by third parties, as it is the case with Medclic. Relying on this data distribution, the new web Medclic, www.medclic.es, constitutes an interactive scientific and educational area of communication that contributes to the rapprochement of the general public with the new marine and coastal observing technologies. Thanks to the Medclic web, data coming from new observing technologies in oceanography are available in real time and in one clic

  9. Canadians' level of confidence in their sources of nutrition information.

    Science.gov (United States)

    Marquis, Marie; Dubeau, Caroline; Thibault, Isabelle

    2005-01-01

    North Americans have a great interest in health and nutrition. However, because sources of nutrition information are vast, the quality of the information varies. We explored the potential benefit of segmenting the Canadian population by geographical location and age in determining the principal sources of nutrition information and level of confidence in these sources. A survey was posted on the Dietitians of Canada website: subjects indicated how frequently they used different healthy eating sources and their level of confidence in the various sources. A total of 870 questionnaires were retained. Magazines, books, the Internet, food labels, and brochures were the most frequently used sources of information. Analyses indicated differences between geographic areas in the use of the media (radio, newspaper, television), dietitians, and naturopaths as sources of nutrition information (pconfident about nutrition information received from dietitians, physicians, books, the government, and nurses, with some differences occurring between geographic areas (p<0.05). PMID:16159410

  10. Five-level Z-source diode-clamped inverter

    DEFF Research Database (Denmark)

    Gao, F.; Loh, Poh Chiang; Blaabjerg, Frede;

    2010-01-01

    This study proposes a five-level Z-source diode-clamped inverter designed with two intermediate Z-source networks connected between the dc input sources and rear-end inverter circuitry. By partially shorting the Z-source networks, new operating states not previously reported for two-level Z...... scheme, which always inserts two partial shoot-through states per half carrier cycle for smooth balanced operation. Theoretical findings and practical issues identified are eventually verified by constructing a scaled down laboratory prototype for testing....

  11. Words are Silver, Mouse-Clicks are Gold? (or how to optimize the level of language formalization of young students in a Logo-based cubics world

    Directory of Open Access Journals (Sweden)

    Evgenia SENDOVA

    2007-10-01

    Full Text Available How do we teach children to express and communicate ideas in a formal and informal mode? What type of language do they need in a concrete context? How should they determine a proper level of formalization of their descriptions? In an attempt to explore these issues we carried out a pilot experiment in the frames of the DALEST European project whose goal was to create environment for stimulating the 3D geometry understanding of young students and to assist them in developing some fundamental mathematical skills including spatial visualization and articulating ideas. The pilot experiment was carried out with 5th graders from five Bulgarian schools by means of specially designed educational scenarios and the Cubix Editor (a Logo based application for manipulating unit-sized cubes. The children were given tasks to describe compositions of unit-sized cubes and to build such compositions by means of the Cubix Editor when given their descriptions by peers. The students experienced the whole process of generating a good description - becoming aware of the ambiguity, producing counterexamples, reducing the ambiguity, eliminating the redundancy. The pilot experiment aimed at specifying the structure, scope and methods behind the stereometry activities envisaged for 5th graders in the frames of the DALEST project. The first impressions confirm our belief that the language is playing significant role in the learning experiences of the students, that the relationship between thoughts and words involves back and forth reshaping process. While constructing and describing cubical structures they articulated their own ideas, developed concepts collaboratively with others, moved between everyday and mathematical terms, between procedural and declarative style, exploring the boundaries of understanding. Such interplay with the step-wise refinement of their descriptions of cubical structures would hopefully enhance students' skills for working with mathematical

  12. Global Sourcing: Evidence from Spanish Firm-level Data

    DEFF Research Database (Denmark)

    Kohler, Wilhelm; Smolka, Marcel

    2012-01-01

    We investigate the link between productivity of firms and their sourcing behavior. Following Antràs and Helpman (2004) we distinguish between domestic and foreign sourcing, as well as between outsourcing and vertical integration. A firm's choice is driven by a hold-up problem caused by lack of...... enforceable contracts. We use Spanish firm-level data to examine the productivity premia associated with the different sourcing strategies....

  13. Characterisation of a protection level 241Am calibration source

    International Nuclear Information System (INIS)

    A 241Am radioactive source and transport mechanism was installed at the National Physical Laboratory in December 1991 to be used for protection level calibration work. This report details the various measurements involved in the commissioning process. (Author)

  14. Click.

    Science.gov (United States)

    2016-05-01

    The under-18 conception rate in the UK for 2013 is the lowest since 1969. Despite this, the UK remains among the top five in the EU in terms of live births to women aged 15-17 and 15-19, and reducing teenage pregnancy is high on the government agenda. The following websites offer advice on sex and relationships for children and young people. PMID:27156412

  15. Sources and levels of radioactivity in the Philippine environment

    International Nuclear Information System (INIS)

    Over the years, the Health Physics Research Section has assessed the sources and levels of radiation exposure in the Philippine environment. The data show that although Filipinos are exposed to both natural and artificial sources of environmental radioactivity, natural sources contribute much more significantly to the dose received by Filipinos than artificial sources. The average equivalent dose rate due to external sources of natural radiation in the Philippines is 45 μSv h-1. Of this total dose rate, an average of 22 μSv h-1 is due to cosmic radiation while an average of 23 μSv h-1 is due to terrestrial radiation. External sources of natural radiation in the Philippines thus account for an annual per caput effective dose of about 400 μSv. In contrast, the annual per caput dose due to an artificial source, i.e., nuclear power production, was estimated by UNSCEAR (1988) to be only 0.6 μSv. Based on levels of background radioactivity due to external sources of natural radiation which were measured in 1600 locations, a radiation map of the country was developed. Among the internal sources of natural radiation, radon is the large contributor to dose and is considered as a serious indoor pollutant. Indoor radon levels in about 400 Filipino houses ranged from 1 to 63 Bq m-3 with a mean of 24 Bq m-3. Significantly higher levels ranging from 30 to 347 Bq m-3 were observed in underground, non-uranium mines. Since there are no operational nuclear power plant in the Philippines, artificial radionuclides in the environment consist mainly of long-lived 137Cs and 90Sr from atmospheric nuclear weapons tests

  16. One Click: The CECS Students’ Assistant Tools

    Directory of Open Access Journals (Sweden)

    FROILAN G. DESTREZA

    2014-02-01

    Full Text Available This study is pursued because the researchers believe that the design project is more convenient to use in a group discussion as students are expected to gain more knowledge during peer to peer discussion. Through this study, some issues in the traditional way of teaching will be resolve like the time-consuming checking of attendance, quizzes dictation, paying of test papers and the fear of students to participate in recitation The researchers used Prototyping model as procedural method for the successful development and implementation of the hardware and software. This method has five phases which include: quick plan, quick design, prototype construction, delivery and feedback and communication. This study was evaluated by the CECS Students and the assessment of the respondent regarding the software and hardware application was measured in different levels of acceptability such as Accuracy, Adaptability, Effectiveness, Efficiency, Interactive, Portability, Reliability, Security and User-friendliness. The overall acceptability of the traditional way of teaching as evaluated by the respondents is satisfactory. With regard to the evaluation of One Click: The CECS Students’ Assistant Tool, the overall acceptability is excellent. Through evaluation, the researchers had determined that there is a significant difference between the levels of acceptability of the traditional way of teaching and the “One Click: The CECS Students’ Assistant Tool” in terms of the given set of criteria. The recommendation of the researchers in the design project are as follows: enhance the system where the users/students can go back and answer the previous questions and add an interface where user/instructor can delete files.

  17. Z - Source Multi Level Inverter Based PV Generation System

    Directory of Open Access Journals (Sweden)

    T. Lakhmi kanth

    2014-09-01

    Full Text Available In this paper a novel technique of Z-Source multilevel Inverter based PV Generation system is implemented and simulated using MATLAB-Simulink simulation software. The Photovoltaic cells are healthier option for converting solar energy into electricity. Due to high capital cost and low efficiency PV cells have not yet been a fully smart choice for electricity users. To enhance the performance of the system, Z-Source multi level inverter can be used in place of conventional Voltage Source Inverter (VSI in Solar Power Generation System. The PV cell model is developed using circuit mathematical equations. The Z-Source multilevel inverter is modeled to realize boosted DC to AC conversion (inversion with low THD. Outcome shows that the energy conversion efficiency of ZSMLI is a lot improved as compared to conventional voltage Source Inverter (VSI. By doing FFT analysis we can know the total THD.

  18. Noise Sources and Levels in Intensive Care Units

    Directory of Open Access Journals (Sweden)

    Emine Kol

    2015-12-01

    Full Text Available Objective: Noise has been an important problem for both patients and healthcare workers at hospitals. The study was aimed at determining noise sources and noise levels intensive care units. Material and Method: Noise level measurements were performed in four weeks between March 01, 2012 and April 01, 2012. Noise measurement was performed using a Extech 407780 sound level meter during 24 hours. At the same time, observation was performed to identify the sound sources and the highest noise sources were noted by researcher. The sound level meter was placed on the wall between two patient beds and the nurses’ station. Results: The sources of the highest noises were the conversation voices coming from the nurses’ station (84.1 dB(A and perfusor alarm (83.2 dB(A. Other sources of noise were the alarm sounds from the pulse oximetry (81.1 dB(A, nebulizator (80.1 dB(A, monitor (78.6 dB(A, ringing phones (77.4 dB(A, infusion pump (76 dB(A and ventilator (75 dB(A. Conclusion: Staff conversations, caring activities and monitor alarm management are controlled by health Professionals. Therefore, it is particularly important in informing nurses about noise control.

  19. Heat Pump with Two Heat Sources on Different Temperature Levels

    OpenAIRE

    Bertsch, Stefan; Uhlmann, Michael; Heldstab, Andres

    2014-01-01

    Aim of the project is the development of a new heat pump system with economizing that is able to improve the heating performance using two or more different heat sources. These heat sources preferably on different temperature levels are incorporated in the system with minimal loss of exergy, by adding the heat at different pressure levels. Applications are i.e. buildings with heat pump and a solar thermal collector. While solar thermal systems can be used for heating and domestic hot water in...

  20. Offshore Dredger Sounds: Source Levels, Sound Maps, and Risk Assessment.

    Science.gov (United States)

    de Jong, Christ A F; Ainslie, Michael A; Heinis, Floor; Janmaat, Jeroen

    2016-01-01

    The underwater sound produced during construction of the Port of Rotterdam harbor extension (Maasvlakte 2) was measured, with emphasis on the contribution of the trailing suction hopper dredgers during their various activities: dredging, transport, and discharge of sediment. Measured source levels of the dredgers, estimated source levels of other shipping, and time-dependent position data from a vessel-tracking system were used as input for a propagation model to generate dynamic sound maps. Various scenarios were studied to assess the risk of possible effects of the sound from dredging activities on marine fauna, specifically on porpoises, seals, and fish. PMID:26610959

  1. Preparing polymeric biomaterials using "click" chemistry techniques

    Science.gov (United States)

    Lin, Fei

    Significant efforts have been focused on preparing degradable polymeric biomaterials with controllable properties, which have the potential to stimulate specific cellular responses at the molecular level. Click reactions provide a universal tool box to achieve that goal through molecular level design and modification. This dissertation demonstrates multiple methodologies and techniques to develop advanced biomaterials through combining degradable polymers and click chemistry. In my initial work, a novel class of amino acid-based poly(ester urea)s (PEU) materials was designed and prepared for potential applications in bone defect treatment. PEUs were synthesized via interfacial polycondensation, and showed degradability in vivo and possessed mechanical strength superior to conventionally used polyesters. Further mechanical enhancement was achieved after covalent crosslinking with a short peptide crosslinker derived from osteogenic growth peptide (OGP). The in vitro and in an in vivo subcutaneous rat model demonstrated that the OGP-based crosslinkers promoted proliferative activity of cells and accelerated degradation properties of PEUs. As a continuous study, extra efforts were focused on the development of PEUs with functional pendant groups, including alkyne, azide, alkene, tyrosine phenol, and ketone groups. PEUs with Mw exceeding to 100K Da were obtained via interfacial polycondensation, and the concentration of pendent groups was varied using a copolymerization strategy. Electrospinning was used to fabricate PEU nanofiber matrices with mechanical strengths suitable for tissue engineering. A series of biomolecules were conjugated to nanofiber surface following electrospinning using click reactions in aqueous media. The ability to derivatize PEUs with biological motifs using high efficient chemical reactions will significantly expand their use in vitro and in vivo. Based on similar principles, a series of mono- and multifunctionalized polycaprolactone (PCL

  2. Gamma radiation levels from a line source of monazite

    International Nuclear Information System (INIS)

    Monazite contains some 6% thorium and the thorium decay chain gives rise to gamma radiation emissions. It is often desirable to predict the gamma radiation levels associated with the radioactive decay of the thorium chain in monazite, particularly in situations where storage and transport are involved . The mathematics associated with a radioactive line source are considered and an expression is derived for the prediction of gamma radiation levels from the line source. This is applied to practical situations involving monazite and a mathematical model specifically for monazite is developed. As monazite is transported in bulk bags which are placed inside transport containers, beyond a certain distance from such containers or similar storage devices, the monazite may be considered to approximate a line source. The validity of approximating monazite containers to a line source is checked by comparing the gamma levels predicted by the model with those actually measured in a field situation where transport containers of monazite are involved. 2 refs., 3 figs., 2 tabs

  3. Clicking in a killer whale habitat: narrow-band, high-frequency biosonar clicks of harbour porpoise (Phocoena phocoena and Dall's porpoise (Phocoenoides dalli.

    Directory of Open Access Journals (Sweden)

    Line A Kyhn

    Full Text Available Odontocetes produce a range of different echolocation clicks but four groups in different families have converged on producing the same stereotyped narrow band high frequency (NBHF click. In microchiropteran bats, sympatric species have evolved the use of different acoustic niches and subtly different echolocation signals to avoid competition among species. In this study, we examined whether similar adaptations are at play among sympatric porpoise species that use NBHF echolocation clicks. We used a six-element hydrophone array to record harbour and Dall's porpoises in British Columbia (BC, Canada, and harbour porpoises in Denmark. The click source properties of all porpoise groups were remarkably similar and had an average directivity index of 25 dB. Yet there was a small, but consistent and significant 4 kHz difference in centroid frequency between sympatric Dall's (137±3 kHz and Canadian harbour porpoises (141±2 kHz. Danish harbour porpoise clicks (136±3 kHz were more similar to Dall's porpoise than to their conspecifics in Canada. We suggest that the spectral differences in echolocation clicks between the sympatric porpoises are consistent with evolution of a prezygotic isolating barrier (i.e., character displacement to avoid hybridization of sympatric species. In practical terms, these spectral differences have immediate application to passive acoustic monitoring.

  4. Protocol of source shielding maintenance in a level measurement systems

    International Nuclear Information System (INIS)

    Maintenance labor of the source shielding and locking system is not performed in many Venezuelan enterprises that employ radioactive level gauge in large container. The lack of maintenance and the ambient long lasting action have produced impairment of many devices and their given parts rise to economical and radiological protection problems. In order to help to solve the mentioned problems, principally to reduce the unjustified dose to workers, the IVIC Health Physics Service worked out a protocol to perform, in a safety way, the maintenance of source shielding and its locking system. This protocol is presented in this paper. (authors)

  5. Evaluating forensic biology results given source level propositions.

    Science.gov (United States)

    Taylor, Duncan; Abarno, Damien; Hicks, Tacha; Champod, Christophe

    2016-03-01

    The evaluation of forensic evidence can occur at any level within the hierarchy of propositions depending on the question being asked and the amount and type of information that is taken into account within the evaluation. Commonly DNA evidence is reported given propositions that deal with the sub-source level in the hierarchy, which deals only with the possibility that a nominated individual is a source of DNA in a trace (or contributor to the DNA in the case of a mixed DNA trace). We explore the use of information obtained from examinations, presumptive and discriminating tests for body fluids, DNA concentrations and some case circumstances within a Bayesian network in order to provide assistance to the Courts that have to consider propositions at source level. We use a scenario in which the presence of blood is of interest as an exemplar and consider how DNA profiling results and the potential for laboratory error can be taken into account. We finish with examples of how the results of these reports could be presented in court using either numerical values or verbal descriptions of the results. PMID:26720813

  6. Source Similarity and Social Media Health Messages: Extending Construal Level Theory to Message Sources.

    Science.gov (United States)

    Young, Rachel

    2015-09-01

    Social media users post messages about health goals and behaviors to online social networks. Compared with more traditional sources of health communication such as physicians or health journalists, peer sources are likely to be perceived as more socially close or similar, which influences how messages are processed. This experimental study uses construal level theory of psychological distance to predict how mediated health messages from peers influence health-related cognition and behavioral intention. Participants were exposed to source cues that identified peer sources as being either highly attitudinally and demographically similar to or different from participants. As predicted by construal level theory, participants who perceived sources of social media health messages as highly similar listed a greater proportion of beliefs about the feasibility of health behaviors and a greater proportion of negative beliefs, while participants who perceived sources as more dissimilar listed a greater proportion of positive beliefs about the health behaviors. Results of the study could be useful in determining how health messages from peers could encourage individuals to set realistic health goals. PMID:26348816

  7. Flexible Piezoelectric Energy Harvesting from Mouse Click Motions

    Directory of Open Access Journals (Sweden)

    Youngsu Cha

    2016-07-01

    Full Text Available In this paper, we study energy harvesting from the mouse click motions of a robot finger and a human index finger using a piezoelectric material. The feasibility of energy harvesting from mouse click motions is experimentally and theoretically assessed. The fingers wear a glove with a pocket for including the piezoelectric material. We model the energy harvesting system through the inverse kinematic framework of parallel joints in a finger and the electromechanical coupling equations of the piezoelectric material. The model is validated through energy harvesting experiments in the robot and human fingers with the systematically varying load resistance. We find that energy harvesting is maximized at the matched load resistance to the impedance of the piezoelectric material, and the harvested energy level is tens of nJ.

  8. Flexible Piezoelectric Energy Harvesting from Mouse Click Motions.

    Science.gov (United States)

    Cha, Youngsu; Hong, Jin; Lee, Jaemin; Park, Jung-Min; Kim, Keehoon

    2016-01-01

    In this paper, we study energy harvesting from the mouse click motions of a robot finger and a human index finger using a piezoelectric material. The feasibility of energy harvesting from mouse click motions is experimentally and theoretically assessed. The fingers wear a glove with a pocket for including the piezoelectric material. We model the energy harvesting system through the inverse kinematic framework of parallel joints in a finger and the electromechanical coupling equations of the piezoelectric material. The model is validated through energy harvesting experiments in the robot and human fingers with the systematically varying load resistance. We find that energy harvesting is maximized at the matched load resistance to the impedance of the piezoelectric material, and the harvested energy level is tens of nJ. PMID:27399705

  9. Flexible Piezoelectric Energy Harvesting from Mouse Click Motions

    Science.gov (United States)

    Cha, Youngsu; Hong, Jin; Lee, Jaemin; Park, Jung-Min; Kim, Keehoon

    2016-01-01

    In this paper, we study energy harvesting from the mouse click motions of a robot finger and a human index finger using a piezoelectric material. The feasibility of energy harvesting from mouse click motions is experimentally and theoretically assessed. The fingers wear a glove with a pocket for including the piezoelectric material. We model the energy harvesting system through the inverse kinematic framework of parallel joints in a finger and the electromechanical coupling equations of the piezoelectric material. The model is validated through energy harvesting experiments in the robot and human fingers with the systematically varying load resistance. We find that energy harvesting is maximized at the matched load resistance to the impedance of the piezoelectric material, and the harvested energy level is tens of nJ. PMID:27399705

  10. Radiation efficiency of earthquake sources at different hierarchical levels

    Energy Technology Data Exchange (ETDEWEB)

    Kocharyan, G. G., E-mail: gevorgkidg@mail.ru [Institute of Dynamics of Geospheres RAS, Moscow, 119334 (Russian Federation); Moscow Institute of Physics and Technology (State University), Dolgoprudny, 117303 (Russian Federation)

    2015-10-27

    Such factors as earthquake size and its mechanism define common trends in alteration of radiation efficiency. The macroscopic parameter that controls the efficiency of a seismic source is stiffness of fault or fracture. The regularities of this parameter alteration with scale define several hierarchical levels, within which earthquake characteristics obey different laws. Small variations of physical and mechanical properties of the fault principal slip zone can lead to dramatic differences both in the amplitude of released stress and in the amount of radiated energy.

  11. Radiation efficiency of earthquake sources at different hierarchical levels

    International Nuclear Information System (INIS)

    Such factors as earthquake size and its mechanism define common trends in alteration of radiation efficiency. The macroscopic parameter that controls the efficiency of a seismic source is stiffness of fault or fracture. The regularities of this parameter alteration with scale define several hierarchical levels, within which earthquake characteristics obey different laws. Small variations of physical and mechanical properties of the fault principal slip zone can lead to dramatic differences both in the amplitude of released stress and in the amount of radiated energy

  12. Nanoparticles under the light: click functionalization by photochemical thiol-yne reaction, towards double click functionalization.

    Science.gov (United States)

    Demay-Drouhard, Paul; Nehlig, Emilie; Hardouin, Julie; Motte, Laurence; Guénin, Erwann

    2013-06-24

    A light click away: The first application of the thiol-yne reaction to nanoparticle functionalization is described (see figure). This metal-free click chemistry approach is compatible with the addition of various molecules at the surface and can be combined with CuAAC methodology to perform chemoselective double functionalization. PMID:23744751

  13. MRI Findings in Patients with TMJ Click

    Directory of Open Access Journals (Sweden)

    Mahrokh Imanimoghaddam

    2013-12-01

    Full Text Available Introduction: It has been shown that joint click, an initial and common finding in internal derangement (ID, respond to neither conservative treatment nor surgical intervention. This raises the question as to whether it must be treated in the absence of other pertinent signs and symptoms, so the aim of this study was to investigate and compare the MRI findings of TMJ in both normal subjects and patients with click, in order to determine the importance of click in predicting TMJ pathological changes. Methods: A total of 26 patients with clinical symptoms of disk displacement with reduction (DDwR according to RDC/TMD were compared to 14 normal subjects in terms of their MRI findings, including disk displacement, effusion, condylar osteoarthritic changes and disk deformities. Results: Out of 80 joints in total (52 affected joints in 26 patients and 28 joints in control group, 48 were shown with normal disk position in MRI whereas 28 (35% and 4 (5% were categorised as DDwR and (disk displacement without reduction DDwoR, respectively. Statistically significant correlations were established between the following pairs of variables in order: Click and disk displacement, effusion and disk displacement, disk displacement and effusion with disk deformity. Conclusion: The correlation between the presence of click and disk displacement, disk deformity and effusion emphasizes the importance of MRI for an accurate diagnosis and development of an appropriate treatment plan in these cases and shows that clinical examination is not sufficient for these purposes.

  14. Facile design of biomaterials by 'click' chemistry

    DEFF Research Database (Denmark)

    Hvilsted, Søren

    2012-01-01

    chemistry is elaborated. The present state of creating functional and biologically active surfaces by click chemistry is presented. Finally, conducting surfaces based on an azide‐functionalized polymer with prospective biological sensor potential are introduced. Copyright © 2012 Society of Chemical Industry......The advent of the so‐called ‘click chemistry’ a decade ago has significantly improved the chemical toolbox for producing novel biomaterials. This review focuses primarily on the application of Cu(I)‐catalysed azide–alkyne 1,3‐cycloadditon in the preparation of numerous, diverse biomaterials and...

  15. Modelling the NO emissions from wildfires at the source level

    Science.gov (United States)

    Pérez-Ramirez, Y.; Santoni, P.-A.; Darabiha, N.

    2014-05-01

    There is a growing interest to characterize fire plumes in order to control air quality during wildfire episodes and to estimate the carbon and ozone balance of fire emissions. A numerical approach has been used to study the mechanisms of NO formation at the source level in wildfires given that NO plays an important role in the formation of ground-level ozone. The major reaction mechanisms involved in NO chemistry have been identified using reaction path analysis. Accordingly, a two-step global kinetic scheme in the gas phase has been proposed herein to account for the volatile fuel-bound nitrogen (fuel-N) conversion to NO, considering that the volatile fraction of fuel-N is released as NH3. Data from simulations using the perfectly stirred reactor (PSR) code from CHEMKIN-II package with a detailed kinetic mechanism (GDF-Kin® 3.0) have been used to calibrate and evaluate the global model under typical wildfire conditions in terms of the composition of the degradation gases of vegetation, the equivalence ratio, the range of temperatures and the residence time.

  16. Modelling the NO emissions from wildfires at the source level

    Directory of Open Access Journals (Sweden)

    Y. Pérez-Ramirez

    2013-12-01

    Full Text Available There is a growing interest to characterize fire plumes in order to control air quality during wildfire episodes and to estimate the carbon and ozone balance of fire emissions. A numerical approach has been used to study the mechanisms of NO formation at the source level in wildfires given that NO plays an important role on the formation of ground-level ozone. The major reaction mechanisms involved in NO chemistry have been identified using reactions path analysis. Accordingly, a two-step global kinetic scheme in the gas phase has been proposed herein to account for the volatile fuel-bound nitrogen (fuel-N conversion to NO, considering that the volatile fraction of fuel-N is released as NH3. Data from simulations using the PSR code from CHEMKIN-II package with a detailed kinetic mechanism (GDF-kin® 3.0 have been used to calibrate and evaluate the global model under typical wildfire conditions in terms of the composition of the degradation gases of vegetation, the equivalence ratio, the range of temperatures and the residence time.

  17. Computer Security: one click and BOOM…

    CERN Multimedia

    Stefan Lueders, Computer Security Team

    2016-01-01

    Browsing the World Wide Web is not as easy as it seems… One wrong click and all your passwords (CERN, Facebook, PayPal, Amazon, etc.) could be stolen; all your activities could be clandestinely monitored (mouse movements and clicks, words typed, screenshots, microphone and webcam recordings, etc.); confidential documents could be stolen; and an attack path (a so-called back-door) into CERN could be opened…    As a result, you would have to reinstall your computer from scratch and change all your passwords! One of our colleagues learned this the hard way. One wrong click in summer 2015 permitted malicious attackers to infiltrate CERN but, fortunately, no real damage was done. Still, the cost of investigating the incident ran to several tens of thousands of Swiss francs and a lot of time was wasted trying to understand the attacker’s intent and the extent of the infiltration... With the goal of increasing more awareness of the risk of clicking on li...

  18. Influence of the season on vitamin D levels and regulatory T cells in patients with polymorphic light eruption† †Electronic supplementary information (ESI) available. See DOI: 10.1039/c5pp00398a Click here for additional data file. Click here for additional data file.

    Science.gov (United States)

    Schweintzger, N. A.; Gruber-Wackernagel, A.; Shirsath, N.; Quehenberger, F.; Obermayer-Pietsch, B.

    2016-01-01

    The exact mechanisms of photohardening in polymorphic light eruption (PLE) are still unknown, but medical photohardening was shown to increase regulatory T cell (Treg) numbers in the blood of PLE patients, similar to natural hardening. Furthermore, oral vitamin D supplementation increased peripheral Tregs in healthy individuals. We herein report on a post hoc analysis of 26 screened PLE patients of a clinical trial (ClinicalTrials.gov No. NCT01595893), in which the influence of the progressing season was investigated on baseline CD4+CD25+FoxP3+CD127– Treg numbers by flow cytometry and Treg suppressive function by co-culture assays with T effector cells as a secondary endpoint, together with 25-hydroxy vitamin D (25(OH)D) serum levels at the study's screening visit, taking place in the period from January to June. The mean 25(OH)D serum level of all patients was 33.2 ng ml–1. Ten of those patients (38.5%) were identified with low 25(OH)D levels (<30 ng ml–1). Significantly higher baseline 25(OH)D serum levels (plus 34.4%; P = 0.0182) as well as higher relative Treg percentages in CD4+ population (plus 62.8%; P = 0.0157) and in total lymphocyte population (plus 59.6%; P = 0.0372) and higher absolute Treg numbers (plus 100.2%; P = 0.0042) were observed in the late spring/early summer period (April to June) compared to the winter period (January to February). No significant relationship was observed when Treg numbers and function were correlated with 25(OH)D levels. These data indicate that in PLE patients Treg numbers and their suppressive function are independent of vitamin D serum levels and suggest that UV light and/or other seasonal factors may affect these cells via the non-vitamin D related pathway(s). PMID:26911519

  19. User's Manual for the SOURCE1 and SOURCE2 Computer Codes: Models for Evaluating Low-Level Radioactive Waste Disposal Facility Source Terms (Version 2.0)

    International Nuclear Information System (INIS)

    The SOURCE1 and SOURCE2 computer codes calculate source terms (i.e. radionuclide release rates) for performance assessments of low-level radioactive waste (LLW) disposal facilities. SOURCE1 is used to simulate radionuclide releases from tumulus-type facilities. SOURCE2 is used to simulate releases from silo-, well-, well-in-silo-, and trench-type disposal facilities. The SOURCE codes (a) simulate the degradation of engineered barriers and (b) provide an estimate of the source term for LLW disposal facilities. This manual summarizes the major changes that have been effected since the codes were originally developed

  20. Syntheses of Sulfo-Glycodendrimers Using Click Chemistry and Their Biological Evaluation

    Directory of Open Access Journals (Sweden)

    Tomohiro Fukuda

    2012-10-01

    Full Text Available A series of novel glycol-clusters containing sulfonated N-acetyl-D-glucosamine (GlcNAc have been synthesized using click chemistry. Three dendrimers with aromatic dendrons were synthesized using chlorination, azidation and click chemistries. The resulting dendrimers were modified with azide-terminated sulfonated GlcNAc using click chemistry. The sulfonated dendrimers showed affinity for proteins, including the lectin wheat germ agglutinin and amyloid beta peptide (1-42. The dendrimers of G1 and G2 in particular showed the largest affinity for the proteins. The addition of the sulfonated GlcNAc dendrimers of G1 and G2 exhibited an inhibition effect on the aggregation of the amyloid beta peptide, reduced the b-sheet conformation, and led to a reduction in the level of nanofiber formation.

  1. Click and click-type chemistries in castor and sunflower oil-based monomers and polymers

    OpenAIRE

    Lluch Porres, Cristina

    2013-01-01

    El desenvolupament de materials polimèrics a partir de fonts renovables està rebent un interès creixent degut a la incertesa en el preu i les reserves d’olis i a aspectes mediambientals. A més a més, maximitzar els beneficis d’emprar fonts renovables requereix l’aplicació de metodologies químiques altament sostenibles i eficients, exemplificades per les reacciones Click o tipus Click. D’altra banda, el disseny de polímers funcionalitzats amb propietats modulables i per tant, amb una aplica...

  2. Nine Level Inverter with Boost Converter from Renewable Energy Source

    Directory of Open Access Journals (Sweden)

    Maruthu Pandiyan.R

    2015-01-01

    Full Text Available A new single phase nine level multilevel inverter is proposed. The input to the proposed nine level multilevel inverter is obtained from solar panel . The solar energy obtained from the solar panel is not constant and it varies with times. In order to maintain the constant voltage obtained from the solar panel the boost converter is used to maintain the constant output voltage using MPPT ( Perturb and observe algorithm algorithm. Then the buck boost converter output voltage is stored in the battery bank. Finally the battery energy is connected to the 9 level inverter circuits. The harmonics in the inverter is eliminated by using the fuzzy logic controller. The gate pulse for the multilevel inverter is given by the fuzzy logic controller which in turn reduces the harmonics in the inverter. Then the inverter output is connected to the grid are some application.

  3. Uranium recovery from low-level aqueous sources

    International Nuclear Information System (INIS)

    The aqueous sources of soluble uranium were surveyed and evaluated in terms of the uranium geochemical cycle in an effort to identify potential unexploited resources. Freshwater sources appeared to be too low in uranium content to merit consideration, while seawater, although very dilute (approx. 3.3 ppB), contains approx. 4 x 109 metric tons of uranium in all the world's oceans. A literature review of recent publications and patents concerning uranium recovery from seawater was conducted. Considerable experimental work is currently under way in Japan; less is being done in the European countries. An assessment of the current state of technology is presented in this report. Repeated screening programs have identified hydrous titanium oxide as the most promising candidate absorbent. However, some of its properties such as distribution coefficient, selectivity, loading, and possibly stability appear to render its use inadequate in a practical recovery system. Also, various assessments of the energy efficiency of pumped or tidal power schemes for contacting the sorbent and seawater are in major disagreement. Needed future research and development tasks are discussed. A fundamental sorbent development program to greatly improve sorbent properties would be required to permit practical recovery of uranium from seawater. Major unresolved engineering aspects of such recovery systems are also identified and discussed

  4. Thiol click modification of cyclic disulfide containing biodegradable polyurethane urea elastomers.

    Science.gov (United States)

    Fang, Jun; Ye, Sang-Ho; Wang, Jing; Zhao, Ting; Mo, Xiumei; Wagner, William R

    2015-05-11

    Although the thiol click reaction is an attractive tool for postpolymerization modification of thiolmers, thiol groups are easily oxidized, limiting the potential for covalent immobilization of bioactive molecules. In this study, a series of biodegradable polyurethane elastomers incorporating stable cyclic disulfide groups was developed and characterized. These poly(ester urethane)urea (PEUU-SS) polymers were based on polycaprolactone diol (PCL), oxidized dl-dithiothreitol (O-DTT), lysine diisocyanate (LDI), or butyl diisocyanate (BDI), with chain extension by putrescine. The ratio of O-DTT:PCL was altered to investigate different levels of potential functionalization. PEG acrylate was employed to study the mechanism and availability of both bulk and surface click modification of PEUU-SS polymers. All synthesized PEUU-SS polymers were elastic with breaking strengths of 38-45 MPa, while the PEUU-SS(LDI) polymers were more amorphous, possessing lower moduli and relatively small permanent deformations versus PEUU-SS(BDI) polymers. Variable bulk click modification of PEUU-SS(LDI) polymers was achieved by controlling the amount of reduction reagent, and rapid reaction rates occurred using a one-pot, two-step process. Likewise, surface click reaction could be carried out quickly under mild, aqueous conditions. Furthermore, a maleimide-modified affinity peptide (TPS) was successfully clicked on the surface of an electrospun PEUU-SS(BDI) fibrous sheet, which improved endothelial progenitor cell adhesion versus corresponding unmodified films. The cyclic disulfide containing biodegradable polyurethanes described provide an option for cardiovascular and other soft tissue regenerative medicine applications where a temporary, elastic scaffold with designed biofunctionality from a relatively simple click chemistry approach is desired. PMID:25891476

  5. Determination of the acoustic source power levels of wind turbines

    Science.gov (United States)

    Debruijn, A.; Stam, W. J.; Dewolf, W. B.

    To facilitate Wind Energy Conversin System (WECS) licensing, it is recommended to obtain the immission-relevant sound power from the WECS, since this quantity fits into most recommendations for industrial installations. Measurements on small and medium-scale WECS show that rotor rotation speed is a more important parameter than the wind velocity with regard to the radiated noise. An acoustic telescope was used to identify noise sources on two medium-size wind turbines. The mechanical noise from the nacelle is mostly predominant but the trailing edge aerodynamic noise is not negligible. A prediction model for this type of noise, which leads to good agreement with experimental data was developed. A method to suppress turbulence signals around WECS is a set-up with twin microphones, using correlation techniques on both signals.

  6. Query Representation with Global Consistency on User Click Graph

    OpenAIRE

    Zhang, Daqiang; Zhu, Rongbo; Men, Shuqiqiu; Raychoudhury, Vaskar

    2013-01-01

    Extensive research has been conducted on query log analysis. A query log is generally represented as a bipartite graph on a query set and a URL set. Most of the traditional methods used the raw click frequency to weigh the link between a query and a URL on the click graph. In order to address the disadvantages of raw click frequency, researchers proposed the entropy-biased model, which incorporates raw click frequency with inverse query frequency of the URL as the weighting scheme for query r...

  7. Five-Level Z-Source Neutral Point-Clamped Inverter

    DEFF Research Database (Denmark)

    Gao, F.; Loh, P.C.; Blaabjerg, Frede;

    2007-01-01

    This paper proposes a five-level Z-source neutralpoint- clamped (NPC) inverter with two Z-source networks functioning as intermediate energy storages coupled between dc sources and NPC inverter circuitry. Analyzing the operational principles of Z-source network with partial dclink shoot......-through scheme reveals the hidden theories in the five-level Z-source NPC inverter unlike the operational principle appeared in the general two-level Z-source inverter, so that the five-level Z-source NPC inverter can be designed with the modulation of carrier-based phase disposition (PD) or alternative phase...... opposite disposition (APOD) technique. To verify the theoretical findings and practical issues, a scaled down laboratory prototype was constructed and tested with a 1.3 kw induction motor load....

  8. Determination of activation level energy of nuclear isomers by calibration of microspectra of radioactive sources

    International Nuclear Information System (INIS)

    Nuclear isomers with unknown activation level were irradiated by calibrated radioactive sources. The integral cross sections were calculated for different energies of the sources. The activation energy was given by values coinciding with each other within the limits of error. The method made the determination of the unknown level of 1180+-10 keV of 195Pt nucleus possible. (author)

  9. Complex Surface Concentration Gradients by Stenciled "Electro Click Chemistry"

    DEFF Research Database (Denmark)

    Hansen, Thomas Steen; Lind, Johan Ulrik; Daugaard, Anders Egede;

    2010-01-01

    Complex one- or two-dimensional concentration gradients of alkynated molecules are produced on azidized conducting polymer substrates by stenciled "electro click chemistry". The latter describes the local electrochemical generation of catalytically active Cu(I) required to complete a "click...

  10. Comparative analysis of clicks and judgments for IR evaluation

    NARCIS (Netherlands)

    J. Kamps; M. Koolen; A. Trotman

    2009-01-01

    Queries and click-through data taken from search engine transaction logs is an attractive alternative to traditional test collections, due to its volume and the direct relation to end-user querying. The overall aim of this paper is to answer the question: How does click-through data differ from expl

  11. Modulation Schemes of Multi-phase Three-Level Z-Source Inverters

    DEFF Research Database (Denmark)

    Gao, F.; Loh, P.C.; Blaabjerg, Frede; Teodorescu, Remus

    This paper investigates the modulation schemes of three-level multiphase Z-source inverters with either two Z-source networks or single Z-source network connected between the dc sources and inverter circuitry. With the proper offset added for achieving both desired four-leg operation and optimized...... with minimal commutation count. Lastly, the theoretical findings are verified in Matlab/PLECS simulation and experimentally using constructed laboratory prototypes....

  12. Conductive Polymer Functionalization by Click Chemistry

    DEFF Research Database (Denmark)

    Daugaard, Anders Egede; Hvilsted, Søren; Hansen, Thomas Steen;

    2008-01-01

    Click chemistry is used to obtain new conductive polymer films based on poly(3,4-ethylenedioxythiophene) (PEDOT) from a new azide functional monomer. Postpolymerization, 1,3-dipolar cycloadditions in DMF, using a catalyst system of CUS04 and sodium ascorbate, and different alkynes are performed to...... functionalize films of PEDOT-N3 and copolymers prepared from EDOT-N3 and 3,4-ethylenedioxythiophene (EDOT). This approach enables new functionalities on PEDOT that could otherwise not withstand the polymerization conditions. Reactions on the thin polymer films have been optimized using an alkynated fluorophore......, with reaction times of '"'-'20 h. The applicability of the method is illustrated by coupling of two other alkynes: a short chain fluorocarbon and a MPEG 5000 to the conductive polymer; this alters the advancing water contact angle of the surface by +20° and -20°/-25°, respectively. The targeted...

  13. A Novel Loom of Click Chemistry in Drug Discovery

    Directory of Open Access Journals (Sweden)

    Shweta Verma

    2015-11-01

    Full Text Available Click chemistry is an interesting and novel approach for drug discovery, material science, bioconjugation, radiochemistry and nanoscience. It meets an ever-increasing need for rapid reaction as it fulfills the criterion of an ideal synthesis: efficiency, versatility, selectivity and high yield with variety of starting materials. The present review summarizes all the aspects of 1, 3-dipolar cycloaddition reaction “click reaction” between azides and alkynes catalyzed by copper salts. The ease of purification of products and simplicity of this reaction has opened new pathways in generating vast arrays of compounds with biological potential. Many important reactions fit the concept of click chemistry than others such as cycloaddition of unsaturated species. The present review will outline the deeds of click reaction and its medicinal chemistry application in which click chemistry might be relevant in future.

  14. A multi-phase level set framework for source reconstruction in bioluminescence tomography

    International Nuclear Information System (INIS)

    We propose a novel multi-phase level set algorithm for solving the inverse problem of bioluminescence tomography. The distribution of unknown interior source is considered as piecewise constant and represented by using multiple level set functions. The localization of interior bioluminescence source is implemented by tracing the evolution of level set function. An alternate search scheme is incorporated to ensure the global optimal of reconstruction. Both numerical and physical experiments are performed to evaluate the developed level set reconstruction method. Reconstruction results show that the proposed method can stably resolve the interior source of bioluminescence tomography.

  15. Clicks versus Citations: Click Count as a Metric in High Energy Physics Publishing

    Energy Technology Data Exchange (ETDEWEB)

    Bitton, Ayelet; /UC, San Diego /SLAC

    2011-06-22

    High-energy physicists worldwide rely on online resources such as SPIRES and arXiv to perform gather research and share their own publications. SPIRES is a tool designed to search the literature within high-energy physics, while arXiv provides the actual full-text documents of this literature. In high-energy physics, papers are often ranked according to the number of citations they acquire - meaning the number of times a later paper references the original. This paper investigates the correlation between the number of times a paper is clicked in order to be downloaded and the number of citations it receives following the click. It explores how physicists truly read what they cite.

  16. Sources

    International Nuclear Information System (INIS)

    This paper discusses the sources of radiation in the narrow perspective of radioactivity and the even narrow perspective of those sources that concern environmental management and restoration activities at DOE facilities, as well as a few related sources. Sources of irritation, Sources of inflammatory jingoism, and Sources of information. First, the sources of irritation fall into three categories: No reliable scientific ombudsman to speak without bias and prejudice for the public good, Technical jargon with unclear definitions exists within the radioactive nomenclature, and Scientific community keeps a low-profile with regard to public information. The next area of personal concern are the sources of inflammation. This include such things as: Plutonium being described as the most dangerous substance known to man, The amount of plutonium required to make a bomb, Talk of transuranic waste containing plutonium and its health affects, TMI-2 and Chernobyl being described as Siamese twins, Inadequate information on low-level disposal sites and current regulatory requirements under 10 CFR 61, Enhanced engineered waste disposal not being presented to the public accurately. Numerous sources of disinformation regarding low level radiation high-level radiation, Elusive nature of the scientific community, The Federal and State Health Agencies resources to address comparative risk, and Regulatory agencies speaking out without the support of the scientific community

  17. People’s Ability to Detect Objects Using Click-Based Echolocation: A Direct Comparison between Mouth-Clicks and Clicks Made by a Loudspeaker

    Science.gov (United States)

    Thaler, Lore; Castillo-Serrano, Josefina

    2016-01-01

    Echolocation is the ability to use reflected sound to obtain information about the spatial environment. Echolocation is an active process that requires both the production of the emission as well as the sensory processing of the resultant sound. Appreciating the general usefulness of echo-acoustic cues for people, in particular those with vision impairments, various devices have been built that exploit the principle of echolocation to obtain and provide information about the environment. It is common to all these devices that they do not require the person to make a sound. Instead, the device produces the emission autonomously and feeds a resultant sound back to the user. Here we tested if echolocation performance in a simple object detection task was affected by the use of a head-mounted loudspeaker as compared to active clicking. We found that 27 sighted participants new to echolocation did generally better when they used a loudspeaker as compared to mouth-clicks, and that two blind participants with experience in echolocation did equally well with mouth clicks and the speaker. Importantly, performance of sighted participants’ was not statistically different from performance of blind experts when they used the speaker. Based on acoustic click data collected from a subset of our participants, those participants whose mouth clicks were more similar to the speaker clicks, and thus had higher peak frequencies and sound intensity, did better. We conclude that our results are encouraging for the consideration and development of assistive devices that exploit the principle of echolocation. PMID:27135407

  18. Performance Evaluation of Multicarrier SPWM Strategies for Three Phase Z - source Seven Level Diode Clamped Inverter

    OpenAIRE

    V.Arun#1 , B.Shanthi

    2013-01-01

    This paper presents multicarrier PWM strategies for three phase diode clamped seven level Z-source inverter. Multilevel inverters posses the advantage of reduced harmonics,high power capability and high voltage level. Impedance network in the diode clamped multilevel inverter circuit will perform boost operation. This paper focuses on multicarriersinusoidal pulse width modulation (MCSPWM) strategy for the three phase seven level Z-source diode clamped inverter. Performance parameters of three...

  19. Performance Evaluation of Three-Level Z-Source Inverters Under Semiconductor-Failure Conditions

    DEFF Research Database (Denmark)

    Gao, Feng; Loh, Poh Chiang; Blaabjerg, Frede;

    2009-01-01

    This paper evaluates and proposes various compensation methods for three-level Z-source inverters under semiconductor-failure conditions. Unlike the fault-tolerant techniques used in traditional three-level inverters, where either an extra phase-leg or collective switching states are used, the...... proposed methods for three-level Z-source inverters simply reconfigure their relevant gating signals so as to ride-through the failed semiconductor conditions smoothly without any significant decrease in their ac-output quality and amplitude. These features are partly attributed to the inherent boost...... characteristics of a Z-source inverter, in addition to its usual voltage-buck operation. By focusing on specific types of three-level Z-source inverters, it can also be shown that, for the dual Z-source inverters, a unique feature accompanying it is its extra ability to force common-mode voltage to zero even...

  20. High source levels and small active space of high pitched song in bowhead whales (Balaena mysticetus)

    DEFF Research Database (Denmark)

    Tervo, Outi Maria; Christoffersen, Mads F.; Simon, Malene;

    2012-01-01

    whales, estimate source levels and measure ambient noise. The song had a mean apparent source level of 185 ± 2 dB rms re 1µPa and a high mean centroid frequency of 444 ± 48 Hz. Using measured ambient noise levels in the area and Arctic sound spreading models, the estimated active space of these song...... attenuation. Here we evaluate the active space of high-pitched song notes of bowhead whales (Balaena mysticetus) in Western Greenland using measurements of song source levels and ambient noise. Four independent GPS-synchronized hydrophones were deployed through holes in the ice to localize vocalizing bowhead...... notes is between 40 and 130 km, an order of magnitude smaller than the estimated active space of low frequency blue and fin whale songs produced at similar source levels and for similar noise conditions. We propose that bowhead whales spatially compensate for their smaller communication range through...

  1. Lateralization of High-Frequency Clicks Based on Interaural Time: Additivity of Information across Frequency

    Science.gov (United States)

    Wenzel, Elizabeth Marie

    Lateralization performance based on interaural differences of time (IDTs) was measured for trains of Gaussian clicks which varied in spectral content. In the first experiment, thresholds ((DELTA)IDTs) were measured as a function of the number of clicks in the train (n = 1 to 32), the interclick interval (ICI = 2.5 or 5 ms), and the spectral content (1 vs. 2 or 4 carriers). Subjects' performance was compared to perfect statistical summation which predicts slopes of -.50 when log-(DELTA)IDT vs. long -n is plotted. The results showed that increasing the spectral content of the clicks decreased the intercepts of the log -log functions (decreased thresholds) while having little effect on their slopes. Shortening the ICIs caused the slopes of the functions to decrease in absolute value. To estimate the bandwidth of frequency-interaction in lateralization, d's were measured for clicks with constant IDTs (n = 1) with a fixed carrier (FF = 4000, 5200, 6000 or 7200 Hz), both alone and combined with a second click whose carrier (F) varied from 3500 to 8500 Hz. Performance in combined conditions was compared to independent summation of the information carried by the two frequency-bands. Performance improved as the separation between F and FF increased until the level predicted by independence was reached. The final experiment investigated the interaction of frequency content with IDT. d's were measured as a function of the IDT in clicks with carriers of 5200, 6000 or 7200 Hz, both alone and combined with a 4000-Hz click with a fixed IDT. Performance in combined conditions was again compared to independent additivity. The improvement with frequency was explained by an increase in the number of samples of the IDT reaching the binaural centers due to spread of excitation along the basilar membrane. Less than independent summation was explained by correlation between overlapping bands which reduced the amount of information exciting independent channels. The data also suggest that

  2. Background information on sources of low-level radionuclide emissions to air

    Energy Technology Data Exchange (ETDEWEB)

    Corbit, C.D.; Herrington, W.N.; Higby, D.P.; Stout, L.A.; Corley, J.P.

    1983-09-01

    This report provides a general description and reported emissions for eight low-level radioactive source categories, including facilties that are licensed by the Nuclear Regulatory Commission (NRC) and Agreement States, and non-Department of Energy (DOE) federal facilities. The eight categories of low-level radioactive source facilities covered by this report are: research and test reactors, accelerators, the radiopharmaceutical industry, source manufacturers, medical facilities, laboratories, naval shipyards, and low-level commercial waste disposal sites. Under each category five elements are addressed: a general description, a facility and process description, the emission control systems, a site description, and the radionuclides released to air (from routine operations).

  3. Control and design of full-bridge three-level converter for renewable energy sources

    DEFF Research Database (Denmark)

    Yao, Zhilei; Xu, Jing; Guerrero, Josep M.

    2015-01-01

    Output voltage of renewable energy sources, such as fuel cell and PV cell, is often low and varies widely with load and environmental conditions. Therefore, the high step-up DC-DC converter is needed between renewable energy sources and the grid-connected inverter. However, voltage stress of...... rectifier diodes is high and filter is large in traditional voltage-source converters in a wide input-voltage range. In order to solve the aforementioned problems, a full-bridge (FB) three-level (TL) converter is proposed. It can operate at both two-level and three-level modes, so it is suitable for wide...

  4. Background information on sources of low-level radionuclide emissions to air

    International Nuclear Information System (INIS)

    This report provides a general description and reported emissions for eight low-level radioactive source categories, including facilties that are licensed by the Nuclear Regulatory Commission (NRC) and Agreement States, and non-Department of Energy (DOE) federal facilities. The eight categories of low-level radioactive source facilities covered by this report are: research and test reactors, accelerators, the radiopharmaceutical industry, source manufacturers, medical facilities, laboratories, naval shipyards, and low-level commercial waste disposal sites. Under each category five elements are addressed: a general description, a facility and process description, the emission control systems, a site description, and the radionuclides released to air (from routine operations)

  5. OneClick: A Program for Designing Focused Mutagenesis Experiments

    Directory of Open Access Journals (Sweden)

    Mark Warburton

    2015-07-01

    Full Text Available OneClick is a user-friendly web-based program, developed specifically for quick-and-easy design of focused mutagenesis experiments (e.g., site-directed mutagenesis and saturation mutagenesis. Written in Perl and developed into a web application using CGI programming, OneClick offers a step-by-step experimental design, from mutagenic primer design to analysis of a mutant library. Upon input of a DNA sequence encoding the protein of interest, OneClick designs the mutagenic primers according to user input, e.g., amino acid position to mutate, type of amino acid substitutions (e.g., substitution to a group of amino acids with similar chemical property and type of mutagenic primers. OneClick has incorporated an extensive range of commercially available plasmids and DNA polymerases suitable for focused mutagenesis. Therefore, OneClick also provides information on PCR mixture preparation, thermal cycling condition, expected size of PCR product and agar plate to use during bacterial transformation. Importantly, OneClick also carries out a statistical analysis of the resultant mutant library, information of which is important for selection/screening. OneClick is a unique and invaluable tool in the field of protein engineering, allowing for systematic construction of a mutant library or a protein variant and simplifying molecular biology work. The program will be constantly updated to reflect the rapid development in the fields of molecular biology and protein engineering.

  6. Formation of click-wrap and browse-wrap contracts

    OpenAIRE

    Kamantauskas, Povilas

    2014-01-01

    In a time of rapid development of technologies, new forms of contracting online emerge. Two of these are analyzed in this thesis: click-wrap agreements (where an offer is accepted by way of clicking on an icon “I agree”) and browse-wrap agreements (where the offeree supposedly accepts the offer by browsing on a website, while the terms to the contract are accessible through an inconspicuous hyperlink). Click-wrap agreements are formed, they are accepted in a manner recognized as binding an...

  7. Design and comparison of three-level three-phase T-source inverters

    DEFF Research Database (Denmark)

    Shults, T.; Husev, Oleksandr; Blaabjerg, Frede

    2015-01-01

    This paper presents guidelines for component design of recently proposed topologies of the three-level three-phase T-source inverters. Two different topologies are considered: T-source inverters with discontinuous input current and T-source inverters with continuous input current. Steady state...... analysis and estimation of components size for both schemes are described and compared. Simulation results have confirmed most of theoretical predictions....

  8. Sources of innovation, their combinations and strengths – benefits at the NPD project level

    DEFF Research Database (Denmark)

    Tranekjer, Tina Lundø; Søndergaard, Helle Alsted

    2013-01-01

    External sourcing is increasingly seen as important for obtaining new and valuable knowledge and resources for new product development. However, when it comes to the specifics of choosing between sources and types of relationships, little is known on the NPD project level. This paper strengthens ...

  9. Sulphur uptake and utilization by safflower as affected by sources and levels of application

    International Nuclear Information System (INIS)

    Pot culture experiment was carried out with a coarse loamy Ustocrept soil, to study the effect of sulphur sources and levels on dry matter yield, total sulphur uptake at different stages of growth, per cent Sdff and per cent utilization of applied sulphur at maturity in safflower crop. Sulphur was applied from four different sources viz. magnesium sulphate, ammonium sulphate, ferrous sulphate and gypsum each at five levels viz. 0, 9, 18, 27 and 36 μg-1 soil. (author)

  10. Levels and source apportionment of children's lead exposure: could urinary lead be used to identify the levels and sources of children's lead pollution?

    Science.gov (United States)

    Cao, Suzhen; Duan, Xiaoli; Zhao, Xiuge; Wang, Beibei; Ma, Jin; Fan, Delong; Sun, Chengye; He, Bin; Wei, Fusheng; Jiang, Guibin

    2015-04-01

    As a highly toxic heavy metal, the pollution and exposure risks of lead are of widespread concern for human health. However, the collection of blood samples for use as an indicator of lead pollution is not always feasible in most cohort or longitudinal studies, especially those involving children health. To evaluate the potential use of urinary lead as an indicator of exposure levels and source apportionment, accompanying with environmental media samples, lead concentrations and isotopic measurements (expressed as (207)Pb/(206)Pb, (208)Pb/(206)Pb and (204)Pb/(206)Pb) were investigated and compared between blood and urine from children living in the vicinities of a typical coking plant and lead-acid battery factory. The results showed urinary lead might not be a preferable proxy for estimating blood lead levels. Fortunately, urinary lead isotopic measurements could be used as an alternative for identifying the sources of children's lead exposure, which coincided well with the blood lead isotope ratio analysis. PMID:25617855

  11. Potential Application of Pheromones in Monitoring, Mating Disruption, and Control of Click Beetles (Coleoptera: Elateridae)

    OpenAIRE

    Gadi V.P. Reddy; Tangtrakulwanich, Khanobporn

    2014-01-01

    Wireworms, the larvae stage of click beetles (family, Elateridae), are serious soil dwelling pests of small grain, corn, sugar beet, and potato crops globally. Since the 1950s, conventional insecticides such as lindane provided effective and inexpensive protection from wireworms, and little integrated pest management research (IPM) was conducted. The removal of these products from the agricultural market, particularly Lindane, has resulted in increasing levels of wireworm damage to small grai...

  12. Click Chemistry in Peptide-Based Drug Design

    Directory of Open Access Journals (Sweden)

    Irwin Chaiken

    2013-08-01

    Full Text Available Click chemistry is an efficient and chemoselective synthetic method for coupling molecular fragments under mild reaction conditions. Since the advent in 2001 of methods to improve stereochemical conservation, the click chemistry approach has been broadly used to construct diverse chemotypes in both chemical and biological fields. In this review, we discuss the application of click chemistry in peptide-based drug design. We highlight how triazoles formed by click reactions have been used for mimicking peptide and disulfide bonds, building secondary structural components of peptides, linking functional groups together, and bioconjugation. The progress made in this field opens the way for synthetic approaches to convert peptides with promising functional leads into structure-minimized and more stable forms.

  13. Applications of Azide-Based Bioorthogonal Click Chemistry in Glycobiology

    Directory of Open Access Journals (Sweden)

    Xiu Zhang

    2013-06-01

    Full Text Available Click chemistry is a powerful chemical reaction with excellent bioorthogonality features: biocompatible, rapid and highly specific in biological environments. For glycobiology, bioorthogonal click chemistry has created a new method for glycan non-invasive imaging in living systems, selective metabolic engineering, and offered an elite chemical handle for biological manipulation and glycomics studies. Especially the [3 + 2] dipolar cycloadditions of azides with strained alkynes and the Staudinger ligation of azides and triarylphosphines have been widely used among the extant click reactions. This review focuses on the azide-based bioorthogonal click chemistry, describing the characteristics and development of these reactions, introducing some recent applications in glycobiology research, especially in glycan metabolic engineering, including glycan non-invasive imaging, glycomics studies and viral surface manipulation for drug discovery as well as other applications like activity-based protein profiling and carbohydrate microarrays.

  14. Seven deadly clicks essential lessons for online safety and success

    CERN Document Server

    Strupeck, Margo

    2013-01-01

    Pulling examples from high-profile pop culture cases, Seven Deadly Clicks explains the very real dangers behind common online activities, and offers advice on how to not only stay safe, but also thrive.

  15. Click Chemistry-Mediated Nanosensors for Biochemical Assays

    Science.gov (United States)

    Chen, Yiping; Xianyu, Yunlei; Wu, Jing; Yin, Binfeng; Jiang, Xingyu

    2016-01-01

    Click chemistry combined with functional nanoparticles have drawn increasing attention in biochemical assays because they are promising in developing biosensors with effective signal transformation/amplification and straightforward signal readout for clinical diagnostic assays. In this review, we focus on the latest advances of biochemical assays based on Cu (I)-catalyzed 1, 3-dipolar cycloaddition of azides and alkynes (CuAAC)-mediated nanosensors, as well as the functionalization of nanoprobes based on click chemistry. Nanoprobes including gold nanoparticles, quantum dots, magnetic nanoparticles and carbon nanomaterials are covered. We discuss the advantages of click chemistry-mediated nanosensors for biochemical assays, and give perspectives on the development of click chemistry-mediated approaches for clinical diagnosis and other biomedical applications. PMID:27217831

  16. Recent Advances in Click Chemistry Applied to Dendrimer Synthesis

    Directory of Open Access Journals (Sweden)

    Mathieu Arseneault

    2015-05-01

    Full Text Available Dendrimers are monodisperse polymers grown in a fractal manner from a central point. They are poised to become the cornerstone of nanoscale devices in several fields, ranging from biomedicine to light-harvesting. Technical difficulties in obtaining these molecules has slowed their transfer from academia to industry. In 2001, the arrival of the “click chemistry” concept gave the field a major boost. The flagship reaction, a modified Hüisgen cycloaddition, allowed researchers greater freedom in designing and building dendrimers. In the last five years, advances in click chemistry saw a wider use of other click reactions and a notable increase in the complexity of the reported structures. This review covers key developments in the click chemistry field applied to dendrimer synthesis from 2010 to 2015. Even though this is an expert review, basic notions and references have been included to help newcomers to the field.

  17. Design and synthesis of multivalent neoglycoconjugates by click conjugations

    Directory of Open Access Journals (Sweden)

    Feiqing Ding

    2014-06-01

    Full Text Available A highly stereoselective BF3∙OEt2-promoted tandem hydroamination/glycosylation on glycal scaffolds has been developed to form propargyl 3-tosylamino-2,3-dideoxysugars in a one-pot manner. Subsequent construction of multivalent 3-tosylamino-2,3-dideoxyneoglycoconjugates with potential biochemical applications was presented herein involving click conjugations as the key reaction step. The copper-catalyzed regioselective click reaction was tremendously accelerated with assistance of microwave irradiation.

  18. Social Clicks: What and Who Gets Read on Twitter?

    OpenAIRE

    Gabielkov, Maksym; Ramachandran, Arthi; Chaintreau, Augustin; Legout, Arnaud

    2016-01-01

    Online news domains increasingly rely on social media to drive traffic to their websites. Yet we know surprisingly little about how a social media conversation mentioning an online article actually generates clicks. Sharing behaviors, in contrast, have been fully or partially available and scrutinized over the years. While this has led to multiple assumptions on the diffusion of information, each assumption was designed or validated while ignoring actual clicks. We present a large scale, unbi...

  19. Performance Evaluation of Three-Level Z-Source Inverters Under Semiconductor Failure Conditions

    DEFF Research Database (Denmark)

    Gao, Feng; Loh, P.C.; Vilathgamuwa, D.M.; Blaabjerg, Frede

    This paper proposes various compensation methods for three-level Z-source inverters under semiconductor failure conditions. Unlike the traditional fault tolerant techniques in three-level inverter by using either an additional phase-leg or collective switching states, the proposed methods simply ...

  20. Nonecholocating fruit bats produce biosonar clicks with their wings.

    Science.gov (United States)

    Boonman, Arjan; Bumrungsri, Sara; Yovel, Yossi

    2014-12-15

    Because evolution mostly acts over millions of years, the intermediate steps leading to a functional sensory system remain enigmatic. Accordingly, there is an ongoing debate regarding the evolution of bat echolocation. In search of the origin of bat echolocation, we studied how Old World fruit bats, which have always been classified as nonecholocating, orient in complete darkness. We found that two of these nonecholocating species used click-like sounds to detect and discriminate objects in complete darkness. However, we discovered that this click-based echo sensing is rudimentary and does not allow these bats to estimate distance accurately as all other echolocating bats can. Moreover, unlike all other echolocating bats, which generate pulses using the larynx or the tongue, these bats generated clicks with their wings. We provide evidence suggesting that all Old World fruit bats can click with their wings. Although this click-based echo sensing used by Old World fruit bats may not represent the ancestral form of current (laryngeal) bat echolocation, we argue that clicking fruit bats could be considered behavioral fossils, opening a window to study the evolution of echolocation. PMID:25484290

  1. Implementation of E.U. Water Framework Directive: source assessment of metallic substances at catchment levels.

    Science.gov (United States)

    Chon, Ho-Sik; Ohandja, Dieudonne-Guy; Voulvoulis, Nikolaos

    2010-01-01

    The E.U. Water Framework Directive (WFD) aims to prevent deterioration of water quality and to phase out or reduce the concentrations of priority substances at catchment levels. It requires changes in water management from a local scale to a river basin scale, and establishes Environmental Quality Standards (EQS) as a guideline for the chemical status of receiving waters. According to the Directive, the standard and the scope of the investigation for water management are more stringent and expanded than in the past, and this change also needs to be applied to restoring the level of metals in water bodies. The aim of this study was to identify anthropogenic emission sources of metallic substances at catchment levels. Potential sources providing substantial amounts of such substances in receiving waters included stormwater, industrial effluents, treated effluents, agricultural drainage, sediments, mining drainage and landfill leachates. Metallic substances have more emission sources than other dangerous substances at catchment levels. Therefore, source assessment for these substances is required to be considered more significantly to restore their chemical status in the context of the WFD. To improve source assessment quality, research on the role of societal and environmental parameters and contribution of each source to the chemical distribution in receiving waters need to be carried out. PMID:20081997

  2. Determination of Noise Level and Its Sources in the Neonatal Intensive Care Unit and Neonatal Ward

    Directory of Open Access Journals (Sweden)

    Mahdi Jahangir Blourchian

    2015-12-01

    Full Text Available Background: In Neonatal intensive care units (NICU different sound intensities and frequencies are produced from different sources, which may exert undesirable physiological effects on the infants. The aim of this study was to determine the noise level and its sources in the NICU and neonatal ward of Al-Zahra Hospital of Rasht, Iran. Methods: In this descriptive cross-sectional study, the intensity of the sounds generated by the internal and external sources in the NICU and neonatal ward was measured using a sound level meter device. The sound produced by each of the sources was individually calculated. Data were analyzed performing descriptive and analytical statistics, using SPSS version 19. Results: The mean noise levels in six rooms and a hallway during morning, afternoon and night shifts with the electromechanical devices turned on were 61.67±4.5, 61.32±4.32 and 60.71±4.56 dB, respectively. Moreover, with the devices tuned off the mean noise levels during morning, afternoon and evening shifts were 64.97±2.6, 60.6±1.29 and 57.91±4.73 dB, respectively. The differences between the mean noise levels in the neonatal wards (standard noise level=45 dB during each shift with the electromechanical devices turned on and off were statistically significant (P=0.002 and P

  3. Low-level waste disposal performance assessments - Total source-term analysis

    Energy Technology Data Exchange (ETDEWEB)

    Wilhite, E.L.

    1995-12-31

    Disposal of low-level radioactive waste at Department of Energy (DOE) facilities is regulated by DOE. DOE Order 5820.2A establishes policies, guidelines, and minimum requirements for managing radioactive waste. Requirements for disposal of low-level waste emplaced after September 1988 include providing reasonable assurance of meeting stated performance objectives by completing a radiological performance assessment. Recently, the Defense Nuclear Facilities Safety Board issued Recommendation 94-2, {open_quotes}Conformance with Safety Standards at Department of Energy Low-Level Nuclear Waste and Disposal Sites.{close_quotes} One of the elements of the recommendation is that low-level waste performance assessments do not include the entire source term because low-level waste emplaced prior to September 1988, as well as other DOE sources of radioactivity in the ground, are excluded. DOE has developed and issued guidance for preliminary assessments of the impact of including the total source term in performance assessments. This paper will present issues resulting from the inclusion of all DOE sources of radioactivity in performance assessments of low-level waste disposal facilities.

  4. Levels and Sources of Language Anxiety and Fear of Negative Evaluation among Iranian EFL Learners

    OpenAIRE

    Mohammad Bagher Shabani

    2012-01-01

    Anxiety, as an important affective variable, has been found to be a significant factor adversely affecting language learning (Aydin 2008).  Many studies have explored sources and causes of anxiety among learners (Young, 1991; Tanveer, 2007; Aydin 2008; Williams& Andrade, 2008). However, to date little, if any, studies have examined levels and sources of anxiety and its relationship with fear of negative evaluation. To this end, the present study has been conducted in Iranian context....

  5. Dual Z-Source Inverter With Three-Level Reduced Common-Mode Switching

    DEFF Research Database (Denmark)

    Gao, Feng; Loh, Poh Chiang; Blaabjerg, Frede;

    2007-01-01

    This paper presents the design of a dual Z-source inverter that can be used with either a single dc source or two isolated dc sources. Unlike traditional inverters, the integration of a properly designed Z-source network and semiconductor switches to the proposed dual inverter allows buck......-boost power conversion to be performed over a wide modulation range, with three-level output waveforms generated. The connection of an additional transformer to the inverter ac output also allows all generic wye-or delta-connected loads with three-wire or four-wire configuration to be supplied by the inverter....... Modulationwise, the dual inverter can be controlled using a carefully designed carrier-based pulsewidth-modulation (PWM) scheme that will always ensure balanced voltage boosting of the Z-source network while simultaneously achieving reduced common-mode switching. Because of the omission of dead-time delays in...

  6. Analysis of Current Source PWM Inverter for Different Levels with No-Insulating Switching Device

    Directory of Open Access Journals (Sweden)

    Kumar Abhishek

    2013-04-01

    Full Text Available This paper gives the new set-up of inverter having DC current source (CSI having no insulated switching device. In the proposed new CSI topology every switching device are connected across a common-source level, thus a single power supply gate drive circuit is required and no insulated power supply and the customary bootstrap circuit is applied. This CSI topology is even legitimate for utmost level of current waveform output, where the power switches number increases. As a turn up, gate drive complexity is reduced, and it also eliminates the cost of capacitors and transformers in switching devices, driver circuits. In addition, this new topology of current-source PWM inverter (CSI can operate even at utmost switching frequency, as every switches will be connected across a common source level. In this paper the different level of proposed CSI operation principle, its design using computer simulation (MATLAB with its total harmonic distortion (THD is analyzed. The computer simulation using MATLAB determines the feasibility of this topology with the analysis of different level which results in reduction of its complexity and the physical size.

  7. Source-term development for commercial low-level radioactive waste

    International Nuclear Information System (INIS)

    Generic source terms base don historical data have been developed for commerical low-level radioactive waste (LLRW) from fuel-cycle and non-fuel-cycle facilities. These source terms are used in DOE's Integrated Data Base (IDB) Program to estimate historical and projected volumes, radioactivity, and thermal power (from radioactive decay) of LLRW to the year 2020. Periodically, the source terms are updated as new waste is generated and as information on older waste is reviewed, redefined, and upgraded by the generator. Other segments of the nuclear industry also use source terms in planning for waste treatment, transportation, and storage systems. Several uses of source terms are illustrated. For example, the reported volume and radioactivity of LLRW added annually to commerical burial sites are compared with the calculated annual values obtained by summing contributions based on source terms for each generator. Likewise, accumulative radioactivity and thermal power of buried LLRW obtained by using an average source term and a synthesis of individual source terms are compared. 6 refs., 8 figs, 5 tabs

  8. Clicking caterpillars: acoustic aposematism in Antheraea polyphemus and other Bombycoidea.

    Science.gov (United States)

    Brown, Sarah G; Boettner, George H; Yack, Jayne E

    2007-03-01

    Acoustic signals produced by caterpillars have been documented for over 100 years, but in the majority of cases their significance is unknown. This study is the first to experimentally examine the phenomenon of audible sound production in larval Lepidoptera, focusing on a common silkmoth caterpillar, Antheraea polyphemus (Saturniidae). Larvae produce airborne sounds, resembling ;clicks', with their mandibles. Larvae typically signal multiple times in quick succession, producing trains that last over 1 min and include 50-55 clicks. Individual clicks within a train are on average 24.7 ms in duration, often consisting of multiple components. Clicks are audible in a quiet room, measuring 58.1-78.8 dB peSPL at 10 cm. They exhibit a broadband frequency that extends into the ultrasound spectrum, with most energy between 8 and 18 kHz. Our hypothesis that clicks function as acoustic aposematic signals, was supported by several lines of evidence. Experiments with forceps and domestic chicks correlated sound production with attack, and an increase in attack rate was positively correlated with the number of signals produced. In addition, sound production typically preceded or accompanied defensive regurgitation. Bioassays with invertebrates (ants) and vertebrates (mice) revealed that the regurgitant is deterrent to would-be predators. Comparative evidence revealed that other Bombycoidea species, including Actias luna (Saturniidae) and Manduca sexta (Sphingidae), also produce airborne sounds upon attack, and that these sounds precede regurgitation. The prevalence and adaptive significance of warning sounds in caterpillars is discussed. PMID:17337712

  9. In-source resonance ionization spectroscopy of high lying energy levels in atomic uranium

    International Nuclear Information System (INIS)

    In-source resonance ionization spectroscopy of uranium has been carried out as preparation for the analysis of low contaminations of nuclear material in environmental samples via laser mass spectrometry. Using three-step resonance ionization spectroscopy, 86 levels of odd parity in the energy range from 37,200-38,650 cm-1 were studied, 51 of these levels were previously unknown. Suitable excitation schemes for analytic applications are discussed.

  10. In-source resonance ionization spectroscopy of high lying energy levels in atomic uranium

    Science.gov (United States)

    Raeder, Sebastian; Fies, Silke; Gottwald, Tina; Mattolat, Christoph; Rothe, Sebastian; Wendt, Klaus

    2010-02-01

    In-source resonance ionization spectroscopy of uranium has been carried out as preparation for the analysis of low contaminations of nuclear material in environmental samples via laser mass spectrometry. Using three-step resonance ionization spectroscopy, 86 levels of odd parity in the energy range from 37,200-38,650 cm - 1 were studied, 51 of these levels were previously unknown. Suitable excitation schemes for analytic applications are discussed.

  11. In-source resonance ionization spectroscopy of high lying energy levels in atomic uranium

    Energy Technology Data Exchange (ETDEWEB)

    Raeder, Sebastian, E-mail: raeder@uni-mainz.de; Fies, Silke; Gottwald, Tina; Mattolat, Christoph [Johannes Gutenberg-Universitaet Mainz, Institut fuer Physik (Germany); Rothe, Sebastian [CERN, Engineering Department (Switzerland); Wendt, Klaus [Johannes Gutenberg-Universitaet Mainz, Institut fuer Physik (Germany)

    2010-02-15

    In-source resonance ionization spectroscopy of uranium has been carried out as preparation for the analysis of low contaminations of nuclear material in environmental samples via laser mass spectrometry. Using three-step resonance ionization spectroscopy, 86 levels of odd parity in the energy range from 37,200-38,650 cm{sup -1} were studied, 51 of these levels were previously unknown. Suitable excitation schemes for analytic applications are discussed.

  12. A review of studies on low-level vibrations as a source of electric power generation

    OpenAIRE

    RAHMATİAN, Mohammad Ali; RAHMATİAN, Mohammad Rasoul; RAHİMZADEH, Hamed

    2015-01-01

    Abstract. Recent advances in low power VLSI design, with a low duty cycle has been able to resolve wireless sensor problems. In addition, researchers are looking to generate electrical energy from vibrations. The present paper discusses the low level vibration sources and their use in piezoelectric circuit for the production of electrical energy. The simulation results show that this scheme can convert low-level vibrations in nature, home environment, workplace, etc. into electrical energy.

  13. DEVELOPMENT OF AUDIT DEVICES AND MATERIALS FOR SOURCE LEVEL AIR POLLUTION MEASUREMENT METHODS

    Science.gov (United States)

    The paper describes the procedures followed by the U.S. Environmental Protection Agency (EPA), Quality Assurance Division, when developing a source level audit device or material (d/m). The audit d/m's are used to quantitatively determine that an EPA reference method is being pro...

  14. Blue and fin whale call source levels and propagation range in the Southern Ocean.

    Science.gov (United States)

    Sirović, Ana; Hildebrand, John A; Wiggins, Sean M

    2007-08-01

    Blue (Balaenoptera musculus) and fin whales (B. physalus) produce high-intensity, low-frequency calls, which probably function for communication during mating and feeding. The source levels of blue and fin whale calls off the Western Antarctic Peninsula were calculated using recordings made with calibrated, bottom-moored hydrophones. Blue whales were located up to a range of 200 km using hyperbolic localization and time difference of arrival. The distance to fin whales, estimated using multipath arrivals of their calls, was up to 56 km. The error in range measurements was 3.8 km using hyperbolic localization, and 3.4 km using multipath arrivals. Both species produced high-intensity calls; the average blue whale call source level was 189+/-3 dB re:1 microPa-1 m over 25-29 Hz, and the average fin whale call source level was 189+/-4 dB re:1 microPa-1 m over 15-28 Hz. Blue and fin whale populations in the Southern Ocean have remained at low numbers for decades since they became protected; using source level and detection range from passive acoustic recordings can help in calculating the relative density of calling whales. PMID:17672667

  15. Pulse width modulated buck-boost five-level current source inverters

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Gao, F.; Loh, P.C.;

    2008-01-01

    This paper presents new five-level current source inverters (CSIs) with voltage/current buck-boost capability. Being different from the existing multilevel CSI, the proposed CSIs were first designed to regulate the flowing path of dc input current by controlling two additional active switches, re...

  16. Design and development of source holder of collimator assembly for low level radiological testing and calibration

    International Nuclear Information System (INIS)

    The low level radiological test and calibration facility under ISO: 17025; NABL accreditation has been recently upgraded in terms of radiation source strength and radiation collimation geometry. The decayed cobalt-60 radiation source (2.3 mCi) has been replenished with new radioactive source of activity 10 mCi. The source was procured from BRIT Mumbai with physical dimension 15 mm (L) x 10 mm (f), however, the active geometry of the source was not known. An autoradiography concept was applied to know the exact geometry of active dimension of the source with respect to its physical dimension. The source was immobilized on the industrial radiography film and exposed with X-rays (KV: 100, mA: 1, t: 0.5 s) at 100 cm from focal point of X-ray tube. The film was developed under standard laboratory condition in the dark room. The radioactive pellet has been found well delineated with respect to the physical dimension of the source inside the capsule. The exact physical dimension of the source and active dimension have been found as 9 mm (L) x 8 mm (f) and 3 mm (L) x 2 mm (f) respectively. A source holder of perspex material was designed and fabricated as per collimator geometry, ease of fitment and divergence profile of radiation beam. The autoradiography procedure (KV: 70, mA: 1, t: 0.7 s) was repeated after fixing the source in fabricated perpex holder for checking the quality of the immobilization of source in the holder. An improvement in positioning error (±5 mm) while testing and calibrating the radiological instruments, has been observed with the help of autoradiograph. The alignment of the source was checked and verified with laser alignment system. The designed collimator is made of tissue equivalent material and hence will have less radiation scattering. The radiological calibration facility is now more efficient in terms of systematic measurement uncertainty. This has improved the quality standard of the radiological test and calibration. The various aspects

  17. Temporal suppression and augmentation of click-evoked otoacoustic emissions

    DEFF Research Database (Denmark)

    Verhulst, Sarah; Harte, James; Dau, Torsten

    2008-01-01

    This study investigates and models temporal suppression of click-evoked otoacoustic emissions (CEOAEs). This suppression-effect is created when a suppressor-click is presented close in time to a test-click. The analysis was carried out for short time-frames of short- and long-latency CEOAEs. The...... latter is defined as a CEOAE with duration greater than 20 ms, typically observed for test subjects with spontaneous otoacoustic emissions (SOAEs). Previous studies have tended to exclude these test subjects but they are incorporated here. The results from six exemplary subjects demonstrate that temporal...... temporal suppression and augmentation of CEOAEs. Recently, a feedback automatic gain control (AGC) system has been used to model CEOAE suppression. However, this system cannot account for augmentation and therefore another, dynamic nonlinear model was developed. Suppression and augmentation were modeled...

  18. Uncovering Quantum Correlations with Time-Multiplexed Click Detection

    Science.gov (United States)

    Sperling, J.; Bohmann, M.; Vogel, W.; Harder, G.; Brecht, B.; Ansari, V.; Silberhorn, C.

    2015-07-01

    We report on the implementation of a time-multiplexed click detection scheme to probe quantum correlations between different spatial optical modes. We demonstrate that such measurement setups can uncover nonclassical correlations in multimode light fields even if the single mode reductions are purely classical. The nonclassical character of correlated photon pairs, generated by a parametric down-conversion, is immediately measurable employing the theory of click counting instead of low-intensity approximations with photoelectric detection models. The analysis is based on second- and higher-order moments, which are directly retrieved from the measured click statistics, for relatively high mean photon numbers. No data postprocessing is required to demonstrate the effects of interest with high significance, despite low efficiencies and experimental imperfections. Our approach shows that such novel detection schemes are a reliable and robust way to characterize quantum-correlated light fields for practical applications in quantum communications.

  19. System Integration of High Level Applications during the Commissioning of the Swiss Light Source

    OpenAIRE

    Luedeke, A.

    2001-01-01

    The commissioning of the Swiss Light Source (SLS) started in Feb. 2000 with the Linac, continued in May 2000 with the booster synchrotron and by Dec. 2000 first light in the storage ring were produced. The first four beam lines had to be operational by August 2001. The thorough integration of all subsystems to the control system and a high level of automation was prerequisite to meet the tight time schedule. A careful balanced distribution of functionality into high level and low level applic...

  20. Low levels of persistent organic pollutants (POPs) in New Zealand eels reflect isolation from atmospheric sources

    International Nuclear Information System (INIS)

    Polychlorinated biphenyls (PCBs) and organic pesticides (i.e., DDTs) were measured in long finned eels (Anguilla dieffenbachii) in 17 streams on the west coast of South Island, New Zealand. Very low levels of PCBs and low levels of ppDDE were found. The concentrations of PCBs and ppDDE were not correlated within sites indicating that different processes determined the levels of the two pollutants in New Zealand eels. The PCBs probably originate from atmospheric transport, ppDDE levels are determined by land use and are higher in agriculture areas. The low contamination level of these aquatic systems seems to be a function of a low input from both long and short-range transport as well as few local point sources. No correlation could be found between lipid content and persistent organic pollutants (POPs) concentration (as shown in previous studies) in the eels which could be explained by low and irregular intake of the pollutants. - Low levels of PCBs found in New Zealand eels reflect isolation from atmospheric sources while DDTs levels are determined by land use

  1. Effect of lipid sources and inclusion levels in diets for broiler chickens

    Directory of Open Access Journals (Sweden)

    G.V. Polycarpo

    2014-04-01

    Full Text Available This research aimed to evaluate the interactions and effects of 2 and 4% addition levels of poultry slaughterhouse fat (chicken tallow and soybean oil in diets for broiler chickens. Two experiments were carried out using one-day-old male Cobb chicks in an entirely random design with a 2x2 factorial scheme. In the first experiment, 560 chicks were used to evaluate performance and carcass characteristics. In the second experiment, 100 chicks were used to determine the nutrient digestibility, dietary energy utilization and the lipase and amylase pancreatic activity. There was no interaction between the fat sources and the addition levels for any of the analyzed variables, except for the digestibility coefficient of dry matter (DCDM, which was higher in diets added with 2% soybean oil when compared to chicken tallow. The addition of 4% fat in the diet, regardless of fat source, improved the digestibility coefficient of ethereal extract (DCEE and increased weight gain and feed intake. Moreover, in the initial phase, the addition of 4% fat to the diet increased lipase activity when compared to diets with 2% addition, and a positive correlation between DCEE and pancreatic lipase activity was observed. In conclusion, there is no interaction between fat sources and addition levels, except for DCDM. Carcass characteristics are not influenced by any of the studied factors. The addition of 4% fat increases pancreatic lipase activity and improves DCEE, resulting in greater weight gain, regardless of the tested fat source, making chicken tallow a great alternative to soybean oil.

  2. Mapping Air Pollution Concentrations and Sources in China from Ground-Level Observations

    Science.gov (United States)

    Rohde, R. A.; Muller, R. A.

    2014-12-01

    China has recently established an extensive air quality monitoring system with over 1500 sites providing hourly data on airborne particulate matter (PM2.5 / PM10), sulfur dioxide (SO2), nitrogen dioxide (NO2), ozone (O3), and carbon monoxide (CO). Based on Kriging interpolation of these surface data, we derive a detailed map of air pollution across the eastern half of China. In northern and central China, the pollution is widespread; contrary to popular belief, pollution is not simply localized to major cities such as Beijing, Shanghai, or Chongqing, or in geologic basins. Pollution levels are lower in southern China, in part due to frequent rains. By incorporating wind measurements and estimating pollution transport, we also infer source distributions for key pollutants. Sources are widespread, but many of the largest sources are often situated in or near major population centers. A northeast corridor extending from near Shanghai to north of Beijing includes many of the most significant pollution sources in China. Roughly 5% of the study region accounts for 25% of observed particulate matter emissions. During the analysis period, roughly half of the population of China was subjected to a long-term average pollution level in the unhealthy range, according to standards used by the US Environmental Protection Agency. In addition, nearly all of China's population (>90%) was exposed to unhealthy levels of air pollution at least some of the time. Based on health impact estimates from the Huai River Study, we estimate that the observed levels of particulate matter pollution contribute to about 1.4 million deaths every year in China, about 3500 per day, in agreement with prior estimates. Identification of sources from pollution data was facilitated by the reporting of hourly measurements, and we encourage other nations around the world to follow China's example and provide such time-resolved data.

  3. Cooperative capture synthesis: yet another playground for copper-free click chemistry.

    Science.gov (United States)

    Hou, Xisen; Ke, Chenfeng; Fraser Stoddart, J

    2016-07-21

    Click chemistry describes a family of modular, efficient, versatile and reliable reactions which have acquired a pivotal role as one of the most useful synthetic tools with a potentially broad range of applications. While copper(i)-catalysed alkyne-azide cycloaddition is the most widely adopted click reaction in the family, the fact that it is cytotoxic restricts its practice in certain situations, e.g., bioconjugation. Consequently, researchers have been exploring the development of copper-free click reactions, the most popular example so far being strain-promoted alkyne-azide cycloadditions. An early example of copper-free click reactions that is rarely mentioned in the literature is the cucurbit[6]uril (CB6) catalysed alkyne-azide cycloaddition (CB-AAC). Despite the unique ability of CB-AAC to generate mechanically interlocked molecules (MIMs) - in particular, rotaxanes - its slow reaction rate and narrow substrate acceptance limit its scope. In this Tutorial Review, we describe our efforts of late in developing the fundamental principles and practical applications of a new copper-free click reaction - namely, cooperative capture synthesis, whereby introducing a cyclodextrin (CD) as an accelerator in CB-AAC, hydrogen bonding networks are formed between the rims of CD and CB6 in a manner that is positively cooperative, giving rise to a high level of pre-organisation during efficient and quick rotaxane formation. For example, [4]rotaxanes can be prepared nearly quantitatively within a minute in water. Furthermore, we have demonstrated that CB-AAC can accommodate a wider substrate tolerance by introducing pillararenes as promoters. To date, we have put cooperative capture synthesis into practice by (i) preparing polyrotaxanes containing up to 200 rings in nearly quantitative yields, (ii) trapping conformational isomers of polymacrocycles as rings in rotaxanes, (iii) demonstrating solid-state fluorescence and Förster resonance energy transfer (FRET) processes by

  4. Three-Level Z-Source Inverters Using a Single LC Impedance Network

    DEFF Research Database (Denmark)

    Loh, Poh Chiang; Lim, Sok Wei; Gao, Feng;

    2007-01-01

    two LC impedance networks and two isolated dc sources, which can significantly increase the overall system cost and require a more complex modulator for balancing the network inductive voltage boosting. Offering a number of less costly alternatives, this letter presents the design and control of two...... three-level Z-source inverters, whose output voltage can be stepped down or up using only a single LC impedance network connected between the dc input source and either a neutral-point-clamped (NPC) or dc-link cascaded inverter circuitry. Through careful design of their modulation scheme, both inverters...... can conveniently be implemented using a generic "alternative phase opposition disposition" carrier-based modulator with the appropriate triplen offset and time advance/delay added. The designed inverters, having a reduced passive component count, are lastly tested in simulation and experimentally...

  5. Source and level of energy supplementation for yearling cattle fed ammoniated hay.

    Science.gov (United States)

    Royes, J B; Brown, W F; Martin, F G; Bates, D B

    2001-05-01

    Brahman x British crossbred steers were used in growth and digestion trials to evaluate the response of source (corn, sugar cane molasses, or soybean hulls) and feeding rate (0, 1.4, or 2.8 kg DM per steer daily in the growth trials; 0, 15, or 30% of the ration DM in the digestion trial) of energy supplementation in cattle fed ammoniated (4% of forage DM) stargrass (Cynodon nlemfuensis Vanderyst var. nlemfuensis) hay. Cattle on all treatments were fed 0.5 kg cottonseed meal daily. In the growth trials, steers grazed dormant bahiagrass (Paspalum notatum) pasture. Increasing the levels of supplementation decreased hay intake but increased total dietary intake for all diets (P hemicellulose digestibility. Apparent OM digestibility of all diets increased linearly (P = 0.02) as the level of supplementation increased. Apparent NDF and ADF digestibility decreased (P sources. PMID:11374553

  6. Urban NH3 levels and sources in six major Spanish cities.

    Science.gov (United States)

    Reche, Cristina; Viana, Mar; Karanasiou, Angeliki; Cusack, Michael; Alastuey, Andrés; Artiñano, Begoña; Revuelta, M Aranzazu; López-Mahía, Purificación; Blanco-Heras, Gustavo; Rodríguez, Sergio; Sánchez de la Campa, Ana M; Fernández-Camacho, Rocío; González-Castanedo, Yolanda; Mantilla, Enrique; Tang, Y Sim; Querol, Xavier

    2015-01-01

    A detailed spatial and temporal assessment of urban NH3 levels and potential emission sources was made with passive samplers in six major Spanish cities (Barcelona, Madrid, A Coruña, Huelva, Santa Cruz de Tenerife and Valencia). Measurements were conducted during two different periods (winter-autumn and spring-summer) in each city. Barcelona showed the clearest spatial pattern, with the highest concentrations in the old city centre, an area characterised by a high population density and a dense urban architecture. The variability in NH3 concentrations did not follow a common seasonal pattern across the different cities. The relationship of urban NH3 with SO2 and NOX allowed concluding on the causes responsible for the variations in NH3 levels between measurement periods observed in Barcelona, Huelva and Madrid. However, the factors governing the variations in A Coruña, Valencia and Santa Cruz de Tenerife are still not fully understood. This study identified a broad variability in NH3 concentrations at the city-scale, and it confirms that NH3 sources in Spanish urban environments are vehicular traffic, biological sources (e.g. garbage containers), wastewater treatment plants, solid waste treatment plants and industry. The importance of NH3 monitoring in urban environments relies on its role as a precursor of secondary inorganic species and therefore PMX. Further research should be addressed in order to establish criteria to develop and implement mitigation strategies for cities, and to include urban NH3 sources in the emission inventories. PMID:25194477

  7. Are Occlusal Characteristics, Headache, Parafunctional Habits and Clicking Sounds Associated with the Signs and Symptoms of Temporomandibular Disorder in Adolescents?

    Science.gov (United States)

    Lauriti, Leandro; Motta, Lara Jansiski; Silva, Paula Fernanda da Costa; Leal de Godoy, Camila Haddad; Alfaya, Thays Almeida; Fernandes, Kristianne Porta Santos; Mesquita-Ferrari, Raquel Agnelli; Bussadori, Sandra Kalil

    2013-01-01

    [Purpose] To assess the association between the oclusal characteristics, headache, parafunctional habits and clicking sounds and signs/symptoms of TMD in adolescents. [Subjects] Adolescents between 14 and 18 years of age. [Methods] The participants were evaluated using the Helkimo Index and a clinical examination to track clicking sounds, parafunctional habits and other signs/symptoms of temporomandibular disorder (TMD). Subjects were classified according to the presence or absence of headache, type of occlusion, facial pattern and type of bite. In statistical analyse we used the chi-square test and Fisher's exact test, with a level of significance of 5%. [Results] The sample was made up of 81 adolescents with a mean age of 15.64 years; 51.9% were male. The prevalence of signals/symptoms of TMD was 74.1%, predominantly affecting females. Signals/symptoms of TMD were significantly associated with clicking sounds, headache and nail biting. No associations were found between signals/symptoms of TMD and angle classification, type of bite and facial pattern. [Conclusion] Headache is one of the most closely associated symptoms of TMD. Clicking sounds were found in the majority of cases. Therefore, the sum of two or more factors may be necessary for the onset and perpetuation of TMD. PMID:24259787

  8. Decoration of silk fibroin by click chemistry for biomedical application.

    Science.gov (United States)

    Zhao, Hongshi; Heusler, Eva; Jones, Gabriel; Li, Linhao; Werner, Vera; Germershaus, Oliver; Ritzer, Jennifer; Luehmann, Tessa; Meinel, Lorenz

    2014-06-01

    Silkfibroin (SF) has an excellent biocompatibility and its remarkable structure translates into exciting mechanical properties rendering this biomaterial particularly fascinating for biomedical application. To further boost the material's biological/preclinical impact, SF is decorated with biologics, typically by carbodiimide/N-hydroxysuccinimide coupling (EDC/NHS). For biomedical application, this chemistry challenges the product risk profile due to the formation of covalent aggregates, particularly when decoration is with biologics occurring naturally in humans as these aggregates may prime for autoimmunity. Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAC; click chemistry) provides the necessary specificity to avoid such intermolecular, covalent aggregates. We present a blueprint outlining the necessary chemistry rendering SF compatible with CuAAC and with a particular focus on structural consequences. For that, the number of SF carboxyl groups (carboxyl-SF; required for EDC/NHS chemistry) or azido groups (azido-SF; required for click chemistry) was tailored by means of diazonium coupling of the SF tyrosine residues. Structural impact on SF and decorated SF was characterized by Fourier transform infrared spectroscopy (FTIR). The click chemistry yielded a better controlled product as compared to the EDC/NHS chemistry with no formation of inter- and intramolecular crosslinks as demonstrated for SF decorated with fluorescent model compounds or a biologic, fibroblast growth factor 2 (FGF2), respectively. In conclusion, SF can readily be translated into a scaffold compatible with click chemistry yielding decorated products with a better risk profile for biomedical application. PMID:24576682

  9. "Click & seed" approach to the biomimetic modification of polymers

    Czech Academy of Sciences Publication Activity Database

    Proks, Vladimír; Jaroš, J.; Pop-Georgievski, Ognen; Popelka, Štěpán; Kučka, Jan; Hampl, A.; Dvořák, P.; Rypáček, František

    Tampere : Tampere University of Technology, 2010. s. 3718. [European Conference on Biomaterials /23./. 11.09.2010-15.09.2010, Tampere] R&D Projects: GA AV ČR KJB400500904 Institutional research plan: CEZ:AV0Z40500505 Keywords : polydopamine * click chemistry Subject RIV: CD - Macromolecular Chemistry

  10. Click and seed approach to the biomimetic modification of polymers

    Czech Academy of Sciences Publication Activity Database

    Proks, Vladimír; Jaroš, J.; Pop-Georgievski, Ognen; Popelka, Štěpán; Hampl, A.; Dvořák, P.; Rypáček, František

    Galway : TERMIS, 2010. s. 493. ISBN 978-0-9564492-0-7. [TERMIS-EU Conference. 13.06.2010-17.06.2010, Galway] R&D Projects: GA AV ČR KJB400500801 Institutional research plan: CEZ:AV0Z40500505 Keywords : polydopamine * click chemistry * polyethyleneoxide Subject RIV: CD - Macromolecular Chemistry

  11. "Click & seed" approach to the biomimetic modification of material surfaces

    Czech Academy of Sciences Publication Activity Database

    Proks, Vladimír; Jaroš, J.; Pop-Georgievski, Ognen; Kučka, Jan; Popelka, Štěpán; Dvořák, P.; Hampl, A.; Rypáček, František

    Prague : Institute of Macromolecular Chemistry AS CR, 2012. ML4. ISBN 978-80-85009-73-6. [Workshop "Career in Polymers" /4./. 29.06.2012-30.06.2012, Prague] Institutional research plan: CEZ:AV0Z40500505 Institutional support: RVO:61389013 Keywords : bioactive surfaces * click and seed Subject RIV: CD - Macromolecular Chemistry

  12. Efficient One-click Browsing of Large Trajectory Sets

    DEFF Research Database (Denmark)

    Krogh, Benjamin Bjerre; Andersen, Ove; Lewis-Kelham, Edwin;

    2014-01-01

    presents a novel query type called sheaf, where users can browse trajectory data sets using a single mouse click. Sheaves are very versatile and can be used for location-based advertising, travel-time analysis, intersection analysis, and reachability analysis (isochrones). A novel in-memory trajectory...

  13. Phonetic reduction of clicks – Evidence from Nǀuu

    DEFF Research Database (Denmark)

    Marquard, Carina; Niebuhr, Oliver; Witzlack-Makarevich, Alena

    2015-01-01

    Based on spontaneous speech data of the Tuu language Nǀuu, we used the cross-linguistically established domain-initial strengthening concept in order to examine, if and in which way clicks are subject to speech reduction (lenition) in relation to a reference sample of plosives. Results of combine...

  14. Synthesis of Phenyl-Adducted Cyclodextrin through the Click Reaction

    Science.gov (United States)

    A new derivative of ß-cyclodextrin (CD) has been made incorporating the phenyl group through the use of click reaction. The resulting product exhibits a self-association phenomenon through the formation of inclusion compound between the phenyl group and CD. The product has been characterized by 1H...

  15. Throat clicking as the initial symptom of Parkinson's disease.

    Science.gov (United States)

    Iyer, Sanjay S; Morgan, John C; Glover, Andrea L; Sethi, Kapil D

    2005-10-01

    The presenting manifestations of Parkinson's disease (PD) are variable, but a majority of patients note tremor as the initial symptom. Others complain of slowing of movements, loss of dexterity, fatigue, or changes in handwriting as initial symptoms. We describe a patient who developed an unusual clicking sound emanating from his throat as the initial manifestation of PD. PMID:16001408

  16. Making It CLICK: Planning, Creating, and Using CPCC Libraries' Logo

    Science.gov (United States)

    Moore, Gena

    2005-01-01

    The Central Piedmont Community College Libraries have been successful in creating positive expectations from the CPCC community by connecting an official library logo with quality library service. The creation of the CPCC Libraries' logo CLICK was a process that spanned several months. A history of this process details the meetings and design work…

  17. N-PEG´ylation of chitosan via "click chemistry" reactions

    Czech Academy of Sciences Publication Activity Database

    Kulbokaite, R.; Ciuta, G.; Netopilík, Miloš; Makuška, R.

    2009-01-01

    Roč. 69, č. 10 (2009), s. 771-778. ISSN 1381-5148 R&D Projects: GA ČR GA203/07/0659 Institutional research plan: CEZ:AV0Z40500505 Keywords : chitosan * poly(ethylene glycol) * click chemistry Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.461, year: 2009

  18. Blue and fin whale call source levels and propagation range in the Southern Ocean

    OpenAIRE

    Sirovic, Anna; Hildebrand, John A.; Wiggins, Sean

    2007-01-01

    Blue (Balaenoptera musculus) and fin whales (B. physalus) produce high-intensity, low-frequency calls, which probably function for communication during mating and feeding. The source levels of blue and fin whale calls off the Western Antarctic Peninsula were calculated using recordings made with calibrated, bottom-moored hydrophones. Blue whales were located up to a range of 200 km using hyperbolic localization and time difference of arrival. The distance to fin whales, estimated using multi...

  19. Household Air Pollution: Sources and Exposure Levels to Fine Particulate Matter in Nairobi Slums

    Directory of Open Access Journals (Sweden)

    Kanyiva Muindi

    2016-07-01

    Full Text Available With 2.8 billion biomass users globally, household air pollution remains a public health threat in many low- and middle-income countries. However, little evidence on pollution levels and health effects exists in low-income settings, especially slums. This study assesses the levels and sources of household air pollution in the urban slums of Nairobi. This cross-sectional study was embedded in a prospective cohort of pregnant women living in two slum areas—Korogocho and Viwandani—in Nairobi. Data on fuel and stove types and ventilation use come from 1058 households, while air quality data based on the particulate matters (PM2.5 level were collected in a sub-sample of 72 households using the DustTrak™ II Model 8532 monitor. We measured PM2.5 levels mainly during daytime and using sources of indoor air pollutions. The majority of the households used kerosene (69.7% as a cooking fuel. In households where air quality was monitored, the mean PM2.5 levels were high and varied widely, especially during the evenings (124.6 µg/m3 SD: 372.7 in Korogocho and 82.2 µg/m3 SD: 249.9 in Viwandani, and in households using charcoal (126.5 µg/m3 SD: 434.7 in Korogocho and 75.7 µg/m3 SD: 323.0 in Viwandani. Overall, the mean PM2.5 levels measured within homes at both sites (Korogocho = 108.9 µg/m3 SD: 371.2; Viwandani = 59.3 µg/m3 SD: 234.1 were high. Residents of the two slums are exposed to high levels of PM2.5 in their homes. We recommend interventions, especially those focusing on clean cookstoves and lighting fuels to mitigate indoor levels of fine particles.

  20. Intense ultrasonic clicks from echolocating toothed whales do not elicit anti-predator responses or debilitate the squid Loligo pealeii

    OpenAIRE

    Wilson, Maria; Hanlon, Roger T.; Tyack, Peter L; Madsen, Peter T.

    2007-01-01

    Toothed whales use intense ultrasonic clicks to echolocate prey and it has been hypothesized that they also acoustically debilitate their prey with these intense sound pulses to facilitate capture. Cephalopods are an important food source for toothed whales, and there has probably been an evolutionary selection pressure on cephalopods to develop a mechanism for detecting and evading sound-emitting toothed whale predators. Ultrasonic detection has evolved in some insects to avoid echolocating ...

  1. Modeling effectiveness of gradual increases in source level to mitigate effects of sonar on marine mammals.

    Science.gov (United States)

    Von Benda-Beckmann, Alexander M; Wensveen, Paul J; Kvadsheim, Petter H; Lam, Frans-Peter A; Miller, Patrick J O; Tyack, Peter L; Ainslie, Michael A

    2014-02-01

    Ramp-up or soft-start procedures (i.e., gradual increase in the source level) are used to mitigate the effect of sonar sound on marine mammals, although no one to date has tested whether ramp-up procedures are effective at reducing the effect of sound on marine mammals. We investigated the effectiveness of ramp-up procedures in reducing the area within which changes in hearing thresholds can occur. We modeled the level of sound killer whales (Orcinus orca) were exposed to from a generic sonar operation preceded by different ramp-up schemes. In our model, ramp-up procedures reduced the risk of killer whales receiving sounds of sufficient intensity to affect their hearing. The effectiveness of the ramp-up procedure depended strongly on the assumed response threshold and differed with ramp-up duration, although extending the duration of the ramp up beyond 5 min did not add much to its predicted mitigating effect. The main factors that limited effectiveness of ramp up in a typical antisubmarine warfare scenario were high source level, rapid moving sonar source, and long silences between consecutive sonar transmissions. Our exposure modeling approach can be used to evaluate and optimize mitigation procedures. PMID:24471782

  2. Alternative high-level radiation sources for sewage and waste-water treatment

    International Nuclear Information System (INIS)

    The choice of an energy source for the radiation treatment of waste-water or sludge is between an electron accelerator or a gamma-ray source of radioactive cobalt or caesium. A number of factors will affect the ultimate choice and the potential future adoption of radiation as a treatment technique. The present and future availability of radioactive sources of cobalt and caesium is closely linked to the rate of nuclear power development and the assumption by uranium fuel reprocessors of a role as radioactive caesium suppliers. Accelerators are industrial machines which could be readily produced to meet any conceivable market demand. For energy sources in the 20-30 kW range, electron accelerators appear to have an initial capital cost advantage of about seven and an operating cost advantage of two. While radioisotope sources are inherently more reliable, accelerators at voltages to 3 MeV have achieved a reliability level adequate to meet the demands of essentially continuous operations with moderate maintenance requirements. The application of either energy source to waste-water treatment will be significantly influenced by considerations of the relative penetration capability, energy density and physical geometrical constraints of each option. The greater range of the gamma rays and the lower energy density of the isotopic sources permit irradiation of a variety of target geometrics. The low penetration of electrons and the high-energy density of accelerators limit application of the latter to targets presented as thin films of several centimetres thickness. Any potential use of radiation must proceed from a clear definition of process objectives and critical comparison of the radiation energy options for that specific objective. (Author)

  3. Source identification and budget analysis on elevated levels of formaldehyde within ship plumes: a photochemical/dynamic model analysis

    OpenAIRE

    C. H. Song; Kim, H. S.; von Glasow, R.; Brimblecombe, P.; Kim, J; R. J. Park; Woo, J. H.

    2010-01-01

    Elevated levels of formaldehyde (HCHO) along the ship corridors have been observed by satellite sensors, such as ESA/ERS-2 GOME (Global Ozone Monitoring Experiment), and were also predicted by global 3-D chemistry-transport models. In this study, three likely sources of the elevated HCHO levels were investigated to identify the detailed sources and examine the contributions of the sources (budget) of the elevated levels of HCHO in the ship corridors using a newly-developed ship-plume pho...

  4. Levels and potential sources of atmospheric organochlorine pesticides at Korea background sites

    Science.gov (United States)

    Jin, Guang-Zhu; Kim, Sang-Min; Lee, Su-Yeong; Park, Jin-Soo; Kim, Dong-Hoon; Lee, Min-Jin; Sim, Ki-Tae; Kang, Hak-Gu; Kim, Il-Gyu; Shin, Sun-Kyoung; Seok, Kwang-Seol; Hwang, Seung-Ryul

    2013-04-01

    Data are presented for 11 organochlorine pesticides (OCPs) measured by high volume air samplers at three background sites (monthly for one site, seasonally for two sites) in South Korea during June 2008 and December 2009, and levels, seasonal variations and potential sources of high levels of OCPs and impact of long-range transport (LRT) were discussed. Geometric mean (GM) concentrations of OCPs in air samples (pg m-3) were highest for HCB (80, 15.0-256), HCH (71, 10.8-547), a currently used pesticide, DDT (3.50, ND-56.5), and Chlordane (1.15, ND-10.5). Other chemicals regularly detected included, Heptachlor (0.41, ND-2.59), Drins (0.61, ND-4.36) and Mirex (0.04, ND-0.78). Seasonal variation of OCPs was featured by higher concentrations in summer and lower in winter period. This could be associated with their temperature-driven re-volatilization from historical source and recent application of some OCPs (such as dicofol, HCH etc). Ratios of specific OCPs isomers suggest that dominant source of air HCHs in Korea background sites is technical HCH with a little input of lindane in recent time, and dominant source of air DDT is old and used technical DDT with a little bit of dicofol type DDT, and current air chlordane in Korean background sites mainly come from the source of historically used chlordane. The results from this study will provide comparable and scientifically sound data of OCP in background air and will contribute to further long-term POPs monitoring program in East Asia.

  5. Assessing the sources of high fecal coliform levels at an urban tropical beach

    Directory of Open Access Journals (Sweden)

    Aline Mendonça Cavalcante Davino

    2015-01-01

    Full Text Available Recreational water quality is commonly assessed by microbial indicators such as fecal coliforms. Maceió is the capital of Alagoas state, located in tropical northeastern Brazil. Its beaches are considered as the most beautiful urban beaches in the country. Jatiúca Beach in Maceió was found to be unsuitable for bathing continuously during the year of 2011. The same level of contamination was not observed in surrounding beaches. The aim of this study was to initiate the search for the sources of these high coliform levels, so that contamination can be eventually mitigated. We performed a retrospective analysis of historical results of fecal coliform concentrations from 2006 to 2012 at five monitoring stations located in the study region. Results showed that Jatiúca Beach consistently presented the worst quality among the studied beaches. A field survey was conducted to identify existing point and non-point sources of pollution in the area. Monitoring in the vicinity of Jatiúca was spatially intensified. Fecal coliform concentrations were categorized according to tide range and tide stage. A storm drain located in northern Jatiúca was identified as the main point source of the contamination. However, fecal coliform concentrations at Jatiúca were high during high tides and spring tides even when this point source was inactive (no rainfall. We hypothesize that high fecal coliform levels in Jatiúca Beach may also be caused by aquifer contamination or, more likely, from tide washing of contaminated sand. Both of these hypotheses will be further investigated.

  6. Wing-click sounds of Heliconius cydno alithea (Nymphalidae: Heliconiinae) butterflies

    Science.gov (United States)

    Wild Heliconius cydno Doubleday females were observed producing short trains of 3-10 wing-clicks at the rate of about 10 clicks/s. Sounds were recorded at roosting time and during the day in encounters between conspecifics. The individual clicks had a mean duration of 1.48 ms and a broad frequency...

  7. Ambient levels of carbonyl compounds and their sources in Guangzhou, China

    Science.gov (United States)

    Feng, Yanli; Wen, Sheng; Chen, Yingjun; Wang, Xinming; Lü, Huixiong; Bi, Xinhui; Sheng, Guoying; Fu, Jiamo

    Ambient levels of carbonyl compounds and their possible sources, vehicular exhaust and cooking exhaust, were studied at seven places in Guangzhou, including five districts (a residential area, an industrial area, a botanical garden, a downtown area and a semi-rural area), a bus station and a restaurant during the period of June-September 2003. Nineteen carbonyl compounds were identified in the ambient air, of which acetone was the most abundant carbonyl, followed by formaldehyde and acetaldehyde. Only little changes were found in carbonyl concentration levels in the five different districts because of their dispersion and mixture in the atmosphere in summer. The lower correlations between the carbonyls' concentrations might result from the mixture of carbonyls derived from different sources, including strong photochemical reactions at noon in summer. Formaldehyde and acetaldehyde were the main carbonyls in bus station, while straight-chain carbonyls were comparatively abundant in cooking exhaust. Besides vehicular exhaust, cooking might be another major source of carbonyl compounds in Guangzhou City, especially for high molecular weight carbonyls.

  8. Effect of source and level of potash on yield and quality of potato tubers

    International Nuclear Information System (INIS)

    Field experiments were conducted for two consecutive seasons at NARC potato research area Islamabad, Pakistan, to study comparative effect of source, levels and methods of K fertilization on yield and quality of potato produce. Nitrogen and phosphorus were applied at 250 and 125 kg ha/sup -1/, respectively whereas three K/sub 2/O levels, 0, 150 and 225 kg ha/sup -1/ from two sources of potash (SOP and MOP) were tested. Potassium was also applied as foliar spray at 1% K/sub 2/O solution at 30, 45 and 60 days after germination (DAG) and soil was also amended by 150 kg K/sub 2/O ha/sup -1/. A significant increase in tuber yield with K application at 150 kg ha/sup -1/ as K/sub 2/O from both the K sources over NP treatment was recorded. Increase in tuber yield with K/sub 2/O at the rate of 225 kg ha/sup -1/ was statistically nonsignificant compared to 150 kg K/sub 2/O ha/sup -1/. A positive interaction between soil applied P and K with N in plant system was observed. Potassium treatments not only increased K concentration but also affected N and P contents in potato tubers. The quality parameters like dry matter, specific gravity, starch contents, vitamin-C and ash contents were also affected with P and K fertilization. (author)

  9. Analysis of source term modeling for low-level radioactive waste performance assessments

    International Nuclear Information System (INIS)

    Site-specific radiological performance assessments are required for the disposal of low-level radioactive waste (LLW) at both commercial and US Department of Energy facilities. This work explores source term modeling of LLW disposal facilities by using two state-of-the-art computer codes, SOURCEI and SOURCE2. An overview of the performance assessment methodology is presented, and the basic processes modeled in the SOURCE1 and SOURCE2 codes are described. Comparisons are made between the two advective models for a variety of radionuclides, transport parameters, and waste-disposal technologies. These comparisons show that, in general, the zero-order model predicts undecayed cumulative fractions leached that are slightly greater than or equal to those of the first-order model. For long-lived radionuclides, results from the two models eventually reach the same value. By contrast, for short-lived radionuclides, the zero-order model predicts a slightly higher undecayed cumulative fraction leached than does the first-order model. A new methodology, based on sensitivity and uncertainty analyses, is developed for predicting intruder scenarios. This method is demonstrated for 137Cs in a tumulus-type disposal facility. The sensitivity and uncertainty analyses incorporate input-parameter uncertainty into the evaluation of a potential time of intrusion and the remaining radionuclide inventory. Finally, conclusions from this study are presented, and recommendations for continuing work are made

  10. Test method for position of accelerate grid of megawatt level high current ion source

    International Nuclear Information System (INIS)

    Background: Accelerate grid for producing several tens of MW ion beams is a critical component of the megawatt level high current ion source for the high power neutral beam injection, Purpose: To measure and analyze the position of accelerate grid. Methods: Taking the exit grid module of EAST-NBI high current ion source as the measurement object, the observation point coordinates of accelerate grid rail's actual axis are obtained by using 3 quadrant points sampling method and the point coordinates are analyzed by using MATLAB optimal function. Results: The position error that tallies with minimum zone and the distribution regularities of accelerate grid rails are obtained. Conclusions: This method has simple and stable course of evaluating, can realize automatic measurement and provide the basis for improving and finalizing the grid module's processing technic. (authors)

  11. An Analytical Simple Formula for the Ground Level Concentration from a Point Source

    Directory of Open Access Journals (Sweden)

    Daniela Buske

    2011-03-01

    Full Text Available The Advection-Diffusion Equation is solved for a constant pollutant emission from a point-like source placed inside an unstable Atmospheric Boundary Layer. The solution is obtained adopting the novel analytical approach: Generalized Integral Laplace Transform Technique. The concentration solution of the equation is expressed through an infinite series expansion. After setting a realistic scenario through the wind and diffusivity parameterizations, the Ground Level Concentration (GLC is determined, and an explicit approximate expression is provided for it, allowing an analytically simple expression for the position and value of the maximum. Remarks arise regarding the ability to express value and position of the GLC as explicit functions of the parameters defining the Atmospheric Boundary Layer scenario and the source height.

  12. Using click chemistry to modify block copolymers and their morphologies

    Science.gov (United States)

    Wollbold, Johannes

    Microphase separated block copolymers (BCPs) are emerging as promising templates and scaffolds for the fabrication of nanostructured materials. To achieve the desired nanostructures, it is necessary to establish convenient approaches to control the morphology of BCPs. It remains challenging to induce morphological transitions of BCPs via external fields. Click chemistry, especially alkyne/azide click chemistry, has been widely used to synthesize novel functionalized materials. Here, we demonstrate that alkyne/azide click chemistry can be used as an efficient approach to chemically modify BCPs and therefore induce morphological transitions. Alkyne-functionalized diblock copolymers (di-BCPs) poly(ethylene oxide)- block-poly(n-butyl methacrylate-random-propargyl methacrylate) (PEO-b-P(nBMA-r-PgMA)) have been successfully synthesized. When the di-BCP is blended with an azide additive Rhodamine B azide and annealed at elevated temperatures, click reaction occurs between the two components. With the Rhodamine B structure attached to the polymer backbone, the di-BCP shows dramatic change in the interactions between the two blocks and the volume fraction of each block. As a result, morphological transitions, such as disorder-to-order transitions (DOTs) and order-to-order transitions (OOTs), are observed. The reaction kinetics and morphology evolution during the click chemistry induced DOTs have been investigated by in-situ and ex-situ characterizations, and fast kinetics properties are observed. Microphase separated morphologies after the DOTs or OOTs are dictated by the composition of neat di-BCPs and the mole ratio between the alkyne and azide groups. The DOTs of PEO-b-P(nBMA-r-PgMA) di-BCPs induced by alkyne/azide click chemistry have also been achieved in thin film geometries, with comparable kinetics to bulk samples. The orientation of the microdomains is dependent on the grafting density of Rhodamine B structure as well as film thickness. At higher grafting densities

  13. Meta-analysis on Methane Mitigating Properties of Saponin-rich Sources in the Rumen: Influence of Addition Levels and Plant Sources.

    Science.gov (United States)

    Jayanegara, Anuraga; Wina, Elizabeth; Takahashi, Junichi

    2014-10-01

    Saponins have been considered as promising natural substances for mitigating methane emissions from ruminants. However, studies reported that addition of saponin-rich sources often arrived at contrasting results, i.e. either it decreased methane or it did not. The aim of the present study was to assess ruminal methane emissions through a meta-analytical approach of integrating related studies from published papers which described various levels of different saponin-rich sources being added to ruminant feed. A database was constructed from published literature reporting the addition of saponin-rich sources at various levels and then monitoring ruminal methane emissions in vitro. Accordingly, levels of saponin-rich source additions as well as different saponin sources were specified in the database. Apart from methane, other related rumen fermentation parameters were also included in the database, i.e. organic matter digestibility, gas production, pH, ammonia concentration, short-chain fatty acid profiles and protozoal count. A total of 23 studies comprised of 89 data points met the inclusion criteria. The data obtained were subsequently subjected to a statistical meta-analysis based on mixed model methodology. Accordingly, different studies were treated as random effects whereas levels of saponin-rich source additions or different saponin sources were considered as fixed effects. Model statistics used were p-value and root mean square error. Results showed that an addition of increasing levels of a saponin-rich source decreased methane emission per unit of substrate incubated as well as per unit of total gas produced (psources, all saponin sources, i.e. quillaja, tea and yucca saponins produced less methane per unit of total gas than that of control (psources in mitigating methane was yucca>tea>quillaja, statistically they did not differ each other. It can be concluded that methane mitigating properties of saponins in the rumen are level- and source-dependent. PMID

  14. Comparison of three-phase three-level voltage source inverter with intermediate dc–dc boost converter and quasi-Z-source inverter

    DEFF Research Database (Denmark)

    Panfilov, Dmitry; Husev, Oleksandr; Blaabjerg, Frede; Zakis, Janis; Khandakji, Kamal

    2016-01-01

    This study compares a three-phase three-level voltage source inverter with an intermediate dc-dc boost converter and a quasi-Z-source inverter in terms of passive elements values and dimensions, semiconductor stresses, and overall efficiency. A comparative analysis was conducted with relative...

  15. Low-level radioactive waste source terms for the 1992 integrated data base

    International Nuclear Information System (INIS)

    This technical manual presents updated generic source terms (i.e., unitized amounts and radionuclide compositions) which have been developed for use in the Integrated Data Base (IDB) Program of the U.S. Department of Energy (DOE). These source terms were used in the IDB annual report, Integrated Data Base for 1992: Spent Fuel and Radioactive Waste Inventories, Projections, and Characteristics, DOE/RW-0006, Rev. 8, October 1992. They are useful as a basis for projecting future amounts (volume and radioactivity) of low-level radioactive waste (LLW) shipped for disposal at commercial burial grounds or sent for storage at DOE solid-waste sites. Commercial fuel cycle LLW categories include boiling-water reactor, pressurized-water reactor, fuel fabrication, and uranium hexafluoride (UF6) conversion. Commercial nonfuel cycle LLW includes institutional/industrial (I/I) waste. The LLW from DOE operations is category as uranium/thorium fission product, induced activity, tritium, alpha, and open-quotes otherclose quotes. Fuel cycle commercial LLW source terms are normalized on the basis of net electrical output [MW(e)-year], except for UF6 conversion, which is normalized on the basis of heavy metal requirement [metric tons of initial heavy metal ]. The nonfuel cycle commercial LLW source term is normalized on the basis of volume (cubic meters) and radioactivity (curies) for each subclass within the I/I category. The DOE LLW is normalized in a manner similar to that for commercial I/I waste. The revised source terms are based on the best available historical data through 1992

  16. Sea-level constraints on the amplitude and source distribution of Meltwater Pulse 1A

    Science.gov (United States)

    Liu, Jean; Milne, Glenn A.; Kopp, Robert E.; Clark, Peter U.; Shennan, Ian

    2016-02-01

    During the last deglaciation, sea levels rose as ice sheets retreated. This climate transition was punctuated by periods of more intense melting; the largest and most rapid of these--Meltwater Pulse 1A--occurred about 14,500 years ago, with rates of sea-level rise reaching approximately 4 m per century. Such rates of rise suggest ice-sheet instability, but the meltwater sources are poorly constrained, thus limiting our understanding of the causes and impacts of the event. In particular, geophysical modelling studies constrained by tropical sea-level records suggest an Antarctic contribution of more than seven metres, whereas most reconstructions from Antarctica indicate no substantial change in ice-sheet volume around the time of Meltwater Pulse 1A. Here we use a glacial isostatic adjustment model to reinterpret tropical sea-level reconstructions from Barbados, the Sunda Shelf and Tahiti. According to our results, global mean sea-level rise during Meltwater Pulse 1A was between 8.6 and 14.6 m (95% probability). As for the melt partitioning, we find an allowable contribution from Antarctica of either 4.1 to 10.0 m or 0 to 6.9 m (95% probability), using two recent estimates of the contribution from the North American ice sheets. We conclude that with current geologic constraints, the method applied here is unable to support or refute the possibility of a significant Antarctic contribution to Meltwater Pulse 1A.

  17. Spectrometer control subsystem with high level functionality for use at the National Synchrotron Light Source

    International Nuclear Information System (INIS)

    We have developed a subsystem capable of controlling stepping motors in a wide variety of vuv and x-ray spectrometers to be used at the National Sychrotron Light Source. The subsystem is capable of controlling up to 15 motors with encoder readback and ramped acceleration/deceleration. Both absolute and incremental encoders may be used in any mixture. Function commands to the subsystem are communicated via ASCII characters over an asynchronous serial link in a well-defined protocol in decipherable English. Thus the unit can be controlled via write statements in a high-level language. Details of hardware implementation will be presented

  18. Assessing the sources of high fecal coliform levels at an urban tropical beach

    OpenAIRE

    Aline Mendonça Cavalcante Davino; Milena Bandeira de Melo; Roberto Augusto Caffaro Filho

    2015-01-01

    Recreational water quality is commonly assessed by microbial indicators such as fecal coliforms. Maceió is the capital of Alagoas state, located in tropical northeastern Brazil. Its beaches are considered as the most beautiful urban beaches in the country. Jatiúca Beach in Maceió was found to be unsuitable for bathing continuously during the year of 2011. The same level of contamination was not observed in surrounding beaches. The aim of this study was to initiate the search for the sources o...

  19. Greenhouse Gas Emissions from Ground Level Area Sources in Dairy and Cattle Feedyard Operations

    OpenAIRE

    Parnell, Calvin B.; Capareda, Sergio C.; Saqib Mukhtar; Faulkner, William B.; Md Saidul Borhan; Russell McGee

    2011-01-01

    A protocol that consisted of an isolation flux chamber and a portable gas chromatograph was used to directly quantify greenhouse gas (GHG) emissions at a dairy and a feedyard operation in the Texas Panhandle. Field sampling campaigns were performed 5 consecutive days only during daylight hours from 9:00 am to 7:00 pm each day. The objective of this research was to quantify and compare GHG emission rates (ERs) from ground level area sources (GLAS) at dairy and cattle feedyard operations during...

  20. Three-Level AC-DC-AC Z-Source Converter Using Reduced Passive Component Count

    DEFF Research Database (Denmark)

    Loh, Poh Chiang; Gao, Feng; Tan, Pee-Chin;

    2007-01-01

    This paper presents a three-level ac-dc-ac Z-source converter with output voltage buck-boost capability. The converter is implemented by connecting a low cost front-end diode rectifier to a neutral-point-clamped inverter through a single X-shaped LC impedance network. The inverter is controlled to...... low cost alternative to sensitive applications that need to ride-through frequent input voltage sags. For confirming the converter performance, experimental testing using a constructed laboratory prototype is performed with its captured results presented in a later section of the paper....

  1. Three-Level AC-DC-AC Z-Source Converter Using Reduced Passive Component Count

    DEFF Research Database (Denmark)

    Loh, Poh Chiang; Gao, Feng; Tan, Pee-Chin;

    2009-01-01

    This paper presents a three-level ac-dc-ac Z-source converter with output voltage buck-boost capability. The converter is implemented by connecting a low-cost front-end diode rectifier to a neutral-point-clamped inverter through a single X-shaped LC impedance network. The inverter is controlled to...... semiconductor commutations, and hence, no increase in switching losses. The proposed converter therefore offers a low-cost alternative to applications that need to ride through frequent input voltage sags. For confirming the converter performance, experimental testing using a constructed laboratory prototype is...

  2. Estimation Of Source Term For Indian PHWRS (KAPS) As Part Of PSA Level-2 Study

    International Nuclear Information System (INIS)

    Source Term (ST) is generally known as the amount of the radio-nuclides(fission products along with activation and Actinides) that can be released from a nuclear power plant in an accident. The ST can be more accurately defined as the quantity, timing, composition, chemical and physical form of radio-nuclides. The amount of radio-nuclides is a fundamental parameter to estimate the consequences of an accident on individuals and environment. A quantitative estimation of the ST is of importance for assessing the effectiveness of safety design features and for the planning of post accident emergency measures in the public domain. The PSA Level-1 study for IPHWRs(KAPS) was completed in 2002 and an attempt was made to estimate the ST for different accident scenarios as part of PSA Level-2 study. The scope of this paper is limited to estimate the ST for Indian Pressurized Heavy Water Reactors (IPHWRs) in accident conditions. (authors)

  3. Nanofabrication Yields. Hybridization and Click-Fixation of Polycyclic DNA Nanoassemblies

    KAUST Repository

    Lundberg, Erik P.

    2011-09-27

    We demonstrate the stepwise assembly of a fully addressable polycyclic DNA hexagon nanonetwork for the preparation of a four-ring system, one of the biggest networks yet constructed from tripodal building blocks. We find that the yield exhibits a distinct upper level <100%, a fundamental problem of thermodynamic DNA assembly that appears to have been overlooked in the DNA nanotechnology literature. A simplistic model based on a single step-yield parameter y can quantitatively describe the total yield of DNA assemblies in one-pot reactions as Y = yduplex n, with n the number of hybridization steps. Experimental errors introducing deviations from perfect stoichiometry and the thermodynamics of hybridization equilibria contribute to decreasing the value of yduplex (on average y = 0.96 for our 10 base pair hybridization). For the four-ring system (n = 31), the total yield is thus less than 30%, which is clearly unsatisfactory if bigger nanoconstructs of this class are to be designed. Therefore, we introduced site-specific click chemistry for making and purifying robust building blocks for future modular constructs of larger assemblies. Although the present yield of this robust module was only about 10%, it demonstrates a first step toward a general fabrication approach. Interestingly, we find that the click yields follow quantitatively a binomial distribution, the predictability of which indicates the usefulness of preparing pools of pure and robust building blocks in this way. The binomial behavior indicates that there is no interference between the six simultaneous click reactions but that step-yield limiting factors such as topological constraints and Cu(I) catalyst concentration are local and independent. © 2011 American Chemical Society.

  4. Atmospheric polychlorinated biphenyls in Indian cities: Levels, emission sources and toxicity equivalents

    International Nuclear Information System (INIS)

    Atmospheric concentration of Polychlorinated biphenyls (PCBs) were measured on diurnal basis by active air sampling during Dec 2006 to Feb 2007 in seven major cities from the northern (New Delhi and Agra), eastern (Kolkata), western (Mumbai and Goa) and southern (Chennai and Bangalore) parts of India. Average concentration of Σ25PCBs in the Indian atmosphere was 4460 (±2200) pg/m−3 with a dominance of congeners with 4–7 chlorine atoms. Model results (HYSPLIT, FLEXPART) indicate that the source areas are likely confined to local or regional proximity. Results from the FLEXPART model show that existing emission inventories cannot explain the high concentrations observed for PCB-28. Electronic waste, ship breaking activities and dumped solid waste are attributed as the possible sources of PCBs in India. Σ25PCB concentrations for each city showed significant linear correlation with Toxicity equivalence (TEQ) and Neurotoxic equivalence (NEQ) values. Highlights: •Unlike decreasing trend of PCBs in United States and European countries, high levels of PCBs remain in the Indian atmosphere. •Existing emission inventories cannot explain the high PCB concentrations in Indian atmosphere. •Electronic waste recycling, ship dismantling and open burning of municipal solid waste are implicated as potential sources. -- Measurement of atmospheric Polychlorinated biphenyls in seven major Indian cities

  5. Effect of protein level and protein source on zinc absorption in humans

    International Nuclear Information System (INIS)

    The effect of increasing levels of various protein sources on zinc absorption from a legume-based meal was studied in humans with the use of a radionuclide technique. The meals were extrinsically labelled with 65Zn and absorption was determined from measurements of the whole-body retention of the isotope. The mean fractional zinc absorption for the 13 meals was 24.7 +/- 6.9% and was only influenced by the protein content of the meal to a limited extent (r = 0.45). However, the amount of zinc absorbed from the meals was strongly correlated with both the protein (r = 0.85) and zinc content (r = 0.86): 5.9 +/- 1.7 mumol of zinc was absorbed from the basal bean meal which had the lowest protein content; the addition of low zinc chicken doubled the protein content and increased zinc absorption to 10.3 +/- 2.0 mumol; the addition of zinc-rich beef also doubled the protein content, however, zinc absorption was increased to 15.9 +/- 4.7 mumol. It is concluded that the zinc content of the main protein source of the diet determines the amount of zinc absorbed to a large extent. However, relatively small amounts of animal protein can significantly improve the value of a legume-based meal as a source of zinc

  6. The impact of NRC guidance on concentration averaging on low level waste sealed source disposal - 11424

    Energy Technology Data Exchange (ETDEWEB)

    Whitworth, Julia [Los Alamos National Laboratory; Stewart, Bill [Los Alamos National Laboratory; Cuthbertson, Abigail [DOE

    2011-01-20

    As part of its ongoing efforts to revise the Nuclear Regulatory Commission's (NRC) current position on blending to be risk-informed and performance based and its current review of the low-level waste classification codified in 10 CFR 61.55, the Nuclear Regulatory Commission (NRC) has stated that it may review the 1995 'Branch Technical Position on Concentration Averaging and Encapsulation' (BTP), which is still commonly used today. Such a review will have timely advantages, given the lack of commercial disposal availability within the United States for radioactive sealed sources that are in wide beneficial use across the country. The current application of the BTP guidance has resulted in an effective cap on commercial disposal for sources larger than 1.1 TBq (30 Ci). This paper will analyze how the BTP has been implemented with respect to sealed sources, what the implications have been for commercial disposal availability, and whether alternative packaging configurations could be considered for disposal.

  7. COFFEE YIELD AND PHOSPHATE NUTRITION PROVIDED TO PLANTS BY VARIOUS PHOSPHORUS SOURCES AND LEVELS

    Directory of Open Access Journals (Sweden)

    Kaio Gonçalves de Lima Dias

    2015-04-01

    Full Text Available Phosphorus (P is considered one of the nutrients that most limits crop yields, especially in soils with an advanced degree of weathering. To evaluate P dynamics and availability in soil resulting from various P doses and sources and to assess the resulting P content of coffee leaves and the final coffee yield, an experiment was conducted in the municipality of Três Pontas, MG, Brazil, in a Red Argisol (Ultisol area. Fertilization, except for P fertilization, was performed based on the soil analysis results. The annual P doses tested were 0, 75, 150, 300, 450 and 600 kg ha-1 P2O5. Two P sources, simple superphosphate and magnesium thermal phosphate, were evaluated and compared in the study. A physicochemical analysis of the soil and an analysis of leaf dry matter were performed. The available P content in the soil increased as a result of the applications of the two sources. The leaf P levels stabilized at approximately 1.8 and 1.9 g kg-1 for simple superphosphate and magnesium thermal phosphate, respectively, as a result of the application of approximately 300 kg ha-1 P2O5. The coffee responded to P fertilization in the production phase. Averaged over three harvests, the yield per harvest showed gains of 45.3% and 40.3% for simple superphosphate and magnesium thermal phosphate, respectively, with the application of the highest studied dose, 600 kg ha-1 P2O5.

  8. Modified condylotomy versus conventional conservative treatment in painful reciprocal clicking

    DEFF Research Database (Denmark)

    Bakke, Merete; Eriksson, Lars; Thorsen, Niels Max; Sewerin, Ib; Petersson, Arne; Wagner, Aase

    2008-01-01

    conditions were disc displacements with reduction and arthralgia (Research diagnostic criteria for temporomandibular disorders), but based on MRI, one patient had disc displacement without reduction and another had normal disc position. The treatment effect was significantly better and the disorders were......Modified condylotomy may be relevant in severe painful reciprocal clicking of the temporomandibular joint (TMJ) where conservative treatment is insufficient. The effect of the modified condylotomy was analyzed and compared with conventional nonsurgical treatment in a randomized pilot study of eight...

  9. Vestibular hypersensitivity to clicks is characteristic of the Tullio phenomenon

    OpenAIRE

    Colebatch, J; Day, B.; Bronstein, A; Davies, R.; Gresty, M.; Luxon, L; Rothwell, J

    1998-01-01

    OBJECTIVES—The frequency of pathologically reduced click thresholds for vestibular activation was explored in patients with the Tullio phenomenon (sound induced vestibular activation).
METHODS—Seven patients (eight affected ears) with symptoms of oscillopsia and unsteadiness in response to loud external sounds or to the patient's own voice were examined. In all but one patient, vestibular hypersensitivity to sound was confirmed by the fact that eye movements could be produced b...

  10. Reactivity of Biarylazacyclooctynones in Copper-Free Click Chemistry

    OpenAIRE

    Gordon, Chelsea G.; Mackey, Joel L.; Jewett, John C.; Sletten, Ellen M; Houk, K. N.; Bertozzi, Carolyn R.

    2012-01-01

    The 1,3-dipolar cycloaddition of cyclooctynes with azides, also called “copper-free click chemistry”, is a bioorthogonal reaction with widespread applications in biological discovery. The kinetics of this reaction are of paramount importance for studies of dynamic processes, particularly in living subjects. Here we performed a systematic analysis of the effects of strain and electronics on the reactivity of cyclooctynes with azides through both experimental measurements and computational stud...

  11. Grafting of Polycaprolactone on Oxidized Nanocelluloses by Click Chemistry

    OpenAIRE

    Claude Daneault; Sylvain Robert; Khalil Jradi; Abdelhaq Benkaddour

    2013-01-01

    The main objective of this work is the grafting of polycaprolactone diol (PCL) on the surface of oxidized nanocelluloses (ONC) in order to enhance the compatibility between the hydrophilic cellulose nanofibres and the hydrophobic polymer matrix. This grafting was successfully realized with a new strategy known as click chemistry. In this context, the oxidized nanocelluloses bearing alkyl groups (ONC-PR) were prepared by reacting amino groups of propargylamine (PR) with carboxyl groups of ONC....

  12. Recent Advances in Click Chemistry Applied to Dendrimer Synthesis

    OpenAIRE

    Mathieu Arseneault; Caroline Wafer; Jean-François Morin

    2015-01-01

    Dendrimers are monodisperse polymers grown in a fractal manner from a central point. They are poised to become the cornerstone of nanoscale devices in several fields, ranging from biomedicine to light-harvesting. Technical difficulties in obtaining these molecules has slowed their transfer from academia to industry. In 2001, the arrival of the “click chemistry” concept gave the field a major boost. The flagship reaction, a modified Hüisgen cycloaddition, allowed researchers greater freedom in...

  13. Click Chemistry-Mediated Nanosensors for Biochemical Assays

    OpenAIRE

    Chen, Yiping; Xianyu, Yunlei; Wu, Jing; Yin, Binfeng; Jiang, Xingyu

    2016-01-01

    Click chemistry combined with functional nanoparticles have drawn increasing attention in biochemical assays because they are promising in developing biosensors with effective signal transformation/amplification and straightforward signal readout for clinical diagnostic assays. In this review, we focus on the latest advances of biochemical assays based on Cu (I)-catalyzed 1, 3-dipolar cycloaddition of azides and alkynes (CuAAC)-mediated nanosensors, as well as the functionalization of nanopro...

  14. Click- and chirp-evoked human compound action potentials

    OpenAIRE

    Chertoff, Mark; Lichtenhan, Jeffery; Willis, Marie

    2010-01-01

    In the experiments reported here, the amplitude and the latency of human compound action potentials (CAPs) evoked from a chirp stimulus are compared to those evoked from a traditional click stimulus. The chirp stimulus was created with a frequency sweep to compensate for basilar membrane traveling wave delay using the O-Chirp equations from Fobel and Dau [(2004). J. Acoust. Soc. Am. 116, 2213–2222] derived from otoacoustic emission data. Human cochlear traveling wave delay estimates were obta...

  15. A Click for the Good Life?

    DEFF Research Database (Denmark)

    Seifert, Claudia; Ohme, Jakob; Helm, Kerstin;

    This study investigates the influence of so called slacktivism on life satisfaction among users of the Social Network Site Facebook. Our work focuses on the moderating role that user motivation plays in utilizing this new and easy way of civic engagement online, especially on showing support for...... environmental, nature and animal protection, e.g. by signing an online-petition on Facebook. For this purpose a new scale to assess slacktivism was developed and tested with an online-survey among Facebook users (N= 1345). It revealed a high level of slacktivistic activities among SNS users, regardless of...... whether they already volunteered offline or not. Using regression modeling, it could be shown that slacktivism determines life satisfaction in a negative way, which is especially true for Facebook users who perform slacktivistic activities with a high intrinsic motivation. Furthermore, preceding criticism...

  16. 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.

  17. 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

    OpenAIRE

    Abdelkrim Thameur; Benamrane Karima; Bezza Badreddine

    2015-01-01

    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...

  18. An Efficient Single Impedance Network Three Level Z-Source Neutral Point Clamped Inverter

    Directory of Open Access Journals (Sweden)

    C.L.Kuppuswamy

    2012-07-01

    Full Text Available A multilevel inverter can eliminate the need for the step-up transformer and reduce the harmonics produced by the inverter. Although the multilevel inverter structure was initially introduced as a means of reducing the output waveform harmonic content, it was found that the dc bus voltage could be increased beyond the voltage rating of an individual power device by the use of a voltage clamping network consisting of diodes. By using voltage clamping techniques, the system KV rating can be extended beyond limits of an individual device. This paper presents Impedance (Z Source Neutral Point Clamped (NPC three level inverter with reduced number of impedance source networks and clamping diodes for non-linear loads. Earlier for a three level NPC inverter two separate impedance networks were used. But to reduce the circuit complexity without compromising with output requirement; only one impedance network is used and to substantiate this, the simulation of proposed circuit is carried out using MATLAB/Simulink for a 48 V input supply. A prototype is developed for an input voltage of 26V and the experimental results for the same are presented in this paper.

  19. Polycyclic aromatic hydrocarbons in urban air : concentration levels and patterns and source analysis in Nairobi, Kenya

    Energy Technology Data Exchange (ETDEWEB)

    Muthini, M.; Yoshimichi, H.; Yutaka, K.; Shigeki, M. [Yokohama National Univ., Yokohama (Japan). Graduate School of Environment and Information Sciences

    2005-07-01

    Polycyclic aromatic hydrocarbons (PAHs) present in the environment are often the result of incomplete combustion processes. This paper reported concentration levels and patterns of high molecular weight PAHs in Nairobi, Kenya. Daily air samples for 30 different PAHs were collected at residential, industrial and business sites within the city. Samples were then extracted using deuterated PAH with an automated Soxhlet device. Gas chromatography and mass spectrometry (GC-MS) with a capillary column was used to analyze the extracts using a selected ion monitoring (SIM) mode. Statistical analyses were then performed. PAH concentration levels were reported for average, median, standard deviation, range, and Pearson's correlation coefficients. Data were then analyzed for sources using a principal component analysis (PCA) technique and isomer ratio analysis. Nonparametric testing was then conducted to detect inherent differences in PAH concentration data obtained from the different sites. Results showed that pyrene was the most abundant PAH. Carcinogenic PAHs were higher in high-traffic areas. The correlation coefficient between coronene and benzo(ghi)pyrene was high. The PAH isomer ratio analysis demonstrated that PAHs in Nairobi are the product of traffic emissions and oil combustion. Results also showed that PAH profiles were not well separated. It was concluded that source distinction methods must be improved in order to better evaluate PAH emissions in the city. 9 refs., 2 tabs., 1 fig.

  20. Localized high indoor Rn levels in Israel - sources and remedial actions

    International Nuclear Information System (INIS)

    A few dwellings, having extremely high indoor Rn levels (exceeding 3000 Bq/m 3), were detected in recent years in Israel.The cases are presented and discussed.In all cases analysis was conducted in order to reveal the sources of the elevated levels, and consequently, remedial steps were taken. In all cases, the reason for the high indoor Rn concentration was found to be a combination of an elevated Ra-226 concentration in the soil under the house, and an extremely efficient entry route of the soil gas into the dwellings. It is the latter property that was found to be responsible for the high indoor Rn levels, since many houses are built on the same ground, and only in a very few of them the phenomenon was detected. Remedial action consisted mainly of blocking the entry route of the Rn into the hose. The remedial steps were effective, and reduction of Rn levels by factors exceeding 100 were obtained in some cases (from ∼ 20000 Bq/m3 to -150 Bq/m3). Combinations of entry blocking and increased ventilation produced even higher reduction factors.Ventilation alone resulted in a reduction factor of 3-4 only. (authors)

  1. Impacts of natural emission sources on particle pollution levels in Europe

    Science.gov (United States)

    Liora, Natalia; Poupkou, Anastasia; Giannaros, Theodore M.; Kakosimos, Konstantinos E.; Stein, Olaf; Melas, Dimitrios

    2016-07-01

    The main objective of this work is the study of the impact of windblown dust, sea-salt aerosol and biogenic emissions on particle pollution levels in Europe. The Natural Emissions MOdel (NEMO) and the modelling system consisted of the Weather Research and Forecasting model (WRF) and the Comprehensive Air Quality model with extensions (CAMx) were applied in a 30 km horizontal resolution grid, which covered Europe and the adjacent areas for the year 2009. Air quality simulations were performed for different emission scenarios in order to study the contribution of each natural emission source individually and together to air quality levels in Europe. The simulations reveal that the exclusion of windblown dust emissions decreases the mean seasonal PM10 levels by more than 3.3 μg/m3 (∼20%) in the Eastern Mediterranean during winter while an impact of 3 μg/m3 was also found during summer. The results suggest that sea-salt aerosol has a significant effect on PM levels and composition. Eliminating sea-salt emissions reduces PM10 seasonal concentrations by around 10 μg/m3 in Mediterranean Sea during summer while a decrease of up to 6 μg/m3 is found in Atlantic Ocean during autumn. Sea-salt particles also interact with the anthropogenic component and therefore their absence in the atmosphere decreases significantly the nitrates in aerosols where shipping activities are present. The exclusion of biogenic emissions in the model runs leads to a significant reduction of secondary organic aerosols of more than 90% while an increase in PM2.5 levels in central Europe and Eastern Mediterranean is found due to their interaction with anthropogenic component.

  2. Whistle source levels of free-ranging beluga whales in Saguenay-St. Lawrence marine park.

    Science.gov (United States)

    Le Bot, Olivier; Simard, Yvan; Roy, Nathalie; Mars, Jérôme I; Gervaise, Cédric

    2016-07-01

    Wild beluga whistle source levels (SLs) are estimated from 52 three-dimensional (3D) localized calls using a 4-hydrophone array. The probability distribution functions of the root-mean-square (rms) SL in the time domain, and the peak, the strongest 3-dB, and 10-dB SLs from the spectrogram, were non-Gaussian. The average rms SL was 143.8 ± 6.7 dB re 1 μPa at 1 m. SL spectral metrics were, respectively, 145.8 ± 8 dB, 143.2 ± 7.1 dB, and 138.5 ± 6.9 dB re 1 μPa(2)·Hz(-1) at 1 m. PMID:27475219

  3. Low-level radioactive waste source term model development and testing: Topical report

    International Nuclear Information System (INIS)

    The Low-Level Waste Source Term Evaluation Project has the objective to develop a system model capable of predicting radionuclide release rates from a shallow land burial facility. The previous topical report for this project discussed the framework and methodology for developing a system model and divided the problem into four compartments: water flow, container degradation, waste form leaching, and radionuclide transport. Each of these compartments is described by submodels which will be coupled into the system model. From February 1987 to March 1988, computer models have been selected to predict water flow (FEMWATER) and radionuclide transport (FEMWASTE) and separate models have been developed to predict pitting corrosion of steel containers and leaching from porous waste forms contained in corrodible containers. This report discusses each of the models in detail and presents results obtained from applying the models to shallow land burial trenches over a range of expected conditions. 68 refs., 34 figs., 14 tabs

  4. Level, potential sources of polycyclic aromatic hydrocarbons (PAHs) in particulate matter (PM10) in Naples

    Science.gov (United States)

    Di Vaio, Paola; Cocozziello, Beatrice; Corvino, Angela; Fiorino, Ferdinando; Frecentese, Francesco; Magli, Elisa; Onorati, Giuseppe; Saccone, Irene; Santagada, Vincenzo; Settimo, Gaetano; Severino, Beatrice; Perissutti, Elisa

    2016-03-01

    In Naples, particulate matter PM10 associated with polycyclic aromatic hydrocarbons (PAHs) in ambient air were determined in urban background (NA01) and urban traffic (NA02) sites. The principal objective of the study was to determine the concentration and distribution of PAHs in PM10 for identification of their possible sources (through diagnostic ratio - DR and principal component analysis - PCA) and an estimation of the human health risk (from exposure to airborne TEQ). Airborne PM10 samples were collected on quartz filters using a Low Volume Sampler (LVS) for 24 h with seasonal samples (autumn, winter, spring and summer) of about 15 days each between October 2012 and July 2013. The PM10 mass was gravimetrically determined. The PM10 levels, in all seasons, were significantly higher (P Perylene), had a large contribution (∼50-55%) of total PAHs concentration in PM10 in two sites and in each of the campaigns. Diagnostic ratio analysis and PCA suggested a substantial contributions from traffic emission with minimal influence from coal combustion and natural gas emissions. In particular diesel vehicular emissions were the major source of PAHs at the studied sites. The use of Toxicity Equivalence Quantity (TEQ) concentration provide a better estimation of carcinogenicity activities; health risk to adults and children associated with PAHs inhalation was assessed by taking into account the lifetime average daily dose and corresponding incremental lifetime cancer risk (ILCR). The ILCR was within the acceptable range (10-6-10-4), indicating a low health risk to residents in these areas.

  5. Levels and source apportionment of volatile organic compounds in southwestern area of Mexico City

    Energy Technology Data Exchange (ETDEWEB)

    Rodolfo Sosa, E. [Centro de Ciencias de la Atmosfera, Universidad Nacional Autonoma de Mexico, Circuito Exterior, Ciudad Universitaria, C.P. 04510, D.F. (Mexico); Humberto Bravo, A. [Centro de Ciencias de la Atmosfera, Universidad Nacional Autonoma de Mexico, Circuito Exterior, Ciudad Universitaria, C.P. 04510, D.F. (Mexico)], E-mail: hbravo@servidor.unam.mx; Violeta Mugica, A. [Universidad Autonoma Metropolitana, Azcapotzalco, D.F. (Mexico); Pablo Sanchez, A. [Centro de Ciencias de la Atmosfera, Universidad Nacional Autonoma de Mexico, Circuito Exterior, Ciudad Universitaria, C.P. 04510, D.F. (Mexico); Emma Bueno, L. [Centro Nacional de Investigacion y Capacitacion Ambiental, Instituto Nacional de Ecologia (Mexico); Krupa, Sagar [Department of Plant Pathology, University of Minnesota, St. Paul, MN 55108 (United States)

    2009-03-15

    Thirteen volatile organic compounds (VOCs) were quantified at three sites in southwestern Mexico City from July 2000 to February 2001. High concentrations of different VOCs were found at a Gasoline refueling station (GS), a Condominium area (CA), and at University Center for Atmospheric Sciences (CAS). The most abundant VOCs at CA and CAS were propane, n-butane, toluene, acetylene and pentane. In comparison, at GS the most abundant were toluene, pentane, propane, n-butane, and acetylene. Benzene, a known carcinogenic compound had average levels of 28, 35 and 250 ppbC at CAS, CA, and GS respectively. The main contributing sources of the measured VOCs at CA and CAS were the handling and management of LP (Liquid Propane) gas, vehicle exhaust, asphalt works, and use of solvents. At GS almost all of the VOCs came from vehicle exhaust and fuel evaporation, although components of LP gas were also present. Based on the overall results possible abatement strategies are discussed. - Volatile organic compounds were quantified in order to perform their source apportionment in southwestern area of Mexico City.

  6. Sea Level and Paleoenvironment Control on Late Ordovician Source Rocks, Hudson Bay Basin, Canada

    Science.gov (United States)

    Zhang, S.; Hefter, J.

    2009-05-01

    Hudson Bay Basin is one of the largest Paleozoic sedimentary basins in North America, with Southampton Island on its north margin. The lower part of the basin succession comprises approximately 180 to 300 m of Upper Ordovician strata including Bad Cache Rapids and Churchill River groups and Red Head Rapids Formation. These units mainly comprise carbonate rocks consisting of alternating fossiliferous limestone, evaporitic and reefal dolostone, and minor shale. Shale units containing extremely high TOC, and interpreted to have potential as petroleum source rocks, were found at three levels in the lower Red Head Rapids Formation on Southampton Island, and were also recognized in exploration wells from the Hudson Bay offshore area. A study of conodonts from 390 conodont-bearing samples from continuous cores and well cuttings from six exploration wells in the Hudson Bay Lowlands and offshore area (Comeault Province No. 1, Kaskattama Province No. 1, Pen Island No. 1, Walrus A-71, Polar Bear C-11 and Narwhal South O-58), and about 250 conodont-bearing samples collected from outcrops on Southampton Island allows recognition of three conodont zones in the Upper Ordovician sequence, namely (in ascendant sequence) Belodina confluens, Amorphognathus ordovicicus, and Rhipidognathus symmetricus zones. The three conodont zones suggest a cycle of sea level changes of rising, reaching the highest level, and then falling during the Late Ordovician. Three intervals of petroleum potential source rock are within the Rhipidognathus symmetricus Zone in Red Head Rapids Formation, and formed in a restricted anoxic and hypersaline condition during a period of sea level falling. This is supported by the following data: 1) The conodont Rhipidognathus symmetricus represents the shallowest Late Ordovician conodont biofacies and very shallow subtidal to intertidal and hypersaline condition. This species has the greatest richness within the three oil shale intervals to compare other parts of Red

  7. Levels of bioactive lipids in cooking oils: olive oil is the richest source of oleoyl serine

    Science.gov (United States)

    Leishman, Emma

    2016-01-01

    Background Rates of osteoporosis are significantly lower in regions of the world where olive oil consumption is a dietary cornerstone. Olive oil may represent a source of oleoyl serine (OS), which showed efficacy in animal models of osteoporosis. Here, we tested the hypothesis that OS as well as structurally analogous N-acyl amide and 2-acyl glycerol lipids are present in the following cooking oils: olive, walnut, canola, high heat canola, peanut, safflower, sesame, toasted sesame, grape seed, and smart balance omega. Methods Methanolic lipid extracts from each of the cooking oils were partially purified on C-18 solid-phase extraction columns. Extracts were analyzed with high-performance liquid chromatography-tandem mass spectrometry, and 33 lipids were measured in each sample, including OS and bioactive analogs. Results Of the oils screened here, walnut oil had the highest number of lipids detected (22/33). Olive oil had the second highest number of lipids detected (20/33), whereas grape-seed and high-heat canola oil were tied for lowest number of detected lipids (6/33). OS was detected in 8 of the 10 oils tested and the levels were highest in olive oil, suggesting that there is something about the olive plant that enriches this lipid. Conclusions Cooking oils contain varying levels of bioactive lipids from the N-acyl amide and 2-acyl glycerol families. Olive oil is a dietary source of OS, which may contribute to lowered prevalence of osteoporosis in countries with high consumption of this oil. PMID:26565552

  8. Sources of atmospheric aerosols controlling PM10 levels in Heraklion, Crete during winter time

    Science.gov (United States)

    Kalivitis, Nikolaos; Kouvarakis, Giorgos; Stavroulas, Iasonas; Kandilogiannaki, Maria; Vavadaki, Katerina; Mihalopoulos, Nikolaos

    2016-04-01

    High concentrations of Particulate Matter (PM) in the atmosphere have negative impact to human health. Thresholds for ambient concentrations that are defined by the directive 2008/50/EC are frequently exceeded even at background conditions in the Mediterranean region as shown in earlier studies. The sources of atmospheric particles in the urban environment of a medium size city of eastern Mediterranean are studied in the present work in order to better understand the causes and characteristics of exceedances of the daily mean PM10limit value of 50 μg m‑3. Measurements were performed at the atmospheric quality measurement station of the Region of Crete, at the Heraklion city center on Crete island, during the winter/spring period of 2014-2015 and 2015-2016. Special emphasis was given to the study of the contribution of Black Carbon (BC) to the levels of PM10. Continuous measurements were performed using a beta-attenuation PM10monitor and a 7-wavelength Aethalometer with a time resolution of 30 and 5 minutes respectively. For direct comparison to background regional conditions, concurrent routine measurements at the atmospheric research station of University of Crete at Finokalia were used as background reference. Analysis of exceedances in the daily PM10 mass concentration showed that the total of the exceedances was related to long range transport of Saharan dust rather than local sources. However, compared to the Finokalia station it was found that there were 20% more exceedances in Heraklion, the addition of transported dust on the local pollution was the reason for the additional exceedance days. Excluding dust events, it was found that the PM10variability was dependent on the BC abundance, traffic during rush hours in the morning and biomass burning for domestic heating in the evening contributed significantly to PM10levels in Heraklion.

  9. Sources and levels of ambient ocean sound near the Antarctic Peninsula.

    Science.gov (United States)

    Dziak, Robert P; Bohnenstiehl, DelWayne R; Stafford, Kathleen M; Matsumoto, Haruyoshi; Park, Minkyu; Lee, Won Sang; Fowler, Matt J; Lau, Tai-Kwan; Haxel, Joseph H; Mellinger, David K

    2015-01-01

    Arrays of hydrophones were deployed within the Bransfield Strait and Scotia Sea (Antarctic Peninsula region) from 2005 to 2009 to record ambient ocean sound at frequencies of up to 125 and 500 Hz. Icequakes, which are broadband, short duration signals derived from fracturing of large free-floating icebergs, are a prominent feature of the ocean soundscape. Icequake activity peaks during austral summer and is minimum during winter, likely following freeze-thaw cycles. Iceberg grounding and rapid disintegration also releases significant acoustic energy, equivalent to large-scale geophysical events. Overall ambient sound levels can be as much as ~10-20 dB higher in the open, deep ocean of the Scotia Sea compared to the relatively shallow Bransfield Strait. Noise levels become lowest during the austral winter, as sea-ice cover suppresses wind and wave noise. Ambient noise levels are highest during austral spring and summer, as surface noise, ice cracking and biological activity intensifies. Vocalizations of blue (Balaenoptera musculus) and fin (B. physalus) whales also dominate the long-term spectra records in the 15-28 and 89 Hz bands. Blue whale call energy is a maximum during austral summer-fall in the Drake Passage and Bransfield Strait when ambient noise levels are a maximum and sea-ice cover is a minimum. Fin whale vocalizations were also most common during austral summer-early fall months in both the Bransfield Strait and Scotia Sea. The hydrophone data overall do not show sustained anthropogenic sources (ships and airguns), likely due to low coastal traffic and the typically rough weather and sea conditions of the Southern Ocean. PMID:25875205

  10. Sources and levels of ambient ocean sound near the Antarctic Peninsula.

    Directory of Open Access Journals (Sweden)

    Robert P Dziak

    Full Text Available Arrays of hydrophones were deployed within the Bransfield Strait and Scotia Sea (Antarctic Peninsula region from 2005 to 2009 to record ambient ocean sound at frequencies of up to 125 and 500 Hz. Icequakes, which are broadband, short duration signals derived from fracturing of large free-floating icebergs, are a prominent feature of the ocean soundscape. Icequake activity peaks during austral summer and is minimum during winter, likely following freeze-thaw cycles. Iceberg grounding and rapid disintegration also releases significant acoustic energy, equivalent to large-scale geophysical events. Overall ambient sound levels can be as much as ~10-20 dB higher in the open, deep ocean of the Scotia Sea compared to the relatively shallow Bransfield Strait. Noise levels become lowest during the austral winter, as sea-ice cover suppresses wind and wave noise. Ambient noise levels are highest during austral spring and summer, as surface noise, ice cracking and biological activity intensifies. Vocalizations of blue (Balaenoptera musculus and fin (B. physalus whales also dominate the long-term spectra records in the 15-28 and 89 Hz bands. Blue whale call energy is a maximum during austral summer-fall in the Drake Passage and Bransfield Strait when ambient noise levels are a maximum and sea-ice cover is a minimum. Fin whale vocalizations were also most common during austral summer-early fall months in both the Bransfield Strait and Scotia Sea. The hydrophone data overall do not show sustained anthropogenic sources (ships and airguns, likely due to low coastal traffic and the typically rough weather and sea conditions of the Southern Ocean.

  11. Meta-analysis on Methane Mitigating Properties of Saponin-rich Sources in the Rumen: Influence of Addition Levels and Plant Sources

    OpenAIRE

    Jayanegara, Anuraga; Wina, Elizabeth; TAKAHASHI, Junichi

    2014-01-01

    Saponins have been considered as promising natural substances for mitigating methane emissions from ruminants. However, studies reported that addition of saponin-rich sources often arrived at contrasting results, i.e. either it decreased methane or it did not. The aim of the present study was to assess ruminal methane emissions through a meta-analytical approach of integrating related studies from published papers which described various levels of different saponin-rich sources being added to...

  12. RSD-WSN: remote source-level debugger for rapid application development in wireless sensor networks

    Science.gov (United States)

    Mozumdar, Mohammad M.; Bian, Weiyuan; Perez, Jose; Lavagno, Luciano

    2013-05-01

    Debugging Wireless Sensor Network (WSN) applications deployed on actual sensor nodes is difficult, since debuggers normally require a wired (e.g. USB) interface. In this paper we propose a mechanism for WSN application debugging that is based on remote access, through the wireless interface, and that uses the native environment in which the application was developed (i.e. it acts as a source-level debugger). The approach, called RSD-WSN, is based on creating continuous behavioral snapshots of a remotely located sensor node by binding it with a virtual node. Hence by using RSD-WSN, users can debug a WSN application node that is running remotely. This framework allows a programmer to develop an application using high level abstractions (finite state machine) and then automatically generate code for target platforms. The complied generated code could be then directly loaded on sensor nodes and the framework provides interfaces by which an application developer can bind execution sequences of a remote sensor node with a virtual simulated node, so that the developer can monitor node behavior and refine the application in case of unexpected behaviors.

  13. New insights on the Messina 1908 seismic source from post-seismic sea level change

    Science.gov (United States)

    Cannelli, V.; Melini, D.; Piersanti, A.

    2013-08-01

    The identification of a source model for the catastrophic 1908 December 28 Messina earthquake (Mw = 7.2) has been the subject of many papers in the last decades. Several authors proposed different models on the basis of seismological, macroseismic and geodetic data sets; among these models, remarkable differences exist with regard to almost all parameters. We selected a subset of six models among those most cited in literature and used them to model the post-seismic sea level variation recorded at the tide gauge station of Messina (until 1923), to attempt an independent discrimination among them. For each model, we assumed a simple rheological structure and carried out a direct-search inversion of upper crust thickness and lower crust viscosity to fit the post-seismic sea level signal. This approach enabled us to identify a class of fault geometries which is consistent with the post-seismic signal at the Messina tide gauge and with the known structural and rheological features of the Messina strait.

  14. Operational Analysis and Modulation Control of Three-Level Z-Source Inverters With Enhanced Output Waveform Quality

    DEFF Research Database (Denmark)

    Loh, Poh Chiang; Blaabjerg, Frede; Lim, Sok Wei;

    2007-01-01

    Three-level Z-source inverters are recent single-stage topological solutions proposed for buck-boost energy conversion with all favorable advantages of three-level switching retained. Despite their proven buck-boost capability, existing three-level Z-source inverters are either too costly with...... numerous passive LC elements needed or poor in spectral quality if the "reduced element count" (REC) variant is used. Instead of being constrained by the tradeoff, this paper proposes an alternative three-level Z-source topological and control combination that can produce optimal output waveform quality......, while using lesser passive LC elements. Through detailed operational analysis, new operating modes of the REC Z-source inverters are identified, which when inserted appropriately to the inverter state sequence, will always produce the desired voltage transfer gain with minimized commutation count and...

  15. Southern Dobrogea coastal potable water sources and Upper Quaternary Black Sea level changes

    Science.gov (United States)

    Caraivan, Glicherie; Stefanescu, Diana

    2013-04-01

    Southern Dobrogea is a typical geologic platform unit, placed in the south-eastern part of Romania, with a Pre-Cambrian crystalline basement and a Paleozoic - Quaternary sedimentary cover. It is bordered to the north by the Capidava - Ovidiu fault and by the Black Sea to the east. A regional WNW - ESE and NNE - SSW fault system divides the Southern Dobrogea structure in several tectonic blocks. Four drinking water sources have been identified: surface water, phreatic water, medium depth Sarmatian aquifer, and deep Upper Jurassic - Lower Cretaceous aquifer. Surface water sources are represented by several springs emerged from the base of the loess cliff, and a few small rivers, barred by coastal beaches. The phreatic aquifer develops at the base of the loess deposits, on the impervious red clay, overlapping the Sarmatian limestones. The medium depth aquifer is located in the altered and karstified Sarmatian limestones, and discharges into the Black Sea. The Sarmatian aquifer is unconfined where covered by silty loess deposits, and locally confined, where capped by clayey loess deposits. The aquifer is supplied from the Pre-Balkan Plateau. The Deep Upper Jurassic - Lower Cretaceous aquifer, located in the limestone and dolomite deposits, is generally confined and affected by the regional WNW - ESE and NNE - SSW fault system. In the south-eastern Dobrogea, the deep aquifer complex is separated from the Sarmatian aquifer by a Senonian aquitard (chalk and marls). The natural boundary of the Upper Jurassic - Lower Cretaceous aquifer is the Capidava - Ovidiu Fault. The piezometric heads show that the Upper Jurassic - Lower Cretaceous aquifer is supplied from the Bulgarian territory, where the Upper Jurassic deposits crop out. The aquifer discharges into the Black Sea to the east and into Lake Siutghiol to the northeast. The cyclic Upper Quaternary climate changes induced drastic remodeling of the Black Sea level and the corresponding shorelines. During the Last Glacial

  16. Microwave assisted click chemistry on a conductive polymer film

    DEFF Research Database (Denmark)

    Daugaard, Anders Egede; Hansen, Thomas S.; Larsen, Niels Bent;

    2011-01-01

    Microwave (MW) irradiation has been used to accelerate the functionalization of an azide functional poly(3,4-ethylenedioxythiophene) film by click chemistry. The absorption of MW energy by the conductive polymer has been exploited for localized activation of the reaction on the polymer surface. B...... method has been applied for anchoring of the chelating agent nitrilotriacetic acid (NTA) on the conductive polymer. The chelating linkage ability of NTA on the surface was investigated through a sandwich ELISA study confirming the selective bonding of a histidine tagged protein....

  17. Superstructures of fluorescent cyclodextrin via click-reaction

    Directory of Open Access Journals (Sweden)

    Arkadius Maciollek

    2013-04-01

    Full Text Available Mono-(6-azido-6-deoxy-β-cyclodextrin (CD was covalently attached to an alkyne-modified 5-methyl-2-(pyridin-2-ylthiazol-4-ol yielding a fluorophore containing CD in a click-type reaction. Intermolecular complexes were formed by poly(host–guest-interactions. The supramolecular structures were characterized by 1H NMR-ROESY spectroscopy, dynamic light scattering, UV–vis spectroscopy, fluorescence spectroscopy, and asymmetric flow field-flow fractionation. By adding potassium adamantane-1-carboxylate, the thiazol dye is displaced from the CD-cavity and the elongated noncovalent polymeric structures collapse.

  18. Functionalization of PEDOT by Click Chemistry and ATRP

    DEFF Research Database (Denmark)

    Hoffmann, Christian; Daugaard, Anders Egede

    Poly(3,4‐ethylenedioxythiophene) (PEDOT) is a conductive polymer which has received increasing attention and many developments have been investigated. PEDOT has been applied in many different areas such as biosensors or polymer solar cells. This work presents a modification of PEDOT films through...... Click Chemistry with alkynes followed by activator regenerated by electron transfer (ARGET) atom transfer radical polymerization (ATRP) to develop PEDOT films with anti‐fouling properties through application of a model system based on a crosslinked surface of polystyrene PS‐N3....

  19. Universal dark quencher based on "clicked" spectrally distinct azo dyes.

    Science.gov (United States)

    Chevalier, Arnaud; Hardouin, Julie; Renard, Pierre-Yves; Romieu, Anthony

    2013-12-01

    The first synthesis of an heterotrifunctional molecular scaffold derived from the popular DABCYL azo dye quencher has been achieved. The sequential derviatization of this trivalent azobenzene derivative with two other nonfluorescent azo dyes (Black Hole Quencher BHQ-1 and BHQ-3) and through effective reactions from the "bioconjugation chemistry" repertoire has led to an universal dark quencher (UDQ). This "clicked" poly azo dye is able to turn off an array of fluorophores covering the UV/NIR (300-750 nm) spectral range. PMID:24215300

  20. Growing Applications of “Click Chemistry” for Bioconjugation in Contemporary Biomedical Research

    OpenAIRE

    Nwe, Kido; Martin W. Brechbiel

    2009-01-01

    This update summarizes the growing application of “click” chemistry in diverse areas such as bioconjugation, drug discovery, materials science, and radiochemistry. This update also discusses click chemistry reactions that proceed rapidly with high selectivity, specificity, and yield. Two important characteristics make click chemistry so attractive for assembling compounds, reagents, and biomolecules for preclinical and clinical applications. First, click reactions are bio-orthogonal; neither ...

  1. Auctions for online ad space among advertisers sensitive to both views and clicks

    OpenAIRE

    MAILLÉ, Patrick; Tuffin, Bruno

    2015-01-01

    Advertisement in dedicated webpage spaces or in search engines sponsored slots is usually sold using auctions, with a payment rule that is either per view or per click. But advertisers can be both sensitive to being viewed (brand awareness effect) and being clicked (conversion into sales). In this paper, we generalize the auction mechanism by including both pricing components: the displayed advertisers are charged when their ad is displayed, and pay an additional price if the ad is clicked. A...

  2. Middle ear myoclonus: a new technique for suppression of spontaneous clicking tinnitus.

    Science.gov (United States)

    Chan, Chung; Palaniappan, Rudrapathy

    2010-01-01

    Middle ear myoclonus is one of the causes of clicking tinnitus and can be psychologically distressing. Current management of intractable clicking includes medication or tenotomy. Two cases with spontaneous intrusive irregular clicking are presented where relief and a sense of control were obtained using non-invasive self - administered zygomatic pressure. This technique may be useful in selected patients before resorting to medication or tenotomy. PMID:21609914

  3. Level, potential sources of polycyclic aromatic hydrocarbons (PAHs) in particulate matter (PM10) in Naples

    Science.gov (United States)

    Di Vaio, Paola; Cocozziello, Beatrice; Corvino, Angela; Fiorino, Ferdinando; Frecentese, Francesco; Magli, Elisa; Onorati, Giuseppe; Saccone, Irene; Santagada, Vincenzo; Settimo, Gaetano; Severino, Beatrice; Perissutti, Elisa

    2016-03-01

    In Naples, particulate matter PM10 associated with polycyclic aromatic hydrocarbons (PAHs) in ambient air were determined in urban background (NA01) and urban traffic (NA02) sites. The principal objective of the study was to determine the concentration and distribution of PAHs in PM10 for identification of their possible sources (through diagnostic ratio - DR and principal component analysis - PCA) and an estimation of the human health risk (from exposure to airborne TEQ). Airborne PM10 samples were collected on quartz filters using a Low Volume Sampler (LVS) for 24 h with seasonal samples (autumn, winter, spring and summer) of about 15 days each between October 2012 and July 2013. The PM10 mass was gravimetrically determined. The PM10 levels, in all seasons, were significantly higher (P agents, (i.e Benzo[a]Pyrene, Indeno[1,2,3-cd]Pyrene, Benzo[b]Fluoranthene, Benzo[k]Fluoranthene and Benzo[g,h,i]Perylene), had a large contribution (∼50-55%) of total PAHs concentration in PM10 in two sites and in each of the campaigns. Diagnostic ratio analysis and PCA suggested a substantial contributions from traffic emission with minimal influence from coal combustion and natural gas emissions. In particular diesel vehicular emissions were the major source of PAHs at the studied sites. The use of Toxicity Equivalence Quantity (TEQ) concentration provide a better estimation of carcinogenicity activities; health risk to adults and children associated with PAHs inhalation was assessed by taking into account the lifetime average daily dose and corresponding incremental lifetime cancer risk (ILCR). The ILCR was within the acceptable range (10-6-10-4), indicating a low health risk to residents in these areas.

  4. Intake levels and major food sources of energy and nutrients in the Taiwanese elderly.

    Science.gov (United States)

    Wu, Shin-Jiuan; Chang, Ya-Hui; Wei, Ien-Lan; Kao, Mei-Ding; Lin, Yi-Chin; Pan, Wen-Harn

    2005-01-01

    The purpose of this article is to examine dietary intake levels and major food sources of energy and nutrients for the Taiwanese elderly in order to relate nutrient intakes to food choices and to provide suggestions for dietary improvement. The data were derived from the 24-hour recalls from 1,911 subjects (955 males and 956 females) aged 65 and above, who participated in the Elderly NAHSIT carried out from 1999 to 2000. The differences in food consumption patterns between the elderly and younger adults (aged 19 to 64) were also evaluated by comparison with data obtained from NAHSIT 1993-1996. The results revealed that cereals/roots, meat, other protein-rich foods and fats/oils contributed most to daily energy intake. The energy contributions from fats/oils, poultry, meat, other protein-rich foods, refreshments/snacks, alcoholic beverages, and miscellaneous food groups were lower in elderly diets compared with those of younger adults. Meat and cereals/roots were the major food sources of protein. The main carbohydrate-contributing food group was cereals/roots, while primary lipid sources were meat and fats/oils for the elderly. The food groups with a high contribution to vitamin intake were the following: vegetables for vitamin A; meat and cereals/roots for vitamin B1; dairy products, vegetables, cereals/roots and meat for vitamin B2; cereals/roots, seafood and meat for niacin; meat, vegetables and cereals/roots for vitamin B6; plant oils for vitamin E; and vegetables and fruit for vitamin C. The highest ranked food sources for minerals are listed as follows: dairy products, vegetables and seafood for calcium; dairy products and cereals/roots for phosphorous; vegetables and meat for iron; and vegetables, cereals/ roots, other protein-rich foods and seafood for magnesium. The elderly were found to consume more salt, dairy products and vegetables, but less poultry and meat than their younger counterparts. In summary, differences in consumption patterns between the

  5. A new three-level current-source PWM inverter and its application for grid connected power conditioner

    International Nuclear Information System (INIS)

    This paper presents a novel topology of a three-level current-source PWM inverter totally driven by using single gate-drive power supply used for a grid connected inverter. The great feature of the proposed inverter circuit is that all of the power switches are connected on common-source or common-emitter configuration. Using this common-source current-source inverter (CS-CSI) the number of gate-drive power supply can dramatically be reduced into only a single power source without using bootstrap technique or many isolated power supplies. Operation of the proposed new inverter was tested by using computer simulation and experimentally. The simulation and experimental results proved that the inverter works properly generate a three-level output current waveform and inject a sinusoidal current into power grid with unity power factor operation. During grid connected operation, almost all harmonic orders are suppressed by using an additional harmonic suppression technique.

  6. Polychlorinated Biphenyl Sources, Emissions, and Environmental Levels in school Buildings (PCB Workshop presentation)

    Science.gov (United States)

    Measure PCB emission rates from primary sources in laboratory chambersMeasure transport and sorption by materials and dust in laboratory chambersCharacterize PCBs in school building materialsEstimate PCB emission rates from sources in schoolsExamine congener patterns in sources a...

  7. Redox-Responsive Micelles with Cores Crosslinked via Click Chemistry.

    Science.gov (United States)

    Zhang, Xiaojin; Dong, Hui; Fu, Shuangli; Zhong, Zhenlin; Zhuo, Renxi

    2016-06-01

    Redox-responsive micelles with cores crosslinked via click chemistry are developed to improve the stability of polymer micelles. Amphiphilic block copolymer mPEG-b-P(DTC-ADTC) with pendant azido groups on the hydrophobic chains is synthesized by the ring-opening polymerization of 2,2-bis(azidomethyl)trimethylene carbonate (ADTC) and 2,2-dimethyltrimethylene carbonate (DTC) with monomethoxy poly(ethylene glycol) (mPEG) as an initiator. mPEG-b-P(DTC-ADTC) self-assemble to form the micelles in aqueous solution and the cores of the micelles are crosslinked via click chemistry to afford redox-responsive core-crosslinked micelles. Core-crosslinking enhances the stability of the micelles in aqueous solution and improve the drug-loading property. The redox-responsive core-crosslinked micelles can be reduced by the addition of reducing agents such as dithiothreitol (DTT), and thus release the loaded drug quickly in the presence of DTT. PMID:27150437

  8. Binding-regulated click ligation for selective detection of proteins.

    Science.gov (United States)

    Cao, Ya; Han, Peng; Wang, Zhuxin; Chen, Weiwei; Shu, Yongqian; Xiang, Yang

    2016-04-15

    Herein, a binding-regulated click ligation (BRCL) strategy for endowing selective detection of proteins is developed with the incorporation of small-molecule ligand and clickable DNA probes. The fundamental principle underlying the strategy is the regulating capability of specific protein-ligand binding against the ligation between clickable DNA probes, which could efficiently combine the detection of particular protein with enormous DNA-based sensing technologies. In this work, the feasibly of the BRCL strategy is first verified through agarose gel electrophoresis and electrochemical impedance spectroscopy measurements, and then confirmed by transferring it to a nanomaterial-assisted fluorescence assay. Significantly, the BRCL strategy-based assay is able to respond to target protein with desirable selectivity, attributing to the specific recognition between small-molecule ligand and its target. Further experiments validate the general applicability of the sensing method by tailoring the ligand toward different proteins (i.e., avidin and folate receptor), and demonstrate its usability in complex biological samples. To our knowledge, this work pioneers the practice of click chemistry in probing specific small-molecule ligand-protein binding, and therefore may pave a new way for selective detection of proteins. PMID:26599478

  9. Grafting of Polycaprolactone on Oxidized Nanocelluloses by Click Chemistry

    Directory of Open Access Journals (Sweden)

    Claude Daneault

    2013-03-01

    Full Text Available The main objective of this work is the grafting of polycaprolactone diol (PCL on the surface of oxidized nanocelluloses (ONC in order to enhance the compatibility between the hydrophilic cellulose nanofibres and the hydrophobic polymer matrix. This grafting was successfully realized with a new strategy known as click chemistry. In this context, the oxidized nanocelluloses bearing alkyl groups (ONC-PR were prepared by reacting amino groups of propargylamine (PR with carboxyl groups of ONC. In parallel, PCL was converted into azido-polycaprolactone (PCL-N3 in two steps: (i tosylation of polycaprolactone (PCL-OTs and (ii conversion of PCL-OTs into PCL-N3 by nucleophilic displacement using sodium azide. Finally, ONC-PR was reacted with PCL-N3 in heterogeneous conditions through click chemistry in order to prepare polycaprolactone grafted oxidized nanocellulose (ONC-g-PCL, which could be suitable for improving the interfacial adhesion in the composite materials. The grafted samples were characterized by transmission electron microscopy and by Fourier transform infrared spectroscopy (FTIR, X-ray photoelectron spectroscopy (XPS and Carbon-13 nuclear magnetic resonance spectroscopy (13C-NMR spectroscopic techniques.

  10. Five-Level Current-Source Inverters With Buck–Boost and Inductive-Current Balancing Capabilities

    DEFF Research Database (Denmark)

    Gao, Feng; Loh, Poh Chiang; Blaabjerg, Frede; Vilathgamuwa, D. Mahinda

    2010-01-01

    This paper presents new five-level current-source inverters (CSIs) with voltage/current buck–boost capability, unlike existing five-level CSIs where only voltage–boost operation is supported. The proposed inverters attain self-inductive-currentbalancing per switching cycle at their dc front ends...... verified in simulation and experimentally using a scaled-down laboratory platform....

  11. Point source influence on observed extreme pollution levels in a monitoring network

    Science.gov (United States)

    Ensor, Katherine B.; Ray, Bonnie K.; Charlton, Sarah J.

    2014-08-01

    This paper presents a strategy to quantify the influence major point sources in a region have on extreme pollution values observed at each of the monitors in the network. We focus on the number of hours in a day the levels at a monitor exceed a specified health threshold. The number of daily exceedances are modeled using observation-driven negative binomial time series regression models, allowing for a zero-inflation component to characterize the probability of no exceedances in a particular day. The spatial nature of the problem is addressed through the use of a Gaussian plume model for atmospheric dispersion computed at locations of known emissions, creating covariates that impact exceedances. In order to isolate the influence of emitters at individual monitors, we fit separate regression models to the series of counts from each monitor. We apply a final model clustering step to group monitor series that exhibit similar behavior with respect to mean, variability, and common contributors to support policy decision making. The methodology is applied to eight benzene pollution series measured at air quality monitors around the Houston ship channel, a major industrial port.

  12. Operational Analysis and Modulation Control of Three-Level Z-Source Inverters With Enhanced Output Waveform Quality

    DEFF Research Database (Denmark)

    Chiang Loh, Poh; Gao, Feng; Blaabjerg, Frede;

    2009-01-01

    Three-level Z-source inverters are recent single-stage topological solutions proposed for buck-boost energy conversion with all favorable advantages of three-level switching retained. Despite their proven buck-boost capability, existing three-level Zsource inverters are either too costly with...... numerous passive LC elements needed or poor in spectral quality if the "reduced element count" (REC) variant is used. Instead of being constrained by the tradeoff, this paper proposes an alternative three-level Z-source topological and control combination that can produce optimal output waveform quality...... while using lesser passive LC elements. Through detailed operational analysis, new operating modes of the REC Z-source inverters are identified, which when inserted appropriately to the inverter state sequence will always produce the desired voltage transfer gain with minimized commutation count and...

  13. Greenhouse Gas Emissions from Ground Level Area Sources in Dairy and Cattle Feedyard Operations

    Directory of Open Access Journals (Sweden)

    Calvin B. Parnell

    2011-08-01

    Full Text Available A protocol that consisted of an isolation flux chamber and a portable gas chromatograph was used to directly quantify greenhouse gas (GHG emissions at a dairy and a feedyard operation in the Texas Panhandle. Field sampling campaigns were performed 5 consecutive days only during daylight hours from 9:00 am to 7:00 pm each day. The objective of this research was to quantify and compare GHG emission rates (ERs from ground level area sources (GLAS at dairy and cattle feedyard operations during the summer. A total of 74 air samples using flux chamber were collected from the barn (manure lane and bedding area, loafing pen, open lot, settling basin, lagoons, and compost pile within the dairy operation. For the cattle feedyard, a total of 87 air samples were collected from four corner pens of a large feedlot, runoff holding pond, and compost pile. Three primary GHGs (methane, carbon dioxide, and nitrous oxide were measured and quantified from both operations. The aggregate estimated ERs for CH4, CO2, and N2O were 836, 5573, 3.4 g hd−1 d−1 (collectively 27.5 kg carbon dioxide equivalent (CO2e hd−1 d−1, respectively, at the dairy operation. The aggregate ERs for CH4, CO2, and N2O were 3.8, 1399, 0.68 g hd−1 d−1 (1.7 kg CO2e hd−1 d−1, respectively, from the feedyard. The estimated USEPA GHG ERs were about 13.2 and 1.16 kg CO2e hd−1 d−1, respectively, for dairy and feedyard operations. Aggregate CH4, CO2 and N2O ERs at the dairy facility were about 219, 4 and 5 times higher, respectively, than those at the feedyard. At the dairy, average CH4 ERs estimated from the settling basin, primary and secondary lagoons were significantly higher than those from the other GLAS, contributing about 98% of the aggregate CH4 emission. The runoff holding pond and pen surface of the feedyard contributed about 99% of the aggregate CH4 emission. Average CO2 and N2O ERs estimated from the pen surface area were significantly higher than those estimated from

  14. Sources

    OpenAIRE

    2015-01-01

    Sources Fondation Pablo Iglesias. Alcala de Henares. Sections : Archives privées de Manuel ArijaArchives extérieuresArchives FNJS de EspañaPrensa Archives Générales de l’Administration. Alcala de Henares. Sections : Opposition au franquismeSig. 653 Sig TOP 82/68.103-68.602.Índice de las cartas colectivas, Relaciones, Cartas al Ministro de Información de Marzo de 1965. c.662. Sources cinématographiques Filmothèque Nationale d’Espagne.NO.DO. N° 1157C. 08/03/1965.aguirre Javier, Blanco vertical....

  15. Spatial relationships between lead sources and children's blood lead levels in the urban center of Indianapolis (USA).

    Science.gov (United States)

    Morrison, Deborah; Lin, Qing; Wiehe, Sarah; Liu, Gilbert; Rosenman, Marc; Fuller, Trevor; Wang, Jane; Filippelli, Gabriel

    2013-04-01

    Urban children remain disproportionately at risk of having higher blood lead levels than their suburban counterparts. The Westside Cooperative Organization (WESCO), located in Marion County, Indianapolis, Indiana, has a history of children with high blood lead levels as well as high soil lead (Pb) values. This study aims at determining the spatial relationship between soil Pb sources and children's blood lead levels. Soils have been identified as a source of chronic Pb exposure to children, but the spatial scale of the source-recipient relationship is not well characterized. Neighborhood-wide analysis of soil Pb distribution along with a furnace filter technique for sampling interior Pb accumulation for selected homes (n = 7) in the WESCO community was performed. Blood lead levels for children aged 0-5 years during the period 1999-2008 were collected. The study population's mean blood lead levels were higher than national averages across all ages, race, and gender. Non-Hispanic blacks and those individuals in the Wishard advantage program had the highest proportion of elevated blood lead levels. The results show that while there is not a direct relationship between soil Pb and children's blood lead levels at a spatial scale of ~100 m, resuspension of locally sourced soil is occurring based on the interior Pb accumulation. County-wide, the largest predictor of elevated blood lead levels is the location within the urban core. Variation in soil Pb and blood lead levels on the community level is high and not predicted by housing stock age or income. Race is a strong predictor for blood lead levels in the WESCO community. PMID:22782519

  16. Low level rf system for the European Spallation Source's Bilbao linac

    Science.gov (United States)

    Hassanzadegan, Hooman; Garmendia, Nagore; Etxebarria, Victor; Bermejo, F. Javier

    2011-05-01

    Design and some performance results of the pulsed digital low level radio frequency (LLRF) for the radio frequency quadrupole (RFQ) systems of Rutherford Appleton Laboratory-front end test stand and the future European Spallation Source Bilbao linac are presented. For rf field regulation, the design is based on direct rf-to-baseband conversion using an analog in-phase quadrature (IQ) demodulator, high-speed sampling of the I/Q components, baseband signal processing in a field-programmable gate array (FPGA), conversion to analog, and IQ modulation. This concept leads to a simple and versatile LLRF system which can be used for a large variety of rf frequencies and virtually any LLRF application including cw, ramping, and pulsed. In order to improve the accuracy of the probe voltage measurement, errors associated with the use of analog IQ demodulators have been identified and corrected by FPGA algorithms and proper setting of the feedback loop parameters. Furthermore, a baseband-equivalent model for the rf plant is developed in MATLAB-Simulink to study the RFQ transient response under beam loading in the presence of phase and delay errors. The effect of the unwanted resonant modes on the feedback loop stability and the LLRF considerations to avoid such instabilities are discussed and compared to some other machines such as the ILC and the European free electron laser . The practical results obtained from tests with a mock-up cavity and an RFQ cold model verify that amplitude and phase stabilities down to a fraction of one percent and one degree and phase margins larger than ±50° can be achieved with this method preserving the linearity and bandwidth of the feedback loops.

  17. Design of Dictionary-Source Instruction for Levels 1-16 of the SWRL Spelling Programs.

    Science.gov (United States)

    Cronnell, Bruce; Becher, Susan

    One outcome area in the Southwest Regional Laboratory (SWRL) Spelling Program is the use of sources (e.g. a dictionary) to determine the correct spelling of words having unpredictable but common sound-to-spelling correspondences. This paper describes the dictionary-source instruction used in commercially available spelling series and the materials…

  18. An API-based search system for one click access to information

    NARCIS (Netherlands)

    Ionita, Dan; Tax, Niek; Hiemstra, Djoerd

    2013-01-01

    This paper proposes a prototype One Click access system, based on previous work in the field and the related 1CLICK-2@NTCIR10 task. The proposed solution integrates methods from into a three tier algorithm: query categorization, information extraction and output generation and offers suggestions on

  19. On-Surface Synthesis by Click Chemistry Investigated by STM and XPS

    DEFF Research Database (Denmark)

    Vadapoo, Sundar Raja

    2014-01-01

    molecular electronics and surface functionalization. In this thesis, a well-defined click chemistry approach is followed, with the study of azide-alkyne cycloaddition on Cu(111) surface in UHV environment. A successful achievement of the click reaction product via on-surface synthesis has been shown, which...

  20. Sex and Ear Differences in Spontaneous and Click-Evoked Otoacoustic Emissions in Young Adults

    Science.gov (United States)

    Snihur, Adrian W. K.; Hampson, Elizabeth

    2011-01-01

    Effects of sex and handedness on the production of spontaneous and click-evoked otoacoustic emissions (OAEs) were explored in a non-hearing impaired population (ages 17-25 years). A sex difference in OAEs, either produced spontaneously (spontaneous OAEs or SOAEs) or in response to auditory stimuli (click-evoked OAEs or CEOAEs) has been reported in…

  1. Comparing click-through data to purchase decisions for retrieval evaluation

    NARCIS (Netherlands)

    K. Hofmann; B. Huurnink; M. Bron; M. de Rijke

    2010-01-01

    Traditional retrieval evaluation uses explicit relevance judgments which are expensive to collect. Relevance assessments inferred from implicit feedback such as click-through data can be collected inexpensively, but may be less reliable. We compare assessments derived from click-through data to anot

  2. Improved Thermal-Vacuum Compatible Flat Plate Radiometric Source For System-Level Testing Of Optical Sensors

    Science.gov (United States)

    Schwarz, Mark A.; Kent, Craig J.; Bousquet, Robert; Brown, Steven W.

    2016-01-01

    In this work, we describe an improved thermal-vacuum compatible flat plate radiometric source which has been developed and utilized for the characterization and calibration of remote optical sensors. This source is unique in that it can be used in situ, in both ambient and thermal-vacuum environments, allowing it to follow the sensor throughout its testing cycle. The performance of the original flat plate radiometric source was presented at the 2009 SPIE1. Following the original efforts, design upgrades were incorporated into the source to improve both radiometric throughput and uniformity. The pre-thermal-vacuum (pre-TVAC) testing results of a spacecraft-level optical sensor with the improved flat plate illumination source, both in ambient and vacuum environments, are presented. We also briefly discuss potential FPI configuration changes in order to improve its radiometric performance.

  3. Levels and major sources of PM2.5 and PM10 in Bangkok Metropolitan Region.

    Science.gov (United States)

    Chuersuwan, Nares; Nimrat, Subuntith; Lekphet, Sukanda; Kerdkumrai, Tida

    2008-07-01

    This research was the first long-term attempt to concurrently measure and identify major sources of both PM(10) and PM(2.5) in Bangkok Metropolitan Region (BMR). Ambient PM(10) and PM(2.5) were evaluated at four monitoring stations and analyzed for elemental compositions, water-soluble ions, and total carbon during February 2002-January 2003. Fifteen chemical elements, four water-soluble ions, and total carbon were analyzed to assist major source identification by a receptor model approach, known as chemical mass balance. PM(10) and PM(2.5) were significantly different (ptraffic location while two separated residential sites were similar. Seasonal difference of PM(10) and PM(2.5) concentrations was distinct between dry and wet seasons. Major source of PM(10) at the traffic site indicated that automobile emissions and biomass burning-related sources contributed approximately 33% each. Automobiles contributed approximately 39 and 22% of PM(10) mass at two residential sites while biomass burning contributed about 36 and 28%. PM(10) from re-suspended soil and cooking sources accounted for 10 to 15% at a residential site. Major sources of PM(2.5) at traffic site were automobile and biomass burning, contributing approximately 32 and 26%, respectively. Biomass burning was the major source of PM(2.5) mass concentrations at residential sites. Meat cooking also accounted for 31% of PM(2.5) mass at a low impact site. Automobile, biomass burning, and road dust were less significant, contributed 10, 6, and 5%, respectively. Major sources identification at some location had difficulty to achieve performance criteria due to limited source profiles. Improved in characterize other sources profiles will help local authority to better air quality. PMID:18258301

  4. Bioorthogonal Click Chemistry-Based Synthetic Cell Glue.

    Science.gov (United States)

    Koo, Heebeom; Choi, Myunghwan; Kim, Eunha; Hahn, Sei Kwang; Weissleder, Ralph; Yun, Seok Hyun

    2015-12-22

    Artificial methods of cell adhesion can be effective in building functional cell complexes in vitro, but methods for in vivo use are currently lacking. Here, a chemical cell glue based on bioorthogonal click chemistry with high stability and robustness is introduced. Tetrazine (Tz) and trans-cyclooctene (TCO) conjugated to the cell surface form covalent bonds between cells within 10 min in aqueous conditions. Glued, homogeneous, or heterogeneous cell pairs remain viable and stably attached in a microfluidic flow channel at a shear stress of 20 dyn cm(-2) . Upon intravenous injection of assembled Jurkat T cells into live mice, fluorescence microscopy shows the trafficking of cell pairs in circulation and their infiltration into lung tissues. These results demonstrate the promising potential of chemically glued cell pairs for various applications ranging from delivering therapeutic cells to studying cell-cell interactions in vivo. PMID:26768353

  5. SNPEVG: a graphical tool for GWAS graphing with mouse clicks

    Directory of Open Access Journals (Sweden)

    Wang Shengwen

    2012-11-01

    Full Text Available Abstract Background Genome-wide association studies (GWAS using single nucleotide polymorphism (SNP markers generate large quantities of tests results. Global and local graphical viewing of the test results is an effective approach to digest and interpret GWAS results. Results SNPEVG is a set of graphical tools for instant global and local viewing and graphing of GWAS results for all chromosomes and for each trait. The current version includes three programs, SNPEVG1, SNPEVG2 and SNPEVG3. SNPEVG1 is a graphical tool for SNP effect viewing of P-values allowing multiple traits. The total number of graphs that can be generated by one ‘Run’ is n(c + 2, where n is number of ‘traits’ with 0 Conclusions The SNPEVG package is a versatile, flexible and efficient graphical tool for rapid digestion of large quantities of GWAS results with mouse clicks.

  6. Functional graphene by thiol-ene click chemistry.

    Science.gov (United States)

    Luong, Nguyen Dang; Sinh, Le Hoang; Johansson, Leena-Sisko; Campell, Joseph; Seppälä, Jukka

    2015-02-16

    Thiol-ene click reaction was successfully employed for chemical modification of graphene oxide (GO) by one-step synthesis. Herein, 2,2-azobis(2-methylpropionitrile) (AIBN) was used as thermal catalyst and cysteamine hydrochloride (HS-(CH2 )2 -NH2 HCl) was used as thiol-containing compound, which is incorporated to GO surface upon reaction with the C=C bonds. The hydrochloride acts as protecting group for the amine, which is finally eliminated by adding sodium hydroxide. The modified GO contains both S- and N-containing groups (NS-GO). We found that NS-GO sheets form good dispersion in water, ethanol, and ethylene glycol. These graphene dispersions can be processed into functionalized graphene film. Besides, it was demonstrated that NS-GO was proved to be an excellent host matrix for platinum nanoparticles. The developed method paves a new way for graphene modification and its functional nanocomposites. PMID:25580698

  7. Source term model evaluations for the low-level waste facility performance assessment

    Energy Technology Data Exchange (ETDEWEB)

    Yim, M.S.; Su, S.I. [North Carolina State Univ., Raleigh, NC (United States)

    1995-12-31

    The estimation of release of radionuclides from various waste forms to the bottom boundary of the waste disposal facility (source term) is one of the most important aspects of LLW facility performance assessment. In this work, several currently used source term models are comparatively evaluated for the release of carbon-14 based on a test case problem. The models compared include PRESTO-EPA-CPG, IMPACTS, DUST and NEFTRAN-II. Major differences in assumptions and approaches between the models are described and key parameters are identified through sensitivity analysis. The source term results from different models are compared and other concerns or suggestions are discussed.

  8. Declining Groundwater Levels in North India: Understanding Sources of Irrigation Inefficiency

    Science.gov (United States)

    O'Keeffe, J.; Buytaert, W.; Mijic, A.; Brozovic, N.

    2014-12-01

    Over the last half century, the green revolution has transformed India from a famine-prone, drought-susceptible country, into the world's third largest grain producer and one of the most intensely irrigated regions on the planet. This is in no small part due to the country's vast water resources along with an increase in tubewells and more advanced abstraction methods. While agricultural intensification has had undeniable benefits, it has, and continues to have a significant impact on water resources. Unless solutions which take into consideration the ever evolving socio-economic, hydrological and climatic conditions are found, India's agricultural future looks bleak.This research examines the irrigation behaviour of farmers, using data collected during field work in the State of Uttar Pradesh within the Ganges Basin of North India. Significant differences in farmer behaviour and irrigation practices are highlighted, not only between State districts but between individual farmers. This includes the volume of irrigation water applied and the price paid, as well as differences in the yields of crops produced. Analyses of results suggest that this is due to a number of factors, particularly the source of irrigation water. Study areas which had access to cheaper, but crucially less reliable, canal water were found to invest in more efficient water saving technologies in order to reduce the overall cost of irrigation during periods where less expensive canal water is not available. As a result, overall water use and irrigation cost is lower and yields are higher despite very similar climatic conditions. While cheap canal water is not an option for all farmers, the results show that the introduction of more efficient water saving technologies, despite the significant capital expenditure is a viable option for many farmers and costs can be recovered in a relatively short space of time. In addition, the reduction of declining water levels mean that water is abstracted from

  9. Aerosol Particle Sources Affecting the Swedish Air Quality at Urban and Rural Level.

    OpenAIRE

    Kristensson, Adam

    2005-01-01

    During the last decades anthropogenic aerosol particles have attracted much attention due to their adverse health effects and their influence of climate change, and in Sweden, there are mainly three aerosol sources that affect the air quality; domestic wood combustion, traffic, and long distance transport, which includes new particle formation. This work concerns the characterization of these sources and an estimate of how much they contribute to the aerosol particle number (ToN) and mass con...

  10. Preparation of low level sealed 210Pb source for random pulse generator

    International Nuclear Information System (INIS)

    We have developed the random pulse generator (RPG) that utilizes alpha-particle detection with pin photodiode (PPD). In order to support an expected large market of RPG, a steady production system of weak (about 100 Bq) alpha sealed source is necessary, and, for such alpha-source, 210Pb-210Po source is the best candidate on a viewpoint of environmental radioactivity impact. Two methods for such 210Pb-210Po sealed source preparation, namely direct deposition from isopropyl alcohol solution (IPA solution) of 210Pb-210Po nitrate (D-IPA method) and the 210Pb-210Po hydroxides precipitation (PPT method), were experimentally examined. In the former D-IPA method, an aliquot of IPA solution of 210Pb-210Po nitrate was directly dropped in a sealed cap for PPD and dried by heating. Then, a polycarbonate (PC) solution of 1/1 mixture of dichloromethane and dichloroethane was dropped on the source to make a thin (about 0.1 mg/cm2) film for radioactivity sealed. In the PPT method, 210Pb-210Po hydroxide was filtrated on a PC membrane filter (Nuclipore 0.1 μm) and the membrane filter was dissolved in a 1/1 mixture of dichloromethane and dichloroethane. The sealed 210Pb-210Po sources were prepared directly by dropping an aliquot of the solution into the PPD cap followed by its evaporation. The sealed sources thus prepared were subjected to 1m height fall-down test, air blowing test, and water immersion test. It was confirmed that no radioactive contaminants were coming off from the sealed source through these tests. (author)

  11. Drinking water and pregnancy outcome in central North Carolina: source, amount, and trihalomethane levels.

    OpenAIRE

    Savitz, D A; Andrews, K W; Pastore, L M

    1995-01-01

    In spite of the recognition of potentially toxic chemicals in chlorinated drinking water, few studies have evaluated reproductive health consequences of such exposure. Using data from a case-control study of miscarriage, preterm delivery, and low birth weight in central North Carolina, we evaluated risk associated with water source, amount, and trihalomethane (THM) concentration. Water source was not related to any of those pregnancy outcomes, but an increasing amount of ingested water was as...

  12. IN VITRO UTILIZATION OF NPN SOURCES BY INCREASING LEVELS OF CORN STARCH IN STRAW BASED DIETS

    OpenAIRE

    C. S. ALI, T. KHALIQ1, M. SARWAR, A. JAVAID, M. A. SHAHZAD, M. NISA AND S. ZAKIR2

    2007-01-01

    This study was conducted to investigate the effect of replacement of 50% cottonseed meal (CSM) nitrogen with various non protein nitrogen (NPN) sources i.e. urea (CU), biuret (CB) and diammonium phosphate (CD). The four energy sources were: wheat straw with no corn starch (WS), WS + 20% corn starch, WS + 30% corn starch and WS + 40% corn starch. These substrates were fermented with rumen liquor to measure in vitro dry matter digestibility (DMD), bacterial count and ammonia nitrogen (NH3-N) co...

  13. Levels and source apportionment of children's lead exposure: Could urinary lead be used to identify the levels and sources of children's lead pollution?

    International Nuclear Information System (INIS)

    As a highly toxic heavy metal, the pollution and exposure risks of lead are of widespread concern for human health. However, the collection of blood samples for use as an indicator of lead pollution is not always feasible in most cohort or longitudinal studies, especially those involving children health. To evaluate the potential use of urinary lead as an indicator of exposure levels and source apportionment, accompanying with environmental media samples, lead concentrations and isotopic measurements (expressed as 207Pb/206Pb, 208Pb/206Pb and 204Pb/206Pb) were investigated and compared between blood and urine from children living in the vicinities of a typical coking plant and lead-acid battery factory. The results showed urinary lead might not be a preferable proxy for estimating blood lead levels. Fortunately, urinary lead isotopic measurements could be used as an alternative for identifying the sources of children's lead exposure, which coincided well with the blood lead isotope ratio analysis. - Highlights: • Pb isotopes of environmental media and children's blood and urine were analyzed. • Pb exposure and pollution source were studied in lead-acid battery and coking areas. • Pb isotope ratios in blood and urine were similar to those of food, water and PM. • Urine Pb level may not be used as a proxy for indicating the lead levels in blood. • Urine Pb isotope ratios is an alternative to identify source and exposure pathways. - Urinary lead is not a preferable proxy to estimate blood lead level, but urinary lead isotope ratios could be an alternative for identifying the sources of lead exposure in children

  14. Sources

    OpenAIRE

    2011-01-01

    A. SOURCES STATISTIQUES 1. Statistiques générales Annuaire statistique international, SDN (à partir de 1926). Mémorandum sur le commerce international et sur les balances des paiements, annuel à partir de 1927 (numéros rétrospectifs 1912-1926, 1913-1927), [3 volumes : aperçu général ; balances des paiements ; statistiques du commerce extérieur ; utilise les données nationales disponibles. Très utile]. Annuaire statistique de la France. Annuaire statistique de la Belgique. Statistiques économi...

  15. Sources

    OpenAIRE

    2013-01-01

    I–SOURCES MANUSCRITES Archivio di Stato di Roma (ASR) Presidenza dell’Annona e Grascia : bb. 67-68, Lista dei misuratori del grano, 1658-1660. bb. 352-377, Nota dei grani introdotti e venduti in Roma, 1657-1715. bb. 412-419, Ristretto delle assegne dei grani date dai mercanti, 1680-1687. b. 1470, Registro delle lettere del Prefetto dell’Annona, 1659-1660. b. 1706, Libri di entrata e uscita dei grani dell’abbondanza (Ripetta), 16581670. bb. 1930-1931, Debiti e crediti dei fornai, 1658-1660. b....

  16. Sources

    OpenAIRE

    2014-01-01

    Sources éditées : ABADAL i de VINYALS, Ramon d', Catalunya carolingia, II, Els diplomes carolingis a Catalunya, 2 vol., Barcelone, 1926-1952, cit. CC. ACHERY, D', Luc, Spicilegium sive collectio veterum aliquot scriptorum..., E. Baluze et E. Martène éd., Paris, 1723, tome 3. ALART, Bernard, Privilèges et titres relatifs aux franchises, institutions et propriétés communales de Roussillon et de Cerdagne depuis le xie siècle jusqu 'à l'an 1660... Première partie, Perpignan, 1878. ALART, Bernard,...

  17. Daily bioaccessible levels of selected essential but toxic heavy metals from the consumption of non-dietary food sources.

    Science.gov (United States)

    Tongesayi, Tsanangurayi; Fedick, Patrick; Lechner, Lauren; Brock, Christiana; Le Beau, Arielle; Bray, Chelsea

    2013-12-01

    Researchers and regulatory bodies tend to focus on non-essential toxic elements when testing for inorganic chemical pollutants in food. Both toxic and essential elements are increasingly getting into the food chain from the extensive use agrochemicals and the use of contaminated water, raw sewage and untreated industrial effluent to irrigate crops. A holistic testing protocol for chemical contaminants in food should be the norm in order to protect human health, especially considering that the essential elements are as a matter of fact essential poisons. They are essential but are toxic above certain thresholds. Eating contaminated foods that are not considered to be dietary sources of the essential poisons may result in an inadvertent overdose, especially considering that consumers may be taking food supplements that recommended as sources of the essential elements. We measured the levels of manganese and zinc in rice and calculated the daily bioaccessible levels of the two elements. The daily bioaccessible levels were significantly higher than the recommended daily intakes in most of the samples. It has to be noted that exposure from various sources is additive, therefore, lower levels than recommended limits in one source may not guarantee safety from a particular chemical toxicant. PMID:23994087

  18. Design of Three-Phase Three-Level CIC T-Source Inverter with Maximum Boost Control

    DEFF Research Database (Denmark)

    Shults, Tatiana; Husev, Oleksandr; Roncero-Clemente, Carlos;

    2015-01-01

    This paper presents guidelines for component design of the three-level three-phase T-source inverter with continuous input current under maximum boost control proposed recently. Steady state analysis under low-frequency current and voltage ripples in the dc side was made. Component sizes for both...

  19. Low levels of H2S may replace sulfate as sulfur source in sulfate-deprived onion

    NARCIS (Netherlands)

    Durenkamp, Mark; De Kok, LJ

    2005-01-01

    Onion (Allium cepa L.) was exposed to low levels of H2S in order to investigate to what extent H2S could be used as a sulfur source for growth under sulfate-deprived conditions. Sulfate deprivation for a two-week period resulted in a decreased biomass production of the shoot, a subsequently decrease

  20. Effect of different sulfur levels from various sources on brassica napus growth and soil sulfur fractions

    International Nuclear Information System (INIS)

    A two year field study was conducted at two different locations in northern rain fed Punjab, Pakistan to assess the effect of different rates of sulfur application from various sources on soil sulfur fractions and growth of Brassica napus. The treatments included three sulfur sources i. e., single super phosphate, ammonium sulfate and gypsum each applied at five different rates (0, 10, 20, 30 and 40 kg S ha/sup -1/ ). Sulfur application had a significant positive effect on the growth and yield parameters of Brassica napus. Among the sulfur sources ammonium sulfate resulted in maximum increase in plant growth and yield parameters, followed by single super phosphate. Sulfur content and uptake by crop plants was significantly higher with ammonium sulfate application as compared to other two sulfur sources. Sulfur application also exerted a significant positive effect on different S fractions in the soils. On an average, 18.0% of the applied sulfur got incorporated into CaCl/sub 2/ extractable sulfur fraction, while 15.6% and 35.5% entered into adsorbed and organic sulfur fractions in the soils, respectively. The value cost ratio increased significantly by sulfur application up to 30 kg ha/sup -1/. Among sulfur sources, ammonium sulfate performed best giving the highest net return. (author)

  1. Unraveling the sources of ground level ozone in the Intermountain Western United States using Pb isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Christensen, John N. [Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Weiss-Penzias, Peter [University of California at Santa Cruz, Santa Cruz, CA (United States); Fine, Rebekka [University of Nevada, Reno, NV (United States); McDade, Charles E.; Trzepla, Krystyna [University of California at Davis, Crocker Nuclear Laboratory, Davis, CA (United States); Brown, Shaun T. [Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Gustin, Mae Sexauer [University of Nevada, Reno, NV (United States)

    2015-10-15

    Ozone as an atmospheric pollutant is largely produced by anthropogenic precursors and can significantly impact human and ecosystem health, and climate. The U.S. Environmental Protection Agency has recently proposed lowering the ozone standard from 75 ppbv (MDA8 = Maximum Daily 8-Hour Average) to between 65 and 70 ppbv. This will result in remote areas of the Intermountain West that includes many U.S. National Parks being out of compliance, despite a lack of significant local sources. We used Pb isotope fingerprinting and back-trajectory analysis to distinguish sources of imported ozone to Great Basin National Park in eastern Nevada. During discrete Chinese Pb events (> 1.1 ng/m{sup 3} & > 80% Asian Pb) trans-Pacific transported ozone was 5 ± 5.5 ppbv above 19 year averages for those dates. In contrast, concentrations during regional transport from the Los Angeles and Las Vegas areas were 15 ± 2 ppbv above the long-term averages, and those characterized by high-altitude transport 3 days prior to sampling were 19 ± 4 ppbv above. However, over the study period the contribution of trans-Pacific transported ozone increased at a rate of 0.8 ± 0.3 ppbv/year, suggesting that Asian inputs will exceed regional and high altitude sources by 2015–2020. All of these sources will impact regulatory compliance with a new ozone standard, given increasing global background. - Highlights: • Ozone can significantly impact human and ecosystem health and climate. • Pb isotopes and back-trajectory analysis were used to distinguish sources of O{sub 3}. • Baseline concentrations in the Western US are ~ 54 ppbv. • During discrete Asia events O{sub 3} increased by 5 ± 5.5 ppbv and during S CA events by 15 ± 2 ppbv. • Data indicate that Asian ozone inputs will exceed other sources by 2015–2020.

  2. Unraveling the sources of ground level ozone in the Intermountain Western United States using Pb isotopes

    International Nuclear Information System (INIS)

    Ozone as an atmospheric pollutant is largely produced by anthropogenic precursors and can significantly impact human and ecosystem health, and climate. The U.S. Environmental Protection Agency has recently proposed lowering the ozone standard from 75 ppbv (MDA8 = Maximum Daily 8-Hour Average) to between 65 and 70 ppbv. This will result in remote areas of the Intermountain West that includes many U.S. National Parks being out of compliance, despite a lack of significant local sources. We used Pb isotope fingerprinting and back-trajectory analysis to distinguish sources of imported ozone to Great Basin National Park in eastern Nevada. During discrete Chinese Pb events (> 1.1 ng/m3 & > 80% Asian Pb) trans-Pacific transported ozone was 5 ± 5.5 ppbv above 19 year averages for those dates. In contrast, concentrations during regional transport from the Los Angeles and Las Vegas areas were 15 ± 2 ppbv above the long-term averages, and those characterized by high-altitude transport 3 days prior to sampling were 19 ± 4 ppbv above. However, over the study period the contribution of trans-Pacific transported ozone increased at a rate of 0.8 ± 0.3 ppbv/year, suggesting that Asian inputs will exceed regional and high altitude sources by 2015–2020. All of these sources will impact regulatory compliance with a new ozone standard, given increasing global background. - Highlights: • Ozone can significantly impact human and ecosystem health and climate. • Pb isotopes and back-trajectory analysis were used to distinguish sources of O3. • Baseline concentrations in the Western US are ~ 54 ppbv. • During discrete Asia events O3 increased by 5 ± 5.5 ppbv and during S CA events by 15 ± 2 ppbv. • Data indicate that Asian ozone inputs will exceed other sources by 2015–2020

  3. Long pulse H- beam extraction with a rf driven ion source on a high power level

    International Nuclear Information System (INIS)

    IPP Garching is investigating the applicability of rf driven negative ion sources for the neutral beam injection of International Thermonuclear Experimental Reactor. The setup of the tested source was improved to enable long pulses up to 100 kW rf power. The efficiency of negative ion production decreases at high power. The extracted H- currents as well as the symmetry of the plasma density close to the plasma grid and of the beam divergence depend on the magnetic filter field. The pulse duration is limited by the increase in coextracted electrons, which depends on the rf power and the caesium conditions on the plasma grid.

  4. Click-based echolocation in bats: not so primitive after all.

    Science.gov (United States)

    Yovel, Yossi; Geva-Sagiv, Maya; Ulanovsky, Nachum

    2011-05-01

    Echolocating bats of the genus Rousettus produce click sonar signals, using their tongue (lingual echolocation). These signals are often considered rudimentary and are believed to enable only crude performance. However, the main argument supporting this belief, namely the click's reported long duration, was recently shown to be an artifact. In fact, the sonar clicks of Rousettus bats are extremely short, ~50-100 μs, similar to dolphin vocalizations. Here, we present a comparison between the sonar systems of the 'model species' of laryngeal echolocation, the big brown bat (Eptesicus fuscus), and that of lingual echolocation, the Egyptian fruit bat (Rousettus aegyptiacus). We show experimentally that in tasks, such as accurate landing or detection of medium-sized objects, click-based echolocation enables performance similar to laryngeal echolocators. Further, we describe a sophisticated behavioral strategy for biosonar beam steering in clicking bats. Finally, theoretical analyses of the signal design--focusing on their autocorrelations and wideband ambiguity functions--predict that in some aspects, such as target ranging and Doppler-tolerance, click-based echolocation might outperform laryngeal echolocation. Therefore, we suggest that click-based echolocation in bats should be regarded as a viable echolocation strategy, which is in fact similar to the biosonar used by most echolocating animals, including whales and dolphins. PMID:21465138

  5. Drivers of sea-level change - using relative sea level records from the North and South Atlantic to fingerprint sources of mid-Holocene ice melt

    Science.gov (United States)

    Horton, B.; Khan, N.; Ashe, E.; Kopp, R. E.; Long, A. J.; Gehrels, W. R.

    2015-12-01

    Many factors give rise to relative sea-level (RSL) changes that are far from globally uniform. For example, spatially variable sea-level responses arise because of the exchange of mass between ice sheets and oceans. Gravitational, flexural, and rotational processes generate a distinct spatial pattern - or "fingerprint" - of sea-level change associated with each shrinking land ice mass. As a land ice mass shrinks, sea-level rise is greater in areas geographically distal to the ice mass than in areas proximal to it, in large part because the gravitational attraction between the ice mass and the ocean is reduced. Thus, the U.S. mid-Atlantic coastline experiences about 50% of the global average sea-level-rise due to Greenland Ice Sheet melt, but about 120% of the global average due to West Antarctic Ice Sheet melt. Separating the Greenland and Antarctic ice sheet contributions during the past 7,000 years requires analysis of sea-level changes from sites in the northern and southern hemisphere. Accordingly we present sea-level records within a hierarchical statistical modeling to: (1) quantify rates of change; (2) compare rates of change among sites, including full quantification of the uncertainty in their differences; and (3) test hypotheses about the sources of meltwater through their sea-level fingerprints. Preliminary analysis of three sites within our North and South Atlantic sea-level database indicates sea-level gradient in the rate of RSL rise during the mid Holocene between 6000 and 4000 years BP; a greater change in rate is found in Brazil than St Croix than New Jersey, consistent with an increase and then decrease in Greenland Ice Sheet mass.

  6. Policy Transfer Among Regional-Level Organizations: Insights from Source Water Protection in Ontario.

    Science.gov (United States)

    de Loë, R C; Murray, D; Michaels, S; Plummer, R

    2016-07-01

    Organizations at the local and regional scales often face the challenge of developing policy mechanisms rapidly and concurrently, whether in response to expanding mandates, newly identified threats, or changes in the political environment. In the Canadian Province of Ontario, rapid, concurrent policy development was considered desirable by 19 regional organizations tasked with developing policies for protection of drinking water sources under very tight and highly prescribed mandates. An explicit policy transfer approach was used by these organizations. Policy transfer refers to using knowledge of policies, programs, and institutions in one context in the development of policies, programs, and institutions in another. This paper assesses three online mechanisms developed to facilitate policy transfer for source water protection in Ontario. Insights are based on a survey of policy planners from the 19 regional organizations who used the three policy transfer tools, supplemented by an analysis of three policies created and transferred among the 19 regional source water protection organizations. Policy planners in the study indicated they had used policy transfer to develop source protection policies for their regions-a finding confirmed by analysis of the text of policies. While the online policy transfer tools clearly facilitated systematic policy transfer, participants still preferred informal, direct exchanges with their peers in other regions over the use of the internet-based policy transfer mechanisms created on their behalf. PMID:27094441

  7. A Comparison of the Burnout Levels of Teachers with Different Occupational Satisfaction Sources

    Science.gov (United States)

    Akbaba, Sirri

    2014-01-01

    The aim of this research is to investigate whether professional satiety sources predict burnout in teachers. Professional values, including satisfaction and dissatisfaction with the teaching profession, are investigated using the Professional Satiety Inventory. Of 698 teachers, 478 primary school teachers were chosen randomly as the research…

  8. Policy Transfer Among Regional-Level Organizations: Insights from Source Water Protection in Ontario

    Science.gov (United States)

    de Loë, R. C.; Murray, D.; Michaels, S.; Plummer, R.

    2016-07-01

    Organizations at the local and regional scales often face the challenge of developing policy mechanisms rapidly and concurrently, whether in response to expanding mandates, newly identified threats, or changes in the political environment. In the Canadian Province of Ontario, rapid, concurrent policy development was considered desirable by 19 regional organizations tasked with developing policies for protection of drinking water sources under very tight and highly prescribed mandates. An explicit policy transfer approach was used by these organizations. Policy transfer refers to using knowledge of policies, programs, and institutions in one context in the development of policies, programs, and institutions in another. This paper assesses three online mechanisms developed to facilitate policy transfer for source water protection in Ontario. Insights are based on a survey of policy planners from the 19 regional organizations who used the three policy transfer tools, supplemented by an analysis of three policies created and transferred among the 19 regional source water protection organizations. Policy planners in the study indicated they had used policy transfer to develop source protection policies for their regions—a finding confirmed by analysis of the text of policies. While the online policy transfer tools clearly facilitated systematic policy transfer, participants still preferred informal, direct exchanges with their peers in other regions over the use of the internet-based policy transfer mechanisms created on their behalf.

  9. Exploring the Relationship between Certification Sources, Experience Levels, and Classroom Management Orientations of Classroom Teachers

    Science.gov (United States)

    Ritter, Janice Toterhi; Hancock, Dawson R.

    2007-01-01

    Teachers continue to report that classroom management is one of their greatest challenges in the classroom. Classroom management involves teacher's efforts to oversee classroom activities such as learning, social interaction, and student behavior. In this study, we examined the relationship between sources of teachers' certification (traditional…

  10. Comparison of methionine sources around requirement levels using a methionine efficacy method in 0 to 28 day old broilers.

    Science.gov (United States)

    Agostini, P S; Dalibard, P; Mercier, Y; Van der Aar, P; Van der Klis, J D

    2016-03-01

    The addition of methionine in the poultry feed industry is still facing the relative efficacy dilemma between DL-methionine (DLM) and hydroxy-methionine (HMTBA). The aim of this study was to compare the effect of dietary DLM and HMTBA on broiler performance at different levels of total sulfur amino acids (TSAA). The treatments consisted of a basal diet without methionine addition, and 4 increasing methionine doses for both sources resulting in TSAA/Lysine ratios from 0.62 to 0.73 in the starter phase and 0.59 to 0.82 in the grower phase. The comparison of product performance was performed by three-way ANOVA analysis and by methionine efficacy calculation as an alternative method of comparison. Growth results obtained during the starter phase with the different methionine supplementations did not show significant growth responses to TSAA levels, indicating a lower methionine requirement in the starter phase than currently assumed. However, a significant methionine dose effect was obtained for the period 10 to 28 day of age and for the entire growth period of 0 to 28 day of age. Excepting a significant gender effect, the statistical analysis did not allow for the discrimination of methionine sources, and no interaction between source and dose level was observed up to 28 days of age. A significant interaction between source and dose level was observed for methionine efficacy for the grower phase, and the total growth period showed better HMTBA efficacy at higher TSAA value. The exponential model fitted to each methionine source for body weight response depending on methionine intake or for feed conversion ratio (FCR) depending on methionine doses did not allow the methionine sources to be distinguished. Altogether, these results conclude that methionine sources lead to similar performances response when compared at TSAA values around the broiler requirement level. These results also showed that at TSAA values above requirement, HMTBA had a better methionine efficacy

  11. Comparative Analysis of Click Chemistry Mediated Activity-Based Protein Profiling in Cell Lysates

    Directory of Open Access Journals (Sweden)

    Yinliang Yang

    2013-10-01

    Full Text Available Activity-based protein profiling uses chemical probes that covalently attach to active enzyme targets. Probes with conventional tags have disadvantages, such as limited cell permeability or steric hindrance around the reactive group. A tandem labeling strategy with click chemistry is now widely used to study enzyme targets in situ and in vivo. Herein, the probes are reacted in live cells, whereas the ensuing detection by click chemistry takes place in cell lysates. We here make a comparison of the efficiency of the activity-based tandem labeling strategy by using Cu(I-catalyzed and strain-promoted click chemistry, different ligands and different lysis conditions.

  12. Directionality of sperm whale sonar clicks and its relation to piston radiation theory

    DEFF Research Database (Denmark)

    Beedholm, K.; Møhl, Bertel

    2006-01-01

    This paper investigates the applicability to sperm whales of the theory of sound radiating from a piston. The theory is applied to a physical model and to a series of sperm whale clicks. Results show that wave forms of off-axis signals can be reproduced by convolving an on-axis signal with the...... spatial impulse response of a piston. The angle of a recorded click can be estimated as the angle producing the spatial impulse response that gives the best match with the observation when convolved with the on-axis wave form. It is concluded that piston theory applies to sperm whale sonar click emission....

  13. Sediment baseline study of levels and sources of polycyclic aromatic hydrocarbons and heavy metals in Lake Nicaragua

    DEFF Research Database (Denmark)

    Scheibye, Katrine; Weisser, Johan; Borggaard, Ole K.;

    2014-01-01

    Selected metals and polycyclic aromatic hydrocarbons (PAHs) were analyzed in sediment samples from 24 sites in Lake Nicaragua sampled May 2010 to provide a baseline of pollution levels. Cu exceeded the Consensus-Based Sediment Quality Guideline (CBSQG) Threshold Effect Concentrations (TECs) at 21.......g., creosote). The main sources of PAHs in Lake Nicaragua were determined as of diffuse petrogenic and pyrogenic origin as well as diagenetic produced perylene. The relative importance of these PAH sources was determined by interpretation of loading and score plots from a principal component analysis. This...... study concluded that areas of Lake Nicaragua represent an important pollution baseline for future studies in this lake and other tropical lakes....

  14. Atmospheric polychlorinated biphenyls in Indian cities: levels, emission sources and toxicity equivalents.

    Science.gov (United States)

    Chakraborty, Paromita; Zhang, Gan; Eckhardt, Sabine; Li, Jun; Breivik, Knut; Lam, Paul K S; Tanabe, Shinsuke; Jones, Kevin C

    2013-11-01

    Atmospheric concentration of Polychlorinated biphenyls (PCBs) were measured on diurnal basis by active air sampling during Dec 2006 to Feb 2007 in seven major cities from the northern (New Delhi and Agra), eastern (Kolkata), western (Mumbai and Goa) and southern (Chennai and Bangalore) parts of India. Average concentration of Σ25PCBs in the Indian atmosphere was 4460 (± 2200) pg/m(-3) with a dominance of congeners with 4-7 chlorine atoms. Model results (HYSPLIT, FLEXPART) indicate that the source areas are likely confined to local or regional proximity. Results from the FLEXPART model show that existing emission inventories cannot explain the high concentrations observed for PCB-28. Electronic waste, ship breaking activities and dumped solid waste are attributed as the possible sources of PCBs in India. Σ25PCB concentrations for each city showed significant linear correlation with Toxicity equivalence (TEQ) and Neurotoxic equivalence (NEQ) values. PMID:23954623

  15. A hybrid algorithm for stochastic single-source capacitated facility location problem with service level requirements

    Directory of Open Access Journals (Sweden)

    Hosseinali Salemi

    2016-04-01

    Full Text Available Facility location models are observed in many diverse areas such as communication networks, transportation, and distribution systems planning. They play significant role in supply chain and operations management and are one of the main well-known topics in strategic agenda of contemporary manufacturing and service companies accompanied by long-lasting effects. We define a new approach for solving stochastic single source capacitated facility location problem (SSSCFLP. Customers with stochastic demand are assigned to set of capacitated facilities that are selected to serve them. It is demonstrated that problem can be transformed to deterministic Single Source Capacitated Facility Location Problem (SSCFLP for Poisson demand distribution. A hybrid algorithm which combines Lagrangian heuristic with adjusted mixture of Ant colony and Genetic optimization is proposed to find lower and upper bounds for this problem. Computational results of various instances with distinct properties indicate that proposed solving approach is efficient.

  16. Human internal and external exposure to PBDEs--a review of levels and sources

    DEFF Research Database (Denmark)

    Frederiksen, Marie; Vorkamp, Katrin; Thomsen, Marianne; Knudsen, Lisbeth E

    2009-01-01

    This paper reviews the existing literature on human exposure to polybrominated diphenyl ethers (PBDEs), with particular focus on external exposure routes (e.g. dust, diet, and air) and the resulting internal exposure to PBDEs (e.g. breast milk and blood). Being lipophilic and persistent organic...... use may lead to some additional exposure in the home environment. Dust seem to be an aggregate of the indoor source, and the ingestion of dust conveys the highest intake of BDE-209 of all sources, possibly also of other PBDE congeners. The PBDE exposure through dust is significant for toddlers who...... were found in the UK than in continental Europe. Recent studies have shown that BDE-209 also accumulates in humans. A shift in congener composition from maternal to umbilical cord blood has been observed in several cases. A shift has also been observed for BDE-209, which is present in larger ratios in...

  17. Urban background levels of particle number concentration and sources in Vilnius, Lithuania

    Science.gov (United States)

    Byčenkienė, Steigvilė; Plauškaitė, Kristina; Dudoitis, Vadimas; Ulevicius, Vidmantas

    2014-06-01

    This study presents results of research on urban aerosol particles with a focus on the aerosol particle number concentration (PNC) and the particle size distribution. The real time measurements of aerosol PNC (> 4.5 nm) and number size distributions (9-840 nm) were performed. The seasonal variations essentially comprised the minimum monthly mean in October 2010 (3400 ± 3000 cm- 3) and the maximum in April 2011 (19,000 ± 15,000 cm- 3). The mean annual PNC was 10,000 ± 8000 cm- 3 with an average mode size of 30-50 nm. The presence of strong diurnal patterns in aerosol PNC was evident as a direct effect of three sources of aerosol particles (nucleation, traffic, and residential heating). Hybrid receptor modeling potential source contribution function (PSCF) and concentration weighted trajectory (CWT) were used by incorporating 72-h backward trajectories and measurements of PNC in Vilnius. The results of trajectory clustering and the PSCF method demonstrated that possible additional source areas contributing to the elevated particle number concentration in Vilnius could be industrial areas in central Europe. Principal component analysis (PCA) revealed highest loadings for PNC, PM10, NOx, NO, NO2 and SO2 concentrations, indicating combustion processes occurring in vehicle engines and use of sulfur-containing fossil fuels for residential heating.

  18. Evaluating Search Engine Relevance with Click-Based Metrics

    Science.gov (United States)

    Radlinski, Filip; Kurup, Madhu; Joachims, Thorsten

    Automatically judging the quality of retrieval functions based on observable user behavior holds promise for making retrieval evaluation faster, cheaper, and more user centered. However, the relationship between observable user behavior and retrieval quality is not yet fully understood. In this chapter, we expand upon, Radlinski et al. (How does clickthrough data reflect retrieval quality, In Proceedings of the ACM Conference on Information and Knowledge Management (CIKM), 43-52, 2008), presenting a sequence of studies investigating this relationship for an operational search engine on the arXiv.org e-print archive. We find that none of the eight absolute usage metrics we explore (including the number of clicks observed, the frequency with which users reformulate their queries, and how often result sets are abandoned) reliably reflect retrieval quality for the sample sizes we consider. However, we find that paired experiment designs adapted from sensory analysis produce accurate and reliable statements about the relative quality of two retrieval functions. In particular, we investigate two paired comparison tests that analyze clickthrough data from an interleaved presentation of ranking pairs, and find that both give accurate and consistent results. We conclude that both paired comparison tests give substantially more accurate and sensitive evaluation results than the absolute usage metrics in our domain.

  19. Detection of systolic ejection click using time growing neural network.

    Science.gov (United States)

    Gharehbaghi, Arash; Dutoit, Thierry; Ask, Per; Sörnmo, Leif

    2014-04-01

    In this paper, we present a novel neural network for classification of short-duration heart sounds: the time growing neural network (TGNN). The input to the network is the spectral power in adjacent frequency bands as computed in time windows of growing length. Children with heart systolic ejection click (SEC) and normal children are the two groups subjected to analysis. The performance of the TGNN is compared to that of a time delay neural network (TDNN) and a multi-layer perceptron (MLP), using training and test datasets of similar sizes with a total of 614 normal and abnormal cardiac cycles. From the test dataset, the classification rate/sensitivity is found to be 97.0%/98.1% for the TGNN, 85.1%/76.4% for the TDNN, and 92.7%/85.7% for the MLP. The results show that the TGNN performs better than do TDNN and MLP when frequency band power is used as classifier input. The performance of TGNN is also found to exhibit better immunity to noise. PMID:24613501

  20. Predicting user click behaviour in search engine advertisements

    Science.gov (United States)

    Daryaie Zanjani, Mohammad; Khadivi, Shahram

    2015-10-01

    According to the specific requirements and interests of users, search engines select and display advertisements that match user needs and have higher probability of attracting users' attention based on their previous search history. New objects such as user, advertisement or query cause a deterioration of precision in targeted advertising due to their lack of history. This article surveys this challenge. In the case of new objects, we first extract similar observed objects to the new object and then we use their history as the history of new object. Similarity between objects is measured based on correlation, which is a relation between user and advertisement when the advertisement is displayed to the user. This method is used for all objects, so it has helped us to accurately select relevant advertisements for users' queries. In our proposed model, we assume that similar users behave in a similar manner. We find that users with few queries are similar to new users. We will show that correlation between users and advertisements' keywords is high. Thus, users who pay attention to advertisements' keywords, click similar advertisements. In addition, users who pay attention to specific brand names might have similar behaviours too.

  1. Click Chemistry Immobilization of Antibodies on Polymer Coated Gold Nanoparticles.

    Science.gov (United States)

    Finetti, Chiara; Sola, Laura; Pezzullo, Margherita; Prosperi, Davide; Colombo, Miriam; Riva, Benedetta; Avvakumova, Svetlana; Morasso, Carlo; Picciolini, Silvia; Chiari, Marcella

    2016-07-26

    The goal of this work is to develop an innovative approach for the coating of gold nanoparticles (AuNPs) with a synthetic functional copolymer. This stable coating with a thickness of few nanometers provides, at the same time, stabilization and functionalization of the particles. The polymeric coating consists of a backbone of polydimethylacrylamide (DMA) functionalized with an alkyne monomer that allows the binding of azido modified molecules by Cu(I)-catalyzed azide/alkyne 1,3-dipolar cycloaddition (CuAAC, click chemistry). The thin polymer layer on the surface stabilizes the colloidal suspension whereas the alkyne functions pending from the backbone are available for the reaction with azido-modified proteins. The reactivity of the coating is demonstrated by immobilizing an azido modified anti-mouse IgG antibody on the particle surface. This approach for the covalent binding of antibody to a gold-NPs is applied to the development of gold labels in biosensing techniques. PMID:27367748

  2. Low fouling polysulfone ultrafiltration membrane via click chemistry

    KAUST Repository

    Xie, Yihui

    2014-10-13

    Hydrophilic surfaces are known to be less prone to fouling. Ultrafiltration membranes are frequently prepared from rather hydrophobic polymers like polysulfone (PSU). Strategies to keep the good pore forming characteristics of PSU, but with improved hydrophilicity are proposed here. PSU functionalized with 1,2,3-triazole ring substituents containing OH groups was successfully synthesized through click chemistry reaction. The structures of the polymers were confirmed using NMR spectroscopy and Fourier transform infrared spectroscopy (FTIR). High thermal stability (>280°C) was observed by thermal gravimetric analysis. Elemental analysis showed the presence of nitrogen containing triazole group with different degrees of functionalization (23%, 49%, 56%, and 94%). The glass transition temperature shifted with the introduction of triazole pendant groups from 190°C (unmodified) to 171°C. Ultrafiltration membranes were prepared via phase inversion by immersion in different coagulation baths (NMP/water mixtures with volume ratios from 0/100 to 40/60). The morphologies of these membranes were studied by field emission scanning electron microscopy (FESEM). The optimized PSU bearing triazole functions membranes exhibited water permeability up to 187 L m-2 h-1 bar-1, which is 23 times higher than those prepared under the same conditions but with unmodified polysulfone (PSU; 8 L m-2 h-1 bar-1). Results of bovine serum albumin protein rejection test indicated that susceptibility to fouling decreased with the modification, due to the increased hydrophilicity, while keeping high protein rejection ratio (>99%).

  3. Harnessing click detectors for the genuine characterization of light states

    Science.gov (United States)

    Heilmann, René; Sperling, Jan; Perez-Leija, Armando; Gräfe, Markus; Heinrich, Matthias; Nolte, Stefan; Vogel, Werner; Szameit, Alexander

    2016-01-01

    The key requirement for harnessing the quantum properties of light is the capability to detect and count individual photons. Of particular interest are photon-number-resolving detectors, which allow one to determine whether a state of light is classical or genuinely quantum. Existing schemes for addressing this challenge rely on a proportional conversion of photons to electrons. As such, they are capable of correctly characterizing small photon fluxes, yet are limited by uncertainties in the conversion rate. In this work, we employ a divide-and-conquer approach to infallibly discerning non-classicality of states of light. This is achieved by transforming the incident fields into uniform spatial distributions that readily lend themselves for characterization by standard on-off detectors. Since the exact statistics of the light stream in multiplexed on-off detectors are click statistics, our technique is freely scalable to accommodate-in principle-arbitrarily large photon fluxes. Our experiments pave the way towards genuine integrated photon-number-resolving detection for advanced on-chip photonic quantum networks.

  4. Common basis of establishing safety standards and other safety decision-making levels for different sources of health risk

    International Nuclear Information System (INIS)

    Current approaches in establishing safety standards and other decision-making levels for different sources of health risk are critically analysed. To have a common basis for this decision-making a specific risk index R is recommended. In the common sense R is quantitatively defined as LLE caused by the annual exposure to the risk source considered: R = annual exposure, damage (LLE) from the exposure unit. This common definition is also rewritten in specific forms for a set of different risk sources (ionising radiation, chemical pollutants, etc): for different risk sources the exposure can be measured with different quantities (the probability of death, the exposure dose, etc.). R is relative LLE: LLE in years referred to 1 year under the risk. The dimension of this value is [year/year]. In the statistical sense R is conditionally the share of the year, which is lost due to exposure to a risk source during this year. In this sense R can be called as the relative damage. Really lifetime years are lost after the exposure. R can be in some conditional sense considered as a dimensionless quantity. General safety standards Rn for the public and occupational workers have been suggested in terms of this index: Rn = 0.0007 and 0.01 accordingly. Secondary safety standards are derived for a number of risk sources (ionising radiation, environmental chemical pollutants, etc). Values of Rn are chosen in such a way that to have the secondary radiation BSS being equivalent to the current one's. Other general and derived levels for safety decision-making are also proposed including the de-minimus levels. Their possible dependence on the national or regional health-demographic data (HDD) is considered. Such issues as the ways of the integration and averaging of risk indices considered through the national or regional HDD for different risk sources and the use of non-threshold linear exposure - response relationships for ionising radiation and chemical pollutants are analysed

  5. Level and source of 129I of environmental samples in Xi'an region, China

    International Nuclear Information System (INIS)

    Iodine-129 is widely used as a tracer in various environmental practices such as monitoring of nuclear environmental safety, seawater exchange and transport, geochemical cycle of stable iodine and dating of geological events. The spatial distribution of 129I concentration varies significantly on global scale because of anthropogenic input from nuclear activities coupled with scarcity of data on environmental 129I variability in many parts of the world including Asia. Here we report new data on 129I and 127I concentrations in soil, vegetation, river water and precipitation collected from Xi'an area, China. The results indicate values for environmental 129I/127I ratios in the investigated area range from 1.1 x 10-10 to 43.5 x 10-10 with a mean of 20.6 x 10-10, which is 1-3 orders of magnitude lower than the ratios observed in Europe, but comparable with those observed in the locations far from direct effect of point release sources and at similar latitude. The main source of 129I in the investigated area is attributed to the global fallout of both atmospheric nuclear weapons testing and long distance dispersion of fuel reprocessing releases. - Research highlights: → We present the first investigation of anthropogenic radioactive 129I in the terrestrial environment in middle China. → River water, surface soil and vegetation samples from Xi'an region were analyzed for 129I and stable 127I. → The distribution, source term, and transfer from soil to plants of 129I in middle China are presented. → AMS shows its unique capacity in 129I analysis and environmental safety research using 129I and other radionuclides. → The results supplied a basic data for evaluating nuclear risk in the future.

  6. Elevated nitrate levels in the groundwater of the Gaza Strip: Distribution and sources

    International Nuclear Information System (INIS)

    Seven years of monitoring groundwater in the Gaza Strip has shown that nitrate was and still is a major groundwater pollutant. The objectives of this research were to study the distribution of NO3- in the groundwater of the Gaza Strip and to identify the sources of NO3- in the Gaza aquifer system by assessing nitrogen and oxygen isotopes. The most recent samples collected in 2007 showed 90% of the wells having NO3- concentrations that are several times higher than the WHO standards of 50 mg/L. Potential NO3- source materials in Gaza are animal manure N, synthetic NH4 based fertilizers, and wastewater/sludge. The average concentrations of N in the sludge, manure and soil of Gaza were 2.9%, 1% and 0.08%, respectively. The range in δ15N of solid manure samples was + 7.5 to + 11.9 per mille. The range in δ15N of sludge samples was + 4.6 to + 7.4 per mille, while four brands of synthetic fertilizers commonly used in Gaza had δ15N ranging from + 0.2 to + 1.0 per mille. Sludge amended soil had δ15N ranging from + 2.0 to + 7.3 per mille. For both δ18O and δ15N, the ranges of groundwater NO3- were - 0.1 to + 9.3 per milleand + 3.2 to 12.8 per mille, respectively. No significant bacterial denitrification is taking place in the Gaza Strip aquifer. Nitrate was predominantly derived from manure and, provided δ15N of sludge represents the maximum δ15N of human waste, to a lesser extent from septic effluents/sludge. Synthetic fertilizers were a minor source

  7. A high-quality multi-level voltage source inverter suitable for high power/high voltage applications

    International Nuclear Information System (INIS)

    In this paper new magnitudes for D C side capacitors' voltages of a multi level voltage source inv enter are presented. Using these magnitudes of D C side capacitors voltage allow generation of Σ3k steps of A C output voltage by cascade connection of only N single-phase full bridge inverter. This subject has resulted in almost sinusoidal output voltage wave form. Approximated equal area pulse amplitude modulation technique is used to calculate the duration of each step of voltage, which has resulted in reduction of complexity of control circuit. A simple closed-loop controller is developed for controlling the voltage of D C side capacitors. Harmonic analysis and capacitor calculations are presented, too. Simulation results have been used to verify the overall operation of the proposed multi level voltage source inverter in feeding a R-L load with a stepped sinusoidal wave form

  8. Drinking water and pregnancy outcome in central North Carolina: source, amount, and trihalomethane levels.

    Science.gov (United States)

    Savitz, D A; Andrews, K W; Pastore, L M

    1995-06-01

    In spite of the recognition of potentially toxic chemicals in chlorinated drinking water, few studies have evaluated reproductive health consequences of such exposure. Using data from a case-control study of miscarriage, preterm delivery, and low birth weight in central North Carolina, we evaluated risk associated with water source, amount, and trihalomethane (THM) concentration. Water source was not related to any of those pregnancy outcomes, but an increasing amount of ingested water was associated with decreased risks of all three outcomes (odds ratios around 1.5 for 0 glasses per day relative to 1-3 glasses per day, falling to 0.8 for 4+ glasses per day). THM concentration and dose (concentration x amount) were not related to pregnancy outcome, with the possible exception of an increased risk of miscarriage in the highest sextile of THM concentration (adjusted odds ratio = 2.8, 95% confidence interval = 1.1-2.7), which was not part of an overall dose-response gradient. These data do not indicate a strong association between chlorination by-products and adverse pregnancy outcome, but given the limited quality of our exposure assessment and the increased miscarriage risk in the highest exposure group, more refined evaluation is warranted. PMID:7556013

  9. Level and source of 129I of environmental samples in Xi'an region, China.

    Science.gov (United States)

    Zhang, Luyuan; Zhou, Weijian; Hou, Xiaolin; Chen, Ning; Liu, Qi; He, Chaohui; Fan, Yukun; Luo, Maoyi; Wang, Zhiwen; Fu, Yunchong

    2011-09-01

    Iodine-129 is widely used as a tracer in various environmental practices such as monitoring of nuclear environmental safety, seawater exchange and transport, geochemical cycle of stable iodine and dating of geological events. The spatial distribution of (129)I concentration varies significantly on global scale because of anthropogenic input from nuclear activities coupled with scarcity of data on environmental (129)I variability in many parts of the world including Asia. Here we report new data on (129)I and (127)I concentrations in soil, vegetation, river water and precipitation collected from Xi'an area, China. The results indicate values for environmental (129)I/(127)I ratios in the investigated area range from 1.1×10(-10) to 43.5×10(-10) with a mean of 20.6×10(-10), which is 1-3 orders of magnitude lower than the ratios observed in Europe, but comparable with those observed in the locations far from direct effect of point release sources and at similar latitude. The main source of (129)I in the investigated area is attributed to the global fallout of both atmospheric nuclear weapons testing and long distance dispersion of fuel reprocessing releases. PMID:21737119

  10. 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.

  11. Click-to-Chelate: Development of Technetium and Rhenium-Tricarbonyl Labeled Radiopharmaceuticals

    Directory of Open Access Journals (Sweden)

    Thomas L. Mindt

    2013-03-01

    Full Text Available The Click-to-Chelate approach is a highly efficient strategy for the radiolabeling of molecules of medicinal interest with technetium and rhenium-tricarbonyl cores. Reaction of azide-functionalized molecules with alkyne prochelators by the Cu(I-catalyzed azide-alkyne cycloaddition (CuAAC; click reaction enables the simultaneous synthesis and conjugation of tridentate chelating systems for the stable complexation of the radiometals. In many cases, the functionalization of (biomolecules with the ligand system and radiolabeling can be achieved by convenient one-pot procedures. Since its first report in 2006, Click-to-Chelate has been applied to the development of numerous novel radiotracers with promising potential for translation into the clinic. This review summarizes the use of the Click-to-Chelate approach in radiopharmaceutical sciences and provides a perspective for future applications.

  12. Fast, copper-free click chemistry: a convenient solid-phase approach to oligonucleotide conjugation

    OpenAIRE

    Singh, Ishwar; Vyle, Joseph S.; Heaney, Frances

    2009-01-01

    Solid-phase oligonucleotide conjugation by nitrile oxide–alkyne click cycloaddition chemistry has been successfully demonstrated; the reaction, compatible with all nucleobases, requires no metal catalyst and proceeds under physiological conditions.

  13. Chemosynthesis of poly(ε-lysine)-analogous polymers by microwave-assisted click polymerization.

    Science.gov (United States)

    Guo, Jinshan; Wei, Ying; Zhou, Dongfang; Cai, Pingqiang; Jing, Xiabin; Chen, Xue-Si; Huang, Yubin

    2011-03-14

    Poly(ε-lysine) (ε-PL)-analogous click polypeptides with not only similar α-amino side groups but also similar main chain to ε-PL were chemically synthesized for the first time through click polymerization from aspartic (or glutamic)-acid-based dialkyne and diazide monomers. With microwave-assisting, the reaction time of click polymerization was compressed into 30 min. The polymers were fully characterized by NMR, ATR-FTIR, and SEC-MALLS analysis. The deprotected click polypeptides had similar pK(a) value (7.5) and relatively low cytotoxicity as ε-PL and could be used as substitutes of ε-PL in biomedical applications, especially in endotoxin selective removal. Poly(ethylene glycol) (PEG)-containing alternating copolymers with α-amino groups were also synthesized and characterized. After deprotection, the polymers could be used as functional gene vector with PEG shadowing system and NCA initiator to get amphiphilic graft polymers. PMID:21302898

  14. Unified System-Level Modeling of Intermittent Renewable Energy Sources and Energy Storage for Power System Operation

    OpenAIRE

    Heussen, Kai; Koch, Stephan; Ulbig, Andreas; Andersson, Goran

    2011-01-01

    The system-level consideration of inter- mittent renewable energy sources and small-scale en- ergy storage in power systems remains a challenge as either type is incompatible with traditional operation concepts. Non-controllability and energy-constraints are still considered contingent cases in market-based operation. The design of operation strategies for up to 100 % renewable energy systems requires an explicit consideration of non-dispatchable generation and stor- age capacities, as well a...

  15. Application of a Double Aza-Michael Reaction in a ‘Click, Click, Cy-Click’ Strategy: From Bench to Flow

    Science.gov (United States)

    Zang, Qin; Javed, Salim; Ullah, Farman; Zhou, Aihua; Knudtson, Christopher A.; Bi, Danse; Basha, Fatima Z.; Organ, Michael G.; Hanson, Paul R.

    2011-01-01

    The development of a ‘click, click, cy-click’ process utilizing a double aza-Michael reaction to generate functionalized 1,2,5-thiadiazepane 1,1-dioxides is reported. Optimization in flow, followed by scale out of the inter-/intramolecular double aza-Michael addition has also been realized using a microwave-assisted, continuous flow organic synthesis platform (MACOS). In addition, a facile one-pot, sequential strategy employing in situ Huisgen cycloaddition post-double aza-Michael has been accomplished, and is applicable to library synthesis. PMID:21927510

  16. Evaluation of the choline status in mink fed different levels and sources of choline

    DEFF Research Database (Denmark)

    Hedemann, Mette Skou; Damgaard, Birthe Marie; Clausen, T.N.;

    2012-01-01

    Choline is an essential nutrient but the daily need for choline in mink has never been determined. Two experiments were performed to evalutate the choline status in mink kits and full-grown mink fed different levels of choline. In the first experiment mink kits were fed a synthetic diet with chol...

  17. Impact of level and source of compost based organic material on the productivity of autumn maize (zea mays l.)

    International Nuclear Information System (INIS)

    Organic manure from different sources could be an effective substitute of chemical fertilizers. Therefore, the present study compares the effect of varying level (0, 2, 4, 6, 8, 10 t ha/sup -1/) of two types of compost, i.e poultry manure compost (PM compost) and press-mud compost (PrM compost) on the yield of maize. The experiment was conducted at Agronomic Research Area, University of Agriculture Faisalabad, Pakistan for two consecutive years 2011 and 2012. Results of this study revealed that all the levels and sources of compost based organic material had significant effect on the yield and yield parameters of autumn maize. Maximum plant height, cob diameter, cob length, cob weight, number of grain rows per cob, number of grains per cob, 1000-grain weight biological yield, grain yield and harvest index were produced by the application of 10 t ha/sup -1/ PM compost. Whereas, the number of cobs per plant was not significantly affected by level and source of compost based organic material. It was concluded that 10 t ha/sup -1/ PM compost could be used lucratively for optimizing maize yield. (author)

  18. Levels and sources of planar and non-planar PCBs in pine needles across Poland.

    Science.gov (United States)

    Falandysz, Jerzy; Orlikowska, Anna; Jarzyńska, Grażyna; Bochentin, Ilona; Wyrzykowska, Barbara; Drewnowska, Małgorzata; Hanari, Nobuyashi; Horii, Yuichi; Yamashita, Nobuyoshi

    2012-01-01

    Under a small project, one-year-old Scots Pine needles collected from 25 spatially distant sites were examined in monitoring the extent of environmental diffusion and possible sources of polychlorinated biphenyls (PCBs) in ambient air, their depositions and uptake by plants in Poland. The congener-specific determination of planar and non-planar chlorobiphenyls was achieved by isotope dilution HRGC-HRMS method after a highly refined extraction on multi-layer column of silica gel and alumina layer and clean-up, and fractionations, followed by Hypercarb-HPLC and PYE-HPLC sub-fractionation steps. Contents of 117 chlorobiphenyls determined in pine needles varied for the 25 sites studied and is between 2.7 and 49 ng/g wet weight. The PCBs pollution and congener-specific composition of pine needles to some degree varied according to the site or region surveyed depending on population density and industrialization. Many of the country-side areas showed lower concentrations between 2.7 and 8.9 ng/g ww. Pine needles in areas close to well populated and industrial regions of Opole, Kutno, Włocławek and Dębica showed the highest PCB pollution with concentrations varying between 30 and 49 ng/g ww. The Kutno site showed the highest pollution and this fact probably can be explained by possible emission from transformer manufactures located at some distance west of the Kutno area. Factor analysis (FA) and depending on the site revealed on relationship of PCBs composition of pine needles both with highly chlorinated PCB constituents of the mixtures such as Chlorofen, Aroclor 1254, Aroclor 1268 and Sovol but also of lower chlorinated PCB constituents of Aroclor 1242, Aroclor 1248, Clophen A40 or Delor 103. Thermal processes were considered a less significant source of PCBs in ambient air over Poland compared to evaporative sources related to technical PCB formulations. Supplemental materials are available for this article. Go to the publisher's online edition of Journal of

  19. The Growing Impact of Bioorthogonal Click Chemistry on the Development of Radiopharmaceuticals

    OpenAIRE

    Zeng, Dexing; Zeglis, Brian M; Lewis, Jason S.; Anderson, Carolyn J.

    2013-01-01

    Click chemistry has become a ubiquitous chemical tool with applications in nearly all areas of modern chemistry, including drug discovery, bioconjugation, and nanoscience. Radiochemistry is no exception, as the canonical Cu(I)-catalyzed azide-alkyne cycloaddition, strain-promoted azide-alkyne cycloaddition, inverse electron demand Diels-Alder reaction, and other types of bioorthogonal click ligations have had a significant impact on the synthesis and development of radiopharmaceuticals. This ...

  20. Click chemistry modification of surface-bound peptides towards applications in printable electronics

    OpenAIRE

    Schlageter, Martin

    2015-01-01

    This thesis shows the development of a method for the modification of surface-bound peptides. Initial attempts to functionalize amino acids with ferrocene derivatives led to a post-synthetic click grafting strategy, which could be shown to be feasible. This approach was extended to a two-step consecutive click sequence. Additionally, the grafting of Coordination clusters with the described method was investigated.

  1. Click-words: learning to predict document keywords from a user perspective

    OpenAIRE

    Islamaj Doğan, Rezarta; Lu, Zhiyong

    2010-01-01

    Motivation: Recognizing words that are key to a document is important for ranking relevant scientific documents. Traditionally, important words in a document are either nominated subjectively by authors and indexers or selected objectively by some statistical measures. As an alternative, we propose to use documents' words popularity in user queries to identify click-words, a set of prominent words from the users' perspective. Although they often overlap, click-words differ significantly from ...

  2. Real time classification of sperm whale clicks and shipping impulses from fixed ocean observatories

    OpenAIRE

    Zaugg, Serge Alain; Schaar, Mike van der; Houegnigan, Ludwig; André, Michel

    2010-01-01

    The automated acoustic detection of cetaceans in real time is an important tool to study their behaviour and distribution and for activating mitigation measures in the context of harmful anthropogenic activities at sea. Acoustic data from the NEMO ONDE deep sea observatory (Sicily) indicated that sperm whale clicks were present in 15 % of the recordings and impulsive ship noise in 10 %. The ship noise poses a serious challenge to the detection of sperm whale clicks, since it is...

  3. Sperm whale behaviour indicates the use of echolocation click buzzes "creaks" in prey capture.

    OpenAIRE

    Miller, Patrick J. O.; Johnson, Mark P.; Tyack, Peter L

    2004-01-01

    During foraging dives, sperm whales (Physeter macrocephalus) produce long series of regular clicks at 0.5-2 s intervals interspersed with rapid-click buzzes called "creaks". Sound, depth and orientation recording Dtags were attached to 23 whales in the Ligurian Sea and Gulf of Mexico to test whether the behaviour of diving sperm whales supports the hypothesis that creaks are produced during prey capture. Sperm whales spent most of their bottom time within one or two depth bands, apparently fe...

  4. Preliminary analysis on the tectonic stress level in the source region of Tangshan earthquake

    Institute of Scientific and Technical Information of China (English)

    赵建涛; 崔效锋; 谢富仁

    2002-01-01

    The abundant data of focal mechanism solutions in Tangshan region, China, are inverted for the tectonic stress field. Combined with tectonophysical consideration, the magnitude of the three principal stresses, as well as their vertical variation under the average crustal rock property, in the source region of the 1976 Tangshan earthquake is estimated. The relationship between crustal stress and friction (c, pore pressure P0 and stress shape factor ( is studied. The paper draws the conclusion that the vertical increasing rate of the maximum principal stress ( is directly proportional to friction, and inversely to pore pressure P0 and stress shape factor ( ; while the vertical increasing rate of the minimum principal tress ( is directly proportional to pore pressure P0, inversely to friction (c and stress shape factor (. This study is a try to invert the data of focal mechanism solutions for the complete stress tensor.

  5. EXPERIENCES FROM THE SOURCE-TERM ANALYSIS OF A LOW AND INTERMEDIATE LEVEL RADWASTE DISPOSAL FACILITY

    Energy Technology Data Exchange (ETDEWEB)

    Park,Jin Beak; Park, Joo-Wan; Lee, Eun-Young; Kim, Chang-Lak

    2003-02-27

    Enhancement of a computer code SAGE for evaluation of the Korean concept for a LILW waste disposal facility is discussed. Several features of source term analysis are embedded into SAGE to analyze: (1) effects of degradation mode of an engineered barrier, (2) effects of dispersion phenomena in the unsaturated zone and (3) effects of time dependent sorption coefficient in the unsaturated zone. IAEA's Vault Safety Case (VSC) approach is used to demonstrate the ability of this assessment code. Results of MASCOT are used for comparison purposes. These enhancements of the safety assessment code, SAGE, can contribute to realistic evaluation of the Korean concept of the LILW disposal project in the near future.

  6. Use of a parametric source term estimating code in level 2/3 PSAs

    International Nuclear Information System (INIS)

    Use of the XSOR methodology for establishing fission releases, provides a convenient and simple means of evaluating source terms, allowing for rapid evaluations of a large number of release classes. It offers a simple means of addressing core melt phenomenology and plant defense strategies that are not modeled in codes like MAAP and MELCOR and for accounting for and quantifying phenomenological uncertainties without relying on large number of complex deterministic analyses. This paper describes the application of the XSOR methodology to both BWR and PWR plants, the improvements to the US Reactor Risk Study XSOR models made by ABB, and compares the results of representative XSOR analyses with a similar uncertainty analysis of a MAAP 3.0B simulation

  7. Sources of variation in baseline gene expression levels from toxicogenomics study control animals across multiple laboratories

    Directory of Open Access Journals (Sweden)

    Lee Janice S

    2008-06-01

    Full Text Available Abstract Background The use of gene expression profiling in both clinical and laboratory settings would be enhanced by better characterization of variance due to individual, environmental, and technical factors. Meta-analysis of microarray data from untreated or vehicle-treated animals within the control arm of toxicogenomics studies could yield useful information on baseline fluctuations in gene expression, although control animal data has not been available on a scale and in a form best served for data-mining. Results A dataset of control animal microarray expression data was assembled by a working group of the Health and Environmental Sciences Institute's Technical Committee on the Application of Genomics in Mechanism Based Risk Assessment in order to provide a public resource for assessments of variability in baseline gene expression. Data from over 500 Affymetrix microarrays from control rat liver and kidney were collected from 16 different institutions. Thirty-five biological and technical factors were obtained for each animal, describing a wide range of study characteristics, and a subset were evaluated in detail for their contribution to total variability using multivariate statistical and graphical techniques. Conclusion The study factors that emerged as key sources of variability included gender, organ section, strain, and fasting state. These and other study factors were identified as key descriptors that should be included in the minimal information about a toxicogenomics study needed for interpretation of results by an independent source. Genes that are the most and least variable, gender-selective, or altered by fasting were also identified and functionally categorized. Better characterization of gene expression variability in control animals will aid in the design of toxicogenomics studies and in the interpretation of their results.

  8. A Low-Tech, Low-Budget Storage Solution for High Level Radioactive Sources

    Energy Technology Data Exchange (ETDEWEB)

    Brett Carlsen; Ted Reed; Todd Johnson; John Weathersby; Joe Alexander; Dave Griffith; Douglas Hamelin

    2014-07-01

    The need for safe, secure, and economical storage of radioactive material becomes increasingly important as beneficial uses of radioactive material expand (increases inventory), as political instability rises (increases threat), and as final disposal and treatment facilities are delayed (increases inventory and storage duration). Several vendor-produced storage casks are available for this purpose but are often costly — due to the required design, analyses, and licensing costs. Thus the relatively high costs of currently accepted storage solutions may inhibit substantial improvements in safety and security that might otherwise be achieved. This is particularly true in areas of the world where the economic and/or the regulatory infrastructure may not provide the means and/or the justification for such an expense. This paper considers a relatively low-cost, low-technology radioactive material storage solution. The basic concept consists of a simple shielded storage container that can be fabricated locally using a steel pipe and a corrugated steel culvert as forms enclosing a concrete annulus. Benefits of such a system include 1) a low-tech solution that utilizes materials and skills available virtually anywhere in the world, 2) a readily scalable design that easily adapts to specific needs such as the geometry and radioactivity of the source term material), 3) flexible placement allows for free-standing above-ground or in-ground (i.e., below grade or bermed) installation, 4) the ability for future relocation without direct handling of sources, and 5) a long operational lifetime . ‘Le mieux est l’ennemi du bien’ (translated: The best is the enemy of good) applies to the management of radioactive materials – particularly where the economic and/or regulatory justification for additional investment is lacking. Development of a low-cost alternative that considerably enhances safety and security may lead to a greater overall risk reduction than insisting on

  9. EFFECT OF ZINC SOURCE AND SUPPLEMENTATION LEVEL ON PRODUCTIVE INDICES IN BROILER CHICKENS

    Directory of Open Access Journals (Sweden)

    C. JULEAN

    2013-12-01

    Full Text Available In this experiment we have studied the effect of zinc provided from concentrated chelated glasses and inorganic substance (ZnO on nutritive and bioproductive indices in broiler chickens. The experiment was carried out on 120 broiler chickens divided into four experimental groups (CL, EL1, EL2 and EL3, with 30 broiler chickens in each experimental lot. The used hybrid was Ross 308. Zinc was provided by concentrated phosphatic glass with zinc (G 300 at following levels: at CL, 20 mg Zn, at EL1, 10 mg Zn, at EL2 40 mg Zn. At EL3 20 mg Zn was provided by inorganic substance (Zn O. Zinc assurance by G 300, at 20 mg/kg combined feed, determined superior bioproductive indices comparative with zinc assurance by Zn O at the same level.

  10. Source-Coupled, N-Channel, JFET-Based Digital Logic Gate Structure Using Resistive Level Shifters

    Science.gov (United States)

    Krasowski, Michael J.

    2011-01-01

    A circuit topography is used to create usable, digital logic gates using N (negatively doped) channel junction field effect transistors (JFETs), load resistors, level shifting resistors, and supply rails whose values are based on the DC parametric distributions of these JFETs. This method has direct application to the current state-of-the-art in high-temperature (300 to 500 C and higher) silicon carbide (SiC) device production, and defines an adaptation to the logic gate described in U.S. Patent 7,688,117 in that, by removing the level shifter from the output of the gate structure described in the patent (and applying it to the input of the same gate), a source-coupled gate topography is created. This structure allows for the construction AND/OR (sum of products) arrays that use far fewer transistors and resistors than the same array as constructed from the gates described in the aforementioned patent. This plays a central role when large multiplexer constructs are necessary; for example, as in the construction of memory. This innovation moves the resistive level shifter from the output of the basic gate structure to the front as if the input is now configured as what would be the output of the preceding gate, wherein the output is the two level shifting resistors. The output of this innovation can now be realized as the lone follower transistor with its source node as the gate output. Additionally, one may leave intact the resistive level shifter on the new gate topography. A source-coupled to direct-coupled logic translator will be the result.

  11. Sources of genetic resistance in maize to Fusarium stalk rot andtheir variations at molecular level

    OpenAIRE

    QURESHI, SAJJAD HUSSAIN; Qayyum, Abdul; FIERS, WILL

    2015-01-01

    Identifying the resistant genotypes is one of the vital strategies to control Fusarium stalk rot disease in maize. Fifty accessions of maize germplasm were evaluated for resistance to stalk rot caused by Fusarium verticillioides at the Maize and Millet Research Institute, Yousafwala, Pakistan, during the spring and autumn of 2010, and their genetic variations were also studied at the molecular level to avoid environmental effects in the Department of Medicinal Chemistry, University of Minneso...

  12. Sources of Continuity and Change in Activity Level in Early Childhood

    OpenAIRE

    Saudino, Kimberly J.

    2011-01-01

    Actigraphs and parent and observer ratings were used to explore genetic influences on continuity and change in activity level (AL) in early childhood. Over 300 pairs of twins wore actigraphs for a 48-hour period in the home and laboratory at ages 2 and 3. AL was genetically influenced at both ages with little evidence of differential heritability across age. For all measures, genetic influences contributed to phenotypic continuity. With the exception of the actigraph measure of AL in the home...

  13. Elevated Blood Lead Levels in Infants and Mothers in Benin and Potential Sources of Exposure

    OpenAIRE

    Florence Bodeau-Livinec; Philippe Glorennec; Michel Cot; Pierre Dumas; Séverine Durand; Achille Massougbodji; Pierre Ayotte; Barbara Le Bot

    2016-01-01

    Lead in childhood is well known to be associated with poor neurodevelopment. As part of a study on maternal anemia and offspring neurodevelopment, we analyzed blood lead level (BLL) with no prior knowledge of lead exposure in 225 mothers and 685 offspring 1 to 2 years old from Allada, a semi-rural area in Benin, sub-Saharan Africa, between May 2011 and May 2013. Blood samples were analyzed by inductively coupled plasma mass spectrometry. Environmental assessments in households and isotopic ra...

  14. DRINK: a biogeochemical source term model for low level radioactive waste disposal sites.

    Science.gov (United States)

    Humphreys, P; McGarry, R; Hoffmann, A; Binks, P

    1997-07-01

    Interactions between element chemistry and the ambient geochemistry play a significant role in the control of radionuclide migration in the geosphere. These same interactions influence radionuclide release from near surface, low level radioactive waste, disposal sites once physical containment has degraded. In situations where LLW contains significant amounts of metal and organic materials such as cellulose, microbial degradation in conjunction with corrosion can significantly perturb the ambient geochemistry. These processes typically produce a transition from oxidising to reducing conditions and can influence radionuclide migration through changes in both the dominant radionuclide species and mineral phases. The DRINK (DRIgg Near field Kinetic) code is a biogeochemical transport code designed to simulate the long term evolution of the UK low level radioactive waste disposal site at Drigg. Drigg is the UK's principal solid low level radioactive waste disposal site and has been receiving waste since 1959. The interaction between microbial activity, the ambient geochemistry and radionuclide chemistry is central to the DRINK approach with the development of the ambient pH, redox potential and bulk geochemistry being directly influenced by microbial activity. This paper describes the microbial aspects of the code, site data underpinning the microbial model, the microbiology/chemistry interface and provides an example of the code in action. PMID:9340003

  15. Learning to rank using user clicks and visual features for image retrieval.

    Science.gov (United States)

    Yu, Jun; Tao, Dacheng; Wang, Meng; Rui, Yong

    2015-04-01

    The inconsistency between textual features and visual contents can cause poor image search results. To solve this problem, click features, which are more reliable than textual information in justifying the relevance between a query and clicked images, are adopted in image ranking model. However, the existing ranking model cannot integrate visual features, which are efficient in refining the click-based search results. In this paper, we propose a novel ranking model based on the learning to rank framework. Visual features and click features are simultaneously utilized to obtain the ranking model. Specifically, the proposed approach is based on large margin structured output learning and the visual consistency is integrated with the click features through a hypergraph regularizer term. In accordance with the fast alternating linearization method, we design a novel algorithm to optimize the objective function. This algorithm alternately minimizes two different approximations of the original objective function by keeping one function unchanged and linearizing the other. We conduct experiments on a large-scale dataset collected from the Microsoft Bing image search engine, and the results demonstrate that the proposed learning to rank models based on visual features and user clicks outperforms state-of-the-art algorithms. PMID:25095275

  16. Multifaceted and route-controlled "click" reactions based on vapor-deposited coatings.

    Science.gov (United States)

    Sun, Ting-Pi; Tai, Ching-Heng; Wu, Jyun-Ting; Wu, Chih-Yu; Liang, Wei-Chieh; Chen, Hsien-Yeh

    2016-01-26

    "Click" reactions provide precise and reliable chemical transformations for the preparation of functional architectures for biomaterials and biointerfaces. The emergence of a multiple-click reaction strategy has paved the way for a multifunctional microenvironment with orthogonality and precise multitasking that mimics nature. We demonstrate a multifaceted and route-controlled click interface using vapor-deposited functionalized poly-para-xylylenes. Distinctly clickable moieties of ethynyl and maleimide were introduced into poly-para-xylylenes in one step via a chemical vapor deposition (CVD) copolymerization process. The advanced interface coating allows for a double-click route with concurrent copper(i)-catalyzed Huisgen 1,3-dipolar cycloaddition (CuAAC) and the thiol-maleimide click reaction. Additionally, double-click reactions can also be performed in a cascade manner by controlling the initiation route to enable the CuAAC and/or thiol-yne reaction using a mono-functional alkyne-functionalized poly-para-xylylene. The use of multifaceted coatings to create straightforward and orthogonal interface properties with respect to protein adsorption and cell attachment is demonstrated and characterized. PMID:26650976

  17. Interrelationships between intranarial pressure and biosonar clicks in the bottlenose dolphin (Tursiops truncatus)

    Science.gov (United States)

    Elsberry, Wesley R.; Cranford, Ted W.; Ridgway, Sam H.; Carder, Donald A.; Vanbonn, William G.; Blackwood, Diane J.; Carr, Jennifer A.; Evans, William E.

    2002-05-01

    Three Atlantic bottlenose dolphins (Tursiops truncatus) were given a target recognition biosonar task. During their performance of the task, both acoustic data in the far field and pressure within the bony nasal passages were digitally recorded (Elsberry et al., 1999). Analysis of over 15000 biosonar clicks provided new insights into odontocete biosonar sound production and is consistent with acoustic and pressure data taken from white whales (Delphinapterus leucas) during biosonar (Ridgway and Carder, 1988). Our work provides the first evidence for a minimum intranarial pressure during biosonar click production for any odontocete (11.8+/-0.5 kPascals over basal pressure). All three subjects exhibited nearly the same minimum tranarial pressure difference during biosonar click production. Clicks produced at or near this minimum intranarial pressure exhibited a wide range of acoustic power values. The acoustic power of a biosonar click was not highly correlated with intranarial pressure (R2=0.116). The radiated acoustic energy in biosonar clicks ranged from 1 to 1370 microJoules. Estimates of mechanical work during pressurization events were produced using a piston/cylinder model and intranarial volume data from prepared specimens and computed tomography scans. Mechanical work during pressurization events ranged from 2.74 to 23.0 Joules, with an average of 10.3 Joules.

  18. Concentration levels and source apportionment of ultrafine particles in road microenvironments

    Science.gov (United States)

    Argyropoulos, G.; Samara, C.; Voutsa, D.; Kouras, A.; Manoli, E.; Voliotis, A.; Tsakis, A.; Chasapidis, L.; Konstandopoulos, A.; Eleftheriadis, K.

    2016-03-01

    A mobile laboratory unit (MOBILAB) with on-board instrumentation (Scanning Mobility Particle Sizer, SMPS; Ambient NOx analyzer) was used to measure size-resolved particle number concentrations (PNCs) of quasi-ultrafine particles (UFPs, 9-372 nm), along with NOx, in road microenvironments. On-road measurements were carried out in and around a large Greek urban agglomeration, the Thessaloniki Metropolitan Area (TMA). Two 2-week measurement campaigns were conducted during the warm period of 2011 and the cold period of 2012. During each sampling campaign, MOBILAB was driven through a 5-day inner-city route and a second 5-day external route covering in total a wide range of districts (urban, urban background, industrial and residential), and road types (major and minor urban roads, freeways, arterial and interurban roads). All routes were conducted during working days, in morning and in afternoon hours under real-world traffic conditions. Spatial classification of MOBILAB measurements involved the assignment of measurement points to location bins defined by the aspect ratio of adjacent urban street canyons (USCs). Source apportionment was further carried out, by applying Positive Matrix Factorization (PMF) to particle size distribution data. Apportioned PMF factors were interpreted, by employing a two-step methodology, which involved (a) statistical association of PMF factor contributions with 12 h air-mass back-trajectories ending at the TMA during MOBILAB measurements, and (b) Multiple Linear Regression (MLR) using PMF factor contributions as the dependent variables, while relative humidity, solar radiation flux, and vehicle speed were used as the independent variables. The applied data analysis showed that low-speed cruise and high-load engine operation modes are the two dominant sources of UFPs in most of the road microenvironments in the TMA, with significant contributions from background photochemical processes during the warm period, explaining the reversed

  19. Effect of Different Sources and Levels of Zinc on Egg Quality and Laying Hen Performance

    OpenAIRE

    M.M. Tabatabaie; H. Aliarabi; A.A. Saki; Ahmadi, A. (Amir); S.A. Hosseini Siyar

    2007-01-01

    Eighty layer hens were assigned in a completely randomized design to four dietary treatments containing zinc sulphate or organic zinc as Albino-Zn in two levels of 25 or 50 ppm. Feed intake was expressed on a per hen basis. Daily egg collection was expressed on a hen-day basis. Eggs were weighed to calculate egg mass. Feed conversion ratio was calculated as feed consumed per egg mass. Also all eggs produced on days 14, 28 and 42 were collected and used for egg quality parameters. Albumen heig...

  20. The range and level of impurities in CO2 streams from different carbon capture sources

    OpenAIRE

    Porter, RTJ; Fairweather, M.; Pourkashanian, M.; Woolley, RM

    2015-01-01

    For CO2 capture and storage deployment, the impact of impurities in the gas or dense phase CO2 stream arising from fossil fuel power plants, or large scale industrial emitters, is of fundamental importance to the safe and economic transportation and storage of the captured CO2. This paper reviews the range and level of impurities expected from the main capture technologies used with fossil-fuelled power plants in addition to other CO2 emission-intensive industries. Analysis is presented with ...

  1. Plutonium, americium and other actinides on Belarus territory: source, levels, risks

    International Nuclear Information System (INIS)

    For Belarus it was showed that in result of falling during nuclear trials happened contamination of upper soil layer by transuranium elements with medium level of contamination for 239,240Pu 53±17 Bq/m2. After Chernobyl accident this characteristic equal 1.1· Bq/m2 on the south of Belarus. In result accident it was revealed 17 actinides. For Chernobyl falling was determined big contents of 241Pu that will lead to maximum value of 241Am in 2059, which will be more in 2,5 times than 239,240Pu

  2. Modelling street level PM10 concentrations across Europe: source apportionment and possible futures

    Directory of Open Access Journals (Sweden)

    G. Kiesewetter

    2014-07-01

    Full Text Available Despite increasing emission controls, particulate matter (PM has remained a critical issue for European air quality in recent years. The various sources of PM, both from primary particulate emissions as well as secondary formation from precursor gases, make this a complex problem to tackle. In order to allow for credible predictions of future concentrations under policy assumptions, a modelling approach is needed that considers all chemical processes and spatial dimensions involved, from long-range transport of pollution to local emissions in street canyons. Here we describe a modelling scheme which has been implemented in the GAINS integrated assessment model to assess compliance with PM10 (PM with aerodynamic diameter 10 across Europe. Furthermore, we analyse the predicted evolution of PM10 concentrations in the European Union until 2030 under different policy scenarios. Significant improvements in ambient PM10 concentrations are expected assuming successful implementation of already agreed legislation; however, these will not be large enough to ensure attainment of PM10 limit values in hot spot locations such as Southern Poland and major European cities. Remaining issues are largely eliminated in a scenario applying the best available emission control technologies to the maximal technically feasible extent.

  3. Elevated Blood Lead Levels in Infants and Mothers in Benin and Potential Sources of Exposure.

    Science.gov (United States)

    Bodeau-Livinec, Florence; Glorennec, Philippe; Cot, Michel; Dumas, Pierre; Durand, Séverine; Massougbodji, Achille; Ayotte, Pierre; Le Bot, Barbara

    2016-01-01

    Lead in childhood is well known to be associated with poor neurodevelopment. As part of a study on maternal anemia and offspring neurodevelopment, we analyzed blood lead level (BLL) with no prior knowledge of lead exposure in 225 mothers and 685 offspring 1 to 2 years old from Allada, a semi-rural area in Benin, sub-Saharan Africa, between May 2011 and May 2013. Blood samples were analyzed by inductively coupled plasma mass spectrometry. Environmental assessments in households and isotopic ratio measurements were performed for eight children with BLL > 100 µg/L. High lead levels (BLL > 50 µg/L) were found in 44% of mothers and 58% of children. The median BLL was 55.1 (interquartile range 39.2-85.0) and 46.6 (36.5-60.1) µg/L, respectively. Maternal BLL was associated with offspring's consumption of piped water and animals killed by ammunition. Children's BLL was associated with presence of paint chips in the house and consumption of animals killed by ammunition. In this population, with 98% of children still breastfed, children's BLL was highly associated with maternal BLL on multivariate analyses. Environmental measures and isotopic ratios supported these findings. Offspring may be highly exposed to lead in utero and probably via breastfeeding in addition to lead paint exposure. PMID:26978384

  4. Elevated Blood Lead Levels in Infants and Mothers in Benin and Potential Sources of Exposure

    Directory of Open Access Journals (Sweden)

    Florence Bodeau-Livinec

    2016-03-01

    Full Text Available Lead in childhood is well known to be associated with poor neurodevelopment. As part of a study on maternal anemia and offspring neurodevelopment, we analyzed blood lead level (BLL with no prior knowledge of lead exposure in 225 mothers and 685 offspring 1 to 2 years old from Allada, a semi-rural area in Benin, sub-Saharan Africa, between May 2011 and May 2013. Blood samples were analyzed by inductively coupled plasma mass spectrometry. Environmental assessments in households and isotopic ratio measurements were performed for eight children with BLL > 100 µg/L. High lead levels (BLL > 50 µg/L were found in 44% of mothers and 58% of children. The median BLL was 55.1 (interquartile range 39.2–85.0 and 46.6 (36.5–60.1 µg/L, respectively. Maternal BLL was associated with offspring’s consumption of piped water and animals killed by ammunition. Children’s BLL was associated with presence of paint chips in the house and consumption of animals killed by ammunition. In this population, with 98% of children still breastfed, children’s BLL was highly associated with maternal BLL on multivariate analyses. Environmental measures and isotopic ratios supported these findings. Offspring may be highly exposed to lead in utero and probably via breastfeeding in addition to lead paint exposure.

  5. Effects of dietary nitrogen levels and carbohydrate sources on apparent ruminal synthesis of some B vitamins in dairy cows.

    Science.gov (United States)

    Beaudet, V; Gervais, R; Graulet, B; Nozière, P; Doreau, M; Fanchone, A; Castagnino, D D S; Girard, C L

    2016-04-01

    Effects of nitrogen level and carbohydrate source on apparent ruminal synthesis (ARS) of thiamin, riboflavin, niacin, vitamin B6, folates, and vitamin B12 were evaluated using 4 lactating Holstein cows distributed in a 4 × 4 Latin square design with treatments following a 2 × 2 factorial arrangement. Cows were fitted with cannulas in the rumen and proximal duodenum. The treatments were 2 N levels and 2 carbohydrate sources. The diet with the high N level provided 14% crude protein, calculated to meet 110% of the protein requirements and an adequate supply in rumen-degradable protein, whereas the diet with the low N level contained 11% crude protein, calculated to meet 80% of the protein requirements with a shortage in rumen-degradable protein. Carbohydrate source treatments differed by their nature (i.e., high in starch from barley, corn, and wheat, or high in fiber from soybean hulls and dehydrated beet pulp). All 4 diets were isoenergetic, based on corn silage, and had the same forage-to-concentrate ratio (60:40, dry matter basis). Duodenal flow was determined using YbCl3 as a marker. Each B-vitamin ARS was calculated as duodenal flow minus daily intake. The intake of several B vitamins varied among treatments, but because the animals consumed a similar amount of feed every day (average of 20 kg of dry matter/d) the difference was mostly due to vitamin content of each ingredient and their relative proportion in the diets. Decreasing N concentration in the diet reduced vitamin B6 duodenal flow and increased its apparent ruminal degradation. It also decreased duodenal flow and ARS of folates. The high-starch diets increased duodenal flow and ruminal balance of riboflavin, vitamin B6, and folates, whereas the high-fiber diets increased vitamin B12 ARS and duodenal flow. These effects on apparent synthesis are possibly due to changes in ruminal fermentation. PMID:26851844

  6. Preindustrial atmospheric ethane levels inferred from polar ice cores: A constraint on the geologic sources of atmospheric ethane and methane

    Science.gov (United States)

    Nicewonger, Melinda R.; Verhulst, Kristal R.; Aydin, Murat; Saltzman, Eric S.

    2016-01-01

    Ethane levels were measured in air extracted from Greenland and Antarctic ice cores ranging in age from 994 to 1918 Common Era (C.E.) There is good temporal overlap between the two data sets from 1600 to 1750 C.E. with ethane levels stable at 397 ± 28 parts per trillion (ppt) (±2 standard error (s.e.)) over Greenland and 103 ± 9 ppt over Antarctica. The observed north/south interpolar ratio of ethane (3.9 ± 0.1, 1σ) implies considerably more ethane emissions in the Northern Hemisphere than in the Southern Hemisphere, suggesting geologic ethane sources contribute significantly to the preindustrial ethane budget. Box model simulations based on these data constrain the global geologic emissions of ethane to 2.2-3.5 Tg yr-1 and biomass burning emissions to 1.2-2.5 Tg yr-1 during the preindustrial era. The results suggest biomass burning emissions likely increased since the preindustrial period. Biomass burning and geologic outgassing are also sources of atmospheric methane. The results place constraints on preindustrial methane emissions from these sources.

  7. SYNMAG Photometry: A Fast Tool for Catalog-Level Matched Colors of Extended Sources

    CERN Document Server

    Bundy, Kevin; Higgs, Tim D; Nichol, Robert C; Yasuda, Naoki; Masters, Karen L; Lang, Dustin; Wake, David A

    2013-01-01

    Obtaining reliable, matched photometry for galaxies imaged by different observatories represents a key challenge in the era of wide-field surveys spanning more than several hundred square degrees. Methods such as flux fitting, profile fitting, and PSF homogenization followed by matched-aperture photometry are all computationally expensive. We present an alternative solution called "synthetic aperture photometry" that exploits galaxy profile fits in one band to efficiently model the observed, PSF-convolved light profile in other bands and predict the flux in arbitrarily sized apertures. Because aperture magnitudes are the most widely tabulated flux measurements in survey catalogs, producing synthetic aperture magnitudes (SYNMAGs) enables very fast matched photometry at the catalog level, without reprocessing imaging data. We make our code public and apply it to obtain matched photometry between SDSS ugriz and UKIDSS YJHK imaging, recovering red-sequence colors and photometric redshifts with a scatter and accur...

  8. IntentSearch: Capturing User Intention for One-Click Internet Image Search.

    Science.gov (United States)

    Tang, Xiaoou; Liu, Ke; Cui, Jingyu; Wen, Fang; Wang, Xiaogang

    2012-07-01

    Web-scale image search engines (e.g., Google image search, Bing image search) mostly rely on surrounding text features. It is difficult for them to interpret users' search intention only by query keywords and this leads to ambiguous and noisy search results which are far from satisfactory. It is important to use visual information in order to solve the ambiguity in text-based image retrieval. In this paper, we propose a novel Internet image search approach. It only requires the user to click on one query image with minimum effort and images from a pool retrieved by text-based search are reranked based on both visual and textual content. Our key contribution is to capture the users' search intention from this one-click query image in four steps. 1) The query image is categorized into one of the predefined adaptive weight categories which reflect users' search intention at a coarse level. Inside each category, a specific weight schema is used to combine visual features adaptive to this kind of image to better rerank the text-based search result. 2) Based on the visual content of the query image selected by the user and through image clustering, query keywords are expanded to capture user intention. 3) Expanded keywords are used to enlarge the image pool to contain more relevant images. 4) Expanded keywords are also used to expand the query image to multiple positive visual examples from which new query specific visual and textual similarity metrics are learned to further improve content-based image reranking. All these steps are automatic, without extra effort from the user. This is critically important for any commercial web-based image search engine, where the user interface has to be extremely simple. Besides this key contribution, a set of visual features which are both effective and efficient in Internet image search are designed. Experimental evaluation shows that our approach significantly improves the precision of top-ranked images and also the user

  9. A Self-Adaptive Dynamic Recognition Model for Fatigue Driving Based on Multi-Source Information and Two Levels of Fusion

    OpenAIRE

    Wei Sun; Xiaorui Zhang; Srinivas Peeta; Xiaozheng He; Yongfu Li; Senlai Zhu

    2015-01-01

    To improve the effectiveness and robustness of fatigue driving recognition, a self-adaptive dynamic recognition model is proposed that incorporates information from multiple sources and involves two sequential levels of fusion, constructed at the feature level and the decision level. Compared with existing models, the proposed model introduces a dynamic basic probability assignment (BPA) to the decision-level fusion such that the weight of each feature source can change dynamically with the ...

  10. Source identification and budget analysis on elevated levels of formaldehyde within ship plumes: a photochemical/dynamic model analysis

    Directory of Open Access Journals (Sweden)

    C. H. Song

    2010-06-01

    Full Text Available Elevated levels of formaldehyde (HCHO along the ship corridors have been observed by satellite sensors, such as ESA/ERS-2 GOME (Global Ozone Monitoring Experiment, and were also predicted by global 3-D chemistry-transport models. In this study, three likely sources of the elevated HCHO levels were investigated to identify the detailed sources and examine the contributions of the sources (budget of the elevated levels of HCHO in the ship corridors using a newly-developed ship-plume photochemical/dynamic model: (1 primary HCHO emission from ships; (2 secondary HCHO production via the atmospheric oxidation of Non-methane volatile organic compounds (NMVOCs emitted from ships; and (3 atmospheric oxidation of CH4 within the ship plumes. From multiple ship-plume model simulations, CH4 oxidation by elevated levels of in-plume OH radicals was found to be the main factor responsible for the elevated levels of HCHO in the ship corridors. More than ~91% of the HCHO for the base ship plume case (ITCT 2K2 ship-plume case is produced by this atmospheric chemical process, except in the areas close to the ship stacks where the main source of the elevated HCHO levels would be primary HCHO from the ships (due to the deactivation of CH4 oxidation from the depletion of in-plume OH radicals. Because of active CH4 oxidation (chemical destruction of CH4 by OH radicals, the instantaneous chemical lifetime of CH4 (τ CH4 decreased to ~0.45 yr inside the ship plume, which is in contrast to τ CH4 of ~1.1 yr in the background (up to ~41% decrease. A variety of likely ship-plume situations at three locations at different latitudes within the global ship corridors was also studied to determine the extent of the enhancements in the HCHOlevels in the marine boundary layer (MBL influenced by ship emissions. It was found that the ship-plume HCHO levels could be 20.5–434.9 pptv

  11. Persistent organic pollutant levels and the importance of source proximity in Baltic and Svalbard breeding common eiders.

    Science.gov (United States)

    Fenstad, Anette A; Jenssen, Bjørn M; Gabrielsen, Kristin M; Öst, Markus; Jaatinen, Kim; Bustnes, Jan O; Hanssen, Sveinn A; Moe, Børge; Herzke, Dorte; Krøkje, Åse

    2016-06-01

    The distance to sources and the long-range transport potential of persistent organic pollutants (POPs) are important in understanding the impact of anthropogenic pollution on natural seabird populations. The present study documented blood concentrations of POPs in the Baltic Sea (Tvärminne, Finland) population of common eiders (Somateria mollissima) in 2009 and in 2011 and compared the concentrations with the presumably less exposed Arctic population in Svalbard (Kongsfjorden, Norway). The Baltic population had 26, 10, and 5 times greater concentrations of hexachlorocyclohexane, polychlorinated biphenyls, and p,p'-dichlorodiphenyldichloroethylene than the Svalbard population. Unexpectedly, concentrations of chlordanes were higher in Svalbard eiders, whereas concentrations of hexachlorobenzenes (HCBs) did not differ between the 2 populations. Although the similar HCB levels may partly be explained by the high transport potential of HCBs, unknown factors may have been more important than distance to sources and long-range transport potential for the chlordanes. One plausible explanation may be that the fasting-related redistribution of POPs from fat to blood was greater throughout the incubation in Arctic eiders, causing them to have higher blood levels of these POPs at the end of incubation. The blood concentrations of POPs in Baltic eiders were higher than documented in any other eider population and were comparable to levels in seabirds feeding at higher trophic positions in the food chain. Environ Toxicol Chem 2016;35:1526-1533. © 2015 SETAC. PMID:26553455

  12. Power Quality Improvement at Distribution Level for Grid Connected Renewable Energy Sources

    Directory of Open Access Journals (Sweden)

    S. Syed Ahmed

    2014-09-01

    Full Text Available The non-linear load current harmonics may result in voltage harmonics and can create a serious PQ problem in the power system network. Active power filters (APF are extensively used to compensate the load current harmonics and load unbalance at distribution level. This results in an additional hardware cost. However, in this project it has incorporated the features of APF in the conventional inverter interfacing renewable with the grid, without any additional hardware cost. Here, the main idea is the maximum utilization of inverter rating which is most of the time underutilized due to intermittent nature of RES. The grid-interfacing inverter can effectively be utilized to perform the four important functions they are to transfer active power harvested from the renewable resources (wind, solar, etc., load reactive power demand support, current harmonics compensation at PCC and current unbalance and neutral current compensation in case of 3-phase 4-wire system. Moreover, with adequate control of grid-interfacing inverter, all the four objectives can be accomplished either individually or simultaneously. The PQ constraints at the PCC can therefore be strictly maintained within the utility standards without additional hardware cost. With such a control, the combination of grid-interfacing inverter and the 3-phase 4-wire linear/non-linear unbalanced load at point of common coupling appears as balanced linear load to the grid. This new control concept is demonstrated with extensive MATLAB/Simulink simulation studies

  13. Results of interagency effort to determine carbon-14 source term in low-level radioactive waste

    International Nuclear Information System (INIS)

    A preliminary estimate of the risks from the shallow land disposal of low-level radioactive wastes by EPA in 1984-1985 indicated that Carbon-14 caused virtually all of the risk and that these risks were relatively high. Therefore, an informal interagency group, which included the US Department of Energy, US Geological Survey, US Nuclear Regulatory Commission, and US Environmental Protection Agency, formed in 1985 to obtain up-to-date information on the activity and chemical form of Carbon-14 in the different types of LLW and how Carbon-14 behaves after disposal. The EPA acted as a focal point for collating the information collected by all of the Agencies and will publish a report in Fall 1986 on the results of the Carbon-14 data collection effort. Of particular importance, the study showed that Carbon-14 activity in LLW was overestimated approximately 2000%. This paper summarizes results of the Carbon-14 data collection effort. 40 references, 1 figure, 3 tables

  14. Use of the Drawing-Writing Technique to Determine the Level of Knowledge of Pre-Service Teachers Regarding Renewable Energy Sources

    Science.gov (United States)

    Kara, Filiz

    2015-01-01

    The aim of this study was to determine the level of knowledge of pre-service science teachers in Turkey regarding the different types of renewable energy sources, the methods used for obtaining energy from these sources, and the areas of use for these energy sources. Within the context of the study, the drawing-writing technique was used in order…

  15. Click beetle luciferases as dual reporters of gene expression in Candida albicans.

    Science.gov (United States)

    Kapitan, Mario; Eichhof, Isabel; Lagadec, Quentin; Ernst, Joachim F

    2016-08-01

    Synthetic genes encoding functional luciferases of the click beetle (CB) Pyrophorus plagiophthalamus have been expressed in the human fungal pathogen Candida albicans. Both green- and red-emitting CB luciferases (CaCBGluc and CaCBRluc) were produced with high efficiency in transformants under transcriptional control of the growth-dependent ACT1 promoter, as well as by the HWP1 and UME6 promoters, which are upregulated during hyphal morphogenesis, as well as by the YWP1 and EFG1 promoters, which are downregulated. For all hyphally regulated genes, relative bioluminescence values derived from promoter fusions approximated relative transcript levels of native genes, although downregulation of YWP1 promoter activity required correction for the stability of CB luciferases (approximate half-lives 30 min for CaCBRluc and 80 min for CaCBGluc, as determined by immunoblotting). Importantly, the activity of both luciferases could be separately monitored in a single strain, in intact cells, in lysed cells or in cell extracts using luciferin as single substrate and inhibition of hypha formation by farnesol could be easily detected by the HWP1p-CaCBRluc fusion. The results suggest that CB luciferases are convenient tools to measure gene expression in C. albicans and may facilitate screenings for antifungal compounds. PMID:27339610

  16. Sources of variability in alpha emissivity measurements at LA and ULA levels, a multicenter study

    Energy Technology Data Exchange (ETDEWEB)

    McNally, Brendan D., E-mail: brendan@xia.com [XIA LLC, 31057 Genstar Rd., Hayward, CA 94544 (United States); Coleman, Stuart; Warburton, William K. [XIA LLC, 31057 Genstar Rd., Hayward, CA 94544 (United States); Autran, Jean-Luc [Aix-Marseille University and CNRS, Faculté des Sciences–Service 142, F-13397 Marseille Cedex 20 (France); Clark, Brett M. [Honeywell, 15128 E. Euclid Ave., Spokane, WA 99216 (United States); Cooley, Jodi [Southern Methodist University–Physics Department, Dallas, TX 75275 (United States); Gordon, Michael S. [IBM TJ Watson Research Center, 1101 Kitchawan Rd., Yorktown Heights, NY 10598 (United States); Zhu, Zhengmao [IBM SRDC, 2070 Rte 52, Bldg 300, 1W4-111, Hopewell Junction, NY 12533 (United States)

    2014-06-01

    Alpha emissivity measurements are important in the semiconductor industry for assessing the suitability of materials for use in production processes. A recently published round-robin study that circulated the same samples to several alpha counting centers showed wide center-to-center variations in measured alpha emissivity. A separate analysis of these results hypothesized that much of the variation might arise from differences in sample-to-entrance window separations. XIA recently introduced an ultra low background counter, the UltraLo-1800 (“UltraLo”), that operates in a fundamentally different manner from the proportional counters used at most of the centers in the original study. In particular, by placing the sample within the counting volume, it eliminates the sample-to-entrance window separation issue noted above, and so offers an opportunity to test this hypothesis. In this work we briefly review how the UltraLo operates and describe a new round-robin study conducted entirely on UltraLo instruments using a set of standard samples that included two samples used in the original study. This study shows that, for LA (“Low Alpha” between 2 and 50 α/khr-cm{sup 2}) sample measurements, the only remaining site-to-site variations were due to counting statistics. Variations in ULA (“Ultra-Low Alpha”<2 α/khr-cm{sup 2}) sample measurements were reduced three-fold, compared to the earlier study, with the measurements suggesting that residual activity variations now primarily arise from site-to-site differences in the cosmogenic background. - Highlights: • We sent a set of samples to 6 counting centers for alpha emissivity measurement. • The counting centers conducted measurements using a recently developed instrument. • The variability in measurement results is examined and compared to a prior study. • Minimal variability observed in measurements of LA level samples. • Variability in ULA measurements appears to be due to cosmogenic background.

  17. Sources of variability in alpha emissivity measurements at LA and ULA levels, a multicenter study

    International Nuclear Information System (INIS)

    Alpha emissivity measurements are important in the semiconductor industry for assessing the suitability of materials for use in production processes. A recently published round-robin study that circulated the same samples to several alpha counting centers showed wide center-to-center variations in measured alpha emissivity. A separate analysis of these results hypothesized that much of the variation might arise from differences in sample-to-entrance window separations. XIA recently introduced an ultra low background counter, the UltraLo-1800 (“UltraLo”), that operates in a fundamentally different manner from the proportional counters used at most of the centers in the original study. In particular, by placing the sample within the counting volume, it eliminates the sample-to-entrance window separation issue noted above, and so offers an opportunity to test this hypothesis. In this work we briefly review how the UltraLo operates and describe a new round-robin study conducted entirely on UltraLo instruments using a set of standard samples that included two samples used in the original study. This study shows that, for LA (“Low Alpha” between 2 and 50 α/khr-cm2) sample measurements, the only remaining site-to-site variations were due to counting statistics. Variations in ULA (“Ultra-Low Alpha”2) sample measurements were reduced three-fold, compared to the earlier study, with the measurements suggesting that residual activity variations now primarily arise from site-to-site differences in the cosmogenic background. - Highlights: • We sent a set of samples to 6 counting centers for alpha emissivity measurement. • The counting centers conducted measurements using a recently developed instrument. • The variability in measurement results is examined and compared to a prior study. • Minimal variability observed in measurements of LA level samples. • Variability in ULA measurements appears to be due to cosmogenic background

  18. Optimization of Extreme Ultraviolet Light Source from High Harmonic Generation for Condensed-Phase Core-Level Spectroscopy

    Science.gov (United States)

    Lin, Ming-Fu; Verkamp, Max A.; Ryland, Elizabeth S.; Benke, Kristin; Zhang, Kaili; Carlson, Michaela; Vura-Weis, Josh

    2015-06-01

    Extreme ultraviolet (XUV) light source from high-order harmonic generation has been shown to be a powerful tool for core-level spectroscopy. In addition, this light source provides very high temporal resolution (10-18 s to 10-15 s) for time-resolved transient absorption spectroscopy. Most applications of the light source have been limited to the studies of atomic and molecular systems, with technique development focused on optimizing for shorter pulses (i.e. tens of attoseconds) or higher XUV energy (i.e. ~keV range). For the application to general molecular systems in solid and liquid forms, however, the XUV photon flux and stability are highly demanded due to the strong absorption by substrates and solvents. In this case, the main limitation is due to the stability of the high order generation process and the limited bandwidth of the XUV source that gives only discrete even/odd order peaks. Consequently, this results in harmonic artifact noise that overlaps with the resonant signal. In our current study, we utilize a semi-infinite cell for high harmonic generation from two quantum trajectories (i.e. short and long) at over-driven NIR power. This condition, produces broad XUV spectrum without using complicated optics (e.g. hollow-core fibers and double optical gating). This light source allows us to measure the static absorption spectrum of the iron M-edge from a Fe(acac)3 molecular solid film, which shows a resonant feature of 0.01 OD (~2.3% absorption). Moreover, we also investigate how sample roughness affects the static absorption spectrum. We are able to make smooth solar cell precursor materials (i.e. PbI2 and PbBr2) by spin casting and observe iodine (50 eV) and bromine (70 eV) absorption edges in the order of 0.05 OD with minimal harmonic artifact noise.

  19. Unified System-Level Modeling of Intermittent Renewable Energy Sources and Energy Storage for Power System Operation

    DEFF Research Database (Denmark)

    Heussen, Kai; Koch, Stephan; Ulbig, Andreas;

    2011-01-01

    The system-level consideration of inter- mittent renewable energy sources and small-scale en- ergy storage in power systems remains a challenge as either type is incompatible with traditional operation concepts. Non-controllability and energy-constraints are still considered contingent cases in...... market-based operation. The design of operation strategies for up to 100 % renewable energy systems requires an explicit consideration of non-dispatchable generation and stor- age capacities, as well as the evaluation of operational performance in terms of energy eciency, reliability, environmental...... in power system operation. After introducing the modeling ap- proach, a case study is presented for illustration....

  20. Ultrasound responsive block copolymer micelle of poly(ethylene glycol)-poly(propylene glycol) obtained through click reaction.

    Science.gov (United States)

    Li, Fayong; Xie, Chuan; Cheng, Zhengang; Xia, Hesheng

    2016-05-01

    The well-defined amphiphilic poly(ethylene glycol)-block-poly(propylene glycol) copolymer containing 1, 2, 3-triazole moiety and multiple ester bonds (PEG-click-PPG) was prepared by click reaction strategy. The PEG-click-PPG copolymer can self-assemble into spherical micelles in aqueous solution. It is found that high intensity focused ultrasound (HIFU) can open the copolymer PEG-click-PPG micelles and trigger the release of the payload in the micelle. The multiple ester bonds introduced in the junction point of the copolymer chain through click reactions were cleaved under HIFU, and leads to the disruption of the copolymer micelle and fast release of loaded cargo. The click reaction provides a convenient way to construct ultrasound responsive copolymer micelles with weak bonds. PMID:26703197

  1. OSD: A Source Level Bug Localization Technique Incorporating Control Flow and State Information in Object Oriented Program

    CERN Document Server

    Ray, Partha Pratim

    2011-01-01

    Bug localization in object oriented program ha s always been an important issue in softeware engineering. In this paper, I propose a source level bug localization technique for object oriented embedded programs. My proposed technique, presents the idea of debugging an object oriented program in class level, incorporating the object state information into the Class Dependence Graph (ClDG). Given a program (having buggy statement) and an input that fails and others pass, my approach uses concrete as well as symbolic execution to synthesize the passing inputs that marginally from the failing input in their control flow behavior. A comparison of the execution traces of the failing input and the passing input provides necessary clues to the root-cause of the failure. A state trace difference, regarding the respective nodes of the ClDG is obtained, which leads to detect the bug in the program.

  2. Diffusion from a Ground Level Point Source Experiment with Thermoluminescence Dosimeters and Kr 85 as Tracer Substance

    International Nuclear Information System (INIS)

    Within the framework of the IRIS-project (Iodine Research in Safety Project) an experiment to study diffusion at near-ground level was carried out on 19 December 1967 using 85Kr as the tracer element. The object of the experiment was a) to test the method using |3-sensitive thermoluminescence dosimeters under actual field conditions. b) to study the initial dilution from a ground level point source. The test area chosen was the Tranvik valley just south of Trobbofjaerden, an inland bay of the Baltic. Dose distributions have been studied at two sections, 50 and 200 m respectively, from the release point. At each level various dispersion parameters have been experimentally determined and their conformity to normal distribution have been calculated. Dilution factors valid for the centre of the plume are related to the values reported in the literature. The experiment was made under ideal weather conditions above snow-free ground. Results of the next experiment, a point release at ground level from a building at Studsvik, are expected to yield valuable information concerning the effect of buildings on the diffusion pattern

  3. Effect of foliar application of different Fe levels and sources on growth and concentration of some nutrients in sorghum

    Directory of Open Access Journals (Sweden)

    L. Jokar

    2015-08-01

    Full Text Available One of the fast responding methods of plants to fertilizer application is foliar application, which saves fertilizer consumption too. Foliar application of micronutrients is a useful method, especially when roots are unable to absorb necessary elements from soil. The amount of available iron (Fe in calcareous soils, with high pH, is low for sensitive plants, such as sorghum, to Fe deficiency. To compare the effect of foliar application of different Fe sources on growth traits, concentration and uptake of nutrients in sorghum, a greenhouse experiment was conducted as a completely randomized design with three replications. Treatments consisted of three levels of Fe (0, 90 and 180 mg Fe/L from three sources of Fe (Fe nano-chelate, Fe-EDDHA and FeSO4.7H2O. Results showed that application of all three sources of Fe increased shoot and root dry matter yield, plant height, leaf chlorophyll content, shoot Fe concentration and uptake as compared to control treatment. Foliar application of Fe reduced concentrations of P and Mn in shoot, but had no significant effect on root P, Mn and Fe concentrations. Concentration of Zn and Cu in shoot and root of sorghum was not affected by level of Fe application. Based on the results of this experiment, foliar application of FeSO4.7H2O compared to Fe-EDDHA and Fe nano-chelate can increase growth and improve some characteristics of sorghum plants under greenhouse conditions. This result is economically affordable as well.

  4. Crosslinking of Kapok Cellulose Fiber via Azide Alkyne Click Chemistry as a New Material for Filtering System: A Preliminary Study

    Directory of Open Access Journals (Sweden)

    Nur Syazwani Abd Rahman

    2016-01-01

    Full Text Available A new class of green material has been elaborated by grafting the modified kapok fiber, by the means of azidated kapok fiber followed by “click-chemistry” reaction with the terminal alkyne crosslinker. The modified and synthesized product was characterized using Fourier transform infrared spectroscopy (FT-IR, and Scanning electron microscopy (SEM. The study also was undertaken to investigate the effect on the absorption of methylene blue from aqueous solution onto the click fiber prepared. The findings showed that the click kapok absorbed more compared to the untreated kapok. Based on the result, the reaction of click chemistry influenced the properties of the filter made from kapok fiber.

  5. Impact of external industrial sources on the regional and local SO2 and O3 levels of the Mexico megacity

    Science.gov (United States)

    Almanza, V. H.; Molina, L. T.; Li, G.; Fast, J.; Sosa, G.

    2014-08-01

    The air quality of megacities can be influenced by external emission sources on both global and regional scales. At the same time their outflow emissions can exert an impact to the surrounding environment. The present study evaluates an SO2 peak observed on 24 March 2006 at the suburban supersite T1 and at ambient air quality monitoring stations located in the northern region of the Mexico City Metropolitan Area (MCMA) during the Megacity Initiative: Local and Global Research Observations (MILAGRO) field campaign. We found that this peak could be related to an important episodic emission event coming from Tizayuca region, northeast of the MCMA. Back-trajectory analyses suggest that the emission event started in the early morning at 04:00 LST and lasted for about 9 h. The estimated emission rate is about 2 kg s-1. To the best of our knowledge, sulfur dioxide emissions from the Tizayuca region have not been considered in previous studies. This finding suggests the possibility of "overlooked" emission sources in this region that could influence the air quality of the MCMA. This further motivated us to study the cement plants, including those in the state of Hidalgo and in the State of Mexico. It was found that they can contribute to the SO2 levels in the northeast (NE) region of the basin (about 42%), at the suburban supersite T1 (41%) and that at some monitoring stations their contribution can be even higher than the contribution from the Tula Industrial Complex (TIC). The contribution of the Tula Industrial Complex to regional ozone levels is estimated. The model suggests low contribution to the MCMA (1 to 4 ppb) and slightly higher contribution at the suburban T1 (6 ppb) and rural T2 (5 ppb) supersites. However, the contribution could be as high as 10 ppb in the upper northwest region of the basin and in the southwest and south-southeast regions of the state of Hidalgo. In addition, the results indicated that the ozone plume could also be transported to northwest

  6. Sources of signal in 62 protein-coding nuclear genes for higher-level phylogenetics of arthropods.

    Directory of Open Access Journals (Sweden)

    Jerome C Regier

    Full Text Available BACKGROUND: This study aims to investigate the strength of various sources of phylogenetic information that led to recent seemingly robust conclusions about higher-level arthropod phylogeny and to assess the role of excluding or downweighting synonymous change for arriving at those conclusions. METHODOLOGY/PRINCIPAL FINDINGS: The current study analyzes DNA sequences from 68 gene segments of 62 distinct protein-coding nuclear genes for 80 species. Gene segments analyzed individually support numerous nodes recovered in combined-gene analyses, but few of the higher-level nodes of greatest current interest. However, neither is there support for conflicting alternatives to these higher-level nodes. Gene segments with higher rates of nonsynonymous change tend to be more informative overall, but those with lower rates tend to provide stronger support for deeper nodes. Higher-level nodes with bootstrap values in the 80% - 99% range for the complete data matrix are markedly more sensitive to substantial drops in their bootstrap percentages after character subsampling than those with 100% bootstrap, suggesting that these nodes are likely not to have been strongly supported with many fewer data than in the full matrix. Data set partitioning of total data by (mostly synonymous and (mostly nonsynonymous change improves overall node support, but the result remains much inferior to analysis of (unpartitioned nonsynonymous change alone. Clusters of genes with similar nonsynonymous rate properties (e.g., faster vs. slower show some distinct patterns of node support but few conflicts. Synonymous change is shown to contribute little, if any, phylogenetic signal to the support of higher-level nodes, but it does contribute nonphylogenetic signal, probably through its underlying heterogeneous nucleotide composition. Analysis of seemingly conservative indels does not prove useful. CONCLUSIONS: Generating a robust molecular higher-level phylogeny of Arthropoda is

  7. PM10 concentration levels at an urban and background site in Cyprus: the impact of urban sources and dust storms.

    Science.gov (United States)

    Achilleos, Souzana; Evans, John S; Yiallouros, Panayiotis K; Kleanthous, Savvas; Schwartz, Joel; Koutrakis, Petros

    2014-12-01

    Air quality in Cyprus is influenced by both local and transported pollution, including desert dust storms. We examined PM10 concentration data collected in Nicosia (urban representative) from April 1, 1993, through December 11, 2008, and in Ayia Marina (rural background representative) from January 1, 1999, through December 31, 2008. Measurements were conducted using a Tapered Element Oscillating Micro-balance (TEOM). PM10 concentrations, meteorological records, and satellite data were used to identify dust storm days. We investigated long-term trends using a Generalized Additive Model (GAM) after controlling for day of week, month, temperature, wind speed, and relative humidity. In Nicosia, annual PM10 concentrations ranged from 50.4 to 63.8 μg/m3 and exceeded the EU annual standard limit enacted in 2005 of 40 μg/m3 every year A large, statistically significant impact of urban sources (defined as the difference between urban and background levels) was seen in Nicosia over the period 2000-2008, and was highest during traffic hours, weekdays, cold months, and low wind conditions. Our estimate of the mean (standard error) contribution of urban sources to the daily ambient PM10 was 24.0 (0.4) μg/m3. The study of yearly trends showed that PM10 levels in Nicosia decreased from 59.4 μg/m3 in 1993 to 49.0 μg/m3 in 2008, probably in part as a result of traffic emission control policies in Cyprus. In Ayia Marina, annual concentrations ranged from 27.3 to 35.6 μg/m3, and no obvious time trends were observed. The levels measured at the Cyprus background site are comparable to background concentrations reported in other Eastern Mediterranean countries. Average daily PM10 concentrations during desert dust storms were around 100 μg/m3 since 2000 and much higher in earlier years. Despite the large impact ofdust storms and their increasing frequency over time, dust storms were responsible for a small fraction of the exceedances of the daily PM10 limit. Implications: This

  8. Regulation of glucose and lipid metabolism by dietary carbohydrate levels and lipid sources in gilthead sea bream juveniles.

    Science.gov (United States)

    Castro, Carolina; Corraze, Geneviève; Firmino-Diógenes, Alexandre; Larroquet, Laurence; Panserat, Stéphane; Oliva-Teles, Aires

    2016-07-01

    The long-term effects on growth performance, body composition, plasma metabolites, liver and intestine glucose and lipid metabolism were assessed in gilthead sea bream juveniles fed diets without carbohydrates (CH-) or carbohydrate-enriched (20 % gelatinised starch, CH+) combined with two lipid sources (fish oil; or vegetable oil (VO)). No differences in growth performance among treatments were observed. Carbohydrate intake was associated with increased hepatic transcripts of glucokinase but not of 6-phosphofructokinase. Expression of phosphoenolpyruvate carboxykinase was down-regulated by carbohydrate intake, whereas, unexpectedly, glucose 6-phosphatase was up-regulated. Lipogenic enzyme activities (glucose-6-phosphate dehydrogenase, malic enzyme, fatty acid synthase) and ∆6 fatty acyl desaturase (FADS2) transcripts were increased in liver of fish fed CH+ diets, supporting an enhanced potential for lipogenesis and long-chain PUFA (LC-PUFA) biosynthesis. Despite the lower hepatic cholesterol content in CH+ groups, no influence on the expression of genes related to cholesterol efflux (ATP-binding cassette G5) and biosynthesis (lanosterol 14 α-demethylase, cytochrome P450 51 cytochrome P450 51 (CYP51A1); 7-dehydrocholesterol reductase) was recorded at the hepatic level. At the intestinal level, however, induction of CYP51A1 transcripts by carbohydrate intake was recorded. Dietary VO led to decreased plasma phospholipid and cholesterol concentrations but not on the transcripts of proteins involved in phospholipid biosynthesis (glycerol-3-phosphate acyltransferase) and cholesterol metabolism at intestinal and hepatic levels. Hepatic and muscular fatty acid profiles reflected that of diets, despite the up-regulation of FADS2 transcripts. Overall, this study demonstrated that dietary carbohydrates mainly affected carbohydrate metabolism, lipogenesis and LC-PUFA biosynthesis, whereas effects of dietary lipid source were mostly related with tissue fatty acid composition

  9. Selected organochlorine pesticides in the atmosphere of major Indian cities: levels, regional versus local variations, and sources.

    Science.gov (United States)

    Chakraborty, Paromita; Zhang, Gan; Li, Jun; Xu, Yue; Liu, Xiang; Tanabe, Shinsuke; Jones, Kevin C

    2010-11-01

    India has extensive production and usage of organochlorine pesticides (OCPs) for agriculture and vector control. Despite this, few data are available on the levels and distribution of OCPs in the urban atmosphere of India. Passive and active air sampling was therefore conducted between Dec 2006 and March 2007 in 7 metropolitan cities: New Delhi, Kolkata, Mumbai, Chennai, Bangalore, Goa, and Agra. Concentrations (pg·m(-3)) were as follows: HCHs 890-17000 (mean: 5400 ± 4110); DDTs 250-6110 (1470 ± 1010); chlordanes 290-5260 (1530 ± 790); endosulfans 240-4650 (1040 ± 610); and hexachlorobenzene 120-2890 (790 ± 510). HCHs observed in India appear to be the highest reported across the globe. Chlordanes and endosulfans are lower than levels reported from southern China. Passive sampling enabled within- and between-city variations to be assessed. As expected, paired-sample t-test analysis revealed higher regional than local variation. Comparisons with the limited data available from studies conducted in 1989 suggest general declines of HCHs and DDTs for most regions. γ-HCH dominated the HCH signal, reflecting widespread use of Lindane in India, although the isomeric composition in Kolkata suggests potential technical HCH use. High o,p'-/p,p'-DDT ratios in northern India indicate recent DDT usage. High HCB levels in the industrial areas of New Delhi and Kolkata indicate ongoing sources. Correlation between trans- and cis-chlordane implies ongoing usage. Endosulfan sulfate generally dominated the endosulfan signal, but high values of α/β-endosulfan at Chennai, Mumbai and Goa suggest ongoing usage. Backward trajectories were computed using the NOAA HYSPLIT model to trace the air mass history. Result shows local/regional sources of OCPs within India. PMID:20879790

  10. Tracing dust sources in different atmosphere levels of Tehran using hybrid single-particle lagrangian integrated trajectory (HYSPLIT model

    Directory of Open Access Journals (Sweden)

    Fahimeh Mohammadi

    2014-07-01

    Full Text Available Thepresent study aims to tracing dust sources of Tehran (capital city of Iranusing HYSPLIT model and atmospheric circulationsystems atdifferent levels. The statistical analyses within the period 1981-2005 indicatethat one of the most significant dust events in Tehran province occurred in May2000 and continued for more than 4 days in Abali, Chitgar, Firuzkuh, Karaj andNorth Tehran stations. For this purpose, in order to identify the sources of dustparticles and their directions, firstly, high-level atmospheric data includingzonal and meridional wind, geopotential height at pressure levelof 700 and 850 hPa and atmospheric circulation patterns werestudied from two days before the storm, the first of May until the end of thesecond, fourth and fifth day. By using atmospheric circulation maps, the synoptic systems effective in causing dust events, flowsdirections and their speeds were determined. In this modeling approach, a backwardparticle tracking method was applied to determine the direction of dustparticles, 48 hours before dust storm in Tehran, at three elevations of 100,500 and 1000 meter. With regard to the fact that the pressure systems ofnorthern latitudes are active over Iran in transition period of spring, itshould be noted that the results of the present study were affected by thesesystems. Results indicate that the high-pressure system hovering above theSaudi Arabia and the low-pressure tongue at higher latitudes play an importantrole in forming particle motion patterns and flow speeds of mentioned levels.Using HYSPLIT Lagrangian model shows the effects of arid regions of SaudiArabia, Iraq and some parts of Syria on producing greatest amount of dustparticles transferred to Tehran.

  11. Impact of external industrial sources on the regional and local SO₂ and O₃ levels of the Mexico megacity

    Energy Technology Data Exchange (ETDEWEB)

    Almanza, V. H.; Molina, Luisa T.; Li, Guohui; Fast, Jerome D.; Sosa, G.

    2014-08-22

    The air quality of megacities can be influenced by external emissions sources on both global and regional scale, and at the same time their outflow emissions can exert an important impact to the surrounding environment. The present study evaluates an SO₂ peak observed on 24 March 2006 at the suburban supersite T1 and ambient air quality monitoring stations located in the north region of the Mexico City Metropolitan Area (MCMA) during MILAGRO campaign. We found that this peak could be related to an important episodic emission event from Tizayuca region, northeast of the MCMA. Back trajectories analyses suggest that the emission event started in the early morning at 10 04:00 LST and lasted for about 9 h. The estimated emission rate is noticeably high, about 2 kgs-¹. This finding suggests the possibility of "overlooked"emission sources in this region that could influence the air quality of the MCMA. This further motivated us to study the cement plants, including those in the State of Hidalgo and in the State of Mexico, and we found that they can contribute in the NE region of the basin (about 15 41.7%), at the suburban supersite T1 (41.23%) and at some monitoring stations their contribution can be even higher than from the Tula Industrial Complex. The contribution of Tula Industrial Complex to regional ozone levels is estimated. The model suggests low contribution to the MCMA (1 ppb to 4 ppb) and slightly higher at the suburban T1 (6 ppb) and rural T2 (5 ppb) supersites. However, the contribution could be 20 as high as 10 ppb in the upper northwest region of the basin and in the southwest and south-southeast regions of State of Hidalgo. In addition, a first estimate of the potential contribution from flaring activities to regional ozone levels is presented. Emission rates are estimated with a CFD combustion model. Results suggest that up to 30% of the total regional ozone from TIC could be related to flaring activities. 25 Finally, the influence in SO₂ levels

  12. Fluorine-18 labeling by click chemistry: Multiple probes in one pot

    International Nuclear Information System (INIS)

    Click chemistry has been widely applied in drug development including radiopharmaceuticals and has shown great advantages. Here we reported a novel strategy for rapid preparation of multiple 18F labeled PET probes in one pot using the ‘Click Reaction’ of Cu(I)-catalyzed Huisgen 1,3-dipolar cycloaddition of terminal alkynes and organic azides (CuAAC). Preliminary results showed its high efficiency and potential for speeding up the preclinical screening of PET probes. - Highlights: ► With click labeling method, multiple PET probes can be labeled in one pot with high efficiency. ► Under proper HPLC conditions, multiple probes can be separated with high radiochemical purities and chemical purities. ► This strategy if combined with high throughout screening, the discovery of PET probes may be accelerated

  13. Surface modification of nanoporous 1,2-polybutadiene by atom transfer radical polymerization or click chemistry.

    Science.gov (United States)

    Guo, Fengxiao; Jankova, Katja; Schulte, Lars; Vigild, Martin E; Ndoni, Sokol

    2010-02-01

    Surface-initiated atom transfer radical polymerization (ATRP) and click chemistry were used to obtain functional nanoporous polymers based on nanoporous 1,2-polybutadiene (PB) with gyroid morphology. The ATRP monolith initiator was prepared by immobilizing bromoester initiators onto the pore walls through two different methodologies: (1) three-step chemical conversion of double bonds of PB into bromoisobutyrate, and (2) photochemical functionalization of PB with bromoisobutyrate groups. Azide functional groups were attached onto the pore walls before click reaction with alkynated MPEG. Following ATRP-grafting of hydrophilic polyacrylates and click of MPEG, the originally hydrophobic samples transformed into hydrophilic nanoporous materials. The successful modification was confirmed by infrared spectroscopy, contact angle measurements and measurements of spontaneous water uptake, while the morphology was investigated by small-angle X-ray scattering and transmission electron microscopy. PMID:20099923

  14. A multi-source satellite data approach for modelling Lake Turkana water level: Calibration and validation using satellite altimetry data

    Science.gov (United States)

    Velpuri, N.M.; Senay, G.B.; Asante, K.O.

    2012-01-01

    Lake Turkana is one of the largest desert lakes in the world and is characterized by high degrees of interand intra-annual fluctuations. The hydrology and water balance of this lake have not been well understood due to its remote location and unavailability of reliable ground truth datasets. Managing surface water resources is a great challenge in areas where in-situ data are either limited or unavailable. In this study, multi-source satellite-driven data such as satellite-based rainfall estimates, modelled runoff, evapotranspiration, and a digital elevation dataset were used to model Lake Turkana water levels from 1998 to 2009. Due to the unavailability of reliable lake level data, an approach is presented to calibrate and validate the water balance model of Lake Turkana using a composite lake level product of TOPEX/Poseidon, Jason-1, and ENVISAT satellite altimetry data. Model validation results showed that the satellitedriven water balance model can satisfactorily capture the patterns and seasonal variations of the Lake Turkana water level fluctuations with a Pearson's correlation coefficient of 0.90 and a Nash-Sutcliffe Coefficient of Efficiency (NSCE) of 0.80 during the validation period (2004-2009). Model error estimates were within 10% of the natural variability of the lake. Our analysis indicated that fluctuations in Lake Turkana water levels are mainly driven by lake inflows and over-the-lake evaporation. Over-the-lake rainfall contributes only up to 30% of lake evaporative demand. During the modelling time period, Lake Turkana showed seasonal variations of 1-2m. The lake level fluctuated in the range up to 4m between the years 1998-2009. This study demonstrated the usefulness of satellite altimetry data to calibrate and validate the satellite-driven hydrological model for Lake Turkana without using any in-situ data. Furthermore, for Lake Turkana, we identified and outlined opportunities and challenges of using a calibrated satellite-driven water balance

  15. A multi-source satellite data approach for modelling Lake Turkana water level: calibration and validation using satellite altimetry data

    Directory of Open Access Journals (Sweden)

    N. M. Velpuri

    2012-01-01

    Full Text Available Lake Turkana is one of the largest desert lakes in the world and is characterized by high degrees of inter- and intra-annual fluctuations. The hydrology and water balance of this lake have not been well understood due to its remote location and unavailability of reliable ground truth datasets. Managing surface water resources is a great challenge in areas where in-situ data are either limited or unavailable. In this study, multi-source satellite-driven data such as satellite-based rainfall estimates, modelled runoff, evapotranspiration, and a digital elevation dataset were used to model Lake Turkana water levels from 1998 to 2009. Due to the unavailability of reliable lake level data, an approach is presented to calibrate and validate the water balance model of Lake Turkana using a composite lake level product of TOPEX/Poseidon, Jason-1, and ENVISAT satellite altimetry data. Model validation results showed that the satellite-driven water balance model can satisfactorily capture the patterns and seasonal variations of the Lake Turkana water level fluctuations with a Pearson's correlation coefficient of 0.90 and a Nash-Sutcliffe Coefficient of Efficiency (NSCE of 0.80 during the validation period (2004–2009. Model error estimates were within 10% of the natural variability of the lake. Our analysis indicated that fluctuations in Lake Turkana water levels are mainly driven by lake inflows and over-the-lake evaporation. Over-the-lake rainfall contributes only up to 30% of lake evaporative demand. During the modelling time period, Lake Turkana showed seasonal variations of 1–2 m. The lake level fluctuated in the range up to 4 m between the years 1998–2009. This study demonstrated the usefulness of satellite altimetry data to calibrate and validate the satellite-driven hydrological model for Lake Turkana without using any in-situ data. Furthermore, for Lake Turkana, we identified and outlined opportunities and challenges of using a calibrated

  16. Parameterization of the Non-Local Thermodynamic Equilibrium Source Function with Chemical Production by an Equivalent Two-Level Model

    Institute of Scientific and Technical Information of China (English)

    XunZHU

    2003-01-01

    The classic two-level or equivalent two-level model that includes only the statistical equilibrium of radiative and thermal processes of excitation and quenching between two vibrational energy levels is extended by adding chemical production to the rate equations. The modifications to the non-local thermodynamic equilibrium source function and cooling rate are parameterized by Φc, which characterizes the ratio of chemical production to collisional quenching. For applications of broadband emission of O3 at 9.6 μm, the non-LTE effect of chemical production on the cooling rate and limb emission is proportional to the ratio of O to O3. For a typical [O]/[O3], the maximum enhancements of limb radiance and cooling rate are about 15%-30% and 0.03-0.05 K day-1, respectively, both occurring near the mesopause regions.This suggests that the broadband limb radiance above ~80 km is sensitive to O3 density but not sensitive to the direct cooling rate along the line-of-sight, which makes O3 retrieval feasible but the direct coolingrate retrieval difficult by using the O3 9.6 μm band limb emission.

  17. Intense ultrasonic clicks from echolocating toothed whales do not elicit anti-predator responses or debilitate the squid Loligo pealeii

    DEFF Research Database (Denmark)

    Wilson, Maria; Hanlon, R.T.; Tyack, P.L.;

    2007-01-01

    Toothed whales use intense ultrasonic clicks to echolocate prey and it has been hypothesized that they also acoustically debilitate their prey with these intense sound pulses to facilitate capture. Cephalopods are an important food source for toothed whales, and there has probably been an...... evolutionary selection pressure on cephalopods to develop a mechanism for detecting and evading sound-emitting toothed whale predators. Ultrasonic detection has evolved in some insects to avoid echolocating bats, and it can be hypothesized that cephalopods might have evolved similar ultrasound detection as an......) do not acoustically debilitate this cephalopod species....

  18. One-pot synthesis of hyperbranched poly(amido amine) clicked with a sugar shell via Michael addition polymerization and thiol click reaction

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    This paper reports the production of glycopolymers via a simple and flexible method.A novel glycopolymer with a hyperbranched poly(amido amine) core and a sugar shell (HPAA-GLc) was synthesized by using thiol-ene click reaction via facile one-pot method.Hyperbranched poly(amido amine) with vinyl terminals was first synthesized by Michael addition polymerization of N,N’-methylene bisacrylamide (MBA) with 1-(2-aminoethyl) piperazine (AEPZ).Subsequently,thiol-ene click reaction between vinyl units of hyperbranched poly(amido amine) and thio-glucose was performed in situ.Based on the NMR result,all the vinyl groups reacted with thiol-glucose in 120 min.Strong photoluminescence emission was observed from the aqueous solution of HPAA-GLc.

  19. The Evolution of Click-n-Mortar E-tailing in Denmark

    DEFF Research Database (Denmark)

    Bøge Sørensen, Lars; Holst, Lisa L.

    2003-01-01

    The paper at hand presents an extension and application of Kotzab & Madlbergers (Kotzab &Madlberger, 2001) original clicks-and-mortar web-scan framework, which is here used to reexaminethe click-and-mortar activities of the top 100 Danish retailers and compare with resultsfrom the identical study...... last year. The first part of the paper describes the development andrationale behind the model used, the second part describes the results obtained and describes theevolution by analysing data from 2001, 2002 and 2003. The empirical results show a shifttoward selling in the internet channel, and a...

  20. Click Chemistry for the Synthesis of RGD-Containing Integrin Ligands

    Directory of Open Access Journals (Sweden)

    Matteo Colombo

    2010-01-01

    Full Text Available In the last few years click chemistry reactions, and in particular coppercatalyzed cycloadditions, have been used intensively for the preparation of new bioconjugate molecules and materials applicable to biomedical and pharmaceutical areas. This review will be focused on conjugates of the tripeptide Arg-Gly-Asp formed by means of click chemistry reactions. This sequence is a well known binding motif for specific transmembrane proteins and is involved in cellular adhesion to the extracellular matrix, allowing the selective recognition of the biomolecule or polymer in which it is incorporated.

  1. 64Cu Core-labeled Nanoparticles with High Specific Activity via Metal-Free Click Chemistry

    OpenAIRE

    Zeng, Dexing; Lee, Nam S.; Liu, Yongjian; Zhou, Dong; Dence, Carmen S.; Wooley, Karen L.; Katzenellenbogen, John A.; Welch, Michael J.

    2012-01-01

    A novel strategy based on metal-free click chemistry was developed for the copper-64 radiolabeling of the core in shell-crosslinked nanoparticles (SCK-NPs). Compared with Cu(I)-catalyzed click chemistry, this metal-free strategy provides the following advantages for Cu-64 labeling of the core of SCK-NPs: (1) elimination of copper exchange between non-radioactive Cu in the catalyst and DOTA-chelated Cu-64; (2) elimination of the internal “click” reactions between the azide and acetylene groups...

  2. Synthesis of click-reactive HPMA copolymers using RAFT polymerization for drug delivery applications

    DEFF Research Database (Denmark)

    Ebbesen, Morten F; Schaffert, D.H.; Crowley, Michael L;

    2013-01-01

    This study describes a versatile strategy combining reversible addition fragmentation transfer (RAFT) polymerization and click chemistry to synthesize well-defined, reactive copolymers of N-(2-hydroxypropyl)methacrylamide (HPMA) for drug delivery applications. A novel azide containing monomer N-(3......-alkyne cycloaddition (CuAAC) was demonstrated by efficient conjugation (up to 92%) of phosphocholine, a near infrared dye, and poly(ethylene glycol) (PEG) with different substitution degrees, either alone or in combination. This study introduces a novel and versatile method to synthesize well-defined click-reactive...

  3. Modelling and control of a seven level NPC voltage source inverter. Application to high power induction machine drive

    Science.gov (United States)

    Gheraia, H.; Berkouk, E. M.; Manesse, G.

    2001-08-01

    In this paper, we study a new kind of continuous-alternating converters: a seven-level neutral point clamping (NPC) voltage source inverter (VSI). We propose this inverter for applications in high voltage and high power fields. In the first part, we develop the knowledge and the control models of this inverter using the connections functions of the semi-conductors. After that, we present two pulse width modulation (PWM) algorithms to control this converter using its control model. We propose these algorithms for digital implementation. This multilevel inverter is associated to the induction machine. The performances obtained are full of promise to use it in the high voltage and high power fields of electrical traction.

  4. Modelling and control of a seven level NPC voltage source inverter. Application to high power induction machine drive

    Energy Technology Data Exchange (ETDEWEB)

    Gheraia, H.; Berkouk, E.M. [ENP, Alger (Algeria). Lab. de Commande des Processus; Manesse, G. [CNAM-Paris (France). Lab. d' Electricite Industrielle

    2001-08-01

    In this paper, we study a new kind of continuous-alternating converters: a seven-level neutral point clamping (NPC) voltage source inverter (VSI). We propose this inverter for applications in high voltage and high power fields. In the first part, we develop the knowledge and the control models of this inverter using the connections functions of the semi-conductors. After that, we present two pulse width modulation (PWM) algorithms to control this converter using its control model. We propose these algorithms for digital implementation. This multilevel inverter is associated to the induction machine. The performances obtained are full of promise to use it in the high voltage and high power fields of electrical traction. (orig.)

  5. BLT [Breach, Leach, and Transport]: A source term computer code for low-level waste shallow land burial

    International Nuclear Information System (INIS)

    We developed a source term model for low-level waste shallow land burial facilities by separating the problem into four individual compartments: (1) water flow, (2) corrosion and subsequent breaching of containers, (3) leaching of the waste forms, and (4) solute transport. For the first and the last compartments, we adopted the existing codes, FEMWATER and FEMWASTE, respectively. We wrote two new modules for the other two compartments in the form of two separate Fortran subroutines - BREACH and LEACH. They were incorporated into a modified version of the transport code FEMWASTE. The resultant code, which contains all three modules of container breaching waste form leaching and solute transport, was renamed BLT (for Breach, Leach, and Transport). This paper summarizes the overall program structure and logistics, and presents two examples from the results of verification and sensitivity tests. 6 refs., 7 figs., 1 tab

  6. Dose levels at coronary CT angiography - a comparison of Dual Energy-, Dual Source- and 16-slice CT

    Energy Technology Data Exchange (ETDEWEB)

    Kerl, J.M.; Bauer, Ralf W.; Maurer, Tobias B.; Aschenbach, Rene; Korkusuz, Huedayi; Lehnert, Thomas; Deseive, Simon; Vogl, Thomas J. [Johann Wolfgang Goethe-University, Department of Diagnostic and Interventional Radiology, Frankfurt (Germany); HELIOS Clinics Erfurt, Department of Diagnostic and Interventional Radiology and Neuroradiology, Erfurt (Germany); Ackermann, Hanns [Johann Wolfgang Goethe-University, Department of Biomathematics, Frankfurt (Germany); HELIOS Clinics Erfurt, Department of Diagnostic and Interventional Radiology and Neuroradiology, Erfurt (Germany)

    2011-03-15

    To compare the dose estimates and image quality of Dual Energy CT (DECT), Dual Source CT (DSCT) and 16-slice CT for coronary CT angiography (cCTA). Sixty-eight patients were examined with 16 - slice MDCT (group 1), 68 patients with DSCT (group 2) and 68 patients using DSCT in dual energy mode (DECT group 3). CT dose index volume, dose length product, effective dose, signal-to-noise, and contrast-to-noise ratio were compared. Subjective image quality was rated by two observers, blinded to technique. The mean estimated radiation dose of all patients investigated on a 16 - slice MDCT was 12 {+-} 3.59 mSv, for DSCT in single energy 9.8 {+-} 4.77 mSv and for DECT 4.54 {+-} 1.87 mSv. Dose for CTA was significantly lower in group 3 compared to group 1 and 2. The image noise was significantly lower in Group 2 in comparison to group 1 and group 3. There was no significant difference in diagnostic image quality comparing DECT and DSCT. cCTA shows better dose levels at both DECT and DSCT compared to 16-slice CT. Further, DECT delivers significantly less dose than regular DSCT or single source single energy cCTA while maintaining diagnostic image quality. (orig.)

  7. The Potential of Open Source Information in Supporting Acquisition Pathway Analysis to Design IAEA State Level Approaches

    International Nuclear Information System (INIS)

    International Atomic Energy Agency (IAEA) safeguards designed to deter nuclear proliferation are constantly evolving to respond to new challenges. Within its State Level Concept, the IAEA envisions an objective-based and information-driven approach for designing and implementing State Level Approaches (SLAs), using all available measures to improve the effectiveness and efficiency of safeguards. The main Objectives of a SLA are a) to detect undeclared nuclear material or activities in the State, b) to detect undeclared production or processing of nuclear materials in declared facilities or locations outside facilities (LOFs), c) to detect diversion of declared nuclear material in declared facilities or LOFs. Under the SLA, States will be differentiated based upon objective State-Specific Factors that influence the design, planning, conduct and evaluation of safeguards activities. Proposed categories of factors include both technical and legal aspects, spanning from the deployed fuel cycle and the related state's technical capability to the type of safeguards agreements in force and the IAEA experience in implementing safeguards in that state. To design a SLA, the IAEA foresees the use of Acquisition Path Analysis (APA) to identify the plausible routes for acquiring weapons-usable material and to assess their safeguards significance. In order to achieve this goal, APA will have to identify possible acquisition paths, characterize them and eventually prioritize them. This paper will provide an overview of how the use of open source information (here loosely defined as any type of non-classified or proprietary information and including, but not limited to, media sources, government and non-governmental reports and analyzes, commercial data, satellite imagery, scientific/ technical literature, trade data) can support this activity in the various aspects of a typical APA approach. (author)

  8. Interaction of BODIPY dyes with bovine serum albumin: a case study on the aggregation of a click-BODIPY dye.

    Science.gov (United States)

    Jameson, Laramie P; Smith, Nicholas W; Annunziata, Onofrio; Dzyuba, Sergei V

    2016-06-01

    The fluorescence of BODIPY and click-BODIPY dyes was found to substantially increase in the presence of bovine serum albumin (BSA). BSA acted as a solubilizer for dye aggregates, in addition to being a conventional binding scaffold for the click-BODIPY dyes, indicating that disaggregation of fluorophores should be considered when evaluating dye-protein interactions. PMID:27173791

  9. Radiation exposure of the population and indoor radiation levels in The Netherlands caused by natural gamma sources

    International Nuclear Information System (INIS)

    An estimate has been made of gamma doses to the population in the Netherlands, caused by natural radiation sources encountered in the environment. Data are given, derived from two independent types of measurements: 1. Exposure/dose rate measurements in the living environment (private houses as well as workplaces), using a high pressure ionization chamber and thermoluminescent dosemeters (TLD) respectively and 2. Individual monitoring, using TLD. The study included some 750 individuals, 400 houses and 275 workplaces. The participants were selected and divided into two groups on the basis of their location in areas of relatively high and low terrestrial radiation level respectively. Distinction was made between three categories of individuals with respect to their patterns of life. An estimate was made of the influence of the terrestrial component of the natural background and of some typical building materials on the indoor radiation level. An average indoor exposure rate of 9.4 μR.h-1 (6.7 x 10-13 C0144.s)-1) and a dose rate of 9.3 μrad.h-1 (93 nGy.h-1) for individuals were found, both with a standard deviation of 15-20%. (Auth.)

  10. A solubility-limited-source-term model for the geological disposal of cemented intermediate-level waste

    International Nuclear Information System (INIS)

    This paper presents and illustrates the use of a source-team model for an intermediate-level radioactive-waste repository. The model deals with the behaviour of long-lived nuclides after the initial containment period. The major processes occurring in the near-field are included, namely sorption, elemental solubility limits, chain decay and transport due to groundwater flow. The model is applied to a realistic example of ILW disposal. From this it is clear that some nuclides are present in sufficient quantities to reach their solubility limit even when the assumed sorption coefficients are large. For these nuclides the precise sorption coefficient is unimportant. It is also clear that some daughter products, in particular Pb-210, become significant. The toxicity of the repository porewater is calculated and it is shown that, although this toxicity is high compared to levels acceptable in drinking water, it is much lower than the toxicity of the waste itself. However, the near-field chemical environment is only one of a number of containment barriers. In addition, it has been shown that the rate at which radionuclides enter the rock surrounding the repository is very low. (author)

  11. A solubility-limited source-term model for the geological disposal of cemented intermediate-level waste

    International Nuclear Information System (INIS)

    This paper presents and illustrates the use of a source-term model for an intermediate-level radioactive-waste repository. The model deals with the behaviour of long-lived nuclides after the initial containment period. The major processes occurring in the near field are included, namely sorption, elemental solubility limits, chain decay and transport due to groundwater flow. The model is applied to a realistic example of ILW disposal. From this it is clear that some nuclides are present in sufficient quantities to reach their solubility limit even when the assumed sorption coefficients are large. For these nuclides the precise sorption coefficient is unimportant. It is also clear that some daughter products, in particular Pb-210, become significant. The toxicity of the repository pore water is calculated and it is shown that, although this toxicity is high compared to levels acceptable in drinking water, it is much lower than the toxicity of the waste itself. However, the near-field chemical environment is only one of a number of containment barriers. In addition, it has been shown that the rate at which radionuclides enter the rock surrounding the repository is very low. (author)

  12. Parameterization of the Non-Local Thermodynamic Equilibrium Source Function with Chemical Production by an Equivalent Two-Level Model

    Institute of Scientific and Technical Information of China (English)

    Xun ZHU

    2003-01-01

    The classic two-level or equivalent two-level model that includes only the statistical equilibriumof radiative and thermal processes of excitation and quenching between two vibrational energy levelsis extended by adding chemical production to the rate equations. The modifications to the non-localthermodynamic equilibrium source function and cooling rate are parameterized by φc, which characterizesthe ratio of chemical production to collisional quenching. For applications of broadband emission of O3 at9.6 μm, the non-LTE effect of chemical production on the cooling rate and limb emission is proportionalto the ratio of O to O3. For a typical [O]/[O3], the maximum enhancements of limb radiance and coolingrate are about 15%-30% and 0.03-0.05 K day-1, respectively, both occurring near the mesopause regions.This suggests that the broadband limb radiance above ~80 km is sensitive to O3 density but not sensitiveto the direct cooling rate along the line-of-sight, which makes O3 retrieval feasible but the direct coolingrate retrieval difficult by using the O3 9.6 μm band limb emission.

  13. 40 CFR Table 3 to Subpart Dd of... - Tank Control Levels for Tanks at Existing Affected Sources as Required by 40 CFR 63.685(b)(1)

    Science.gov (United States)

    2010-07-01

    ... Existing Affected Sources as Required by 40 CFR 63.685(b)(1) 3 Table 3 to Subpart DD of Part 63 Protection... Hazardous Air Pollutants from Off-Site Waste and Recovery Operations Pt. 63, Subpt. DD, Table 3 Table 3 to Subpart DD of Part 63—Tank Control Levels for Tanks at Existing Affected Sources as Required by 40 CFR...

  14. 40 CFR Table 4 to Subpart Dd of... - Tank Control Levels for Tanks at New Affected Sources as Required by 40 CFR 63.685(b)(2)

    Science.gov (United States)

    2010-07-01

    ... Affected Sources as Required by 40 CFR 63.685(b)(2) 4 Table 4 to Subpart DD of Part 63 Protection of... Hazardous Air Pollutants from Off-Site Waste and Recovery Operations Pt. 63, Subpt. DD, Table 4 Table 4 to Subpart DD of Part 63—Tank Control Levels for Tanks at New Affected Sources as Required by 40 CFR...

  15. Effects of monochromatic light sources on sex hormone levels in serum and on semen quality of ganders.

    Science.gov (United States)

    Chang, Shen-Chang; Zhuang, Zi-Xuan; Lin, Min-Jung; Cheng, Chuen-Yu; Lin, Tsung-Yi; Jea, Yu-Shine; Huang, San-Yuan

    2016-04-01

    Light is an essential external factor influencing various physiological processes, including reproductive performance, in birds. Although several attempts have been made to understand the effect of light on poultry production, the effect of light of a particular wavelength (color) on the reproductive function in geese remains unclear. This study evaluated the effect of various monochromatic light sources on the levels of sex hormone and on semen quality of ganders. Of 30 male White Roman geese in their third reproductive season (average age=3years), 27 were divided into three groups receiving monochromatic white or red or blue lights. The birds were kept in an environmentally controlled house with a lighting photoperiod of 7L:17D for six weeks as the adaptation period. The photoperiod was subsequently changed to 9L:15D and maintained for 24 weeks. Three ganders at the beginning of the study and three from each group at the end of the adjusting period and the 20th and 30th week of the study period were sacrificed, and their testes and blood samples were collected for determining the sex hormone levels. Semen samples were collected for determining semen quality parameters, including the semen collection index, sperm concentration, semen volume, sperm motility, sperm viability, sperm morphology, and semen quality factor. The results showed that the testosterone and estradiol levels remained unchanged in all three groups at all time points. The ratio of testosterone to estradiol of ganders exposed to white light was significantly higher than that of ganders exposed to red light at the 30th week (Pblue light were significantly the lowest (Pblue lights in ganders. PMID:26919910

  16. Vertical-aware click model-based effectiveness metrics

    NARCIS (Netherlands)

    I. Markov; E. Kharitonov; V. Nikulin; P. Serdyukov; M. de Rijke; F. Crestani

    2014-01-01

    Today's web search systems present users with heterogeneous information coming from sources of different types, also known as verticals. Evaluating such systems is an important but complex task, which is still far from being solved. In this paper we examine the hypothesis that the use of models that

  17. Surface Modification of Nanoporous 1,2-Polybutadiene by Atom Transfer Radical Polymerization or Click Chemistry

    DEFF Research Database (Denmark)

    Guo, Fengxiao; Jankova Atanasova, Katja; Schulte, Lars;

    2010-01-01

    Surface-initiated atom transfer radical polymerization (ATRP) and click chemistry were used to obtain functional nanoporous polymers based oil nanoporous 1,2-polybutadiene (PB) with gyroid morphology. The ATRP monolith initiator was prepared by immobilizing bromoester initiators onto the pore walls...

  18. A Click Chemistry Approach towards Flavin-Cyclodextrin Conjugates—Bioinspired Sulfoxidation Catalysts

    Directory of Open Access Journals (Sweden)

    Petra Tomanová

    2015-11-01

    Full Text Available A click chemistry approach based on the reaction between alkynylflavins and mono(6-azido-6-deoxy-β-cyclodextrin has proven to be a useful tool for the synthesis of flavin-cyclodextrin conjugates studied as monooxygenase mimics in enantioselective sulfoxidations.

  19. A DOTA-peptide conjugate by copper-free click chemistry

    OpenAIRE

    Martin, Molly E.; Parameswarappa, Sharavathi G.; O’Dorisio, M. Sue; Pigge, F. Christopher; Schultz, Michael K.

    2010-01-01

    Attachment of DOTA to a novel monofluoro-cyclooctyne facilitates bioconjugation to an azide-modified peptide via Cu-free click chemistry. The resulting conjugate was radiolabeled with 111In to afford a potential targeted molecular imaging agent with high specific activity and in excellent radiochemical purity.

  20. Synthesis of a hexasaccharide partial sequence of hyaluronan for click chemistry and more

    Directory of Open Access Journals (Sweden)

    Marina Bantzi

    2015-04-01

    Full Text Available In the present work, the synthesis of a hexasaccharide partial sequence of hyaluronan equipped with a terminal azido moiety is reported. This hexasaccharide can be used for the attachment on surfaces by means of click chemistry and after suitable deprotection for biophysical studies.

  1. A Click Chemistry Approach towards Flavin-Cyclodextrin Conjugates-Bioinspired Sulfoxidation Catalysts

    Czech Academy of Sciences Publication Activity Database

    Tomanová, P.; Šturala, J.; Buděšínský, Miloš; Cibulka, R.

    2015-01-01

    Roč. 20, č. 11 (2015), s. 19837-19848. ISSN 1420-3049 Institutional support: RVO:61388963 Keywords : click chemistry * cyclodextrin * flavin * monooxygenase * oxidation * sulfoxides * green chemistry Subject RIV: CC - Organic Chemistry Impact factor: 2.416, year: 2014 http://www.mdpi.com/1420-3049/20/11/19667/htm

  2. A click chemistry-based microRNA maturation assay optimized for high-throughput screening.

    Science.gov (United States)

    Lorenz, Daniel A; Garner, Amanda L

    2016-07-01

    Catalytic enzyme-linked click-chemistry assays (cat-ELCCA) are an emerging class of biochemical assay. Herein we report on expanding the toolkit of cat-ELCCA to include the kinetically superior inverse-electron demand Diels-Alder (IEDDA) reaction. The result is a technology with improved sensitivity and reproducibility, enabling automated high-throughput screening. PMID:27284591

  3. Triazolinediones enable ultrafast and reversible click chemistry for the design of dynamic polymer systems

    Science.gov (United States)

    Billiet, Stijn; de Bruycker, Kevin; Driessen, Frank; Goossens, Hannelore; van Speybroeck, Veronique; Winne, Johan M.; Du Prez, Filip E.

    2014-09-01

    With its focus on synthetic reactions that are highly specific and reliable, ‘click’ chemistry has become a valuable tool for many scientific research areas and applications. Combining the modular, covalently bonded nature of click-chemistry linkages with an ability to reverse these linkages and reuse the constituent reactants in another click reaction, however, is a feature that is not found in most click reactions. Here we show that triazolinedione compounds can be used in click-chemistry applications. We present examples of simple and ultrafast macromolecular functionalization, polymer-polymer linking and polymer crosslinking under ambient conditions without the need for a catalyst. Moreover, when triazolinediones are combined with indole reaction partners, the reverse reaction can also be induced at elevated temperatures, and the triazolinedione reacted with a different reaction partner, reversibly or irreversibly dependent on its exact nature. We have used this ‘transclick’ reaction to introduce thermoreversible links into polyurethane and polymethacrylate materials, which allows dynamic polymer-network healing, reshaping and recycling.

  4. Click chemistry for attachment of targeting moieties to polymer drug carriers

    Czech Academy of Sciences Publication Activity Database

    Pola, Robert; Pechar, Michal; Ulbrich, Karel

    Herceg Novi: Materials Research Society of Serbia , 2013. s. 140. [Annual Conference YUCOMAT 2013 /15./. 02.09.2013-06.09.2013, Herceg Novi] R&D Projects: GA MŠk EE2.3.30.0029 Institutional support: RVO:61389013 Keywords : HPMA * peptides * "click" chemistry Subject RIV: CE - Biochemistry

  5. Extraction of pulse repetition intervals from sperm whale click trains for ocean acoustic data mining.

    Science.gov (United States)

    Zaugg, Serge; van der Schaar, Mike; Houégnigan, Ludwig; André, Michel

    2013-02-01

    The analysis of acoustic data from the ocean is a valuable tool to study free ranging cetaceans and anthropogenic noise. Due to the typically large volume of acquired data, there is a demand for automated analysis techniques. Many cetaceans produce acoustic pulses (echolocation clicks) with a pulse repetition interval (PRI) remaining nearly constant over several pulses. Analyzing these pulse trains is challenging because they are often interleaved. This article presents an algorithm that estimates a pulse's PRI with respect to neighboring pulses. It includes a deinterleaving step that operates via a spectral dissimilarity metric. The sperm whale (SW) produces trains with PRIs between 0.5 and 2 s. As a validation, the algorithm was used for the PRI-based identification of SW click trains with data from the NEMO-ONDE observatory that contained other pulsed sounds, mainly from ship propellers. Separation of files containing SW clicks with a medium and high signal to noise ratio from files containing other pulsed sounds gave an area under the receiver operating characteristic curve value of 0.96. This study demonstrates that PRI can be used for the automated identification of SW clicks and that deinterleaving via spectral dissimilarity contributes to algorithm performance. PMID:23363108

  6. Freedom of Contract in Click Wrap Agreements in Malaysia and the United States of America

    Directory of Open Access Journals (Sweden)

    Maryam Rafiei

    2011-06-01

    Full Text Available Technological advancement in the communications industry, particularly over the last decade, has given rise to consumers and commercial providers who want to form their own business or contractual agreements via the Internet. The mark of such technology can be seen in a new form of contract called “click wrap.”

  7. Multi-channel services for click and mortars: development of a design method

    NARCIS (Netherlands)

    Simons, L.P.A.

    2006-01-01

    The rise of Internet commerce led to multiple predictions of disintermediation and the decline of physical shopping. However, a "click and mortar" approach, which combines online, offline and telephone contact, has added value for customers and for supplier profitability, as recent research confirms

  8. Freedom of Contract in Click Wrap Agreements in Malaysia and the United States of America

    OpenAIRE

    Maryam Rafiei; Nazura Abdul Manap

    2011-01-01

    Technological advancement in the communications industry, particularly over the last decade, has given rise to consumers and commercial providers who want to form their own business or contractual agreements via the Internet. The mark of such technology can be seen in a new form of contract called “click wrap.”

  9. Low level impurities in imported wheat are a likely source of feral transgenic oilseed rape (Brassica napus L.) in Switzerland.

    Science.gov (United States)

    Schulze, Juerg; Brodmann, Peter; Oehen, Bernadette; Bagutti, Claudia

    2015-11-01

    In Switzerland, the cultivation of genetically modified (GM) oilseed rape (Brassica napus L.) and the use of its seeds for food and feed are not permitted. Nevertheless, the GM oilseed rape events GT73, MS8×RF3, MS8 and RF3 have recently been found in the Rhine port of Basel, Switzerland. The sources of GM oilseed rape seeds have been unknown. The main agricultural good being imported at the Rhine port of Basel is wheat and from 2010 to 2013, 19% of all Swiss wheat imports originated from Canada. As over 90% of all oilseed rape grown in Canada is GM, we hypothesised that imports of Canadian wheat may contain low level impurities of GM oilseed rape. Therefore, waste fraction samples gathered during the mechanical cleaning of Canadian wheat from two Swiss grain mills were analysed by separating oilseed rape seeds from waste fraction samples and testing DNA of pooled seeds for the presence of transgenes by real-time PCR. Furthermore, oilseed rape seeds from each grain mill were sown in a germination experiment, and seedling DNA was tested for the presence of transgenes by real-time PCR. GT73, MS8×RF3, MS8 and RF3 oilseed rape was detected among seed samples and seedlings of both grain mills. Based on this data, we projected a mean proportion of 0.005% of oilseed rape in wheat imported from Canada. Besides Canadian wheat, the Rhine port of Basel does not import any other significant amounts of agricultural products from GM oilseed rape producing countries. We therefore conclude that Canadian wheat is the major source of unintended introduction of GM oilseed rape seeds into Switzerland. PMID:26109224

  10. Insights into the molecular level composition, sources, and formation mechanisms of dissolved organic matter in aerosols and precipitation

    Science.gov (United States)

    Altieri, Katye Elisabeth

    Atmospheric aerosols scatter and absorb light influencing the global radiation budget and climate, and are associated with adverse effects on human health. Precipitation is an important removal mechanism for atmospheric dissolved organic matter (DOM), and a potentially important input for receiving ecosystems. However, the sources, formation, and composition of atmospheric DOM in aerosols and precipitation are not well understood. This dissertation investigates the composition and formation mechanisms of secondary organic aerosol (SOA) formed through cloud processing reactions, elucidates the composition and sources of DOM in rainwater, and provides links connecting the two. Photochemical batch aqueous-phase reactions of organics with both biogenic and anthropogenic sources (i.e., methylglyoxal, pyruvic acid) and OH radical were performed to simulate cloud processing. The composition of products formed through cloud processing experiments and rainwater collected in New Jersey, USA was investigated using a combination of electrospray ionization mass spectrometry techniques, including ultra-high resolution Fourier transform ion cyclotron resonance mass spectrometry. This dissertation has resulted in the first evidence that oligomers form through cloud processing reactions, the first detailed chemical mechanism of aqueous phase oligomerization, the first identification of oligomers, organosulfates, and nitrooxy organosulfates in precipitation, and the first molecular level chemical characterization of organic nitrogen in precipitation. The formation of oligomers in SOA helps to explain the presence of large multifunctional compounds and humic like substances (HULIS) that dominate particulate organic mass. Oligomers have low vapor pressures and remain in the particle phase after cloud evaporation, enhancing SOA. The chemical properties of the oligomers suggest that they are less hygroscopic than the monomeric reaction products (i.e., organic acids). Their elemental

  11. A 7-Level Single DC Source Cascaded H-Bridge Multilevel Inverter with a Modified DTC Scheme for Induction Motor-Based Electric Vehicle Propulsion

    OpenAIRE

    Farid Khoucha; Khoudir Marouani; Mohamed Benbouzid; Abdelaziz Kheloui; Abdeslam Mamoune

    2013-01-01

    International audience This paper presents a new hybrid cascaded H-bridge multilevel inverter motor drive DTC scheme for electric vehicles where each phase of the inverter can be implemented using a single DC source. Traditionally, each phase of the inverter requires n DC source for (2n + 1) output voltage levels. In this paper, a scheme is proposed that allows the use of a single DC source as the first DC source which would be available from batteries or fuel cells, with the remaining (n ...

  12. The mechanics of unrest at Long Valley caldera, California: 1. Modeling the geometry of the source using GPS, leveling and two-color EDM data

    Science.gov (United States)

    Battaglia, Maurizio; Segall, P.; Murray, J.; Cervelli, Peter; Langbein, J.

    2003-01-01

    We surveyed 44 existing leveling monuments in Long Valley caldera in July 1999, using dual frequency global positioning system (GPS) receivers. We have been able to tie GPS and leveling to a common reference frame in the Long Valley area and computed the vertical deformation by differencing GPS-based and leveled orthometric heights. The resurgent dome uplifted 74??7 cm from 1975 to 1999. To define the inflation source, we invert two-color EDM and uplift data from the 1985-1999 unrest period using spherical or ellipsoidal sources. We find that the ellipsoidal source satisfies both the vertical and horizontal deformation data, whereas the spherical point source cannot. According to our analysis of the 1985-1999 data, the main source of deformation is a prolate ellipsoid located beneath the resurgent dome at a depth of 5.9 km (95% bounds of 4.9-7.5 km). This body is vertically elongated, has an aspect ratio of 0.475 (95% bounds are 0.25-0.65) and a volume change of 0.086 km3 (95% bounds are 0.06-0.13 km3). Failure to account for the ellipsoidal nature of the source biases the estimated source depth by 2.1 km (35%), and the source volume by 0.038 km3 (44%). ?? 2003 Elsevier B.V. All rights reserved.

  13. Contributions to cities' ambient particulate matter (PM): A systematic review of local source contributions at global level

    OpenAIRE

    KARAGULIAN Federico; BELIS CLAUDIO; DORA Carlos Francisco; Prüss-Ustün, Annette; Bonjour, Sophie; ROHANI Heather; Ammann, Markus

    2015-01-01

    For reducing health impacts from air pollution, it is important to know the sources contributing to human exposure. This study systematically reviewed and analysed available source apportionment studies on particulate matter (of diameter of 10 and 2.5 microns, PM10 and PM2.5) performed in cities to estimate typical shares of the sources of pollution by country and by region. A database with city source apportionment records, estimated with the use of receptor models, was also deve...

  14. A New Radio Frequency Plasma Oxygen Primary Ion Source on Nano Secondary Ion Mass Spectrometry for Improved Lateral Resolution and Detection of Electropositive Elements at Single Cell Level.

    Science.gov (United States)

    Malherbe, Julien; Penen, Florent; Isaure, Marie-Pierre; Frank, Julia; Hause, Gerd; Dobritzsch, Dirk; Gontier, Etienne; Horréard, François; Hillion, François; Schaumlöffel, Dirk

    2016-07-19

    An important application field of secondary ion mass spectrometry at the nanometer scale (NanoSIMS) is the detection of chemical elements and, in particular, metals at the subcellular level in biological samples. The detection of many trace metals requires an oxygen primary ion source to allow the generation of positive secondary ions with high yield in the NanoSIMS. The duoplasmatron oxygen source is commonly used in this ion microprobe but cannot achieve the same quality of images as the cesium primary ion source used to produce negative secondary ions (C(-), CN(-), S(-), P(-)) due to a larger primary ion beam size. In this paper, a new type of an oxygen ion source using a rf plasma is fitted and characterized on a NanoSIMS50L. The performances of this primary ion source in terms of current density and achievable lateral resolution have been characterized and compared to the conventional duoplasmatron and cesium sources. The new rf plasma oxygen source offered a net improvement in terms of primary beam current density compared to the commonly used duoplasmatron source, which resulted in higher ultimate lateral resolutions down to 37 nm and which provided a 5-45 times higher apparent sensitivity for electropositive elements. Other advantages include a better long-term stability and reduced maintenance. This new rf plasma oxygen primary ion source has been applied to the localization of essential macroelements and trace metals at basal levels in two biological models, cells of Chlamydomonas reinhardtii and Arabidopsis thaliana. PMID:27291826

  15. Effects of two protein sources and energy level of diet on the performance of young Marchigiana bulls. 2. Meat quality

    Directory of Open Access Journals (Sweden)

    Federico Infascelli

    2010-01-01

    Full Text Available The aim of this trial was to study the influence of two protein sources (faba bean-FB vs soybean meal s.e.-SBM and two energy levels of diets given to young Marchigiana bulls on meat quality: water holding capacity (WHC, chemical composition, hydroxyproline and cholesterol contents, fatty acids profile of intramuscular, subcutaneous and perirenal adipose tissues. While chemical composition and WHC was determined only on muscle Longissimus thoracis (LT, hydroxyproline and cholesterol contents were evaluated also on muscles Semitendinosus (ST and Ileopsoas plus Psoas minor (IP. Eighteen young bulls were divided into three groups. Until the slaughter weight (620 kg was achieved, two groups, FB and SBM, were fed diets with similar protein and energy contents but differing in protein sources, and the third group was fed high energy (HE diets. Protein sources did not affect meat nutritional characteristics; but meat of group SBM had high hydroxyproline content: 62.6 vs 60.0 mg 100g-1, respectively, for SBM and FB groups (P<0.05, while compression losses were higher for FB group (7.6 vs 5.7%, respectively, for FB and SBM groups; P<0.01. As respects the comparison among content of hydroxyproline in the different muscles: IP, corresponding to the tenderloin, showed significantly lower concentrations than the other muscles (55.2 vs 60.7 and 63.5 mg 100g-1 for IP, LT and ST, respectively; P<0.01. Feeding regimes did not affect muscular cholesterol content (average values of 53.6, 55.5 and 52.1 mg 100g-1 of fresh muscle for FB, SBM and HE, respectively which was similar to the levels found in meat from specialised Italian beef breeds and lower than those from other breeds. As respects the differences in cholesterol contents among the muscles, IP showed lower contents than other muscles (50.9 vs 54.1, 56.0 mg 100g-1, respectively for IP, ST, LT; P<0.05. The higher energy diets induced higher concentration of saturated fatty acids, in particular of palmitic

  16. Sources and migration pathways of gases in rock salt with respect to high-level waste disposal

    International Nuclear Information System (INIS)

    Deep geologic salt formations are envisaged as suitable medium for the disposal of high level radioactive waste in the Federal Republic of Germany. One of the resulting effects is the generation of gases. Several mechanisms, such as corrosion, outgassing of the host rock, radiolysis etc., account for this gas generation, and are interrelated to each other. In case of HLW disposal in salt formations outgassing of the rock salt may contribute significantly to the source term of gas generation, in contrast to ILW, where the gas generation is mainly governed by the waste itself. The distribution of gases in rock salt is very heterogeneous, thus a determination of the gas content at the actual disposal horizon in the final repository seems necessary, in order to avoid those sections of the salt structure which contain high gas concentrations. The contribution to the gas generation by radiolytic reactions occurring in rock salt, in fluid inclusions and, before all voids have been completely closed, in the borehole atmosphere, is not fully understood. The final pressure in an emplacement borehole is determined by transport of gases through rock salt. Petrophysical parameters of rock salt, such as permeability, porosity, inner surface and diffusivity, determine this transport and some experimental values are given. 12 refs., 4 figs., 3 tabs

  17. Gender correlation of stress levels and sources of stress among first year students in a medical college.

    Science.gov (United States)

    Saxena, Yogesh; Shrivastava, Abha; Singhi, Priyanka

    2014-01-01

    Medical courses in India are very demanding for the students thus making career in medical education very stressful. The study was designed to determine the prevalence of stress levels in 100 first year medical students and to explore the sources of stress & it's relationship across the male and female students. Demographic information and Qualitative data from investigator tailored Medical Student Stress Questionnaire (MSSQ) by self rating under supervision of investigators were subjected to a thematic analysis. Stress perceived was more in males students (82.2%) as compared to females (61.8%) and their MSSQ index score was significantly different (U=985; P=0.02). Moderate to high academic stress was present among 79% of students more so in males with the academic domain score significantly different from that of females (U=883; P=0.007). Females perceived more stress in inter personal domain (12.7%) with the score significantly different from males (U=953.5; P=0.02). Group and Teaching stress was equally present in males and females. PMID:25509965

  18. Source identification and budget analysis on elevated levels of formaldehyde within the ship plumes: a ship-plume photochemical/dynamic model analysis

    OpenAIRE

    C. H. Song; Kim, H. S.; Glasow, R.; Brimblecombe, P.; Kim, J; R. J. Park; Woo, J. H.; Kim, Y H

    2010-01-01

    Elevated levels of formaldehyde (HCHO) along the ship corridors have been observed by satellite sensors, such as ESA/ERS-2 GOME (Global Ozone Monitoring Experiment), and were also simulated by global 3-D chemistry-transport models. In this study, three likely sources of the elevated HCHO levels in the ship plumes as well as their contributions to the elevated HCHO levels (budget) were investigated using a newly-developed ship-plume photochemical/dynamic model: (1) primary HC...

  19. Analysis of Physical, Chemical and Microbiological Pollution in one Right Click

    International Nuclear Information System (INIS)

    Current researches on the topic of indoor air pollution are moving towards expertise and prevention. Therefore it seems so critical to invest in the area of expertise and create a measuring device performing chemical, physical and bacteriological analysis in one click. Our choice of development towards this system of information management is oriented towards a modular system which can simultaneously transmit on real-time the analysis in the internet. Our production work has used several solutions and analyzed several possible methods such as microprocessor that has shown its reliability. The electronic system worked well even with some problems solved at the level of detection of particles α, β and γ. The solution NO-IP as for the transfer of data over the Internet has been successfully tested. In the same way we have been constrained to achieve measurement campaigns to verify the ability of the device to give consistent values. These campaigns were conducted on the Beaulieu of the University of Rennes 1, given the size of the site; it gives us a fairly comprehensive range of situations. These measurement campaigns extended for several months, with the purpose of comparing and analyzing the various results. These campaigns offer an opportunity of testing the operation of the aircraft and assessing the performance, knowing that all measures were compared to the device certified EN (Gasman). For the development of our device, we specify the direction and scope of the study area, analyze the existing level of detection performed and technical data manipulated, obtain a comprehensive description of the electronic system and reach a reasoned choice of a solution type of development. This allowed us to develop a multifunction prototype which objective is to control the quality of indoor air pollution in habitations. This device admits the same principle as product modem M2M (Machine to Machine). Through processes M2M, machinery (measuring instruments (device) and air

  20. Contributions to cities' ambient particulate matter (PM): A systematic review of local source contributions at global level

    Science.gov (United States)

    Karagulian, Federico; Belis, Claudio A.; Dora, Carlos Francisco C.; Prüss-Ustün, Annette M.; Bonjour, Sophie; Adair-Rohani, Heather; Amann, Markus

    2015-11-01

    For reducing health impacts from air pollution, it is important to know the sources contributing to human exposure. This study systematically reviewed and analysed available source apportionment studies on particulate matter (of diameter of 10 and 2.5 microns, PM10 and PM2.5) performed in cities to estimate typical shares of the sources of pollution by country and by region. A database with city source apportionment records, estimated with the use of receptor models, was also developed and available at the website of the World Health Organization. Systematic Scopus and Google searches were performed to retrieve city studies of source apportionment for particulate matter. Six source categories were defined. Country and regional averages of source apportionment were estimated based on city population weighting. A total of 419 source apportionment records from studies conducted in cities of 51 countries were used to calculate regional averages of sources of ambient particulate matter. Based on the available information, globally 25% of urban ambient air pollution from PM2.5 is contributed by traffic, 15% by industrial activities, 20% by domestic fuel burning, 22% from unspecified sources of human origin, and 18% from natural dust and salt. The available source apportionment records exhibit, however, important heterogeneities in assessed source categories and incompleteness in certain countries/regions. Traffic is one important contributor to ambient PM in cities. To reduce air pollution in cities and the substantial disease burden it causes, solutions to sustainably reduce ambient PM from traffic, industrial activities and biomass burning should urgently be sought. However, further efforts are required to improve data availability and evaluation, and possibly to combine with other types of information in view of increasing usefulness for policy making.

  1. Management and architecture click: The FAD(E)E Framework

    OpenAIRE

    Goethals, Frank; Snoeck, Monique; Lemahieu, Wilfried; Vandenbulcke, Jacques

    2006-01-01

    Enterprises are living things. They constantly need to be (re-)architected in order to achieve the necessary agility, alignment and integration. This paper gives a high-level overview of how companies can go about doing 'enterprise architecture' in the context of both the classic (isolated) enterprise and the Extended Enterprise. By discussing the goals that are pursued in an enterprise architecture effort we reveal some basic requirements that can be put on the process of architecting the en...

  2. PERFORMING DIAGNOSTICS ON THE SPALLATION NEUTRON SOURCE VISION BEAM LINE TO ELIMINATE HIGH VIBRATION LEVELS AND PROVIDE A SUSTAINABLE OPERATION

    Energy Technology Data Exchange (ETDEWEB)

    Van Hoy, Blake W [ORNL

    2014-01-01

    The Spallation Neutron Source (SNS) at the Oak Ridge National Laboratory (ORNL) provides variable energy neutrons for a variety of experiments. The neutrons proceed down beam lines to the experiment hall, which houses a variety of experiments and test articles. Each beam line has one or more neutron choppers which filter the neutron beam based on the neutron energy by using a rotating neutron absorbing material passing through the neutron beam. Excessive vibration of the Vision beam line, believed to be caused by the T0 chopper, prevented the Vision beam line from operating at full capacity. This problem had been addressed several times by rebalancing/reworking the T0 beam chopper but the problem stubbornly persisted. To determine the cause of the high vibration, dynamic testing was performed. Twenty-seven accelerometer and motor current channels of data were collected during drive up, drive down, coast down, and steady-state conditions; resonance testing and motor current signature analysis were also performed. The data was analyzed for traditional mechanical/machinery issues such as misalignment and imbalance using time series analysis, frequency domain analysis, and operating deflection shape analysis. The analysis showed that the chopper base plate was experiencing an amplified response to the excitation provided by the T0 beam chopper. The amplified response was diagnosed to be caused by higher than expected base plate flexibility, possibly due to improper grouting or loose floor anchors. Based on this diagnosis, a decision was made to dismantle the beam line chopper and remount the base plate. Neutron activation of the beam line components make modifications to the beam line especially expensive and time consuming due to the radiation handling requirements, so this decision had significant financial and schedule implications. It was found that the base plate was indeed loose because of improper grouting during its initial installation. The base plate was

  3. Determining seasonal greenhouse gas emissions from ground-level area sources in a dairy operation in central Texas.

    Science.gov (United States)

    Borhan, M S; Capareda, Sergio; Mukhtar, Saqib; Faulkner, William B; McGee, Russell; Parnell, Calvin B

    2011-07-01

    Greenhouse gas (GHG) emissions from agricultural production operations are recognized as an important air quality issue. A new technique following the U.S. Environmental Protection Agency Method TO-14A was used to measure GHG emissions from ground-level area sources (GLAS) in a free-stall dairy operation in central Texas. The objective of this study was to quantify and report GHG emission rates (ERs) from the dairy during the summer and winter using this protocol. A weeklong sampling was performed during each season. A total of 75 and 66 chromatograms of air samples were acquired from six delineated GLAS (loafing pen, walkway, barn, silage pile, settling basin, and lagoon) of the same dairy during summer and winter, respectively. Three primary GHGs--methane (CH4), carbon dioxide (CO2), and nitrous oxide (N2O)--were identified from the dairy operation during the sampling periods. The estimated overall ERs for CH4, CO2, and N2O during the summer for this dairy were 274, 6005, and 7.96 g head(-1)day(-1), respectively. During the winter, the estimated overall CH4, CO2, and N2O ERs were 52, 7471, and 3.59 g head(-1)day(-1), respectively. The overall CH4 and N2O ERs during the summer were approximately 5.3 and 2.2 times higher than those in the winter for the free-stall dairy. These seasonal variations were likely due to fluctuations in ambient temperature, dairy manure loading rates, and manure microbial activity of GLAS. The annualized ERs for CH4, CO2, and N2O for this dairy were estimated to be 181, 6612, and 6.13 g head(-1)day(-1), respectively. Total GHG emissions calculated for this dairy with 500 cows were 2250 t of carbon dioxide equivalent (CO2e) per year. PMID:21850834

  4. Effect of Carbohydrate Sources and Levels of Cotton Seed Meal in Concentrate on Feed Intake, Nutrient Digestibility, Rumen Fermentation and Microbial Protein Synthesis in Young Dairy Bulls

    OpenAIRE

    Wanapat, M.; Anantasook, N.; Rowlinson, P.; Pilajun, R.; Gunun, P.

    2013-01-01

    The objective of this study was to investigate the effect of levels of cottonseed meal with various carbohydrate sources in concentrate on feed intake, nutrient digestibility, rumen fermentation and microbial protein synthesis in dairy bulls. Four, 6 months old dairy bulls were randomly assigned to receive four dietary treatments according to a 2×2 factorial arrangement in a 4×4 Latin square design. Factor A was carbohydrate source; cassava chip (CC) and cassava chip+rice bran in the ratio of...

  5. Assessing the Delivery of Molecules to the Mitochondrial Matrix Using Click Chemistry.

    Science.gov (United States)

    Hoogewijs, Kurt; James, Andrew M; Smith, Robin A J; Gait, Michael J; Murphy, Michael P; Lightowlers, Robert N

    2016-07-15

    Mitochondria are central to health and disease, hence there is considerable interest in developing mitochondria-targeted therapies that require the delivery of peptides or nucleic acid oligomers. However, progress has been impeded by the lack of a measure of mitochondrial import of these molecules. Here, we address this need by quantitatively detecting molecules within the mitochondrial matrix. We used a mitochondria- targeted cyclooctyne (MitoOct) that accumulates several- hundredfold in the matrix, driven by the membrane potential. There, MitoOct reacts through click chemistry with an azide on the target molecule to form a diagnostic product that can be quantified by mass spectrometry. Because the membrane potential-dependent MitoOct concentration in the matrix is essential for conjugation, we can now determine definitively whether a putative mitochondrion-targeted molecule reaches the matrix. This "ClickIn" approach will facilitate development of mitochondria-targeted therapies. PMID:27124570

  6. Engineering Cyclodextrin Clicked Chiral Stationary Phase for High-Efficiency Enantiomer Separation

    Science.gov (United States)

    Tang, Jian; Zhang, Shapopeng; Lin, Yuzhou; Zhou, Jie; Pang, Limin; Nie, Xuemei; Zhou, Baojing; Tang, Weihua

    2015-08-01

    The separation of racemic molecules is of crucial significance not only for fundamental research but also for technical application. Enantiomers remain challenging to be separated owing to their identical physical and chemical properties in achiral environments. Chromatographic techniques employing chiral stationary phases (CSPs) have been developed as powerful tools for the chiral analysis and preparation of pure enantiomers, most of which are of biological and pharmaceutical interests. Here we report our efforts in developing high-performance phenylcarbamated cyclodextrin (CD) clicked CSPs. Insights on the impact of CD functionalities in structure design are provided. High-efficiency enantioseparation of a range of aryl alcohols and flavanoids with resolution values (Rs) over 10 were demonstrated by per(3-chloro-4-methyl)phenylcarbamated CD clicked CSP. Comparison study and molecular simulations suggest the improved enantioselectivity was attributed to higher interactions energy difference between the complexes of enantiomers and CSPs with phenylcarbamated CD bearing 3-chloro and 4-methyl functionalities.

  7. Assessing the Delivery of Molecules to the Mitochondrial Matrix Using Click Chemistry

    Science.gov (United States)

    Hoogewijs, Kurt; James, Andrew M.; Smith, Robin A. J.

    2016-01-01

    Abstract Mitochondria are central to health and disease, hence there is considerable interest in developing mitochondria‐targeted therapies that require the delivery of peptides or nucleic acid oligomers. However, progress has been impeded by the lack of a measure of mitochondrial import of these molecules. Here, we address this need by quantitatively detecting molecules within the mitochondrial matrix. We used a mitochondria‐ targeted cyclooctyne (MitoOct) that accumulates several‐ hundredfold in the matrix, driven by the membrane potential. There, MitoOct reacts through click chemistry with an azide on the target molecule to form a diagnostic product that can be quantified by mass spectrometry. Because the membrane potential‐dependent MitoOct concentration in the matrix is essential for conjugation, we can now determine definitively whether a putative mitochondrion‐targeted molecule reaches the matrix. This “ClickIn” approach will facilitate development of mitochondria‐targeted therapies. PMID:27124570

  8. CuAAC click reactions for the design of multifunctional luminescent ruthenium complexes.

    Science.gov (United States)

    Zabarska, Natalia; Stumper, Anne; Rau, Sven

    2016-02-01

    CuAAC (Cu(i) catalyzed azide-alkyne cycloaddition) click chemistry has emerged as a versatile tool in the development of photoactive ruthenium complexes with multilateral potential applicability. In this contribution we discuss possible synthetic approaches towards CuAAC reactions with ruthenium(ii) polypyridine complexes and their differences with respect to possible applications. We focus on two main application possibilities of the click-coupled ruthenium assemblies. New results within the development of ruthenium based photosensitizers for the field of renewable energy supply, i.e. DSSCs (dye-sensitized solar cells) and artificial photocatalysis for the production of hydrogen, or for anticancer photodynamic therapeutic applications are reviewed. PMID:26758682

  9. A New Modular Approach to Nanoassembly: Stable and Addressable DNA Nanoconstructs via Orthogonal Click Chemistries

    KAUST Repository

    Gerrard, Simon R.

    2012-10-23

    Thermodynamic instability is a problem when assembling and purifying complex DNA nanostructures formed by hybridization alone. To address this issue, we have used photochemical fixation and orthogonal copper-free, ring-strain-promoted, click chemistry for the synthesis of dimeric, trimeric, and oligomeric modular DNA scaffolds from cyclic, double-stranded, 80-mer DNA nanoconstructs. This particular combination of orthogonal click reactions was more effective for nanoassembly than others explored. The complex nanostructures are stable to heat and denaturation agents and can therefore be purified and characterized. They are addressable in a sequence-specific manner by triplex formation, and they can be reversibly and selectively deconstructed. Nanostructures utilizing this orthogonal, chemical fixation methodology can be used as building blocks for nanomachines and functional DNA nanoarchitectures. © 2012 American Chemical Society.

  10. DNA-modified Electrodes Fabricated using Copper-Free Click Chemistry for Enhanced Protein Detection

    OpenAIRE

    Furst, Ariel L.; Hill, Michael G.; Barton, Jacqueline K.

    2013-01-01

    A method of DNA monolayer formation has been developed using copper-free click chemistry that yields enhanced surface homogeneity and enables variation in the amount of DNA assembled; extremely low-density DNA monolayers, with as little as 5% of the monolayer being DNA, have been formed. These DNA-modified electrodes (DMEs) were characterized visually, with AFM, and electrochemically, and were found to facilitate DNA-mediated reduction of a distally bound redox probe. These low-density monola...

  11. Immobilization of antimicrobial peptide IG-25 onto fluoropolymers via fluorous interactions and click chemistry

    OpenAIRE

    Santos, Catherine M.; Kumar, Amit; Kolar, Satya S.; Contreras-Caceres, Rafael; McDermott, Alison; Cai, Chengzhi

    2013-01-01

    We report a practical method for biofunctionalization of fluoropolymers based on non-covalent, fluorous interactions and click chemistry which allows incorporation of biomolecules under physiological solutions. We demonstrate the method by immobilization of an antimicrobial peptide (AMP) on fluorous thin films and fluorosilicone contact lens. The fluorous surfaces were dip-coated with fluorous-tagged oligo(ethylene) chain terminated with a reactive group, such as an alkynyl group. This simple...

  12. Copper nanoparticle heterogeneous catalytic 'click' cycloaddition confirmed by single-molecule spectroscopy

    OpenAIRE

    Decan, Matthew R; Impellizzeri, Stefania; Marín García, Mª Luisa; SCAIANO, J.

    2014-01-01

    Colloidal or heterogeneous nanocatalysts can improve the range and diversity of Cu(I)catalysed click reactions and facilitate catalyst separation and reuse. Catalysis by metal nanoparticles raises the question as to whether heterogeneous catalysts may cause homogeneous catalysis through metal ion leaching, since the catalytic process could be mediated by the particle, or by metal ions released from it. The question is critical as unwanted homogeneous processes could offset the benefits of het...

  13. A new genus and four new species of false click beetles (Coleoptera: Eucnemidae) from Southeast Asia

    OpenAIRE

    Otto, Robert L.

    2016-01-01

    A new genus and four new species of false click beetle (Coleoptera: Eucnemidae) are described. Bermilloides new genus is described from Bornean Malaysia. New species are: Calyptocerus iridis new species (Philippines), Bermilloides lumawigi new species (Malaysia), Spinifornax elongatus new species (Malaysia) and Ceratus antennatus new species (Thailand). Dorsal and ventral habitus, as possible, for each species are illustrated. Male aedeagi are illustrated for Calyptocerus iridis and Ceratu...

  14. Enhancement of TFO Triplex Formation by Conjugation with Pyrene via Click Chemistry.

    Science.gov (United States)

    Taniguchi, Yosuke; Tomizaki, Akira; Matsueda, Nozomu; Okamura, Hidenori; Sasaki, Shigeki

    2015-01-01

    This paper reports the preparation of 14-mer triplex-forming oligonucleotides (TFOs) containing a 2-O-methyl-1-β-phenyl-α-propargyl-ribose unit, which was conjugated with azide-modified molecules via a click reaction. Modification of these TFOs with pyrene assisted triplex formation, improving the stability of the triplex DNA and the anti-proliferative effects against A549 cells. PMID:26521856

  15. Dynamic combinatorial and protein-templated click chemistry in medicinal chemistry

    OpenAIRE

    Mondal, Milon

    2016-01-01

    We have highlighted throughout this thesis that fragment-based drug design (FBDD) and structure-based drug design (SBDD) still constitute a number of challenges such as the risk associated with de novo SBDD and are time-consuming as they involve synthesis and validation of the binding mode of each derivative in the fragment/hit-optimization cycle. To overcome these hurdles, we combined FBDD or de novo SBDD projects with dynamic combinatorial chemistry (DCC) or protein-templated click chemistr...

  16. Cyclooctyne-based reagents for uncatalyzed click chemistry: A computational survey

    OpenAIRE

    Chenoweth , Kimberly; Chenoweth, David; Goddard, William A. III

    2009-01-01

    With the goal of identifying alkyne-like reagents for use in click chemistry, but without Cu catalysts, we used B3LYP density function theory (DFT) to investigate the trends in activation barriers for the 1,3-dipolar cycloadditions of azides with various cyclooctyne, dibenzocyclooctyne, and azacyclooctyne compounds. Based on these trends, we find monobenzocyclooctyne-based reagents that are predicted to have dramatically improved reactivity over currently employed reagents.

  17. On the hidden curriculum of the mouse click: An anthropologically drama

    OpenAIRE

    Tobias Werler

    2008-01-01

    Any process of education is media based. But the advent of computer based media in the classroom caused a qualitative change. This new type of media serves as a bodily and cognitive extension of man. The aim of the article is to demonstrate educational consequences of these new anthropologically premises. The article discusses the structure and concept of digital communication culture as it denies the existence of spatial distance. The click option of the mouse will be framed as digital commu...

  18. Search Engines Comparison on the Basis of Session Duration and Click Hits

    Directory of Open Access Journals (Sweden)

    Rajesh Kumar Goutam

    2011-03-01

    Full Text Available The evaluation of search engines has greatly diversified in recent years. Evaluation campaigns are required to continuously re-consider their tasks and updating evaluation function in order to satisfy the users. We presented two user action dependent approaches to rank the results, namely Session duration time and Click Hits. Furthermore, we have conducted an experiment with 25 TREC queries to do comparison of five popular search engines.

  19. Multi-channel services for click and mortars ; Development of a design method

    OpenAIRE

    Simons, L.P.A.

    2006-01-01

    The rise of Internet commerce led to multiple predictions of disintermediation and the decline of physical shopping. However, a "click and mortar" approach, which combines online, offline and telephone contact, has added value for customers and for supplier profitability, as recent research confirms. Our research objective was to help organizations design Internet services for a multi-channel context. We compared several existing (service) design methods, and combined them into the "Multi-cha...

  20. Search Engines Comparison on the Basis of Session Duration and Click Hits

    OpenAIRE

    Rajesh Kumar Goutam; Sanjay Kumar Dwivedi

    2011-01-01

    The evaluation of search engines has greatly diversified in recent years. Evaluation campaigns are required to continuously re-consider their tasks and updating evaluation function in order to satisfy the users. We presented two user action dependent approaches to rank the results, namely Session duration time and Click Hits. Furthermore, we have conducted an experiment with 25 TREC queries to do comparison of five popular search engines.

  1. Interfacial thiol-ene photo-click reactions for forming multilayer hydrogels

    OpenAIRE

    Shih, Han; Fraser, Andrew K.; Lin, Chien-Chi

    2013-01-01

    Interfacial visible light-mediated thiol-ene photo-click reactions were developed for preparing step-growth hydrogels with multilayer structures. The effect of a non-cleavage type photoinitiator eosin-Y on visible light-mediated thiol-ene photopolymerization was first characterized using in situ photo-rheometry, gel fraction, and equilibrium swelling ratio. Next, spectrophotometric properties of eosin-Y in the presence of various relevant macromer species were evaluated using UV/Vis spectrome...

  2. Click and collect’; how will this affect e-tailing?

    OpenAIRE

    Roby, Helen

    2014-01-01

    This development paper will explore the findings of a set of semi-structured interviews with grocery retailers and an industry body that support these retailers. The interviews were aimed at exploring the disruptions in the form of changing business models that were occurring primarily within the grocery sector, how the grocery sector was responding to these changes and what they saw as the future developments. The paper will focus on one of these business models, the development of ‘click an...

  3. Polymer End Group Modifications and Polymer Conjugations via " Click" Chemistry Employing Microreactor Technology

    OpenAIRE

    Vandenbergh, Joke; Tura, Tiago; Baeten, Evelien; Junkers, Thomas

    2014-01-01

    This study presents the development of microreactor protocols for the successful continuous flow end group modification of atom transfer radical polymerization precursor polymers into azide end-capped materials and the subsequent copper-catalyzed azide alkyne click reactions with alkyne polymers, in flow. By using a microreactor, the reaction speed of the azidation of poly(butyl acrylate), poly(methyl acrylate), and polystyrene can be accelerated from hours to seconds and full end group conve...

  4. Click & seed” approach to the biomimetic modification of material surfaces

    Czech Academy of Sciences Publication Activity Database

    Proks, Vladimír; Jaroš, J.; Pop-Georgievski, Ognen; Kučka, Jan; Popelka, Štěpán; Dvořák, P.; Hampl, A.; Rypáček, František

    2012-01-01

    Roč. 12, č. 9 (2012), s. 1232-1242. ISSN 1616-5187 R&D Projects: GA AV ČR KJB400500904; GA ČR GAP108/11/1857; GA MŠk 1M0538 Institutional research plan: CEZ:AV0Z40500505 Keywords : biomimetic modifications * click chemistry * peptide radiolabeling Subject RIV: CD - Macromolecular Chemistry Impact factor: 3.742, year: 2012

  5. Announcement: Click It or Ticket Campaign - May 23-June 5, 2016.

    Science.gov (United States)

    2016-01-01

    Click It or Ticket is a national campaign coordinated annually by the National Highway Traffic Safety Administration to increase the proper use of seat belts. In 2014, more than 21,000 passenger vehicle occupants died in motor vehicle crashes in the United States; 49% were unrestrained at the time of the crash (1). An additional 2.4 million occupants (restrained and unrestrained) were treated in emergency departments for nonfatal crash-related injuries (2). PMID:27196941

  6. Contribution of "click chemistry" to the synthesis of antimicrobial aliphatic copolyester

    OpenAIRE

    Riva, Raphaël; Lussis, Perrine; Lenoir, Sandrine; Jérôme, Christine; Jérôme, Robert; Lecomte, Philippe

    2008-01-01

    A straightforward strategy is proposed to impart antimicrobial properties to biodegradable poly(oxepan-2-one) (poly(epsilon-caprolactone) or PCL), which is based on the grafting of pendant ammonium salts by "click" chemistry. First, statistical copolymerization of 3-chlorooxepan-2-one (alpha-chloro-epsilon-caprolactone or alpha Cl epsilon CL) with oxepan-2-one (epsilon-caprolactone or epsilon CL) was initiated by 2,2-dibutyl-2-stanna-1,3-dioxepane (DSDOP). In a second step, pendant chlorides ...

  7. Magnetic poly(N-propargylacrylamide) microspheres: preparation by precipitation polymerization and use in model click reactions

    Czech Academy of Sciences Publication Activity Database

    Macková, Hana; Proks, Vladimír; Horák, Daniel; Kučka, Jan; Trchová, Miroslava

    2011-01-01

    Roč. 49, č. 22 (2011), s. 4820-4829. ISSN 0887-624X R&D Projects: GA AV ČR KJB400500904; GA AV ČR(CZ) KAN401220801; GA ČR GAP503/10/0664 Institutional research plan: CEZ:AV0Z40500505 Keywords : click chemistry * magnetic * microspheres Subject RIV: CD - Macromolecular Chemistry Impact factor: 3.919, year: 2011

  8. Integrating Bricks with Clicks : Retailer-Level and Channel-Level Outcomes of Online-Offline Channel Integration

    OpenAIRE

    Herhausen, Dennis; Binder, Jochen; Schögel, Marcus; Herrmann, Andreas

    2014-01-01

    This research examines the impact of online-offline channel integration (OI), defined as integrating access to and knowledge about the offline channel into an online channel. Although channel integration has been acknowledged as a promising strategy for retailers, its effects on customer reactions towards retailers and across different channels remain unclear. Drawing on technology adoption research and diffusion theory, the authors conceptualize a theoretical model where perceived service qu...

  9. A Five-Level Three-Phase Cascade Multilevel Inverter Using a Single DC Source for a PM Synchronous Motor Drive

    Energy Technology Data Exchange (ETDEWEB)

    Ozpineci, Burak [ORNL; Chiasson, John N [ORNL; Tolbert, Leon M [ORNL

    2007-01-01

    The interest here is in using a single DC power source to construct a 3-phase 5-level cascade multilevel inverter to be used as a drive for a PM traction motor. The 5-level inverter consists of a standard 3-leg inverter (one leg for each phase) and an H-bridge in series with each inverter leg, which use a capacitor as a DC source. It is shown that one can simultaneously maintain the regulation of the capacitor voltage while achieving an output voltage waveform which is 25% higher than that obtained using a standard 3-leg inverter by itself.

  10. Click chemistry for [99mTc(CO)3] labeling of Lys3-bombesin

    International Nuclear Information System (INIS)

    99mTc-HYNIC labeled Lys3-bombesin has shown specific binding to gastrin-releasing peptide receptors (GRP-r) over-expressed in cancer cells. Click chemistry offers an innovative functionalization strategy for biomolecules such as bombesin. The aim of this research was to apply a click chemistry approach for [99mTc(CO)3] labeling of Lys3-bombesin and to compare the in vitro MCF7 breast cancer cell uptake and biodistribution profile in mice with that of 99mTc-EDDA/HYNIC-Lys3-bombesin. The results suggest a higher lipophilicity for 99mTc(CO)3-triazole-Lys3-bombesin which explains its higher in vivo hepatobiliary elimination. Pancreas-to-blood ratio for 99mTc(CO)3-triazole-Lys3-bombesin was 4.46 at 3 h and both bombesin radiopharmaceuticals showed specific recognition for GRP receptors in MCF7 cancer cells. Click chemistry is a reliable approach for [99mTc(CO)3] labeling of Lys3-bombesin.

  11. Conjugating folate on superparamagnetic Fe3O4@Au nanoparticles using click chemistry

    International Nuclear Information System (INIS)

    Gold-coated magnetic core@shell nanoparticles, which exhibit magneto-optical properties, not only enhance the chemical stability of core and biocompatibility of surface, but also provide a combination of multimodal imaging and therapeutics. The conjugation of these tiny nanoparticles with specific biomolecules allows researchers to target the desired location. In this paper, superparamagnetic Fe3O4@Au nanoparticles were synthesized and functionalized with the azide group on the surface by formation of self-assembled monolayers. Folate (FA) molecules, non-immunogenic target ligands for cancer cells, are conjugated with alkyne and then immobilized on the azide-terminated Fe3O4@Au nanoparticles through copper(I)-catalyzed azide-alkyne cycloaddition (click reaction). Myelogenous leukemia K562 cells were used as a folate receptor (FR) model, which can be targeted and extracted by magnetic field after interaction with the Fe3O4@Au–FA nanoparticles. - Graphical abstract: Self-assembled azide-terminated group on superparamagnetic Fe3O4@Au nanoparticles followed by click reaction with alkyne-functionalized folate, allowing the nanoparticles target folate receptor of cancer cells. - Highlights: • Azidoundecanethiol was coated on the superparamagnetic Fe3O4@Au nanoparticles by forming self-assembled monolayers. • Alkyne-terminated folate was synthesized from a reaction between the amine and the carboxylic acid. • Conjugation of Fe3O4@Au nanoparticles with folate was made by copper-catalyzed azide-alkyne cycloaddition click chemistry

  12. Methoxypropylamino β-cyclodextrin clicked AC regioisomer for enantioseparations in capillary electrophoresis

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Jie; Wang, Yiying; Liu, Yun; Tang, Jian; Tang, Weihua, E-mail: whtang@mail.njust.edu.cn

    2015-04-08

    Highlights: In this paper, we demonstrate: • The click synthesis of a AC regioisomer cationic cyclodextrin (CD) as chiral selector. • The good enantioselectivities (chiral resolution over 5) for acidic racemates. • The strong chiral recognition of new CD by NMR study. • Baseline enantioseparation of some acidic racemates at CD of 0.5 mM. - Abstract: In this work, a novel methoxypropylamino β-cyclodextrin (β-CD) clicked AC regioisomer, 6{sup A}-4-hydroxyethyl-1,2,3-triazolyl-6{sup C}-3-methoxypropylamino β-cyclodextrin (HETz-MPrAMCD), was synthesized via nucleophilic addition and click chemistry. The chiral separation ability of this AC regioisomer cationic CD was evaluated toward 7 ampholytic and 13 acidic racemates by capillary electrophoresis. Dependence of enantioselectivity and resolution on buffer pH (5.5–8.0) and chiral selector concentration (0.5–7.5 mM) was investigated. Enantioselectivities (α ≥ 1.05) could be achieved for most analytes under optimal conditions except dansyl-DL-noreleucine and dansyl-DL-serine. The highest resolutions for 2-chloromandelic acid p-hydroxymandelic acid were 15.6 and 9.7 respectively. The inclusion complexation between HETz-MPrAMCD and each 3-phenyllactic acid enantiomer was also revealed with nuclear magnetic resonance study.

  13. Versatility of Alkyne-Modified Poly(Glycidyl Methacrylate) Layers for Click Reactions

    International Nuclear Information System (INIS)

    Functional soft interfaces are of interest for a variety of technologies. We describe three methods for preparing substrates with alkyne groups, which show versatility for 'click' chemistry reactions. Two of the methods have the same root: formation of thin, covalently attached, reactive interfacial layers of poly(glycidyl methacrylate) (PGMA) via spin coating onto silicon wafers followed by reactive modification with either propargylamine or 5-hexynoic acid. The amine or the carboxylic acid moieties react with the epoxy groups of PGMA, creating interfacial polymer layers decorated with alkyne groups. The third method consists of using copolymers comprising glycidyl methacrylate and propargyl methacrylate (pGP). The pGP copolymers are spin coated and covalently attached on silicon wafers. For each method, we investigate the factors that control film thickness and content of alkyne groups using ellipsometry, and study the nanophase structure of the films using neutron reflectometry. Azide-terminated polymers of methacrylic acid and 2-vinyl-4,4-dimethylazlactone synthesized via reversible addition-fragmentation chain transfer polymerization were attached to the alkyne-modified substrates using 'click' chemistry, and grafting densities in the range of 0.007-0.95 chains nm-2 were attained. The maximum density of alkyne groups attained by functionalization of PGMA with propargylamine or 5-hexynoic acid was approximately 2 alkynes nm-3. The alkyne content obtained by the three decorating approaches was sufficiently high that it was not the limiting factor for the click reaction of azide-capped polymers.

  14. Methoxypropylamino β-cyclodextrin clicked AC regioisomer for enantioseparations in capillary electrophoresis

    International Nuclear Information System (INIS)

    Highlights: In this paper, we demonstrate: • The click synthesis of a AC regioisomer cationic cyclodextrin (CD) as chiral selector. • The good enantioselectivities (chiral resolution over 5) for acidic racemates. • The strong chiral recognition of new CD by NMR study. • Baseline enantioseparation of some acidic racemates at CD of 0.5 mM. - Abstract: In this work, a novel methoxypropylamino β-cyclodextrin (β-CD) clicked AC regioisomer, 6A-4-hydroxyethyl-1,2,3-triazolyl-6C-3-methoxypropylamino β-cyclodextrin (HETz-MPrAMCD), was synthesized via nucleophilic addition and click chemistry. The chiral separation ability of this AC regioisomer cationic CD was evaluated toward 7 ampholytic and 13 acidic racemates by capillary electrophoresis. Dependence of enantioselectivity and resolution on buffer pH (5.5–8.0) and chiral selector concentration (0.5–7.5 mM) was investigated. Enantioselectivities (α ≥ 1.05) could be achieved for most analytes under optimal conditions except dansyl-DL-noreleucine and dansyl-DL-serine. The highest resolutions for 2-chloromandelic acid p-hydroxymandelic acid were 15.6 and 9.7 respectively. The inclusion complexation between HETz-MPrAMCD and each 3-phenyllactic acid enantiomer was also revealed with nuclear magnetic resonance study

  15. Clicks, whistles and pulses: Passive and active signal use in dolphin communication

    Science.gov (United States)

    Herzing, Denise L.

    2014-12-01

    The search for signals out of noise is a problem not only with radio signals from the sky but in the study of animal communication. Dolphins use multiple modalities to communicate including body postures, touch, vision, and most elaborately sound. Like SETI radio signal searches, dolphin sound analysis includes the detection, recognition, analysis, and interpretation of signals. Dolphins use both passive listening and active production to communicate. Dolphins use three main types of acoustic signals: frequency modulated whistles (narrowband with harmonics), echolocation (broadband clicks) and burst pulsed sounds (packets of closely spaced broadband clicks). Dolphin sound analysis has focused on frequency-modulated whistles, yet the most commonly used signals are burst-pulsed sounds which, due to their graded and overlapping nature and bimodal inter-click interval (ICI) rates are hard to categorize. We will look at: 1) the mechanism of sound production and categories of sound types, 2) sound analysis techniques and information content, and 3) examples of lessons learned in the study of dolphin acoustics. The goal of this paper is to provide perspective on how animal communication studies might provide insight to both passive and active SETI in the larger context of searching for life signatures.

  16. Effect of improved operating practices in collective dose reduction during fabrication of kilo curie level of sealed sources

    International Nuclear Information System (INIS)

    Since last 3 decades, fabrication of 60Co and 192Ir sealed sources in hot cells at Radiological Laboratories is being carried out for their widespread applications in industry and medicine. Many improvements in operating practices and modification in design of source capsules have been implemented since then with respect to radiation safety aspects. The radiological data generated during fabrication of sealed sources have been served as guidelines for designing of the new upcoming hot cell facilities. The radiological data indicates the collective dose reduction by a factor of ∼2 as compared with earlier values of 1999. In this paper, efforts have been made to analyze data keeping in focus the critical groups and jobs involved in source fabrication work. (author)

  17. One-Click Data Analysis Software for Science Operations

    Science.gov (United States)

    Navarro, Vicente

    2015-12-01

    One of the important activities of ESA Science Operations Centre is to provide Data Analysis Software (DAS) to enable users and scientists to process data further to higher levels. During operations and post-operations, Data Analysis Software (DAS) is fully maintained and updated for new OS and library releases. Nonetheless, once a Mission goes into the "legacy" phase, there are very limited funds and long-term preservation becomes more and more difficult. Building on Virtual Machine (VM), Cloud computing and Software as a Service (SaaS) technologies, this project has aimed at providing long-term preservation of Data Analysis Software for the following missions: - PIA for ISO (1995) - SAS for XMM-Newton (1999) - Hipe for Herschel (2009) - EXIA for EXOSAT (1983) Following goals have guided the architecture: - Support for all operations, post-operations and archive/legacy phases. - Support for local (user's computer) and cloud environments (ESAC-Cloud, Amazon - AWS). - Support for expert users, requiring full capabilities. - Provision of a simple web-based interface. This talk describes the architecture, challenges, results and lessons learnt gathered in this project.

  18. Peptide-Functionalized Click Hydrogels with Independently Tunable Mechanics and Chemical Functionality for 3D Cell Culture

    OpenAIRE

    DeForest, Cole A; Sims, Evan A.; Anseth, Kristi S.

    2010-01-01

    Click chemistry offers highly selective and orthogonal reactions that proceed rapidly and under a variety of mild conditions with the opportunity to create highly defined and multifunctional materials. This work illustrates a strategy where step-growth networks are formed rapidly via a copper-free, azide−alkyne click chemistry between tetrafunctional poly(ethylene glycol) molecules and difunctionalized synthetic polypeptides. The molecular weight of the polymer precursors (10, 15, or 20 kDa P...

  19. Dual-switchable surfaces between hydrophobic and superhydrophobic fabricated by the combination of click chemistry and RAFT

    OpenAIRE

    Han, M S; Zhang, X. Y.; Li, L.; Peng, C; Bao, L.; E. C. Ou; Xiong, Y Q; Xu, W. J.

    2014-01-01

    A dual-switchable surface between hydrophobic and superhydrophobic has been fabricated successfully by combining reversible addition-fragmentation chain transfer polymerization (RAFT) polymeric technology and thiol-NCO click chemistry. Well-defined block copolymer, poly(7-(6-(acryloyloxy) hexyloxy) coumarin)-b-poly(N-Isopropylacryl amide), was synthesized by RAFT, and then the block copolymer was grafted onto the surface of SiO2 modified by toluene disocynate (TDI) via thiol-NCO click chemist...

  20. In situ visualization of newly synthesized proteins in environmental microbes using amino acid tagging and click chemistry

    OpenAIRE

    Hatzenpichler, Roland; Scheller, Silvan; Tavormina, Patricia L.; Babin, Brett M; Tirrell, David A.; Orphan, Victoria J.

    2014-01-01

    Here we describe the application of a new click chemistry method for fluorescent tracking of protein synthesis in individual microorganisms within environmental samples. This technique, termed bioorthogonal non-canonical amino acid tagging (BONCAT), is based on the in vivo incorporation of the non-canonical amino acid L-azidohomoalanine (AHA), a surrogate for l -methionine, followed by fluorescent labelling of AHA-containing cellular proteins by azide-alkyne click chemistry. BONCAT was evalua...

  1. The energy ratio mapping algorithm: a tool to improve the energy-based detection of odontocete echolocation clicks.

    Science.gov (United States)

    Klinck, Holger; Mellinger, David K

    2011-04-01

    The energy ratio mapping algorithm (ERMA) was developed to improve the performance of energy-based detection of odontocete echolocation clicks, especially for application in environments with limited computational power and energy such as acoustic gliders. ERMA systematically evaluates many frequency bands for energy ratio-based detection of echolocation clicks produced by a target species in the presence of the species mix in a given geographic area. To evaluate the performance of ERMA, a Teager-Kaiser energy operator was applied to the series of energy ratios as derived by ERMA. A noise-adaptive threshold was then applied to the Teager-Kaiser function to identify clicks in data sets. The method was tested for detecting clicks of Blainville's beaked whales while rejecting echolocation clicks of Risso's dolphins and pilot whales. Results showed that the ERMA-based detector correctly identified 81.6% of the beaked whale clicks in an extended evaluation data set. Average false-positive detection rate was 6.3% (3.4% for Risso's dolphins and 2.9% for pilot whales). PMID:21476637

  2. Off-axis effects on the multipulse structure of sperm whale usual clicks with implications for sound production

    Science.gov (United States)

    Zimmer, Walter M. X.; Madsen, Peter T.; Teloni, Valeria; Johnson, Mark P.; Tyack, Peter L.

    2005-11-01

    Sperm whales (Physeter macrocephalus) produce multipulsed clicks with their hypertrophied nasal complex. The currently accepted view of the sound generation process is based on the click structure measured directly in front of, or behind, the whale where regular interpulse intervals (IPIs) are found between successive pulses in the click. Most sperm whales, however, are recorded with the whale in an unknown orientation with respect to the hydrophone where the multipulse structure and the IPI do not conform to a regular pulse pattern. By combining far-field recordings of usual clicks with acoustic and orientation information measured by a tag on the clicking whale, we analyzed clicks from known aspects to the whale. We show that a geometric model based on the bent horn theory for sound production can explain the varying off-axis multipulse structure. Some of the sound energy that is reflected off the frontal sac radiates directly into the water creating an intermediate pulse p1/2 seen in off-axis recordings. The powerful p1 sonar pulse exits the front of the junk as predicted by the bent-horn model, showing that the junk of the sperm whale nasal complex is both anatomically and functionally homologous to the melon of smaller toothed whales.

  3. A 7-Level Single DC Source Cascaded H-Bridge Multilevel Inverter with a Modified DTC Scheme for Induction Motor-Based Electric Vehicle Propulsion

    Directory of Open Access Journals (Sweden)

    Farid Khoucha

    2013-01-01

    Full Text Available This paper presents a new hybrid cascaded H-bridge multilevel inverter motor drive DTC scheme for electric vehicles where each phase of the inverter can be implemented using a single DC source. Traditionally, each phase of the inverter requires DC source for output voltage levels. In this paper, a scheme is proposed that allows the use of a single DC source as the first DC source which would be available from batteries or fuel cells, with the remaining ( DC sources being capacitors. This scheme can simultaneously maintain the capacitors of DC voltage level and produce a nearly sinusoidal output voltage due to its high number of output levels. In this context, high performances and efficient torque and flux control are obtained, enabling a DTC solution for hybrid multilevel inverter powered induction motor drives intended for electric vehicle propulsion. Simulations and experiments show that the proposed multilevel inverter and control scheme are effective and very attractive for embedded systems such as automotive applications.

  4. Xenobiotic organic micropollutants in urban wastewater : levels, distribution patterns and the impact of advanced treatment technologies on their presence in wastewater from different sources

    OpenAIRE

    Kraus, Uta R.

    2014-01-01

    This study investigated the occurrence of 52 xenobiotic micropollutants – pharmaceuticals, metabolites, transformation products, and organophosphorus compounds (OPs) – in hospital and municipal wastewater. It aimed to characterise the xenobiotic fingerprint in raw wastewater from different sources and the impact of different advanced treatment technologies on concentration levels and distribution patterns of xenobiotic micropollutants. Thus, temporal concentration profiles of the influent and...

  5. Low-level waste shallow land burial source term container breach and waste form leaching model development

    International Nuclear Information System (INIS)

    A general computer model has been developed to predict the release and transport (i.e. source term) of radionuclides from shallow land burial facilities. This model predicts the processes of unsaturated water flow, metallic container degradation, leaching of radionuclides from the waste form, and their movement away from the waste form. This paper discusses model development work for the container degradation and leaching aspects of the source term model. Application of these models and the sensitivity of release rates to model parameters, e.g. diffusion coefficients, corrosion rates, etc., are also discussed. 14 refs., 2 figs

  6. Yeast (different sources and levels) as protein source in diets of reared piglets: effects on protein digestibility and N-metabolism.

    Science.gov (United States)

    Spark, M; Paschertz, H; Kamphues, J

    2005-01-01

    The aim of this study was to examine the feeding value of different yeasts as a substitute for soya bean meal, the main protein source in diets of weaned piglets. Tested two yeasts were already available on the market, Saccharomyces cerevisiae and Kluyveromyces lactis (beer and milk yeast), which replaced 40% of the soya bean meal in the diets. Furthermore, a yeast (Kluyveromyces fragilis) grown on whey, a side-product of cheese production, was used in increasing concentrations in the diets, so that increasing amounts of the soya bean meal (20%, 40% and 60%) could be replaced. As proved in these experiments, a replacement of 60% of the soya protein with whey yeast protein had positive effects on the performances (daily weight gain) and on the N-metabolism and did not have negative effects on the health or the faeces consistency. The whey yeast stands out because of its high protein quality (N-digestibility and N-retention). Furthermore, the replacement of soya bean meal with highly digestible yeasts is welcomed under the aspect of animal health, because of the reduction of anti-nutritive soya components (stachyose, glycinin) in diets of weaned piglets. The controlled production conditions of the yeasts result in a high feed safety; in addition, the yeast as an end-of-pipe-product is a resource conserving and valuable feed. A main stimulus for the use of yeasts, however, in a food production controlled by economic standpoints, is their price and the costs of other competing feeds. PMID:15787992

  7. Single "click" synthesis of a mixed-mode silica sorbent and application in matrix solid-phase dispersion extraction of β-agonists from porcine liver.

    Science.gov (United States)

    Zhu, Yuling; Yang, Siwen; Chen, Gang; Xing, Jun

    2014-08-01

    A single "click" strategy is proposed for the preparation of a reversed-phase/weak cation-exchange mixed-mode silica-based sorbent (silica-WCX). Upon this strategy, both 1-dodecyne and 5-hexynoic acid were simultaneously immobilized onto azide-silica in varied ratio via Cu (I)-catalyzed azide-alkyne cycloaddition click reaction. The chemical compositions of silica-WCXs were characterized by elemental analysis, acid-base titration and Fourier transform-infrared spectroscopy. The results indicated that the actual mole ratio of n-dodecyl to carboxylic group on the sorbent is almost the same as the reactant ratio of 1-dodecyne to 5-hexynoic acid, and the repeatability of synthesis method is good. After that, two β-agonists, clenbuterol and ractopamine, were selected as model drug residues to evaluate the applicability of silica-WCX in matrix solid-phase dispersion extraction for the determination of basic drug residues in porcine liver by HPLC/UV. In comparison with some commercial sorbents, silica-WCX exhibited higher recoveries and better purification capability. Under the optimized conditions, linearity ranges were between 0.04 and 8.0μg/g for both analytes with coefficients of determination (R(2)) higher than 0.9997. The average recoveries at three spiked levels ranged from 92.5% to 105.0% with RSDs less than 6.6%. PMID:24929910

  8. A Self-Adaptive Dynamic Recognition Model for Fatigue Driving Based on Multi-Source Information and Two Levels of Fusion.

    Science.gov (United States)

    Sun, Wei; Zhang, Xiaorui; Peeta, Srinivas; He, Xiaozheng; Li, Yongfu; Zhu, Senlai

    2015-01-01

    To improve the effectiveness and robustness of fatigue driving recognition, a self-adaptive dynamic recognition model is proposed that incorporates information from multiple sources and involves two sequential levels of fusion, constructed at the feature level and the decision level. Compared with existing models, the proposed model introduces a dynamic basic probability assignment (BPA) to the decision-level fusion such that the weight of each feature source can change dynamically with the real-time fatigue feature measurements. Further, the proposed model can combine the fatigue state at the previous time step in the decision-level fusion to improve the robustness of the fatigue driving recognition. An improved correction strategy of the BPA is also proposed to accommodate the decision conflict caused by external disturbances. Results from field experiments demonstrate that the effectiveness and robustness of the proposed model are better than those of models based on a single fatigue feature and/or single-source information fusion, especially when the most effective fatigue features are used in the proposed model. PMID:26393615

  9. A Self-Adaptive Dynamic Recognition Model for Fatigue Driving Based on Multi-Source Information and Two Levels of Fusion

    Directory of Open Access Journals (Sweden)

    Wei Sun

    2015-09-01

    Full Text Available To improve the effectiveness and robustness of fatigue driving recognition, a self-adaptive dynamic recognition model is proposed that incorporates information from multiple sources and involves two sequential levels of fusion, constructed at the feature level and the decision level. Compared with existing models, the proposed model introduces a dynamic basic probability assignment (BPA to the decision-level fusion such that the weight of each feature source can change dynamically with the real-time fatigue feature measurements. Further, the proposed model can combine the fatigue state at the previous time step in the decision-level fusion to improve the robustness of the fatigue driving recognition. An improved correction strategy of the BPA is also proposed to accommodate the decision conflict caused by external disturbances. Results from field experiments demonstrate that the effectiveness and robustness of the proposed model are better than those of models based on a single fatigue feature and/or single-source information fusion, especially when the most effective fatigue features are used in the proposed model.

  10. Multiobjective optimization of cluster-scale urban water systems investigating alternative water sources and level of decentralization

    Science.gov (United States)

    Newman, J. P.; Dandy, G. C.; Maier, H. R.

    2014-10-01

    In many regions, conventional water supplies are unable to meet projected consumer demand. Consequently, interest has arisen in integrated urban water systems, which involve the reclamation or harvesting of alternative, localized water sources. However, this makes the planning and design of water infrastructure more difficult, as multiple objectives need to be considered, water sources need to be selected from a number of alternatives, and end uses of these sources need to be specified. In addition, the scale at which each treatment, collection, and distribution network should operate needs to be investigated. In order to deal with this complexity, a framework for planning and designing water infrastructure taking into account integrated urban water management principles is presented in this paper and applied to a rural greenfield development. Various options for water supply, and the scale at which they operate were investigated in order to determine the life-cycle trade-offs between water savings, cost, and GHG emissions as calculated from models calibrated using Australian data. The decision space includes the choice of water sources, storage tanks, treatment facilities, and pipes for water conveyance. For each water system analyzed, infrastructure components were sized using multiobjective genetic algorithms. The results indicate that local water sources are competitive in terms of cost and GHG emissions, and can reduce demand on the potable system by as much as 54%. Economies of scale in treatment dominated the diseconomies of scale in collection and distribution of water. Therefore, water systems that connect large clusters of households tend to be more cost efficient and have lower GHG emissions. In addition, water systems that recycle wastewater tended to perform better than systems that captured roof-runoff. Through these results, the framework was shown to be effective at identifying near optimal trade-offs between competing objectives, thereby enabling

  11. Tetrathiafulvalene mono- and bis-1,2,3-triazole precursors by click chemistry: structural diversity and reactivity.

    Science.gov (United States)

    Biet, Thomas; Avarvari, Narcis

    2014-05-28

    The donor ortho-dimethyl-TTF-(N-n-Bu-1,2,3-triazole) 1,5-isomer has been synthesized by click chemistry following a ruthenium-catalyzed azide-alkyne cycloaddition procedure. The single crystal X-ray analysis showed a planar conformation between the TTF and triazole units and a set of intermolecular interactions at the supramolecular level in the solid state. The same procedure allowed the preparation of the corresponding ortho-dimethyl-TTF-bis(triazole) which was also structurally characterized. Because of the steric hindrance, the triazole units are no longer planar with the TTF backbone. The reactivity of the triazole ring has been investigated in protonation and alkylation reactions, monitored by UV-visible spectroscopy, which clearly showed the red shift of the intramolecular charge transfer band. A TTF-methyl-triazolium salt has been isolated and analyzed by single crystal X-ray analysis. All of the TTF-triazoles and triazolium salts are valuable precursors for radical cation salts due to their oxidation potentials and variety of possible intermolecular interactions. PMID:24682102

  12. Canadian and U.S. sources impacting the mercury levels in fine atmospheric particulate material across New York state

    Energy Technology Data Exchange (ETDEWEB)

    Olmez, I.; Ames, M.R.; Gullu, G. [Massachusetts Inst. of Tech., Cambridge, MA (United States). Nuclear Reactor Lab.

    1998-10-15

    An extensive atmospheric sampling and analysis program has been completed in order to identify and apportion the sources of mercury associated with fine atmospheric particulate material. Samples of fine atmospheric particulate material were collected daily, at five remote sites in New York State, over a period of 2 years. The trace element composition of 1200 of these samples was determined by Instrumental Neutron Activation Analysis. Results of both meteorological and statistical analyses of the data indicate that approximately 55% of the fine particulate mercury originated from smelters in Ontario and Quebec, and 25% originated from a mixture of regional sources in the Midwestern United States. A decline in the average measured particulate Hg concentration, beginning in February 1993, has been attributed to reduced emissions from one or more of the major Canadian smelters.

  13. An icy energy source. Bartering gases below sea level; Eisige Energiequelle. Gase-Tauschhandel unter dem Meeresspiegel

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2010-07-01

    Warmer oceans aren't just making the polar ice caps melt. Methane ice - found in large amounts in the seabed - is also melting, threatening the climate. Linde is working together with partners to develop technology designed to safely recover the greenhouse gas from its submarine sources for use as energy, while simultaneously storing the CO{sub 2} produced by power plants. (orig.)

  14. Effect of foliar application of different Fe levels and sources on growth and concentration of some nutrients in sorghum

    OpenAIRE

    L. Jokar; A. Ronaghi

    2015-01-01

    One of the fast responding methods of plants to fertilizer application is foliar application, which saves fertilizer consumption too. Foliar application of micronutrients is a useful method, especially when roots are unable to absorb necessary elements from soil. The amount of available iron (Fe) in calcareous soils, with high pH, is low for sensitive plants, such as sorghum, to Fe deficiency. To compare the effect of foliar application of different Fe sources on growth traits, concentration ...

  15. Heavy metals in soils from a typical county in Shanxi Province, China: Levels, sources and spatial distribution.

    Science.gov (United States)

    Pan, Li-bo; Ma, Jin; Wang, Xian-liang; Hou, Hong

    2016-04-01

    The concentrations of As, Cd, Cr, Cu, Pb, Ni, Zn, and Hg in 128 surface soil samples from Xiangfen County, Shanxi Province, China were measured. The concentrations of these eight heavy metals were lower than the critical values in the national soil quality standard. However, these concentrations were found to be slightly higher than their background values in soils in Shanxi Province, indicating enrichment of these metals in soils in Xiangfen County, especially for Hg and Cd. Principal component analysis coupled with cluster analysis was used to analyze the data and identify possible sources of these heavy metals; the results showed that the eight heavy metals in soils from Xiangfen County came from three different sources. Lead, Cd, Cu and Zn mainly arose from agricultural practices and vehicle emissions. Arsenic and Ni arose mainly from parent materials. Industrial practices were the main sources of Cr and Hg. The spatial distribution of the heavy metals varied greatly, and was closely correlated to local anthropogenic activities. This study will be helpful not only for improving local soil environmental quality but will also provide a basis for effectively targeting policies to protect soils from long-term heavy metal accumulation. PMID:26807946

  16. Effects of different Fe levels from Fe-nano-chelate and Fe-EDDHA sources on growth and some nutrients concentrations in cowpea in a calcareous soil

    Directory of Open Access Journals (Sweden)

    L. Jokar

    2015-08-01

    Full Text Available To evaluate the effects of different levels of iron (Fe (from Fe-nano-chelate and Fe-EDDHA sources on growth parameters, concentration and absorption of Fe and some nutrients in cowpea (Vigna unguiculata in a calcareous soil, a greenhouse experiment was conducted based on completely randomized design with three replications. Treatments consisted of four levels of Fe (0, 0.135, 0.270 and 0.405 mg Fe per kg soil as Fe-nano-chelate or Fe-EDDHA. The studied soil (Fine-loamy, carbonatic, thermic, Typic Calcixerepts had a loam texture with low available Fe content. Results showed that application of both Fe fertilizers increased shoot dry-matter yield, root dry matter yield, number of pods per plant, weight of pods and seeds per plant, grain weight per pot, shoot Fe concentration and Fe uptake by cowpea as compared to control treatment. Some of the evaluated growth parameters at all levels of Fe from Fe-nano-chelate source were higher than the Fe-EDDHA source and some were the same and had no significant difference. Application of both Fe-nano-chelate and Fe-EDDHA decreased phosphorus and manganese concentrations in shoots as compared to control treatment. Concentration of zinc and cooper in shoots was not significantly affected by the Fe level. In conclusion, lower rates of Fe-nano-chelate were required, as compared to Fe-EDDHA, to alleviate iron deficiency in cowpea grown in calcareous soils.

  17. Continued Maturation of the Click-Evoked Auditory Brainstem Response in Preschoolers

    Science.gov (United States)

    Spitzer, Emily; White-Schwoch, Travis; Carr, Kali Woodruff; Skoe, Erika; Kraus, Nina

    2016-01-01

    Background Click-evoked auditory brainstem responses (ABRs) are a valuable tool for probing auditory system function and development. Although it has long been thought that the human auditory brainstem is fully mature by age 2 yr, recent evidence indicates a prolonged developmental trajectory. Purpose The purpose of this study was to determine the time course of ABR maturation in a preschool population and fill a gap in the knowledge of development. Research Design Using a cross-sectional design, we investigated the effect of age on absolute latencies, interwave latencies, and amplitudes (waves I, III, V) of the click-evoked ABR. Study Sample A total of 71 preschoolers (ages 3.12–4.99 yr) participated in the study. All had normal peripheral auditory function and IQ. Data Collection and Analysis ABRs to a rarefaction click stimulus presented at 31/sec and 80 dB SPL (73 dB nHL) were recorded monaurally using clinically-standard recording and filtering procedures while the participant sat watching a movie. Absolute latencies, interwave latencies, and amplitudes were then correlated to age. Results Developmental changes were restricted to absolute latencies. Wave V latency decreased significantly with age, whereas wave I and III latencies remained stable, even in this restricted age range. Conclusions The ABR does not remain static after age 2 yr, as seen by a systematic decrease in wave V latency between ages 3 and 5 yr. This finding suggests that the human brainstem has a continued developmental time course during the preschool years. Latency changes in the age 3–5 yr range should be considered when using ABRs as a metric of hearing health. PMID:25597458

  18. Versatility of Alkyne-Modified Poly(Glycidyl Methacrylate) Layers for Click Reactions

    Energy Technology Data Exchange (ETDEWEB)

    Soto-Cantu, Dr. Erick [University of Tennessee, Knoxville (UTK); Lokitz, Bradley S [ORNL; Hinestrosa Salazar, Juan Pablo [Clemson University; Deodhar, Chaitra [University of Tennessee, Knoxville (UTK); Messman, Jamie M [ORNL; Ankner, John Francis [ORNL; Kilbey, II, S Michael [ORNL

    2011-01-01

    Functional soft interfaces are of interest for a variety of technologies. We describe three methods for preparing substrates with alkyne groups, which show versatility for 'click' chemistry reactions. Two of the methods have the same root: formation of thin, covalently attached, reactive interfacial layers of poly(glycidyl methacrylate) (PGMA) via spin coating onto silicon wafers followed by reactive modification with either propargylamine or 5-hexynoic acid. The amine or the carboxylic acid moieties react with the epoxy groups of PGMA, creating interfacial polymer layers decorated with alkyne groups. The third method consists of using copolymers comprising glycidyl methacrylate and propargyl methacrylate (pGP). The pGP copolymers are spin coated and covalently attached on silicon wafers. For each method, we investigate the factors that control film thickness and content of alkyne groups using ellipsometry, and study the nanophase structure of the films using neutron reflectometry. Azide-terminated polymers of methacrylic acid and 2-vinyl-4,4-dimethylazlactone synthesized via reversible addition-fragmentation chain transfer polymerization were attached to the alkyne-modified substrates using 'click' chemistry, and grafting densities in the range of 0.007-0.95 chains nm{sup -2} were attained. The maximum density of alkyne groups attained by functionalization of PGMA with propargylamine or 5-hexynoic acid was approximately 2 alkynes nm{sup -3}. The alkyne content obtained by the three decorating approaches was sufficiently high that it was not the limiting factor for the click reaction of azide-capped polymers.

  19. High-yield clicking and dissociation of doxorubicin nanoclusters exhibiting differential cellular uptakes and imaging.

    Science.gov (United States)

    Kim, Hye Sung; Yoon, Sujin; Son, Young Ju; Park, Yeonju; Jung, Young Mee; Yoo, Hyuk Sang

    2015-11-10

    Gold nanoparticles (AuNPs) and quantum dots (Qdots) were clicked into doxorubicin nanoclusters that showed enzyme-dependent dissociation behaviors for differential cellular uptakes and imaging. The AuNPs were co-functionalized with doxorubicin (DOX) and azide-terminated polymer (DOX/azide@AuNP), while an enzyme-cleavable peptide and alkyne-terminated polymer were sequentially conjugated on Qdot surface (Alkyne-MMP@Qdot). Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, and fluorescence imaging detected the azide and alkyne groups on DOX/azide@AuNP and Alkyne-MMP@Qdot, respectively, and the click-reactivity was also confirmed. In the presence of the catalyst, two nanoparticles were clicked to doxorubicin nanoclusters, which increased the volume of the particles ca. 343-fold within 30min. Upon matrix metalloproteinase-2 (MMP-2) digestion, the nanoclusters were clearly dissociated into smaller particles, and the fluorescence of the quenched Qdot was also recovered, which suggests that the nanoclusters respond to MMP-2 concentrations and can thus be employed for cancer imaging. Confocal microscopy and an elemental analysis of the cancer cells revealed that the cellular uptakes of doxorubicin nanoclusters significantly increased at higher MMP-2 concentrations, and doxorubicin could also be cleaved for anti-cancer effects. In vivo and in vitro cytotoxicity assay accordingly showed that the cytotoxicity of doxorubicin nanoclusters against cancer cells increased in MMP-2-rich environments such as tumor site. Thus, these nanoclusters containing DOX/azide@AuNP and Alkyne-MMP@Qdot are expected to be multifunctional carriers for targeted anti-cancer treatments and imaging. PMID:26315815

  20. Evaluating and Optimizing Online Advertising: Forget the Click, but There Are Good Proxies.

    Science.gov (United States)

    Dalessandro, Brian; Hook, Rod; Perlich, Claudia; Provost, Foster

    2015-06-01

    Online systems promise to improve advertisement targeting via the massive and detailed data available. However, there often is too few data on exactly the outcome of interest, such as purchases, for accurate campaign evaluation and optimization (due to low conversion rates, cold start periods, lack of instrumentation of offline purchases, and long purchase cycles). This paper presents a detailed treatment of proxy modeling, which is based on the identification of a suitable alternative (proxy) target variable when data on the true objective is in short supply (or even completely nonexistent). The paper has a two-fold contribution. First, the potential of proxy modeling is demonstrated clearly, based on a massive-scale experiment across 58 real online advertising campaigns. Second, we assess the value of different specific proxies for evaluating and optimizing online display advertising, showing striking results. The results include bad news and good news. The most commonly cited and used proxy is a click on an ad. The bad news is that across a large number of campaigns, clicks are not good proxies for evaluation or for optimization: clickers do not resemble buyers. The good news is that an alternative sort of proxy performs remarkably well: observed visits to the brand's website. Specifically, predictive models built based on brand site visits-which are much more common than purchases-do a remarkably good job of predicting which browsers will make a purchase. The practical bottom line: evaluating and optimizing campaigns using clicks seems wrongheaded; however, there is an easy and attractive alternative-use a well-chosen site-visit proxy instead. PMID:27447433

  1. PBDEs and other POPs in urban birds of prey partly explained by trophic level and carbon source

    Energy Technology Data Exchange (ETDEWEB)

    Elliott, John E. [Environment Canada, Science & Technology Branch, Pacific Wildlife Research Centre, Delta, British Columbia V4K 3N2 (Canada); Department of Biological Science, Simon Fraser University, Burnaby, BC V5A 1S6 (Canada); Brogan, Jason [Department of Biological Science, Simon Fraser University, Burnaby, BC V5A 1S6 (Canada); Lee, Sandi L. [Environment Canada, Science & Technology Branch, Pacific Wildlife Research Centre, Delta, British Columbia V4K 3N2 (Canada); Drouillard, Ken G. [Great Lakes Institute for Environmental Research, University of Windsor, Windsor, ON N9B 3P4 (Canada); Elliott, Kyle H. [Department of Natural Resource Sciences, McGill University, Ste. Anne de Bellevue, Quebec H9X 3V9 (Canada)

    2015-08-15

    As urban sprawl and agricultural intensification continue to invade prime wildlife habitat, some animals, even apex predators, are managing to adapt to this new environment. Chemical pollution is one of many stressors that wildlife encounter in urban environments. Predators are particularly sensitive to persistent chemical pollutants because they feed at a high trophic level where such pollution is biomagnified. To examine levels of pollution in urban birds of prey in the Lower Mainland region of British Columbia, Canada, we analyzed persistent organic contaminants in adult birds found dead of trauma injury. The hepatic geometric mean concentration of sum polybrominated diphenyl ethers (∑PBDEs) in 13 Cooper's hawks (Accipiter cooperii) from Greater Vancouver was 1873 ng/g (lipid weight) with one bird reaching 197,000 ng/g lipid weight, the highest exposure reported to date for a wild bird. Concentrations of ∑PBDEs, ∑PCBs (polychlorinated biphenyls) and, surprisingly, cyclodiene insecticides were greatest in the urban environment while those of DDE (1,1-dichloroethylene bis[p-chlorophenyl) were highest in a region of intensive agriculture. The level of most chlorinated and brominated contaminants increased with trophic level (δ{sup 15}N). The concentrations of some contaminants, PBDEs in particular, in these birds of prey may have some toxicological consequences. Apex predators in urban environments continue to be exposed to elevated concentrations of legacy pollutants as well as more recent brominated pollutants. - Highlights: • As urban areas expand, many animal species are adapting and invading urban areas. • Urban colonists encounter many new stressors, especially chemical pollution. • Urban birds of prey in Canada had high levels of brominated flame retardants (PBDEs). • One individual had the highest level of PBDEs ever recorded for wildlife. • Such high levels may have had toxicological implications.

  2. PBDEs and other POPs in urban birds of prey partly explained by trophic level and carbon source

    International Nuclear Information System (INIS)

    As urban sprawl and agricultural intensification continue to invade prime wildlife habitat, some animals, even apex predators, are managing to adapt to this new environment. Chemical pollution is one of many stressors that wildlife encounter in urban environments. Predators are particularly sensitive to persistent chemical pollutants because they feed at a high trophic level where such pollution is biomagnified. To examine levels of pollution in urban birds of prey in the Lower Mainland region of British Columbia, Canada, we analyzed persistent organic contaminants in adult birds found dead of trauma injury. The hepatic geometric mean concentration of sum polybrominated diphenyl ethers (∑PBDEs) in 13 Cooper's hawks (Accipiter cooperii) from Greater Vancouver was 1873 ng/g (lipid weight) with one bird reaching 197,000 ng/g lipid weight, the highest exposure reported to date for a wild bird. Concentrations of ∑PBDEs, ∑PCBs (polychlorinated biphenyls) and, surprisingly, cyclodiene insecticides were greatest in the urban environment while those of DDE (1,1-dichloroethylene bis[p-chlorophenyl) were highest in a region of intensive agriculture. The level of most chlorinated and brominated contaminants increased with trophic level (δ15N). The concentrations of some contaminants, PBDEs in particular, in these birds of prey may have some toxicological consequences. Apex predators in urban environments continue to be exposed to elevated concentrations of legacy pollutants as well as more recent brominated pollutants. - Highlights: • As urban areas expand, many animal species are adapting and invading urban areas. • Urban colonists encounter many new stressors, especially chemical pollution. • Urban birds of prey in Canada had high levels of brominated flame retardants (PBDEs). • One individual had the highest level of PBDEs ever recorded for wildlife. • Such high levels may have had toxicological implications

  3. Affinity Induced Surface Functionalization of Liposomes Using Cu-Free Click Chemistry

    DEFF Research Database (Denmark)

    Bak, Martin; Jølck, Rasmus Irming; Eliasen, Rasmus;

    2016-01-01

    be used for functionalization of other nanoparticles or solid surfaces. The method exploits a synergistic effect of having both affinity and covalent anchoring tags on the surface of the liposome. This was achieved by synthesizing a peptide linker system that uses Cu-free strain-promoted click...... chemistry in combination with histidine affinity tags. The investigation of post-functionalization of PEGylated liposomes was performed with a cyclic RGDfE peptide. By exploring both affinity and covalent tags a 98 ± 2.0% coupling efficiency was achieved, even a diluted system showed a coupling efficiency...

  4. One-pot synthesis of Au@SiO2 catalysts: A click chemistry approach

    KAUST Repository

    Solovyeva, Vera A.

    2014-10-13

    Using the copper-catalyzed azide-alkyne cycloaddition "click" reaction, a library of triazole amphiphiles with a variety of functional polar "heads" and hydrophobic or superhydrophobic "tails" was synthesized. The amphiphiles were evaluated for their ability to stabilize small Au nanoparticles, and, at the same time, serve as templates for nanocasting porous SiO2. One of the Au@SiO2 materials thus prepared was found to be a highly active catalyst for the Au nanoparticle-catalyzed regioselective hydroamination of alkynes.

  5. A Double-Clicking Bis-Azide Fluorogenic Dye for Bioorthogonal Self-Labeling Peptide Tags.

    Science.gov (United States)

    Demeter, Orsolya; Fodor, Eszter A; Kállay, Mihály; Mező, Gábor; Németh, Krisztina; Szabó, Pál T; Kele, Péter

    2016-04-25

    Herein, we give the very first example for the development of a fluorogenic molecular probe that combines the two-point binding specificity of biarsenical-based dyes with the robustness of bioorthogonal click-chemistry. This proof-of-principle study reports on the synthesis and fluorogenic characterization of a new, double-quenched, bis-azide fluorogenic probe suitable for bioorthogonal two-point tagging of small peptide tags by double strain-promoted azide-alkyne cycloaddition. The presented probe exhibits remarkable increase in fluorescence intensity when reacted with bis-cyclooctynylated peptide sequences, which could also serve as possible self-labeling small peptide tag motifs. PMID:27010966

  6. Simple route of caspase-3 FRET sensor synthesis using “click chemistry”

    Czech Academy of Sciences Publication Activity Database

    Lišková, Marcela; Křenková, Jana; Klepárník, Karel; Pazdera, P.; Foret, František

    Brno: Ústav analytické chemie AV ČR, v. v. i, 2015 - (Foret, F.; Křenková, J.; Drobníková, I.; Klepárník, K.), s. 137-140 ISBN 978-80-904959-3-7. [CECE 2015. International Interdisciplinary Meeting on Bioanalysis /12./. Brno (CZ), 21.09.2015-23.09.2015] R&D Projects: GA ČR(CZ) GA14-28254S Institutional support: RVO:68081715 Keywords : caspases * click chemistry * cell analysis Subject RIV: CB - Analytical Chemistry, Separation http://www.ce-ce.org/CECE2015/CECE%202015%20proceedings_full.pdf

  7. Simple route of caspase-3 FRET sensor synthesis using “click chemistry”

    Czech Academy of Sciences Publication Activity Database

    Lišková, Marcela; Křenková, Jana; Klepárník, Karel; Pazdera, P.; Foret, František

    Brno : Ústav analytické chemie AV ČR, v. v. i, 2015 - (Foret, F.; Křenková, J.; Drobníková, I.; Klepárník, K.), s. 137-140 ISBN 978-80-904959-3-7. [CECE 2015. International Interdisciplinary Meeting on Bioanalysis /12./. Brno (CZ), 21.09.2015-23.09.2015] R&D Projects: GA ČR(CZ) GA14-28254S Institutional support: RVO:68081715 Keywords : caspases * click chemistry * cell analysis Subject RIV: CB - Analytical Chemistry, Separation http://www.ce-ce.org/CECE2015/CECE%202015%20proceedings_full.pdf

  8. Star-Shaped Polyacrylates: Highly Functionalized Architectures via CuAAC Click Conjugation.

    Science.gov (United States)

    Lammens, Mieke; Fournier, David; Fijten, Martin W M; Hoogenboom, Richard; Prez, Filip Du

    2009-12-01

    Well-defined functional star-shaped polymer structures with up to 29 arms have been successfully synthesized by the combination of atom transfer radical polymerization (ATRP) and click chemistry. First, azide end-functionalized poly(isobornyl acrylate) (PiBA) star-shaped polymers were prepared by successive ATRP and bromine substitution. Subsequently, alkyne end-functionalized molecules and polymers were introduced onto the star-shaped PiBA bearing pendant azide moieties by copper-catalyzed azide-alkyne cycloaddition (CuAAC). The possibilities and limits for the CuAAC on such highly branched polyacrylates are described. PMID:21638494

  9. Synthesis and versatile applications of oligoethylene glycol dendrons using click chemistry

    OpenAIRE

    Fransen, Peter

    2013-01-01

    Los dendrímeros son una clase de macromoléculas que se caracterizan por tener una estructura altamente ramificada. Los dendrímeros contienen una superficie multivalente con los grupos funcionales, un núcleo donde empieza la ramificación eun interior constituido por los puntos de ramificación y los espacios vacíos entre las ramas. Las propiedades más interesantes de los dendrímeros incluyen su monodispersidad, multivalencia y geometría globular. La química click es un ¿grupo de reaccione...

  10. Click chemistry as a powerful tool for conjugation of targeting peptides to polymer carriers

    Czech Academy of Sciences Publication Activity Database

    Pola, Robert; Pechar, Michal; Ulbrich, Karel

    Heraklion : University of Crete, 2012. s. 61-62. [BIONANOTOX 2012 - "Biomaterials and Bionanomaterials: Recent Problems and Safety Issues", Russian-Hellenic Symposium with International Participation and Young Scientists School /3./, Advanced Research Workshop on Nanotechnologies & Bioanalytical Advances for Improved Public Security and Enviromental Safety and Health. 06.05.2012-13.05.2012, Heraklion] R&D Projects: GA AV ČR IAAX00500803 Institutional research plan: CEZ:AV0Z40500505 Institutional support: RVO:61389013 Keywords : HPMA * peptides * "click" chemistry Subject RIV: CD - Macromolecular Chemistry

  11. Synthesis of Donor-Acceptor Conjugated Polymers by "CLICK" Polymerization for OPV applications

    DEFF Research Database (Denmark)

    Brandt, Rasmus Guldbæk; Yu, Donghong

    The intent of this study was to utilize the Copper(I)-catalyzed Azide Alkyne Cycloaddition (CuAAC) as a polymerization technique (“Click” Polymerization) for synthesizing novel π-conjugated low band gap polymers for organic photovoltaic applications (OPV). The chosen approach was to synthesize an...... alternating electron donating (donor, D) and electron withdrawing (acceptor, A) co-polymer. The chosen monomers were well known units, and the novelty lies in using the monomer units with the click methodology. An insoluble alternating copolymer consisting of 2,7-diazido-9,9-dioctyl-9Hflourene and 1...

  12. A multi-source satellite data approach for modelling Lake Turkana water level: calibration and validation using satellite altimetry data

    OpenAIRE

    Velpuri, N. M.; G. B. Senay; K. O. Asante

    2012-01-01

    Lake Turkana is one of the largest desert lakes in the world and is characterized by high degrees of inter- and intra-annual fluctuations. The hydrology and water balance of this lake have not been well understood due to its remote location and unavailability of reliable ground truth datasets. Managing surface water resources is a great challenge in areas where in-situ data are either limited or unavailable. In this study, multi-source satellite-driven data such as satellite-based rainfall es...

  13. Low level impurities in imported wheat are a likely source of feral transgenic oilseed rape (Brassica napus L.) in Switzerland

    OpenAIRE

    Schulze, Juerg; Brodmann, Peter; Oehen,Bernadette; Bagutti, Claudia

    2015-01-01

    In Switzerland, the cultivation of genetically modified (GM) oilseed rape (Brassica napus L.) and the use of its seeds for food and feed are not permitted. Nevertheless, the GM oilseed rape events GT73, MS8×RF3, MS8 and RF3 have recently been found in the Rhine port of Basel, Switzerland. The sources of GM oilseed rape seeds have been unknown. The main agricultural good being imported at the Rhine port of Basel is wheat and from 2010 to 2013, 19 % of all Swiss wheat imports originated from Ca...

  14. Directive Production of Pullulan by Altering Cheap Source of Carbons and Nitrogen at 5 L Bioreactor Level

    OpenAIRE

    Sheoran, Sunil K.; Kashyap Kumar Dubey; Tiwari, D. P.; Singh, Bhanu P.

    2012-01-01

    In the present paper, attempts have been made to control the production of pullulan by supplementing commercial source of carbons and protein, timely. Pullulan production was regulated by supplying full fat soya flour and hydrolyzed soya extract, individually and in combination. Pullulan quantification was assayed for sensitivity to pullulanase. Aureobasidium pullulans was found to produce 125.7 gL−1 of pullulan. The rotation speed of shake flask, the pH of broth, and the supply of air were m...

  15. Surface Carrier Dynamics on Semiconductor Studied with Femtosecond Core-Level Photoelectron Spectroscopy Using Extreme Ultraviolet High-Order Harmonic Source

    Directory of Open Access Journals (Sweden)

    Sogawa T.

    2013-03-01

    Full Text Available We have used a femtosecond time-resolved core-level surface PES system based on the 92-eV harmonic source to study the surface carrier dynamics that induces the transient SPV on semiconductor surfaces. We clarified the temporal evolution of the transient SPV characterized by the time of the photo-generated carrier separation and recombination. This result demonstrates the potential of this technique for clarifying the initial stage of the surface carrier dynamics after photoexcitation.

  16. Surface Carrier Dynamics on Semiconductor Studied with Femtosecond Core-Level Photoelectron Spectroscopy Using Extreme Ultraviolet High-Order Harmonic Source

    Science.gov (United States)

    Oguri, K.; Tsunoi, T.; Kato, K.; Nakano, H.; Nishikawa, T.; Gotoh, H.; Tateno, K.; Sogawa, T.

    2013-03-01

    We have used a femtosecond time-resolved core-level surface PES system based on the 92-eV harmonic source to study the surface carrier dynamics that induces the transient SPV on semiconductor surfaces. We clarified the temporal evolution of the transient SPV characterized by the time of the photo-generated carrier separation and recombination. This result demonstrates the potential of this technique for clarifying the initial stage of the surface carrier dynamics after photoexcitation.

  17. Assessment of the Full Compatibility of Copper(I)-Catalyzed Alkyne-Azide Cycloaddition and Oxime Click Reactions for bis-Labelling of Oligonucleotides

    OpenAIRE

    Estalayo-Adriàn, Sandra; Lartia, Rémy; Meyer, Albert; Vasseur, Jean-Jacques; Morvan, François; Defrancq, Eric

    2014-01-01

    The conjugation of oligonucleotides with reporters is of great interest for improving their intrinsic properties or endowing new ones. In this context, we report herein a new procedure for the bis-labelling of oligonucleotides through oxime ligation (Click-O) and copper(I)-catalyzed alkyne–azide cycloaddition (Click-H). 5′-Azido and 3′-aldehyde precursors were incorporated into oligonucleotides, and subsequent coupling reactions through Click-O and Click-H (or vice versa) were successfully ac...

  18. Network Level Carbon Dioxide Emissions From On-road Sources in the Portland OR, (USA) Metropolitan Area

    Science.gov (United States)

    Powell, J.; Butenhoff, C. L.; Rice, A. L.

    2014-12-01

    To mitigate climate change, governments at multiple levels are developing policies to decrease anthropogenic carbon dioxide (CO2) emissions. The City of Portland (Oregon) and Multnomah County have adopted a Climate Action Plan with a stated goal of reducing emissions to 80% below 1990 levels by 2050. The transportation sector alone accounts for about 40% of total emissions in the Portland metropolitan area. Here we show a new street-level model of on-road mobile CO2 emissions for the Portland, OR metropolitan region. The model uses hourly traffic counter recordings made by the Portland Bureau of Transportation at 9,352 sites over 21 years (1986-2006), augmented with freeway loop detector data from the Portland Regional Transportation Archive Listing (PORTAL) transportation data archive. We constructed a land use regression model to fill in traffic network gaps with traffic counts as the dependent variable using GIS data such as road class (32 categories) and population density. The Environmental Protection Agency (EPA) MOtor Vehicle Emission Simulator (MOVES) model was used to estimate transportation CO2 emissions. The street-level emissions can be aggregated and gridded and used as input to atmospheric transport models for comparison with atmospheric measurements. This model also provides an independent assessment of top-down inventories that determine emissions from fuel sales, while being an important component of our ongoing effort to assess the effectiveness of emission mitigation strategies at the urban scale.

  19. Polychlorinated biphenyls and organochlorine pesticides in surface sediments from the sand flats of Shuangtaizi Estuary, China: levels, distribution, and possible sources.

    Science.gov (United States)

    Yuan, Xiutang; Yang, Xiaolong; Na, Guangshui; Zhang, Anguo; Mao, Yuze; Liu, Guize; Wang, Lili; Li, Xiaodong

    2015-09-01

    Levels of polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) in sediments from the sandy flat system of Shuangtaizi Estuary, the highest-latitude estuary in China, were investigated to identify their possible sources and potential ecological risk. The concentrations of 28 PCBs and 18 OCPs ranged from 1.83 to 36.68 ng g(-1) dw (mean 10.53 ng g(-1) dw) and from 0.02 to 14.57 ng g(-1) dw (mean 5.65 ng g(-1) dw), respectively. Generally, these organic pollutants showed an obvious spatial distribution, and relatively high levels were found at the high-tidal zone near river mouths. Compositional analyses indicated that tetra-PCBs were dominant for PCBs, whereas heptachlor was identified to be prevalent for OCPs in surficial sediment in the sand flats of Shuangtaizi Estuary. Overall, Shuangtaizi Estuary had moderate PCB and OCP levels in the sand flat sediments and posed a low ecological hazard to aquatic biota. Our results indicated that the sediment PCBs came from nonpoint deposition, such as atmospheric contribution and river input, for light chlorinated congeners and point source deposition, such as the industrial sources along river flow, for highly chlorinated congeners, whereas OCPs originate mainly from old residuals and new usage of pesticides in agriculture and aquaculture. PMID:25982989

  20. Source inventory for Department of Energy solid low-level radioactive waste disposal facilities: What it means and how to get one of your own

    Energy Technology Data Exchange (ETDEWEB)

    Smith, M.A. [Science Applications International Corp., Oak Ridge, TN (United States). Environmental Compliance Group

    1991-12-31

    In conducting a performance assessment for a low-level waste (LLW) disposal facility, one of the important considerations for determining the source term, which is defined as the amount of radioactivity being released from the facility, is the quantity of radioactive material present. This quantity, which will be referred to as the source inventory, is generally estimated through a review of historical records and waste tracking systems at the LLW facility. In theory, estimating the total source inventory for Department of Energy (DOE) LLW disposal facilities should be possible by reviewing the national data base maintained for LLW operations, the Solid Waste Information Management System (SWIMS), or through the annual report that summarizes the SWIMS data, the Integrated Data Base (IDB) report. However, in practice, there are some difficulties in making this estimate. This is not unexpected, since the SWIMS and the IDB were not developed with the goal of developing a performance assessment source term in mind. The practical shortcomings using the existing data to develop a source term for DOE facilities will be discussed in this paper.

  1. Population-level consequences of herbivory, changing climate, and source-sink dynamics on a long-lived invasive shrub.

    Science.gov (United States)

    van Klinken, R D; Pichancourt, J B

    2015-12-01

    Long-lived plant species are highly valued environmentally, economically, and socially, but can also cause substantial harm as invaders. Realistic demographic predictions can guide management decisions, and are particularly valuable for long-lived species where population response times can be long. Long-lived species are also challenging, given population dynamics can be affected by factors as diverse as herbivory, climate, and dispersal. We developed a matrix model to evaluate the effects of herbivory by a leaf-feeding biological control agent released in Australia against a long-lived invasive shrub (mesquite, Leguminoseae: Prosopis spp.). The stage-structured, density-dependent model used an annual time step and 10 climatically diverse years of field data. Mesquite population demography is sensitive to source-sink dynamics as most seeds are consumed and redistributed spatially by livestock. In addition, individual mesquite plants, because they are long lived, experience natural climate variation that cycles over decadal scales, as well as anthropogenic climate change. The model therefore explicitly considered the effects of both net dispersal and climate variation. Herbivory strongly regulated mesquite populations through reduced growth and fertility, but additional mortality of older plants will be required to reach management goals within a reasonable time frame. Growth and survival of seeds and seedlings were correlated with daily soil moisture. As a result, population dynamics were sensitive to rainfall scenario, but population response times were typically slow (20-800 years to reach equilibrium or extinction) due to adult longevity. Equilibrium population densities were expected to remain 5% higher, and be more dynamic, if historical multi-decadal climate patterns persist, the effect being dampened by herbivory suppressing seed production irrespective of preceding rainfall. Dense infestations were unlikely to form under a drier climate, and required net

  2. Click-Based Libraries of SFTI-1 Peptides: New Methods Using Reversed-Phase Silica.

    Science.gov (United States)

    Cistrone, Philip A; Dawson, Philip E

    2016-03-14

    Performing sequential reactions for the orthogonal derivatization of peptides in solution often requires intermediate handling and purification steps. To solve these problems, we have exploited the distinct adsorption kinetics of peptides toward particulate reversed-phase (RP) C18 silica material, enabling consecutive reactions to be performed without intermediate elution. To illustrate this approach, sequential CuAAC/click reactions were used to modify an analog of the bicyclic peptide sunflower trypsin inhibitor 1 (SFTI-1), a potent scaffold for trypsin and chymotrypsin-like enzyme inhibitors. The SFTI-1 scaffold was synthesized containing both β-azido alanine and propargyl glycine residues. Despite the mutual reactivity of these groups, site isolation on RP silica enabled consecutive click reactions and associated washing steps to be performed while the peptide remained immobilized. Importantly, this approach eliminated side products that could form between two peptides or within a single peptide. These studies suggest a broad utility for RP silica in solving both peptide handling problems and in improving synthetic workflows. PMID:26914614

  3. Synthesis and Catalytic Applications of Ruthenium(0) Nanoparticles in Click Chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Avvaru Praveen; Baek, Minwook; Sridhar, Chirumarry; Kumar, Begari Prem; Lee, Yongill [Changwon National Univ., Changwon (Korea, Republic of)

    2014-04-15

    Here we report a facile synthesis of ruthenium (Ru) Nanoparticles (NPs) by chemical co-precipitation method. The calcination of ruthenium hydroxide samples at 500 .deg. C under hydrogen atmosphere lead to the formation of Ru{sup 0} NPs. The size and aggregation of Ru NPs depends on the pH of the medium, and type of surfactant and its concentration. The X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscope image (TEM) analyses of particles indicated the formation of Ru{sup 0} NPs, and have 10 to 20 nm sizes. As-synthesized Ru{sup 0} NPs are characterized and investigated their catalytic ability in click chemistry (azide-alkyne cycloaddition reactions), showing good results in terms of reactivity. Interestingly, small structural differences in triazines influence the catalytic activity of Ru{sup 0} nanocatalysts. Click chemistry has recently emerged to become one of the most powerful tools in drug discovery, chemical biology, proteomics, medical sciences and nanotechnology/nanomedicine. In addition, preliminary tests of recycling showed good results with neither loss of activity or significant precipitation.

  4. Elastin-like recombinamer catalyst-free click gels: characterization of poroelastic and intrinsic viscoelastic properties.

    Science.gov (United States)

    González de Torre, Israel; Santos, Mercedes; Quintanilla, Luis; Testera, Ana; Alonso, Matilde; Rodríguez Cabello, José Carlos

    2014-06-01

    Elastin-like recombinamer catalyst-free click gels (ELR-CFCGs) have been prepared and characterized by modifying both a structural ELR (VKVx24) and a biofunctionalized ELR-bearing RGD cell-adhesion sequence (HRGD6) to bear the reactive groups needed to form hydrogels via a click reaction. Prior to formation of the ELR-CFCGs, azide-bearing and cyclooctyne-modified ELRs were also synthesized. Subsequent covalent crosslinking was based on the reaction between these azide and cyclooctyne groups, which takes place under physiological conditions and without the need for a catalyst. The correlation among SEM micrographs, porosity, swelling ratio, and rheological measurements have been carried out. The storage and loss moduli at 1Hz are in the range 1-10kPa and 100-1000Pa, respectively. The linear dependence of |G∗| on f(½) and the peak value of tan δ were considered to be consistent with a poroelastic mechanism dominating the frequency range 0.3-70Hz. The discrete relaxation spectrum was obtained from stress relaxation measurements (t>5s). The good fit of the relaxation modulus to decrease exponential functions suggests that an intrinsic viscoelastic mechanism dominates the transients. Several recombinamer concentrations and temperatures were tested to obtain gels with fully tuneable properties that could find applications in the biomedical field. PMID:24530853

  5. Immobilization of Cysteine-Tagged Proteins on Electrode Surfaces by Thiol-Ene Click Chemistry.

    Science.gov (United States)

    Zhang, Lin; Vilà, Neus; Klein, Tobias; Kohring, Gert-Wieland; Mazurenko, Ievgen; Walcarius, Alain; Etienne, Mathieu

    2016-07-13

    Thiol-ene click chemistry can be exploited for the immobilization of cysteine-tagged dehydrogenases in an active form onto carbon electrodes (glassy carbon and carbon felt). The electrode surfaces have been first modified with vinylphenyl groups by electrochemical reduction of the corresponding diazonium salts generated in situ from 4-vinylaniline. The grafting process has been optimized in order to not hinder the electrochemical regeneration of NAD(+)/NADH cofactor and soluble mediators such as ferrocenedimethanol and [Cp*Rh(bpy)Cl](+). Having demonstrated the feasibility of thiol-ene click chemistry for attaching ferrocene moieties onto those carbon surfaces, the same approach was then applied to the immobilization of d-sorbitol dehydrogenases with cysteine tag. These proteins can be effectively immobilized (as pointed out by XPS), and the cysteine tag (either 1 or 2 cysteine moieties at the N terminus of the polypeptide chain) was proven to maintain the enzymatic activity of the dehydrogenase upon grafting. The bioelectrode was applied to electroenzymatic enantioselective reduction of d-fructose to d-sorbitol, as a case study. PMID:27299176

  6. Recent Trends in Bioorthogonal Click-Radiolabeling Reactions Using Fluorine-18

    Directory of Open Access Journals (Sweden)

    Doreen Pietzsch

    2013-07-01

    Full Text Available The increasing application of positron emission tomography (PET in nuclear medicine has stimulated the extensive development of a multitude of novel and versatile bioorthogonal conjugation techniques especially for the radiolabeling of biologically active high molecular weight compounds like peptides, proteins or antibodies. Taking into consideration that the introduction of fluorine-18 (t1/2 = 109.8 min proceeds under harsh conditions, radiolabeling of these biologically active molecules represents an outstanding challenge and is of enormous interest. Special attention has to be paid to the method of 18F-introduction. It should proceed in a regioselective manner under mild physiological conditions, in an acceptable time span, with high yields and high specific activities. For these reasons and due to the high number of functional groups found in these compounds, a specific labeling procedure has to be developed for every bioactive macromolecule. Bioorthogonal strategies including the Cu-assisted Huisgen cycloaddition and its copper-free click variant, both Staudinger Ligations or the tetrazine-click reaction have been successfully applied and represent valuable alternatives for the selective introduction of fluorine-18 to overcome the afore mentioned obstacles. This comprehensive review deals with the progress and illustrates the latest developments in the field of bioorthogonal labeling with the focus on the preparation of radiofluorinated building blocks and tracers for molecular imaging.

  7. Neural Point-and-Click Communication by a Person With Incomplete Locked-In Syndrome.

    Science.gov (United States)

    Bacher, Daniel; Jarosiewicz, Beata; Masse, Nicolas Y; Stavisky, Sergey D; Simeral, John D; Newell, Katherine; Oakley, Erin M; Cash, Sydney S; Friehs, Gerhard; Hochberg, Leigh R

    2015-06-01

    A goal of brain-computer interface research is to develop fast and reliable means of communication for individuals with paralysis and anarthria. We evaluated the ability of an individual with incomplete locked-in syndrome enrolled in the BrainGate Neural Interface System pilot clinical trial to communicate using neural point-and-click control. A general-purpose interface was developed to provide control of a computer cursor in tandem with one of two on-screen virtual keyboards. The novel BrainGate Radial Keyboard was compared to a standard QWERTY keyboard in a balanced copy-spelling task. The Radial Keyboard yielded a significant improvement in typing accuracy and speed-enabling typing rates over 10 correct characters per minute. The participant used this interface to communicate face-to-face with research staff by using text-to-speech conversion, and remotely using an internet chat application. This study demonstrates the first use of an intracortical brain-computer interface for neural point-and-click communication by an individual with incomplete locked-in syndrome. PMID:25385765

  8. (99m)Tc-bioorthogonal click chemistry reagent for in vivo pretargeted imaging.

    Science.gov (United States)

    García, María Fernanda; Zhang, Xiuli; Shah, Manankumar; Newton-Northup, Jessica; Cabral, Pablo; Cerecetto, Hugo; Quinn, Thomas

    2016-03-15

    Metal-free click chemistry has become an important tool for pretargeted approaches in the molecular imaging field. The application of bioorthogonal click chemistry between a pretargeted trans-cyclooctene (TCO) derivatized monoclonal antibody (mAb) and a (99m)Tc-modified 1,2,4,5-tetrazine for tumor imaging was examined in vitro and in vivo. The HYNIC tetrazine compound was synthesized and structurally characterized, confirming its identity. Radiolabeling studies demonstrated that the HYNIC tetrazine was labeled with (99m)Tc at an efficiency of >95% and was radiochemically stable. (99m)Tc-HYNIC tetrazine reacted with the TCO-CC49 mAb in vitro demonstrating its selective reactivity. In vivo biodistribution studies revealed non-specific liver and GI uptake due to the hydrophobic property of the compound, however pretargeted SPECT imaging studies demonstrated tumor visualization confirming the success of the cycloaddition reaction in vivo. These results demonstrated the potential of (99m)Tc-HYNIC-tetrazine for tumor imaging with pretargeted mAbs. PMID:26875936

  9. Synthesis and amylin receptor activity of glycomimetics of pramlintide using click chemistry.

    Science.gov (United States)

    Yule, Lauren R; Bower, Rebekah L; Kaur, Harveen; Kowalczyk, Renata; Hay, Debbie L; Brimble, Margaret A

    2016-06-21

    Pramlintide (Symlin®), a synthetic analogue of the neuroendocrine hormone amylin, is devoid of the tendency to form cytotoxic amyloid fibrils and is currently used in patients with type I and type II diabetes mellitus as an adjunctive therapy with insulin or insulin analogues. As part of an on-going search for a pramlintide analogue with improved pharmacokinetic properties, we herein report the synthesis of mono- and di-glycosylated analogues of pramlintide and their activity at the AMY1(a) receptor. Introduction of N-glycosylated amino acids into the pramlintide sequence afforded the native N-linked glycomimetics whilst use of Cu(i)-catalysed azide-alkyne 1,3-dipolar cycloaddition (click) chemistry delivered 1,2,3-triazole linked glycomimetics. AMY1(a) receptor activity was retained by incorporation of single or multiple GlcNAc moieties at positions 21 and 35 of native pramlintide. Importantly, no difference in AMY1(a) activity was observed between native N-linked glycomimetics and 1,2,3-triazole linked glycomimetics demonstrating that the click variants can act as surrogates for the native N-glycosides in a biological setting. PMID:27139251

  10. Interfacial thiol-ene photo-click reactions for forming multilayer hydrogels

    Science.gov (United States)

    Shih, Han; Fraser, Andrew K.; Lin, Chien-Chi

    2014-01-01

    Interfacial visible light-mediated thiol-ene photo-click reactions were developed for preparing step-growth hydrogels with multilayer structures. The effect of a non-cleavage type photoinitiator eosin-Y on visible light-mediated thiol-ene photopolymerization was first characterized using in situ photo-rheometry, gel fraction, and equilibrium swelling ratio. Next, spectrophotometric properties of eosin-Y in the presence of various relevant macromer species were evaluated using UV/Vis spectrometry. It was determined that eosin-Y was able to re-initiate thiol-ene photo-click reaction even after light exposure. Due to its small molecular weight, most eosin-Y molecules readily leached out from the hydrogels. The diffusion of residual eosin-Y from pre-formed hydrogels was exploited for fabricating multilayer step-growth hydrogels. Interfacial hydrogel coating was formed via the same visible light-mediated gelation mechanism without adding fresh initiator. The thickness of the thiol-ene gel coating could be easily controlled by adjusting visible light exposure time, eosin-Y concentration initially loaded in the core gel, or macromer concentration in the coating solution. The major benefits of this interfacial thiol-ene coating system include its simplicity and cytocompatibility. The formation of thiol-ene hydrogels and coatings neither requires nor generates any cytotoxic components. This new gelation chemistry may have great utilities in controlled release of multiple sensitive growth factors and encapsulation of multiple cell types for tissue regeneration. PMID:23384151

  11. Click chemistry approach to conventional vegetable tanning process: accelerated method with improved organoleptic properties.

    Science.gov (United States)

    Krishnamoorthy, Ganesan; Ramamurthy, Govindaswamy; Sadulla, Sayeed; Sastry, Thotapalli Parvathaleswara; Mandal, Asit Baran

    2014-09-01

    Click chemistry approaches are tailored to generate molecular building blocks quickly and reliably by joining small units together selectively and covalently, stably and irreversibly. The vegetable tannins such as hydrolyzable and condensed tannins are capable to produce rather stable radicals or inhibit the progress of radicals and are prone to oxidations such as photo and auto-oxidation, and their anti-oxidant nature is well known. A lot remains to be done to understand the extent of the variation of leather stability, color variation (lightening and darkening reaction of leather), and poor resistance to water uptake for prolonged periods. In the present study, we have reported click chemistry approaches to accelerated vegetable tanning processes based on periodates catalyzed formation of oxidized hydrolysable and condensed tannins for high exhaustion with improved properties. The distribution of oxidized vegetable tannin, the thermal stability such as shrinkage temperature (T s) and denaturation temperature (T d), resistance to collagenolytic activities, and organoleptic properties of tanned leather as well as the evaluations of eco-friendly characteristics were investigated. Scanning electron microscopic analysis indicates the cross section of tightness of the leather. Differential scanning calorimetric analysis shows that the T d of leather is more than that of vegetable tanned or equal to aldehyde tanned one. The leathers exhibited fullness, softness, good color, and general appearance when compared to non-oxidized vegetable tannin. The developed process benefits from significant reduction in total solids and better biodegradability in the effluent, compared to non-oxidized vegetable tannins. PMID:24888617

  12. Validity and Reliability of GraphClick and DataThief III for Data Extraction.

    Science.gov (United States)

    Flower, Andrea; McKenna, John William; Upreti, Gita

    2016-05-01

    Researchers frequently rely on meta-analyses of prior research studies to efficiently evaluate a broad spectrum of results on a particular topic. In the realm of single-subject experimental designs (SSEDs), meta-analyses have a particular cachet: retaining the rigor of single-subject designs with the added robustness of replication to more fully determine the strength of a given approach or intervention. Until recently, researchers wishing to undertake meta-analytic research themselves have had limited options for synthesizing the intervention effects of a collection of studies. Researchers consistently use two software programs, DataThief III and GraphClick, to conduct meta-analytic work using SSEDs. The purpose of this study was to evaluate and compare the validity and reliability of the results yielded by each of these programs when evaluating the results of multiple research studies on the Good Behavior Game, a classroom-based intervention that has been in practice since 1969. Study findings suggest that both GraphClick and DataThief III provide valid methods of data extraction. In addition, both programs allow for reliable extraction of data between raters and between software programs. Limitations and directions for future research are explored. PMID:26611466

  13. Music, clicks, and their imaginations favor differently the event-based timing component for rhythmic movements.

    Science.gov (United States)

    Bravi, Riccardo; Quarta, Eros; Del Tongo, Claudia; Carbonaro, Nicola; Tognetti, Alessandro; Minciacchi, Diego

    2015-06-01

    The involvement or noninvolvement of a clock-like neural process, an effector-independent representation of the time intervals to produce, is described as the essential difference between event-based and emergent timing. In a previous work (Bravi et al. in Exp Brain Res 232:1663-1675, 2014a. doi: 10.1007/s00221-014-3845-9 ), we studied repetitive isochronous wrist's flexion-extensions (IWFEs), performed while minimizing visual and tactile information, to clarify whether non-temporal and temporal characteristics of paced auditory stimuli affect the precision and accuracy of the rhythmic motor performance. Here, with the inclusion of new recordings, we expand the examination of the dataset described in our previous study to investigate whether simple and complex paced auditory stimuli (clicks and music) and their imaginations influence in a different way the timing mechanisms for repetitive IWFEs. Sets of IWFEs were analyzed by the windowed (lag one) autocorrelation-wγ(1), a statistical method recently introduced for the distinction between event-based and emergent timing. Our findings provide evidence that paced auditory information and its imagination favor the engagement of a clock-like neural process, and specifically that music, unlike clicks, lacks the power to elicit event-based timing, not counteracting the natural shift of wγ(1) toward positive values as frequency of movements increase. PMID:25837726

  14. Why are there no long distance jumpers among click-beetles (Elateridae)?

    International Nuclear Information System (INIS)

    Click-beetles jump from an inverted position without using their legs. This unique mechanism results in high vertical jumps with the jump angle restricted by the rigid morphology of the exoskeleton. We explored the option to exploit this jumping mechanism for application to small mechanical devices having to extricate themselves from rough terrain. We combined experiments on a biomimetic jumping device with a physical–mathematical model of the jump to assess the effect of morphological variation on the jumping performance. We found that through morphological change of two non-dimensional (size independent) parameters, the propulsive force powering the jump can be directed at angles as small as 40°. However, in practice jumping at such angles is precluded by loss of traction with the ground during the push-off phase. This limitation to steep jump angles is inherent to the jumping mechanism which is based on rotation of body parts about a single hinge. Such a rotation dictates a curvilinear trajectory for the center of mass during takeoff so that the vertical and horizontal accelerations occur out of phase, implying loss of traction with the ground before substantial horizontal acceleration can be reached. Thus click-beetle inspired jumping is effective mainly for making steep-angle righting jumps. (paper)

  15. Liver is the major source of elevated serum lipocalin-2 levels after bacterial infection or partial hepatectomy

    DEFF Research Database (Denmark)

    Xu, Ming-Jiang; Feng, Dechun; Wu, Hailong;

    2015-01-01

    knockout (Lcn2(Hep-/-)) mice were generated and subjected to bacterial infection (with Klesbsiella pneumoniae or Escherichia coli) or partial hepatectomy (PHx). Studies of Lcn2(Hep-/-) mice revealed that hepatocytes contributed to 25% of the low basal serum level of LCN2 protein (∼ 62 ng/mL) but were...... responsible for more than 90% of the highly elevated serum LCN2 protein level (∼ 6,000 ng/mL) postinfection and more than 60% post-PHx (∼ 700 ng/mL). Interestingly, both Lcn2(Hep-/-) and global Lcn2 knockout (Lcn2(-/-)) mice demonstrated comparable increases in susceptibility to infection with K. pneumoniae...... or E. coli. These mice also had increased enteric bacterial translocation from the gut to the mesenteric lymph nodes and exhibited reduced liver regeneration after PHx. Treatment with interleukin (IL)-6 stimulated hepatocytes to produce LCN2 in vitro and in vivo. Hepatocyte-specific ablation of the...

  16. Sources of academic self-efficacy-beliefs : The role of the specificity level of autobiographical memories about academic performance

    OpenAIRE

    Vanlede, Marie; Bourgeois, Etienne; Galand, Benoît; Philippot, Pierre

    2009-01-01

    The impact on academic self-efficacy beliefs of the specificity at which memories of past academic performance are processed was investigated. Relying on autobiographical memory (AM) theories, it was predicted that, for past academic failures, which represent a threat to self-efficacy beliefs, specific processing would help in maintaining high selfefficacy beliefs compared to general processing. For past academic successes, no difference was expected between the two levels of specificity. An ...

  17. Modeling Improvements for Air Source Heat Pumps using Different Expansion Devices at Varied Charge Levels Part II

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Bo [ORNL

    2011-01-01

    This paper describes steady-state performance simulations performed on a 3-ton R-22 split heat pump in heating mode. In total, 150 steady-state points were simulated, which covers refrigerant charge levels from 70 % to 130% relative to the nominal value, the outdoor temperatures at 17 F (-8.3 C), 35 F (1.7 C) and 47 F (8.3 C), indoor air flow rates from 60% to 150% of the rated air flow rate, and two types of expansion devices (fixed orifice and thermostatic expansion valve). A charge tuning method, which is to calibrate the charge inventory model based on measurements at two operation conditions, was applied and shown to improve the system simulation accuracy significantly in an extensive range of charge levels. In addition, we discuss the effects of suction line accumulator in modeling a heat pump system using either a fixed orifice or thermal expansion valve. Last, we identify the issue of refrigerant mass flow mal-distribution at low charge levels and propose an improved modeling approach.

  18. Effects of Beliefs and Concerns on User Attitudes toward Online Social Network Advertising and Their Ad Clicking Behavior

    Directory of Open Access Journals (Sweden)

    Imran Mir

    2015-08-01

    Full Text Available Since last few years social network sites (SNSs have rapidly grown in popularity and user acceptance globally. They have become the main place for social interaction, discussion and communication. Today, many businesses advertise their products on SNSs. The current study aims to assess the effects of SNSs consumers/users’ beliefs and concerns of social network advertising (SNA on their attitudes toward SNA and SNS banner ad-clicking behavior. Data was collected from a sample of 397 university students of Pakistan. Results show the beliefs of SNA as informative and entertaining have positive effects on user attitudes toward SNA and their ad-clicking behavior. Similarly, user concern of SNA as irritating has negative effects on both their attitudes toward SNA and ad-clicking behavior. Good for economy is an important socioeconomic belief which affects user attitudes toward SNA positively. The overall results indicate that utilitarian and hedonic aspects of SNA make SNS banner ads effective.

  19. A multi-criteria methodology for energy planning and developing renewable energy sources at a regional level: A case study Thassos, Greece

    International Nuclear Information System (INIS)

    Rational energy planning under the pressure of environmental and economic problems is imperative to humanity. An evaluational framework is proposed in order to support energy planning for promoting the use of renewable energy sources. A multi-criteria decision analysis is adopted, detailing exploitation of renewable energy sources (including Wind, Solar, Biomass, Geothermal, and small Hydro) for power and heat generation. The aim of this paper is the analysis and development of a multilevel decision-making structure, utilizing multiple criteria for energy planning and exploitation of Renewable Energy Sources of at the regional level. The proposed evaluation framework focuses on the use of a multi-criteria approach as a tool for supporting energy planning in the area of concern, based on a pool of qualitative and quantitative evaluation criteria. The final aim of this study is to discover the optimal amount of each Renewable Energy Source that can be produced in the region and to contribute to an optimal energy mix. In this paper, a case study for the island of Thassos, Greece is analyzed. The results prove that Renewable Energy Sources exploitation at a regional level can satisfy increasing power demands through environmental-friendly energy systems that combine wind power, biomass and PV systems. - Highlights: ► An evaluational framework is proposed in order to support energy planning. ► A multi-criteria decision analysis is adopted, detailing exploitation of RES for power and heat generation. ► The aim is to discover the optimal amount of each RES that can be produced in each region.

  20. A Five-Level Cascade Multilever Invertor Three-Phase Motor Drive Using a Single DC Source

    Energy Technology Data Exchange (ETDEWEB)

    Chiasson, J.N. (Univ. Tennessee-Knoxville)

    2006-09-15

    A method is presented showing that a 5-level cascade multilevel inverter for a three-phase permanent magnet synchronous motor drive can be implemented using only a single DC link to supply a standard 3-leg inverter along with three full H-bridges supplied by capacitors. It is shown that the capacitor voltages can be regulated while achieving an output voltage waveform that is 20% greater than that obtained using the standard 3-leg inverter alone. Finally conditions are given in terms of the power factor and modulation index that determine when the capacitor voltage can regulated.

  1. A Five-Level Cascade Multilevel Inverter Three-Phase Motor Drive Using a Single DC Source

    Energy Technology Data Exchange (ETDEWEB)

    Chiasson, J. N. [University of Tennessee, Knoxville (UTK)

    2006-10-01

    A method is presented showing that a 5-level cascade multilevel inverter for a three-phase permanent magnet sychronous motor drive can be implemented using only a single DC link to supply a standard 3-leg inverter along with three full H-bridges supplied by capacitors. It is shown that the capacitor voltages can be regulated while achieving an output voltage waveform that is 20% greater than that obained using the standard 3-leg inverter alone. Finally conditions are given in terms of the power factor and modulation index that determine when the capacitor voltage can regulated.

  2. Public funding of health at the district level in Indonesia after decentralization – sources, flows and contradictions

    Directory of Open Access Journals (Sweden)

    Harahap Nida P

    2009-04-01

    Full Text Available Abstract Background During the Suharto era public funding of health in Indonesia was low and the health services were tightly controlled by the central government; district health staff had practically no discretion over expenditure. Following the downfall of President Suharto there was a radical political, administrative and fiscal decentralization with delivery of services becoming the responsibility of district governments. In addition, public funding for health services more than doubled between 2001 and 2006. It was widely expected that services would improve as district governments now had both more adequate funds and the responsibility for services. To date there has been little improvement in services. Understanding why services have not improved requires careful study of what is happening at the district level. Methods We collected information on public expenditure on health services for the fiscal year 2006 in 15 districts in Java, Indonesia from the district health offices and district hospitals. Data obtained in the districts were collected by three teams, one for each province. Information on district government revenues were obtained from district public expenditure databases maintained by the World Bank using data from the Ministry of Finance. Results The public expenditure information collected in 15 districts as part of this study indicates district governments are reliant on the central government for as much as 90% of their revenue; that approximately half public expenditure on health is at the district level; that at least 40% of district level public expenditure on health is for personnel, almost all of them permanent civil servants; and that districts may have discretion over less than one-third of district public expenditure on health; the extent of discretion over spending is much higher in district hospitals than in the district health office and health centers. There is considerable variation between districts

  3. Public funding of health at the district level in Indonesia after decentralization – sources, flows and contradictions

    Science.gov (United States)

    Heywood, Peter; Harahap, Nida P

    2009-01-01

    Background During the Suharto era public funding of health in Indonesia was low and the health services were tightly controlled by the central government; district health staff had practically no discretion over expenditure. Following the downfall of President Suharto there was a radical political, administrative and fiscal decentralization with delivery of services becoming the responsibility of district governments. In addition, public funding for health services more than doubled between 2001 and 2006. It was widely expected that services would improve as district governments now had both more adequate funds and the responsibility for services. To date there has been little improvement in services. Understanding why services have not improved requires careful study of what is happening at the district level. Methods We collected information on public expenditure on health services for the fiscal year 2006 in 15 districts in Java, Indonesia from the district health offices and district hospitals. Data obtained in the districts were collected by three teams, one for each province. Information on district government revenues were obtained from district public expenditure databases maintained by the World Bank using data from the Ministry of Finance. Results The public expenditure information collected in 15 districts as part of this study indicates district governments are reliant on the central government for as much as 90% of their revenue; that approximately half public expenditure on health is at the district level; that at least 40% of district level public expenditure on health is for personnel, almost all of them permanent civil servants; and that districts may have discretion over less than one-third of district public expenditure on health; the extent of discretion over spending is much higher in district hospitals than in the district health office and health centers. There is considerable variation between districts. Conclusion In contrast to the promise

  4. Levels, sources and spatiotemporal variation of nutrients and micropollutants in small streams of a Mediterranean River basin.

    Science.gov (United States)

    Karaouzas, Ioannis; Lambropoulou, Dimitra A; Skoulikidis, Nikolaos T; Albanis, Triantafyllos A

    2011-11-01

    In this study, nutrients, trace metals and priority pesticide compounds were investigated for the first time in water and sediment samples in streams of the Evrotas River basin (S.E. Greece) from 2006 to 2008. The most important sources of contamination were from the entry of pesticides and nutrients into surface waters and sediments as a result of the intensive agricultural activity as well as from the uncontrolled disposal of olive mill and citrus processing wastewaters. Aquatic risk assessment revealed that all insecticides detected showed high risk, suggesting adverse effects on the stream biota. Among the metals analyzed, Cr, Ni and Ba presented the highest concentrations in sediments, however, due to natural geological processes. Multivariate statistical techniques applied for data compression, exploration and interpretation proved to be useful tools for identifying the most critical pollutants affecting the surface water quality. The findings of this study suggest that the inclusion of streams with small catchment areas into WFD monitoring and assessment programs is essential, especially those of the Mediterranean region. PMID:21918757

  5. Polycyclic aromatic hydrocarbons (PAHs) concentration levels, pattern, source identification and soil toxicity assessment in urban traffic soil of Dhanbad, India.

    Science.gov (United States)

    Suman, Swapnil; Sinha, Alok; Tarafdar, Abhrajyoti

    2016-03-01

    Present study was carried out to assess and understand potential health risk and to examine the impact of vehicular traffic on the contamination status of urban traffic soils in Dhanbad City with respect to polycyclic aromatic hydrocarbons (PAHs). Eight urban traffic sites and two control/rural site surface soils were analyzed and the contents of 13 priority PAHs was determined. Total PAH concentration at traffic sites ranged from 1.019μgg(-1) to 10.856μgg(-1) with an average value of 3.488μgg(-1). At control/rural site, average concentration of total PAHs was found to be 0.640μgg(-1). PAH pattern was dominated by four- and five-ring PAHs (contributing >50% to the total PAHs) at all the eight traffic sites. On the other hand, rural soil showed a predominance of low molecular weight three-ring PAHs (contributing >30% to the total PAHs). Indeno[123-cd]pyrene/benz[ghi]perylene (IP/BgP) ratio indicated that PAH load at the traffic sites is predominated by the gasoline-driven vehicles. The ratio of Ant/(Ant+Phe) varied from 0.03 to 0.44, averaging 0.10; Fla/(Fla+Pyr) from 0.39 to 0.954, averaging 0.52; BaA/(BaA+Chry) from 0.156 to 0.60, averaging 0.44; and IP/(IP+BgP) from 0.176 to 0.811, averaging 0.286. The results indicated that vehicular emission was the major source for PAHs contamination with moderate effect of coal combustion and biomass combustion. Carcinogenic potency of PAH load in traffic soil was nearly 6.15 times higher as compared to the control/rural soil. PMID:26747999

  6. A comprehensive assessment of mercury exposure in penguin populations throughout the Southern Hemisphere: Using trophic calculations to identify sources of population-level variation

    International Nuclear Information System (INIS)

    Highlights: • Mercury concentrations documented for 10 species of penguins (26 breeding populations). • Mercury concentrations ⩽2.00 ppm in feathers from 18/26 penguin populations. • Trophic level calculations revealed source of population-level variation in mercury. • First documentation of geographic mercury ‘hotspots’ for penguin populations. - Abstract: The wide geographic distribution of penguins (Order Sphenisciformes) throughout the Southern Hemisphere provided a unique opportunity to use a single taxonomic group as biomonitors of mercury among geographically distinct marine ecosystems. Mercury concentrations were compared among ten species of penguins representing 26 geographically distinct breeding populations. Mercury concentrations were relatively low (⩽2.00 ppm) in feathers from 18/26 populations considered. Population-level differences in trophic level explained variation in mercury concentrations among Little, King, and Gentoo penguin populations. However, Southern Rockhopper and Magellanic penguins breeding on Staten Island, Tierra del Fuego, had the highest mercury concentrations relative to their conspecifics despite foraging at a lower trophic level. The concurrent use of stable isotope and mercury data allowed us to document penguin populations at the greatest risk of exposure to harmful concentrations of mercury as a result of foraging at a high trophic level or in geographic ‘hot spots’ of mercury availability

  7. Organochlorine compounds in surface sediments from the northern coast of Cyprus, Eastern Mediterranean: Levels, possible sources and potential risk.

    Science.gov (United States)

    Kucuksezgin, F; Pazi, I; Gonul, L T; Duman, M

    2016-08-15

    Organochlorines (OCs) were determined in sediments collected from different regions of northern coast of Cyprus. The OCPs and Aroclors had a wide range from 2.78 to 306 and 15 to 325ngg(-1), respectively. The highest level was found at Yedi Dalga site. DDE was the most abundant compound. The ratios of metabolites to parent DDT showed that DDTs were derived mostly from the aged and weathered inputs. Comparing our results with the previous studies showed that POPs in sediments were found to be lower than those in samples for Mediterranean and Black Sea coasts. The SQG implied that, Aroclor1254 exceeded the TEL values, showing that adverse biological effects are expected occasionally at some of the sediment samples. DDTs were dominant and more ecotoxicological concern in the northern Cyprus. Altogether, it may be summarized that DDTs will impose ecologically hazardous impacts in the sedimentary environment at the present. PMID:27234367

  8. Assessing the Potential Hydrological Impact of the Gibe III Dam on Lake Turkana Water Level Using Multi-Source Satellite Data

    Science.gov (United States)

    Naga Manohar Velpuri; Senai, G.B.

    2012-01-01

    Lake Turkana, the largest desert lake in the world, is fed by ungauged or poorly gauged river systems. To meet the demand of electricity in the East African region, Ethiopia is currently building the Gibe III hydroelectric dam on the Omo River, which supplies more than 80% of the inflows to Lake Turkana. On completion, the Gibe III dam will be the tallest dam in Africa with a height of 241 m. However, the nature of interactions and potential impacts of regulated inflows to Lake Turkana are not well understood due to its remote location and unavailability of reliable in-situ datasets. In this study, we used 12 years (1998–2009) of existing multi-source satellite and model-assimilated global weather data. We use calibrated multi-source satellite data-driven water balance model for Lake Turkana that takes into account model routed runoff, lake/reservoir evapotranspiration, direct rain on lakes/reservoirs and releases from the dam to compute lake water levels. The model evaluates the impact of Gibe III dam using three different approaches such as (a historical approach, a knowledge-based approach, and a nonparametric bootstrap resampling approach) to generate rainfall-runoff scenarios. All the approaches provided comparable and consistent results. Model results indicated that the hydrological impact of the dam on Lake Turkana would vary with the magnitude and distribution of rainfall post-dam commencement. On average, the reservoir would take up to 8–10 months, after commencement, to reach a minimum operation level of 201 m depth of water. During the dam filling period, the lake level would drop up to 2 m (95% confidence) compared to the lake level modelled without the dam. The lake level variability caused by regulated inflows after the dam commissioning were found to be within the natural variability of the lake of 4.8 m. Moreover, modelling results indicated that the hydrological impact of the Gibe III dam would depend on the initial lake level at the time of

  9. Assessing the potential hydrological impact of the Gibe III Dam on Lake Turkana water level using multi-source satellite data

    Directory of Open Access Journals (Sweden)

    N. M. Velpuri

    2012-03-01

    Full Text Available Lake Turkana, the largest desert lake in the world, is fed by ungauged or poorly gauged river systems. To meet the demand of electricity in the East African region, Ethiopia is currently building the Gibe III hydroelectric dam on the Omo River, which supplies more than 80% of the inflows to Lake Turkana. On completion, the Gibe III dam will be the tallest dam in Africa with a height of 241 m. However, the nature of interactions and potential impacts of regulated inflows to Lake Turkana are not well understood due to its remote location and unavailability of reliable in-situ datasets. In this study, we used 12 years (1998–2009 of existing multi-source satellite and model-assimilated global weather data. We use calibrated multi-source satellite data-driven water balance model for Lake Turkana that takes into account model routed runoff, lake/reservoir evapotranspiration, direct rain on lakes/reservoirs and releases from the dam to compute lake water levels. The model evaluates the impact of Gibe III dam using three different approaches such as (a historical approach, a knowledge-based approach, and a nonparametric bootstrap resampling approach to generate rainfall-runoff scenarios. All the approaches provided comparable and consistent results. Model results indicated that the hydrological impact of the dam on Lake Turkana would vary with the magnitude and distribution of rainfall post-dam commencement. On average, the reservoir would take up to 8–10 months, after commencement, to reach a minimum operation level of 201 m depth of water. During the dam filling period, the lake level would drop up to 2 m (95% confidence compared to the lake level modelled without the dam. The lake level variability caused by regulated inflows after the dam commissioning were found to be within the natural variability of the lake of 4.8 m. Moreover, modelling results indicated that the hydrological impact of the Gibe III dam would depend on the initial lake level

  10. Assessing the potential hydrological impact of the Gibe III Dam on Lake Turkana water level using multi-source satellite data

    Science.gov (United States)

    Velpuri, N. M.; Senay, G. B.

    2012-03-01

    Lake Turkana, the largest desert lake in the world, is fed by ungauged or poorly gauged river systems. To meet the demand of electricity in the East African region, Ethiopia is currently building the Gibe III hydroelectric dam on the Omo River, which supplies more than 80% of the inflows to Lake Turkana. On completion, the Gibe III dam will be the tallest dam in Africa with a height of 241 m. However, the nature of interactions and potential impacts of regulated inflows to Lake Turkana are not well understood due to its remote location and unavailability of reliable in-situ datasets. In this study, we used 12 years (1998-2009) of existing multi-source satellite and model-assimilated global weather data. We use calibrated multi-source satellite data-driven water balance model for Lake Turkana that takes into account model routed runoff, lake/reservoir evapotranspiration, direct rain on lakes/reservoirs and releases from the dam to compute lake water levels. The model evaluates the impact of Gibe III dam using three different approaches such as (a historical approach, a knowledge-based approach, and a nonparametric bootstrap resampling approach) to generate rainfall-runoff scenarios. All the approaches provided comparable and consistent results. Model results indicated that the hydrological impact of the dam on Lake Turkana would vary with the magnitude and distribution of rainfall post-dam commencement. On average, the reservoir would take up to 8-10 months, after commencement, to reach a minimum operation level of 201 m depth of water. During the dam filling period, the lake level would drop up to 2 m (95% confidence) compared to the lake level modelled without the dam. The lake level variability caused by regulated inflows after the dam commissioning were found to be within the natural variability of the lake of 4.8 m. Moreover, modelling results indicated that the hydrological impact of the Gibe III dam would depend on the initial lake level at the time of dam

  11. Effects of two protein sources and energy level of diet on the performance of young Marchigiana bulls. 1. Infra vitam performance and carcass quality

    Directory of Open Access Journals (Sweden)

    Raffaella Tudisco

    2010-01-01

    Full Text Available The aim of this trial was to evaluate the influence of two protein sources and the energy levels of the diet on growth performance and carcass quality of young Marchigiana bulls. Eighteen weaned young bulls (129 d of age were equally divided into three groups. Until the slaughter weight (620 kg was achieved two groups were fed diets with the same protein and energy concentrations, but differing in protein sources (faba bean-FB vs soya bean meal s.e.-SB, and the last group was fed high-energy diets (HE with both protein sources in the concentrates. Body weight, daily weight gain and biological efficiency of growth at different ages and periods, and feed conversion indexes, were calculated from individual growth curves. Beginning at 180 d of age Group HE showed always significantly (P<0.01 higher body weight and daily weight gain than groups FB and SB. Moreover, group HE reached the slaughter weight and conformation earlier than the other two groups (500 vs 540 d, respectively. The protein sources affected the growth only in the first phase after weaning (body weight at 180 d: 173 vs 186 kg for groups FB and SB, respectively; P<0.01. The highest energy diets appreciably improved growing rate, but worsened feed conversion indexes. Animal and carcass measurements were not influenced either by energy intake or by dietary protein source. Group HE showed the lowest incidence of long bones (6.2 vs 6.7 vs 5.8% of cold carcass for FB, SB and HE groups respectively; P<0.01 and the highest percentage of fat (5.1 vs 4.7 vs 7.1% of cold carcass, for FB, SB and HE groups respectively; P<0.01. As respects the protein sources, only the incidence of long bones resulted significantly different between FB and SB groups (6.2 vs 6.7% of cold carcass, respectively; P<0.05. These data demonstrate that faba beans could be used as alternative sources to soya bean meal s.e., as it did not influence growth rate and feed conversion indexes in the entire experimental period

  12. Effect of supplementation of lysine producing microbes vis-a-vis source and level of dietary protein on performance and egg quality characteristics of post-peak layers

    Directory of Open Access Journals (Sweden)

    G. U. Manju

    2015-04-01

    Full Text Available Aim: The aim was to study the effect of supplementation of lysine producing microbes (LPM as an in vivo source of lysine on performance and egg quality characters of post-peak layers. Materials and Methods: BIS (1992 specified diets (except crude protein [CP] and lysine were prepared using either soybean meal (SBM or groundnut extractions (GNE or sunflower extractions (SFE with 16 and 15% CP resulting in six control diets. Further, each control diet was fortified with either synthetic lysine or LPM to meet BIS (1992 specified lysine requirement resulting in the set of 12 test diets. Each of the eighteen diets was offered to quadruplets groups of 4 post-peak (52 weeks commercial laying hens in each. The trial lasted for 119 days. Result: The results revealed that the feed consumption and body weight changes and Roche yolk color and yolk index were significantly (p ≤ 0.05 different among different treatments. However, egg production, feed efficiency, egg weight, egg shape index, Haugh unit score, albumen index and shell thickness, and net returns remained non-significant (p ≤ 0.05 among different treatments. Among main factors, protein level (16% and 15% CP made a significant (p ≤ 0.05 difference in egg production (79.6 and 75.1% and feed efficiency (2.64 and 2.81 kg feed/kg egg mass, respectively. Among protein source GNE- and SFE-based diet fed groups showed significantly (p < 0.0% higher feed consumption and body weight gain than SBM based diets fed birds. Yolk color (7.0, 7.3 and 7.3, respectively and yolk index (0.40, 0.38 and 0.43, respectively were significantly (p ≤ 0.05 different from the protein sources. CP level and Protein source interaction effects showed significant differences in albumen index and Haugh unit score. Conclusion: Optimum level of protein (16% CP and GNE as a source of protein tended to be superior in increasing the performance and egg characteristics of post-peak layers and supplementation of lysine in either

  13. Levels and sources of brominated flame retardants in human hair from urban, e-waste, and rural areas in South China

    International Nuclear Information System (INIS)

    Human hair and indoor dust from urban, e-waste, and rural areas in south China were collected and analyzed for brominated flame retardants (BFRs). BFRs concentrations in hair from occupational e-waste recycling workers were higher than those from non-occupational exposed residents in other sampling areas. Polybrominated diphenyl ethers (PBDEs) and decabromodiphenyl ethane (DBDPE) are two major BFRs in hair samples. The PBDE congener profiles in hair from the e-waste area are different from those from urban and rural areas with relatively higher contribution of lower brominated congeners. DBDPE, instead of BDE209, has become the major BFR in non-e-waste recycling areas. Significant correlations were found between hair level and dust level for DBDPE and BTBPE but not for PBDEs. The different PBDE congener profiles between dust and hair may suggest that exogenous exposure to the PBDE adsorbed on dust is not a major source of hair PBDEs. - Highlights: → In this study we examine BFRs in human hair and indoor dust from the South China. → We find that the composition of BFR in the e-waste area is different from other areas. → DBDPE, instead of BDE209, has become the major BFR in non-e-waste recycling areas. → The PBDE congener pattern in hair is different from those in indoor dust. → In this study we conclude that exogenous exposure to the PBDE is not a major source of hair PBDEs. - BFR levels in hair from different areas in South China were determined and endogenous pathway was found to be the major source of hair BFRs.

  14. Investigation of levels in ambient air near sources of Polychlorinated Biphenyls (PCBs) in Kanpur, India, and risk assessment due to inhalation.

    Science.gov (United States)

    Goel, Anubha; Upadhyay, Kritika; Chakraborty, Mrinmoy

    2016-05-01

    Polychlorinated biphenyls (PCBs) are a class of organic compounds listed as persistent organic pollutant and have been banned for use under Stockholm Convention (1972). They were used primarily in transformers and capacitors, paint, flame retardants, plasticizers, and lubricants. PCBs can be emitted through the primary and secondary sources into the atmosphere, undergo long-range atmospheric transport, and hence have been detected worldwide. Reported levels in ambient air are generally higher in urban areas. Active sampling of ambient air was conducted in Kanpur, a densely populated and industrialized city in the Indo-Gangetic Plain, for detection of 32 priority PCBs, with the aim to determine the concentration in gas/particle phase and assess exposure risk. More than 50 % of PCBs were detected in air. Occurrence in particles was dominated by heavier congeners, and levels in gas phase were below detection. Levels determined in this study are lower than the levels in Coastal areas of India but are at par with other Asian countries where majority of sites chosen for sampling were urban industrial areas. Human health risk estimates through air inhalation pathway were made in terms of lifetime average daily dose (LADD) and incremental lifetime cancer risks (ILCR). The study found lower concentrations of PCBs than guideline values and low health risk estimates through inhalation within acceptable levels, indicating a minimum risk to the adults due to exposure to PCBs present in ambient air in Kanpur. PMID:27061805

  15. Sugar microarray via click chemistry: molecular recognition with lectins and amyloid β (1–42

    Directory of Open Access Journals (Sweden)

    Erino Matsumoto, Takahiro Yamauchi, Tomohiro Fukuda and Yoshiko Miura

    2009-01-01

    Full Text Available Sugar microarrays were fabricated on various substrates via click chemistry. Acetylene-terminated substrates were prepared by forming self-assembled monolayers (SAMs on a gold substrate with alkyl-disulfide and on silicon, quartz and glass substrates with a silane-coupling reagent. The gold substrates were subjected to surface plasmon resonance measurements, and the quartz and glass substrates were subjected to spectroscopy measurements and optical microscopy observation. The saccharide-immobilized substrate on the gold substrate showed specific interaction with the corresponding lectin, and the saccharides showed inert surface properties to other proteins with a high signal-to-noise ratio. We also focused on the saccharide–protein interaction on protein amyloidosis of Alzheimer amyloid β. Amyloid β peptide showed conformation transition on the saccharide-immobilization substrate into a β-sheet, and fibril formation and amyloid aggregates were found on the specific saccharides.

  16. "Click" Chemistry: Application of Copper Metal in Cu-Catalyzed Azomethine Imine-Alkyne Cycloadditions.

    Science.gov (United States)

    Pušavec Kirar, Eva; Grošelj, Uroš; Mirri, Giorgio; Požgan, Franc; Strle, Gregor; Štefane, Bogdan; Jovanovski, Vasko; Svete, Jurij

    2016-07-15

    A series of 16 copper-catalyzed azomethine imine-alkyne cycloaddition (CuAIAC) reactions between four pyrazolidinone-1-azomethine imines and four terminal ynones gave the corresponding fluorescent cycloadducts as bimane analogues in very high yields. The applicability of CuAIAC was demonstrated by the fluorescent labeling of functionalized polystyrene and by using Cu-C and Cu-Fe as catalysts. Experimental evidence, kinetic measurements, and correlation between a clean catalyst surface and the reaction rate are in agreement with a homotopic catalytic system with catalytic Cu(I)-acetylide formed from Cu(0) by "in situ" oxidation. The availability of azomethine imines, mild reaction conditions, simple workup, and scalability make CuAIAC a viable supplement to the Cu-catalyzed azide-alkyne cycloaddition reaction in "click" chemistry. PMID:27305104

  17. Efficient Formation of Site-Specific Protein-DNA Hybrids Using Copper-Free Click Chemistry.

    Science.gov (United States)

    Mukhortava, Ann; Schlierf, Michael

    2016-07-20

    Protein-DNA hybrids have become increasingly popular molecular building blocks in bionanotechnology and single-molecule studies to synergistically combine the programmability of DNA with the chemical diversity of proteins. The growing demand for protein-DNA hybrids requires powerful strategies for their conjugation. Here, we present an efficient two-step method for protein-DNA assembly based on copper-free click chemistry. The method allows site-specificity and high coupling efficiency, while maintaining the conservation of protein activity. We compare our method to a commonly used protocol of direct linkage of maleimide-modified oligos. We demonstrate the significantly higher yield with a protein-DNA conjugate, which is analyzed using single-molecule force spectroscopy. PMID:27322198

  18. Smart tools and orthogonal click-like reactions onto small unilamellar vesicles: Additional molecular data

    Directory of Open Access Journals (Sweden)

    Maria Vittoria Spanedda

    2015-12-01

    Full Text Available We present here the synthetic routes and the experimental data (NMR and MS spectra for model reactions for copper-free Huisgen 1,4-cycloaddition, Staudinger ligation and for addition of a dithiol on a dibromomaleimide ring. Starting materials were synthesized from the commercially available 4-chlorophenethylamine, previously described 2-(cyclooct-2-yn-1-yloxyacetic acid, 1-fluorocyclooct-2-ynecarboxylic acid, commercial 2-(diphenylphosphinoterephthalic acid 1-methyl 4-pentafluorophenyl diester and dibromomaleimide. In all cases, the expected compounds were obtained with good yield (50% to quantitative. A novel synthesis of the lipid anchor DOGP3NH2 is also described. These data were used as basis for the study reported in the article “Smart Tools and Orthogonal Click-like Reactions onto Small Unilamellar Vesicles” in Chemistry and Physics of Lipids [1].

  19. The Click Reaction as an Efficient Tool for the Construction of Macrocyclic Structures

    Directory of Open Access Journals (Sweden)

    Dario Pasini

    2013-08-01

    Full Text Available The Cu(I-catalyzed azide-alkyne cycloaddition (CuAAC, known as the click reaction is an established tool used for the construction of complex molecular architectures. Given its efficiency it has been widely applied for bioconjugation, polymer and dendrimer synthesis. More recently, this reaction has been utilized for the efficient formation of rigid or shape-persistent, preorganized macrocyclic species. This strategy also allows the installment of useful functionalities, in the form of polar and function-rich 1,2,3-triazole moieties, directly embedded in the macrocyclic structures. This review analyzes the state of the art in this context, and provides some elements of perspective for future applications.

  20. Sugar microarray via click chemistry: molecular recognition with lectins and amyloid β (1-42)

    Science.gov (United States)

    Matsumoto, Erino; Yamauchi, Takahiro; Fukuda, Tomohiro; Miura, Yoshiko

    2009-06-01

    Sugar microarrays were fabricated on various substrates via click chemistry. Acetylene-terminated substrates were prepared by forming self-assembled monolayers (SAMs) on a gold substrate with alkyl-disulfide and on silicon, quartz and glass substrates with a silane-coupling reagent. The gold substrates were subjected to surface plasmon resonance measurements, and the quartz and glass substrates were subjected to spectroscopy measurements and optical microscopy observation. The saccharide-immobilized substrate on the gold substrate showed specific interaction with the corresponding lectin, and the saccharides showed inert surface properties to other proteins with a high signal-to-noise ratio. We also focused on the saccharide-protein interaction on protein amyloidosis of Alzheimer amyloid β. Amyloid β peptide showed conformation transition on the saccharide-immobilization substrate into a β-sheet, and fibril formation and amyloid aggregates were found on the specific saccharides.