WorldWideScience

Sample records for groundbased detection strategies

  1. Ground-based Nuclear Detonation Detection (GNDD) Technology Roadmap

    International Nuclear Information System (INIS)

    Casey, Leslie A.

    2014-01-01

    This GNDD Technology Roadmap is intended to provide guidance to potential researchers and help management define research priorities to achieve technology advancements for ground-based nuclear explosion monitoring science being pursued by the Ground-based Nuclear Detonation Detection (GNDD) Team within the Office of Nuclear Detonation Detection in the National Nuclear Security Administration (NNSA) of the U.S. Department of Energy (DOE). Four science-based elements were selected to encompass the entire scope of nuclear monitoring research and development (R&D) necessary to facilitate breakthrough scientific results, as well as deliver impactful products. Promising future R&D is delineated including dual use associated with the Comprehensive Nuclear-Test-Ban Treaty (CTBT). Important research themes as well as associated metrics are identified along with a progression of accomplishments, represented by a selected bibliography, that are precursors to major improvements to nuclear explosion monitoring.

  2. Ground-based Nuclear Detonation Detection (GNDD) Technology Roadmap

    Energy Technology Data Exchange (ETDEWEB)

    Casey, Leslie A.

    2014-01-13

    This GNDD Technology Roadmap is intended to provide guidance to potential researchers and help management define research priorities to achieve technology advancements for ground-based nuclear explosion monitoring science being pursued by the Ground-based Nuclear Detonation Detection (GNDD) Team within the Office of Nuclear Detonation Detection in the National Nuclear Security Administration (NNSA) of the U.S. Department of Energy (DOE). Four science-based elements were selected to encompass the entire scope of nuclear monitoring research and development (R&D) necessary to facilitate breakthrough scientific results, as well as deliver impactful products. Promising future R&D is delineated including dual use associated with the Comprehensive Nuclear-Test-Ban Treaty (CTBT). Important research themes as well as associated metrics are identified along with a progression of accomplishments, represented by a selected bibliography, that are precursors to major improvements to nuclear explosion monitoring.

  3. Ground-based detection of G star superflares with NGTS

    Science.gov (United States)

    Jackman, James A. G.; Wheatley, Peter J.; Pugh, Chloe E.; Gänsicke, Boris T.; Gillen, Edward; Broomhall, Anne-Marie; Armstrong, David J.; Burleigh, Matthew R.; Chaushev, Alexander; Eigmüller, Philipp; Erikson, Anders; Goad, Michael R.; Grange, Andrew; Günther, Maximilian N.; Jenkins, James S.; McCormac, James; Raynard, Liam; Thompson, Andrew P. G.; Udry, Stéphane; Walker, Simon; Watson, Christopher A.; West, Richard G.

    2018-04-01

    We present high cadence detections of two superflares from a bright G8 star (V = 11.56) with the Next Generation Transit Survey (NGTS). We improve upon previous superflare detections by resolving the flare rise and peak, allowing us to fit a solar flare inspired model without the need for arbitrary break points between rise and decay. Our data also enables us to identify substructure in the flares. From changing starspot modulation in the NGTS data we detect a stellar rotation period of 59 hours, along with evidence for differential rotation. We combine this rotation period with the observed ROSAT X-ray flux to determine that the star's X-ray activity is saturated. We calculate the flare bolometric energies as 5.4^{+0.8}_{-0.7}× 10^{34}and 2.6^{+0.4}_{-0.3}× 10^{34}erg and compare our detections with G star superflares detected in the Kepler survey. We find our main flare to be one of the largest amplitude superflares detected from a bright G star. With energies more than 100 times greater than the Carrington event, our flare detections demonstrate the role that ground-based instruments such as NGTS can have in assessing the habitability of Earth-like exoplanets, particularly in the era of PLATO.

  4. Prospects for Ground-Based Detection and Follow-up of TESS-Discovered Exoplanets

    Science.gov (United States)

    Varakian, Matthew; Deming, Drake

    2018-01-01

    The Transiting Exoplanet Survey Satellite (TESS) will monitor over 200,000 main sequence dwarf stars for exoplanetary transits, with the goal of discovering small planets orbiting stars that are bright enough for follow-up observations. We here evaluate the prospects for ground-based transit detection and follow-up of the TESS-discovered planets. We focus particularly on the TESS planets that only transit once during each 27.4 day TESS observing window per region, and we calculate to what extent ground-based recovery of additional transits will be possible. Using simulated exoplanet systems from Sullivan et al. and assuming the use of a 60-cm telescope at a high quality observing site, we project the S/N ratios for transits of such planets. We use Phoenix stellar models for stars with surface temperatures from 2500K to 12000K, and we account for limb darkening, red atmospheric noise, and missed transits due to the day-night cycle and poor weather.

  5. Chlorine oxide in the stratospheric ozone layer: ground-based detection and measurement.

    Science.gov (United States)

    Parrish, A; DE Zafra, R L; Solomon, P M; Barrett, J W; Carlson, E R

    1981-03-13

    Stratospheric chlorine oxide, a significant intermediate product in the catalytic destruction of ozone by atomic chlorine, has been detected and measured by a ground-based 204-gigahertz, millimeter-wave receiver. Data taken at latitude 42 degrees N on 17 days between 10 January and 18 February 1980 yield an average chlorine oxide column density of approximately 1.05 x 10(14) per square centimeter or approximately 2/3 that of the average of eight in situ balloon flight measurements (excluding the anomalously high data of 14 July 1977) made over the past 4 years at 32 degrees N. We find less chlorine oxide below 35 kilometers and a larger vertical gradient than predicted by theoretical models of the stratospheric ozone layer.

  6. Chlorine oxide in the stratospheric ozone layer Ground-based detection and measurement

    Science.gov (United States)

    Parrish, A.; De Zafra, R. L.; Solomon, P. M.; Barrett, J. W.; Carlson, E. R.

    1981-01-01

    Stratospheric chlorine oxide, a significant intermediate product in the catalytic destruction of ozone by atomic chlorine, has been detected and measured by a ground-based 204 GHz, millimeter-wave receiver. Data taken at latitude 42 deg N on 17 days between January 10 and February 18, 1980 yield an average chlorine oxide column density of approximately 1.05 x 10 to the 14th/sq cm or approximately 2/3 that of the average of eight in situ balloon flight measurements (excluding the anomalously high data of July 14, 1977) made over the past four years at 32 deg N. Less chlorine oxide below 35 km and a larger vertical gradient than predicted by theoretical models of the stratospheric ozone layer are found.

  7. Blowing snow detection from ground-based ceilometers: application to East Antarctica

    Science.gov (United States)

    Gossart, Alexandra; Souverijns, Niels; Gorodetskaya, Irina V.; Lhermitte, Stef; Lenaerts, Jan T. M.; Schween, Jan H.; Mangold, Alexander; Laffineur, Quentin; van Lipzig, Nicole P. M.

    2017-12-01

    Blowing snow impacts Antarctic ice sheet surface mass balance by snow redistribution and sublimation. However, numerical models poorly represent blowing snow processes, while direct observations are limited in space and time. Satellite retrieval of blowing snow is hindered by clouds and only the strongest events are considered. Here, we develop a blowing snow detection (BSD) algorithm for ground-based remote-sensing ceilometers in polar regions and apply it to ceilometers at Neumayer III and Princess Elisabeth (PE) stations, East Antarctica. The algorithm is able to detect (heavy) blowing snow layers reaching 30 m height. Results show that 78 % of the detected events are in agreement with visual observations at Neumayer III station. The BSD algorithm detects heavy blowing snow 36 % of the time at Neumayer (2011-2015) and 13 % at PE station (2010-2016). Blowing snow occurrence peaks during the austral winter and shows around 5 % interannual variability. The BSD algorithm is capable of detecting blowing snow both lifted from the ground and occurring during precipitation, which is an added value since results indicate that 92 % of the blowing snow is during synoptic events, often combined with precipitation. Analysis of atmospheric meteorological variables shows that blowing snow occurrence strongly depends on fresh snow availability in addition to wind speed. This finding challenges the commonly used parametrizations, where the threshold for snow particles to be lifted is a function of wind speed only. Blowing snow occurs predominantly during storms and overcast conditions, shortly after precipitation events, and can reach up to 1300 m a. g. l. in the case of heavy mixed events (precipitation and blowing snow together). These results suggest that synoptic conditions play an important role in generating blowing snow events and that fresh snow availability should be considered in determining the blowing snow onset.

  8. Blowing snow detection from ground-based ceilometers: application to East Antarctica

    Directory of Open Access Journals (Sweden)

    A. Gossart

    2017-12-01

    Full Text Available Blowing snow impacts Antarctic ice sheet surface mass balance by snow redistribution and sublimation. However, numerical models poorly represent blowing snow processes, while direct observations are limited in space and time. Satellite retrieval of blowing snow is hindered by clouds and only the strongest events are considered. Here, we develop a blowing snow detection (BSD algorithm for ground-based remote-sensing ceilometers in polar regions and apply it to ceilometers at Neumayer III and Princess Elisabeth (PE stations, East Antarctica. The algorithm is able to detect (heavy blowing snow layers reaching 30 m height. Results show that 78 % of the detected events are in agreement with visual observations at Neumayer III station. The BSD algorithm detects heavy blowing snow 36 % of the time at Neumayer (2011–2015 and 13 % at PE station (2010–2016. Blowing snow occurrence peaks during the austral winter and shows around 5 % interannual variability. The BSD algorithm is capable of detecting blowing snow both lifted from the ground and occurring during precipitation, which is an added value since results indicate that 92 % of the blowing snow is during synoptic events, often combined with precipitation. Analysis of atmospheric meteorological variables shows that blowing snow occurrence strongly depends on fresh snow availability in addition to wind speed. This finding challenges the commonly used parametrizations, where the threshold for snow particles to be lifted is a function of wind speed only. Blowing snow occurs predominantly during storms and overcast conditions, shortly after precipitation events, and can reach up to 1300 m a. g. l.  in the case of heavy mixed events (precipitation and blowing snow together. These results suggest that synoptic conditions play an important role in generating blowing snow events and that fresh snow availability should be considered in determining the blowing snow onset.

  9. Blowing snow detection in Antarctica, from space borne and ground-based remote sensing

    Science.gov (United States)

    Gossart, A.; Souverijns, N.; Lhermitte, S.; Lenaerts, J.; Gorodetskaya, I.; Schween, J. H.; Van Lipzig, N. P. M.

    2017-12-01

    Surface mass balance (SMB) strongly controls spatial and temporal variations in the Antarctic Ice Sheet (AIS) mass balance and its contribution to sea level rise. Currently, the scarcity of observational data and the challenges of climate modelling over the ice sheet limit our understanding of the processes controlling AIS SMB. Particularly, the impact of blowing snow on local SMB is not yet constrained and is subject to large uncertainties. To assess the impact of blowing snow on local SMB, we investigate the attenuated backscatter profiles from ceilometers at two East Antarctic locations in Dronning Maud Land. Ceilometers are robust ground-based remote sensing instruments that yield information on cloud base height and vertical structure, but also provide information on the particles present in the boundary layer. We developed a new algorithm to detect blowing snow (snow particles lifted by the wind from the surface to substantial height) from the ceilometer attenuated backscatter. The algorithm successfully allows to detect strong blowing snow signal from layers thicker than 15 m at the Princess Elisabeth (PE, (72°S, 23°E)) and Neumayer (70°S, 8° W) stations. Applying the algorithm to PE, we retrieve the frequency and annual cycle of blowing snow as well as discriminate between clear sky and overcast conditions during blowing snow. We further apply the blowing snow algorithm at PE to evaluate the blowing snow events detection by satellite imagery (Palm et al., 2011): the near-surface blowing snow layers are apparent in lidar backscatter profiles and enable snowdrift events detection (spatial and temporal frequency, height and optical depth). These data are processed from CALIPSO, at a high resolution (1x1 km digital elevation model). However, the remote sensing detection of blowing snow events by satellite is limited to layers of a minimal thickness of 20-30 m. In addition, thick clouds, mostly occurring during winter storms, can impede drifting snow

  10. Potential use of ground-based sensor technologies for weed detection.

    Science.gov (United States)

    Peteinatos, Gerassimos G; Weis, Martin; Andújar, Dionisio; Rueda Ayala, Victor; Gerhards, Roland

    2014-02-01

    Site-specific weed management is the part of precision agriculture (PA) that tries to effectively control weed infestations with the least economical and environmental burdens. This can be achieved with the aid of ground-based or near-range sensors in combination with decision rules and precise application technologies. Near-range sensor technologies, developed for mounting on a vehicle, have been emerging for PA applications during the last three decades. These technologies focus on identifying plants and measuring their physiological status with the aid of their spectral and morphological characteristics. Cameras, spectrometers, fluorometers and distance sensors are the most prominent sensors for PA applications. The objective of this article is to describe-ground based sensors that have the potential to be used for weed detection and measurement of weed infestation level. An overview of current sensor systems is presented, describing their concepts, results that have been achieved, already utilized commercial systems and problems that persist. A perspective for the development of these sensors is given. © 2013 Society of Chemical Industry.

  11. Strategies of Life Detection

    CERN Document Server

    Botta, Oliver; Gomez-Elvira, Javier; Javaux, Emmanuelle; Selsis, Franck; Summons, Roger

    2008-01-01

    The search for life outside the Earth has been one of mankind's most challenging quests. We have reached a level of technology that allows for initial steps toward thorough scientific investigation. The aim of this workshop was to take an interdisciplinary look at the signatures that would be indicative of past or present life on another planet and compare them to biosignatures on Earth. The purpose of the workshop was also to discuss state-of-the-art in-situ instruments that are envisioned to search for these signatures in the exploration of the solar system, as well as the discussion of concepts descriptive of the search for habitable planets around other stars. This book is intended to provide a reference to scientists and instrument developers working in the field of in-situ and remote life detection. It can also be used as an interdisciplinary introduction for students and post-doctoral researchers entering this new and exciting field.

  12. Research on Ground-Based LWIR Hyperspectral Imaging Remote Gas Detection.

    Science.gov (United States)

    Zheng, Wei-jian; Lei, Zheng-gang; Yu, Chun-chao; Yang, Zhi-xiong; Wang, Hai-yangi; Fu, Yan-peng; Li, Xun-niu; Liao, Ning-fang; Su, Jun-hong

    2016-02-01

    The new progress of ground-based long-wave infrared remote sensing is presented, which describes the windowing spatial and temporal modulation Fourier spectroscopy imaging in details. The prototype forms the interference fringes based on the corner-cube of spatial modulation of Michelson interferometer, using cooled long-wave infrared photovoltaic staring FPA (focal plane array) detector. The LWIR hyperspectral imaging is achieved by the process of collection, reorganization, correction, apodization, FFT etc. from data cube. Noise equivalent spectral radiance (NESR), which is the sensitivity index of CHIPED-1 LWIR hyperspectral imaging prototype, can reach 5.6 x 10⁻⁸ W · (cm⁻¹ · sr · cm²)⁻¹ at single sampling. The data is the same as commercial temporal modulation hyperspectral imaging spectrometer. It can prove the advantage of this technique. This technique still has space to be improved. For instance, spectral response range of CHIPED-1 LWIR hyperspectral imaging prototype can reach 11. 5 µm by testing the transmission curve of polypropylene film. In this article, choosing the results of outdoor high-rise and diethyl ether gas experiment as an example, the authors research on the detecting method of 2D distribution chemical gas VOC by infrared hyperspectral imaging. There is no observed diethyl ether gas from the infrared spectral slice of the same wave number in complicated background and low concentration. By doing the difference spectrum, the authors can see the space distribution of diethyl ether gas clearly. Hyperspectral imaging is used in the field of organic gas VOC infrared detection. Relative to wide band infrared imaging, it has some advantages. Such as, it has high sensitivity, the strong anti-interference ability, identify the variety, and so on.

  13. Monitoring Strategies of Earth Dams by Ground-Based Radar Interferometry: How to Extract Useful Information for Seismic Risk Assessment.

    Science.gov (United States)

    Di Pasquale, Andrea; Nico, Giovanni; Pitullo, Alfredo; Prezioso, Giuseppina

    2018-01-16

    The aim of this paper is to describe how ground-based radar interferometry can provide displacement measurements of earth dam surfaces and of vibration frequencies of its main concrete infrastructures. In many cases, dams were built many decades ago and, at that time, were not equipped with in situ sensors embedded in the structure when they were built. Earth dams have scattering properties similar to landslides for which the Ground-Based Synthetic Aperture Radar (GBSAR) technique has been so far extensively applied to study ground displacements. In this work, SAR and Real Aperture Radar (RAR) configurations are used for the measurement of earth dam surface displacements and vibration frequencies of concrete structures, respectively. A methodology for the acquisition of SAR data and the rendering of results is described. The geometrical correction factor, needed to transform the Line-of-Sight (LoS) displacement measurements of GBSAR into an estimate of the horizontal displacement vector of the dam surface, is derived. Furthermore, a methodology for the acquisition of RAR data and the representation of displacement temporal profiles and vibration frequency spectra of dam concrete structures is presented. For this study a Ku-band ground-based radar, equipped with horn antennas having different radiation patterns, has been used. Four case studies, using different radar acquisition strategies specifically developed for the monitoring of earth dams, are examined. The results of this work show the information that a Ku-band ground-based radar can provide to structural engineers for a non-destructive seismic assessment of earth dams.

  14. Monitoring Strategies of Earth Dams by Ground-Based Radar Interferometry: How to Extract Useful Information for Seismic Risk Assessment

    Directory of Open Access Journals (Sweden)

    Andrea Di Pasquale

    2018-01-01

    Full Text Available The aim of this paper is to describe how ground-based radar interferometry can provide displacement measurements of earth dam surfaces and of vibration frequencies of its main concrete infrastructures. In many cases, dams were built many decades ago and, at that time, were not equipped with in situ sensors embedded in the structure when they were built. Earth dams have scattering properties similar to landslides for which the Ground-Based Synthetic Aperture Radar (GBSAR technique has been so far extensively applied to study ground displacements. In this work, SAR and Real Aperture Radar (RAR configurations are used for the measurement of earth dam surface displacements and vibration frequencies of concrete structures, respectively. A methodology for the acquisition of SAR data and the rendering of results is described. The geometrical correction factor, needed to transform the Line-of-Sight (LoS displacement measurements of GBSAR into an estimate of the horizontal displacement vector of the dam surface, is derived. Furthermore, a methodology for the acquisition of RAR data and the representation of displacement temporal profiles and vibration frequency spectra of dam concrete structures is presented. For this study a Ku-band ground-based radar, equipped with horn antennas having different radiation patterns, has been used. Four case studies, using different radar acquisition strategies specifically developed for the monitoring of earth dams, are examined. The results of this work show the information that a Ku-band ground-based radar can provide to structural engineers for a non-destructive seismic assessment of earth dams.

  15. Preliminary Assessment of Detection Efficiency for the Geostationary Lightning Mapper Using Intercomparisons with Ground-Based Systems

    Science.gov (United States)

    Bateman, Monte; Mach, Douglas; Blakeslee, Richard J.; Koshak, William

    2018-01-01

    As part of the calibration/validation (cal/val) effort for the Geostationary Lightning Mapper (GLM) on GOES-16, we need to assess instrument performance (detection efficiency and accuracy). One major effort is to calculate the detection efficiency of GLM by comparing to multiple ground-based systems. These comparisons will be done pair-wise between GLM and each other source. A complication in this process is that the ground-based systems sense different properties of the lightning signal than does GLM (e.g., RF vs. optical). Also, each system has a different time and space resolution and accuracy. Preliminary results indicate that GLM is performing at or above its specification.

  16. Strategies for dark matter detection

    International Nuclear Information System (INIS)

    Silk, J.

    1988-01-01

    The present status of alternative forms of dark matter, both baryonic and nonbaryonic, is reviewed. Alternative arguments are presented for the predominance of either cold dark matter (CDM) or of baryonic dark matter (BDM). Strategies are described for dark matter detection, both for dark matter that consists of weakly interacting relic particles and for dark matter that consists of dark stellar remnants

  17. Thermal Emission from Transiting Very-Hot Jupiters: Prospects for Ground-based Detection at Optical Wavelengths

    OpenAIRE

    Lopez-Morales, Mercedes; Seager, Sara

    2007-01-01

    Very hot Jupiters (VHJs) are defined as Jupiter-mass extrasolar planets with orbital periods shorter than three days. For low albedos the effective temperatures of irradiated VHJs can reach 2500-3000 K. Thermal emission from VHJs is therefore potentially strong at optical wavelengths. We explore the prospects of detecting optical-wavelength thermal emission during secondary eclipse with existing ground-based telescopes. We show that OGLE-TR-56b and OGLE-TR-132b are the best suited candidates ...

  18. A case for using ground-based thermal inertia measurements to detect Martian caves.

    Science.gov (United States)

    Groemer, Gernot; Foresta, Luca; Turetschek, Thomas; Bothe, Claudia; Boyd, Andrea; Dinkelaker, Aline; Dissertori, Markus; Fasching, David; Fischer, Monika; Föger, Daniel; Frischauf, Norbert; Fritsch, Lukas; Fuchs, Harald; Gautsch, Christoph; Gerard, Stephan; Goetzloff, Linda; Gołebiowska, Izabella; Gorur, Paavan; Groemer, Gerhard; Groll, Petra; Haider, Christian; Haider, Olivia; Hauth, Eva; Hauth, Stefan; Hettrich, Sebastian; Jais, Wolfgang; Jones, Natalie; Taj-Eddine, Kamal; Karl, Alexander; Kauerhoff, Tilo; Khan, Muhammad Shadab; Kjeldsen, Andreas; Klauck, Jan; Losiak, Anna; Luger, Markus; Luger, Thomas; Luger, Ulrich; McArthur, Jane; Moser, Linda; Neuner, Julia; Orgel, Csilla; Ori, Gian Gabriele; Paternesi, Roberta; Peschier, Jarno; Pfeil, Isabella; Prock, Silvia; Radinger, Josef; Ragonig, Christoph; Ramirez, Barbara; Ramo, Wissam; Rampey, Mike; Sams, Arnold; Sams, Elisabeth; Sams, Sebastian; Sandu, Oana; Sans, Alejandra; Sansone, Petra; Scheer, Daniela; Schildhammer, Daniel; Scornet, Quentin; Sejkora, Nina; Soucek, Alexander; Stadler, Andrea; Stummer, Florian; Stumptner, Willibald; Taraba, Michael; Tlustos, Reinhard; Toferer, Ernst; Winter, Egon; Zanella-Kux, Katja

    2014-05-01

    Martian caves are regarded as one of the most interesting locations in which to search for life on the planet. Data obtained during the MARS2013 expedition at Hamar Laghdad Ridge in the Tafilalt region of Morocco indicate that even small cavities can display thermal behavior that is characteristic for caves. For example, temperature in a cavity equaled 14°C±0.1°C before sunrise, which was higher than the temperature of the ambient air (10°C±0.1°C) and proximate rocks (9°C±0.1°C) at the same time. Within 30 min after sunrise, when the temperature of surrounding rocks corresponded to 15°C, this thermal relationship reversed. Measurements were conducted under simulated spaceflight conditions, including near-real-time interpretation of data that were acquired in a complex flight planning environment. We conclude that using ground-based thermal contrast measurements, in 7-14 μm band before and after sunset, is an effective method for Mars astronauts to identify caves, possibly superior to usage of space-based or ground-penetrating data.

  19. Ionospheric scintillations at Guilin detected by GPS ground-based and radio occultation observations

    Science.gov (United States)

    Zou, Yuhua

    2011-03-01

    The occurrence of ionospheric scintillations with S4 ⩾ 0.2 was studied using GPS measurements at Guilin, China (25.29°N, 110.33°E; geomagnetic: 15.04°N, 181.98°E), a station located near the northern crest of the equatorial anomaly. The results are presented for data collected from January 2009 to March 2010. The results show that nighttime amplitude scintillations only took place in February and March of the considered years, while daytime amplitude scintillations occurred in August and December of 2009. Nighttime amplitude scintillations, observed in the south of Guilin, always occurred with phase scintillations, TEC (Total Electron Content) depletions, and ROT (Rate Of change of TEC) fluctuations. However, TEC depletions and ROT fluctuations were weak during daytime amplitude scintillations, and daytime amplitude scintillations always took place simultaneously for most of the GPS satellites which appeared over Guilin in different azimuth directions. Ground-based GPS scintillation/TEC observations recorded at Guilin and signal-to-noise-ratio (SNR) measurements obtained from GPS-COSMIC radio occultation indicate that nighttime and daytime scintillations are very likely caused by ionospheric F region irregularities and sporadic E, respectively. Moreover, strong daytime amplitude scintillations may be associated with the plasma density enhancements in ionospheric E region caused by the Perseid and Geminid meteor shower activities.

  20. Eruption precursors: Manifestations and strategies for detection

    Science.gov (United States)

    Poland, Michael; Pritchard, Matthew

    2017-04-01

    an easy question to answer. From the limited record, it appears that at least a few volcanoes follow the model. For example, deep inflation, long-period earthquakes, and CO2 emissions were detected months before the 2009 eruption of Redoubt (Alaska). In the weeks to days before the eruption onset, fumarole temperatures and SO2 emissions increased, tremor was noted, and phreatic explosions presaged the extrusion of magma at the surface. Other volcanoes buck this idealized trend. Calbuco (Chile), for instance, showed no indication of inflation or seismicity in the days to years prior to the sudden onset of a magmatic eruption in 2015, despite InSAR and seismic monitoring that should have detected such unrest. Most volcanoes seem to fall between these two extremes, providing some indication of their eruptive potential via gas, thermal, seismic, or geodetic anomalies over timescales ranging from hours to years. Given limited resources and the challenges in terrestrial monitoring of all potential long- and intermediate-term eruption precursors, strategies for exploiting the wealth of remote sensing data and integrating derived insights into models of volcanic unrest are an important investment. Short-term eruption precursors, however, are best detected by ground-based monitoring—especially seismic and geodetic instruments.

  1. Prospects for Detecting Gravitational Waves at 5 Hz with Ground-Based Detectors

    Science.gov (United States)

    Yu, Hang; Martynov, Denis; Vitale, Salvatore; Evans, Matthew; Shoemaker, David; Barr, Bryan; Hammond, Giles; Hild, Stefan; Hough, James; Huttner, Sabina; Rowan, Sheila; Sorazu, Borja; Carbone, Ludovico; Freise, Andreas; Mow-Lowry, Conor; Dooley, Katherine L.; Fulda, Paul; Grote, Hartmut; Sigg, Daniel

    2018-04-01

    We propose an upgrade to Advanced LIGO (aLIGO), named LIGO-LF, that focuses on improving the sensitivity in the 5-30 Hz low-frequency band, and we explore the upgrade's astrophysical applications. We present a comprehensive study of the detector's technical noises and show that with technologies currently under development, such as interferometrically sensed seismometers and balanced-homodyne readout, LIGO-LF can reach the fundamental limits set by quantum and thermal noises down to 5 Hz. These technologies are also directly applicable to the future generation of detectors. We go on to consider this upgrade's implications for the astrophysical output of an aLIGO-like detector. A single LIGO-LF can detect mergers of stellar-mass black holes (BHs) out to a redshift of z ≃6 and would be sensitive to intermediate-mass black holes up to 2000 M⊙. The detection rate of merging BHs will increase by a factor of 18 compared to aLIGO. Additionally, for a given source the chirp mass and total mass can be constrained 2 times better than aLIGO and the effective spin 3-5 times better than aLIGO. Furthermore, LIGO-LF enables the localization of coalescing binary neutron stars with an uncertainty solid angle 10 times smaller than that of aLIGO at 30 Hz and 4 times smaller when the entire signal is used. LIGO-LF also significantly enhances the probability of detecting other astrophysical phenomena including the tidal excitation of neutron star r modes and the gravitational memory effects.

  2. Prospects for Detecting Gravitational Waves at 5 Hz with Ground-Based Detectors.

    Science.gov (United States)

    Yu, Hang; Martynov, Denis; Vitale, Salvatore; Evans, Matthew; Shoemaker, David; Barr, Bryan; Hammond, Giles; Hild, Stefan; Hough, James; Huttner, Sabina; Rowan, Sheila; Sorazu, Borja; Carbone, Ludovico; Freise, Andreas; Mow-Lowry, Conor; Dooley, Katherine L; Fulda, Paul; Grote, Hartmut; Sigg, Daniel

    2018-04-06

    We propose an upgrade to Advanced LIGO (aLIGO), named LIGO-LF, that focuses on improving the sensitivity in the 5-30 Hz low-frequency band, and we explore the upgrade's astrophysical applications. We present a comprehensive study of the detector's technical noises and show that with technologies currently under development, such as interferometrically sensed seismometers and balanced-homodyne readout, LIGO-LF can reach the fundamental limits set by quantum and thermal noises down to 5 Hz. These technologies are also directly applicable to the future generation of detectors. We go on to consider this upgrade's implications for the astrophysical output of an aLIGO-like detector. A single LIGO-LF can detect mergers of stellar-mass black holes (BHs) out to a redshift of z≃6 and would be sensitive to intermediate-mass black holes up to 2000  M_{⊙}. The detection rate of merging BHs will increase by a factor of 18 compared to aLIGO. Additionally, for a given source the chirp mass and total mass can be constrained 2 times better than aLIGO and the effective spin 3-5 times better than aLIGO. Furthermore, LIGO-LF enables the localization of coalescing binary neutron stars with an uncertainty solid angle 10 times smaller than that of aLIGO at 30 Hz and 4 times smaller when the entire signal is used. LIGO-LF also significantly enhances the probability of detecting other astrophysical phenomena including the tidal excitation of neutron star r modes and the gravitational memory effects.

  3. Analysis of a dryline-like feature in northern Germany detected by ground-based microwave profiling

    Energy Technology Data Exchange (ETDEWEB)

    Spaenkuch, Dietrich [Leibniz-Soziaetet der Wissenschaften zu Berlin e.V. (Germany); Gueldner, Juergen [Deutscher Wetterdienst, Lindenberg (Germany). Meteorologisches Observatorium Lindenberg - Richard-Assmann-Observatorium; Bender, Michael [Helmholtz-Zentrum Potsdam, Potsdam (DE). Deutsches GeoForschungsZentrum (GFZ); Steinhagen, Hans

    2011-08-15

    Two dryline-like humidity drops without considerable temperature change were detected by the ground-based microwave radiometer profiler (MWRP) at the Richard-Assmann-Observatory Lindenberg (52.21 N, 14.12 E) on April 28, 2007. The detailed analysis of these two events includes cloud radar and radar wind profiler measurements at the site as well as data from the surface synoptic network and from integrated water vapour (IWV) maps derived from GPS. The first more pronounced humidity drop is part of a roughly 200 km long line that meets the criterion of a classical dryline or dewpoint front, namely of a moisture gradient larger 3.5 g m{sup -3} per 100 km. This dewpoint front is ahead of an approaching cold front and is caused by strong downdraft induced by low tropospheric wind shear due to weakening of a midtropospheric high over Germany. It consisted in particular in two kernels of variable size depending on their stage. The fate of the kernels - migration, speed, unification and divorce - is described in detail. Their lifetime was a bit more than 9 hours. The second humidity drop at the site was observed after the passage of the cold front and was caused by dry advection behind the front. Both events are predicted by the numerical weather prediction model COSMO-EU of the German Weather Service to some extent.

  4. Ground-based complex for detection and investigation of fast optical transients in wide field

    Science.gov (United States)

    Molinari, Emilio; Beskin, Grigory; Bondar, Sergey; Karpov, Sergey; Plokhotnichenko, Vladimir; de-Bur, Vjacheslav; Greco, Guiseppe; Bartolini, Corrado; Guarnieri, Adriano; Piccioni, Adalberto

    2008-07-01

    To study short stochastic optical flares of different objects (GRBs, SNs, etc) of unknown localizations as well as NEOs it is necessary to monitor large regions of sky with high time resolution. We developed a system which consists of wide-field camera (FOW is 400-600 sq.deg.) using TV-CCD with time resolution of 0.13 s to record and classify optical transients, and a fast robotic telescope aimed to perform their spectroscopic and photometric investigation just after detection. Such two telescope complex TORTOREM combining wide-field camera TORTORA and robotic telescope REM operated from May 2006 at La Silla ESO observatory. Some results of its operation, including first fast time resolution study of optical transient accompanying GRB and discovery of its fine time structure, are presented. Prospects for improving the complex efficiency are given.

  5. On greenhouse gas signal detection strategies

    International Nuclear Information System (INIS)

    Barnett, T.P.; Schlesinger, M.E.; Xingjian Jiang

    1990-01-01

    Important elements of a greenhouse gas signal detection strategy are discussed and demonstrated with both model and observed data. The analysis also demonstrates the high level of unexplained interdecadal variability that occurs naturally in the climate system and how this noise will greatly complicate any detection strategy. The indisputable detection of a greenhouse gas signal in the global climate system will be a true decision point for mankind. Yet, at this stage of knowledge, the details of an appropriate detection strategy are only beginning to be developed. Two key elements in the eventual strategy are the subject of this report: (1) what variables should be monitored in a detection program, and (2) the comparison of the equilibrium versus transient climate system response. Subsequent sections consider these items in turn, while a final section summarizes the main conclusion of the study

  6. Detection of pollution transport events southeast of Mexico City using ground-based visible spectroscopy measurements of nitrogen dioxide

    Directory of Open Access Journals (Sweden)

    M. Grutter

    2009-07-01

    Full Text Available This work presents ground based differential optical absorption spectroscopy (DOAS measurements of nitrogen dioxide (NO2 during the MILAGRO field campaign in March 2006 at the Tenango del Aire research site located to the southeast of Mexico City. The DOAS NO2 column density measurements are used in conjunction with ceilometer, meteorological and surface nitric oxide (NO, nitrogen oxides (NOx and total reactive nitrogen (NOy measurements to analyze pollution transport events to the southeast of Mexico City during the MILARGO field campaign. The study divides the data set into three case study pollution transport events that occurred at the Tenango del Aire research site. The unique data set is then used to provide an in depth analysis of example days of each of the pollution transport events. An in depth analysis of 13 March 2006, a Case One day, shows the transport of several air pollution plumes during the morning through the Tenango del Aire research site when southerly winds are present and demonstrates how DOAS tropospheric NO2 vertical column densities (VCD, surface NO2 mixing ratios and ceilometer data are used to determine the vertical homogeneity of the pollution layer. The analysis of 18 March 2006, a Case Two day, shows that when northerly winds are present for the entire day, the air at the Tenango del Aire research site is relatively clean and no major pollution plumes are detected. Case 3 days are characterized by relatively clean air throughout the morning with large DOAS NO2 enhancements detected in the afternoon. The analysis of 28 March 2006 show the DOAS NO2 enhancements are likely due to lightning activity and demonstrate how suitable ground-based DOAS measruements are for monitoring anthropogenic and natural pollution sources that reside above the mixing layer.

  7. A simple strategy for fall events detection

    KAUST Repository

    Harrou, Fouzi

    2017-01-20

    The paper concerns the detection of fall events based on human silhouette shape variations. The detection of fall events is addressed from the statistical point of view as an anomaly detection problem. Specifically, the paper investigates the multivariate exponentially weighted moving average (MEWMA) control chart to detect fall events. Towards this end, a set of ratios for five partial occupancy areas of the human body for each frame are collected and used as the input data to MEWMA chart. The MEWMA fall detection scheme has been successfully applied to two publicly available fall detection databases, the UR fall detection dataset (URFD) and the fall detection dataset (FDD). The monitoring strategy developed was able to provide early alert mechanisms in the event of fall situations.

  8. Application of a pilot control strategy identification technique to a joint FAA/NASA ground-based simulation of head-up displays for CTOL aircraft

    Science.gov (United States)

    Jewell, W. F.

    1982-01-01

    A technique for measuring a pilot's control strategy was developed, evaluated, and applied to a joint FAA-NASA ground-based simulation of two competing concepts of head-up displays for use in conventional takeoff and landing aircraft. The technique, called the Non-Intrusive Pilot Identification Program (NIPIP), estimates the pilot's input-output describing function and combined pilot-vehicle performance parameters such as crossover frequency and phase margin by using a time domain model of the pilot and a least-squares identification algorithm. NIPIP functions in realtime and uses a sliding time window to maintain freshness in the data; thus time-varying characteristics in the pilot's control strategy can be measured.

  9. Defense and detection strategies against Internet worms

    CERN Document Server

    Nazario, José

    2004-01-01

    This is the first book focused exclusively on Internet worms, offering you solid worm detection and mitigation strategies for your work in the field. This ground-breaking volume enables you to put rising worm trends into perspective with practical information in detection and defense techniques utilizing data from live networks, real IP addresses, and commercial tools. The book helps you understand the classifications and groupings of worms, and offers a deeper understanding of how they threaten network and system security.

  10. Bullying - effects, prevalence and strategies for detection.

    Science.gov (United States)

    Carr-Gregg, Michael; Manocha, Ramesh

    2011-03-01

    The mental, physical, social and academic consequences of bullying have an enormous impact on human and social capital. This article describes the effects and prevalence of bullying on young people and presents strategies for its detection. Strategies for the facilitation of a multidisciplinary approach to bullying in adolescents are also presented. Given the existing high rate of bullying, assessment should be incorporated into a standard psychosocial screening routine in the general practitioner's clinic. Effective management is a multidisciplinary effort, involving parents, teachers and school officials, the GP, and mental health professionals. Given the variable effectiveness of schools in tackling bullying, GPs play an important role in identifying at risk patients, screening for psychiatric comorbidities, counselling families about the problem, and advocating for bullying prevention in their communities.

  11. GROUND-BASED INFRARED DETECTIONS OF CO IN THE CENTAUR-COMET 29P/SCHWASSMANN-WACHMANN 1 AT 6.26 AU FROM THE SUN

    International Nuclear Information System (INIS)

    Paganini, Lucas; Mumma, Michael J.; DiSanti, Michael A.; Villanueva, Geronimo L.; Bonev, Boncho P.; Boehnhardt, Hermann; Lippi, Manuela; Käufl, Hans U.; Blake, Geoffrey A.

    2013-01-01

    We observed Comet 29P/Schwassmann-Wachmann 1 (hereafter, 29P) in 2012 February and May with CRIRES/VLT and NIRSPEC/Keck-II, when the comet was at 6.26 AU from the Sun and about 5.50 AU from Earth. With CRIRES, we detected five CO emission lines on several nights in each epoch, confirming the ubiquitous content and release of carbon monoxide from the nucleus. This is the first simultaneous detection of multiple lines from any (neutral) gaseous species in comet 29P at infrared wavelengths. It is also the first extraction of a rotational temperature based on the intensities of simultaneously measured spectral lines in 29P, and the retrieved rotational temperature is the lowest obtained in our infrared survey to date. We present the retrieved production rates (∼3 × 10 28 molecules s –1 ) and remarkably low (∼5 K) rotational temperatures for CO, and compare them with results from previous observations at radio wavelengths. Along with CO, we pursued detections of other volatiles, namely H 2 O, C 2 H 6 , C 2 H 2 , CH 4 , HCN, NH 3 , and CH 3 OH. Although they were not detected, we present sensitive upper limits. These results establish a new record for detections by infrared spectroscopy of parent volatiles in comets at large heliocentric distances. Until now considered to be a somewhat impossible task with IR ground-based facilities, these discoveries demonstrate new opportunities for targeting volatile species in distant comets.

  12. Target discrimination strategies in optics detection

    Science.gov (United States)

    Sjöqvist, Lars; Allard, Lars; Henriksson, Markus; Jonsson, Per; Pettersson, Magnus

    2013-10-01

    Detection and localisation of optical assemblies used for weapon guidance or sniper rifle scopes has attracted interest for security and military applications. Typically a laser system is used to interrogate a scene of interest and the retro-reflected radiation is detected. Different system approaches for area coverage can be realised ranging from flood illumination to step-and-stare or continuous scanning schemes. Independently of the chosen approach target discrimination is a crucial issue, particularly if a complex scene such as in an urban environment and autonomous operation is considered. In this work target discrimination strategies in optics detection are discussed. Typical parameters affecting the reflected laser radiation from the target are the wavelength, polarisation properties, temporal effects and the range resolution. Knowledge about the target characteristics is important to predict the target discrimination capability. Two different systems were used to investigate polarisation properties and range resolution information from targets including e.g. road signs, optical reflexes, rifle sights and optical references. The experimental results and implications on target discrimination will be discussed. If autonomous operation is required target discrimination becomes critical in order to reduce the number of false alarms.

  13. Protein lipoxidation: Detection strategies and challenges

    Directory of Open Access Journals (Sweden)

    Giancarlo Aldini

    2015-08-01

    Full Text Available Enzymatic and non-enzymatic lipid metabolism can give rise to reactive species that may covalently modify cellular or plasma proteins through a process known as lipoxidation. Under basal conditions, protein lipoxidation can contribute to normal cell homeostasis and participate in signaling or adaptive mechanisms, as exemplified by lipoxidation of Ras proteins or of the cytoskeletal protein vimentin, both of which behave as sensors of electrophilic species. Nevertheless, increased lipoxidation under pathological conditions may lead to deleterious effects on protein structure or aggregation. This can result in impaired degradation and accumulation of abnormally folded proteins contributing to pathophysiology, as may occur in neurodegenerative diseases. Identification of the protein targets of lipoxidation and its functional consequences under pathophysiological situations can unveil the modification patterns associated with the various outcomes, as well as preventive strategies or potential therapeutic targets. Given the wide structural variability of lipid moieties involved in lipoxidation, highly sensitive and specific methods for its detection are required. Derivatization of reactive carbonyl species is instrumental in the detection of adducts retaining carbonyl groups. In addition, use of tagged derivatives of electrophilic lipids enables enrichment of lipoxidized proteins or peptides. Ultimate confirmation of lipoxidation requires high resolution mass spectrometry approaches to unequivocally identify the adduct and the targeted residue. Moreover, rigorous validation of the targets identified and assessment of the functional consequences of these modifications are essential. Here we present an update on methods to approach the complex field of lipoxidation along with validation strategies and functional assays illustrated with well-studied lipoxidation targets.

  14. Combining satellite-based fire observations and ground-based lightning detections to identify lightning fires across the conterminous USA

    Science.gov (United States)

    Bar-Massada, A.; Hawbaker, T.J.; Stewart, S.I.; Radeloff, V.C.

    2012-01-01

    Lightning fires are a common natural disturbance in North America, and account for the largest proportion of the area burned by wildfires each year. Yet, the spatiotemporal patterns of lightning fires in the conterminous US are not well understood due to limitations of existing fire databases. Our goal here was to develop and test an algorithm that combined MODIS fire detections with lightning detections from the National Lightning Detection Network to identify lightning fires across the conterminous US from 2000 to 2008. The algorithm searches for spatiotemporal conjunctions of MODIS fire clusters and NLDN detected lightning strikes, given a spatiotemporal lag between lightning strike and fire ignition. The algorithm revealed distinctive spatial patterns of lightning fires in the conterminous US While a sensitivity analysis revealed that the algorithm is highly sensitive to the two thresholds that are used to determine conjunction, the density of fires it detected was moderately correlated with ground based fire records. When only fires larger than 0.4 km2 were considered, correlations were higher and the root-mean-square error between datasets was less than five fires per 625 km2 for the entire study period. Our algorithm is thus suitable for detecting broad scale spatial patterns of lightning fire occurrence, and especially lightning fire hotspots, but has limited detection capability of smaller fires because these cannot be consistently detected by MODIS. These results may enhance our understanding of large scale patterns of lightning fire activity, and can be used to identify the broad scale factors controlling fire occurrence.

  15. CAN GROUND-BASED TELESCOPES DETECT THE OXYGEN 1.27 {mu}m ABSORPTION FEATURE AS A BIOMARKER IN EXOPLANETS?

    Energy Technology Data Exchange (ETDEWEB)

    Kawahara, Hajime [Department of Physics, Tokyo Metropolitan University, Hachioji, Tokyo 192-0397 (Japan); Matsuo, Taro [Department of Astronomy, Kyoto University, Kita-Shirakawa-Oiwake-Chou, Sakyoku, Kyoto 606-8502 (Japan); Takami, Michihiro [Institute of Astronomy and Astrophysics, Academia Sinica, P.O. Box 23-141, Taipei 10617, Taiwan (China); Fujii, Yuka [Department of Physics, The University of Tokyo, Tokyo 113-0033 (Japan); Kotani, Takayuki; Tamura, Motohide [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Murakami, Naoshi [Division of Applied Physics, Faculty of Engineering, Hokkaido University, Sapporo, Hokkaido 060-8628 (Japan); Guyon, Olivier, E-mail: kawa_h@tmu.ac.jp [National Astronomical Observatory of Japan, Subaru Telescope, Hilo, HI 96720 (United States)

    2012-10-10

    The oxygen absorption line imprinted in the scattered light from Earth-like planets has been considered the most promising metabolic biomarker for exolife. We examine the feasibility of the detection of the 1.27 {mu}m oxygen band from habitable exoplanets, in particular, around late-type stars observed with a future instrument on a 30 m class ground-based telescope. We analyzed the night airglow around 1.27 {mu}m with the IRCS/echelle spectrometer on Subaru and found that the strong telluric emission from atmospheric oxygen molecules declines by an order of magnitude by midnight. By compiling nearby star catalogs combined with the sky background model, we estimate the detectability of the oxygen absorption band from an Earth twin, if it exists, around nearby stars. We find that the most dominant source of photon noise for the oxygen 1.27 {mu}m band detection comes from the night airglow if the contribution of the stellar point-spread function (PSF) halo is suppressed enough to detect the planet. We conclude that the future detectors, for which the detection contrast is limited by photon noise, can detect the oxygen 1.27 {mu}m absorption band of Earth twins for {approx}50 candidates of the late-type star. This paper demonstrates the importance of deploying a small inner working angle as an efficient coronagraph and extreme adaptive optics on extremely large telescopes, and clearly shows that doing so will enable the study of potentially habitable planets.

  16. Ground-based detectability of terrestrial and Jovian extrasolar planets: observations of CM Draconis at Lick Observatory.

    Science.gov (United States)

    Doyle, L R; Dunham, E T; Deeg, H J; Blue, J E; Jenkins, J M

    1996-06-25

    The detection of terrestrial-sized extrasolar planets from the ground has been thought to be virtually impossible due to atmospheric scintillation limits. However, we show that this is not the case especially selected (but nevertheless main sequence) stars, namely small eclipsing binaries. For the smallest of these systems, CM Draconis, several months to a few years of photometric observations with 1-m-class telescopes will be sufficient to detect the transits of any short-period planets of sizes > or = 1.5 Earth radii (RE), using cross-correlation analysis with moderately good photometry. Somewhat larger telescopes will be needed to extend this detectability to terrestrial planets in larger eclipsing binary systems. (We arbitrarily define "terrestrial planets" herein as those whose disc areas are closer to that of Earth's than Neptune's i.e., less than about 2.78 RE.) As a "spin-off" of such observations, we will also be able to detect the presence of Jovian-mass planets without transits using the timing of the eclipse minima. Eclipse minima will drift in time as the binary system is offset by a sufficiently massive planet (i.e., one Jupiter mass) about the binary/giant-planet barycenter, causing a periodic variation in the light travel time to the observer. We present here an outline of present observations taking place at the University of California Lick Observatory using the Crossley 0.9-m telescope in collaboration with other observatories (in South Korea, Crete, France, Canary Islands, and New York) to detect or constrain the existence of terrestrial planets around main sequence eclipsing binary star systems, starting with CM Draconis. We demonstrate the applicability of photometric data to the general detection of gas giant planets via eclipse minima timings in many other small-mass eclipsing binary systems as well.

  17. The development and deployment of a ground-based, laser-induced fluorescence instrument for the in situ detection of iodine monoxide radicals

    International Nuclear Information System (INIS)

    Thurlow, M. E.; Hannun, R. A.; Lapson, L. B.; Anderson, J. G.; Co, D. T.; O'Brien, A. S.; Hanisco, T. F.

    2014-01-01

    High abundances of iodine monoxide (IO) are known to exist and to participate in local photochemistry of the marine boundary layer. Of particular interest are the roles IO plays in the formation of new particles in coastal marine environments and in depletion episodes of ozone and mercury in the Arctic polar spring. This paper describes a ground-based instrument that measures IO at mixing ratios less than one part in 10 12 . The IO radical is measured by detecting laser-induced fluorescence at wavelengths longer that 500 nm. Tunable visible light is used to pump the A 2 Π 3/2 (v ′ = 2) ← X 2 Π 3/2 (v ″ = 0) transition of IO near 445 nm. The laser light is produced by a solid-state, Nd:YAG-pumped Ti:Sapphire laser at 5 kHz repetition rate. The laser-induced fluorescence instrument performs reliably with very high signal-to-noise ratios (>10) achieved in short integration times (<1 min). The observations from a validation deployment to the Shoals Marine Lab on Appledore Island, ME are presented and are broadly consistent with in situ observations from European Coastal Sites. Mixing ratios ranged from the instrumental detection limit (<1 pptv) to 10 pptv. These data represent the first in situ point measurements of IO in North America

  18. The Development and Deployment of a Ground-Based, Laser-Induced Fluorescence Instrument for the In Situ Detection of Iodine Monoxide Radicals

    Science.gov (United States)

    Thurlow, M. E.; Co, D. T.; O'Brien, A. S.; Hannun, R. A.; Lapson, L. B.; Hanisco, T. F.; Anderson, J. G.

    2014-01-01

    High abundances of iodine monoxide (IO) are known to exist and to participate in local photochemistry of the marine boundary layer. Of particular interest are the roles IO plays in the formation of new particles in coastal marine environments and in depletion episodes of ozone and mercury in the Arctic polar spring. This paper describes a ground-based instrument that measures IO at mixing ratios less than one part in 1012. The IO radical is measured by detecting laser-induced fluorescence at wavelengths longer that 500 nm. Tunable visible light is used to pump the A23/2 (v = 2) ? X23/2 (v = 0) transition of IO near 445 nm. The laser light is produced by a solid-state, Nd:YAG-pumped Ti:Sapphire laser at 5 kHz repetition rate. The laser-induced fluorescence instrument performs reliably with very high signal-to-noise ratios (>10) achieved in short integration times (<1 min). The observations from a validation deployment to the Shoals Marine Lab on Appledore Island, ME are presented and are broadly consistent with in situ observations from European Coastal Sites. Mixing ratios ranged from the instrumental detection limit (<1 pptv) to 10 pptv. These data represent the first in situ point measurements of IO in North America.

  19. Ground-based Detection of Deuterated Water in Comet C/2014 Q2 (Lovejoy) at IR Wavelengths

    Energy Technology Data Exchange (ETDEWEB)

    Paganini, L.; Mumma, M. J.; Villanueva, G. L. [Goddard Center for Astrobiology, NASA Goddard Space Flight Center, Greenbelt, MD (United States); Gibb, E. L. [Department of Physics and Astronomy, University of Missouri, St. Louis, MO (United States)

    2017-02-20

    We conducted a deep search for deuterated water (HDO) in the Oort Cloud comet C/2014 Q2 (Lovejoy), through infrared (IR) spectroscopy with NIRSPEC at the Keck Observatory. In this Letter, we present our detections of HDO and water (H{sub 2}O) in comet Lovejoy on 2015 February 4 (post-perihelion) after 1 hr integration on source. The IR observations allowed simultaneous detection of H{sub 2}O and HDO, yielding production rates of 5.9 ± 0.13 × 10{sup 29} and 3.6 ± 1.0 × 10{sup 26} molecules s{sup −1}, respectively. The simultaneous detection permitted accurate determination of the isotopic ratio (D/H) in water of 3.02 ± 0.87 × 10{sup −4}, i.e., larger than the value for water in terrestrial oceans (or Vienna Standard Mean Ocean Water, VSMOW) by a factor of 1.94 ± 0.56. This D/H ratio in water exceeds the value obtained independently at millimeter wavelengths (0.89 ± 0.25 VSMOW; pre-perihelion). We discuss these parameters in the context of origins and emphasize the need for contemporaneous measurements of HDO and H{sub 2}O.

  20. An new algorithm to detect blowing snow from ground-based remote sensing ceilometer observations in Dronning Maud Land, East Antarctica.

    Science.gov (United States)

    Gossart, Alexandra; Souverijns, Niels; Gorodetskaya, Irina V.; Lhermitte, Stef; Lenaerts, Jan T. M.; Schween, Jan H.; van Lipzig, Nicole P. M.

    2017-04-01

    Surface mass balance (SMB) strongly controls spatial and temporal variations in the Antarctic Ice Sheet (AIS) mass balance and its contribution to sea level rise. Currently, the scarcity of observational data and the challenges of climate modeling over the ice sheet limit our understanding of the processes controlling AIS SMB. Particularly, the impact of blowing snow on local SMB is not yet constrained and is subject to large uncertainties. Tho assess the impact of blowing snow on local SMB, we investigate the 15-sec attenuated backscatter profiles from 910 nm ceilometers at two East Antarctic locations in Dronning Maud Land. Ceilometers are robust ground-based remote sensing instruments that can withstand harsh conditions unmanned and produce data continuously. In addition to yielding information on cloud base height and vertical structure, these instruments also provide information on the particles present in the boundary layer. We developed a new algorithm to detect blowing snow (snow particles lifted by the wind from the surface to substantial height) from the ceilometer attenuated backscatter. The algorithm routinely detects the presence of blowing snow if 1) a certain threshold is be exceeded at the range bin closest to the ground (signaling a large concentration of scatterers), and 2) if the intensity of the signal decreases with height (signature of the presence of a blowing snow layer). The algorithm successfully allows to detect strong blowing snow signal from layers thicker than 15 m at the Princess Elisabeth (PE, 72°S, 23°E) and Neumayer (70°S, 8° W) stations in Dronning Maud Land, East Antarctica. Moreover, we combined the ceilometer with automatic weather stations to understand key conditions for blowing snow at the study locations. Results show a very good match between the blowing snow events detected by the new algorithm and visual observations at Neumayer station. Applying the algorithm to PE station, we retrieve the frequency and annual cycle

  1. Improved instrumental line shape monitoring for the ground-based, high-resolution FTIR spectrometers of the Network for the Detection of Atmospheric Composition Change

    Directory of Open Access Journals (Sweden)

    F. Hase

    2012-03-01

    Full Text Available We propose an improved monitoring scheme for the instrumental line shape (ILS of high-resolution, ground-based FTIR (Fourier Transform InfraRed spectrometers used for chemical monitoring of the atmosphere by the Network for Detection of Atmospheric Composition Change (NDACC. Good ILS knowledge is required for the analysis of the recorded mid-infrared spectra. The new method applies a sequence of measurements using different gas cells instead of a single calibration cell. Three cells are used: cell C1 is a refillable cell offering 200 mm path length and equipped with a pressure gauge (filled with 100 Pa N2O, cells C2 and C3 are sealed cells offering 75 mm path length. C2 is filled with 5 Pa of pure N2O. Cell C3 is filled with 16 Pa N2O in 200 hPa technical air, so provides pressure-broadened N2O lines. We demonstrate that an ILS retrieval using C1 improves significantly the sensitivity of the ILS retrieval over the current calibration cells used in the network, because this cell provides narrow fully saturated N2O lines. The N2O columns derived from C2 and C3 allow the performance of a highly valuable closure experiment: adopting the ILS retrieved from C1, the N2O columns of C2 and C3 are derived. Because N2O is an inert gas, both columns should be constant on long timescales. Apparent changes in the columns would immediately attract attention and indicate either inconsistent ILS results or instrumental problems of other origin. Two different cells are applied for the closure experiment, because the NDACC spectrometers observe both stratospheric and tropospheric gases: C2 mimics signatures of stratospheric gases, whereas C3 mimics signatures of tropospheric gases.

  2. Worlds Beyond: A Strategy for the Detection and Characterization of Exoplanets

    Energy Technology Data Exchange (ETDEWEB)

    Lunine, J; Fischer, D; Hammel, H; Hillenbrand, L; Kasting, J; Laughlin, G; Macintosh, B; Marley, M; Melnick, G; Monet, D; Noecker, C; Peale, S; Quirrenbach, A; Seager, S; Winn, J

    2008-06-02

    This report is a comprehensive study of the search for and study of planets around other stars (exoplanets). The young but maturing field of exoplanets is perhaps one of the most compelling fields of study in science today--both because of the discoveries made to date on giant planets around other stars, and because the detection of planets just like our Earth ('Earth analogs') is at last within reach technologically. In the Report we outline the need for a vigorous research program in exoplanets to understand our place in the cosmos: whether planets like our home Earth are a common or rare outcome of cosmic evolution. The strategy we developed is intended to address the following fundamental questions, in priority order, within three distinct 5-yr long phases, over a 15 year period: (1) What are the physical characteristics of planets in the habitable zones around bright, nearby stars? (2) What is the architecture of planetary systems? (3) When, how and in what environments are planets formed? The Report recommends a two-pronged strategy for the detection and characterization of planets the size of the Earth. For stars much less massive and cooler than our Sun (M-dwarfs), existing ground-based techniques including radial velocity and transit searches, and space-based facilities both existing and under development such as Spitzer and JWST, are adequate for finding and studying planets close to the mass and size of the Earth. Conducted in parallel with the M-dwarf strategy is one for the more challenging observations of the hotter and brighter F, G, and K stars, some of which are very close in properties to our Sun, in which the frequency of Earth-sized planets is assessed with Corot and Kepler, but new space missions are required for detection and study of specific Earth-mass and Earth-sized objects. Our Task Force concludes that the development of a space-based astrometric mission, narrowly-focused to identify specific nearby stars with Earth

  3. TAWS: TABLE ASSISTED WALK STRATEGY IN CLONE ATTACK DETECTION

    Directory of Open Access Journals (Sweden)

    J Sybi Cynthia

    2016-12-01

    Full Text Available Wireless Sensor Networks (WSNs deployed in the destructive atmosphere are susceptible to clone attacks. Clone attack in wireless sensor network is a complicated problem because it deployed in hostile environments, and also the nodes could be physically compromised by an adversary. For valuable clone attack detection, the selection criteria play an important role in the proposed work. In this paper, it has been classified the existing detection schemes regarding device type, detection methodologies, deployment strategies and detection ranges and far explore various proposals in deployment based selection criteria category. And also this paper provides a review of detection methodology based on various clone attack detection techniques. It is also widely agreed that clones should be detected quickly as possible with the best optional. Our work is exploratory in that the proposed algorithm concern with table assisted random walk with horizontal and vertical line, frequent level key change and revokes the duplicate node. Our simulation results show that it is more efficient than the detection criteria in terms of security feature, and in detection rate with high resiliency. Specifically, it concentrates on deployment strategy which includes grid based deployment technique. These all come under the selection criteria for better security performance. Our protocol analytically provides effective and clone attack detection capability of robustness.

  4. Goals, Objectives, and Requirements (GOR) of the Ground-based Nuclear Detonation Detection (GNDD) Team for the Office of Defense Nuclear Nonproliferation Research and Development (DNN R&D)

    Energy Technology Data Exchange (ETDEWEB)

    Casey, Leslie A.

    2014-01-13

    The goal, objectives, and requirements (GOR) presented in this document define a framework for describing research directed specifically by the Ground-based Nuclear Detonation Detection (GNDD) Team of the National Nuclear Security Administration (NNSA). The intent of this document is to provide a communication tool for the GNDD Team with NNSA management and with its stakeholder community. It describes the GNDD expectation that much of the improvement in the proficiency of nuclear explosion monitoring will come from better understanding of the science behind the generation, propagation, recording, and interpretation of seismic, infrasound, hydroacoustic, and radionuclide signals and development of "game-changer" advances in science and technology.

  5. Goals, Objectives, and Requirements (GOR) of the Ground-based Nuclear Detonation Detection (GNDD) Team for the Office of Defense Nuclear Nonproliferation Research and Development (DNN R&D)

    International Nuclear Information System (INIS)

    Casey, Leslie A.

    2014-01-01

    The goal, objectives, and requirements (GOR) presented in this document define a framework for describing research directed specifically by the Ground-based Nuclear Detonation Detection (GNDD) Team of the National Nuclear Security Administration (NNSA). The intent of this document is to provide a communication tool for the GNDD Team with NNSA management and with its stakeholder community. It describes the GNDD expectation that much of the improvement in the proficiency of nuclear explosion monitoring will come from better understanding of the science behind the generation, propagation, recording, and interpretation of seismic, infrasound, hydroacoustic, and radionuclide signals and development of 'game-changer' advances in science and technology.

  6. [Clinical impact of social marketing strategy on breast cancer detection].

    Science.gov (United States)

    Quintana-Vidaurri, Adriana Guadalupe; Santana-Chávez, Luis Alejandro; González-Villalobos, Cynthia Guadalupe

    2013-01-01

    to prove the impact of social marketing strategies in breast cancer detection, taking as a parameter the number of mammographies performed. quasi-experimental research, before and after. Sixty-nine physicians in charge of medical consultation and fourteen nurses were studied for a period of seven months, applying social marketing strategies. The total of mammographies were analyzed using Wilcoxon rank-sum test (p marketing proved to be an adequate strategy, which has an impact on the clinical practice of both physicians and nurses.

  7. Story-telling strategies employed in three Northern Sotho detective ...

    African Journals Online (AJOL)

    A short introduction will be given to the history of literary writing in Northern Sotho until the 1950s when the first example of detective writing appeared in Ramaila's volume of short stories, Molomatsebe. Subsequently, the story-telling strategies used by three Northern Sotho authors, namely Ramaila, Matlala and Lebopa ...

  8. Buruli ulcer in West Africa: Strategies for early detection and ...

    African Journals Online (AJOL)

    Until recently, the definitive treatment involved wide surgical excision. Recent data suggest that antibiotic therapy with rifampin and streptomycin may reduce the extent or prevent excision when initiated during the early phases of the disease. New strategies for BU control are needed, emphasizing early detection and ...

  9. 1999 Leak Detection, Monitoring, and Mitigation Strategy Update

    International Nuclear Information System (INIS)

    OHL, P.C.

    1999-01-01

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

  10. Defeating crypsis: detection and learning of camouflage strategies.

    Directory of Open Access Journals (Sweden)

    Jolyon Troscianko

    Full Text Available Camouflage is perhaps the most widespread defence against predators in nature and an active area of interdisciplinary research. Recent work has aimed to understand what camouflage types exist (e.g. background matching, disruptive, and distractive patterns and their effectiveness. However, work has almost exclusively focused on the efficacy of these strategies in preventing initial detection, despite the fact that predators often encounter the same prey phenotype repeatedly, affording them opportunities to learn to find those prey more effectively. The overall value of a camouflage strategy may, therefore, reflect both its ability to prevent detection by predators and resist predator learning. We conducted four experiments with humans searching for hidden targets of different camouflage types (disruptive, distractive, and background matching of various contrast levels over a series of touch screen trials. As with previous work, disruptive coloration was the most successful method of concealment overall, especially with relatively high contrast patterns, whereas potentially distractive markings were either neutral or costly. However, high contrast patterns incurred faster decreases in detection times over trials compared to other stimuli. In addition, potentially distractive markings were sometimes learnt more slowly than background matching markings, despite being found more readily overall. Finally, learning effects were highly dependent upon the experimental paradigm, including the number of prey types seen and whether subjects encountered targets simultaneously or sequentially. Our results show that the survival advantage of camouflage strategies reflects both their ability to avoid initial detection (sensory mechanisms and predator learning (perceptual mechanisms.

  11. MicroRNA Detection: Current Technology and Research Strategies

    Science.gov (United States)

    Hunt, Eric A.; Broyles, David; Head, Trajen; Deo, Sapna K.

    2015-07-01

    The relatively new field of microRNA (miR) has experienced rapid growth in methodology associated with its detection and bioanalysis as well as with its role in -omics research, clinical diagnostics, and new therapeutic strategies. The breadth of this area of research and the seemingly exponential increase in number of publications on the subject can present scientists new to the field with a daunting amount of information to evaluate. This review aims to provide a collective overview of miR detection methods by relating conventional, established techniques [such as quantitative reverse transcription polymerase chain reaction (RT-qPCR), microarray, and Northern blotting (NB)] and relatively recent advancements [such as next-generation sequencing (NGS), highly sensitive biosensors, and computational prediction of microRNA/targets] to common miR research strategies. This should guide interested readers toward a more focused study of miR research and the surrounding technology.

  12. Detection of Multidecadal Changes in UVB and Total Ozone Concentrations over the Continental US with NASA TOMS Data and USDA Ground-Based Measurements

    Directory of Open Access Journals (Sweden)

    Wei Gao

    2010-01-01

    Full Text Available Thinning of the atmospheric ozone layer leads to elevated levels of Ultraviolet-B (UVB at the Earth's surface, resulting in an increase of health risks to living organisms due to DNA damage. This paper examines the multidecadal changes of total column ozone from 1979 to 2005 with the aid of ground-based UVB stations using the ultraviolet multifilter rotating shadow-band radiometer (UV-MFRSR. For the purpose of demonstration, four USDA ground stations, WA01, CO01, MD01, and AZ01, were selected for detailed comparisons against the satellite data. The major finding of this study is that over the course of the time series, on a monthly scale, the UV index (UVI has increased at the four selected USDA stations while total ozone has decreased in the continental USA over the past three decades and spatial distributions of UVI and total ozone have shown substantial variations from coastal zones to the Midwest Regions of the USA, yet the tendency toward recovery of ozone layer in the continental USA cannot be fully confirmed. This leads to a conclusion that the UVI changes might have been influenced by other factors in addition to the total ozone in the atmospheric environment across at least 76% of the continental USA.

  13. A strategy to study regional hydrology and terrestrial ecosystem processes using satellite remote sensing, ground-based data and computer modeling

    Science.gov (United States)

    Vorosmarty, C.; Grace, A.; Moore, B.; Choudhury, B.; Willmott, C. J.

    1990-01-01

    A strategy is presented for integrating scanning multichannel microwave radiometer data from the Nimbus-7 satellite with meteorological station records and computer simulations of land surface hydrology, terrestrial nutrient cycling, and trace gas emission. Analysis of the observations together with radiative transfer analysis shows that in the tropics the temporal and spatial variations of the polarization difference are determined primarily by the structure and phenology of vegetation and seasonal inundations of major rivers and wetlands. It is concluded that the proposed surface hydrology model, along with climatological records, and, potentially, 37-GHz data for phenology, will provide inputs to a terrestrial ecosystem model that predicts regional net primary production and CO2 gas exchange.

  14. Event-based progression detection strategies using scanning laser polarimetry images of the human retina

    NARCIS (Netherlands)

    Vermeer, K. A.; Lo, B.; Zhou, Q.; Vos, F. M.; Vossepoel, A. M.; Lemij, H. G.

    2011-01-01

    Monitoring glaucoma patients and ensuring optimal treatment requires accurate and precise detection of progression. Many glaucomatous progression detection strategies may be formulated for Scanning Laser Polarimetry (SLP) data of the local nerve fiber thickness. In this paper, several strategies,

  15. A Ground-Based Direct Detection 1.6μm DIAL for Measurements of Vertical CO2 Concentration Profiles in the Atmosphere

    Science.gov (United States)

    Nagasawa, C.; Abo, M.; Shibata, Y.; Nagai, T.; Sakai, T.; Tsukamoto, M.; Honda, T.

    2011-12-01

    We have developed the ground-based CO2 1.6 μm differential absorption lidar (DIAL) which consists of the optical parametric generator (OPG) transmitter (10mJ/pulse) that excited by the LD pumped Nd:YAG laser with high repetition rate (500Hz) and the receiving optics that included the multi-telescope and the photomultiplier tubes (PMT) with high quantum efficiency (~8%) operating at the photon counting mode. The multi-telescope system is constructed from the combination of multiple telescopes with 20cm to 60cm diameters for the objective altitude range so that the system can reduce the saturation effect of PMTs. Consequentially, the CO2 concentration profiles from ground to an altitude of 10km have been measured with 200m (at the lower altitude range) and 500m (at the upper altitude range) altitude resolutions with better than 1% standard deviation by using this CO2 DIAL. This CO2 DIAL system can be used as the scanning lidar in the atmospheric boundary layer. We also report the 1.6μm DIAL system that can measure the vertical CO2 concentration and temperature profiles in the atmosphere simultaneously. The value of the retrieved CO2 concentration will be improved remarkably by processing the iteration assignment of the CO2 concentration and temperature profiles measured by the CO2 DIAL techniques and the pressure profiles provided from objective analysis data. The 1.6 μm CO2 DIAL system is available to measure the vertical CO2 concentration profiles for nighttime and daytime using the specially designed narrow band interference filter (bandwidth:0.5nm) and the narrow field of view of the receiving telescope. This work was financially supported by the System Development Program for Advanced Measurement and Analysis of the Japan Science and Technology Agency. Reference D. Sakaisawa, C. Nagasawa, T. Nagai, M. Abo, Y. Shibata, H. Nagai, M. Nakazato, and T. Sakai, Development of a 1.6μm differential absorption lidar with a quasi-phase-matching optical parametric

  16. Ground-Based Radar Detection of the Inner Boundary of the Ion Plasma Sheet and its Response to the Changes in the Interplanetary Magnetic Field

    National Research Council Canada - National Science Library

    Jayachandran, P. T; MacDougall, J. W; Moorcroft, D. R; Donovan, E. F

    2006-01-01

    ...-I). Wide area coverage made it possible to detect some of the proxies for the magnetospheric land marks and boundaries on a global scale and shed some light on the on the some of the fundamental problems...

  17. Genetically modified crops: detection strategies and biosafety issues.

    Science.gov (United States)

    Kamle, Suchitra; Ali, Sher

    2013-06-15

    Genetically modified (GM) crops are increasingly gaining acceptance but concurrently consumers' concerns are also increasing. The introduction of Bacillus thuringiensis (Bt) genes into the plants has raised issues related to its risk assessment and biosafety. The International Regulations and the Codex guidelines regulate the biosafety requirements of the GM crops. In addition, these bodies synergize and harmonize the ethical issues related to the release and use of GM products. The labeling of GM crops and their products are mandatory if the genetically modified organism (GMO) content exceeds the levels of a recommended threshold. The new and upcoming GM crops carrying multiple stacked traits likely to be commercialized soon warrant sensitive detection methods both at the DNA and protein levels. Therefore, traceability of the transgene and its protein expression in GM crops is an important issue that needs to be addressed on a priority basis. The advancement in the area of molecular biology has made available several bioanalytical options for the detection of GM crops based on DNA and protein markers. Since the insertion of a gene into the host genome may even cause copy number variation, this may be uncovered using real time PCR. Besides, assessing the exact number of mRNA transcripts of a gene, correlation between the template activity and expressed protein may be established. Here, we present an overview on the production of GM crops, their acceptabilities, detection strategies, biosafety issues and potential impact on society. Further, overall future prospects are also highlighted. Copyright © 2013 Elsevier B.V. All rights reserved.

  18. Analytical strategies to detect enobosarm administration in bovines.

    Science.gov (United States)

    Cesbron, Nora; Sydor, Alexandre; Penot, Mylène; Prevost, Stéphanie; Le Bizec, Bruno; Dervilly-Pinel, Gaud

    2017-04-01

    Selective androgen receptor modulators (SARMs) are a novel class of androgen receptor ligands. They are intended to exhibit the same kind of effects as androgenic drugs, like anabolic steroids, but be much more selective in their action, targeting particular tissues without any undesirable effects on others. While the main applications of these synthetic substances are for therapeutic purposes, they also have a high potential for misuse in veterinary practice and the sporting world. In order to guarantee for consumers with food from animal origin that it is free from any residues of such compounds, analytical strategies are required to ensure safe food and also to enable fair trade between producers. In this context an animal experiment involving bovines administered with enobosarm was conducted to provide the study with biological matrices. Different animal matrices (urine and faeces) were investigated to select the most appropriate matrix for use for control purposes, in terms of metabolite relevance and detection time window. Based on ultra-high-pressure liquid chromatography (UHPLC) with tandem mass spectrometry (LC-MS/MS) this work highlighted the presence of sulfonated and glucuronated-conjugated forms of the molecule in the urine of treated animals. Enobosarm could be detected in urine up to 9 days after the administration when samples underwent phase II hydrolysis. Faeces was demonstrated to be the main matrix of excretion of enobosarm since values up to 500 times higher compared with urine could be detected for 21 days. There was no difference between the kinetic profiles when a deconjugation step was or was not was applied.

  19. Towards Improved Airborne Fire Detection Systems Using Beetle Inspired Infrared Detection and Fire Searching Strategies

    Directory of Open Access Journals (Sweden)

    Herbert Bousack

    2015-06-01

    Full Text Available Every year forest fires cause severe financial losses in many countries of the world. Additionally, lives of humans as well as of countless animals are often lost. Due to global warming, the problem of wildfires is getting out of control; hence, the burning of thousands of hectares is obviously increasing. Most important, therefore, is the early detection of an emerging fire before its intensity becomes too high. More than ever, a need for early warning systems capable of detecting small fires from distances as large as possible exists. A look to nature shows that pyrophilous “fire beetles” of the genus Melanophila can be regarded as natural airborne fire detection systems because their larvae can only develop in the wood of fire-killed trees. There is evidence that Melanophila beetles can detect large fires from distances of more than 100 km by visual and infrared cues. In a biomimetic approach, a concept has been developed to use the surveying strategy of the “fire beetles” for the reliable detection of a smoke plume of a fire from large distances by means of a basal infrared emission zone. Future infrared sensors necessary for this ability are also inspired by the natural infrared receptors of Melanophila beetles.

  20. Detecting local establishment strategies of wild cherry (Prunus avium L.

    Directory of Open Access Journals (Sweden)

    Gregorius Hans-Rolf

    2006-10-01

    Full Text Available Abstract Backround P. avium, a pioneer tree species that colonizes early forest successional stages, is assumed to require an effective strategy allowing stably repeatable rounds of local establishment, dispersal and local extinction. Consequently, the early replacement of cherry by climax tree species makes the establishment of several local generations very unlikely, especially in central European continuous cover forests. This has to be seen in connection with the mixed reproduction system involving asexual reproduction as a complementary adaptational strategy. Tests of the local establishment of wild cherry must therefore consider the possibility of first generation establishment via seedling recruitment potentially followed by an asexual generation (root suckering. Successful establishment can therefore be determined only among adult individuals with the option of detecting vegetative reproduction at these stages. To test the implied suggestion about local establishment strategies of wild cherry, nuclear microsatellites were used to analyse patterns of asexual propagation among adult stages that have been subjected to one of two major types of forest management. These management types, the historical "coppice with standards system" (CWS and the "high forest system" (HFS, can be reasonably assumed to have affected the reproduction system of P. avium. Results Clear differences were found in the reproduction pattern between two stands representing the two forest management types: 1 Clonal propagation is observed in both management systems, but with a distinctly higher frequency in the CWS. Hence, sexual recruitment as a first local generation is followed by a second asexual generation in both, whereas in the CWS there is evidence for an additional clonal generation. 2 The estimation of amounts of clonal reproduction critically depends on the assumptions about multilocus gene associations. This is revealed by the application of newly developed

  1. Section on prospects for dark matter detection of the white paper on the status and future of ground-based TeV gamma-ray astronomy.

    Energy Technology Data Exchange (ETDEWEB)

    Byrum, K.; Horan, D.; Tait, T.; Wanger, R.; Zaharijas, G.; Buckley , J.; Baltz, E. A.; Bertone, G.; Dingus, B.; Fegan, S.; Ferrer, F.; Gondolo, P.; Hall, J.; Hooper, D.; Horan, D.; Koushiappas, S.; Krawczynksi, H.; LeBohec, S.; Pohl, M.; Profumo, S.; Silk , J; Vassilev, V.; Wood , M.; Wakely, S.; High Energy Physics; FNAL; Univ. of St. Louis; Stanford Univ.; Insti. d' Astrophysique; LANL; Univ. of California; Washington Univ.; Univ. of Utah; Brown Univ.; Oxford Univ.; Iowa State Univ.; Univ. of Chicago

    2009-05-13

    This is a report on the findings of the dark matter science working group for the white paper on the status and future of TeV gamma-ray astronomy. The white paper was commissioned by the American Physical Society, and the full white paper can be found on astro-ph (arXiv:0810.0444). This detailed section discusses the prospects for dark matter detection with future gamma-ray experiments, and the complementarity of gamma-ray measurements with other indirect, direct or accelerator-based searches. We conclude that any comprehensive search for dark matter should include gamma-ray observations, both to identify the dark matter particle (through the characteristics of the gamma-ray spectrum) and to measure the distribution of dark matter in galactic halos.

  2. Introduction to a real-time cloud detection based on the ground-based infrared thermometer and the microwave radiometer at ARM SGP site

    Science.gov (United States)

    Won, Hye Young; Ahn, Myoung-Hwan

    2017-04-01

    A fast cloud detection for the utilization of ground based remote sensing instrument such as microwave radiometer is important for the real time application such as assimilation to the numerical prediction model. For this, an algorithm based on the spectral and temporal characteristics of clouds in the downwelling infrared radiance readily available with the infrared thermometer (IRT) equipped in the microwave radiometer has been developed for a specific IRT. Characteristics and applicability of the algorithm for a different types of instrumentation with an augumented validation data are demonstrated using the data obtained at ARM (Atmospheric Radiation Measurement) SGP (the Southern Great Plains) site. From the comparison, it is shown that the dynamic range of IRT (down to -100 oC) is important, while improvement in the spectral test could improve the detectablilty of high thin clouds. For a futher simplification of the algorithm, utilization of the retrieved precipitable water vapor from the microwave radiometer is under investigation and the detailed analysis is going to be presented during the conference.

  3. Microsystem strategies for sample preparation in biological detection.

    Energy Technology Data Exchange (ETDEWEB)

    James, Conrad D.; Galambos, Paul C.; Bennett, Dawn Jonita (University of Maryland Baltimore County, Baltimore, MD); Manginell, Monica; Okandan, Murat; Acrivos, Andreas (The City College of New York, NY); Brozik, Susan Marie; Khusid, Boris (New Jersey Institute of Technology, Newark, NJ)

    2005-03-01

    The objective of this LDRD was to develop microdevice strategies for dealing with samples to be examined in biological detection systems. This includes three sub-components: namely, microdevice fabrication, sample delivery to the microdevice, and sample processing within the microdevice. The first component of this work focused on utilizing Sandia's surface micromachining technology to fabricate small volume (nanoliter) fluidic systems for processing small quantities of biological samples. The next component was to develop interfaces for the surface-micromachined silicon devices. We partnered with Micronics, a commercial company, to produce fluidic manifolds for sample delivery to our silicon devices. Pressure testing was completed to examine the strength of the bond between the pressure-sensitive adhesive layer and the silicon chip. We are also pursuing several other methods, both in house and external, to develop polymer-based fluidic manifolds for packaging silicon-based microfluidic devices. The second component, sample processing, is divided into two sub-tasks: cell collection and cell lysis. Cell collection was achieved using dielectrophoresis, which employs AC fields to collect cells at energized microelectrodes, while rejecting non-cellular particles. Both live and dead Staph. aureus bacteria have been collected using RF frequency dielectrophoresis. Bacteria have been separated from polystyrene microspheres using frequency-shifting dielectrophoresis. Computational modeling was performed to optimize device separation performance, and to predict particle response to the dielectrophoretic traps. Cell lysis is continuing to be pursued using microactuators to mechanically disrupt cell membranes. Novel thermal actuators, which can generate larger forces than previously tested electrostatic actuators, have been incorporated with and tested with cell lysis devices. Significant cell membrane distortion has been observed, but more experiments need to be

  4. Early detection strategies for untreated first-episode psychosis

    DEFF Research Database (Denmark)

    Johannessen, Jan Olav; McGlashan, T H; Larsen, Tor Ketil

    2001-01-01

    Some studies in first-episode schizophrenia correlate shorter duration of untreated psychosis (DUP) with better prognosis, suggesting that timing of treatment may be important. A three-site prospective clinical trial in Norway and Denmark is underway to investigate the effect of the timing...... of treatment in first-episode psychosis. One health care sector (Rogaland, Norway) is experimental and has developed an early detection (ED) system to reduce DUP. Two other sectors (Ullevål, Norway, and Roskilde, Denmark) are comparison sectors and rely on existing detection and referral systems for first......-episode cases. The study ultimately will compare early detected with usual detected patients. This paper describes the study's major independent intervention variable, i.e. a comprehensive education and detection system to change DUP in first onset psychosis. System variables and first results from the four...

  5. Denaturation strategies for detection of double stranded PCR products on GMR magnetic biosensor array

    DEFF Research Database (Denmark)

    Rizzi, Giovanni; Lee, Jung-Rok; Guldberg, Per

    2017-01-01

    Microarrays and other surface-based nucleic acid detection schemes rely on the hybridization of the target to surface-bound detection probes. We present the first comparison of two strategies to detect DNA using a giant magnetoresistive (GMR) biosensor platform starting from an initially double...

  6. Effective sampling strategy to detect food and feed contamination

    NARCIS (Netherlands)

    Bouzembrak, Yamine; Fels, van der Ine

    2018-01-01

    Sampling plans for food safety hazards are aimed to be used to determine whether a lot of food is contaminated (with microbiological or chemical hazards) or not. One of the components of sampling plans is the sampling strategy. The aim of this study was to compare the performance of three

  7. Protein Microarrays-Based Strategies for Life Detection in Astrobiology

    Science.gov (United States)

    Parro, Víctor; Rivas, Luis A.; Gómez-Elvira, Javier

    2008-03-01

    The detection of organic molecules of unambiguous biological origin is fundamental for the confirmation of present or past life. Planetary exploration requires the development of miniaturized apparatus for in situ life detection. Analytical techniques based on mass spectrometry have been traditionally used in space science. Following the Viking landers, gas chromatography-mass spectrometry (GC-MS) for organic detection has gained general acceptance and has been used successfully in the Cassini-Huygens mission to Titan. Microfluidics allows the development of miniaturized capillary electrophoresis devices for the detection of important molecules for life, like amino acids or nucleobases. Recently, a new approach is gaining acceptance in the space science community: the application of the well-known, highly specific, antibody-antigen affinity interaction for the detection and identification of organics and biochemical compounds. Antibodies can specifically bind a plethora of structurally different compounds of a broad range of molecular sizes, from amino acids level to whole cells. Antibody microarray technology allows us to look for the presence of thousands of different compounds in a single assay and in just one square centimeter. Herein, we discuss several important issues—most of which are common with other instruments dealing with life signature detection in the solar system—that must be addressed in order to use antibody microarrays for life detection and planetary exploration. These issues include (1) preservation of biomarkers, (2) the extraction techniques for biomarkers, (3) terrestrial analogues, (4) the antibody stability under space environments, (5) the selection of unequivocal biomarkers for the antibody production, or (6) the instrument design and implementation.

  8. Using trading strategies to detect phase transitions in financial markets

    Science.gov (United States)

    Forró, Z.; Woodard, R.; Sornette, D.

    2015-04-01

    We show that the log-periodic power law singularity model (LPPLS), a mathematical embodiment of positive feedbacks between agents and of their hierarchical dynamical organization, has a significant predictive power in financial markets. We find that LPPLS-based strategies significantly outperform the randomized ones and that they are robust with respect to a large selection of assets and time periods. The dynamics of prices thus markedly deviate from randomness in certain pockets of predictability that can be associated with bubble market regimes. Our hybrid approach, marrying finance with the trading strategies, and critical phenomena with LPPLS, demonstrates that targeting information related to phase transitions enables the forecast of financial bubbles and crashes punctuating the dynamics of prices.

  9. Using trading strategies to detect phase transitions in financial markets.

    Science.gov (United States)

    Forró, Z; Woodard, R; Sornette, D

    2015-04-01

    We show that the log-periodic power law singularity model (LPPLS), a mathematical embodiment of positive feedbacks between agents and of their hierarchical dynamical organization, has a significant predictive power in financial markets. We find that LPPLS-based strategies significantly outperform the randomized ones and that they are robust with respect to a large selection of assets and time periods. The dynamics of prices thus markedly deviate from randomness in certain pockets of predictability that can be associated with bubble market regimes. Our hybrid approach, marrying finance with the trading strategies, and critical phenomena with LPPLS, demonstrates that targeting information related to phase transitions enables the forecast of financial bubbles and crashes punctuating the dynamics of prices.

  10. Plagiarism in the Context of Education and Evolving Detection Strategies.

    Science.gov (United States)

    Gasparyan, Armen Yuri; Nurmashev, Bekaidar; Seksenbayev, Bakhytzhan; Trukhachev, Vladimir I; Kostyukova, Elena I; Kitas, George D

    2017-08-01

    Plagiarism may take place in any scientific journals despite currently employed anti-plagiarism tools. The absence of widely acceptable definitions of research misconduct and reliance solely on similarity checks do not allow journal editors to prevent most complex cases of recycling of scientific information and wasteful, or 'predatory,' publishing. This article analyses Scopus-based publication activity and evidence on poor writing, lack of related training, emerging anti-plagiarism strategies, and new forms of massive wasting of resources by publishing largely recycled items, which evade the 'red flags' of similarity checks. In some non-Anglophone countries 'copy-and-paste' writing still plagues pre- and postgraduate education. Poor research management, absence of courses on publication ethics, and limited access to quality sources confound plagiarism as a cross-cultural and multidisciplinary phenomenon. Over the past decade, the advent of anti-plagiarism software checks has helped uncover elementary forms of textual recycling across journals. But such a tool alone proves inefficient for preventing complex forms of plagiarism. Recent mass retractions of plagiarized articles by reputable open-access journals point to critical deficiencies of current anti-plagiarism software that do not recognize manipulative paraphrasing and editing. Manipulative editing also finds its way to predatory journals, ignoring the adherence to publication ethics and accommodating nonsense plagiarized items. The evolving preventive strategies are increasingly relying on intelligent (semantic) digital technologies, comprehensively evaluating texts, keywords, graphics, and reference lists. It is the right time to enforce adherence to global editorial guidance and implement a comprehensive anti-plagiarism strategy by helping all stakeholders of scholarly communication. © 2017 The Korean Academy of Medical Sciences.

  11. Strategies for the detection of food pathogens and contaminants

    DEFF Research Database (Denmark)

    We routinely use Biacore for affinity ranking and kinetic characterisation of diverse panels of hybridoma-derived and recombinant antibodies against a wide range of different clinically relevant antigens for diagnostic applications. Generally the analytes of interest are haptens or defined protein...... molecules and once suitably high affinity antibodies have been isolated, it is relatively straightforward to design and optimise concentration-based assays using SPR. Recently we have investigated the potential of applying Biacore technology to routine food analysis. Our experiences have shown...... to date with using Biacore for analysis of food contaminants and in particular the challenges associated with large analyte detection...

  12. Strategies for the detection of food pathogens and contaminants

    DEFF Research Database (Denmark)

    Hearty, Stephen; Leonard, Paul; Sheehan, Alfredo Darmanin

    2006-01-01

    We routinely use Biacore for affinity ranking and kinetic characterisation of diverse panels of hybridoma-derived and recombinant antibodies against a wide range of different clinically relevant antigens for diagnostic applications. Generally the analytes of interest are haptens or defined protein...... molecules and once suitably high affinity antibodies have been isolated, it is relatively straightforward to design and optimise concentration-based assays using SPR. Recently we have investigated the potential of applying Biacore technology to routine food analysis. Our experiences have shown...... to date with using Biacore for analysis of food contaminants and in particular the challenges associated with large analyte detection...

  13. Strategies for Testing Statistical and Practical Significance in Detecting DIF with Logistic Regression Models

    Science.gov (United States)

    Fidalgo, Angel M.; Alavi, Seyed Mohammad; Amirian, Seyed Mohammad Reza

    2014-01-01

    This study examines three controversial aspects in differential item functioning (DIF) detection by logistic regression (LR) models: first, the relative effectiveness of different analytical strategies for detecting DIF; second, the suitability of the Wald statistic for determining the statistical significance of the parameters of interest; and…

  14. Strategies for early detection of chronic Q-fever: a systematic review

    NARCIS (Netherlands)

    Wielders, C.C.; Morroy, G.; Wever, P.C.; Coutinho, R.A.; Schneeberger, P.M.; Hoek, W. van der

    2013-01-01

    BACKGROUND: Chronic Q-fever, a condition with high morbidity and mortality, may develop after an acute infection with Coxiella burnetii (acute Q-fever). Several strategies have been suggested for early detection of chronic Q-fever, focusing on follow-up of known acute Q-fever patients and detection

  15. Analytical strategy for detecting doping agents in hair.

    Science.gov (United States)

    Thieme, D; Grosse, J; Sachs, H; Mueller, R K

    2000-01-10

    Lists of banned classes of doping agents are released by the International Olympic Committee, adopted by other sports authorities and updated regularly, including the substance classes stimulants, narcotics, diuretics, anabolic agents, peptide hormones, beta-blockers etc. There are different classes of restriction: anabolic and masking agents (anabolic steroids, diuretics etc.) are always banned for athletes regardless of their topical activity (training or competition) several substances are permitted with certain restrictions (caffeine below a cut-off value, or inhalation of some beta 2 agonists) beta-blockers are prohibited in competitions of certain sports disciplines the majority of the substances (stimulants, narcotics etc.) is prohibited during competitions, so that they do not have to be analysed in out-of-competition samples. A differentiation between training and competition period is impossible by means of hair analysis due to the uncertainty of (especially short-term) kinetic considerations related to hair growth. Therefore, the analytical identification of doping relevant substances in hair is not always a sufficient criterion for a doping offence and the identification of stimulants, beta-blockers etc. in hair would be entirely irrelevant. The most interesting target substances are certainly the anabolic agents, because their desired action (enhanced muscle strength) lasts longer than the excretion, leading to sophisticated procedures to circumvent positive analytical results in competition control. Besides the analysis of out-of-competition control samples, the long term detection of steroids in hair could provide complementary information. An analytical approach to the identification of exogenous steroids in hair requires consideration of the presence of many other steroids in the hair matrix interfering the analysis at trace levels, and of a limited chemical stability. The analysis of endogenous steroids in hair appears to be even more complicated

  16. Novel strategies to enhance lateral flow immunoassay sensitivity for detecting foodborne pathogens.

    Science.gov (United States)

    Shan, Shan; Lai, Weihua; Xiong, Yonghua; Wei, Hua; Xu, Hengyi

    2015-01-28

    Food contaminated by foodborne pathogens causes diseases, affects individuals, and even kills those affected individuals. As such, rapid and sensitive detection methods should be developed to screen pathogens in food. One current detection method is lateral flow immunoassay, an efficient technique because of several advantages, including rapidity, simplicity, stability, portability, and sensitivity. This review presents the format and principle of lateral flow immunoassay strip and the development of conventional lateral flow immunoassay for detecting foodborne pathogens. Furthermore, novel strategies that can be applied to enhance the sensitivity of lateral flow immunoassay to detect foodborne pathogens are presented; these strategies include innovating new label application, designing new formats of lateral flow immunoassay, combining with other methods, and developing signal amplification systems. With these advancements, detection sensitivity and detection time can be greatly improved.

  17. New Strategies for Cultivation and Detection of Previously Uncultured Microbes

    Science.gov (United States)

    Stevenson, Bradley S.; Eichorst, Stephanie A.; Wertz, John T.; Schmidt, Thomas M.; Breznak, John A.

    2004-01-01

    An integrative approach was used to obtain pure cultures of previously uncultivated members of the divisions Acidobacteria and Verrucomicrobia from agricultural soil and from the guts of wood-feeding termites. Some elements of the cultivation procedure included the following: the use of agar media with little or no added nutrients; relatively long periods of incubation (more than 30 days); protection of cells from exogenous peroxides; and inclusion of humic acids or a humic acid analogue (anthraquinone disulfonate) and quorum-signaling compounds (acyl homoserine lactones) in growth media. The bacteria were incubated in the presence of air and in hypoxic (1 to 2% O2 [vol/vol]) and anoxic atmospheres. Some bacteria were incubated with elevated concentrations of CO2 (5% [vol/vol]). Significantly more Acidobacteria were found on isolation plates that had been incubated with 5% CO2. A simple, high-throughput, PCR-based surveillance method (plate wash PCR) was developed. This method greatly facilitated detection and ultimate isolation of target bacteria from as many as 1,000 colonies of nontarget microbes growing on the same agar plates. Results illustrate the power of integrating culture methods with molecular techniques to isolate bacteria from phylogenetic groups underrepresented in culture. PMID:15294811

  18. The Hollywood Strategy for Microlensing Detection of Planets.

    Science.gov (United States)

    Gould, A.

    Follow the big stars! I review the theory of detection and parameter measurement of planetary systems by follow-up observations of ongoing microlensing events. Two parameters can generically be measured from the event itself: the planet/star mass ratio, $q$, and the planet/star separation in units of the Einstein ring. I emphasize the advantages of monitoring events with giant-star sources which are brighter (thus easier to monitor) and bigger (thus offering the prospect of measuring an additional parameter from finite-source effects: the proper motion $\\mu$). There is potentially a strong degeneracy between $q$ and $\\mu$. I present a simple analytic representation of this degeneracy. I then describe how it can be broken using accurate single-band photometry from observatories around the world, or optical/infrared photometry from a single site, or preferably both. Both types of observations are underway or will be soon. Monitoring of giant-star events seen toward the bulge is also the best way to determine the content and structure of the inner Galaxy.

  19. Generalized adaptive strategies for edge detection in digital imagery

    Science.gov (United States)

    Sundaram, Ramakrishnan

    1998-10-01

    Edges in digital imagery can be identified from the zero- crossings of Laplacian of Gaussian (LOG) filtered images. Time or frequency-sampled LOG filters have been developed for the detection and localization of edges in digital image data. The image is decomposed into overlapping subblocks and processed in the transform domain. Adaptive algorithms are developed to minimize spurious edge classifications. In order to achieve accurate and efficient implementations, the discrete symmetric cosine transform of the input data is employed in conjunction with adaptive filters. The adaptive selection of the filter coefficients is based on the gradient criterion. For instance, in the case of the frequency-sampled LOG filter, the filter parameter is systemically varied to force the rejection of false or weak edges. In addition, the proposed algorithms easily extend to higher dimensions. This is useful where 3D medical image data containing edge information has been corrupted by noise. This paper employs isotropic and non-isotropic filters to track edges in such images.

  20. Ground-based observations of exoplanet atmospheres

    NARCIS (Netherlands)

    Mooij, Ernst Johan Walter de

    2011-01-01

    This thesis focuses on the properties of exoplanet atmospheres. The results for ground-based near-infrared secondary eclipse observations of three different exoplanets, TrES-3b, HAT-P-1b and WASP-33b, are presented which have been obtained with ground-based telescopes as part of the GROUSE project.

  1. Optimal marker-strategy clinical trial design to detect predictive markers for targeted therapy.

    Science.gov (United States)

    Zang, Yong; Liu, Suyu; Yuan, Ying

    2016-07-01

    In developing targeted therapy, the marker-strategy design (MSD) provides an important approach to evaluate the predictive marker effect. This design first randomizes patients into non-marker-based or marker-based strategies. Patients allocated to the non-marker-based strategy are then further randomized to receive either the standard or targeted treatments, while patients allocated to the marker-based strategy receive treatments based on their marker statuses. Little research has been done on the statistical properties of the MSD, which has led to some widespread misconceptions and placed clinical researchers at high risk of using inefficient designs. In this article, we show that the commonly used between-strategy comparison has low power to detect the predictive effect and is valid only under a restrictive condition that the randomization ratio within the non-marker-based strategy matches the marker prevalence. We propose a Wald test that is generally valid and also uniformly more powerful than the between-strategy comparison. Based on that, we derive an optimal MSD that maximizes the power to detect the predictive marker effect by choosing the optimal randomization ratios between the two strategies and treatments. Our numerical study shows that using the proposed optimal designs can substantially improve the power of the MSD to detect the predictive marker effect. We use a lung cancer trial to illustrate the proposed optimal designs. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  2. Anabolic agents: recent strategies for their detection and protection from inadvertent doping.

    Science.gov (United States)

    Geyer, Hans; Schänzer, Wilhelm; Thevis, Mario

    2014-05-01

    According to the World Anti-Doping Agency (WADA) Prohibited List, anabolic agents consist of exogenous anabolic androgenic steroids (AAS), endogenous AAS and other anabolic agents such as clenbuterol and selective androgen receptor modulators (SARMs). Currently employed strategies for their improved detection include the prolongation of the detection windows for exogenous AAS, non-targeted and indirect analytical approaches for the detection of modified steroids (designer steroids), the athlete's biological passport and isotope ratio mass spectrometry for the detection of the misuse of endogenous AAS, as well as preventive doping research for the detection of SARMs. The recent use of these strategies led to 4-80-fold increases of adverse analytical findings for exogenous AAS, to the detection of the misuse of new designer steroids, to adverse analytical findings of different endogenous AAS and to the first adverse analytical findings of SARMs. The strategies of the antidoping research are not only focused on the development of methods to catch the cheating athlete but also to protect the clean athlete from inadvertent doping. Within the past few years several sources of inadvertent doping with anabolic agents have been identified. Among these are nutritional supplements adulterated with AAS, meat products contaminated with clenbuterol, mycotoxin (zearalenone) contamination leading to zeranol findings, and natural products containing endogenous AAS. The protection strategy consists of further investigations in case of reasonable suspicion of inadvertent doping, publication of the results, education of athletes and development of methods to differentiate between intentional and unintentional doping.

  3. Evaluating surveillance strategies for the early detection of low pathogenicity avian influenza infections.

    Science.gov (United States)

    Comin, Arianna; Stegeman, Arjan; Marangon, Stefano; Klinkenberg, Don

    2012-01-01

    In recent years, the early detection of low pathogenicity avian influenza (LPAI) viruses in poultry has become increasingly important, given their potential to mutate into highly pathogenic viruses. However, evaluations of LPAI surveillance have mainly focused on prevalence and not on the ability to act as an early warning system. We used a simulation model based on data from Italian LPAI epidemics in turkeys to evaluate different surveillance strategies in terms of their performance as early warning systems. The strategies differed in terms of sample size, sampling frequency, diagnostic tests, and whether or not active surveillance (i.e., routine laboratory testing of farms) was performed, and were also tested under different epidemiological scenarios. We compared surveillance strategies by simulating within-farm outbreaks. The output measures were the proportion of infected farms that are detected and the farm reproduction number (R(h)). The first one provides an indication of the sensitivity of the surveillance system to detect within-farm infections, whereas R(h) reflects the effectiveness of outbreak detection (i.e., if detection occurs soon enough to bring an epidemic under control). Increasing the sampling frequency was the most effective means of improving the timeliness of detection (i.e., it occurs earlier), whereas increasing the sample size increased the likelihood of detection. Surveillance was only effective in preventing an epidemic if actions were taken within two days of sampling. The strategies were not affected by the quality of the diagnostic test, although performing both serological and virological assays increased the sensitivity of active surveillance. Early detection of LPAI outbreaks in turkeys can be achieved by increasing the sampling frequency for active surveillance, though very frequent sampling may not be sustainable in the long term. We suggest that, when no LPAI virus is circulating yet and there is a low risk of virus introduction

  4. Evaluating surveillance strategies for the early detection of low pathogenicity avian influenza infections.

    Directory of Open Access Journals (Sweden)

    Arianna Comin

    Full Text Available In recent years, the early detection of low pathogenicity avian influenza (LPAI viruses in poultry has become increasingly important, given their potential to mutate into highly pathogenic viruses. However, evaluations of LPAI surveillance have mainly focused on prevalence and not on the ability to act as an early warning system. We used a simulation model based on data from Italian LPAI epidemics in turkeys to evaluate different surveillance strategies in terms of their performance as early warning systems. The strategies differed in terms of sample size, sampling frequency, diagnostic tests, and whether or not active surveillance (i.e., routine laboratory testing of farms was performed, and were also tested under different epidemiological scenarios. We compared surveillance strategies by simulating within-farm outbreaks. The output measures were the proportion of infected farms that are detected and the farm reproduction number (R(h. The first one provides an indication of the sensitivity of the surveillance system to detect within-farm infections, whereas R(h reflects the effectiveness of outbreak detection (i.e., if detection occurs soon enough to bring an epidemic under control. Increasing the sampling frequency was the most effective means of improving the timeliness of detection (i.e., it occurs earlier, whereas increasing the sample size increased the likelihood of detection. Surveillance was only effective in preventing an epidemic if actions were taken within two days of sampling. The strategies were not affected by the quality of the diagnostic test, although performing both serological and virological assays increased the sensitivity of active surveillance. Early detection of LPAI outbreaks in turkeys can be achieved by increasing the sampling frequency for active surveillance, though very frequent sampling may not be sustainable in the long term. We suggest that, when no LPAI virus is circulating yet and there is a low risk of virus

  5. Watershed regions and watershed lines based cooperation strategy for image segmentation. Application to roof detection

    OpenAIRE

    EL MERABET, Youssef; MEURIE, Cyril; RUICHEK, Yassine; SBIHI, Abderrahmane; TOUAHNI, Raja

    2011-01-01

    In this paper, we present a strategy of image segmentation for roof detection from aerial images. For that, an orthophotoplan segmentation method based on a cooperation technique including edge based segmentation and region based segmentation is proposed. Both segmentation techniques are assured by watershed algorithm. The proposed strategy is composed of three steps: (i) A simplification step that consists in simplifying the image with an appropriate couple of invariant/gradient optimized fo...

  6. Accelerometer and Camera-Based Strategy for Improved Human Fall Detection

    KAUST Repository

    Zerrouki, Nabil

    2016-10-29

    In this paper, we address the problem of detecting human falls using anomaly detection. Detection and classification of falls are based on accelerometric data and variations in human silhouette shape. First, we use the exponentially weighted moving average (EWMA) monitoring scheme to detect a potential fall in the accelerometric data. We used an EWMA to identify features that correspond with a particular type of fall allowing us to classify falls. Only features corresponding with detected falls were used in the classification phase. A benefit of using a subset of the original data to design classification models minimizes training time and simplifies models. Based on features corresponding to detected falls, we used the support vector machine (SVM) algorithm to distinguish between true falls and fall-like events. We apply this strategy to the publicly available fall detection databases from the university of Rzeszow’s. Results indicated that our strategy accurately detected and classified fall events, suggesting its potential application to early alert mechanisms in the event of fall situations and its capability for classification of detected falls. Comparison of the classification results using the EWMA-based SVM classifier method with those achieved using three commonly used machine learning classifiers, neural network, K-nearest neighbor and naïve Bayes, proved our model superior.

  7. Tank S-102 waste retrieval leak detection and monitoring and mitigation strategy

    International Nuclear Information System (INIS)

    HANSON, C.E.

    2003-01-01

    This paper presents a proactive and mitigative strategy for the identification and management of potential S-102 waste leaks during the S-102 Waste Retrieval and the basis for this approach. The strategy is based on preventing leakage, minimizing leak volumes if a lead should occur, and providing the best available leak detection and monitoring technologies. Ex-tank leak detection will use the baseline borehole gamma and neutron drywell logging trucks, supplemented with manually deployed neutron moisture measurements. Waste mitigation includes management of the retrieval fluids in a manner that limits the risk for a potential leak

  8. Detection of (anti)symmetry and (anti)repetition: perceptual mechanisms versus cognitive strategies.

    Science.gov (United States)

    van der Helm, Peter A; Treder, Matthias S

    2009-11-01

    Symmetry and repetition are recognized as cues in perceptual organization, but there is disagreement on whether they are detected automatically. This disagreement is resolved by noting that some studies mixed up shape regularities and shape antiregularities (i.e., symmetries and repetitions with mismatches in contour curvature polarity). The results of two experiments indicate that a task-irrelevant regularity is automatically picked up by the visual system, whereas a task-irrelevant antiregularity is not. This suggests that detection of regularities is part of the visual system's intrinsic encoding, whereas detection of antiregularities requires higher cognitive strategies involving selective attention.

  9. Development of cost effective fenceline monitoring approaches to support advanced leak detection and repair strategies

    Science.gov (United States)

    Cost-effective fence line and process monitoring systems to support advanced leak detection and repair (LDAR) strategies can enhance protection of public health, facilitate worker safety, and help companies realize cost savings by reducing lost product. The U.S. EPA Office of Re...

  10. Proof-testing strategies induced by dangerous detected failures of safety-instrumented systems

    International Nuclear Information System (INIS)

    Liu, Yiliu; Rausand, Marvin

    2016-01-01

    Some dangerous failures of safety-instrumented systems (SISs) are detected almost immediately by diagnostic self-testing as dangerous detected (DD) failures, whereas other dangerous failures can only be detected by proof-testing, and are therefore called dangerous undetected (DU) failures. Some items may have a DU- and a DD-failure at the same time. After the repair of a DD-failure is completed, the maintenance team has two options: to perform an insert proof test for DU-failure or not. If an insert proof test is performed, it is necessary to decide whether the next scheduled proof test should be postponed or performed at the scheduled time. This paper analyzes the effects of different testing strategies on the safety performance of a single channel of a SIS. The safety performance is analyzed by Petri nets and by approximation formulas and the results obtained by the two approaches are compared. It is shown that insert testing improves the safety performance of the channel, but the feasibility and cost of the strategy may be a hindrance to recommend insert testing. - Highlights: • Identify the tests induced by detected failures. • Model the testing strategies following DD-failures. • Propose analytical formulas for effects of strategies. • Simulate and verify the proposed models.

  11. Prostate cancer detection using machine learning techniques by employing combination of features extracting strategies.

    Science.gov (United States)

    Hussain, Lal; Ahmed, Adeel; Saeed, Sharjil; Rathore, Saima; Awan, Imtiaz Ahmed; Shah, Saeed Arif; Majid, Abdul; Idris, Adnan; Awan, Anees Ahmed

    2018-02-06

    Prostate is a second leading causes of cancer deaths among men. Early detection of cancer can effectively reduce the rate of mortality caused by Prostate cancer. Due to high and multiresolution of MRIs from prostate cancer require a proper diagnostic systems and tools. In the past researchers developed Computer aided diagnosis (CAD) systems that help the radiologist to detect the abnormalities. In this research paper, we have employed novel Machine learning techniques such as Bayesian approach, Support vector machine (SVM) kernels: polynomial, radial base function (RBF) and Gaussian and Decision Tree for detecting prostate cancer. Moreover, different features extracting strategies are proposed to improve the detection performance. The features extracting strategies are based on texture, morphological, scale invariant feature transform (SIFT), and elliptic Fourier descriptors (EFDs) features. The performance was evaluated based on single as well as combination of features using Machine Learning Classification techniques. The Cross validation (Jack-knife k-fold) was performed and performance was evaluated in term of receiver operating curve (ROC) and specificity, sensitivity, Positive predictive value (PPV), negative predictive value (NPV), false positive rate (FPR). Based on single features extracting strategies, SVM Gaussian Kernel gives the highest accuracy of 98.34% with AUC of 0.999. While, using combination of features extracting strategies, SVM Gaussian kernel with texture + morphological, and EFDs + morphological features give the highest accuracy of 99.71% and AUC of 1.00.

  12. A Strategy for Detection of Inconsistency in Evaluation of Essay Type Answers

    Science.gov (United States)

    Shukla, Archana; Chaudhary, Banshi D.

    2014-01-01

    The quality of evaluation of essay type answer books involving multiple evaluators for courses with large number of enrollments is likely to be affected due to heterogeneity in experience, expertise and maturity of evaluators. In this paper, we present a strategy to detect anomalies in evaluation of essay type answers by multiple evaluators based…

  13. Eating Issues and Body Image in Elementary School: Detection and Prevention Strategies for School Counselors

    Science.gov (United States)

    Springer, Sarah I.; Levitt, Dana Heller

    2016-01-01

    Body image disturbance continues to be recognized in increasingly younger populations. Eating issues among elementary school children have become more overt and statistically prevalent in recent years. Elementary school counselors are in important positions to provide their communities with early detection information and prevention strategies.…

  14. Self-organizing control strategy for asteroid intelligent detection swarm based on attraction and repulsion

    Science.gov (United States)

    An, Meiyan; Wang, Zhaokui; Zhang, Yulin

    2017-01-01

    The self-organizing control strategy for asteroid intelligent detection swarm, which is considered as a space application instance of intelligent swarm, is developed. The leader-follower model for the asteroid intelligent detection swarm is established, and the further analysis is conducted for massive asteroid and small asteroid. For a massive asteroid, the leader spacecraft flies under the gravity field of the asteroid. For a small asteroid, the asteroid gravity is negligible, and a trajectory planning method is proposed based on elliptic cavity virtual potential field. The self-organizing control strategy for the follower spacecraft is developed based on a mechanism of velocity planning and velocity tracking. The simulation results show that the self-organizing control strategy is valid for both massive asteroid and small asteroid, and the exploration swarm forms a stable configuration.

  15. Three different signal amplification strategies for the impedimetric sandwich detection of thrombin

    Energy Technology Data Exchange (ETDEWEB)

    Ocaña, Cristina; Valle, Manel del, E-mail: manel.delvalle@uab.cat

    2016-03-17

    In this work, we report a comparative study on three highly specific amplification strategies for the ultrasensitive detection of thrombin with the use of aptamer sandwich protocol. The protocol consisted on the use of a first thrombin aptamer immobilized on the electrode surface, the recognition of thrombin protein, and the reaction with a second biotinylated thrombin aptamer forming the sandwich. Through the exposed biotin end, three variants have been tested to amplify the electrochemical impedance signal. The strategies included (a) silver enhancement treatment, (b) gold enhancement treatment and (c) insoluble product produced by the combination of the enzyme horseradish peroxidase (HRP) and 3-amino-9-ethylcarbazole (AEC). The properties of the sensing surface were probed by electrochemical impedance measurements in the presence of the ferrocyanide/ferricyanide redox marker. Insoluble product strategy and silver enhancement treatment resulted in the lowest detection limit (0.3 pM), while gold enhancement method resulted in the highest reproducibility, 8.8% RSD at the pM thrombin concentration levels. Results of silver and gold enhancement treatment also permitted direct inspection by scanning electron microscopy (SEM). - Highlights: • Aptasensor to detect thrombin reaching the femtomolar level. • Biosensing protocol employs two thrombin aptamers in a sandwich capture scheme. • Use of second biotinylated aptamer allows many amplification and detection variants. • Precipitation reaction provides the highest signal amplification of ca. 3 times. • Double recognition event improves remarkably selectivity for thrombin detection.

  16. Detecting gravitational waves from inspiraling binaries with a network of detectors: Coherent versus coincident strategies

    International Nuclear Information System (INIS)

    Mukhopadhyay, Himan; Dhurandhar, Sanjeev; Sago, Norichika; Tagoshi, Hideyuki; Takahashi, Hirotaka; Kanda, Nobuyuki

    2006-01-01

    We compare two strategies of multidetector detection of compact binary inspiral signals, namely, the coincidence and the coherent. For simplicity we consider here two identical detectors having the same power spectral density of noise, that of initial LIGO, located in the same place and having the same orientation. We consider the cases of independent noise as well as that of correlated noise. The coincident strategy involves separately making two candidate event lists, one for each detector, and from these choosing those pairs of events from the two lists which lie within a suitable parameter window, which then are called coincidence detections. The coherent strategy on the other hand involves combining the data phase coherently, so as to obtain a single network statistic which is then compared with a single threshold. Here we attempt to shed light on the question as to which strategy is better. We compare the performances of the two methods by plotting the receiver operating characteristics (ROC) for the two strategies. Several of the results are obtained analytically in order to gain insight. Further we perform numerical simulations in order to determine certain parameters in the analytic formulae and thus obtain the final complete results. We consider here several cases from the relatively simple to the astrophysically more relevant in order to establish our results. The bottom line is that the coherent strategy although more computationally expensive in general than the coincidence strategy, is superior to the coincidence strategy--considerably less false dismissal probability for the same false alarm probability in the viable false alarm regime

  17. Strategy for Generating Sequence-Defined Aptamer Reagent Sets for Detecting Protein Contaminants in Biotherapeutics.

    Science.gov (United States)

    McGivney, James B; Csordas, Andrew T; Walker, Faye M; Bagley, Elizabeth R; Gruber, Emily M; Mage, Peter L; Casas-Finet, Jose; Nakamoto, Margaret A; Eisenstein, Michael; Larkin, Christopher J; Strouse, Robert J; Soh, H Tom

    2018-03-06

    Biologic drugs are typically manufactured in mammalian host cells, and it is critical from a drug safety and efficacy perspective to detect and remove host cell proteins (HCPs) during production. This is currently achieved with sets of polyclonal antibodies (pAbs), but these suffer from critical shortcomings because their composition is inherently undefined, and they cannot detect nonimmunogenic HCPs. In this work, we report a high-throughput screening and array-based binding characterization strategy that we employed to generate a set of aptamers that overcomes these limitations to achieve sensitive, broad-spectrum detection of HCPs from the widely used Chinese hamster ovary (CHO) cell line. We identified a set of 32 DNA aptamers that achieve better sensitivity than a commercial pAb reagent set and can detect a comparable number of HCPs over a broad range of isoelectric points and sizes. Importantly, these aptamers detect multiple contaminants that are known to be responsible for therapeutic antibody degradation and toxicity in patients. Because HCP aptamer reagents are sequence-defined and chemically synthesized, we believe they may enable safer production of biologic drugs, and this strategy should be broadly applicable for the generation of HCP detection reagents for other cell lines.

  18. Credit Card Fraud Detection: A Realistic Modeling and a Novel Learning Strategy.

    Science.gov (United States)

    Dal Pozzolo, Andrea; Boracchi, Giacomo; Caelen, Olivier; Alippi, Cesare; Bontempi, Gianluca

    2017-09-14

    Detecting frauds in credit card transactions is perhaps one of the best testbeds for computational intelligence algorithms. In fact, this problem involves a number of relevant challenges, namely: concept drift (customers' habits evolve and fraudsters change their strategies over time), class imbalance (genuine transactions far outnumber frauds), and verification latency (only a small set of transactions are timely checked by investigators). However, the vast majority of learning algorithms that have been proposed for fraud detection rely on assumptions that hardly hold in a real-world fraud-detection system (FDS). This lack of realism concerns two main aspects: 1) the way and timing with which supervised information is provided and 2) the measures used to assess fraud-detection performance. This paper has three major contributions. First, we propose, with the help of our industrial partner, a formalization of the fraud-detection problem that realistically describes the operating conditions of FDSs that everyday analyze massive streams of credit card transactions. We also illustrate the most appropriate performance measures to be used for fraud-detection purposes. Second, we design and assess a novel learning strategy that effectively addresses class imbalance, concept drift, and verification latency. Third, in our experiments, we demonstrate the impact of class unbalance and concept drift in a real-world data stream containing more than 75 million transactions, authorized over a time window of three years.

  19. Rapid Detection Strategies for the Global Threat of Zika Virus: Current State, New Hypotheses and Limitations

    Directory of Open Access Journals (Sweden)

    Shruti Shukla

    2016-10-01

    Full Text Available The current scenario regarding the widespread Zika virus (ZIKV has resulted in numerous diagnostic studies, specifically in South America and in locations where there is frequent entry of travelers returning from ZIKV-affected areas, including pregnant women with or without clinical symptoms of ZIKV infection. The World Health Organization, WHO, announced that millions of cases of ZIKV are likely to occur in the United States of America in the near future. This situation has created an alarming public health emergency of international concern requiring the detection of this life-threatening viral candidate due to increased cases of newborn microcephaly associated with ZIKV infection. Hence, this review reports possible methods and strategies for the fast and reliable detection of ZIKV with particular emphasis on current updates, knowledge and new hypotheses that might be helpful for medical professionals in poor and developing countries that urgently need to address this problem. In particular, we emphasize liposome-based biosensors. Although these biosensors are currently among the less popular tools for human disease detection, they have become useful tools for the screening and detection of pathogenic bacteria, fungi and viruses because of their versatile advantageous features compared to other sensing devices. This review summarizes the currently available methods employed for the rapid detection of ZIKV and suggests an innovative approach involving the application of a liposome-based hypothesis for the development of new strategies for ZIKV detection and their use as effective biomedicinal tools.

  20. An evaluation of IASI-NH3 with ground-based Fourier transform infrared spectroscopy measurements

    Directory of Open Access Journals (Sweden)

    E. Dammers

    2016-08-01

    Full Text Available Global distributions of atmospheric ammonia (NH3 measured with satellite instruments such as the Infrared Atmospheric Sounding Interferometer (IASI contain valuable information on NH3 concentrations and variability in regions not yet covered by ground-based instruments. Due to their large spatial coverage and (bi-daily overpasses, the satellite observations have the potential to increase our knowledge of the distribution of NH3 emissions and associated seasonal cycles. However the observations remain poorly validated, with only a handful of available studies often using only surface measurements without any vertical information. In this study, we present the first validation of the IASI-NH3 product using ground-based Fourier transform infrared spectroscopy (FTIR observations. Using a recently developed consistent retrieval strategy, NH3 concentration profiles have been retrieved using observations from nine Network for the Detection of Atmospheric Composition Change (NDACC stations around the world between 2008 and 2015. We demonstrate the importance of strict spatio-temporal collocation criteria for the comparison. Large differences in the regression results are observed for changing intervals of spatial criteria, mostly due to terrain characteristics and the short lifetime of NH3 in the atmosphere. The seasonal variations of both datasets are consistent for most sites. Correlations are found to be high at sites in areas with considerable NH3 levels, whereas correlations are lower at sites with low atmospheric NH3 levels close to the detection limit of the IASI instrument. A combination of the observations from all sites (Nobs = 547 give a mean relative difference of −32.4 ± (56.3 %, a correlation r of 0.8 with a slope of 0.73. These results give an improved estimate of the IASI-NH3 product performance compared to the previous upper-bound estimates (−50 to +100 %.

  1. Face recognition in simulated prosthetic vision: face detection-based image processing strategies.

    Science.gov (United States)

    Wang, Jing; Wu, Xiaobei; Lu, Yanyu; Wu, Hao; Kan, Han; Chai, Xinyu

    2014-08-01

    Given the limited visual percepts elicited by current prosthetic devices, it is essential to optimize image content in order to assist implant wearers to achieve better performance of visual tasks. This study focuses on recognition of familiar faces using simulated prosthetic vision. Combined with region-of-interest (ROI) magnification, three face extraction strategies based on a face detection technique were used: the Viola-Jones face region, the statistical face region (SFR) and the matting face region. These strategies significantly enhanced recognition performance compared to directly lowering resolution (DLR) with Gaussian dots. The inclusion of certain external features, such as hairstyle, was beneficial for face recognition. Given the high recognition accuracy achieved and applicable processing speed, SFR-ROI was the preferred strategy. DLR processing resulted in significant face gender recognition differences (i.e. females were more easily recognized than males), but these differences were not apparent with other strategies. Face detection-based image processing strategies improved visual perception by highlighting useful information. Their use is advisable for face recognition when using low-resolution prosthetic vision. These results provide information for the continued design of image processing modules for use in visual prosthetics, thus maximizing the benefits for future prosthesis wearers.

  2. HIV-1 Tat biosensor: Current development and trends for early detection strategies.

    Science.gov (United States)

    Fatin, M F; Ruslinda, A R; Arshad, M K Md; Tee, K K; Ayub, R M; Hashim, U; Kamarulzaman, A; Gopinath, Subash C B

    2016-04-15

    Human immunodeficiency virus (HIV) has infected almost 35 million people worldwide. Various tests have been developed to detect the presence of HIV during the early stages of the disease in order to reduce the risk of transmission to other humans. The HIV-1 Tat protein is one of the proteins present in HIV that are released abundantly approximately 2-4 weeks after infection. In this review, we have outlined various strategies for detecting the Tat protein, which helps transcribe the virus and enhances replication. Detection strategies presented include immunoassays, biosensors and gene expression, which utilize antibodies or aptamers as common probes to sense the presence of Tat. Alternatively, measuring the levels of gene transcription is a direct method of analysing the HIV gene to confirm the presence of Tat. By detection of the Tat protein, virus transmission can be detected in high-risk individuals in the early stages of the disease to reduce the risk of an HIV pandemic. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Network analysis to detect common strategies in Italian foreign direct investment

    Science.gov (United States)

    De Masi, G.; Giovannetti, G.; Ricchiuti, G.

    2013-03-01

    In this paper we reconstruct and discuss the network of Italian firms investing abroad, exploiting information from complex network analysis. This method, detecting the key nodes of the system (both in terms of firms and countries of destination), allows us to single out the linkages among firms without ex-ante priors. Moreover, through the examination of affiliates’ economic activity, it allows us to highlight different internationalization strategies of “leaders” in different manufacturing sectors.

  4. A carbon nanotubes assisted strategy for insulin detection and insulin proteolysis assay

    Energy Technology Data Exchange (ETDEWEB)

    Wang Ying [Department of Chemistry, Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology, Tsinghua University, Haidian District, Beijing 100084 (China); Li Jinghong, E-mail: jhli@mail.tsinghua.edu.cn [Department of Chemistry, Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology, Tsinghua University, Haidian District, Beijing 100084 (China)

    2009-09-14

    The carbon nanotubes (CNTs) assisted strategy has been proposed for insulin sensing and insulin proteolysis analysis. Experiments demonstrated that this strategy could be used for trace insulin determination with a low detection limit 7.75 ng mL{sup -1} (S/N = 3) and a detection range from 20 ng mL{sup -1} to 400 ng mL{sup -1}. Both biocompatibility and intrinsic conductivity of pristine CNTs enabled them to act an excellent biosensing platform for the realization of direct electrochemistry and electrocatalysis of insulin. Compared with the present methods, the proposed strategy could realize the trace insulin detection without electrode modifications. It is more convenient and simpler than those based on the chemically modified electrodes. This method also made the CNTs as the indicator for insulin proteolysis analysis so that the biological process could be studied by electron microscope, electrochemical methods and digital camera. CNTs obtained after the proteolysis showed the same capabilities as the pristine ones in electrochemical signal enhancement and could participate in the bio-circle repeatedly.

  5. Quantal Response Equilibrium-Based Strategies for Intrusion Detection in WSNs

    Directory of Open Access Journals (Sweden)

    Shigen Shen

    2015-01-01

    Full Text Available This paper is to solve the problem stating that applying Intrusion Detection System (IDS to guarantee security of Wireless Sensor Networks (WSNs is computationally costly for sensor nodes due to their limited resources. For this aim, we obtain optimal strategies to save IDS agents’ power, through Quantal Response Equilibrium (QRE that is more realistic than Nash Equilibrium. A stage Intrusion Detection Game (IDG is formulated to describe interactions between the Attacker and IDS agents. The preference structures of different strategy profiles are analyzed. Upon these structures, the payoff matrix is obtained. As the Attacker and IDS agents interact continually, the stage IDG is extended to a repeated IDG and its payoffs are correspondingly defined. The optimal strategies based on QRE are then obtained. These optimal strategies considering bounded rationality make IDS agents not always be in Defend. Sensor nodes’ power consumed in performing intrusion analyses can thus be saved. Experiment results show that the probabilities of the actions adopted by the Attacker can be predicted and thus the IDS can respond correspondingly to protect WSNs.

  6. JRC GMO-Matrix: a web application to support Genetically Modified Organisms detection strategies.

    Science.gov (United States)

    Angers-Loustau, Alexandre; Petrillo, Mauro; Bonfini, Laura; Gatto, Francesco; Rosa, Sabrina; Patak, Alexandre; Kreysa, Joachim

    2014-12-30

    The polymerase chain reaction (PCR) is the current state of the art technique for DNA-based detection of Genetically Modified Organisms (GMOs). A typical control strategy starts by analyzing a sample for the presence of target sequences (GM-elements) known to be present in many GMOs. Positive findings from this "screening" are then confirmed with GM (event) specific test methods. A reliable knowledge of which GMOs are detected by combinations of GM-detection methods is thus crucial to minimize the verification efforts. In this article, we describe a novel platform that links the information of two unique databases built and maintained by the European Union Reference Laboratory for Genetically Modified Food and Feed (EU-RL GMFF) at the Joint Research Centre (JRC) of the European Commission, one containing the sequence information of known GM-events and the other validated PCR-based detection and identification methods. The new platform compiles in silico determinations of the detection of a wide range of GMOs by the available detection methods using existing scripts that simulate PCR amplification and, when present, probe binding. The correctness of the information has been verified by comparing the in silico conclusions to experimental results for a subset of forty-nine GM events and six methods. The JRC GMO-Matrix is unique for its reliance on DNA sequence data and its flexibility in integrating novel GMOs and new detection methods. Users can mine the database using a set of web interfaces that thus provide a valuable support to GMO control laboratories in planning and evaluating their GMO screening strategies. The platform is accessible at http://gmo-crl.jrc.ec.europa.eu/jrcgmomatrix/ .

  7. Enhanced change detection performance reveals improved strategy use in avid action video game players.

    Science.gov (United States)

    Clark, Kait; Fleck, Mathias S; Mitroff, Stephen R

    2011-01-01

    Recent research has shown that avid action video game players (VGPs) outperform non-video game players (NVGPs) on a variety of attentional and perceptual tasks. However, it remains unknown exactly why and how such differences arise; while some prior research has demonstrated that VGPs' improvements stem from enhanced basic perceptual processes, other work indicates that they can stem from enhanced attentional control. The current experiment used a change-detection task to explore whether top-down strategies can contribute to VGPs' improved abilities. Participants viewed alternating presentations of an image and a modified version of the image and were tasked with detecting and localizing the changed element. Consistent with prior claims of enhanced perceptual abilities, VGPs were able to detect the changes while requiring less exposure to the change than NVGPs. Further analyses revealed this improved change detection performance may result from altered strategy use; VGPs employed broader search patterns when scanning scenes for potential changes. These results complement prior demonstrations of VGPs' enhanced bottom-up perceptual benefits by providing new evidence of VGPs' potentially enhanced top-down strategic benefits. Copyright © 2010 Elsevier B.V. All rights reserved.

  8. Pain and sensory detection threshold response to acupuncture is modulated by coping strategy and acupuncture sensation.

    Science.gov (United States)

    Lee, Jeungchan; Napadow, Vitaly; Park, Kyungmo

    2014-09-01

    Acupuncture has been shown to reduce pain, and acupuncture-induced sensation may be important for this analgesia. In addition, cognitive coping strategies can influence sensory perception. However, the role of coping strategy on acupuncture modulation of pain and sensory thresholds, and the association between acupuncture sensation and these modulatory effects, is currently unknown. Electroacupuncture (EA) was applied at acupoints ST36 and GB39 of 61 healthy adults. Different coping conditions were experimentally designed to form an active coping strategy group (AC group), who thought they could control EA stimulation intensity, and a passive coping strategy group (PC group), who did not think they had such control. Importantly, neither group was actually able to control EA stimulus intensity. Quantitative sensory testing was performed before and after EA, and consisted of vibration (VDT), mechanical (MDT), warm (WDT), and cold (CDT) detection thresholds, and pressure (PPT), mechanical (MPT), heat (HPT) and cold (CPT) pain thresholds. Autonomic measures (e.g. skin conductance response, SCR) were also acquired to quantify physiological response to EA under different coping conditions. Subjects also reported the intensity of any acupuncture-induced sensations. Coping strategy was induced with successful blinding in 58% of AC subjects. Compared to PC, AC showed greater SCR to EA. Under AC, EA reduced PPT and CPT. In the AC group, improved pain and sensory thresholds were correlated with acupuncture sensation (VDTchange vs. MI: r=0.58, CDTchange vs. tingling: r=0.53, CPTchange vs. tingling; r=0.55, CPTchange vs. dull; r=0.55). However, in the PC group, improved sensory thresholds were negatively correlated with acupuncture sensation (CDTchange vs. intensity sensitization: r=-0.52, WDTchange vs. fullness: r=-0.57). Our novel approach was able to successfully induce AC and PC strategies to EA stimulation. The interaction between psychological coping strategy and

  9. Calibration of Ground-based Lidar instrument

    DEFF Research Database (Denmark)

    Villanueva, Héctor; Gómez Arranz, Paula

    This report presents the result of the lidar calibration performed for the given Ground-based Lidar at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement unce...

  10. Perceptual strategies of pigeons to detect a rotational centre--a hint for star compass learning?

    Directory of Open Access Journals (Sweden)

    Bianca Alert

    Full Text Available Birds can rely on a variety of cues for orientation during migration and homing. Celestial rotation provides the key information for the development of a functioning star and/or sun compass. This celestial compass seems to be the primary reference for calibrating the other orientation systems including the magnetic compass. Thus, detection of the celestial rotational axis is crucial for bird orientation. Here, we use operant conditioning to demonstrate that homing pigeons can principally learn to detect a rotational centre in a rotating dot pattern and we examine their behavioural response strategies in a series of experiments. Initially, most pigeons applied a strategy based on local stimulus information such as movement characteristics of single dots. One pigeon seemed to immediately ignore eccentric stationary dots. After special training, all pigeons could shift their attention to more global cues, which implies that pigeons can learn the concept of a rotational axis. In our experiments, the ability to precisely locate the rotational centre was strongly dependent on the rotational velocity of the dot pattern and it crashed at velocities that were still much faster than natural celestial rotation. We therefore suggest that the axis of the very slow, natural, celestial rotation could be perceived by birds through the movement itself, but that a time-delayed pattern comparison should also be considered as a very likely alternative strategy.

  11. Damage detection strategies for aircraft shell-like structures based on propagation guided elastic waves

    International Nuclear Information System (INIS)

    Zak, A; Ostachowicz, W; Krawczuk, M

    2011-01-01

    Damage of aircraft structural elements in any form always present high risks. Failures of these elements can be caused by various reasons including material fatigue or impact leading to damage initiation and growth. Detection of these failures at their earliest stage of development, estimation of their size and location, are one of the most crucial factors for each damage detection method. Structural health monitoring strategies based on propagation of guided elastic waves in structures and wave interaction with damage related discontinuities are very promising tools that offer not only damage detection capabilities, but are also meant to provide precise information about the state of the structures and their remaining lifetime. Because of that various techniques are employed to simulate and mimic the wave-discontinuity interactions. The use of various types of sensors, their networks together with sophisticated contactless measuring techniques are investigated both numerically and experimentally. Certain results of numerical simulations obtained by the use of the spectral finite element method are presented by the authors and related with propagation of guided elastic waves in shell-type aircraft structures. Two types of structures are considered: flat 2D panels with or without stiffeners and 3D shell structures. The applicability of two different damage detection approaches is evaluated in order to detect and localise damage in these structures. Selected results related with the use of laser scanning vibrometry are also presented and discussed by the authors.

  12. A multistage testing strategy for detection of quantitative trait Loci affecting disease resistance in Atlantic salmon.

    Science.gov (United States)

    Moen, Thomas; Fjalestad, Kjersti T; Munck, Hege; Gomez-Raya, Luis

    2004-01-01

    A multistage testing strategy to detect QTL for resistance to infectious salmon anemia (ISA) in Atlantic salmon is proposed. First, genotyping of amplified fragment length polymorphisms (AFLP) and a transmission disequilibrium test (TDT) were carried out using dead offspring from a disease resistance challenge test. Second, AFLP genotyping among survivors followed by a Mendelian segregation test was performed. Third, within-family survival analyses using all offspring were developed and applied to significant TDT markers with Mendelian inheritance. Maximum-likelihood methodology was developed for TDT with dominant markers to exploit linkage disequilibrium within families. The strategy was tested with two full-sib families of Atlantic salmon sired by the same male and consisting of 79 offspring in total. All dead offspring from the two families were typed for 64 primer combinations, resulting in 340 scored markers. There were 26 significant results out of 401 TDTs using dead offspring. In the second stage, only 17 marker families showed Mendelian segregation and were tested in survival analysis. A permutation test was performed for all survival analyses to compute experimentwise P-values. Two markers, aaccac356 and agccta150, were significant at P < 0.05 when accounting for multiple testing in the survival analyses. The proposed strategy might be more powerful than current mapping strategies because it reduces the number of tests to be performed in the last testing stage. PMID:15238533

  13. A windowing and mapping strategy for gear tooth fault detection of a planetary gearbox

    Science.gov (United States)

    Liang, Xihui; Zuo, Ming J.; Liu, Libin

    2016-12-01

    When there is a single cracked tooth in a planet gear, the cracked tooth is enmeshed for very short time duration in comparison to the total time of a full revolution of the planet gear. The fault symptom generated by the single cracked tooth may be very weak. This study aims to develop a windowing and mapping strategy to interpret the vibration signal of a planetary gear at the tooth level. The fault symptoms generated by a single cracked tooth of the planet gear of interest can be extracted. The health condition of the planet gear can be assessed by comparing the differences among the signals of all teeth of the planet gear. The proposed windowing and mapping strategy is tested with both simulated vibration signals and experimental vibration signals. The tooth signals can be successfully decomposed and a single tooth fault on a planet gear can be effectively detected.

  14. An Autonomous Divisive Algorithm for Community Detection Based on Weak Link and Link-Break Strategy

    Directory of Open Access Journals (Sweden)

    Xiaoyu Ding

    2018-01-01

    Full Text Available Divisive algorithms are widely used for community detection. A common strategy of divisive algorithms is to remove the external links which connect different communities so that communities get disconnected from each other. Divisive algorithms have been investigated for several decades but some challenges remain unsolved: (1 how to efficiently identify external links, (2 how to efficiently remove external links, and (3 how to end a divisive algorithm with no help of predefined parameters or community definitions. To overcome these challenges, we introduced a concept of the weak link and autonomous division. The implementation of the proposed divisive algorithm adopts a new link-break strategy similar to a tug-of-war contest, where communities act as contestants and weak links act as breakable ropes. Empirical evaluations on artificial and real-world networks show that the proposed algorithm achieves a better accuracy-efficiency trade-off than some of the latest divisive algorithms.

  15. A new method to detect long term trends of methane (CH4 and nitrous oxide (N2O total columns measured within the NDACC ground-based high resolution solar FTIR network

    Directory of Open Access Journals (Sweden)

    M. Schneider

    2011-07-01

    Full Text Available Total columns measured with the ground-based solar FTIR technique are highly variable in time due to atmospheric chemistry and dynamics in the atmosphere above the measurement station. In this paper, a multiple regression model with anomalies of air pressure, total columns of hydrogen fluoride (HF and carbon monoxide (CO and tropopause height are used to reduce the variability in the methane (CH4 and nitrous oxide (N2O total columns to estimate reliable linear trends with as small uncertainties as possible. The method is developed at the Harestua station (60° N, 11° E, 600 m a.s.l. and used on three other European FTIR stations, i.e. Jungfraujoch (47° N, 8° E, 3600 m a.s.l., Zugspitze (47° N, 11° E, 3000 m a.s.l., and Kiruna (68° N, 20° E, 400 m a.s.l.. Linear CH4 trends between 0.13 ± 0.01-0.25 ± 0.02 % yr−1 were estimated for all stations in the 1996-2009 period. A piecewise model with three separate linear trends, connected at change points, was used to estimate the short term fluctuations in the CH4 total columns. This model shows a growth in 1996–1999 followed by a period of steady state until 2007. From 2007 until 2009 the atmospheric CH4 amount increases between 0.57 ± 0.22–1.15 ± 0.17 % yr−1. Linear N2O trends between 0.19 ± 0.01–0.40 ± 0.02 % yr−1 were estimated for all stations in the 1996-2007 period, here with the strongest trend at Harestua and Kiruna and the lowest at the Alp stations. From the N2O total columns crude tropospheric and stratospheric partial columns were derived, indicating that the observed difference in the N2O trends between the FTIR sites is of stratospheric origin. This agrees well with the N2O measurements by the SMR instrument onboard the Odin satellite showing the highest trends at Harestua, 0.98 ± 0.28 % yr−1, and considerably smaller trends at lower latitudes, 0.27 ± 0.25 % yr−1. The multiple regression model was compared with two other trend methods, the ordinary linear

  16. Augmenting WFIRST Microlensing with a Ground-Based Telescope Network

    Science.gov (United States)

    Zhu, Wei; Gould, Andrew

    2016-06-01

    Augmenting the Wide Field Infrared Survey Telescope (WFIRST) microlensing campaigns with intensive observations from a ground-based network of wide-field survey telescopes would have several major advantages. First, it would enable full two-dimensional (2-D) vector microlens parallax measurements for a substantial fraction of low-mass lenses as well as planetary and binary events that show caustic crossing features. For a significant fraction of the free-floating planet (FFP) events and all caustic-crossing planetary/binary events, these 2-D parallax measurements directly lead to complete solutions (mass, distance, transverse velocity) of the lens object (or lens system). For even more events, the complementary ground-based observations will yield 1-D parallax measurements. Together with the 1-D parallaxes from WFIRST alone, they can probe the entire mass range M > M_Earth. For luminous lenses, such 1-D parallax measurements can be promoted to complete solutions (mass, distance, transverse velocity) by high-resolution imaging. This would provide crucial information not only about the hosts of planets and other lenses, but also enable a much more precise Galactic model. Other benefits of such a survey include improved understanding of binaries (particularly with low mass primaries), and sensitivity to distant ice-giant and gas-giant companions of WFIRST lenses that cannot be detected by WFIRST itself due to its restricted observing windows. Existing ground-based microlensing surveys can be employed if WFIRST is pointed at lower-extinction fields than is currently envisaged. This would come at some cost to the event rate. Therefore the benefits of improved characterization of lenses must be weighed against these costs.

  17. GROUND-BASED TRANSIT OBSERVATIONS OF THE SUPER-EARTH 55 Cnc e

    Energy Technology Data Exchange (ETDEWEB)

    De Mooij, E. J. W. [Astronomy and Astrophysics, University of Toronto, Toronto (Canada); López-Morales, M. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA (United States); Karjalainen, R.; Hrudkova, M. [Isaac Newton Group of Telescopes, La Palma (Spain); Jayawardhana, Ray, E-mail: demooij@astro.utoronto.ca [Physics and Astronomy, York University, Toronto (Canada)

    2014-12-20

    We report the first ground-based detections of the shallow transit of the super-Earth exoplanet 55 Cnc e using a 2 m class telescope. Using differential spectrophotometry, we observed one transit in 2013 and another in 2014, with average spectral resolutions of ∼700 and ∼250, spanning the Johnson BVR photometric bands. We find a white light planet-to-star radius ratio of 0.0190{sub −0.0027}{sup +0.0023} from the 2013 observations and 0.0200{sub −0.0018}{sup +0.0017} from the 2014 observations. The two data sets combined result in a radius ratio of 0.0198{sub −0.0014}{sup +0.0013}. These values are all in agreement with previous space-based results. Scintillation noise in the data prevents us from placing strong constraints on the presence of an extended hydrogen-rich atmosphere. Nevertheless, our detections of 55 Cnc e in transit demonstrate that moderate-sized telescopes on the ground will be capable of routine follow-up observations of super-Earth candidates discovered by the Transiting Exoplanet Survey Satellite around bright stars. We expect it also will be possible to place constraints on the atmospheric characteristics of those planets by devising observational strategies to minimize scintillation noise.

  18. Electrochemical DNA sensor-based strategy for sensitive detection of DNA demethylation and DNA demethylase activity.

    Science.gov (United States)

    Shen, Qingming; Fan, Mengxing; Yang, Yin; Zhang, Hui

    2016-08-31

    DNA demethylation and demethylase activity play important roles in DNA self-repair, and their detection is key to early diagnosis of fatal diseases. Herein, a facile electrochemical DNA (E-DNA) sensor was developed for the sensitive detection of DNA demethylation and demethylase activity based on an enzyme cleavage strategy. The thiol modified hemi-methylated hairpin probe DNA (pDNA) was self-assembled on a Au electrode surface through the formation of AuS bonds. The hemi-methylated pDNA served as the substrate of DNA demethylase (using methyl-CpG-binding domain protein 2 (MBD2) as an example). Following demethylation, the hairpin stem was then recognized and cleaved by BstUI endonuclease. The ferrocene carboxylic acid (FcA)-tagged pDNA strands were released into the buffer solution from the electrode surface, resulting in a significant decrease of electrochemical signal and providing a means to observe DNA demethylation. The activity of DNA demethylase was analyzed in the concentration ranging from 0.5 to 500 ng mL(-1) with a limit of detection as low as 0.17 ng mL(-1). With high specificity and sensitivity, rapid response, and low cost, this simple E-DNA sensor provides a unique platform for the sensitive detection of DNA demethylation, DNA demethylase activity, and related molecular diagnostics and drug screening. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Object-Based Change Detection in Urban Areas: The Effects of Segmentation Strategy, Scale, and Feature Space on Unsupervised Methods

    Directory of Open Access Journals (Sweden)

    Lei Ma

    2016-09-01

    Full Text Available Object-based change detection (OBCD has recently been receiving increasing attention as a result of rapid improvements in the resolution of remote sensing data. However, some OBCD issues relating to the segmentation of high-resolution images remain to be explored. For example, segmentation units derived using different segmentation strategies, segmentation scales, feature space, and change detection methods have rarely been assessed. In this study, we have tested four common unsupervised change detection methods using different segmentation strategies and a series of segmentation scale parameters on two WorldView-2 images of urban areas. We have also evaluated the effect of adding extra textural and Normalized Difference Vegetation Index (NDVI information instead of using only spectral information. Our results indicated that change detection methods performed better at a medium scale than at a fine scale where close to the pixel size. Multivariate Alteration Detection (MAD always outperformed the other methods tested, at the same confidence level. The overall accuracy appeared to benefit from using a two-date segmentation strategy rather than single-date segmentation. Adding textural and NDVI information appeared to reduce detection accuracy, but the magnitude of this reduction was not consistent across the different unsupervised methods and segmentation strategies. We conclude that a two-date segmentation strategy is useful for change detection in high-resolution imagery, but that the optimization of thresholds is critical for unsupervised change detection methods. Advanced methods need be explored that can take advantage of additional textural or other parameters.

  20. Direct Detection of Protein Biomarkers in Human Fluids Using Site-Specific Antibody Immobilization Strategies

    Science.gov (United States)

    Soler, Maria; Estevez, M.-Carmen; Alvarez, Mar; Otte, Marinus A.; Sepulveda, Borja; Lechuga, Laura M.

    2014-01-01

    Design of an optimal surface biofunctionalization still remains an important challenge for the application of biosensors in clinical practice and therapeutic follow-up. Optical biosensors offer real-time monitoring and highly sensitive label-free analysis, along with great potential to be transferred to portable devices. When applied in direct immunoassays, their analytical features depend strongly on the antibody immobilization strategy. A strategy for correct immobilization of antibodies based on the use of ProLinker™ has been evaluated and optimized in terms of sensitivity, selectivity, stability and reproducibility. Special effort has been focused on avoiding antibody manipulation, preventing nonspecific adsorption and obtaining a robust biosurface with regeneration capabilities. ProLinker™-based approach has demonstrated to fulfill those crucial requirements and, in combination with PEG-derivative compounds, has shown encouraging results for direct detection in biological fluids, such as pure urine or diluted serum. Furthermore, we have implemented the ProLinker™ strategy to a novel nanoplasmonic-based biosensor resulting in promising advantages for its application in clinical and biomedical diagnosis. PMID:24481229

  1. Direct Detection of Protein Biomarkers in Human Fluids Using Site-Specific Antibody Immobilization Strategies

    Directory of Open Access Journals (Sweden)

    Maria Soler

    2014-01-01

    Full Text Available Design of an optimal surface biofunctionalization still remains an important challenge for the application of biosensors in clinical practice and therapeutic follow-up. Optical biosensors offer real-time monitoring and highly sensitive label-free analysis, along with great potential to be transferred to portable devices. When applied in direct immunoassays, their analytical features depend strongly on the antibody immobilization strategy. A strategy for correct immobilization of antibodies based on the use of ProLinker™ has been evaluated and optimized in terms of sensitivity, selectivity, stability and reproducibility. Special effort has been focused on avoiding antibody manipulation, preventing nonspecific adsorption and obtaining a robust biosurface with regeneration capabilities. ProLinker™-based approach has demonstrated to fulfill those crucial requirements and, in combination with PEG-derivative compounds, has shown encouraging results for direct detection in biological fluids, such as pure urine or diluted serum. Furthermore, we have implemented the ProLinker™ strategy to a novel nanoplasmonic-based biosensor resulting in promising advantages for its application in clinical and biomedical diagnosis.

  2. Individual differences in attention strategies during detection, fine discrimination, and coarse discrimination

    Science.gov (United States)

    Hecker, Elizabeth A.; Serences, John T.; Srinivasan, Ramesh

    2013-01-01

    Interacting with the environment requires the ability to flexibly direct attention to relevant features. We examined the degree to which individuals attend to visual features within and across Detection, Fine Discrimination, and Coarse Discrimination tasks. Electroencephalographic (EEG) responses were measured to an unattended peripheral flickering (4 or 6 Hz) grating while individuals (n = 33) attended to orientations that were offset by 0°, 10°, 20°, 30°, 40°, and 90° from the orientation of the unattended flicker. These unattended responses may be sensitive to attentional gain at the attended spatial location, since attention to features enhances early visual responses throughout the visual field. We found no significant differences in tuning curves across the three tasks in part due to individual differences in strategies. We sought to characterize individual attention strategies using hierarchical Bayesian modeling, which grouped individuals into families of curves that reflect attention to the physical target orientation (“on-channel”) or away from the target orientation (“off-channel”) or a uniform distribution of attention. The different curves were related to behavioral performance; individuals with “on-channel” curves had lower thresholds than individuals with uniform curves. Individuals with “off-channel” curves during Fine Discrimination additionally had lower thresholds than those assigned to uniform curves, highlighting the perceptual benefits of attending away from the physical target orientation during fine discriminations. Finally, we showed that a subset of individuals with optimal curves (“on-channel”) during Detection also demonstrated optimal curves (“off-channel”) during Fine Discrimination, indicating that a subset of individuals can modulate tuning optimally for detection and discrimination. PMID:23678013

  3. Validation of multiplex PCR strategy for simultaneous detection and identification of methicillin resistant Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Rallapalli S

    2008-01-01

    Full Text Available Multiplex polymerase chain reaction (PCR strategy is described for rapid identification of clinically relevant methicillin resistant Staphylococcus aureus (MRSA that targets mecA and coag ulase genes. In this study, 150 staphylococcal clinical isolates were used that included 40 isolates of MRSA, 55 isolates of methicillin susceptible S. aureus (MSSA, 44 isolates of methicillin susceptible coag ulase negative Staphylococcus spp. (MS-CoNS and 11 isolates of methicillin resistant coag ulase negative Staphylococcus spp. (MR-CoNS. Out of 55 S. aureus strains, three strains demonstrated mecA gene, which appeared to be oxacillin sensitive by disc diffusion. When (MS-CoNS were evaluated, 10 isolates classified as oxacillin sensitive phenotypically, yielded positive results in PCR method. The results for mecA detection by PCR were more consistent with disk susceptibility tests in case of MRSA (100% and MSSA (95% isolates. In contrast to above results with MRSA and MSSA, mecA detection by PCR in MS-CoNS showed less correlation with disk susceptibility tests (77%. The results for coag detection by PCR were consistent with phenotypic tests in all isolates.

  4. False-positive reduction in CAD mass detection using a competitive classification strategy

    International Nuclear Information System (INIS)

    Li Lihua; Zheng Yang; Zhang Lei; Clark, Robert A.

    2001-01-01

    High false-positive (FP) rate remains to be one of the major problems to be solved in CAD study because too many false-positively cued signals will potentially degrade the performance of detecting true-positive regions and increase the call-back rate in CAD environment. In this paper, we proposed a novel classification method for FP reduction, where the conventional 'hard' decision classifier is cascaded with a 'soft' decision classification with the objective to reduce false-positives in the cases with multiple FPs retained after the 'hard' decision classification. The 'soft' classification takes a competitive classification strategy in which only the 'best' ones are selected from the pre-classified suspicious regions as the true mass in each case. A neural network structure is designed to implement the proposed competitive classification. Comparative studies of FP reduction on a database of 79 images by a 'hard' decision classification and a combined 'hard'-'soft' classification method demonstrated the efficiency of the proposed classification strategy. For example, for the high FP sub-database which has only 31.7% of total images but accounts for 63.5% of whole FPs generated in single 'hard' classification, the FPs can be reduced for 56% (from 8.36 to 3.72 per image) by using the proposed method at the cost of 1% TP loss (from 69% to 68%) in whole database, while it can only be reduced for 27% (from 8.36 to 6.08 per image) by simply increasing the threshold of 'hard' classifier with a cost of TP loss as high as 14% (from 69% to 55%). On the average in whole database, the FP reduction by hybrid 'hard'-'soft' classification is 1.58 per image as compared to 1.11 by 'hard' classification at the TP costs described above. Because the cases with high dense tissue are of higher risk of cancer incidence and false-negative detection in mammogram screening, and usually generate more FPs in CAD detection, the method proposed in this paper will be very helpful in improving

  5. Complex background suppression using global-local registration strategy for the detection of small-moving target on moving platform

    Science.gov (United States)

    Zou, Tianhao; Zuo, Zhengrong

    2018-02-01

    Target detection is a very important and basic problem of computer vision and image processing. The most often case we meet in real world is a detection task for a moving-small target on moving platform. The commonly used methods, such as Registration-based suppression, can hardly achieve a desired result. To crack this hard nut, we introduce a Global-local registration based suppression method. Differ from the traditional ones, the proposed Global-local Registration Strategy consider both the global consistency and the local diversity of the background, obtain a better performance than normal background suppression methods. In this paper, we first discussed the features about the small-moving target detection on unstable platform. Then we introduced a new strategy and conducted an experiment to confirm its noisy stability. In the end, we confirmed the background suppression method based on global-local registration strategy has a better perform in moving target detection on moving platform.

  6. Digital mammography: Signal-extraction strategies for computer-aided detection of microcalcifications

    International Nuclear Information System (INIS)

    Chan, H.P.; Doi, K.; Metz, C.E.; Vyborny, C.J.; Lam, K.L.; Schmidt, R.A.

    1987-01-01

    The authors found that the structured background of a mammogram can be removed effectively by either a difference-image technique (using a matched filter in combination with a median filter, a contrast-reversal filter, or a box-rim filter) or a visual response filter alone. Locally adaptive gray-level thresholding and region-growing techniques can then be employed to extract microcalcifications from the processed image. Signals are further distinguished from noise or artifacts by their size, contrast, and clustering properties. The authors studied the dependence of the detectability of microcalcifications on the various signal-extraction strategies. Potential application of the computer-aided system to mammography is assessed by its performance on clinical mammograms

  7. Strategy for Sensitive and Specific Detection of Yersinia pestis in Skeletons of the Black Death Pandemic

    Science.gov (United States)

    Seifert, Lisa; Harbeck, Michaela; Thomas, Astrid; Hoke, Nadja; Zöller, Lothar; Wiechmann, Ingrid; Grupe, Gisela; Scholz, Holger C.; Riehm, Julia M.

    2013-01-01

    Yersinia pestis has been identified as the causative agent of the Black Death pandemic in the 14th century. However, retrospective diagnostics in human skeletons after more than 600 years are critical. We describe a strategy following a modern diagnostic algorithm and working under strict ancient DNA regime for the identification of medieval human plague victims. An initial screening and DNA quantification assay detected the Y. pestis specific pla gene of the high copy number plasmid pPCP1. Results were confirmed by conventional PCR and sequence analysis targeting both Y. pestis specific virulence plasmids pPCP1 and pMT1. All assays were meticulously validated according to human clinical diagnostics requirements (ISO 15189) regarding efficiency, sensitivity, specificity, and limit of detection (LOD). Assay specificity was 100% tested on 41 clinically relevant bacteria and 29 Y. pseudotuberculosis strains as well as for DNA of 22 Y. pestis strains and 30 previously confirmed clinical human plague samples. The optimized LOD was down to 4 gene copies. 29 individuals from three different multiple inhumations were initially assessed as possible victims of the Black Death pandemic. 7 samples (24%) were positive in the pPCP1 specific screening assay. Confirmation through second target pMT1 specific PCR was successful for 4 of the positive individuals (14%). A maximum of 700 and 560 copies per µl aDNA were quantified in two of the samples. Those were positive in all assays including all repetitions, and are candidates for future continuative investigations such as whole genome sequencing. We discuss that all precautions taken here for the work with aDNA are sufficient to prevent external sample contamination and fulfill the criteria of authenticity. With regard to retrospective diagnostics of a human pathogen and the uniqueness of ancient material we strongly recommend using a careful strategy and validated assays as presented in our study. PMID:24069445

  8. Strategy for sensitive and specific detection of Yersinia pestis in skeletons of the black death pandemic.

    Science.gov (United States)

    Seifert, Lisa; Harbeck, Michaela; Thomas, Astrid; Hoke, Nadja; Zöller, Lothar; Wiechmann, Ingrid; Grupe, Gisela; Scholz, Holger C; Riehm, Julia M

    2013-01-01

    Yersinia pestis has been identified as the causative agent of the Black Death pandemic in the 14(th) century. However, retrospective diagnostics in human skeletons after more than 600 years are critical. We describe a strategy following a modern diagnostic algorithm and working under strict ancient DNA regime for the identification of medieval human plague victims. An initial screening and DNA quantification assay detected the Y. pestis specific pla gene of the high copy number plasmid pPCP1. Results were confirmed by conventional PCR and sequence analysis targeting both Y. pestis specific virulence plasmids pPCP1 and pMT1. All assays were meticulously validated according to human clinical diagnostics requirements (ISO 15189) regarding efficiency, sensitivity, specificity, and limit of detection (LOD). Assay specificity was 100% tested on 41 clinically relevant bacteria and 29 Y. pseudotuberculosis strains as well as for DNA of 22 Y. pestis strains and 30 previously confirmed clinical human plague samples. The optimized LOD was down to 4 gene copies. 29 individuals from three different multiple inhumations were initially assessed as possible victims of the Black Death pandemic. 7 samples (24%) were positive in the pPCP1 specific screening assay. Confirmation through second target pMT1 specific PCR was successful for 4 of the positive individuals (14%). A maximum of 700 and 560 copies per µl aDNA were quantified in two of the samples. Those were positive in all assays including all repetitions, and are candidates for future continuative investigations such as whole genome sequencing. We discuss that all precautions taken here for the work with aDNA are sufficient to prevent external sample contamination and fulfill the criteria of authenticity. With regard to retrospective diagnostics of a human pathogen and the uniqueness of ancient material we strongly recommend using a careful strategy and validated assays as presented in our study.

  9. Strategy for sensitive and specific detection of Yersinia pestis in skeletons of the black death pandemic.

    Directory of Open Access Journals (Sweden)

    Lisa Seifert

    Full Text Available Yersinia pestis has been identified as the causative agent of the Black Death pandemic in the 14(th century. However, retrospective diagnostics in human skeletons after more than 600 years are critical. We describe a strategy following a modern diagnostic algorithm and working under strict ancient DNA regime for the identification of medieval human plague victims. An initial screening and DNA quantification assay detected the Y. pestis specific pla gene of the high copy number plasmid pPCP1. Results were confirmed by conventional PCR and sequence analysis targeting both Y. pestis specific virulence plasmids pPCP1 and pMT1. All assays were meticulously validated according to human clinical diagnostics requirements (ISO 15189 regarding efficiency, sensitivity, specificity, and limit of detection (LOD. Assay specificity was 100% tested on 41 clinically relevant bacteria and 29 Y. pseudotuberculosis strains as well as for DNA of 22 Y. pestis strains and 30 previously confirmed clinical human plague samples. The optimized LOD was down to 4 gene copies. 29 individuals from three different multiple inhumations were initially assessed as possible victims of the Black Death pandemic. 7 samples (24% were positive in the pPCP1 specific screening assay. Confirmation through second target pMT1 specific PCR was successful for 4 of the positive individuals (14%. A maximum of 700 and 560 copies per µl aDNA were quantified in two of the samples. Those were positive in all assays including all repetitions, and are candidates for future continuative investigations such as whole genome sequencing. We discuss that all precautions taken here for the work with aDNA are sufficient to prevent external sample contamination and fulfill the criteria of authenticity. With regard to retrospective diagnostics of a human pathogen and the uniqueness of ancient material we strongly recommend using a careful strategy and validated assays as presented in our study.

  10. Calibration of Ground-based Lidar instrument

    DEFF Research Database (Denmark)

    Georgieva Yankova, Ginka; Villanueva, Héctor

    This report presents the result of the lidar calibration performed for the given Ground-based Lidar at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement...... uncertainties provided by measurement standard and corresponding lidar wind speed indications with associated measurement uncertainties. The lidar calibration concerns the 10 minute mean wind speed measurements. The comparison of the lidar measurements of the wind direction with that from wind vanes...

  11. Calibration of Ground-based Lidar instrument

    DEFF Research Database (Denmark)

    Gómez Arranz, Paula; Georgieva Yankova, Ginka

    This report presents the result of a test of a ground-based lidar of other type. The test was performed at DTU’s test site for large wind turbines at Høvsøre, Denmark. The result as an establishment of a relation between the reference wind speed measurements with measurement uncertainties provided...... by measurement standard and corresponding lidar wind speed indications with associated measurement uncertainties. The comparison of the lidar measurements of the wind direction with that from the wind vanes is also given....

  12. Computer-aided detection of breast masses: Four-view strategy for screening mammography

    International Nuclear Information System (INIS)

    Wei Jun; Chan Heangping; Zhou Chuan; Wu Yita; Sahiner, Berkman; Hadjiiski, Lubomir M.; Roubidoux, Marilyn A.; Helvie, Mark A.

    2011-01-01

    . The improvement was found to be statistically significant (p<0.0001) by JAFROC analysis. Conclusions: The four-view information fusion approach that emulates radiologists' reading strategy significantly improves the performance of breast mass detection of the CAD system in comparison with the single-view approach.

  13. What is the best screening strategy to detect advanced colorectal adenomas? Simulation from ongoing Italian screening experiences.

    Science.gov (United States)

    Ventura, Leonardo; Zappa, Marco; Carreras, Giulia; Ciatto, Stefano; Grazzini, Grazia

    2011-01-01

    The best screening strategy for colorectal cancer is still debated. We simulated two screening strategies, namely flexible sigmoidoscopy (single episode) and immunological fecal occult blood test (FOBT) (five biennial rounds) and comparing their results as regards advanced adenomas and colorectal cancer detection. A Markov model was developed to estimate the number of advanced adenomas and colorectal cancer detected with the two compared screening strategies. Two different scenarios, namely a) where the same compliance (50%) at both flexible sigmoidoscopy and immunological FOBT invitation is applied, and b) where the actual compliance observed at a national level (immunological FOBT, 45%; flexible sigmoidoscopy, 30%) is applied. In scenario a), immunological FOBT would detect a total of 20,573 adenomas and 3,952 colorectal cancers, performing 74,507 total colonoscopies compared to 20,939 and 2,511, respectively, detected by flexible sigmoidoscopy, with 17,985 total colonoscopies. In scenario b), immunological FOBT would detect 17,845 advanced adenomas with 65,215 colonoscopies performed compared to 12,672 detected by flexible sigmoidoscopy with 10,796 colonoscopies. The probability of having a colonoscopy for a subject attending all the five immunological FOBT rounds was 15.9%. The simulation suggests that also immunological FOBT screening may achieve a substantial detection of advanced adenomas and therefore may have an impact on colorectal cancer incidence.

  14. Detection of Toxoplasma gondii oocysts in water: proposition of a strategy and evaluation in Champagne-Ardenne Region, France

    Directory of Open Access Journals (Sweden)

    D Aubert

    2009-03-01

    Full Text Available Water is a vehicle for disseminating human and veterinary toxoplasmosis due to oocyst contamination. Several outbreaks of toxoplasmosis throughout the world have been related to contaminated drinking water. We have developed a method for the detection of Toxoplasma gondii oocysts in water and we propose a strategy for the detection of multiple waterborne parasites, including Cryptosporidium spp. and Giardia. Water samples were filtered to recover Toxoplasma oocysts and, after the detection of Cryptosporidium oocysts and Giardia cysts by immunofluorescence, as recommended by French norm procedure NF T 90-455, the samples were purified on a sucrose density gradient. Detection of Toxoplasma was based on PCR amplification and mouse inoculation to determine the presence and infectivity of recovered oocysts. After experimental seeding assays, we determined that the PCR assay was more sensitive than the bioassay. This strategy was then applied to 482 environmental water samples collected since 2001. We detected Toxoplasma DNA in 37 environmental samples (7.7%, including public drinking water; however, none of them were positive by bioassay. This strategy efficiently detects Toxoplasma oocysts in water and may be suitable as a public health sentinel method. Alternative methods can be used in conjunction with this one to determine the infectivity of parasites that were detected by molecular methods.

  15. Proposed strategy for leak detection, monitoring, and mitigation (LDMM) during Hanford single-shell tank waste retrieval

    Energy Technology Data Exchange (ETDEWEB)

    Iwatate, D.F., Westinghouse Hanford

    1996-07-08

    This document proposes a strategy to address issues related to leakage from single-shell tanks (SSTs) during sluicing. A set of criteria are proposed to capture the relevant issues pertaining to leak detection, monitoring, and mitigation (LDMM), and allow DOE-RL, the Contractor, Ecology, and Hanford Stakeholders to reach consensus on allowable leakage volumes (ALVs). Technical studies and findings that support the proposed strategy, and ALV criteria, are summarized and referenced. This document specifically addresses LDMM for SSTs at Hanford, Washington.

  16. Triage strategies in cervical cancer detection in Mexico: methods of the FRIDA Study.

    Science.gov (United States)

    Torres-Ibarra, Leticia; Lazcano-Ponce, Eduardo; Franco, Eduardo L; Cuzick, Jack; Hernández-Ávila, Mauricio; Lorincz, Attila; Rivera, Berenice; Ramírez, Paula; Mendiola-Pastrana, Indira; Rudolph, Samantha E; León-Maldonado, Leith; Hernández, Rubí; Barrios, Elizabeth; Gravitt, Patti; Moscicki, Anna Barbara; Schmeler, Kathleen M; Flores, Yvonne N; Méndez-Hernández, Pablo; Salmerón, Jorge

    2016-04-01

    This paper describes the study design and baseline characteristics of the study population, including the first 30 829 women who enrolled in the Forwarding Research for Improved Detection and Access for Cervical Cancer Screening and Triage (FRIDA Study). This is a large population based study that is evaluating the performance and cost-effectiveness of different triage strategies for high-risk HPV (hrHPV) positive women in Mexico. The target population is more than 100 000 women aged 30 to 64 years who attend the Cervical Cancer Screening Program in 100 health centers in the state of Tlaxcala, Mexico. Since August 2013, all women in the region have been invited to enroll in the study. The study participants are evaluated to determine hrHPV infection using the Cobas 4800 HPV test. The HPV-16/18 genotyping and cytology triage strategies are performed as reflex tests in all hrHPV-positive participants. Women with a positive HPV-16/18 test and/or abnormal cytology (atypical squamous cells of undetermined significance or worse, ASCUS+) are referred for colposcopy evaluation, where a minimum of four biopsies and an endocervical sample are systematically collected. Histologic confirmation is performed by a standardized panel of pathologists. Among the 30 829 women who have been screened, the overall prevalence of hrHPV is 11.0%. The overall prevalence of HPV16 and HPV18 are 1.5% and 0.7%, respectively. Cytological abnormalities (ASCUS+) were detected in 11.8% of the hrHPV-positive women. A total of 27.0% (920/3,401) of the hrHPV-positive women were referred to colposcopy because of a positive HPV16/18 test and/or abnormal reflex cytology, (31.6% had only ASCUS+, 53.6% were HPV16/18 positive with a normal cytology result, and 9.5% were positive to both triage tests). The results of this study will help policy makers and health service providers establish the best practices for triage in cervical cancer screening in Mexico and other countries.

  17. Cyber attack analysis on cyber-physical systems: Detectability, severity, and attenuation strategy

    Science.gov (United States)

    Kwon, Cheolhyeon

    Security of Cyber-Physical Systems (CPS) against malicious cyber attacks is an important yet challenging problem. Since most cyber attacks happen in erratic ways, it is usually intractable to describe and diagnose them systematically. Motivated by such difficulties, this thesis presents a set of theories and algorithms for a cyber-secure architecture of the CPS within the control theoretic perspective. Here, instead of identifying a specific cyber attack model, we are focused on analyzing the system's response during cyber attacks. Firstly, we investigate the detectability of the cyber attacks from the system's behavior under cyber attacks. Specifically, we conduct a study on the vulnerabilities in the CPS's monitoring system against the stealthy cyber attack that is carefully designed to avoid being detected by its detection scheme. After classifying three kinds of cyber attacks according to the attacker's ability to compromise the system, we derive the necessary and sufficient conditions under which such stealthy cyber attacks can be designed to cause the unbounded estimation error while not being detected. Then, the analytical design method of the optimal stealthy cyber attack that maximizes the estimation error is developed. The proposed stealthy cyber attack analysis is demonstrated with illustrative examples on Air Traffic Control (ATC) system and Unmanned Aerial Vehicle (UAV) navigation system applications. Secondly, in an attempt to study the CPSs' vulnerabilities in more detail, we further discuss a methodology to identify potential cyber threats inherent in the given CPSs and quantify the attack severity accordingly. We then develop an analytical algorithm to test the behavior of the CPS under various cyber attack combinations. Compared to a numerical approach, the analytical algorithm enables the prediction of the most effective cyber attack combinations without computing the severity of all possible attack combinations, thereby greatly reducing the

  18. Prognostic investigation of galvanic corrosion precursors in aircraft structures and their detection strategy

    Science.gov (United States)

    James, Robin; Kim, Tae Hee; Narayanan, Ram M.

    2017-04-01

    Aluminum alloys have been the dominant materials for aerospace construction in the past fifty years due to their light weight, forming and alloying, and relative low cost in comparison to titanium and composites. However, in recent years, carbon fiber reinforced polymers (CFRPs) and honeycomb materials have been used in aircrafts in the quest to attain lower weight, high temperature resistance, and better fuel efficiency. When these two materials are coupled together, the structural strength of the aircraft is unparalleled, but this comes at a price, namely galvanic corrosion. Previous experimental results have shown that when CFRP composite materials are joined with high strength aluminum alloys (AA7075-T6 or AA2024-T3), galvanic corrosion occurs at the material interfaces, and the aluminum is in greater danger of corroding, particularly since carbon and aluminum are on the opposite ends of the galvanic series. In this paper, we explore the occurrence of the recognizable precursors of galvanic corrosion when CFRP plate is coupled to an aluminum alloy using SS-304 bolts and exposed to environmental degradation, which creates significant concerns for aircraft structural reliability. The galvanic corrosion software package, BEASY, is used to simulate the growth of corrosion in the designed specimen after which a microwave non-destructive testing (NDT) technique is explored to detect corrosion defects that appear at the interface of this galvanic couple. This paper also explores a loaded waveguide technique to determine the dielectric constant of the final corrosion product at the Q-band millimeter-wave frequency range (33-50 GHz), as this can be an invaluable asset in developing early detection strategies.

  19. A Study on the Model of Detecting the Variation of Geomagnetic Intensity Based on an Adapted Motion Strategy

    Directory of Open Access Journals (Sweden)

    Hong Li

    2017-12-01

    Full Text Available By simulating the geomagnetic fields and analyzing thevariation of intensities, this paper presents a model for calculating the objective function ofan Autonomous Underwater Vehicle (AUVgeomagnetic navigation task. By investigating the biologically inspired strategies, the AUV successfullyreachesthe destination duringgeomagnetic navigation without using the priori geomagnetic map. Similar to the pattern of a flatworm, the proposed algorithm relies on a motion pattern to trigger a local searching strategy by detecting the real-time geomagnetic intensity. An adapted strategy is then implemented, which is biased on the specific target. The results show thereliabilityandeffectivenessofthe proposed algorithm.

  20. Novel Detection Strategy To Rapidly Evaluate the Efficacy of Antichlamydial Agents.

    Science.gov (United States)

    Zhang, Yan; Xian, Yuqi; Gao, Leiqiong; Elaasar, Hiba; Wang, Yao; Tauhid, Lamiya; Hua, Ziyu; Shen, Li

    2017-02-01

    Chlamydia trachomatis infections present a major heath burden worldwide. The conventional method used to detect C. trachomatis is laborious. In the present study, a novel strategy was utilized to evaluate the impact of antimicrobial agents on the growth of C. trachomatis and its expression of ompA promoter-driven green fluorescence protein (GFP). We demonstrate that this GFP reporter system gives a robust fluorescent display of C. trachomatis growth in human cervical epithelial cells and, further, that GFP production directly correlates to changes in ompA expression following sufficient exposure to antimicrobials. Validation with azithromycin, the first-line macrolide drug used for the treatment of C. trachomatis infection, highlights the advantages of this method over the traditional method because of its simplicity and versatility. The results indicate both that ompA is highly responsive to antimicrobials targeting the transcription and translation of C. trachomatis and that there is a correlation between changing GFP levels and C. trachomatis growth. This proof-of-concept study also reveals that the ompA-GFP system can be easily adapted to rapidly assess antimicrobial effectiveness in a high-throughput format. Copyright © 2017 American Society for Microbiology.

  1. Microbiological problems in turbine oils - detection on-site, anti-microbial strategies

    Energy Technology Data Exchange (ETDEWEB)

    Hill, E.C. [ECHA Microbiology Ltd., Cardiff (United Kingdom). Unit M210 Cardiff Bay Business Centre

    2008-04-15

    Some microbes can gain access to wet turbine oil systems, and if they find the chemical and physical environment conducive, they will proliferate wherever there is free water. This infected water can be considered as the factory which produces these slimy, sticky, corrosive organisms; their surfactancy allows them to spread into the oil causing operational problems and to colonize other niches. Many will die when they are in dry or hot oil, but they still have the ability to cause fouling. A variety of anti-microbial strategies can be deployed to minimize the risk of operational problems. Considerable care must be used when implementing them, particularly the use of biocides. It is much easier to kill a few microbes than many microbes, and it is sensible to do this before operational problems occur. On-site microbiological test kits are now being used by power station chemists to monitor turbine oils and detect early growth, and to check the efficacy of any remedial measures implemented. (orig.)

  2. A novel immunochromatographic assay based on a time-resolved chemiluminescence strategy for the multiplexed detection of ractopamine and clenbuterol.

    Science.gov (United States)

    Wang, Wenwen; Su, Xiaoxiao; Ouyang, Hui; Wang, Lin; Fu, Zhifeng

    2016-04-21

    A novel multiplexed immunochromatographic assay (ICA) based on a time-resolved chemiluminescence (CL) strategy was developed for quantitative detection of β-agonists, by utilizing ractopamine (RAC) and clenbuterol (CLE) as the models. Different from conventional multiplexed ICA methods which usually require two or more test lines, this strategy was developed for detection of two β-agonists by using only one test line on the nitrocellulose membrane. In this study, horseradish peroxidase and alkaline phosphatase were used as the signal probes to label RAC antibody and CLE antibody, respectively. The two CL reactions with flash type and glow type kinetics characteristics were triggered simultaneously by injecting the coreactants, then the signals for RAC and CLE detections were recorded at 3 s and 300 s after coreactants injection, respectively. Owing to the utilization of CL detection, this protocol showed ideal sensitivity for quantitation. Under the optimal conditions, the detection limits for RAC and CLE were 0.17 ng mL(-1) and 0.067 ng mL(-1) (S/N = 3), respectively. The whole assay process can be accomplished within 20 min without complicated sample pretreatment. The proposed method was successfully applied for the detection of RAC and CLE in spiked swine urine. It opens up a new pathway for designing a low cost, time-efficiency and multiplexed strategy for rapid screening and field assay. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Modelling systematics of ground-based transit photometry I. Implications on transit timing variations

    DEFF Research Database (Denmark)

    von Essen, C.; Cellone, S.; Mallonn, M.

    2016-01-01

    The transit timing variation technique (TTV) has been widely used to detect and characterize multiple planetary systems. Due to the observational biases imposed mainly by the photometric conditions and instrumentation and the high signal-to-noise required to produce primary transit observations...... the observing time at hand carrying out such follow-ups, or if the use of medium-to-low quality transit light curves, combined with current standard techniques of data analysis, could be playing a main role against exoplanetary search via TTVs. The purpose of this work is to investigate to what extent ground......-based observations treated with current modelling techniques are reliable to detect and characterize additional planets in already known planetary systems. To meet this goal, we simulated typical primary transit observations of a hot Jupiter mimicing an existing system, Qatar-1. To resemble ground-based observations...

  4. Multiple Strategy Bio-Detection Sensor Platforms Made from Carbon and Polymer Materials

    National Research Council Canada - National Science Library

    Giedd, Ryan; Ghosh, Kartik; Curry, Matt; Patel, Rishi; Durham, Paul

    2005-01-01

    ...) and a platform that incorporates multiple biodetection strategies. This report discusses the progress to date on the biosensors made from CPMEMS and the multiple strategy biodetection sensor platforms that incorporate these CPMEMS...

  5. Phage-based surface plasmon resonance strategies for the detection of pathogens

    Science.gov (United States)

    Tawil, Nancy

    We start by reviewing the basic principles and recent advances in biosensing technologies using optical, electrochemical and acoustic platforms for phage-based diagnostics. Although much notable work has been done, a low cost, specific, sensitive optical method for detecting low concentrations of pathogens, in a few minutes, has not been established. We conclude from the limited body of work on the subject that improving immobilization strategies and finding more suitable phage recognition elements would allow for a more sensitive approach. Our aim was to better describe the attachment process of MRSA specific phages on gold surfaces, and the subsequent biodetection of their bacterial hosts by surface plasmon resonance (SPR). With the knowledge that the adsorption characteristics of thiol-containing molecules are necessary for applications involving the attachment of recognition elements to a functionalized surface, we start by providing comparative details on the kinetics of self-assembly of L-cysteine and 11-mercaptoundecanoic acid (MUA) monolayers on gold using SPR[1]. Our purpose, in carrying out these measurements was to establish each molecule's validity and applicability as a linker element for use in biosensing. We find that monolayer formation, for both L-cysteine and MUA, is described by the Langmuir isotherm at low concentrations only. For L-cysteine, both the amine and thiol groups contribute to the initial attachment of the molecule, followed by the replacement of the amine-gold complexes initially formed with more stable thiol-gold complexes. The reorganization of L-cysteine creates more space on the gold surface, and the zwitterionic form of the molecule permits the physisorption of a second layer through electrostatic interactions. On the other hand, MUA deposits randomly onto the surface of gold as a SAM and slowly reorganizes into a denser, vertical state. Surface plasmon resonance was then used for the real-time monitoring of the attachment of

  6. Back Translation: An Emerging Sophisticated Cyber Strategy to Subvert Advances in "Digital Age" Plagiarism Detection and Prevention

    Science.gov (United States)

    Jones, Michael; Sheridan, Lynnaire

    2015-01-01

    Advances have been made in detecting and deterring the student plagiarism that has accompanied the uptake and development of the internet. Many authors from the late 1990s onwards grappled with plagiarism in the digital age, presenting articles that were provoking and established the foundation for strategies to address cyber plagiarism, including…

  7. Reconstructing Fire Records from Ground-Based Routine Aerosol Monitoring

    Directory of Open Access Journals (Sweden)

    Hongmei Zhao

    2016-03-01

    Full Text Available Long-term fire records are important to understanding the trend of biomass burning and its interactions with air quality and climate at regional and global scales. Traditionally, such data have been compiled from ground surveys or satellite remote sensing. To obtain aerosol information during a fire event to use in analyzing air quality, we propose a new method of developing a long-term fire record for the contiguous United States using an unconventional data source: ground-based aerosol monitoring. Assisted by satellite fire detection, the mass concentration, size distribution, and chemical composition data of surface aerosols collected from the Interagency Monitoring of Protected Visual Environments (IMPROVE network are examined to identify distinct aerosol characteristics during satellite-detected fire and non-fire periods. During a fire episode, elevated aerosol concentrations and heavy smoke are usually recorded by ground monitors and satellite sensors. Based on the unique physical and chemical characteristics of fire-dominated aerosols reported in the literature, we analyzed the surface aerosol observations from the IMPROVE network during satellite-detected fire events to establish a set of indicators to identify fire events from routine aerosol monitoring data. Five fire identification criteria were chosen: (1 high concentrations of PM2.5 and PM10 (particles smaller than 2.5 and 10 in diameters, respectively; (2 a high PM2.5/PM10 ratio; (3 high organic carbon (OC/PM2.5 and elemental carbon (EC/PM2.5 ratios; (4 a high potassium (K/PM2.5 ratio; and (5 a low soil/PM2.5 ratio. Using these criteria, we are able to identify a number of fire episodes close to 15 IMPROVE monitors from 2001 to 2011. Most of these monitors are located in the Western and Central United States. In any given year within the study period fire events often occurred between April and September, especially in the two months of April and September. This ground-based fire

  8. Strategies for Detecting Hidden Geothermal Systems by Near-Surface Gas Monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Lewicki, Jennifer L.; Oldenburg, Curtis M.

    2004-12-15

    the near-surface environment include (1) the infrared gas analyzer (IRGA) for measurement of concentrations at point locations, (2) the accumulation chamber (AC) method for measuring soil CO2 fluxes at point locations, (3) the eddy covariance (EC) method for measuring net CO2 flux over a given area, (4) hyperspectral imaging of vegetative stress resulting from elevated CO2 concentrations, and (5) light detection and ranging (LIDAR) that can measure CO2 concentrations over an integrated path. Technologies currently in developmental stages that have the potential to be used for CO2 monitoring include tunable lasers for long distance integrated concentration measurements and micro-electronic mechanical systems (MEMS) that can make widespread point measurements. To address the challenge of detecting potentially small-magnitude geothermal CO2 emissions within the natural background variability of CO2, we propose an approach that integrates available detection and monitoring methodologies with statistical analysis and modeling strategies. Within the area targeted for geothermal exploration, point measurements of soil CO2 fluxes and concentrations using the AC method and a portable IRGA, respectively, and measurements of net surface flux using EC should be made. Also, the natural spatial and temporal variability of surface CO2 fluxes and subsurface CO2 concentrations should be quantified within a background area with similar geologic, climatic, and ecosystem characteristics to the area targeted for geothermal exploration. Statistical analyses of data collected from both areas should be used to guide sampling strategy, discern spatial patterns that may be indicative of geothermal CO2 emissions, and assess the presence (or absence) of geothermal CO2 within the natural background variability with a desired confidence level. Once measured CO2 concentrations and fluxes have been determined to be of anomalous geothermal origin with high confidence, more expensive vertical

  9. Rayleigh’s quotient–based damage detection algorithm: Theoretical concepts, computational techniques, and field implementation strategies

    DEFF Research Database (Denmark)

    NJOMO WANDJI, Wilfried

    2017-01-01

    This article proposes a Rayleigh’s quotient–based damage detection algorithm. It aims at efficiently revealing nascent structural changes on a given structure with the capability to differentiate between an actual damage and a change in operational conditions. The first three damage detection lev...... cases and estimated the damage severity with acceptable accuracy. The conclusion is that the proposed algorithm was able to efficiently detect damage appearance in a range of structures for various damage levels and locations, and under different operational conditions.......This article proposes a Rayleigh’s quotient–based damage detection algorithm. It aims at efficiently revealing nascent structural changes on a given structure with the capability to differentiate between an actual damage and a change in operational conditions. The first three damage detection...... optimization methods. Field implementation strategies are also considered for the purpose of online damage monitoring. In order to prove the efficiency of this strategy, one experimental and three numerical case studies were conducted. The proposed algorithm successfully detected the damage in all simulated...

  10. Comparison of Ground-Based and Satellite-Derived Solar UV Index Levels at Six South African Sites.

    Science.gov (United States)

    Cadet, Jean-Maurice; Bencherif, Hassan; Portafaix, Thierry; Lamy, Kévin; Ncongwane, Katlego; Coetzee, Gerrie J R; Wright, Caradee Y

    2017-11-14

    South Africa has been measuring the ground-based solar UV index for more than two decades at six sites to raise awareness about the impacts of the solar UV index on human health. This paper is an exploratory study based on comparison with satellite UV index measurements from the OMI/AURA experiment. Relative UV index differences between ground-based and satellite-derived data ranged from 0 to 45% depending on the site and year. Most of time, these differences appear in winter. Some ground-based stations' data had closer agreement with satellite-derived data. While the ground-based instruments are not intended for long-term trend analysis, they provide UV index information for public awareness instead, with some weak signs suggesting such long-term trends may exist in the ground-based data. The annual cycle, altitude, and latitude effects clearly appear in the UV index data measured in South Africa. This variability must be taken into account for the development of an excess solar UV exposure prevention strategy.

  11. Comparison of Ground-Based and Satellite-Derived Solar UV Index Levels at Six South African Sites

    Directory of Open Access Journals (Sweden)

    Jean-Maurice Cadet

    2017-11-01

    Full Text Available South Africa has been measuring the ground-based solar UV index for more than two decades at six sites to raise awareness about the impacts of the solar UV index on human health. This paper is an exploratory study based on comparison with satellite UV index measurements from the OMI/AURA experiment. Relative UV index differences between ground-based and satellite-derived data ranged from 0 to 45% depending on the site and year. Most of time, these differences appear in winter. Some ground-based stations’ data had closer agreement with satellite-derived data. While the ground-based instruments are not intended for long-term trend analysis, they provide UV index information for public awareness instead, with some weak signs suggesting such long-term trends may exist in the ground-based data. The annual cycle, altitude, and latitude effects clearly appear in the UV index data measured in South Africa. This variability must be taken into account for the development of an excess solar UV exposure prevention strategy.

  12. Proposed strategy for leak detection, monitoring, and mitigation during Hanford single-shell tank waste retrieval

    Energy Technology Data Exchange (ETDEWEB)

    Hertzel, J.S.

    1996-07-18

    The objective of this document is to propose a strategy for addressing applicable LDMM-related criteria in order to determine an allowable leakage volume for SSTs targeted for waste retrieval using sluicing. A strategy is required to work through the individual ALV criterion (and related issues) in a prioritized,orderly, and efficient manner. All components of the strategy are based upon LDMM-related issues, functions and requirements,and technology alternatives.

  13. Quantum dot-DNA aptamer conjugates coupled with capillary electrophoresis: A universal strategy for ratiometric detection of organophosphorus pesticides.

    Science.gov (United States)

    Tang, Tingting; Deng, Jingjing; Zhang, Min; Shi, Guoyue; Zhou, Tianshu

    2016-01-01

    Based on the highly sensitivity and stable-fluorescence of water-soluble CdTe/CdS core-shell quantum dots (QDs) with broad-specificity DNA aptamers, a novel ratiometric detection strategy was proposed for the sensitive detection of organophosphorus pesticides by capillary electrophoresis with laser-induced fluorescence (CE-LIF). The as-prepared QDs were first conjugated with the amino-modified oligonucleotide (AMO) by amidation reaction, which is partial complementary to the DNA aptamer of organophosphorus pesticides. Then QD-labeled AMO (QD-AMO) was incubated with the DNA aptamer to form QD-AMO-aptamer duplex. When the target organophosphorus pesticides were added, they could specifically bind the DNA aptamer, leading to the cleavage of QD-AMO-aptamer duplex, accompany with the release of QD-AMO. As a result, the ratio of peak height between QD-AMO and QD-AMO-aptamer duplex changed in the detection process of CE-LIF. This strategy was subsequently applied for the detection of phorate, profenofos, isocarbophos, and omethoate with the detection limits of 0.20, 0.10, 0.17, and 0.23μM, respectively. This is the first report about using QDs as the signal indicators for organophosphorus pesticides detection based on broad-specificity DNA aptamers by CE-LIF, thus contributing to extend the scope of application of QDs in different fields. The proposed method has great potential to be a universal strategy for rapid detection of aptamer-specific small molecule targets by simply changing the types of aptamer sequences. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Detecting Learning Strategies with Analytics: Links with Self-Reported Measures and Academic Performance

    Science.gov (United States)

    Gaševic, Dragan; Jovanovic, Jelena; Pardo, Abelardo; Dawson, Shane

    2017-01-01

    The use of analytic methods for extracting learning strategies from trace data has attracted considerable attention in the literature. However, there is a paucity of research examining any association between learning strategies extracted from trace data and responses to well-established self-report instruments and performance scores. This paper…

  15. Efficiency of a Strategy for Detecting Back Random Responding on the Personality Assessment Inventory

    Science.gov (United States)

    Morey, Leslie C.; Hopwood, Christopher J.

    2004-01-01

    The efficiency of a new strategy to identify back random responding (BRR) on the Personality Assessment Inventory (L. C. Morey, 1991) was studied using random manipulations of item responses from community (904 adult nonpatients) and clinical (1,079 adult patients) respondents. The strategy involved a comparison of short-form and full-instrument T…

  16. SCIENTIFIC EFFICIENCY OF GROUND-BASED TELESCOPES

    International Nuclear Information System (INIS)

    Abt, Helmut A.

    2012-01-01

    I scanned the six major astronomical journals of 2008 for all 1589 papers that are based on new data obtained from ground-based optical/IR telescopes worldwide. Then I collected data on numbers of papers, citations to them in 3+ years, the most-cited papers, and annual operating costs. These data are assigned to four groups by telescope aperture. For instance, while the papers from telescopes with an aperture >7 m average 1.29 more citations than those with an aperture of 2 to 7 m) telescopes. I wonder why the large telescopes do so relatively poorly and suggest possible reasons. I also found that papers based on archival data, such as the Sloan Digital Sky Survey, produce 10.6% as many papers and 20.6% as many citations as those based on new data. Also, the 577.2 papers based on radio data produced 36.3% as many papers and 33.6% as many citations as the 1589 papers based on optical/IR telescopes.

  17. Enhanced surveillance strategies for detecting and monitoring chronic wasting disease in free-ranging cervids

    Science.gov (United States)

    Walsh, Daniel P.

    2012-01-01

    The purpose of this document is to provide wildlife management agencies with the foundation upon which they can build scientifically rigorous and cost-effective surveillance and monitoring programs for chronic wasting disease (CWD) or refine their existing programs. The first chapter provides an overview of potential demographic and spatial risk factors of susceptible wildlife populations that may be exploited for CWD surveillance and monitoring. The information contained in this chapter explores historic as well as recent developments in our understanding of CWD disease dynamics. It also contains many literature references for readers who may desire a more thorough review of the topics or CWD in general. The second chapter examines methods for enhancing efforts to detect CWD on the landscape where it is not presently known to exist and focuses on the efficiency and cost-effectiveness of the surveillance program. Specifically, it describes the means of exploiting current knowledge of demographic and spatial risk factors, as described in the first chapter, through a two-stage surveillance scheme that utilizes traditional design-based sampling approaches and novel statistical methods to incorporate information about the attributes of the landscape, environment, populations and individual animals into CWD surveillance activities. By accounting for these attributes, efficiencies can be gained and cost-savings can be realized. The final chapter is unique in relation to the first two chapters. Its focus is on designing programs to monitor CWD once it is discovered within a jurisdiction. Unlike the prior chapters that are more detailed or prescriptive, this chapter by design is considerably more general because providing comprehensive direction for creating monitoring programs for jurisdictions without consideration of their monitoring goals, sociopolitical constraints, or their biological systems, is not possible. Therefore, the authors draw upon their collective

  18. A strategy for selective detection based on interferent depleting and redox cycling using the plane-recessed microdisk array electrodes

    International Nuclear Information System (INIS)

    Zhu Feng; Yan Jiawei; Lu Miao; Zhou Yongliang; Yang Yang; Mao Bingwei

    2011-01-01

    Highlights: → A novel strategy based on a combination of interferent depleting and redox cycling is proposed for the plane-recessed microdisk array electrodes. → The strategy break up the restriction of selectively detecting a species that exhibits reversible reaction in a mixture with one that exhibits an irreversible reaction. → The electrodes enhance the current signal by redox cycling. → The electrodes can work regardless of the reversibility of interfering species. - Abstract: The fabrication, characterization and application of the plane-recessed microdisk array electrodes for selective detection are demonstrated. The electrodes, fabricated by lithographic microfabrication technology, are composed of a planar film electrode and a 32 x 32 recessed microdisk array electrode. Different from commonly used redox cycling operating mode for array configurations such as interdigitated array electrodes, a novel strategy based on a combination of interferent depleting and redox cycling is proposed for the electrodes with an appropriate configuration. The planar film electrode (the plane electrode) is used to deplete the interferent in the diffusion layer. The recessed microdisk array electrode (the microdisk array), locating within the diffusion layer of the plane electrode, works for detecting the target analyte in the interferent-depleted diffusion layer. In addition, the microdisk array overcomes the disadvantage of low current signal for a single microelectrode. Moreover, the current signal of the target analyte that undergoes reversible electron transfer can be enhanced due to the redox cycling between the plane electrode and the microdisk array. Based on the above working principle, the plane-recessed microdisk array electrodes break up the restriction of selectively detecting a species that exhibits reversible reaction in a mixture with one that exhibits an irreversible reaction, which is a limitation of single redox cycling operating mode. The

  19. Combined Characterisation of GOME and TOMS Total Ozone Using Ground-Based Observations from the NDSC

    Science.gov (United States)

    Lambert, J.-C.; VanRoozendael, M.; Simon, P. C.; Pommereau, J.-P.; Goutail, F.; Andersen, S. B.; Arlander, D. W.; BuiVan, N. A.; Claude, H.; deLaNoee, J.; hide

    1998-01-01

    Several years of total ozone measured from space by the ERS-2 GOME, the Earth Probe Total Ozone Mapping Spectrometer (TOMS), and the ADEOS TOMS, are compared with high-quality ground-based observations associated with the Network for the Detection of Stratospheric Change (NDSC), over an extended latitude range and a variety of geophysical conditions. The comparisons with each spaceborne sensor are combined altogether for investigating their respective solar zenith angle (SZA) dependence, dispersion, and difference of sensitivity. The space- and ground-based data are found to agree within a few percent on average. However, the analysis highlights for both Global Ozone Monitoring Experiment (GOME) and TOMS several sources of discrepancies, including a dependence on the SZA at high latitudes and internal inconsistencies.

  20. Dual enzyme-free amplification strategy for ultra-sensitive fluorescent detection of bisphenol A in water.

    Science.gov (United States)

    Yun, Wen; Wu, Hong; Chen, Lin; Yang, Lizhu

    2018-08-22

    An ultra-sensitive strategy for bisphenol A (BPA) detection based on dual enzyme-free strategies: hybridization chain reaction (HCR) and enzyme-strand recycling reaction has been developed. The BPA aptamer can form hairpins structure by the partly self-complementary sequence. In the presence of BPA, the released BPA aptamer sequence can trigger the HCR between two hairpins to from a long nicked double-helix DNA. The tails of hairpins on the duplex DNA were closely enough to hybridize with molecular beacon (MB) on the gold nanoparticles (AuNPs) to circularly cleave the loop of MB, leading to a "turn-on" fluorescent signal. This method exhibited high sensitivity for BPA detection in a linear rang from 0.2 to 1000 pM with 0.05 pM of limit of detection. Moreover, it was successfully used for BPA detection in real water samples. Importantly, this method was simple without complex enzymatic procedure and high cost, showing a promising future for on-site detection of BPA in practical application. Copyright © 2018 Elsevier B.V. All rights reserved.

  1. Automated contouring error detection based on supervised geometric attribute distribution models for radiation therapy: A general strategy

    International Nuclear Information System (INIS)

    Chen, Hsin-Chen; Tan, Jun; Dolly, Steven; Kavanaugh, James; Harold Li, H.; Altman, Michael; Gay, Hiram; Thorstad, Wade L.; Mutic, Sasa; Li, Hua; Anastasio, Mark A.; Low, Daniel A.

    2015-01-01

    Purpose: One of the most critical steps in radiation therapy treatment is accurate tumor and critical organ-at-risk (OAR) contouring. Both manual and automated contouring processes are prone to errors and to a large degree of inter- and intraobserver variability. These are often due to the limitations of imaging techniques in visualizing human anatomy as well as to inherent anatomical variability among individuals. Physicians/physicists have to reverify all the radiation therapy contours of every patient before using them for treatment planning, which is tedious, laborious, and still not an error-free process. In this study, the authors developed a general strategy based on novel geometric attribute distribution (GAD) models to automatically detect radiation therapy OAR contouring errors and facilitate the current clinical workflow. Methods: Considering the radiation therapy structures’ geometric attributes (centroid, volume, and shape), the spatial relationship of neighboring structures, as well as anatomical similarity of individual contours among patients, the authors established GAD models to characterize the interstructural centroid and volume variations, and the intrastructural shape variations of each individual structure. The GAD models are scalable and deformable, and constrained by their respective principal attribute variations calculated from training sets with verified OAR contours. A new iterative weighted GAD model-fitting algorithm was developed for contouring error detection. Receiver operating characteristic (ROC) analysis was employed in a unique way to optimize the model parameters to satisfy clinical requirements. A total of forty-four head-and-neck patient cases, each of which includes nine critical OAR contours, were utilized to demonstrate the proposed strategy. Twenty-nine out of these forty-four patient cases were utilized to train the inter- and intrastructural GAD models. These training data and the remaining fifteen testing data sets

  2. Bridge Testing With Ground-Based Interferometric Radar: Experimental Results

    Science.gov (United States)

    Chiara, P.; Morelli, A.

    2010-05-01

    The research of innovative non-contact techniques aimed at the vibration measurement of civil engineering structures (also for damage detection and structural health monitoring) is continuously directed to the optimization of measures and methods. Ground-Based Radar Interferometry (GBRI) represents the more recent technique available for static and dynamic control of structures and ground movements. Dynamic testing of bridges and buildings in operational conditions are currently performed: (a) to assess the conformity of the structure to the project design at the end of construction; (b) to identify the modal parameters (i.e. natural frequencies, mode shapes and damping ratios) and to check the variation of any modal parameters over the years; (c) to evaluate the amplitude of the structural response to special load conditions (i.e. strong winds, earthquakes, heavy railway or roadway loads). If such tests are carried out by using a non-contact technique (like GBRI), the classical issues of contact sensors (like accelerometers) are easily overtaken. This paper presents and discusses the results of various tests carried out on full-scale bridges by using a Stepped Frequency-Continuous Wave radar system.

  3. New Developments in Error Detection and Correction Strategies for Critical Applications

    Science.gov (United States)

    Berg, Melanie; Label, Ken

    2017-01-01

    The presentation will cover a variety of mitigation strategies that were developed for critical applications. An emphasis is placed on strengths and weaknesses per mitigation technique as it pertains to different Field programmable gate array (FPGA) device types.

  4. SU-F-J-197: A Novel Intra-Beam Range Detection and Adaptation Strategy for Particle Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Chen, M; Jiang, S; Shao, Y; Lu, W [UT Southwestern Medical Center, Dallas, TX (United States)

    2016-06-15

    Purpose: In-vivo range detection/verification is crucial in particle therapy for effective and safe delivery. The state-of-art techniques are not sufficient for in-vivo on-line range verification due to conflicts among patient dose, signal statistics and imaging time. We propose a novel intra-beam range detection and adaptation strategy for particle therapy. Methods: This strategy uses the planned mid-range spots as probing beams without adding extra radiation to patients. Such choice of probing beams ensures the Bragg peaks to remain inside the tumor even with significant range variation from the plan. It offers sufficient signal statistics for in-beam positron emission tomography (PET) due to high positron activity of therapeutic dose. The probing beam signal can be acquired and reconstructed using in-beam PET that allows for delineation of the Bragg peaks and detection of range shift with ease of detection enabled by single-layered spots. If the detected range shift is within a pre-defined tolerance, the remaining spots will be delivered as the original plan. Otherwise, a fast re-optimization using range-shifted beamlets and accounting for the probing beam dose is applied to consider the tradeoffs posed by the online anatomy. Simulated planning and delivery studies were used to demonstrate the effectiveness of the proposed techniques. Results: Simulations with online range variations due to shifts of various foreign objects into the beam path showed successful delineation of the Bragg peaks as a result of delivering probing beams. Without on-line delivery adaptation, dose distribution was significantly distorted. In contrast, delivery adaptation incorporating detected range shift recovered well the planned dose. Conclusion: The proposed intra-beam range detection and adaptation utilizing the planned mid-range spots as probing beams, which illuminate the beam range with strong and accurate PET signals, is a safe, practical, yet effective approach to address range

  5. Nest site selection by Kentish plover suggests a trade-off between nest-crypsis and predator detection strategies.

    Directory of Open Access Journals (Sweden)

    Miguel Ángel Gómez-Serrano

    Full Text Available Predation is one of the main causes of adult mortality and breeding failure for ground-nesting birds. Micro-habitat structure around nests plays a critical role in minimizing predation risk. Plovers nest in sites with little vegetation cover to maximize the incubating adult visibility, but many studies suggest a trade-off between nest-crypsis and predator detection strategies. However, this trade-off has not been explored in detail because methods used so far do not allow estimating the visibility with regards to critical factors such as slope or plant permeability to vision. Here, we tested the hypothesis that Kentish plovers select exposed sites according to a predator detection strategy, and the hypothesis that more concealed nests survive longer according to a crypsis strategy. To this end, we obtained an accurate estimation of the incubating adult's field of vision through a custom built inverted periscope. Our results showed that plovers selected nest sites with higher visibility than control points randomly selected with regards to humans and dogs, although nests located in sites with higher vegetation cover survived longer. In addition, the flushing distance (i.e., the distance at which incubating adults leave the nest when they detect a potential predator decreased with vegetation cover. Consequently, the advantages of concealing the nest were limited by the ability to detect predators, thus indirectly supporting the existence of the trade-off between crypsis and predator detection. Finally, human disturbance also constrained nest choice, forcing plovers to move to inland sites that were less suitable because of higher vegetation cover, and modulated flushing behavior, since plovers that were habituated to humans left their nests closer to potential predators. This constraint on the width of suitable breeding habitat is particularly relevant for the conservation of Kentish Plover in sand beaches, especially under the current context of

  6. Cost-effectiveness of MR Imaging-guided Strategies for Detection of Prostate Cancer in Biopsy-Naive Men.

    Science.gov (United States)

    Pahwa, Shivani; Schiltz, Nicholas K; Ponsky, Lee E; Lu, Ziang; Griswold, Mark A; Gulani, Vikas

    2017-10-01

    Purpose To evaluate the cost-effectiveness of multiparametric diagnostic magnetic resonance (MR) imaging examination followed by MR imaging-guided biopsy strategies in the detection of prostate cancer in biopsy-naive men presenting with clinical suspicion of cancer for the first time. Materials and Methods A decision-analysis model was created for biopsy-naive men who had been recommended for prostate biopsy on the basis of abnormal digital rectal examination results or elevated prostate-specific antigen levels (age groups: 41-50 years, 51-60 years, and 61-70 years). The following three major strategies were evaluated: (a) standard transrectal ultrasonography (US)-guided biopsy; (b) diagnostic MR imaging followed by MR imaging-targeted biopsy, with no biopsy performed if MR imaging findings were negative; and (c) diagnostic MR imaging followed by MR imaging-targeted biopsy, with a standard biopsy performed when MR imaging findings were negative. The following three MR imaging-guided biopsy strategies were further evaluated in each MR imaging category: (a) biopsy with cognitive guidance, (b) biopsy with MR imaging/US fusion guidance, and (c) in-gantry MR imaging-guided biopsy. Model parameters were derived from the literature. The primary outcome measure was net health benefit (NHB), which was measured as quality-adjusted life-years (QALYs) gained or lost by investing resources in a new strategy compared with a standard strategy at a willingness-to-pay (WTP) threshold of $50 000 per QALY gained. Probabilistic sensitivity analysis was performed by using Monte Carlo simulations. Results Noncontrast MR imaging followed by cognitively guided MR biopsy (no standard biopsy if MR imaging findings were negative) was the most cost-effective approach, yielding an additional NHB of 0.198 QALY compared with the standard biopsy approach. Noncontrast MR imaging followed by in-gantry MR imaging-guided biopsy (no standard biopsy if MR imaging findings were negative) led to the

  7. Laser-induced fluorescence detection strategies for sodium atoms and compounds in high-pressure combustors

    Science.gov (United States)

    Weiland, Karen J. R.; Wise, Michael L.; Smith, Gregory P.

    1993-01-01

    A variety of laser-induced fluorescence schemes were examined experimentally in atmospheric pressure flames to determine their use for sodium atom and salt detection in high-pressure, optically thick environments. Collisional energy transfer plays a large role in fluorescence detection. Optimum sensitivity, at the parts in 10 exp 9 level for a single laser pulse, was obtained with the excitation of the 4p-3s transition at 330 nm and the detection of the 3d-3p fluorescence at 818 nm. Fluorescence loss processes, such as ionization and amplified spontaneous emission, were examined. A new laser-induced atomization/laser-induced fluorescence detection technique was demonstrated for NaOH and NaCl. A 248-nm excimer laser photodissociates the salt molecules present in the seeded flames prior to atom detection by laser-induced fluorescence.

  8. Ground-based observations of Kepler asteroseismic targets

    DEFF Research Database (Denmark)

    Uyttterhoeven , K.; Karoff, Christoffer

    2010-01-01

    We present the ground-based activities within the different working groups of the Kepler Asteroseismic Science Consortium (KASC). The activities aim at the systematic characterization of the 5000+ KASC targets, and at the collection of ground-based follow-up time-series data of selected promising...... Kepler pulsators. So far, 36 different instruments at 31 telescopes on 23 different observatories in 12 countries are in use, and a total of more than 530 observing nights has been awarded....

  9. Two neural network based strategies for the detection of a total instantaneous blockage of a sodium-cooled fast reactor

    International Nuclear Information System (INIS)

    Martinez-Martinez, Sinuhe; Messai, Nadhir; Jeannot, Jean-Philippe; Nuzillard, Danielle

    2015-01-01

    The total instantaneous blockage (TIB) of an assembly in the core of a sodium-cooled fast reactor (SFR) is investigated. Such incident could appear as an abnormal rise in temperature on the assemblies neighbouring the blockage. Its detection relies on a dataset of temperature measurements of the assemblies making up the core of the French Phenix Nuclear Reactor. The data are provided by the French Commission of Atomic and Alternatives Energies (CEA). Here, two strategies are proposed depending on whether the sensor measurement of the suspected assembly is reliable or not. The proposed methodology implements a time-lagged feed-forward neural (TLFFN) Network in order to predict the one-step-ahead temperature of a given assembly. The incident is declared if the difference between the predicted process and the actual one exceeds a threshold. In these simulated conditions, the method is efficient to detect small gradients as expected in reality. - Highlights: • We study the total instantaneous blockage (TIB) of a sodium-cooled fast reactor. • The TIB symptom is simulated as an abrupt rise on temperature (0.1–1 °C/s). • The goal is to improve the early detection of the incident. • Two strategies laying on neural networks are proposed. • TIB is detected in 3 s for 1 °C/s and 18–21 s for 0.1 °C/s

  10. Development of an economic and efficient strategy to detect HBsAg: application of "gray-zones" in ELISA and combined use of several detection assays.

    Science.gov (United States)

    Peng, Jing; Cheng, Liming; Yin, Botao; Guan, Qing; Liu, Yanling; Wu, Shiji; Wang, Bin; Tang, Ning; Zhang, Biyu; Wang, Lian; Yang, Dongliang; Sun, Ziyong

    2011-11-20

    ELISA and CMIA are commonly used for detection of HBsAg. However, few investigations have been performed to evaluate their value in clinical practice, especially when jointly used. A reasonable and economic HBsAg testing algorithm is in great need. A total of 161,426 specimens in China were tested for 5 serum HBV markers with commonly used ELISA kits. 498 of these specimens were further tested for HBsAg by another ELISA kit, a CMIA kit and an HBsAg confirmatory assay. The sensitivities of the 2 ELISA kits were 76.21% and 88.42%, respectively. However, when using "gray-zones", the sensitivities were significantly improved to 97.43% and 96.43%. Furthermore, the combined use of the 2 ELISA kits and their "gray-zones" improved the sensitivity to 99.04%. Nevertheless, 2.91% of the samples with S/CO values below the lower "gray-zone" limits were reactive by the CMIA kit and then confirmed as HBsAg positive. However, 71.43% of the samples with HBsAg values within 0.05 and 0.10 IU/ml detected by the CMIA kit could not be confirmed. As a rational and economic strategy, combined use of "gray-zones" in ELISA and several different detection assays can significantly increase the efficiency of HBsAg detection. Copyright © 2011 Elsevier B.V. All rights reserved.

  11. OBSERVATIONAL SELECTION EFFECTS WITH GROUND-BASED GRAVITATIONAL WAVE DETECTORS

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Hsin-Yu; Holz, Daniel E. [University of Chicago, Chicago, Illinois 60637 (United States); Essick, Reed; Vitale, Salvatore; Katsavounidis, Erik [LIGO, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

    2017-01-20

    Ground-based interferometers are not perfect all-sky instruments, and it is important to account for their behavior when considering the distribution of detected events. In particular, the LIGO detectors are most sensitive to sources above North America and the Indian Ocean, and as the Earth rotates, the sensitive regions are swept across the sky. However, because the detectors do not acquire data uniformly over time, there is a net bias on detectable sources’ right ascensions. Both LIGO detectors preferentially collect data during their local night; it is more than twice as likely to be local midnight than noon when both detectors are operating. We discuss these selection effects and how they impact LIGO’s observations and electromagnetic (EM) follow-up. Beyond galactic foregrounds associated with seasonal variations, we find that equatorial observatories can access over 80% of the localization probability, while mid-latitudes will access closer to 70%. Facilities located near the two LIGO sites can observe sources closer to their zenith than their analogs in the south, but the average observation will still be no closer than 44° from zenith. We also find that observatories in Africa or the South Atlantic will wait systematically longer before they can begin observing compared to the rest of the world; though, there is a preference for longitudes near the LIGOs. These effects, along with knowledge of the LIGO antenna pattern, can inform EM follow-up activities and optimization, including the possibility of directing observations even before gravitational-wave events occur.

  12. Improved Data-based Fault Detection Strategy and Application to Distillation Columns

    KAUST Repository

    Madakyaru, Muddu

    2017-01-31

    Chemical and petrochemical processes require continuous monitoring to detect abnormal events and to sustain normal operations. Furthermore, process monitoring enhances productivity, efficiency, and safety in process industries. Here, we propose an innovative statistical approach that exploits the advantages of multiscale partial least squares (MSPLS) models and generalized likelihood ratio (GLR) tests for fault detection in processes. Specifically, we combine an MSPLS algorithm with wavelet analysis to create our modeling framework. Then, we use GLR hypothesis testing based on the uncorrelated residuals obtained from the MSPLS model to improve fault detection. We use simulated distillation column data to evaluate the MSPLS-based GLR chart. Results show that our MSPLS-based GLR method is more powerful than the PLS-based Q and GLR method and MSPLS-based Q method, especially in early detection of small faults with abrupt or incipient behavior.

  13. Development of cost effective fenceline monitoring methods to support advanced leak detection and repair strategies

    Science.gov (United States)

    Improved mitigation of fugitive emissions of hazardous air pollutants (HAPs), volatile organic compounds (VOCs), and greenhouse gas (GHG) emissions is an important emerging topic in many industrial sectors. Efficacious leak detection and repair (LDAR) programs of the future yiel...

  14. Multidisciplinary Strategies in the Prevention and Early Detection of Ovarian Cancer

    National Research Council Canada - National Science Library

    Mok, Samuel

    2003-01-01

    .... They have shown that Protease M over-expressed in a majority of stage I tumors and can be secreted by ovarian cancer cells in Project 2, suggesting that it is a potential marker for early detection of the disease...

  15. Multidisciplinary Strategies in the Prevention and Early Detection of Ovarian Cancer

    National Research Council Canada - National Science Library

    Mok, Samuel

    2001-01-01

    This program project consists of 4 research projects. Project I studies genetic changes in microdissected microscopic Stage I ovarian cancer cells, and identify markers for early detection of the disease...

  16. The Strategy of Discrimination between Flavors for Detection of Cosmogenic Neutrinos

    OpenAIRE

    Lai, Kwang-Chang; Chen, Chih-Ching; Chen, Pisin

    2013-01-01

    We propose a new method to identify flavors of ultra high energy cosmic neutrinos. Energy loss of leptons in matter provides important informations for the detection of neutrinos originated from high energy astrophysical sources. 50 years ago, Askaryan proposed to detect Cherenkov signals by radio wave from the negative charge excess of particle showers. The theory of Cherenkov pulses with Fraunhofer approximation was widely studied in the past two decades. However, at high energies or for hi...

  17. Intercomparison of ground-based ozone and NO2 measurements during the MANTRA 2004 campaign

    Directory of Open Access Journals (Sweden)

    K. Strong

    2007-11-01

    Full Text Available The MANTRA (Middle Atmosphere Nitrogen TRend Assessment 2004 campaign took place in Vanscoy, Saskatchewan, Canada (52° N, 107° W from 3 August to 15 September, 2004. In support of the main balloon launch, a suite of five zenith-sky and direct-Sun-viewing UV-visible ground-based spectrometers was deployed, primarily measuring ozone and NO2 total columns. Three Fourier transform spectrometers (FTSs that were part of the balloon payload also performed ground-based measurements of several species, including ozone. Ground-based measurements of ozone and NO2 differential slant column densities from the zenith-viewing UV-visible instruments are presented herein. They are found to partially agree within NDACC (Network for the Detection of Atmospheric Composition Change standards for instruments certified for process studies and satellite validation. Vertical column densities of ozone from the zenith-sky UV-visible instruments, the FTSs, a Brewer spectrophotometer, and ozonesondes are compared, and found to agree within the combined error estimates of the instruments (15%. NO2 vertical column densities from two of the UV-visible instruments are compared, and are also found to agree within combined error (15%.

  18. Detective Questions: A Strategy for Improving Inference-Making in Children With Mild Disabilities

    Science.gov (United States)

    Jiménez-Fernández, Gracia

    2015-01-01

    One of the most frequent problems in reading comprehension is the difficulty in making inferences from the text, especially for students with mild disabilities (i.e., children with learning disabilities or with high-functioning autism). It is essential, therefore, that educators include the teaching of reading strategies to improve their students'…

  19. The SPARC water vapor assessment II: intercomparison of satellite and ground-based microwave measurements

    Science.gov (United States)

    Nedoluha, Gerald E.; Kiefer, Michael; Lossow, Stefan; Gomez, R. Michael; Kämpfer, Niklaus; Lainer, Martin; Forkman, Peter; Christensen, Ole Martin; Oh, Jung Jin; Hartogh, Paul; Anderson, John; Bramstedt, Klaus; Dinelli, Bianca M.; Garcia-Comas, Maya; Hervig, Mark; Murtagh, Donal; Raspollini, Piera; Read, William G.; Rosenlof, Karen; Stiller, Gabriele P.; Walker, Kaley A.

    2017-12-01

    As part of the second SPARC (Stratosphere-troposphere Processes And their Role in Climate) water vapor assessment (WAVAS-II), we present measurements taken from or coincident with seven sites from which ground-based microwave instruments measure water vapor in the middle atmosphere. Six of the ground-based instruments are part of the Network for the Detection of Atmospheric Composition Change (NDACC) and provide datasets that can be used for drift and trend assessment. We compare measurements from these ground-based instruments with satellite datasets that have provided retrievals of water vapor in the lower mesosphere over extended periods since 1996. We first compare biases between the satellite and ground-based instruments from the upper stratosphere to the upper mesosphere. We then show a number of time series comparisons at 0.46 hPa, a level that is sensitive to changes in H2O and CH4 entering the stratosphere but, because almost all CH4 has been oxidized, is relatively insensitive to dynamical variations. Interannual variations and drifts are investigated with respect to both the Aura Microwave Limb Sounder (MLS; from 2004 onwards) and each instrument's climatological mean. We find that the variation in the interannual difference in the mean H2O measured by any two instruments is typically ˜ 1%. Most of the datasets start in or after 2004 and show annual increases in H2O of 0-1 % yr-1. In particular, MLS shows a trend of between 0.5 % yr-1 and 0.7 % yr-1 at the comparison sites. However, the two longest measurement datasets used here, with measurements back to 1996, show much smaller trends of +0.1 % yr-1 (at Mauna Loa, Hawaii) and -0.1 % yr-1 (at Lauder, New Zealand).

  20. The SPARC water vapor assessment II: intercomparison of satellite and ground-based microwave measurements

    Directory of Open Access Journals (Sweden)

    G. E. Nedoluha

    2017-12-01

    Full Text Available As part of the second SPARC (Stratosphere–troposphere Processes And their Role in Climate water vapor assessment (WAVAS-II, we present measurements taken from or coincident with seven sites from which ground-based microwave instruments measure water vapor in the middle atmosphere. Six of the ground-based instruments are part of the Network for the Detection of Atmospheric Composition Change (NDACC and provide datasets that can be used for drift and trend assessment. We compare measurements from these ground-based instruments with satellite datasets that have provided retrievals of water vapor in the lower mesosphere over extended periods since 1996. We first compare biases between the satellite and ground-based instruments from the upper stratosphere to the upper mesosphere. We then show a number of time series comparisons at 0.46 hPa, a level that is sensitive to changes in H2O and CH4 entering the stratosphere but, because almost all CH4 has been oxidized, is relatively insensitive to dynamical variations. Interannual variations and drifts are investigated with respect to both the Aura Microwave Limb Sounder (MLS; from 2004 onwards and each instrument's climatological mean. We find that the variation in the interannual difference in the mean H2O measured by any two instruments is typically  ∼  1%. Most of the datasets start in or after 2004 and show annual increases in H2O of 0–1 % yr−1. In particular, MLS shows a trend of between 0.5 % yr−1 and 0.7 % yr−1 at the comparison sites. However, the two longest measurement datasets used here, with measurements back to 1996, show much smaller trends of +0.1 % yr−1 (at Mauna Loa, Hawaii and −0.1 % yr−1 (at Lauder, New Zealand.

  1. Label-free fluorescence strategy for sensitive detection of adenosine triphosphate using a loop DNA probe with low background noise.

    Science.gov (United States)

    Lin, Chunshui; Cai, Zhixiong; Wang, Yiru; Zhu, Zhi; Yang, Chaoyong James; Chen, Xi

    2014-07-15

    A simple, rapid, label-free, and ultrasensitive fluorescence strategy for adenosine triphosphate (ATP) detection was developed using a loop DNA probe with low background noise. In this strategy, a loop DNA probe, which is the substrate for both ligation and digestion enzyme reaction, was designed. SYBR green I (SG I), a double-stranded specific dye, was applied for the readout fluorescence signal. Exonuclease I (Exo I) and exonuclease III (Exo III), sequence-independent nucleases, were selected to digest the loop DNA probe in order to minimize the background fluorescence signal. As a result, in the absence of ATP, the loop DNA was completely digested by Exo I and Exo III, leading to low background fluorescence owing to the weak electrostatic interaction between SG I and mononucleotides. On the other hand, ATP induced the ligation of the nicking site, and the sealed loop DNA resisted the digestion of Exo I and ExoIII, resulting in a remarkable increase of fluorescence response. Upon background noise reduction, the sensitivity of the ATP determination was improved significantly, and the detection limitation was found to be 1.2 pM, which is much lower than that in almost all the previously reported methods. This strategy has promise for wide application in the determination of ATP.

  2. The strategies of DNA immobilization and hybridization detection mechanism in the construction of electrochemical DNA sensor: A review

    Directory of Open Access Journals (Sweden)

    Jahwarhar Izuan Abdul Rashid

    2017-11-01

    Full Text Available In recent years, electrochemical deoxyribonucleic acid (DNA sensor has recently emerged as promising alternative clinical diagnostic devices especially for infectious disease by exploiting DNA recognition events and converting them into an electrochemical signal. This is because the existing DNA diagnostic method possesses certain drawbacks such as time-consuming, expensive, laborious, low selectivity and sensitivity. DNA immobilization strategies and mechanism of electrochemical detection are two the most important aspects that should be considered before developing highly selective and sensitive electrochemical DNA sensor. Here, we focus on some recent strategies for DNA probes immobilization on the surface of electrochemical transducer such as adsorption, covalent bonding and Avidin/Streptavidin-Biotin interaction on the electrode surface for specific interaction with its complementary DNA target. A numerous approach for DNA hybridization detection based electrochemical technique that frequently used including direct DNA electrochemical detection and label based electrochemical (redox-active indicator, enzyme label and nanoparticles were also discussed in aiming to provide general guide for the design of electrochemical DNA sensor. We also discussed the challenges and suggestions to improve the application of electrochemical DNA sensor at point-care setting. Keywords: Electrochemical DNA sensor, DNA immobilization, DNA hybridization, Electrochemical mechanism

  3. Analytical strategy for the detection of antibiotic residues in sheep and goat’s milk

    Directory of Open Access Journals (Sweden)

    M. Carmen Beltrán

    2015-03-01

    Full Text Available The use of antibiotics to treat mastitis and other infectious diseases in dairy sheep and goats is a widespread practice nowadays that can, when not properly applied, result in the contamination of the milk supply. Spanish legislation establishes the control of the presence of antibiotic residues in sheep and goat’s milk using screening methods that detect, at least, beta-lactam drugs. Microbial inhibitor tests using Geobacillus stearothermophilus var. calidolactis and specific receptor-binding assays are most widely employed for this purpose. The detection rates of screening tests routinely used in Spain have been calculated considering the frequency of use of veterinary drugs commonly applied in ovine and caprine livestock to treat and prevent mastitis as well as the test sensitivity toward these substances at safety levels. In general, the use of a single test allows detecting 62.8-82.4% of the antibiotics employed. For sheep milk, the total detection range achieved with microbial tests was significantly higher than that reached with rapid receptor tests. However, no significant differences between the two types of methods were found when goat’s milk was analysed. In both types of milk, the simultaneous use of two screening tests with a different analytical basis increases the total detection range significantly, reaching values ≥ 90% in some cases (81.5-90.1% for sheep and 84.7-92.6% for goats. However, the periodical use of screening tests able to detect quinolones, macrolides or aminoglycosides would be recommended to carry out more efficient screening and ensure the safety of milk and dairy products from sheep and goats.

  4. Analytical strategy for the detection of antibiotic residues in sheep and goat’s milk

    Energy Technology Data Exchange (ETDEWEB)

    Beltrán, M.C.; Althaus, R.L.; Molina, A.; Berruga, M.I.; Molina, M.P.

    2015-07-01

    The use of antibiotics to treat mastitis and other infectious diseases in dairy sheep and goats is a widespread practice nowadays that can, when not properly applied, result in the contamination of the milk supply. Spanish legislation establishes the control of the presence of antibiotic residues in sheep and goat’s milk using screening methods that detect, at least, beta-lactam drugs. Microbial inhibitor tests using Geobacillus stearothermophilus var. calidolactis and specific receptor-binding assays are most widely employed for this purpose. The detection rates of screening tests routinely used in Spain have been calculated considering the frequency of use of veterinary drugs commonly applied in ovine and caprine livestock to treat and prevent mastitis as well as the test sensitivity toward these substances at safety levels. In general, the use of a single test allows detecting 62.8-82.4% of the antibiotics employed. For sheep milk, the total detection range achieved with microbial tests was significantly higher than that reached with rapid receptor tests. However, no significant differences between the two types of methods were found when goat's milk was analysed. In both types of milk, the simultaneous use of two screening tests with a different analytical basis increases the total detection range significantly, reaching values ≥ 90% in some cases (81.5-90.1% for sheep and 84.7-92.6% for goats). However, the periodical use of screening tests able to detect quinolones, macrolides or aminoglycosides would be recommended to carry out more efficient screening and ensure the safety of milk and dairy products from sheep and goats. (Author)

  5. Strategies for Early Outbreak Detection of Malaria in the Amhara Region of Ethiopia

    Science.gov (United States)

    Nekorchuk, D.; Gebrehiwot, T.; Mihretie, A.; Awoke, W.; Wimberly, M. C.

    2017-12-01

    Traditional epidemiological approaches to early detection of disease outbreaks are based on relatively straightforward thresholds (e.g. 75th percentile, standard deviations) estimated from historical case data. For diseases with strong seasonality, these can be modified to create separate thresholds for each seasonal time step. However, for disease processes that are non-stationary, more sophisticated techniques are needed to more accurately estimate outbreak threshold values. Early detection for geohealth-related diseases that also have environmental drivers, such as vector-borne diseases, may also benefit from the integration of time-lagged environmental data and disease ecology models into the threshold calculations. The Epidemic Prognosis Incorporating Disease and Environmental Monitoring for Integrated Assessment (EPIDEMIA) project has been integrating malaria case surveillance with remotely-sensed environmental data for early detection, warning, and forecasting of malaria epidemics in the Amhara region of Ethiopia, and has five years of weekly time series data from 47 woredas (districts). Efforts to reduce the burden of malaria in Ethiopia has been met with some notable success in the past two decades with major reduction in cases and deaths. However, malaria remains a significant public health threat as 60% of the population live in malarious areas, and due to the seasonal and unstable transmission patterns with cyclic outbreaks, protective immunity is generally low which could cause high morbidity and mortality during the epidemics. This study compared several approaches for defining outbreak thresholds and for identifying a potential outbreak based on deviations from these thresholds. We found that model-based approaches that accounted for climate-driven seasonality in malaria transmission were most effective, and that incorporating a trend component improved outbreak detection in areas with active malaria elimination efforts. An advantage of these early

  6. Improved detection of multiple environmental antibiotics through an optimized sample extraction strategy in liquid chromatography-mass spectrometry analysis.

    Science.gov (United States)

    Yi, Xinzhu; Bayen, Stéphane; Kelly, Barry C; Li, Xu; Zhou, Zhi

    2015-12-01

    A solid-phase extraction/liquid chromatography/electrospray ionization/multi-stage mass spectrometry (SPE-LC-ESI-MS/MS) method was optimized in this study for sensitive and simultaneous detection of multiple antibiotics in urban surface waters and soils. Among the seven classes of tested antibiotics, extraction efficiencies of macrolides, lincosamide, chloramphenicol, and polyether antibiotics were significantly improved under optimized sample extraction pH. Instead of only using acidic extraction in many existing studies, the results indicated that antibiotics with low pK a values (antibiotics with high pK a values (>7) were extracted more efficiently under neutral conditions. The effects of pH were more obvious on polar compounds than those on non-polar compounds. Optimization of extraction pH resulted in significantly improved sample recovery and better detection limits. Compared with reported values in the literature, the average reduction of minimal detection limits obtained in this study was 87.6% in surface waters (0.06-2.28 ng/L) and 67.1% in soils (0.01-18.16 ng/g dry wt). This method was subsequently applied to detect antibiotics in environmental samples in a heavily populated urban city, and macrolides, sulfonamides, and lincomycin were frequently detected. Antibiotics with highest detected concentrations were sulfamethazine (82.5 ng/L) in surface waters and erythromycin (6.6 ng/g dry wt) in soils. The optimized sample extraction strategy can be used to improve the detection of a variety of antibiotics in environmental surface waters and soils.

  7. Signal amplification strategies for DNA and protein detection based on polymeric nanocomposites and polymerization: A review

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Shaohong; Yuan, Liang; Hua, Xin; Xu, Lingling; Liu, Songqin, E-mail: liusq@seu.edu.cn

    2015-06-02

    Highlights: • We review the innovative advances in polymer-based signal amplification. • Conceptual connectivity between different amplified methodologies is illustrated. • Examples explain the mechanisms of polymers/polymerizations-based amplification. • Several elegant applications are summarized that illustrate underlying concept. - Abstract: Demand is increasing for ultrasensitive bioassays for disease diagnosis, environmental monitoring and other research areas. This requires novel signal amplification strategies to maximize the signal output. In this review, we focus on a series of significant signal amplification strategies based on polymeric nanocomposites and polymerization. Some common polymers are used as carriers to increase the local concentration of signal probes and/or biomolecules on their surfaces or in their interiors. Some polymers with special fluorescence and optical properties can efficiently transfer the excitation energy from a single site to the whole polymer backbone. This results in superior fluorescence signal amplification due to the resulting collective effort (integration of signal). Recent polymerization-based signal amplification strategies that employ atom transfer radical polymerization (ATRP) and photo-initiated polymerization are also summarized. Several distinctive applications of polymers in ultrasensitive bioanalysis are highlighted.

  8. Strategy for increasing detection rates of drug and alcohol abuse in paediatric emergency departments.

    Science.gov (United States)

    Kozer, E; Bar-Hamburger, R; Rosenfeld, N; Dalal, I; Landu, O; Fainmesser, P; Ben-Yehuda, Y; Berkovitch, M

    2009-10-01

    To determine whether implementation of criteria for performing a toxicology screen and increasing staff awareness improve detection of substance abuse among adolescents presenting to the emergency department. Patients 12 to 18 years of age presenting to one of three emergency departments in Israel were included in a prospective cohort study. In the 'study' hospital, a set of criteria for urine toxicology screen and measurements of ethanol serum level were implemented. No specific interventions were implemented in the two other hospitals. The main outcome measure was the rate of substance abuse detection. The number of adolescents seen in the participating centres was 3200 at the study hospital, and 3493 and 2792 at the two other hospitals. High blood ethanol concentrations were found in 49 patients at the study hospital compared with 30 and 19 patients at the two other hospitals (p < 0.001). Illicit drugs were detected in 13, 4 and 1 patients, respectively (p = 0.002). Introducing structured guidelines for ordering toxicological screening increases the detection of alcohol and drug of abuse among adolescents presenting to paediatric emergency departments.

  9. A net fishing enrichment strategy for colorimetric detection of E. coli O157:H7

    Science.gov (United States)

    The strict regulatory requirements for pathogen monitoring in food systems to ensure safety demands that the detection method can recognize small numbers of pathogens. Although significant efforts on the development of biosensors have been reported with marked improvement in sensitivity, appropriate...

  10. Improved nonlinear fault detection strategy based on the Hellinger distance metric: Plug flow reactor monitoring

    KAUST Repository

    Harrou, Fouzi

    2017-03-18

    Fault detection has a vital role in the process industry to enhance productivity, efficiency, and safety, and to avoid expensive maintenance. This paper proposes an innovative multivariate fault detection method that can be used for monitoring nonlinear processes. The proposed method merges advantages of nonlinear projection to latent structures (NLPLS) modeling and those of Hellinger distance (HD) metric to identify abnormal changes in highly correlated multivariate data. Specifically, the HD is used to quantify the dissimilarity between current NLPLS-based residual and reference probability distributions obtained using fault-free data. Furthermore, to enhance further the robustness of these methods to measurement noise, and reduce the false alarms due to modeling errors, wavelet-based multiscale filtering of residuals is used before the application of the HD-based monitoring scheme. The performances of the developed NLPLS-HD fault detection technique is illustrated using simulated plug flow reactor data. The results show that the proposed method provides favorable performance for detection of faults compared to the conventional NLPLS method.

  11. A review of analytical strategies for the detection of endogenous' steroid abuse in food production

    NARCIS (Netherlands)

    Scarth, J.P.; Kay, J.; Teale, P.; Akre, C.; Bizec, le B.; Brabander, de H.F.; Vanhaecke, L.; Ginkel, van L.A.; Points, J.

    2012-01-01

    Detection of the abuse of synthetic steroids in food production is nowadays relatively straightforward using modern techniques such as gas or liquid chromatography coupled to mass spectrometry (GC-MS/MS or LC-MS/MS, respectively). However, proving the abuse of endogenous (or naturally occurring)

  12. Detection of (anti)symmetry and (anti)repetition: Perceptual mechanisms versus cognitive strategies

    NARCIS (Netherlands)

    Helm, P.A. van der; Treder, M.S.

    2009-01-01

    Symmetry and repetition are recognized as cues in perceptual organization, but there is disagreement on whether they are detected automatically. This disagreement is resolved by noting that some studies mixed up shape regularities and shape antiregularities (i.e., symmetries and repetitions with

  13. Efficient strategy for detecting gene × gene joint action and its application in schizophrenia

    NARCIS (Netherlands)

    Won, Sungho; Kwon, Min-Seok; Mattheisen, Manuel; Park, Suyeon; Park, Changsoon; Kihara, Daisuke; Cichon, Sven; Ophoff, Roel; Nöthen, Markus M.; Rietschel, Marcella; Baur, Max; Uitterlinden, Andre G.; Hofmann, A.; Lange, Christoph; Kahn, René S.; Linszen, Don H.; van Os, Jim; Wiersma, Durk; Bruggeman, Richard; Cahn, Wiepke; de Haan, Lieuwe; Krabbendam, Lydia; Myin-Germeys, Inez

    2014-01-01

    We propose a new approach to detect gene × gene joint action in genome-wide association studies (GWASs) for case-control designs. This approach offers an exhaustive search for all two-way joint action (including, as a special case, single gene action) that is computationally feasible at the

  14. Strategy for improved NH2 detection in combustion environments using an Alexandrite laser

    Science.gov (United States)

    Brackmann, Christian; Zhou, Bo; Samuelsson, Per; Alekseev, Vladimir A.; Konnov, Alexander A.; Li, Zhongshan; Aldén, Marcus

    2017-09-01

    A new scheme for NH2 detection by means of laser-induced fluorescence (LIF) with excitation around wavelength 385 nm, accessible using the second harmonic of a solid-state Alexandrite laser, is presented. Detection of NH2 was confirmed by identification of corresponding lines in fluorescence excitation spectra measured in premixed NH3-air flames and on NH2 radicals generated through NH3 photolysis in a nonreactive flow at ambient conditions. Moreover, spectral simulations allow for tentative NH2 line identification. Dispersed fluorescence emission spectra measured in flames and photolysis experiments showed lines attributed to vibrational bands of the NH2 A2A1 ← X2B1 transition but also a continuous structure, which in flame was observed to be dependent on nitrogen added to the fuel, apparently also generated by NH2. A general conclusion was that fluorescence interferences need to be carefully considered for NH2 diagnostics in this spectral region. Excitation for laser irradiances up to 0.2 GW/cm2 did not result in NH2 fluorescence saturation and allowed for efficient utilization of the available laser power without indication of laser-induced photochemistry. Compared with a previously employed excitation/detection scheme for NH2 at around 630 nm, excitation at 385.7 nm showed a factor of 15 higher NH2 signal. The improved signal allowed for single-shot NH2 LIF imaging on centimeter scale in flame with signal-to-noise ratio of 3 for concentrations around 1000 ppm, suggesting a detection limit around 700 ppm. Thus, the presented approach for NH2 detection provides enhanced possibilities for characterization of fuel-nitrogen combustion chemistry.

  15. Soil remediation: New strategy by the combine of F.I.S. H. and Geo-Radar Tele detection

    International Nuclear Information System (INIS)

    Garbi, C.; Mengs, G.; Gonzalez Motalvo, D.; Martin, M.

    2009-01-01

    One of the most important targets in bioremediation to treat contaminated soils is the developing of new technologies. In this project we have developed a new strategy to eliminate in situ pollutants from hydrocarbons contaminated soils, supported with two specific techniques: FISH and Geo-Radar tele detection. With these techniques we try to delimit the pollutants distribution is oil, and to develop DNA and PNA biosensors with high specificity to evaluate the natural attenuation soil capacity using fluorescence in situ hybridization (FISH). (Author)

  16. Rationally modified estrogen receptor protein as a bio-recognition element for the detection of EDC pollutants: strategies and opportunities.

    Science.gov (United States)

    Pedotti, Mattia; Ferrero, Valentina Elisabetta Viviana; Lettieri, Teresa; Colpo, Pascal; Follonier, Stephane; Calzolai, Luigi; Varani, Luca

    2015-02-27

    The estrogen receptor protein (ER) can bind a vast number of organic pollutants widely spread in the environment and collectively known as Endocrine Disrupting Chemicals, EDCs. Its broad selectivity makes it an ideal bio-recognition element for the detection of EDCs. Here we describe the strategy and rationale for the design of ER based biosensors and assays that generate a signal in the presence of EDCs. The opportunity to use either natural or rationally modified ER molecules is discussed. The latter approach was successfully applied in the EU-FP7 project RADAR, with the aim to develop a novel biosensor for the detection of organic pollutants both in the environment and in commercial water products.

  17. Rationally Modified Estrogen Receptor Protein as a Bio-Recognition Element for the Detection of EDC Pollutants: Strategies and Opportunities

    Directory of Open Access Journals (Sweden)

    Mattia Pedotti

    2015-02-01

    Full Text Available The estrogen receptor protein (ER can bind a vast number of organic pollutants widely spread in the environment and collectively known as Endocrine Disrupting Chemicals, EDCs. Its broad selectivity makes it an ideal bio-recognition element for the detection of EDCs. Here we describe the strategy and rationale for the design of ER based biosensors and assays that generate a signal in the presence of EDCs. The opportunity to use either natural or rationally modified ER molecules is discussed. The latter approach was successfully applied in the EU-FP7 project RADAR, with the aim to develop a novel biosensor for the detection of organic pollutants both in the environment and in commercial water products.

  18. Development of a variable structure-based fault detection and diagnosis strategy applied to an electromechanical system

    Science.gov (United States)

    Gadsden, S. Andrew; Kirubarajan, T.

    2017-05-01

    Signal processing techniques are prevalent in a wide range of fields: control, target tracking, telecommunications, robotics, fault detection and diagnosis, and even stock market analysis, to name a few. Although first introduced in the 1950s, the most popular method used for signal processing and state estimation remains the Kalman filter (KF). The KF offers an optimal solution to the estimation problem under strict assumptions. Since this time, a number of other estimation strategies and filters were introduced to overcome robustness issues, such as the smooth variable structure filter (SVSF). In this paper, properties of the SVSF are explored in an effort to detect and diagnosis faults in an electromechanical system. The results are compared with the KF method, and future work is discussed.

  19. Universal, colorimetric microRNA detection strategy based on target-catalyzed toehold-mediated strand displacement reaction

    Science.gov (United States)

    Park, Yeonkyung; Lee, Chang Yeol; Kang, Shinyoung; Kim, Hansol; Park, Ki Soo; Park, Hyun Gyu

    2018-02-01

    In this work, we developed a novel, label-free, and enzyme-free strategy for the colorimetric detection of microRNA (miRNA), which relies on a target-catalyzed toehold-mediated strand displacement (TMSD) reaction. The system employs a detection probe that specifically binds to the target miRNA and sequentially releases a catalyst strand (CS) intended to trigger the subsequent TMSD reaction. Thus, the presence of target miRNA releases the CS that mediates the formation of an active G-quadruplex DNAzyme which is initially caged and inactivated by a blocker strand. In addition, a fuel strand that is supplemented for the recycling of the CS promotes another TMSD reaction, consequently generating a large number of active G-quadruplex DNAzymes. As a result, a distinct colorimetric signal is produced by the ABTS oxidation promoted by the peroxidase mimicking activity of the released G-quadruplex DNAzymes. Based on this novel strategy, we successfully detected miR-141, a promising biomarker for human prostate cancer, with high selectivity. The diagnostic capability of this system was also demonstrated by reliably determining target miR-141 in human serum, showing its great potential towards real clinical applications. Importantly, the proposed approach is composed of separate target recognition and signal transduction modules. Thus, it could be extended to analyze different target miRNAs by simply redesigning the detection probe while keeping the same signal transduction module as a universal signal amplification unit, which was successfully demonstrated by analyzing another target miRNA, let-7d.

  20. Developing optimal search strategies for detecting clinically sound prognostic studies in MEDLINE: an analytic survey

    Directory of Open Access Journals (Sweden)

    Haynes R Brian

    2004-06-01

    Full Text Available Abstract Background Clinical end users of MEDLINE have a difficult time retrieving articles that are both scientifically sound and directly relevant to clinical practice. Search filters have been developed to assist end users in increasing the success of their searches. Many filters have been developed for the literature on therapy and reviews but little has been done in the area of prognosis. The objective of this study is to determine how well various methodologic textwords, Medical Subject Headings, and their Boolean combinations retrieve methodologically sound literature on the prognosis of health disorders in MEDLINE. Methods An analytic survey was conducted, comparing hand searches of journals with retrievals from MEDLINE for candidate search terms and combinations. Six research assistants read all issues of 161 journals for the publishing year 2000. All articles were rated using purpose and quality indicators and categorized into clinically relevant original studies, review articles, general papers, or case reports. The original and review articles were then categorized as 'pass' or 'fail' for methodologic rigor in the areas of prognosis and other clinical topics. Candidate search strategies were developed for prognosis and run in MEDLINE – the retrievals being compared with the hand search data. The sensitivity, specificity, precision, and accuracy of the search strategies were calculated. Results 12% of studies classified as prognosis met basic criteria for scientific merit for testing clinical applications. Combinations of terms reached peak sensitivities of 90%. Compared with the best single term, multiple terms increased sensitivity for sound studies by 25.2% (absolute increase, and increased specificity, but by a much smaller amount (1.1% when sensitivity was maximized. Combining terms to optimize both sensitivity and specificity achieved sensitivities and specificities of approximately 83% for each. Conclusion Empirically derived

  1. Developing Optimal Search Strategies for Detecting Clinically Sound Causation Studies in MEDLINE

    Science.gov (United States)

    Wilczynski, Nancy L.; Haynes, R. Brian

    2003-01-01

    Background Clinical end users of MEDLINE must be able to retrieve articles that are both scientifically sound and directly relevant to clinical practice. The use of methodologic search filters has been advocated to improve the accuracy of searching for such studies. These filters are available for the literature on therapy and diagnosis, but strategies for the literature on causation have been less well studied. Objective To determine the retrieval characteristics of methodologic terms in MEDLINE for identifying methodologically sound studies on causation. Design Comparison of methodologic search terms and phrases for the retrieval of citations in MEDLINE with a manual hand search of the literature (the gold standard) for 161 core health care journals. Methods 6 trained, experienced research assistants read all issues of 161 journals for the publishing year 2000. Each article was rated using purpose and quality indicators and categorized into clinically relevant original studies, review articles, general papers, or case reports. The original and review articles were then categorized as ‘pass’ or ‘fail’ for methodologic rigor in the areas of therapy/quality improvement, diagnosis, prognosis, causation, economics, clinical prediction, and review articles. Search strategies were developed for all categories including causation. Main outcome measures Sensitivity, specificity, precision, and accuracy of the search strategies. Results 12% of studies classified as causation met basic criteria for scientific merit for testing clinical applications. Combinations of terms reached peak sensitivities of 93%. Compared with the best single term, multiple terms increased sensitivity for sound studies by 15.5% (absolute increase), but with some loss of specificity when sensitivity was maximized. Combining terms to optimize sensitivity and specificity achieved sensitivities and specificities both above 80%. Conclusion The retrieval of causation studies cited in MEDLINE can

  2. Evaluation of Three Hydration Strategies in Detection Dogs Working in a Hot Environment

    Directory of Open Access Journals (Sweden)

    Cynthia M. Otto

    2017-10-01

    Full Text Available Physical activity in hot environments can increase the risk of heat stress or heat stroke in dogs. Heat tolerance is influenced by acclimatization to the environment, physical fitness, and hydration state. Three common strategies to promote hydration in working dogs are free access to water (W, oral electrolyte solutions (OESs, and administration of subcutaneous fluids (SQs. None of these methods have been compared for safety or efficacy in a working environment. In a cross-over design, seven vehicle-screening canines were randomly assigned to each of the three hydration strategies during working shifts at the Sarita, TX checkpoint. Physical, behavioral, and biochemical parameters were collected before, during, and after a work shift (mean 5.7 ± 0.8 h. Dogs were given 10 mL/kg oral W, 10 mL/kg chicken flavored OES, or 15 mL/kg of SQs initially followed by controlled access to W or OES. The dogs drank 15.61 ± 4.47 mL/kg/h of W and OES when in the OES group, compared to 7.04 ± 3.42 and 5.56 ± 4.40 mL of W, for the W and SQ groups, respectively. The median environmental temperature was 84.8°F (29.3°C. The median humidity was 70%. Based on mixed effects linear modeling, dogs in the OES and SQ groups had significantly higher total CO2, and lower packed cell volume and total plasma protein at the end of the day. Creatinine increased a small but significant amount in the SQ group and decreased in the OES group. Searching behaviors were independent of hydration strategy but highly related to the dog specific factors of sex, breed, and activity level. Under conditions of controlled activity in moderate heat and humidity, dogs accustomed to the work and the environment were more likely to increase fluid consumption and hydration when provided a flavored OES. Potential benefits of OES and SQ were indirect and no adverse effects were documented for any of the hydration strategies tested.

  3. Evaluation of Three Hydration Strategies in Detection Dogs Working in a Hot Environment

    Science.gov (United States)

    Otto, Cynthia M.; Hare, Elizabeth; Nord, Jess L.; Palermo, Shannon M.; Kelsey, Kathleen M.; Darling, Tracy A.; Schmidt, Kasey; Coleman, Destiny

    2017-01-01

    Physical activity in hot environments can increase the risk of heat stress or heat stroke in dogs. Heat tolerance is influenced by acclimatization to the environment, physical fitness, and hydration state. Three common strategies to promote hydration in working dogs are free access to water (W), oral electrolyte solutions (OESs), and administration of subcutaneous fluids (SQs). None of these methods have been compared for safety or efficacy in a working environment. In a cross-over design, seven vehicle-screening canines were randomly assigned to each of the three hydration strategies during working shifts at the Sarita, TX checkpoint. Physical, behavioral, and biochemical parameters were collected before, during, and after a work shift (mean 5.7 ± 0.8 h). Dogs were given 10 mL/kg oral W, 10 mL/kg chicken flavored OES, or 15 mL/kg of SQs initially followed by controlled access to W or OES. The dogs drank 15.61 ± 4.47 mL/kg/h of W and OES when in the OES group, compared to 7.04 ± 3.42 and 5.56 ± 4.40 mL of W, for the W and SQ groups, respectively. The median environmental temperature was 84.8°F (29.3°C). The median humidity was 70%. Based on mixed effects linear modeling, dogs in the OES and SQ groups had significantly higher total CO2, and lower packed cell volume and total plasma protein at the end of the day. Creatinine increased a small but significant amount in the SQ group and decreased in the OES group. Searching behaviors were independent of hydration strategy but highly related to the dog specific factors of sex, breed, and activity level. Under conditions of controlled activity in moderate heat and humidity, dogs accustomed to the work and the environment were more likely to increase fluid consumption and hydration when provided a flavored OES. Potential benefits of OES and SQ were indirect and no adverse effects were documented for any of the hydration strategies tested. PMID:29124059

  4. Influence of antibody immobilization strategies on the analytical performance of a magneto-elastic immunosensor for Staphylococcus aureus detection.

    Science.gov (United States)

    Menti, C; Beltrami, M; Pozza, M D; Martins, S T; Henriques, J A P; Santos, A D; Missell, F P; Roesch-Ely, M

    2017-07-01

    Magneto-elastic (ME) sensors have a great advantage in microbiology due to their ability to be queried wirelessly. Staphylococcus aureus is one of the most common bacteria widespread in the environment and a major human pathogen related to numerous illnesses. Immunosensors are affinity-based assays where the analyte is highly selective. The immobilization of antibodies (Ab) is an important step in the development of such devices. This study compared the effects of two antibody immobilization strategies on the analytical performance of a magneto-elastic immunosensor: (1) random antibody covalent immobilization (CysAb) and (2) specific-oriented antibody covalent immobilization (PrGAb). Immunosensors were exposed to solutions containing S. aureus at different concentrations (10 4 to 10 8 CFU/ml) and sensor resonant frequencies were measured. In order to confirm that the frequency shifts were mainly caused by the binding of S. aureus to the sensor's surface, scanning electron microscope (SEM) and indirect immunofluorescence (IIF) images were taken after bacteria exposure at 10 8 CFU/ml. Sensor surfaces were further monitored by non-contact topographic atomic force microscopy (AFM) images. In the covalent-oriented strategy, PrG was first bound covalently to the surface, which in turn, then binds the anti-S. aureus antibody in an oriented manner. Topographic AFM images showed different surface patterns between the two antibody immobilization strategies. Specific-oriented antibody covalent immobilization (PrGAb) strategy gave the highest anti-S. aureus antibody immobilization density. Therefore, the covalent-oriented strategy presented the best performance for S. aureus capture, detecting 10 4 CFU/ml. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Evaluating Monitoring Strategies to Detect Precipitation-Induced Microbial Contamination Events in Karstic Springs Used for Drinking Water

    Directory of Open Access Journals (Sweden)

    Michael D. Besmer

    2017-11-01

    Full Text Available Monitoring of microbial drinking water quality is a key component for ensuring safety and understanding risk, but conventional monitoring strategies are typically based on low sampling frequencies (e.g., quarterly or monthly. This is of concern because many drinking water sources, such as karstic springs are often subject to changes in bacterial concentrations on much shorter time scales (e.g., hours to days, for example after precipitation events. Microbial contamination events are crucial from a risk assessment perspective and should therefore be targeted by monitoring strategies to establish both the frequency of their occurrence and the magnitude of bacterial peak concentrations. In this study we used monitoring data from two specific karstic springs. We assessed the performance of conventional monitoring based on historical records and tested a number of alternative strategies based on a high-resolution data set of bacterial concentrations in spring water collected with online flow cytometry (FCM. We quantified the effect of increasing sampling frequency and found that for the specific case studied, at least bi-weekly sampling would be needed to detect precipitation events with a probability of >90%. We then proposed an optimized monitoring strategy with three targeted samples per event, triggered by precipitation measurements. This approach is more effective and efficient than simply increasing overall sampling frequency. It would enable the water utility to (1 analyze any relevant event and (2 limit median underestimation of peak concentrations to approximately 10%. We conclude with a generalized perspective on sampling optimization and argue that the assessment of short-term dynamics causing microbial peak loads initially requires increased sampling/analysis efforts, but can be optimized subsequently to account for limited resources. This offers water utilities and public health authorities systematic ways to evaluate and optimize their

  6. OPTIMAL STRATEGIES FOR CONTINUOUS GRAVITATIONAL WAVE DETECTION IN PULSAR TIMING ARRAYS

    International Nuclear Information System (INIS)

    Ellis, J. A.; Siemens, X.; Creighton, J. D. E.

    2012-01-01

    Supermassive black hole binaries (SMBHBs) are expected to emit a continuous gravitational wave signal in the pulsar timing array (PTA) frequency band (10 –9 to 10 –7 Hz). The development of data analysis techniques aimed at efficient detection and characterization of these signals is critical to the gravitational wave detection effort. In this paper, we leverage methods developed for LIGO continuous wave gravitational searches and explore the use of the F-statistic for such searches in pulsar timing data. Babak and Sesana have used this approach in the context of PTAs to show that one can resolve multiple SMBHB sources in the sky. Our work improves on several aspects of prior continuous wave search methods developed for PTA data analysis. The algorithm is implemented fully in the time domain, which naturally deals with the irregular sampling typical of PTA data and avoids spectral leakage problems associated with frequency domain methods. We take into account the fitting of the timing model and have generalized our approach to deal with both correlated and uncorrelated colored noise sources. We also develop an incoherent detection statistic that maximizes over all pulsar-dependent contributions to the likelihood. To test the effectiveness and sensitivity of our detection statistics, we perform a number of Monte Carlo simulations. We produce sensitivity curves for PTAs of various configurations and outline an implementation of a fully functional data analysis pipeline. Finally, we present a derivation of the likelihood maximized over the gravitational wave phases at the pulsar locations, which results in a vast reduction of the search parameter space.

  7. A novel strategy for human papillomavirus detection and genotyping with SybrGreen and molecular beacon polymerase chain reaction.

    Science.gov (United States)

    Szuhai, K; Sandhaus, E; Kolkman-Uljee, S M; Lemaître, M; Truffert, J C; Dirks, R W; Tanke, H J; Fleuren, G J; Schuuring, E; Raap, A K

    2001-11-01

    Human papillomaviruses (HPVs) play an important role in the pathogenesis of cervical cancer. For identification of the large number of different HPV types found in (pre)malignant lesions, a robust methodology is needed that combines general HPV detection with HPV genotyping. We have developed for formaldehyde-fixed samples a strategy that, in a homogeneous, real-time fluorescence polymerase chain reaction (PCR)-based assay, accomplishes general HPV detection by SybrGreen reporting of HPV-DNA amplicons, and genotyping of seven prevalent HPV types (HPV-6, -11, -16, -18, -31, -33, -45) by real-time molecular beacon PCR. The false-positive rate of the HPV SybrGreen-PCR was 4%, making it well suited as a prescreening, general HPV detection technology. The type specificity of the seven selected HPV molecular beacons was 100% and double infections were readily identified. The multiplexing capacity of the HPV molecular beacon PCR was analyzed and up to three differently labeled molecular beacons could be used in one PCR reaction without observing cross talk. The inherent quantitation capacities of real-time fluorescence PCR allowed the determination of average HPV copy number per cell. We conclude that the HPV SybrGreen-PCR in combination with the HPV molecular beacon PCR provides a robust, sensitive, and quantitative general HPV detection and genotyping methodology.

  8. Strategies for detection of transfusion-transmitted viruses eluding identification by conventional serologic tests. I

    International Nuclear Information System (INIS)

    Neurath, A.R.; Strick, N.

    1983-01-01

    The unavailability of serological tests for detection of several not yet characterized infectious agents transmitted by blood transfusion or by blood products prompted the development of alternative tests based on utilization of labeled nucleic acid probes specific for genomes of each of these agents. The prerequisite for the preparation of such probes is the demonstration in human plasma of nucleic acid sequences distinct from those present in host DNA or in genes of already characterized viruses occurring in plasma of infected individuals. To accomplish this, ultrasensitive tests for nucleic acids not dependent on their base sequence are needed. The authors describe a radioimmunoassay (RIA) for picogram quantities of DNA. Plasma (serum) specimens are treated with proteinase K in the presence of sodium dodecyl sulfate and extracted with phenol. Nucleic acids are precipitated with ethanol in the presence of dextran (mol.wt. approx. 5X10 5 ) as carrier. Subsequently, DNA from the redissolved samples is adsorbed onto polylysine-coated wells of microtiter plates and detected by a double-antibody RIA using anti-DNA autoantibodies from NZB/NZW mice and 125 I-labelled antibodies to mouse immunoglobulins. DNA which did not hybridize with human DNA was detected by this method in sera containing hepatitis B virus used as a model system. (Auth.)

  9. The strategy of discrimination between flavors for detection of cosmogenic neutrinos

    Science.gov (United States)

    Lai, Kwang-Chang; Chen, Chih-Ching; Chen, Pisin

    2014-04-01

    We propose a new method to identify flavors of ultra high energy cosmic neutrinos. Energy loss of leptons in matter provides important information for the detection of neutrinos originated from high energy astrophysical sources. About 50 years ago, Askaryan proposed to detect Cherenkov signals by radio wave from the negative charge excess of particle showers. The theory of Cherenkov pulses with Fraunhofer approximation was widely studied in the past two decades. However, at high energies or for high density materials, electromagnetic shower should be elongated due to the Landau-Pomeranchuck-Migdal (LPM) effect. As such the standard Fraunhofer approximation ceases to be valid when the distance between the shower and the detector becomes comparable with the shower length. We have performed Monte Carlo simulations recently to investigate this regime based on the finite-difference time-domain (FDTD) method, and modified time domain integration method. In this work, we adopt the deduced relationship between the radio signal and the cascade development profile to investigate its implication to lepton signatures. Our method provides a straightforward technique to identify the neutrino flavor through the detected Cherenkov signals.

  10. A sensitive electrochemical aptasensor for ATP detection based on exonuclease III-assisted signal amplification strategy.

    Science.gov (United States)

    Bao, Ting; Shu, Huawei; Wen, Wei; Zhang, Xiuhua; Wang, Shengfu

    2015-03-03

    A target-induced structure-switching electrochemical aptasensor for sensitive detection of ATP was successfully constructed which was based on exonuclease III-catalyzed target recycling for signal amplification. With the existence of ATP, methylene blue (MB) labeled hairpin DNA formed G-quadruplex with ATP, which led to conformational changes of the hairpin DNA and created catalytic cleavage sites for exonuclease III (Exo III). Then the structure-switching DNA hybridized with capture DNA which made MB close to electrode surface. Meanwhile, Exo III selectively digested aptamer from its 3'-end, thus G-quadruplex structure was destroyed and ATP was released for target recycling. The Exo III-assisted target recycling amplified electrochemical signal significantly. Fluorescence experiment was performed to confirm the structure-switching process of the hairpin DNA. In fluorescence experiment, AuNPs-aptamer conjugates were synthesized, AuNPs quenched fluorescence of MB, the target-induced structure-switching made Exo III digested aptamer, which restored fluorescence. Under optimized conditions, the proposed aptasensor showed a linear range of 0.1-20 nM with a detection limit of 34 pM. In addition, the proposed aptasensor had good stability and selectivity, offered promising choice for the detection of other small molecules. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. A New Strategy to Reduce Influenza Escape: Detecting Therapeutic Targets Constituted of Invariance Groups

    Directory of Open Access Journals (Sweden)

    Julie Lao

    2017-03-01

    Full Text Available The pathogenicity of the different flu species is a real public health problem worldwide. To combat this scourge, we established a method to detect drug targets, reducing the possibility of escape. Besides being able to attach a drug candidate, these targets should have the main characteristic of being part of an essential viral function. The invariance groups that are sets of residues bearing an essential function can be detected genetically. They consist of invariant and synthetic lethal residues (interdependent residues not varying or slightly varying when together. We analyzed an alignment of more than 10,000 hemagglutinin sequences of influenza to detect six invariance groups, close in space, and on the protein surface. In parallel we identified five potential pockets on the surface of hemagglutinin. By combining these results, three potential binding sites were determined that are composed of invariance groups located respectively in the vestigial esterase domain, in the bottom of the stem and in the fusion area. The latter target is constituted of residues involved in the spring-loaded mechanism, an essential step in the fusion process. We propose a model describing how this potential target could block the reorganization of the hemagglutinin HA2 secondary structure and prevent viral entry into the host cell.

  12. Optimizing detection of noble gas emission at a former UNE site: sample strategy, collection, and analysis

    Science.gov (United States)

    Kirkham, R.; Olsen, K.; Hayes, J. C.; Emer, D. F.

    2013-12-01

    Underground nuclear tests may be first detected by seismic or air samplers operated by the CTBTO (Comprehensive Nuclear-Test-Ban Treaty Organization). After initial detection of a suspicious event, member nations may call for an On-Site Inspection (OSI) that in part, will sample for localized releases of radioactive noble gases and particles. Although much of the commercially available equipment and methods used for surface and subsurface environmental sampling of gases can be used for an OSI scenario, on-site sampling conditions, required sampling volumes and establishment of background concentrations of noble gases require development of specialized methodologies. To facilitate development of sampling equipment and methodologies that address OSI sampling volume and detection objectives, and to collect information required for model development, a field test site was created at a former underground nuclear explosion site located in welded volcanic tuff. A mixture of SF-6, Xe127 and Ar37 was metered into 4400 m3 of air as it was injected into the top region of the UNE cavity. These tracers were expected to move towards the surface primarily in response to barometric pumping or through delayed cavity pressurization (accelerated transport to minimize source decay time). Sampling approaches compared during the field exercise included sampling at the soil surface, inside surface fractures, and at soil vapor extraction points at depths down to 2 m. Effectiveness of various sampling approaches and the results of tracer gas measurements will be presented.

  13. Strategies for detecting colon cancer in patients with inflammatory bowel disease.

    Science.gov (United States)

    Bye, William A; Nguyen, Tran M; Parker, Claire E; Jairath, Vipul; East, James E

    2017-09-18

    Patients with longstanding ulcerative colitis and colonic Crohn's disease have an increased risk of colorectal cancer (CRC) compared with the general population. This review assessed the evidence that endoscopic surveillance may prolong life by allowing earlier detection of CRC or its pre-cursor lesion, dysplasia, in patients with inflammatory bowel disease (IBD). To assess the effectiveness of cancer surveillance programs for diagnosis of IBD-associated colorectal cancer and in reducing the mortality rate from colorectal cancer in patients with IBD. We searched MEDLINE, EMBASE, CENTRAL and clinical clinicaltrials.gov from inception to 19 September 2016. We also searched conference abstracts and reference lists to identify additional studies. Potentially relevant articles were reviewed independently and unblinded by two authors to determine eligibility. Randomised controlled trials (RCTs) or observational studies (cohort or case control) assessing any form of endoscopic surveillance aimed at early detection of CRC were considered for inclusion. Studies had to have a no surveillance comparison group to be eligible for inclusion. Eligible studies were reviewed in duplicate and the results of the primary research trials were independently extracted by two authors. The primary outcome was detection of CRC. Secondary outcomes included death from CRC, time to cancer detection, time to death and adverse events. Deaths from CRC were derived from life tables, survival curves or where possible, by calculating life tables from the data provided. The presence of significant heterogeneity among studies was tested by the chi-square test. Because this is a relatively insensitive test, a P value of less than 0.1 was considered statistically significant. Provided statistical heterogeneity was not present, the fixed effects model was used for the pooling of data. The 2x2 tables were combined into a summary test statistic using the pooled odds ratio (OR) and 95% confidence intervals

  14. A Dynamic Model for the Evaluation of Aircraft Engine Icing Detection and Control-Based Mitigation Strategies

    Science.gov (United States)

    Simon, Donald L.; Rinehart, Aidan W.; Jones, Scott M.

    2017-01-01

    Aircraft flying in regions of high ice crystal concentrations are susceptible to the buildup of ice within the compression system of their gas turbine engines. This ice buildup can restrict engine airflow and cause an uncommanded loss of thrust, also known as engine rollback, which poses a potential safety hazard. The aviation community is conducting research to understand this phenomena, and to identify avoidance and mitigation strategies to address the concern. To support this research, a dynamic turbofan engine model has been created to enable the development and evaluation of engine icing detection and control-based mitigation strategies. This model captures the dynamic engine response due to high ice water ingestion and the buildup of ice blockage in the engines low pressure compressor. It includes a fuel control system allowing engine closed-loop control effects during engine icing events to be emulated. The model also includes bleed air valve and horsepower extraction actuators that, when modulated, change overall engine operating performance. This system-level model has been developed and compared against test data acquired from an aircraft turbofan engine undergoing engine icing studies in an altitude test facility and also against outputs from the manufacturers customer deck. This paper will describe the model and show results of its dynamic response under open-loop and closed-loop control operating scenarios in the presence of ice blockage buildup compared against engine test cell data. Planned follow-on use of the model for the development and evaluation of icing detection and control-based mitigation strategies will also be discussed. The intent is to combine the model and control mitigation logic with an engine icing risk calculation tool capable of predicting the risk of engine icing based on current operating conditions. Upon detection of an operating region of risk for engine icing events, the control mitigation logic will seek to change the

  15. Event detection and exception handling strategies in the ASDEX Upgrade discharge control system

    International Nuclear Information System (INIS)

    Treutterer, W.; Neu, G.; Rapson, C.; Raupp, G.; Zasche, D.; Zehetbauer, T.

    2013-01-01

    Highlights: •Event detection and exception handling is integrated in control system architecture. •Pulse control with local exception handling and pulse supervision with central exception handling are strictly separated. •Local exception handling limits the effect of an exception to a minimal part of the controlled system. •Central Exception Handling solves problems requiring coordinated action of multiple control components. -- Abstract: Thermonuclear plasmas are governed by nonlinear characteristics: plasma operation can be classified into scenarios with pronounced features like L and H-mode, ELMs or MHD activity. Transitions between them may be treated as events. Similarly, technical systems are also subject to events such as failure of measurement sensors, actuator saturation or violation of machine and plant operation limits. Such situations often are handled with a mixture of pulse abortion and iteratively improved pulse schedule reference programming. In case of protection-relevant events, however, the complexity of even a medium-sized device as ASDEX Upgrade requires a sophisticated and coordinated shutdown procedure rather than a simple stop of the pulse. The detection of events and their intelligent handling by the control system has been shown to be valuable also in terms of saving experiment time and cost. This paper outlines how ASDEX Upgrade's discharge control system (DCS) detects events and handles exceptions in two stages: locally and centrally. The goal of local exception handling is to limit the effect of an unexpected or asynchronous event to a minimal part of the controlled system. Thus, local exception handling facilitates robustness to failures but keeps the decision structures lean. A central state machine deals with exceptions requiring coordinated action of multiple control components. DCS implements the state machine by means of pulse schedule segments containing pre-programmed waveforms to define discharge goal and control

  16. Event detection and exception handling strategies in the ASDEX Upgrade discharge control system

    Energy Technology Data Exchange (ETDEWEB)

    Treutterer, W., E-mail: Wolfgang.Treutterer@ipp.mpg.de; Neu, G.; Rapson, C.; Raupp, G.; Zasche, D.; Zehetbauer, T.

    2013-10-15

    Highlights: •Event detection and exception handling is integrated in control system architecture. •Pulse control with local exception handling and pulse supervision with central exception handling are strictly separated. •Local exception handling limits the effect of an exception to a minimal part of the controlled system. •Central Exception Handling solves problems requiring coordinated action of multiple control components. -- Abstract: Thermonuclear plasmas are governed by nonlinear characteristics: plasma operation can be classified into scenarios with pronounced features like L and H-mode, ELMs or MHD activity. Transitions between them may be treated as events. Similarly, technical systems are also subject to events such as failure of measurement sensors, actuator saturation or violation of machine and plant operation limits. Such situations often are handled with a mixture of pulse abortion and iteratively improved pulse schedule reference programming. In case of protection-relevant events, however, the complexity of even a medium-sized device as ASDEX Upgrade requires a sophisticated and coordinated shutdown procedure rather than a simple stop of the pulse. The detection of events and their intelligent handling by the control system has been shown to be valuable also in terms of saving experiment time and cost. This paper outlines how ASDEX Upgrade's discharge control system (DCS) detects events and handles exceptions in two stages: locally and centrally. The goal of local exception handling is to limit the effect of an unexpected or asynchronous event to a minimal part of the controlled system. Thus, local exception handling facilitates robustness to failures but keeps the decision structures lean. A central state machine deals with exceptions requiring coordinated action of multiple control components. DCS implements the state machine by means of pulse schedule segments containing pre-programmed waveforms to define discharge goal and control

  17. A study of redundancy management strategy for tetrad strap-down inertial systems. [error detection codes

    Science.gov (United States)

    Hruby, R. J.; Bjorkman, W. S.; Schmidt, S. F.; Carestia, R. A.

    1979-01-01

    Algorithms were developed that attempt to identify which sensor in a tetrad configuration has experienced a step failure. An algorithm is also described that provides a measure of the confidence with which the correct identification was made. Experimental results are presented from real-time tests conducted on a three-axis motion facility utilizing an ortho-skew tetrad strapdown inertial sensor package. The effects of prediction errors and of quantization on correct failure identification are discussed as well as an algorithm for detecting second failures through prediction.

  18. Strategies for leukemic biomarker detection using long-range surface plasmon-polaritons

    Science.gov (United States)

    Krupin, O.; Wang, C.; Berini, P.

    2014-09-01

    The suitability and use of long-range surface plasmon-polaritons for leukemic biomarker detection is discussed. A novel optical biosensor comprised of gold straight waveguides embedded in CYTOP with an etched microfluidic channel was tested for detecting leukemia in patient serum. Gold surface functionalization involved the interaction of protein G (PG) with antibodies by first adsorbing PG on bare gold and then antibodies (Immunoglobulin G, IgG). Differentiation between healthy and leukemia patients was based on the difference in ratios of Ig kappa (Igκ) and Ig lambda (Igλ) light chains in both serums. The ratio for a normal patient is ~1.4 - 2, whereas for a leukemia patient this ratio is altered. As a receptor (primary antibodies), goat anti-human anti-IgGκ and anti-IgGλ were used to functionalize the surface. Diluted normal and leukemia patient serums were tested over the aforementioned surfaces. The ratios of mass surface densities of IgGκ:IgGλ for normal serum (NS) and patient serum (PS) were found to be 1.55 and 1.92 respectively.

  19. Strategies for improving early detection and diagnosis of neovascular age-related macular degeneration

    Directory of Open Access Journals (Sweden)

    Keane PA

    2015-02-01

    Full Text Available Pearse A Keane,1 Gabriella de Salvo,2 Dawn A Sim,1 Srini Goverdhan,2 Rupesh Agrawal,1 Adnan Tufail1 1NIHR Biomedical Research Centre for Ophthalmology, Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, 2Department of Ophthalmology, University Hospital Southampton NHS Foundation Trust, Southampton, UK Abstract: Treatment of the neovascular form of age-related macular degeneration (AMD has been revolutionized by the introduction of such agents as ranibizumab, bevacizumab, and aflibercept. As a result, the incidence of legal blindness occurring secondary to AMD has fallen dramatically in recent years in many countries. While these agents have undoubtedly been successful in reducing visual impairment and blindness, patients with neovascular AMD typically lose some vision over time, and often lose the ability to read, drive, or perform other important activities of daily living. Efforts are therefore under way to develop strategies that allow for earlier detection and treatment of this disease. In this review, we begin by providing an overview of the rationale for, and the benefits of, early detection and treatment of neovascular AMD. To achieve this, we begin by providing an overview of the pathophysiology and natural history of choroidal neovascularization, before reviewing the evidence from both clinical trials and “real-world” outcome studies. We continue by highlighting an area that is often overlooked: the importance of patient education and awareness for early AMD detection. We conclude the review by reviewing an array of both established and emerging technologies for early detection of choroidal neovascularization, ranging from Amsler chart testing, to hyperacuity testing, to advanced imaging techniques, such as optical coherence tomography. Keywords: Amsler, detection, choroidal neovascularization, hyperacuity, optical coherence tomography

  20. Recent changes in stratospheric aerosol budget from ground-based and satellite observations

    Science.gov (United States)

    Khaykin, Sergey; Godin-Beekmann, Sophie; Keckhut, Philippe; Hauchecorne, Alain; Portafaix, Thierry; Begue, Nelson; Vernier, Jean-Paul; DeLand, Matthew; Bhartia, Pawan K.; Leblanc, Thierry

    2017-04-01

    Stratospheric aerosol budget plays an important role in climate variability and ozone chemistry. Observations of stratospheric aerosol by ground-based lidars represent a particular value as they ensure the continuity and coherence of stratospheric aerosol record. Ground-based lidars remain indispensable for complementing and validating satellite instruments and for filling gaps between satellite missions. On the other hand, geophysical interpretation of local observations is complicated without the knowledge of global distribution of stratospheric aerosol, which calls for a combined analysis of ground-based and space-borne observations. The present study aims at characterizing global and regional variability of stratospheric aerosol over the last 5 years using various sets of observations. We use the data provided by three lidars operated within NDACC (Network for Detection of Atmospheric Composition Change) at Haute-Provence, (44° N), Mauna Loa (21° N) and Maido (21° S) sites together with quasi-global-coverage aerosol measurements by CALIOP and OMPS satellite instruments. The local and space-borne measurements are shown to be in good agreement allowing for their synergetic use. Since the late 2012 stratospheric aerosol remained at background levels throughout the globe. Eruptions of Kelud volcano at 4° S in February 2014 and Calbuco volcano at 41° S in April 2015 resulted in a remarkable enhancement of stratospheric AOD at a wide latitude range. We explore meridional dispersion and lifetime of volcanic plumes in consideration of global atmospheric circulation. A focus is made on the poleward transport of volcanic aerosol and its detection at the mid-latitude Haute-Provence observatory. We show that the moderate eruptions in the Southern hemisphere leave a measurable imprint on the Northern mid-latitude aerosol loading. Having identified the volcanically-perturbed periods from local and global observations we examine the evolution of non-volcanic (background

  1. Tailored enrichment strategy detects low abundant small noncoding RNAs in HIV-1 infected cells

    Science.gov (United States)

    2012-01-01

    Background The various classes of small noncoding RNAs (sncRNAs) are important regulators of gene expression across divergent types of organisms. While a rapidly increasing number of sncRNAs has been identified over recent years, the isolation of sncRNAs of low abundance remains challenging. Virally encoded sncRNAs, particularly those of RNA viruses, can be expressed at very low levels. This is best illustrated by HIV-1 where virus encoded sncRNAs represent approximately 0.1-1.0% of all sncRNAs in HIV-1 infected cells or were found to be undetected. Thus, we applied a novel, sequence targeted enrichment strategy to capture HIV-1 derived sncRNAs in HIV-1 infected primary CD4+ T-lymphocytes and macrophages that allows a greater than 100-fold enrichment of low abundant sncRNAs. Results Eight hundred and ninety-two individual HIV-1 sncRNAs were cloned and sequenced from nine different sncRNA libraries derived from five independent experiments. These clones represent up to 90% of all sncRNA clones in the generated libraries. Two hundred and sixteen HIV-1 sncRNAs were distinguishable as unique clones. They are spread throughout the HIV-1 genome, however, forming certain clusters, and almost 10% show an antisense orientation. The length of HIV-1 sncRNAs varies between 16 and 89 nucleotides with an unexpected peak at 31 to 50 nucleotides, thus, longer than cellular microRNAs or short-interfering RNAs (siRNAs). Exemplary HIV-1 sncRNAs were also generated in cells infected with different primary HIV-1 isolates and can inhibit HIV-1 replication. Conclusions HIV-1 infected cells generate virally encoded sncRNAs, which might play a role in the HIV-1 life cycle. Furthermore, the enormous capacity to enrich low abundance sncRNAs in a sequence specific manner highly recommends our selection strategy for any type of investigation where origin or target sequences of the sought-after sncRNAs are known. PMID:22458358

  2. Selective and Sensitive Detection of Cyanide Based on the Displacement Strategy Using a Water-Soluble Fluorescent Probe

    Science.gov (United States)

    La, Ming; Hao, Yuanqiang; Wang, Zhaoyang; Han, Guo-Cheng; Qu, Lingbo

    2016-01-01

    A water-soluble fluorescent probe (C-GGH) was used for the highly sensitive and selective detection of cyanide (CN−) in aqueous media based on the displacement strategy. Due to the presence of the recognition unit GGH (Gly-Gly-His), the probe C-GGH can coordinate with Cu2+ and consequently display ON-OFF type fluorescence response. Furthermore, the in situ formed nonfluorescent C-GGH-Cu2+ complex can act as an effective OFF-ON type fluorescent probe for sensing CN− anion. Due to the strong binding affinity of CN− to Cu2+, CN− can extract Cu2+ from C-GGH-Cu2+ complex, leading to the release of C-GGH and the recovery of fluorescent emission of the system. The probe C-GGH-Cu2+ allowed detection of CN− in aqueous solution with a LOD (limit of detection) of 0.017 μmol/L which is much lower than the maximum contaminant level (1.9 μmol/L) for CN− in drinking water set by the WHO (World Health Organization). The probe also displayed excellent specificity for CN− towards other anions, including F−, Cl−, Br−, I−, SCN−, PO4 3−, N3 −, NO3 −, AcO−, SO4 2−, and CO3 2−. PMID:26881185

  3. Selective and Sensitive Detection of Cyanide Based on the Displacement Strategy Using a Water-Soluble Fluorescent Probe

    Directory of Open Access Journals (Sweden)

    Ming La

    2016-01-01

    Full Text Available A water-soluble fluorescent probe (C-GGH was used for the highly sensitive and selective detection of cyanide (CN− in aqueous media based on the displacement strategy. Due to the presence of the recognition unit GGH (Gly-Gly-His, the probe C-GGH can coordinate with Cu2+ and consequently display ON-OFF type fluorescence response. Furthermore, the in situ formed nonfluorescent C-GGH-Cu2+ complex can act as an effective OFF-ON type fluorescent probe for sensing CN− anion. Due to the strong binding affinity of CN− to Cu2+, CN− can extract Cu2+ from C-GGH-Cu2+ complex, leading to the release of C-GGH and the recovery of fluorescent emission of the system. The probe C-GGH-Cu2+ allowed detection of CN− in aqueous solution with a LOD (limit of detection of 0.017 μmol/L which is much lower than the maximum contaminant level (1.9 μmol/L for CN− in drinking water set by the WHO (World Health Organization. The probe also displayed excellent specificity for CN− towards other anions, including F−, Cl−, Br−, I−, SCN−, PO43-, N3-, NO3-, AcO−, SO42-, and CO32-.

  4. A metabonomic strategy for the detection of the metabolic effects of chamomile (Matricaria recutita L.) ingestion.

    Science.gov (United States)

    Wang, Yulan; Tang, Huiru; Nicholson, Jeremy K; Hylands, Peter J; Sampson, J; Holmes, Elaine

    2005-01-26

    A metabonomic strategy, utilizing high-resolution 1H NMR spectroscopy in conjunction with chemometric methods (discriminant analysis with orthogonal signal correction), has been applied to the study of human biological responses to chamomile tea ingestion. Daily urine samples were collected from volunteers during a 6-week period incorporating a 2-week baseline period, 2 weeks of daily chamomile tea ingestion, and a 2-week post-treatment phase. Although strong intersubject variation in metabolite profiles was observed, clear differentiation between the samples obtained before and after chamomile ingestion was achieved on the basis of increased urinary excretion of hippurate and glycine with depleted creatinine concentration. Samples obtained up to 2 weeks after daily chamomile intake formed an isolated cluster in the discriminant analysis map, from which it was inferred that the metabolic effects of chamomile ingestion were prolonged during the 2-week postdosing period. This study highlights the potential for metabonomic technology in the assessment of nutritional interventions, despite the high degree of variation from genetic and environmental sources.

  5. Newborn hearing screening and strategy for early detection of hearing loss in infants.

    Science.gov (United States)

    Jakubíková, Janka; Kabátová, Zuzana; Pavlovcinová, Gabriela; Profant, Milan

    2009-04-01

    More than 80% of permanent hearing losses (HL) in children are congenital. Newborn hearing screening (NHS) is the best method for early detection of suspected hearing loss. If the NHS is not universal more than 30% permanent hearing losses are not identified. There are various methods of NHS: otoacoustic emissions (TEOAE, DPOAE) and automatic auditory brainstem response (AABR). After hearing screening, and when hearing loss is suspected, tympanometry and audiological methods then used for determination of hearing threshold; these include ABR, ASSR or/and behavioral methods. The goal of this study is to evaluate the influence of UNHS on the early detection of hearing loss in children before and after the implementation of obligatory universal newborn hearing screening in Slovakia, and also on the etiologic evaluation of hearing impaired infants identified by screening. In Slovakia NHS started in 1998 and was provided in ENT departments. From May 1, 2006 UNHS has been mandatory in Slovakia, using two stages TEOAE in all newborn departments in Slovakia (64 newborn departments). In year 2005--42% of newborns in Slovakia were screened, in 2006--66% newborns and in 2007--94, 99% (three small newborn departments do not yet have equipment for OAE screening). For determination of hearing thresholds ASSR are used in two ENT departments and ABR in the other four ENT departments. Comparing the number of identified cases with bilateral severe permanent HL or deafness before and after UNHS, 22.8% more cases of PHL were identified in the first year of UNHS. Also the average age of diagnosis of PHL was lower. In the year 2007, 94% of newborns were screened. We found 0.947/1000 newborns with bilateral severe PHL (35.9%) more than before UNHS). After audiologic and etiologic assessment of the 76 infants who failed screening, 5 (6.58%) were found to have normal hearing, 16 (22.54%) had unilateral and 55 (77.46%) had bilateral SNHL. A non-syndromic genetic cause was present in 25

  6. Surveillance strategies for detecting chronic wasting disease in free-ranging deer and elk: results of a CWD surveillance workshop

    Science.gov (United States)

    Samuel, Michael D.; Joly, Damien O.; Wild, Margaret A.; Wright, Scott D.; Otis, David L.; Werge, Rob W.; Miller, Michael W.

    2003-01-01

    Chronic Wasting Disease (CWD), a fatal brain disease of North American deer and elk, has recently emerged as an important wildlife management issue. Interest and concern over the spread of this disease and its potential impact on free-ranging cervid populations has increased with discovery of the disease in numerous states and provinces. Current studies suggest that CWD may adversely affect of these highly visible, socially desirable, and economically valuable species. Despite the lack of evidence that CWD affects humans or livestock, a significant concern has been the perceived risk to humans and livestock. Uncertainty about whether CWD poses a health risk to hunters and their families who consume venison has resulted in testing of free-ranging cervids for CWD. In response to many of these concerns, wildlife management agencies across the nation have undertaken surveillance programs to detect CWD in their cervid populations. The nation-wide costs for an extensive CWD surveillance program have been estimated at several million dollars. This document provides guidance on the development and conduct of scientifically sound surveillance programs to detect CWD in free-ranging deer and elk populations. These guidelines will not apply equally to all jurisdictions. In many cases local circumstances, resources, area(s) of concern, disease risk, animal and landscape ecology, political, social, and many other factors will influence the objectives, design, and conduct of CWD surveillance programs. Part I of this report discusses the importance of management goals, strategies, and disease risks in developing a surveillance program. Part II describes surveillance methods, steps in designing a sampling strategy to detect CWD, alternative collection methods, and statistical considerations. Part III describes costs (personnel, time, and money) associated with implementation of these plans that will influence program design. Part IV outlines research that is needed to further

  7. Investigations on fabricating strategies and utilization of rare earth based multicomponent oxide powders in radiation detection

    International Nuclear Information System (INIS)

    Shinde, Seema; Pitale, S.S.; Banthia, S.; Ghosh, M.; Tyagi, M.; Sen, S.; Gadkari, S.C.

    2014-01-01

    Materials containing rare earths demonstrate a broad field of applications as high energy radiation detectors, mainly due to their fascinating optical properties. Currently, Ce 3+ -doped rare earth silicates and garnets dominate the scintillator market because they show a high light yield, fast decay time, and high chemical stability. Moreover, the emission wavelength of silicates (410-440 nm) matches the wavelength sensitivity of conventional PMTs while, Si-photo-detector readouts are possible with garnets (emission near 550 nm). The composition, structure and phase of rare earth silicates are rather complex. For example, there are many phases like oxyorthosilicate R 2 SiO 5 , disilicate R 2 Si 2 O 7 , hexagonal R x (SiO 4 ) 6 O 2 oxyapatite etc (where R= Rare earth element). The controlled synthesis of single phase rare earth silicates and garnets nanomaterials is not easy and can only be reached with precisely controlled experimental conditions. In this work, we provide a broad overview of our recent scientific developments linked to a few aspects of synthesizing cerium activated rare earth based silicates and garnet materials, namely Gd 2 SiO 5 :Ce 3+ , Gd 4.67 (SiO 4 ) 3 O, Gd 2 Si 2 O 7 :Ce 3+ and Gd 3 Al x Ga 1-x O 12 :Ce 3+ (where 0≤x≤5) exploiting the advantages of solution combustion, chemical co-precipitation and hydrothermal techniques. A brief summary of results based on synthesis strategy adopted, composition, size shape and corresponding luminescence features of Gd based compounds are tabulated. The room temperature photoluminescence (PL) features of compounds listed. Efforts towards finding new properties and new materials will be continued and several applications, in particular energy-conversion and scintillator detectors, will benefit from these rare earth materials

  8. Modeling LIDAR Detection of Biological Aerosols to Determine Optimum Implementation Strategy

    Energy Technology Data Exchange (ETDEWEB)

    Sheen, David M.; Aker, Pam M.

    2007-09-19

    This report summarizes work performed for a larger multi-laboratory project named the Background Interferent Measurement and Standards project. While originally tasked to develop algorithms to optimize biological warfare agent detection using UV fluorescence LIDAR, the current uncertainties in the reported fluorescence profiles and cross sections the development of any meaningful models. It was decided that a better approach would be to model the wavelength-dependent elastic backscattering from a number of ambient background aerosol types, and compare this with that generated from representative sporulated and vegetative bacterial systems. Calculations in this report show that a 266, 355, 532 and 1064 nm elastic backscatter LIDAR experiment will allow an operator to immediately recognize when sulfate, VOC-based or road dust (silicate) aerosols are approaching, independent of humidity changes. It will be more difficult to distinguish soot aerosols from biological aerosols, or vegetative bacteria from sporulated bacteria. In these latter cases, the elastic scattering data will most likely have to be combined with UV fluorescence data to enable a more robust categorization.

  9. Detection and monitoring of volatile and semivolatile pollutants in soil through different sensing strategies

    Science.gov (United States)

    De Cesare, Fabrizio; Macagnano, Antonella

    2013-04-01

    Pollutants in environments are more and more threatening the maintenance of health of habitats and their inhabitants. A proper evaluation of the impact of contaminants from several different potential sources on soil quality and health and then on organisms living therein, and the possible and sometime probable related risk of transfer of pollutants, with their toxic effects, to organisms living in different environmental compartments, through the trophic chain up to humans is strongly required by decision makers, in order to promptly take adequate actions to prevent environmental and health damages and monitor the exposure rate of individuals to toxicants. Then, a reliable detection of pollutants in environments and the monitoring of dynamics and fate of contaminants therein are of utmost importance to achieve this goal. In soil, chemical and physical techniques to detect pollutants have been well known for decades, but can often drive to both over- and underestimations of the actual bioavailable (and then toxic) fraction of contaminants, and then of the real risk for organisms, deriving from their presence therein. The use of bioindicators (both living organisms and enzyme activities somehow derived from them) can supply more reliable information about the quantification of the bioavailable fraction of soil pollutants. In the last decades, a physicochemical technique, such as SPME (solid phase microextraction) followed by GC-MS analysis, has been demonstrated to provide similar results to those obtained from some pedofaunal populations, used as bioindicators, as concerns the bioavailable pollutant quantification in soil. More recently, we have applied a sensing technology, namely electronic nose (EN), which comprises several unspecific sensors arranged in an array and that is capable of providing more qualitative than quantitative information about complex air samples, to the study of soils contaminated with semivolatile (SVOCs) pollutants, such as polycyclic

  10. Proceedings of the 2011 Monitoring Research Review: Ground-Based Nuclear Explosion Monitoring Technologies

    International Nuclear Information System (INIS)

    Wetovsky, Marvin A.; Patterson, Eileen F.; Sandoval, Marisa N.

    2011-01-01

    These proceedings contain papers prepared for the Monitoring Research Review 2011: Ground-Based Nuclear Explosion Monitoring Technologies, held 13-15 September, 2011 in Tucson, Arizona. These papers represent the combined research related to ground-based nuclear explosion monitoring funded by the National Nuclear Security Administration (NNSA), Defense Threat Reduction Agency (DTRA), Air Force Research Laboratory (AFRL), US Army Space and Missile Defense Command, Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO), National Science Foundation (NSF), and other invited sponsors. The scientific objectives of the research are to improve the United States' capability to detect, locate, and identify nuclear explosions. The purpose of the meeting is to provide the sponsoring agencies, as well as potential users, an opportunity to review research accomplished during the preceding year and to discuss areas of investigation for the coming year. For the researchers, it provides a forum for the exchange of scientific information toward achieving program goals, and an opportunity to discuss results and future plans. Paper topics include: seismic regionalization and calibration; detection and location of sources; wave propagation from source to receiver; the nature of seismic sources, including mining practices; hydroacoustic, infrasound, and radionuclide methods; on-site inspection; and data processing.

  11. Proceedings of the 2011 Monitoring Research Review: Ground-Based Nuclear Explosion Monitoring Technologies

    Energy Technology Data Exchange (ETDEWEB)

    Wetovsky, Marvin A. [Editor; Patterson, Eileen F. [Editor; Sandoval, Marisa N. [Editor

    2011-09-13

    These proceedings contain papers prepared for the Monitoring Research Review 2011: Ground-Based Nuclear Explosion Monitoring Technologies, held 13-15 September, 2011 in Tucson, Arizona. These papers represent the combined research related to ground-based nuclear explosion monitoring funded by the National Nuclear Security Administration (NNSA), Defense Threat Reduction Agency (DTRA), Air Force Research Laboratory (AFRL), US Army Space and Missile Defense Command, Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO), National Science Foundation (NSF), and other invited sponsors. The scientific objectives of the research are to improve the United States' capability to detect, locate, and identify nuclear explosions. The purpose of the meeting is to provide the sponsoring agencies, as well as potential users, an opportunity to review research accomplished during the preceding year and to discuss areas of investigation for the coming year. For the researchers, it provides a forum for the exchange of scientific information toward achieving program goals, and an opportunity to discuss results and future plans. Paper topics include: seismic regionalization and calibration; detection and location of sources; wave propagation from source to receiver; the nature of seismic sources, including mining practices; hydroacoustic, infrasound, and radionuclide methods; on-site inspection; and data processing.

  12. Proceedings of the 28th Seismic Research Review: Ground-Based Nuclear Explosion Monitoring Technologies

    International Nuclear Information System (INIS)

    Wetovsky, Marvin A.; Benson, Jody; Patterson, Eileen F.

    2006-01-01

    These proceedings contain papers prepared for the 28th Seismic Research Review: Ground-Based Nuclear Explosion Monitoring Technologies, held 19-21 September, 2006 in Orlando, Florida. These papers represent the combined research related to ground-based nuclear explosion monitoring funded by the National Nuclear Security Administration (NNSA), Air Force Technical Applications Center (AFTAC), Air Force Research Laboratory (AFRL), US Army Space and Missile Defense Command, Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO), and other invited sponsors. The scientific objectives of the research are to improve the United States capability to detect, locate, and identify nuclear explosions. The purpose of the meeting is to provide the sponsoring agencies, as well as potential users, an opportunity to review research accomplished during the preceding year and to discuss areas of investigation for the coming year. For the researchers, it provides a forum for the exchange of scientific information toward achieving program goals, and an opportunity to discuss results and future plans. Paper topics include: seismic regionalization and calibration; detection and location of sources; wave propagation from source to receiver; the nature of seismic sources, including mining practices; hydroacoustic, infrasound, and radionuclide methods; on-site inspection; and data processing.

  13. Proceedings of the 28th Seismic Research Review: Ground-Based Nuclear Explosion Monitoring Technologies

    Energy Technology Data Exchange (ETDEWEB)

    Wetovsky, Marvin A. [Editor; Benson, Jody [Editor; Patterson, Eileen F. [Editor

    2006-09-19

    These proceedings contain papers prepared for the 28th Seismic Research Review: Ground-Based Nuclear Explosion Monitoring Technologies, held 19-21 September, 2006 in Orlando, Florida. These papers represent the combined research related to ground-based nuclear explosion monitoring funded by the National Nuclear Security Administration (NNSA), Air Force Technical Applications Center (AFTAC), Air Force Research Laboratory (AFRL), US Army Space and Missile Defense Command, Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO), and other invited sponsors. The scientific objectives of the research are to improve the United States capability to detect, locate, and identify nuclear explosions. The purpose of the meeting is to provide the sponsoring agencies, as well as potential users, an opportunity to review research accomplished during the preceding year and to discuss areas of investigation for the coming year. For the researchers, it provides a forum for the exchange of scientific information toward achieving program goals, and an opportunity to discuss results and future plans. Paper topics include: seismic regionalization and calibration; detection and location of sources; wave propagation from source to receiver; the nature of seismic sources, including mining practices; hydroacoustic, infrasound, and radionuclide methods; on-site inspection; and data processing.

  14. Proceedings of the 27th Seismic Research Review: Ground-Based Nuclear Explosion Monitoring Technologies

    Energy Technology Data Exchange (ETDEWEB)

    Wetovsky, Marvin A. [Editor; Benson, Jody [Editor; Patterson, Eileen F. [Editor

    2005-09-20

    These proceedings contain papers prepared for the 27th Seismic Research Review: Ground-Based Nuclear Explosion Monitoring Technologies, held 20-22 September, 2005 in Rancho Mirage, California. These papers represent the combined research related to ground-based nuclear explosion monitoring funded by the National Nuclear Security Administration (NNSA), Air Force Technical Applications Center (AFTAC), Air Force Research Laboratory (AFRL), US Army Space and Missile Defense Command, and other invited sponsors. The scientific objectives of the research are to improve the United States capability to detect, locate, and identify nuclear explosions. The purpose of the meeting is to provide the sponsoring agencies, as well as potential users, an opportunity to review research accomplished during the preceding year and to discuss areas of investigation for the coming year. For the researchers, it provides a forum for the exchange of scientific information toward achieving program goals, and an opportunity to discuss results and future plans. Paper topics include: seismic regionalization and calibration; detection and location of sources; wave propagation from source to receiver; the nature of seismic sources, including mining practices; hydroacoustic, infrasound, and radionuclide methods; on-site inspection; and data processing.

  15. Proceedings of the 29th Monitoring Research Review: Ground-Based Nuclear Explosion Monitoring Technologies

    International Nuclear Information System (INIS)

    Wetovsky, Marvin A.; Benson, Jody; Patterson, Eileen F.

    2007-01-01

    These proceedings contain papers prepared for the 29th Monitoring Research Review: Ground-Based Nuclear Explosion Monitoring Technologies, held 25-27 September, 2007 in Denver, Colorado. These papers represent the combined research related to ground-based nuclear explosion monitoring funded by the National Nuclear Security Administration (NNSA), Air Force Technical Applications Center (AFTAC), Air Force Research Laboratory (AFRL), US Army Space and Missile Defense Command, Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO), and other invited sponsors. The scientific objectives of the research are to improve the United States capability to detect, locate, and identify nuclear explosions. The purpose of the meeting is to provide the sponsoring agencies, as well as potential users, an opportunity to review research accomplished during the preceding year and to discuss areas of investigation for the coming year. For the researchers, it provides a forum for the exchange of scientific information toward achieving program goals, and an opportunity to discuss results and future plans. Paper topics include: seismic regionalization and calibration; detection and location of sources; wave propagation from source to receiver; the nature of seismic sources, including mining practices; hydroacoustic, infrasound, and radionuclide methods; on-site inspection; and data processing.

  16. Proceedings of the 27th Seismic Research Review: Ground-Based Nuclear Explosion Monitoring Technologies

    International Nuclear Information System (INIS)

    Wetovsky, Marvin A.; Benson, Jody; Patterson, Eileen F.

    2005-01-01

    These proceedings contain papers prepared for the 27th Seismic Research Review: Ground-Based Nuclear Explosion Monitoring Technologies, held 20-22 September, 2005 in Rancho Mirage, California. These papers represent the combined research related to ground-based nuclear explosion monitoring funded by the National Nuclear Security Administration (NNSA), Air Force Technical Applications Center (AFTAC), Air Force Research Laboratory (AFRL), US Army Space and Missile Defense Command, and other invited sponsors. The scientific objectives of the research are to improve the United States capability to detect, locate, and identify nuclear explosions. The purpose of the meeting is to provide the sponsoring agencies, as well as potential users, an opportunity to review research accomplished during the preceding year and to discuss areas of investigation for the coming year. For the researchers, it provides a forum for the exchange of scientific information toward achieving program goals, and an opportunity to discuss results and future plans. Paper topics include: seismic regionalization and calibration; detection and location of sources; wave propagation from source to receiver; the nature of seismic sources, including mining practices; hydroacoustic, infrasound, and radionuclide methods; on-site inspection; and data processing.

  17. Proceedings of the 30th Monitoring Research Review: Ground-Based Nuclear Explosion Monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Wetovsky, Marv A [Los Alamos National Laboratory; Aguilar-chang, Julio [Los Alamos National Laboratory; Arrowsmith, Marie [Los Alamos National Laboratory; Arrowsmith, Stephen [Los Alamos National Laboratory; Baker, Diane [Los Alamos National Laboratory; Begnaud, Michael [Los Alamos National Laboratory; Harste, Hans [Los Alamos National Laboratory; Maceira, Monica [Los Alamos National Laboratory; Patton, Howard [Los Alamos National Laboratory; Phillips, Scott [Los Alamos National Laboratory; Randall, George [Los Alamos National Laboratory; Revelle, Douglas [Los Alamos National Laboratory; Rowe, Charlotte [Los Alamos National Laboratory; Stead, Richard [Los Alamos National Laboratory; Steck, Lee [Los Alamos National Laboratory; Whitaker, Rod [Los Alamos National Laboratory; Yang, Xiaoning [Los Alamos National Laboratory

    2008-09-23

    These proceedings contain papers prepared for the 30th Monitoring Research Review: Ground-Based Nuclear Explosion Monitoring Technologies, held 23-25 September, 2008 in Portsmouth, Virginia. These papers represent the combined research related to ground-based nuclear explosion monitoring funded by the National Nuclear Security Administration (NNSA), Air Force Technical Applications Center (AFTAC), Air Force Research Laboratory (AFRL), US Army Space and Missile Defense Command, Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO), and other invited sponsors. The scientific objectives of the research are to improve the United States’ capability to detect, locate, and identify nuclear explosions. The purpose of the meeting is to provide the sponsoring agencies, as well as potential users, an opportunity to review research accomplished during the preceding year and to discuss areas of investigation for the coming year. For the researchers, it provides a forum for the exchange of scientific information toward achieving program goals, and an opportunity to discuss results and future plans. Paper topics include: seismic regionalization and calibration; detection and location of sources; wave propagation from source to receiver; the nature of seismic sources, including mining practices; hydroacoustic, infrasound, and radionuclide methods; on-site inspection; and data processing.

  18. Proceedings of the 2010 Monitoring Research Review: Ground-Based Nuclear Explosion Monitoring Technologies

    Energy Technology Data Exchange (ETDEWEB)

    Wetovsky, Marvin A [Editor; Patterson, Eileen F [Editor

    2010-09-21

    These proceedings contain papers prepared for the Monitoring Research Review 2010: Ground-Based Nuclear Explosion Monitoring Technologies, held 21-23 September, 2010 in Orlando, Florida,. These papers represent the combined research related to ground-based nuclear explosion monitoring funded by the National Nuclear Security Administration (NNSA), Air Force Research Laboratory (AFRL), US Army Space and Missile Defense Command, National Science Foundation (NSF), Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO), and other invited sponsors. The scientific objectives of the research are to improve the United States capability to detect, locate, and identify nuclear explosions. The purpose of the meeting is to provide the sponsoring agencies, as well as potential users, an opportunity to review research accomplished during the preceding year and to discuss areas of investigation for the coming year. For the researchers, it provides a forum for the exchange of scientific information toward achieving program goals, and an opportunity to discuss results and future plans. Paper topics include: seismic regionalization and calibration; detection and location of sources; wave propagation from source to receiver; the nature of seismic sources, including mining practices; hydroacoustic, infrasound, and radionuclide methods; on-site inspection; and data processing.

  19. Proceedings of the 29th Monitoring Research Review: Ground-Based Nuclear Explosion Monitoring Technologies

    Energy Technology Data Exchange (ETDEWEB)

    Wetovsky, Marvin A. [Editor; Benson, Jody [Editor; Patterson, Eileen F. [Editor

    2007-09-25

    These proceedings contain papers prepared for the 29th Monitoring Research Review: Ground-Based Nuclear Explosion Monitoring Technologies, held 25-27 September, 2007 in Denver, Colorado. These papers represent the combined research related to ground-based nuclear explosion monitoring funded by the National Nuclear Security Administration (NNSA), Air Force Technical Applications Center (AFTAC), Air Force Research Laboratory (AFRL), US Army Space and Missile Defense Command, Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO), and other invited sponsors. The scientific objectives of the research are to improve the United States capability to detect, locate, and identify nuclear explosions. The purpose of the meeting is to provide the sponsoring agencies, as well as potential users, an opportunity to review research accomplished during the preceding year and to discuss areas of investigation for the coming year. For the researchers, it provides a forum for the exchange of scientific information toward achieving program goals, and an opportunity to discuss results and future plans. Paper topics include: seismic regionalization and calibration; detection and location of sources; wave propagation from source to receiver; the nature of seismic sources, including mining practices; hydroacoustic, infrasound, and radionuclide methods; on-site inspection; and data processing.

  20. Proceedings of the 2010 Monitoring Research Review: Ground-Based Nuclear Explosion Monitoring Technologies

    International Nuclear Information System (INIS)

    Wetovsky, Marvin A.; Patterson, Eileen F.

    2010-01-01

    These proceedings contain papers prepared for the Monitoring Research Review 2010: Ground-Based Nuclear Explosion Monitoring Technologies, held 21-23 September, 2010 in Orlando, Florida,. These papers represent the combined research related to ground-based nuclear explosion monitoring funded by the National Nuclear Security Administration (NNSA), Air Force Research Laboratory (AFRL), US Army Space and Missile Defense Command, National Science Foundation (NSF), Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO), and other invited sponsors. The scientific objectives of the research are to improve the United States capability to detect, locate, and identify nuclear explosions. The purpose of the meeting is to provide the sponsoring agencies, as well as potential users, an opportunity to review research accomplished during the preceding year and to discuss areas of investigation for the coming year. For the researchers, it provides a forum for the exchange of scientific information toward achieving program goals, and an opportunity to discuss results and future plans. Paper topics include: seismic regionalization and calibration; detection and location of sources; wave propagation from source to receiver; the nature of seismic sources, including mining practices; hydroacoustic, infrasound, and radionuclide methods; on-site inspection; and data processing.

  1. Comparison of strategies for combining dynamic linear models with artificial neural networks for detecting diarrhea in slaughter pigs

    DEFF Research Database (Denmark)

    Jensen, Dan Børge; Kristensen, Anders Ringgaard

    2016-01-01

    The drinking behavior of healthy pigs is known to follow predictable diurnal patterns, and these patterns are further known to change in relation to undesired events such as diarrhea. We therefore expect that automatic monitoring of slaughter pig drinking behavior, combined with machine learning......, can provide early and automatic detection of diarrhea. To determine the best approach to achieve this goal, we compared 36 different strategies for combining a multivariate dynamic linear model (DLM) with an artificial neural network (ANN). We used data collected in 16 pens between November 2013...... and December 2014 at a commercial Danish pig farm. The pen level water flow (liters/hour/pig) and drinking bouts frequency (bouts/hour/pig) were monitored. Staff registrations of diarrhea were the events of interest. Mean water flow and drinking bouts frequency were each modeled using three harmonic waves...

  2. Capillary gel electrophoresis-coupled aptamer enzymatic cleavage protection strategy for the simultaneous detection of multiple small analytes.

    Science.gov (United States)

    Perrier, Sandrine; Zhu, Zhenyu; Fiore, Emmanuelle; Ravelet, Corinne; Guieu, Valérie; Peyrin, Eric

    2014-05-06

    This novel, multi small-analyte sensing strategy is the result of combining the target-induced aptamer enzymatic protection approach with the CGE-LIF (capillary gel electrophoresis with laser-induced fluorescence) technique. The implemented assay principle is based on an analysis of the phosphodiesterase I (PDE I)-mediated size variation of a fluorescein-labeled aptamer (FApt), the enzyme catalyzing the removal of nucleotides from DNA in the 3' to 5' direction. In the absence of the target, the unfolded aptamer was enzymatically cleaved into short DNA fragments. Upon target binding, the DNA substrate was partially protected against enzymatic hydrolysis. The amount of bound aptamer remaining after the exonuclease reaction was proportional to the concentration of the target. The CGE technique, which was used to determine the separation of FApt species from DNA digested products, permitted the quantification of adenosine (A), ochratoxin A (O), and tyrosinamide (T) under the same optimized enzymatic conditions. This assay strategy was subsequently applied to the simultaneous detection of A, O, and T in a single capillary under buffered conditions using corresponding FApt probes of different lengths (23, 36, and 49 nucleotides, respectively). Additionally, the detection of these three small molecules was successfully achieved in a complex medium (diluted, heat-treated human serum) showing a good recovery. It is worth noting that the multiplexed analysis was accomplished for targets with different charge states by using aptamers possessing various structural features. This sensing platform constitutes a rationalized and reliable approach with an expanded potential for a high-throughput determination of small analytes in a single capillary.

  3. Investigating the long-term evolution of subtropical ozone profiles applying ground-based FTIR spectrometry

    Directory of Open Access Journals (Sweden)

    O. E. García

    2012-11-01

    Full Text Available This study investigates the long-term evolution of subtropical ozone profile time series (1999–2010 obtained from ground-based FTIR (Fourier Transform InfraRed spectrometry at the Izaña Observatory ozone super-site. Different ozone retrieval strategies are examined, analysing the influence of an additional temperature retrieval and different constraints. The theoretical assessment reveals that the FTIR system is able to resolve four independent ozone layers with a precision of better than 6% in the troposphere and of better than 3% in the lower, middle and upper stratosphere. This total error includes the smoothing error, which dominates the random error budget. Furthermore, we estimate that the measurement noise as well as uncertainties in the applied atmospheric temperature profiles and instrumental line shape are leading error sources. We show that a simultaneous temperature retrieval can significantly reduce the total random errors and that a regular determination of the instrumental line shape is important for producing a consistent long-term dataset. These theoretical precision estimates are empirically confirmed by daily intercomparisons with Electro Chemical Cell (ECC sonde profiles. In order to empirically document the long-term stability of the FTIR ozone profile data we compare the linear trends and seasonal cycles as obtained from the FTIR and ECC time series. Concerning seasonality, in winter both techniques observe stratospheric ozone profiles that are typical middle latitude profiles (low tropopause, low ozone maximum concentrations and in summer/autumn profiles that are typical tropical profiles (high tropopause, high maximum concentrations. The linear trends estimated from the FTIR and the ECC datasets agree within their error bars. For the FTIR time series, we observe a significant negative trend in the upper troposphere/lower stratosphere of about −0.2% yr−1 and a significant positive trend in the middle and

  4. Comparing two types of perspective taking as strategies for detecting distress amongst parents of children with cancer: A randomised trial.

    Directory of Open Access Journals (Sweden)

    Lucie Gouveia

    Full Text Available To compare two perspective taking strategies on (i clinicians' ability to accurately identify negative thoughts and feelings of parents of children with cancer, and (ii clinician distress.Sixty-three hematology-oncology professionals and nursing students watched a video featuring parents of children with cancer. Participants were randomly assigned to one of two groups. In the imagine-self group, they were instructed to imagine the feelings and life consequences which they would experience if they were in the parents' position. In the imagine-other group, they were instructed to imagine the feelings and life consequences experienced by the parents. Parent-clinician agreement on thoughts/feelings was evaluated (standard stimulus paradigm. Clinician distress was also assessed.The intervention was effective in manipulating perspective type. The groups did not significantly differ on parent-clinician agreement. Concentrating on personal feelings (imagine-self strategy did predict lower agreement when controlling for trait empathy. Clinician distress was higher in the imagine-self group.Although the link between perspective type and detection of distress remains unclear, the results suggest that clinicians who highly focus on their own feelings tend to be less accurate on parental distress and experience more distress themselves.This research could potentially improve communication training and burnout prevention.

  5. Ground-Based Global Positioning System (GPS) Meteorology Integrated Precipitable Water Vapor (IPW)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Ground-Based Global Positioning System (GPS) Meteorology Integrated Precipitable Water Vapor (IPW) data set measures atmospheric water vapor using ground-based...

  6. Development of a Ground-Based Atmospheric Monitoring Network for the Global Mercury Observation System (GMOS

    Directory of Open Access Journals (Sweden)

    Sprovieri F.

    2013-04-01

    Full Text Available Consistent, high-quality measurements of atmospheric mercury (Hg are necessary in order to better understand Hg emissions, transport, and deposition on a global scale. Although the number of atmospheric Hg monitoring stations has increased in recent years, the available measurement database is limited and there are many regions of the world where measurements have not been extensively performed. Long-term atmospheric Hg monitoring and additional ground-based monitoring sites are needed in order to generate datasets that will offer new insight and information about the global scale trends of atmospheric Hg emissions and deposition. In the framework of the Global Mercury Observation System (GMOS project, a coordinated global observational network for atmospheric Hg is being established. The overall research strategy of GMOS is to develop a state-of-the-art observation system able to provide information on the concentration of Hg species in ambient air and precipitation on the global scale. This network is being developed by integrating previously established ground-based atmospheric Hg monitoring stations with newly established GMOS sites that are located both at high altitude and sea level locations, as well as in climatically diverse regions. Through the collection of consistent, high-quality atmospheric Hg measurement data, we seek to create a comprehensive assessment of atmospheric Hg concentrations and their dependence on meteorology, long-range atmospheric transport and atmospheric emissions.

  7. A general sensing strategy for detection of Fe{sup 3+} by using amino acid-modified graphene quantum dots as fluorescent probe

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Qi [College of Chemistry and Environmental Engineering, and Institute of Applied Chemistry, Shanxi Datong University, Datong, Shanxi, 037009 (China); Song, Jinping, E-mail: songjphxsxdt@163.com [College of Chemistry and Environmental Engineering, and Institute of Applied Chemistry, Shanxi Datong University, Datong, Shanxi, 037009 (China); Institute of Environmental Science, Shanxi University, Taiyuan, 030006 (China); Wang, Shangzhi; Yang, Jie; Guo, Yong [College of Chemistry and Environmental Engineering, and Institute of Applied Chemistry, Shanxi Datong University, Datong, Shanxi, 037009 (China); Dong, Chuan, E-mail: dc@sxu.edu.cn [Institute of Environmental Science, Shanxi University, Taiyuan, 030006 (China)

    2016-12-15

    Graphical abstract: Three kinds of amino acid-modified graphene quantum dots (GQDs) were synthesized through acylation and amination reactions. The as-synthesized GQDs can emit strong blue fluorescence. The presence of Fe{sup 3+} will cause obvious fluorescence quenching of the three kinds of GQDs. Based on these, a general sensing strategy for detection of Fe{sup 3+} was successfully developed. - Highlights: • Amino acid-modified graphene quantum dots (GQDs) were synthesized through acylation and amination reactions. • The presence of Fe{sup 3+} will cause obvious fluorescence quenching of the three kinds of GQDs. • A general sensing strategy for Fe{sup 3+} detection was successfully developed. • The proposed sensing strategy can successfully detect Fe{sup 3+} in real water sample. - Abstract: Amino acid-modified graphene quantum dots (GQDs) were synthesized through acylation and amination reactions. The as-synthesized GQDs were characterized by high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and UV–vis absorption and fluorescence spectroscopy. A general sensing strategy for detection of Fe{sup 3+} was successfully developed. The detection limit can reach as low as 50 nM. Moreover, the proposed sensing system was successfully employed to detect Fe{sup 3+} in real water sample, and satisfactory results were obtained. This work will open up new avenues to develop potential applications of GQDs materials in environmental monitoring.

  8. Compact binary coalescences in the band of ground-based gravitational-wave detectors

    International Nuclear Information System (INIS)

    Mandel, Ilya; O'Shaughnessy, Richard

    2010-01-01

    As the ground-based gravitational-wave telescopes LIGO, Virgo and GEO 600 approach the era of first detections, we review the current knowledge of the coalescence rates and the mass and spin distributions of merging neutron-star and black-hole binaries. We emphasize the bi-directional connection between gravitational-wave astronomy and conventional astrophysics. Astrophysical input will make possible informed decisions about optimal detector configurations and search techniques. Meanwhile, rate upper limits, detected merger rates and the distribution of masses and spins measured by gravitational-wave searches will constrain astrophysical parameters through comparisons with astrophysical models. Future developments necessary to the success of gravitational-wave astronomy are discussed.

  9. Status and plans for future generations of ground-based interferometric gravitational wave antennas

    International Nuclear Information System (INIS)

    Kawamura, Seiji

    2003-01-01

    Several medium- to large-scale ground-based interferometric gravitational-wave antennas have been constructed around the world. Although these antennas of the first generation could detect gravitational waves within a few years, it is necessary to improve the sensitivity of the detectors significantly with advanced technologies to ensure more frequent detection of gravitational waves. Stronger seismic isolation and reduction of thermal noise, especially using cryogenic mirrors, are among the most important technologies that can lead us to the realization of advanced detectors. Some of the advanced technologies are already implemented in some of the existing detectors and others are currently being investigated for the future-generation detectors such as advanced LIGO, LCGT, upgrade of GEO600, AIGO, and EURO. We expect that such advanced detectors will eventually open a new window to the universe and establish a new field, 'gravitational wave astronomy'

  10. A novel electrochemical sensing strategy for rapid and ultrasensitive detection of Salmonella by rolling circle amplification and DNA–AuNPs probe

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Dan; Yan, Yurong; Lei, Pinhua; Shen, Bo [Key Laboratory of Clinical Laboratory Diagnostics (Ministry of Education), College of Laboratory Medicine, Chongqing Medical University, Chongqing 400016 (China); Cheng, Wei [Key Laboratory of Clinical Laboratory Diagnostics (Ministry of Education), College of Laboratory Medicine, Chongqing Medical University, Chongqing 400016 (China); The Center for Clinical Molecular Medical detection, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016 (China); Ju, Huangxian [Key Laboratory of Clinical Laboratory Diagnostics (Ministry of Education), College of Laboratory Medicine, Chongqing Medical University, Chongqing 400016 (China); State Key Laboratory of Analytical Chemistry for Life Science, Department of Chemistry, Nanjing University, Nanjing 210093 (China); Ding, Shijia, E-mail: dingshijia@163.com [Key Laboratory of Clinical Laboratory Diagnostics (Ministry of Education), College of Laboratory Medicine, Chongqing Medical University, Chongqing 400016 (China)

    2014-10-10

    A novel electrochemical sensing strategy was developed for ultrasensitive and rapid detection of Salmonella by combining the rolling circle amplification with DNA–AuNPs probe. - Highlights: • This paper presented a novel sensing strategy for the rapid and ultrasensitive detection for Salmonella. • Combination of rolling circle amplification and DNA–AuNPs probe is the first time for Salmonella electrochemical detection. • The method displayed excellent sensitivity and specificity for detection of Salmonella. • The fabricated biosensor was successfully applied to detect Salmonella in milk samples. - Abstract: A novel electrochemical sensing strategy was developed for ultrasensitive and rapid detection of Salmonella by combining the rolling circle amplification with DNA–AuNPs probe. The target DNA could be specifically captured by probe 1 on the sensing interface. Then the circularization mixture was added to form a typical sandwich structure. In the presence of dNTPs and phi29 DNA polymerase, the RCA was initiated to produce micrometer-long single-strand DNA. Finally, the detection probe (DNA–AuNPs) could recognize RCA product to produce enzymatic electrochemical signal. Under optimal conditions, the calibration curve of synthetic target DNA had good linearity from 10 aM to 10 pM with a detection limit of 6.76 aM (S/N = 3). The developed method had been successfully applied to detect Salmonella as low as 6 CFU mL{sup −1} in real milk sample. This proposed strategy showed great potential for clinical diagnosis, food safety and environmental monitoring.

  11. A novel electrochemical sensing strategy for rapid and ultrasensitive detection of Salmonella by rolling circle amplification and DNA–AuNPs probe

    International Nuclear Information System (INIS)

    Zhu, Dan; Yan, Yurong; Lei, Pinhua; Shen, Bo; Cheng, Wei; Ju, Huangxian; Ding, Shijia

    2014-01-01

    A novel electrochemical sensing strategy was developed for ultrasensitive and rapid detection of Salmonella by combining the rolling circle amplification with DNA–AuNPs probe. - Highlights: • This paper presented a novel sensing strategy for the rapid and ultrasensitive detection for Salmonella. • Combination of rolling circle amplification and DNA–AuNPs probe is the first time for Salmonella electrochemical detection. • The method displayed excellent sensitivity and specificity for detection of Salmonella. • The fabricated biosensor was successfully applied to detect Salmonella in milk samples. - Abstract: A novel electrochemical sensing strategy was developed for ultrasensitive and rapid detection of Salmonella by combining the rolling circle amplification with DNA–AuNPs probe. The target DNA could be specifically captured by probe 1 on the sensing interface. Then the circularization mixture was added to form a typical sandwich structure. In the presence of dNTPs and phi29 DNA polymerase, the RCA was initiated to produce micrometer-long single-strand DNA. Finally, the detection probe (DNA–AuNPs) could recognize RCA product to produce enzymatic electrochemical signal. Under optimal conditions, the calibration curve of synthetic target DNA had good linearity from 10 aM to 10 pM with a detection limit of 6.76 aM (S/N = 3). The developed method had been successfully applied to detect Salmonella as low as 6 CFU mL −1 in real milk sample. This proposed strategy showed great potential for clinical diagnosis, food safety and environmental monitoring

  12. Exploration of strategies for implementation of screen-printed mercuric iodide converters in direct detection AMFPIs for digital breast tomosynthesis

    Science.gov (United States)

    Antonuk, Larry E.; El-Mohri, Youcef; Zhao, Qihua; Jiang, Hao

    2017-03-01

    Digital breast tomosynthesis (DBT) has become an increasingly important tool in the diagnosis of breast disease. For those DBT imaging systems based on active matrix, flat-panel imager (AMFPI) arrays, the incident radiation is detected directly or indirectly by means of an a-Se or CsI:Tl x-ray converter, respectively. While all AMFPI DBT devices provide clinically useful volumetric information, their performance is limited by the relatively modest average signal generated per interacting X ray by present converters compared to the electronic additive noise of the system. To address this constraint, we are pursuing the development of a screen-printed form of mercuric iodide (SP HgI2) which has demonstrated considerably higher sensitivities (i.e., larger average signal per interacting X ray) than those of conventional a-Se and CsI:Tl converters, as well as impressive DQE and MTF performance under mammographic irradiation conditions. A converter offering such enhanced sensitivity would greatly improve signal-to-noise performance and facilitate quantum-limited imaging down to significantly lower exposures than present AMFPI DBT systems. However, before this novel converter material can be implemented practically, challenges associated with SP HgI2 must be addressed. Most significantly, high levels of charge trapping (which lead to image lag as well as fall-off in DQE at higher exposures) need to be reduced - while improving the uniformity in pixel-to-pixel signal response as well as maintaining low dark current and otherwise favorable DQE performance. In this paper, a pair of novel strategies for overcoming the challenge of charge trapping in SP HgI2 converters are described, and initial results from empirical and calculational studies of these strategies are reported.

  13. Ground-based lidar remote sensing of contrails

    Energy Technology Data Exchange (ETDEWEB)

    Jaeger, H.; Freudenthaler, V.; Homburg, F.; Sussmann, R. [Fraunhofer-Institut fuer Atmosphaerische Umweltforschung (IFU), Garmisch-Partenkirchen (Germany)

    1997-12-01

    A ground-based scanning lidar system with built-in CCD camera has been developed to investigate aerosols and persistent contrails in air traffic corridors with respect to growth and microphysical and optical properties. By calibrating CCD camera images with lidar information the optical depth of larger areas of contrail cover within the 40 degree viewing angle of the camera can be determined. This technique has been extended to investigate contrails in AVHRR satellite images. (orig.) 144 figs., 42 tabs., 497 refs.

  14. A New Technique to Observe ENSO Activity via Ground-Based GPS Receivers

    Science.gov (United States)

    Suparta, Wayan; Iskandar, Ahmad; Singh, Mandeep Singh Jit

    In an attempt to study the effects of global climate change in the tropics for improving global climate model, this paper aims to detect the ENSO events, especially El Nino phase by using ground-based GPS receivers. Precipitable water vapor (PWV) obtained from the Global Positioning System (GPS) Meteorology measurements in line with the sea surface temperature anomaly (SSTa) are used to connect their response to El Niño activity. The data gathered from four selected stations over the Southeast Asia, namely PIMO (Philippines), KUAL (Malaysia), NTUS (Singapore) and BAKO (Indonesia) for the year of 2009/2010 were processed. A strong correlation was observed for PIMO station with a correlation coefficient of -0.90, significantly at the 99 % confidence level. In general, the relationship between GPS PWV and SSTa at all stations on a weekly basis showed with a negative correlation. The negative correlation indicates that during the El Niño event, the PWV variation was in decreased trend. Decreased trend of PWV value is caused by a dry season that affected the GPS signals in the ocean-atmospheric coupling. Based on these promising results, we can propose that the ground-based GPS receiver is capable used to monitor ENSO activity and this is a new prospective method that previously unexplored.

  15. Ground-based VHE γ ray astronomy with air Cherenkov imaging telescopes

    International Nuclear Information System (INIS)

    Mirzoyan, R.

    2000-01-01

    The history of astronomy has been one of the scientific discovery following immediately the introduction of new technology. In this report, we will review shortly the basic development of the atmospheric air Cherenkov light detection technique, particularly the imaging telescope technique, which in the last years led to the firm establishment of a new branch in experimental astronomy, namely ground-based very high-energy (VHE) γ ray astronomy. Milestones in the technology and in the analysis of imaging technique will be discussed. The design of the 17 m diameter MAGIC Telescope, being currently under construction, is based on the development of new technologies for all its major parts and sets new standards in the performance of the ground-based γ detectors. MAGIC is one of the next major steps in the development of the technique being the first instrument that will allow one to carry out measurements also in the not yet investigated energy gap i.e. between 10 and 300 GeV

  16. Clinical development of a failure detection-based online repositioning strategy for prostate IMRT--experiments, simulation, and dosimetry study.

    Science.gov (United States)

    Liu, Wu; Qian, Jianguo; Hancock, Steven L; Xing, Lei; Luxton, Gary

    2010-10-01

    To implement and evaluate clinic-ready adaptive imaging protocols for online patient repositioning (motion tracking) during prostate IMRT using treatment beam imaging supplemented by minimal, as-needed use of on-board kV. The authors examine the two-step decision-making strategy: (1) Use cine-MV imaging and online-updated characterization of prostate motion to detect target motion that is potentially beyond a predefined threshold and (2) use paired MV-kV 3D localization to determine overthreshold displacement and, if needed, reposition the patient. Two levels of clinical implementation were evaluated: (1) Field-by-field based motion correction for present-day linacs and (2) instantaneous repositioning for new-generation linacs with capabilities of simultaneous MV-kV imaging and remote automatic couch control during treatment delivery. Experiments were performed on a Varian Trilogy linac in clinical mode using a 4D motion phantom programed with prostate motion trajectories taken from patient data. Dosimetric impact was examined using a 2D ion chamber array. Simulations were done for 536 trajectories from 17 patients. Despite the loss of marker detection efficiency caused by the MLC leaves sometimes obscuring the field at the marker's projected position on the MV imager, the field-by-field correction halved (from 23% to 10%) the mean percentage of time that target displacement exceeded a 3 mm threshold, as compared to no intervention. This was achieved at minimal cost in additional imaging (average of one MV-kV pair per two to three treatment fractions) and with a very small number of repositionings (once every four to five fractions). Also with low kV usage (approximation 2/fraction), the instantaneous repositioning approach reduced overthreshold time by more than 75% (23% to 5%) even with severe MLC blockage as often encountered in current IMRT and could reduce the overthreshold time tenfold (to < 2%) if the MLC blockage problem were relieved. The information

  17. Clinical development of a failure detection-based online repositioning strategy for prostate IMRT--Experiments, simulation, and dosimetry study

    International Nuclear Information System (INIS)

    Liu Wu; Qian Jianguo; Hancock, Steven L.; Xing, Lei; Luxton, Gary

    2010-01-01

    Purpose: To implement and evaluate clinic-ready adaptive imaging protocols for online patient repositioning (motion tracking) during prostate IMRT using treatment beam imaging supplemented by minimal, as-needed use of on-board kV. Methods: The authors examine the two-step decision-making strategy: (1) Use cine-MV imaging and online-updated characterization of prostate motion to detect target motion that is potentially beyond a predefined threshold and (2) use paired MV-kV 3D localization to determine overthreshold displacement and, if needed, reposition the patient. Two levels of clinical implementation were evaluated: (1) Field-by-field based motion correction for present-day linacs and (2) instantaneous repositioning for new-generation linacs with capabilities of simultaneous MV-kV imaging and remote automatic couch control during treatment delivery. Experiments were performed on a Varian Trilogy linac in clinical mode using a 4D motion phantom programed with prostate motion trajectories taken from patient data. Dosimetric impact was examined using a 2D ion chamber array. Simulations were done for 536 trajectories from 17 patients. Results: Despite the loss of marker detection efficiency caused by the MLC leaves sometimes obscuring the field at the marker's projected position on the MV imager, the field-by-field correction halved (from 23% to 10%) the mean percentage of time that target displacement exceeded a 3 mm threshold, as compared to no intervention. This was achieved at minimal cost in additional imaging (average of one MV-kV pair per two to three treatment fractions) and with a very small number of repositionings (once every four to five fractions). Also with low kV usage (∼2/fraction), the instantaneous repositioning approach reduced overthreshold time by more than 75% (23% to 5%) even with severe MLC blockage as often encountered in current IMRT and could reduce the overthreshold time tenfold (to <2%) if the MLC blockage problem were relieved. The

  18. Cryptorchidism: strategies in detection

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, H.T.; Coakley, F.; Hricak, H. [Department of Radiology, Univ. of California, San Francisco (United States)

    1999-03-01

    Imaging evaluation of the patient with a non-palpable testis has evolved over recent decades. The rational explanation of imaging in these patients requires a clear understanding of the various causes of a non-palpable testis, and an appreciation of the utility and limitations of the available imaging modalities. This review describes the classification of non-palpable testis and discusses the role of modern imaging in evaluation. In particular, the relative accuracies of ultrasound, CT and MRI is reviewed. (orig.) With 9 figs., 37 refs.

  19. Strategy; Strategies

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2005-07-15

    Francois Loos, Minister of Industry, explains the French energy policy in the frame of Europe. ONERC is a French public body in charge of defining a national strategy against climate changes. It submits its first strategic elements to the Government. (authors)

  20. Ground-Based Lidar for Atmospheric Boundary Layer Ozone Measurements

    Science.gov (United States)

    Kuang, Shi; Newchurch, Michael J.; Burris, John; Liu, Xiong

    2013-01-01

    Ground-based lidars are suitable for long-term ozone monitoring as a complement to satellite and ozonesonde measurements. However, current ground-based lidars are unable to consistently measure ozone below 500 m above ground level (AGL) due to both engineering issues and high retrieval sensitivity to various measurement errors. In this paper, we present our instrument design, retrieval techniques, and preliminary results that focus on the high-temporal profiling of ozone within the atmospheric boundary layer (ABL) achieved by the addition of an inexpensive and compact mini-receiver to the previous system. For the first time, to the best of our knowledge, the lowest, consistently achievable observation height has been extended down to 125 m AGL for a ground-based ozone lidar system. Both the analysis and preliminary measurements demonstrate that this lidar measures ozone with a precision generally better than 10% at a temporal resolution of 10 min and a vertical resolution from 150 m at the bottom of the ABL to 550 m at the top. A measurement example from summertime shows that inhomogeneous ozone aloft was affected by both surface emissions and the evolution of ABL structures.

  1. Validation of Carbon Monoxide Total Column Retrievals from SCIAMACHY Observations with NDACC/TCCON Ground-Based Measurements

    Directory of Open Access Journals (Sweden)

    Philipp Hochstaffl

    2018-02-01

    Full Text Available The objective was to validate the carbon monoxide (CO total column product inferred from Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY full-mission (2003–2011 short-wave infrared (SWIR nadir observations using the Beer InfraRed Retrieval Algorithm (BIRRA. Globally distributed Network for the Detection of Atmospheric Composition Change (NDACC and Total Carbon Column Observing Network (TCCON ground-based (g-b measurements were used as a true reference. Weighted averages of SCIAMACHY CO observations within a circle around the g-b observing system were utilized to minimize effects due to spatial mismatch of space-based (s-b and g-b observations, i.e., disagreements due to representation errors rather than instrument and/or algorithm deficiencies. In addition, temporal weighted averages were examined and then the unweighted (classical approach was compared to the weighted (non-classical method. The delivered distance-based filtered SCIAMACHY data were in better agreement with respect to CO averages as compared to square-shaped sampling areas throughout the year. Errors in individual SCIAMACHY retrievals have increased substantially since 2005. The global bias was determined to be in the order of − 10 parts per billion in volume (ppbv depending on the reference network and validation strategy used. The largest negative bias was found to occur in the northern mid-latitudes in Europe and North America, and was partly caused by insufficient a priori estimates of CO and cloud shielding. Furthermore, no significant trend was identified in the global bias throughout the mission. The global analysis of the CO columns retrieved by the BIRRA shows results that are largely consistent with similar investigations in previous works.

  2. A Rapid Label-Free Fluorescent Aptasensor PicoGreen-Based Strategy for Aflatoxin B₁ Detection in Traditional Chinese Medicines.

    Science.gov (United States)

    Zhang, Cheng; Dou, Xiaowen; Zhang, Lei; Sun, Meifeng; Zhao, Ming; OuYang, Zhen; Kong, Dandan; Antonio, F Logrieco; Yang, Meihua

    2018-02-28

    Aflatoxin B₁ (AFB₁) is a very hazardous carcinogen, readily contaminating foodstuffs and traditional Chinese medicines (TCMs) that has inspired increasing health concerns due to dietary exposure. Colloidal nanocrystals have been proposed as optical labels for aptasensor assembly, but these typically require tedious multistep conjugation and suffer from unsatisfactory robustness when used for complex matrices. In the present study, we report a rapid and sensitive method for screening for trace AFB₁ levels in TCMs using a label-free fluorescent aptasensor PicoGreen dye-based strategy. Using PicoGreen to selectively measure complementary double-stranded DNA, fluorescence enhancement due to dsDNA is 'turned off' in the presence of AFB₁ due binding of aptamer target over complementary sequence. Self-assembly of a label-free fluorescent aptasensor based on AFB₁ aptamer and PicoGreen dye was performed. Due to competition between the complementary sequence and AFB₁ target, this rapid method was capable of highly sensitive and selective screening for AFB₁ in five types of TCMs. This proposed approach had a limit of detection as low as 0.1 μg·L -1 and good linearity with a range of 0.1-10 μg·L -1 (0.1-10 ppb). Among the 20 samples tested, 6 batches were found to be contaminated with AFB₁ using this method, which was confirmed using sophisticated liquid chromatography-electrospray ionization-tandem mass spectrometry/mass spectrometry analysis. The results of this study indicate the developed method has the potential to be a simple, quick, and sensitive tool for detecting AFB₁ in TCMs.

  3. A real-time PCR-based strategy for the detection of Paenibacillus larvae vegetative cells and spores to improve the diagnosis and the screening of American foulbrood.

    Science.gov (United States)

    Martínez, J; Simon, V; Gonzalez, B; Conget, P

    2010-06-01

    To develop a real-time PCR-based strategy for the detection of Paenibacillus larvae vegetative cells and spores to improve the diagnosis and the screening of American foulbrood (AFB), the most harmful pathology of honeybee brood. A real-time PCR that allowed selective identification and quantification of P. larvae 16S rRNA sequence was developed. Using standard samples quantified by flow cytometry, detection limits of 37.5 vegetative cells ml(-1) and 10 spores ml(-1) were determined. Compared to spread plate method, this real-time PCR-based strategy allowed, in only 2 h, the detection of P. larvae in contaminated honeys. No false-positive results were obtained. Moreover, its detection limit was 100 times lower than that of the culture method (2 vs 200 spores g(-1) of honey). A rapid, selective, with low detection limit, sensitive and specific method to detect and quantify vegetative cells and spores of P. larvae is now available. In addition to honey samples, this real-time PCR-based strategy may be also applied to confirm AFB diagnosis in honeybee brood and to screen other apiary supplies and products (bees, pollen, wax), thus broadening the control of AFB spreading.

  4. Disulfide-induced self-assembled targets : A novel strategy for the label free colorimetric detection of DNAs/RNAs via unmodified gold nanoparticles

    NARCIS (Netherlands)

    Shokri, Ehsan; Hosseini, Morteza; Davari, Mehdi D.; Ganjali, Mohammad R.; Peppelenbosch, Maikel P.; Rezaee, Farhad

    2017-01-01

    A modified non-cross-linking gold-nanoparticles (Au-NPs) aggregation strategy has been developed for the label free colorimetric detection of DNAs/RNAs based on self-assembling target species in the presence of thiolated probes. Two complementary thiol-modified probes, each of which specifically

  5. Disulfide-induced self-assembled targets: A novel strategy for the label free colorimetric detection of DNAs/RNAs via unmodified gold nanoparticles

    NARCIS (Netherlands)

    Shokri, E. (Ehsan); M. Hosseini (Morteza); Davari, M.D. (Mehdi D.); Ganjali, M.R. (Mohammad R.); M.P. Peppelenbosch (Maikel); F. Rezaee (Farhad)

    2017-01-01

    textabstractA modified non-cross-linking gold-nanoparticles (Au-NPs) aggregation strategy has been developed for the label free colorimetric detection of DNAs/RNAs based on self-assembling target species in the presence of thiolated probes. Two complementary thiol- modified probes, each of which

  6. Copper ion-induced fluorescence band shift of CdTe quantum dots: a highly specific strategy for visual detection of Cu(2+) with a portable UV lamp.

    Science.gov (United States)

    Lu, Xiaohui; Zhao, Yunjie; Zhang, Jinjun; Lu, Xiaozhen; Wang, Yucong; Liu, Chenghui

    2015-12-07

    We have developed a new colorimetric strategy that allows visual detection of Cu(2+) under the irradiation of a UV lamp with high specificity based on the phenomenon that copper ions may lead to a fluorescence band shift of CdTe quantum dots (QDs) while other concomitant ions will not.

  7. Multiband Gravitational-Wave Astronomy: Parameter Estimation and Tests of General Relativity with Space- and Ground-Based Detectors.

    Science.gov (United States)

    Vitale, Salvatore

    2016-07-29

    With the discovery of the binary-black-hole (BBH) coalescence GW150914 the era of gravitational-wave (GW) astronomy has started. It has recently been shown that BBH with masses comparable to or higher than GW150914 would be visible in the Evolved Laser Interferometer Space Antenna (eLISA) band a few years before they finally merge in the band of ground-based detectors. This would allow for premerger electromagnetic alerts, dramatically increasing the chances of a joint detection, if BBHs are indeed luminous in the electromagnetic band. In this Letter we explore a quite different aspect of multiband GW astronomy, and verify if, and to what extent, measurement of masses and sky position with eLISA could improve parameter estimation and tests of general relativity with ground-based detectors. We generate a catalog of 200 BBHs and find that having prior information from eLISA can reduce the uncertainty in the measurement of source distance and primary black hole spin by up to factor of 2 in ground-based GW detectors. The component masses estimate from eLISA will not be refined by the ground based detectors, whereas joint analysis will yield precise characterization of the newly formed black hole and improve consistency tests of general relativity.

  8. Biosensors for EVA: Improved Instrumentation for Ground-based Studies

    Science.gov (United States)

    Soller, B.; Ellerby, G.; Zou, F.; Scott, P.; Jin, C.; Lee, S. M. C.; Coates, J.

    2010-01-01

    During lunar excursions in the EVA suit, real-time measurement of metabolic rate is required to manage consumables and guide activities to ensure safe return to the base. Metabolic rate, or oxygen consumption (VO2), is normally measured from pulmonary parameters but cannot be determined with standard techniques in the oxygen-rich environment of a spacesuit. Our group has developed novel near infrared spectroscopic (NIRS) methods to calculate muscle oxygen saturation (SmO 2), hematocrit, and pH, and we recently demonstrated that we can use our NIRS sensor to measure VO 2 on the leg during cycling. Our NSBRI project has 4 objectives: (1) increase the accuracy of the metabolic rate calculation through improved prediction of stroke volume; (2) investigate the relative contributions of calf and thigh oxygen consumption to metabolic rate calculation for walking and running; (3) demonstrate that the NIRS-based noninvasive metabolic rate methodology is sensitive enough to detect decrement in VO 2 in a space analog; and (4) improve instrumentation to allow testing within a spacesuit. Over the past year we have made progress on all four objectives, but the most significant progress was made in improving the instrumentation. The NIRS system currently in use at JSC is based on fiber optics technology. Optical fiber bundles are used to deliver light from a light source in the monitor to the patient, and light reflected back from the patient s muscle to the monitor for spectroscopic analysis. The fiber optic cables are large and fragile, and there is no way to get them in and out of the test spacesuit used for ground-based studies. With complimentary funding from the US Army, we undertook a complete redesign of the sensor and control electronics to build a novel system small enough to be used within the spacesuit and portable enough to be used by a combat medic. In the new system the filament lamp used in the fiber optic system was replaced with a novel broadband near infrared

  9. Dual Recognition Strategy for Specific and Sensitive Detection of Bacteria Using Aptamer-Coated Magnetic Beads and Antibiotic-Capped Gold Nanoclusters.

    Science.gov (United States)

    Cheng, Dan; Yu, Mengqun; Fu, Fei; Han, Weiye; Li, Gan; Xie, Jianping; Song, Yang; Swihart, Mark T; Song, Erqun

    2016-01-05

    Food poisoning and infectious diseases caused by pathogenic bacteria such as Staphylococcus aureus (SA) are serious public health concerns. A method of specific, sensitive, and rapid detection of such bacteria is essential and important. This study presents a strategy that combines aptamer and antibiotic-based dual recognition units with magnetic enrichment and fluorescent detection to achieve specific and sensitive quantification of SA in authentic specimens and in the presence of much higher concentrations of other bacteria. Aptamer-coated magnetic beads (Apt-MB) were employed for specific capture of SA. Vancomycin-stabilized fluorescent gold nanoclusters (AuNCs@Van) were prepared by a simple one-step process and used for sensitive quantification of SA in the range of 32-10(8) cfu/mL with the detection limit of 16 cfu/mL via a fluorescence intensity measurement. And using this strategy, about 70 cfu/mL of SA in complex samples (containing 3 × 10(8) cfu/mL of other different contaminated bacteria) could be successfully detected. In comparison to prior studies, the developed strategy here not only simplifies the preparation procedure of the fluorescent probes (AuNCs@Van) to a great extent but also could sensitively quantify SA in the presence of much higher concentrations of other bacteria directly with good accuracy. Moreover, the aptamer and antibiotic used in this strategy are much less expensive and widely available compared to common-used antibodies, making it cost-effective. This general aptamer- and antibiotic-based dual recognition strategy, combined with magnetic enrichment and fluorescent detection of trace bacteria, shows great potential application in monitoring bacterial food contamination and infectious diseases.

  10. Use of mass spectrometry methods as a strategy for detection and determination of residual solvents in pharmaceutical products.

    Science.gov (United States)

    Pérez Pavón, José Luis; del Nogal Sanchez, Miguel; García Pinto, Carmelo; Fernandez Laespada, M Esther; Moreno Cordero, Bernardo

    2006-07-15

    In the present work a strategy for the qualitative and quantitative analysis of residual solvents in pharmaceutical products is reported. First, a low-resolution chromatogram is generated for the identification of the solvents present in the samples by means of headspace generation-fast gas chromatography-mass spectrometry (HS-fast GC/MS). From the plotting of this information by means of contour plots with time and mass/charge axes, it is decided whether quantification of such compounds can be accomplished without chromatographic separation or whether it should be done by fast gas chromatography. The nonseparative method is based on direct coupling of a headspace sampler with a mass spectrometer (HS-MS) and requires a signal recording time of only 3 min, while with fast gas chromatography the time required to obtain a chromatogram is 7.16 min. The use of headspace generation for introducing the sample and standard addition as a quantification technique provided satisfactory results and minimized the matrix effect. An important advantage of the methodologies used here is related to the fact that no prior treatment of the sample is required, thus minimizing the creation of analytical artifacts and the errors associated with this step of the analytical process. The methods were applied to the determination of residual solvents in 27 different pharmaceutical products. Detection and quantitation limits were sufficiently low to enable the estimation of organic volatile impurities according to the International Conference on Harmonization (ICH) of Technical Requirements for the Registration of Pharmaceuticals for Human Use.

  11. Strategy and its implications of protein bioanalysis utilizing high-resolution mass spectrometric detection of intact protein.

    Science.gov (United States)

    Ruan, Qian; Ji, Qin C; Arnold, Mark E; Humphreys, W Griffith; Zhu, Mingshe

    2011-12-01

    Currently, mass spectrometry-based protein bioanalysis is primarily achieved through monitoring the representative peptide(s) resulting from analyte protein digestion. However, this approach is often incapable of differentiating the measurement of protein analyte from its post-translational modifications (PTMs) and/or potential biotransformation (BTX) products. This disadvantage can be overcome by direct measurement of the intact protein analytes. Selected reaction monitoring (SRM) on triple quadrupole mass spectrometers has been used for the direct measurement of intact protein. However, the fragmentation efficiency though the SRM process could be limited in many cases, especially for high molecular weight proteins. In this study, we present a new strategy of intact protein bioanalysis by high-resolution (HR) full scan mass spectrometry using human lysozyme as a model protein. An HR linear ion-trap/Orbitrap mass spectrometer was used for detection. A composite of isotopic peaks from one or multiple charge states can be isolated from the background and used to improve the signal-to-noise ratio. The acquired data were processed by summing extracted ion chromatograms (EIC) of the 10 most intense isotopic ions of octuply protonated lysozyme. Quantitation of the plasma lysozyme was conducted by utilizing high resolving power and an EIC window fitting to the protein molecular weight. An assay with a linear dynamic range from 0.5 to 500 μg/mL was developed with good accuracy and precision. The assay was successfully employed for monitoring the level of endogenous lysozyme and a potential PTM in human plasma. The current instrumentation limitations and potential advantages of this approach for the bioanalysis of large proteins are discussed.

  12. Magnetospheric Perturbations Related to IMF Discontinuity Passing Through the Magnetosheath: THEMIS and Ground-Based Observations

    Science.gov (United States)

    Dmitriev, A. V.; Suvorova, A. V.

    2010-12-01

    We present a case event of THEMIS and ground-based observations of the magnetopause and geomagnetic field perturbations related to passing a discontinuity of interplanetary magnetic field (IMF) through the magnetosheath. As observed by the ACE upstream monitor, the IMF discontinuity is rotational, i.e. it is characterized by sudden change of the IMF orientation without any changes in solar wind plasma characteristics. The normal to IMF rotation plane is inclined duskward and northward. During passing through the magnetosheath the discontinuity is not rotational any more: THEMIS detects substantial depletion of the magnetosheath at the leading edge of discontinuity and very strong compression at the trailing edge, where the total magnetosheath pressure is revealed to be 3 times higher than the upstream solar wind dynamic pressure. The magnetosheath compression is contributed by enhanced thermal ion and magnetic pressures. This spatial heterogeneity in the magnetosheath pressure causes a local distortion of the Chapman-Ferraro current (CFR) and, hence, transient outward and inward magnetopause motion, respectively, with amplitude more than 1.5 Re. The transient motion results in a local significant distortion of the magnetopause shape that is revealed as a substantial deviation of the magnetopause normal from its nominal direction. Inside the magnetosphere, the CFR distortion is detected by THEMIS as a bipolar magnetic impulse with very high amplitude of ~40 nT. The INTERMAGNET network of ground-based magnetometers allows tracing the movement of the CFR distortion related to the discontinuity propagation through the magnetosheath. We find that the bipolar impulse in horizontal component of geomagnetic field propagates from south to north and from dawn to dusk that is in good agreement with the IMF discontinuity orientation observed by ACE.

  13. Independent Component Analysis applied to Ground-based observations

    Science.gov (United States)

    Martins-Filho, Walter; Griffith, Caitlin; Pearson, Kyle; Waldmann, Ingo; Alvarez-Candal, Alvaro; Zellem, Robert Thomas

    2018-01-01

    Transit measurements of Jovian-sized exoplanetary atmospheres allow one to study the composition of exoplanets, largely independent of the planet’s temperature profile. However, measurements of hot-Jupiter transits must archive a level of accuracy in the flux to determine the spectral modulation of the exoplanetary atmosphere. To accomplish this level of precision, we need to extract systematic errors, and, for ground-based measurements, the effects of Earth’s atmosphere, from signal due to the exoplanet, which is several orders of magnitude smaller. The effects of the terrestrial atmosphere and some of the time-dependent systematic errors of ground-based transit measurements are treated mainly by dividing the host star by a reference star at each wavelength and time step of the transit. Recently, Independent Component Analysis (ICA) have been used to remove systematics effects from the raw data of space-based observations (Waldmann, 2014, 2012; Morello et al., 2016, 2015). ICA is a statistical method born from the ideas of the blind-source separations studies, which can be used to de-trend several independent source signals of a data set (Hyvarinen and Oja, 2000). This technique requires no additional prior knowledge of the data set. In addition, this technique has the advantage of requiring no reference star. Here we apply the ICA to ground-based photometry of the exoplanet XO-2b recorded by the 61” Kuiper Telescope and compare the results of the ICA to those of a previous analysis from Zellem et al. (2015), which does not use ICA. We also simulate the effects of various conditions (concerning the systematic errors, noise and the stability of object on the detector) to determine the conditions under which an ICA can be used with high precision to extract the light curve of exoplanetary photometry measurements

  14. Comparison of monthly nighttime cloud fraction products from MODIS and AIRS and ground-based camera over Manila Observatory (14.64N, 121.07E)

    Science.gov (United States)

    Gacal, G. F. B.; Lagrosas, N.

    2017-12-01

    Cloud detection nowadays is primarily achieved by the utilization of various sensors aboard satellites. These include MODIS Aqua, MODIS Terra, and AIRS with products that include nighttime cloud fraction. Ground-based instruments are, however, only secondary to these satellites when it comes to cloud detection. Nonetheless, these ground-based instruments (e.g., LIDARs, ceilometers, and sky-cameras) offer significant datasets about a particular region's cloud cover values. For nighttime operations of cloud detection instruments, satellite-based instruments are more reliably and prominently used than ground-based ones. Therefore if a ground-based instrument for nighttime operations is operated, it ought to produce reliable scientific datasets. The objective of this study is to do a comparison between the results of a nighttime ground-based instrument (sky-camera) and that of MODIS Aqua and MODIS Terra. A Canon Powershot A2300 is placed ontop of Manila Observatory (14.64N, 121.07E) and is configured to take images of the night sky at 5min intervals. To detect pixels with clouds, the pictures are converted to grayscale format. Thresholding technique is used to screen pixels with cloud and pixels without clouds. If the pixel value is greater than 17, it is considered as a cloud; otherwise, a noncloud (Gacal et al., 2016). This algorithm is applied to the data gathered from Oct 2015 to Oct 2016. A scatter plot between satellite cloud fraction in the area covering the area 14.2877N, 120.9869E, 14.7711N and 121.4539E and ground cloud cover is graphed to find the monthly correlation. During wet season (June - November), the satellite nighttime cloud fraction vs ground measured cloud cover produce an acceptable R2 (Aqua= 0.74, Terra= 0.71, AIRS= 0.76). However, during dry season, poor R2 values are obtained (AIRS= 0.39, Aqua & Terra = 0.01). The high correlation during wet season can be attributed to a high probability that the camera and satellite see the same clouds

  15. Lidar to lidar calibration of Ground-based Lidar

    DEFF Research Database (Denmark)

    Fernandez Garcia, Sergio; Courtney, Michael

    This report presents the result of the lidar to lidar calibration performed for ground-based lidar. Calibration is here understood as the establishment of a relation between the reference lidar wind speed measurements with measurement uncertainties provided by measurement standard and corresponding...... lidar wind speed indications with associated measurement uncertainties. The lidar calibration concerns the 10 minute mean wind speed measurements. The comparison of the lidar measurements of the wind direction with that from the reference lidar measurements are given for information only....

  16. A novel integrated strategy for detection of human bocavirus based on a heminested PCR assay combined with boiling lysis method of samples in human specimens.

    Science.gov (United States)

    Chen, Long; Yao, Qing; Ma, Jing; Li, Jianning; Zhang, Qian; Yang, Yi; Li, Fang; Sun, Yuning

    2014-07-01

    Human bocavirus (HBoV) has been shown to be associated with acute respiratory tract infection in children. The aim of the work was to develop a novel integrated strategy for human bocavirus detection: heminested PCR assay combined with boiling lysis method of samples. The detection limit of the heminested PCR assay was 1.2 copies of a recombinant DNA plasmid, and no cross-reaction with other respiratory viruses or bacteria was observed. By using the integrated strategy, a total of 202 secretions of the lower respiratory tract of children with acute respiratory diseases were collected and tested. The samples were treated and lysed in boiling lysis buffer rather than extracting viral DNA from secretions, then these sample lysates could be templates and tested by heminested PCR assay, and the amplification of HBoV DNA was detected by using agarose gel electrophoresis. The results showed that, only 7 samples were found to be positive by conventional single-round PCR; importantly, the other new 41 samples were positive by heminested PCR assay. Additionally, the genomic viral DNA was extracted from all positive and some negative specimens, amplified, and sequenced. The results were perfectly consistent with those of the integrated strategy. Taken together, these results suggest that the novel integrated strategy (heminested PCR assay combined with boiling lysis method of samples) is a convenient, sensitive, cost-effective and reliable detective method for HBoV detection and will have broad application prospects in clinical diagnosis. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Development of a stochastic agent-based model to evaluate surveillance strategies for detection of emergent porcine reproductive and respiratory syndrome strains.

    Science.gov (United States)

    Arruda, A G; Poljak, Z; Knowles, D; McLean, A

    2017-06-12

    The objective of the current study was to develop a stochastic agent-based model using empirical data from Ontario (Canada) swine sites in order to evaluate different surveillance strategies for detection of emerging porcine reproductive and respiratory syndrome virus (PRRSV) strains at the regional level. Four strategies were evaluated, including (i) random sampling of fixed numbers of swine sites monthly; (ii) risk-based sampling of fixed numbers, specifically of breeding sites (high-consequence sites); (iii) risk-based sampling of fixed numbers of low biosecurity sites (high-risk); and (iv) risk-based sampling of breeding sites that are characterized as low biosecurity sites (high-risk/high-consequence). The model simulated transmission of a hypothetical emerging PRRSV strain between swine sites through three important industry networks (production system, truck and feed networks) while considering sites' underlying immunity due to past or recent exposure to heterologous PRRSV strains, as well as demographic, geographic and biosecurity-related PRRS risk factors. Outcomes of interest included surveillance system sensitivity and time to detection of the three first cases over a period of approximately three years. Surveillance system sensitivities were low and time to detection of three first cases was long across all examined scenarios. Traditional modes of implementing high-risk and high-consequence risk-based surveillance based on site's static characteristics do not appear to substantially improve surveillance system sensitivity. Novel strategies need to be developed and considered for rapid detection of this and other emerging swine infectious diseases. None of the four strategies compared herein appeared optimal for early detection of an emerging PPRSV strain at the regional level considering model assumptions, the underlying population of interest, and absence of other forms of surveillance.

  18. Evaluating Ground-based Proxies for Solar Irradiance Variation

    Science.gov (United States)

    Oegerle, William (Technical Monitor); Jordan, Stuart

    2003-01-01

    In order to determine what ground-based proxies are best for evaluating solar irradiance variation before the advent of space observations, it is necessary to test these proxies against space observations. We have tested sunspot number, total sunspot area, and sunspot umbral area against the Nimbus-7 measurements of total solar irradiance variation cover the eleven year period 1980-1990. The umbral area yields the best correlation and the total sunspot area yields the poorest. Reasons for expecting the umbral area to yield the best correlation are given, the statistical procedure followed to obtain the results is described, and the value of determining the best proxy is discussed. The latter is based upon the availability of an excellent database from the Greenwich Observatory obtained over the period 1876-1976, which can be used to estimate the total solar irradiance variation before sensitive space observations were available. The ground-based observations used were obtained at the Coimbra Solar Observatory. The analysis was done at Goddard using these data and data from the Nimbus-7 satellite.

  19. SAFARI 2000 AERONET Ground-based Aerosol Data, Dry Season 2000

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: AERONET (AErosol RObotic NETwork) is an optical ground-based aerosol monitoring network and data archive system. AERONET measurements of the...

  20. Laser Guidestar Satellite for Ground-based Adaptive Optics Imaging of Geosynchronous Satellites and Astronomical Targets

    Science.gov (United States)

    Marlow, W. A.; Cahoy, K.; Males, J.; Carlton, A.; Yoon, H.

    2015-12-01

    Real-time observation and monitoring of geostationary (GEO) satellites with ground-based imaging systems would be an attractive alternative to fielding high cost, long lead, space-based imagers, but ground-based observations are inherently limited by atmospheric turbulence. Adaptive optics (AO) systems are used to help ground telescopes achieve diffraction-limited seeing. AO systems have historically relied on the use of bright natural guide stars or laser guide stars projected on a layer of the upper atmosphere by ground laser systems. There are several challenges with this approach such as the sidereal motion of GEO objects relative to natural guide stars and limitations of ground-based laser guide stars; they cannot be used to correct tip-tilt, they are not point sources, and have finite angular sizes when detected at the receiver. There is a difference between the wavefront error measured using the guide star compared with the target due to cone effect, which also makes it difficult to use a distributed aperture system with a larger baseline to improve resolution. Inspired by previous concepts proposed by A.H. Greenaway, we present using a space-based laser guide starprojected from a satellite orbiting the Earth. We show that a nanosatellite-based guide star system meets the needs for imaging GEO objects using a low power laser even from 36,000 km altitude. Satellite guide star (SGS) systemswould be well above atmospheric turbulence and could provide a small angular size reference source. CubeSatsoffer inexpensive, frequent access to space at a fraction of the cost of traditional systems, and are now being deployed to geostationary orbits and on interplanetary trajectories. The fundamental CubeSat bus unit of 10 cm cubed can be combined in multiple units and offers a common form factor allowing for easy integration as secondary payloads on traditional launches and rapid testing of new technologies on-orbit. We describe a 6U CubeSat SGS measuring 10 cm x 20 cm x

  1. 5'/ 3' imbalance strategy to detect ALK fusion genes in circulating tumor RNA from patients with non-small cell lung cancer.

    Science.gov (United States)

    Tong, Yongqing; Zhao, Zhijun; Liu, Bei; Bao, Anyu; Zheng, Hongyun; Gu, Jian; McGrath, Mary; Xia, Ying; Tan, Bihua; Song, Chunhua; Li, Yan

    2018-03-27

    Detecting an ALK fusion gene in patients with non-small cell lung cancer (NSCLC) could provide evidence to guide individualized therapy. The 5'/3' imbalance strategy for quantitative reverse transcription-PCR (RT-qPCR) was developed to detect ALK fusion genes in circulating tumor RNA (ctRNA) of NSCLC patients. This method was validated in patients with the ALK fusion gene confirmed by next generation sequencing (NGS). The amount of the ALK fusion gene detected by the new method ranged from 33.2 to 987.4, (mean 315.2), in the patients confirmed to have the ALK fusion gene (+). This is much higher than the amount of fusion gene detected in the patients who are negative for the ALK fusion gene (-). The amount detected in the ALK fusion gene (-) samples ranged from 0.36 to 13.04, (mean 4.58). In 188 NSCLC patients, the specificity and sensitivity of the method was compared to that of the FISH method. About 10.64% of the patients showed higher ALK fusion gene expression, and were classified as ALK fusion gene (+). This is identical to the percentage of patients detected by the FISH method to be ALK fusion gene (+). The cutoff value for diagnosis of ALK fusion (+) is 32.9 as determined by this method. A new RT-PCR method using a 5'/3' imbalance strategy was developed, with high specificity and sensitivity, for detection of the ALK fusion gene in ctRNA of NSCLC patients. This method can rapidly detect ALK fusion genes in patients, which will be helpful for guiding targeted therapy, particularly the individualized usage of TKIs in these patients.

  2. Comparing Aerosol Retrievals from Ground-Based Instruments at the Impact-Pm Field Campaign

    Science.gov (United States)

    Kupinski, M.; Bradley, C. L.; Kalashnikova, O. V.; Xu, F.; Diner, D. J.; Clements, C. B.; Camacho, C.

    2016-12-01

    Detection of aerosol types, components having different size and chemical composition, over urban areas is important for understanding their impact on health and climate. In particular, sustained contact with size-differentiated airborne particulate matter: PM10 and PM2.5 can lead to adverse health effects such as asthma attacks, heart and lung diseases, and premature mortality. Multi-angular polarimetric measurements have been advocated in recent years as an additional tool to better understand and retrieve the aerosol properties needed for improved predictions of aerosol impart on air quality and climate. We deployed the ground-based Multiangle SpectroPolarimetric Imager (GroundMSPI) for accurate spectropolarimetric and radiance measurements co-located with the AERONET CIMEL sun photometer and a Halo Doppler 18 m resolution lidar from San José State University at the Garland-Fresno Air Quality supersite in Fresno, CA on July 7 during the Imaging Polarimetric Assessment and Characterization of Tropospheric Particulate Matter (ImPACT-PM) field experiment. GroundMSPI sampled the atmospheric scattering phase function in and 90 degrees out of the principal plane every 15 minutes in an automated manner, utilizing the 2-axis gimbal mount in elevation and azimuth. The goal of this work is verify atmospheric measurement of GroundMSPI with the coincident CIMEL sun photometer and ground-based lidar. Diffuse-sky radiance measurements of GroundMSPI are compared with the CIMEL sun photometer throughout the day. AERONET aerosol parameters such as size, shape, and index of refraction as well as lidar aerosol extinction profiles will be used in a forward radiative transfer model to compare with GroundMSPI observations and optimize these parameters to best match GroundMSPI data.

  3. GROMOS-C, a novel ground-based microwave radiometer for ozone measurement campaigns

    Science.gov (United States)

    Fernandez, S.; Murk, A.; Kämpfer, N.

    2015-07-01

    Stratospheric ozone is of major interest as it absorbs most harmful UV radiation from the sun, allowing life on Earth. Ground-based microwave remote sensing is the only method that allows for the measurement of ozone profiles up to the mesopause, over 24 hours and under different weather conditions with high time resolution. In this paper a novel ground-based microwave radiometer is presented. It is called GROMOS-C (GRound based Ozone MOnitoring System for Campaigns), and it has been designed to measure the vertical profile of ozone distribution in the middle atmosphere by observing ozone emission spectra at a frequency of 110.836 GHz. The instrument is designed in a compact way which makes it transportable and suitable for outdoor use in campaigns, an advantageous feature that is lacking in present day ozone radiometers. It is operated through remote control. GROMOS-C is a total power radiometer which uses a pre-amplified heterodyne receiver, and a digital fast Fourier transform spectrometer for the spectral analysis. Among its main new features, the incorporation of different calibration loads stands out; this includes a noise diode and a new type of blackbody target specifically designed for this instrument, based on Peltier elements. The calibration scheme does not depend on the use of liquid nitrogen; therefore GROMOS-C can be operated at remote places with no maintenance requirements. In addition, the instrument can be switched in frequency to observe the CO line at 115 GHz. A description of the main characteristics of GROMOS-C is included in this paper, as well as the results of a first campaign at the High Altitude Research Station at Jungfraujoch (HFSJ), Switzerland. The validation is performed by comparison of the retrieved profiles against equivalent profiles from MLS (Microwave Limb Sounding) satellite data, ECMWF (European Centre for Medium-Range Weather Forecast) model data, as well as our nearby NDACC (Network for the Detection of Atmospheric

  4. Universal quantum dot-based sandwich-like immunoassay strategy for rapid and ultrasensitive detection of small molecules using portable and reusable optofluidic nano-biosensing platform

    International Nuclear Information System (INIS)

    Zhou, Liping; Zhu, Anna; Lou, Xuening; Song, Dan; Yang, Rong; Shi, Hanchang; Long, Feng

    2016-01-01

    A universal sandwich-like immunoassay strategy based on quantum-dots immunoprobe (QD-labeled anti-mouse IgG antibody) was developed for rapid and ultrasensitive detection of small molecules. A portable and reusable optofluidic nano-biosensing platform was applied to investigate the sandwich-like immunoassay mechanism and format of small molecules, as well as the binding kinetics between QD immunoprobe and anti-small molecule antibody. A two-step immunoassay method that involves pre-incubation mixture of different concentration of small molecule and anti-small molecule antibody, and subsequent introduction of QD immunoprobe into the optofluidic cell was conducted for small molecule determination. Compared with the one-step immunoassay method, the two-step immunoassay method can obtain higher fluorescence signal and higher sensitivity index, thus improving the nano-biosensing performance. Based on the proposed strategy, two mode targets, namely, microcystin-LR (MC-LR) and Bisphenol A (BPA) were tested with high sensitivity, rapidity, and ease of use. A higher concentration of small molecules in the sample led to less anti-small molecule antibody bound with antigen-carrier protein conjugate immobilized onto the sensor surface, and less QD immunoprobes bound with anti-small molecule antibody. This phenomenon lowered the fluorescence signal detected by nano-biosensing platform. Under optimal operating conditions, MC-LR and BPA exhibited a limit of detection of 0.003 and 0.04 μg/L, respectively. The LODs were better than those of the indirect competitive immunoassay method for small molecules via Cy5.5-labeled anti-small molecule antibody. The proposed QD-based sandwich-like immunoassay strategy was evaluated in spiked water samples, and showed good recovery, precision and accuracy without complicated sample pretreatments. All these results demonstrate that the new detection strategy could be readily applied to the other trace small molecules in real water samples

  5. Universal quantum dot-based sandwich-like immunoassay strategy for rapid and ultrasensitive detection of small molecules using portable and reusable optofluidic nano-biosensing platform

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Liping; Zhu, Anna; Lou, Xuening; Song, Dan; Yang, Rong [School of Environment and Natural Resources, Renmin University of China, Beijing (China); Shi, Hanchang [School of Environment, Tsinghua University, Beijing (China); Long, Feng, E-mail: longf04@ruc.edu.cn [School of Environment and Natural Resources, Renmin University of China, Beijing (China)

    2016-01-28

    A universal sandwich-like immunoassay strategy based on quantum-dots immunoprobe (QD-labeled anti-mouse IgG antibody) was developed for rapid and ultrasensitive detection of small molecules. A portable and reusable optofluidic nano-biosensing platform was applied to investigate the sandwich-like immunoassay mechanism and format of small molecules, as well as the binding kinetics between QD immunoprobe and anti-small molecule antibody. A two-step immunoassay method that involves pre-incubation mixture of different concentration of small molecule and anti-small molecule antibody, and subsequent introduction of QD immunoprobe into the optofluidic cell was conducted for small molecule determination. Compared with the one-step immunoassay method, the two-step immunoassay method can obtain higher fluorescence signal and higher sensitivity index, thus improving the nano-biosensing performance. Based on the proposed strategy, two mode targets, namely, microcystin-LR (MC-LR) and Bisphenol A (BPA) were tested with high sensitivity, rapidity, and ease of use. A higher concentration of small molecules in the sample led to less anti-small molecule antibody bound with antigen-carrier protein conjugate immobilized onto the sensor surface, and less QD immunoprobes bound with anti-small molecule antibody. This phenomenon lowered the fluorescence signal detected by nano-biosensing platform. Under optimal operating conditions, MC-LR and BPA exhibited a limit of detection of 0.003 and 0.04 μg/L, respectively. The LODs were better than those of the indirect competitive immunoassay method for small molecules via Cy5.5-labeled anti-small molecule antibody. The proposed QD-based sandwich-like immunoassay strategy was evaluated in spiked water samples, and showed good recovery, precision and accuracy without complicated sample pretreatments. All these results demonstrate that the new detection strategy could be readily applied to the other trace small molecules in real water samples

  6. 3D Modeling of Landslide in Open-pit Mining on Basis of Ground-based LIDAR Data

    Science.gov (United States)

    Hu, H.; Fernandez-Steeger, T. M.; Azzam, R.; Arnhardt, C.

    2009-04-01

    Slope stability is not only an important problem which is related to production and safety in open-pit mining, but also very complex task. There are three main reasons which affect the slope stability as follows: geotechnical factors: Geological structure, lithologic characteristics, water, cohesion, friction, etc.; climate factors: Rainfall and temperature; and external factors: Open-pit mining process, explosion vibration, dynamic load, etc.. The 3rd reason, as a specially one in open-pit mining, not only causes some dynamic problems but also induces the fast geometry changing which must be considered in the following research using numerical simulation and stability analysis. Recently, LIDAR technology has been applied in many fields and places in the world wide. Ground-based LIDAR technology with high accuracy up to 3mm increasingly accommodates to monitoring landslides and detecting changing. LIDAR data collection and preprocessing research have been carried out by Department of Engineering Geology and Hydrogeology at RWTH Aachen University. LIDAR data, so-called a point-cloud of mass data in high density can be obtained in short time for the sensitive open-pit mining area by using ground-based LIDAR. To obtain a consistent surface model, it is necessary to set up multiple scans with the ground-based LIDAR. The framework of data preprocessing which can be implemented by Poly-Works is introduced as follows: gross error detection and elimination, integration of reference frame, model fusion of different scans (re-sampled in overlap region), data reduction without removing the useful information which is a challenge and research front in LIDAR data processing. After data preprocessing, 3D surface model can be directly generated in Poly-Works or generated in other software by building the triangular meshes. The 3D surface landslide model can be applied to further researches such as: real time landslide geometry monitoring due to the fast data collection and

  7. Comparing the outcomes of two strategies for colorectal tumor detection: Policy-promoted screening program versus health promotion service

    Directory of Open Access Journals (Sweden)

    Ping-Hsiu Wu

    2013-06-01

    Conclusion: In comparison with the outcomes of the HPS database, the screening efficacy of the PPS database is even for detecting colorectal carcinoma but is limited in detecting advanced adenoma. HPS may provide comprehensive validity indicators and will be helpful in adjusting current policies for improving screening performance.

  8. RECONSTRUCTION OF SKY ILLUMINATION DOMES FROM GROUND-BASED PANORAMAS

    Directory of Open Access Journals (Sweden)

    F. Coubard

    2012-07-01

    Full Text Available The knowledge of the sky illumination is important for radiometric corrections and for computer graphics applications such as relighting or augmented reality. We propose an approach to compute environment maps, representing the sky radiance, from a set of ground-based images acquired by a panoramic acquisition system, for instance a mobile-mapping system. These images can be affected by important radiometric artifacts, such as bloom or overexposure. A Perez radiance model is estimated with the blue sky pixels of the images, and used to compute additive corrections in order to reduce these radiometric artifacts. The sky pixels are then aggregated in an environment map, which still suffers from discontinuities on stitching edges. The influence of the quality of estimated sky radiance on the simulated light signal is measured quantitatively on a simple synthetic urban scene; in our case, the maximal error for the total sensor radiance is about 10%.

  9. Factors influencing detection of the federally endangered Diamond Darter Crystallaria cincotta: Implications for long-term monitoring strategies

    Science.gov (United States)

    Rizzo, Austin A.; Brown, Donald J.; Welsh, Stuart A.; Thompson, Patricia A.

    2017-01-01

    Population monitoring is an essential component of endangered species recovery programs. The federally endangered Diamond Darter Crystallaria cincotta is in need of an effective monitoring design to improve our understanding of its distribution and track population trends. Because of their small size, cryptic coloration, and nocturnal behavior, along with limitations associated with current sampling methods, individuals are difficult to detect at known occupied sites. Therefore, research is needed to determine if survey efforts can be improved by increasing probability of individual detection. The primary objective of this study was to determine if there are seasonal and diel patterns in Diamond Darter detectability during population surveys. In addition to temporal factors, we also assessed five habitat variables that might influence individual detection. We used N-mixture models to estimate site abundances and relationships between covariates and individual detectability and ranked models using Akaike's information criteria. During 2015 three known occupied sites were sampled 15 times each between May and Oct. The best supported model included water temperature as a quadratic function influencing individual detectability, with temperatures around 22 C resulting in the highest detection probability. Detection probability when surveying at the optimal temperature was approximately 6% and 7.5% greater than when surveying at 16 C and 29 C, respectively. Time of Night and day of year were not strong predictors of Diamond Darter detectability. The results of this study will allow researchers and agencies to maximize detection probability when surveying populations, resulting in greater monitoring efficiency and likely more precise abundance estimates.

  10. Rapid detection of acute myocardial infarction-related miRNA based on a Capture-interCalation-electroCatalysis (3C) strategy.

    Science.gov (United States)

    Chen, Guifang; Shen, Yalan; Xu, Tianzhao; Ban, Fangfang; Yin, Li; Xiao, Junjie; Shu, Yongqian

    2016-03-15

    Acute myocardial infarction (AMI) is one of the most urgent and serious diseases that may cause cardiac death in a few hours. Rapid diagnosis of AMI is the pre-requisite for timely interventions. Recently, several specific circulating miRNAs have been proven to have high correlation with AMI. To adopt miRNA as a biomarker may improve the diagnostic accuracy. However, it is a pity that the current available methods for the detection of miRNA usually require a few hours, which is too long for the diagnosis of AMI. In this paper, by adopting a capture DNA, an electrochemical active intercalator and an unimmobilized enzyme, we develop a Capture-interCalation-electroCatalysis (3C) strategy for the rapid detection of AMI-related miRNA. The whole detection process can be completed in 35 min, which is much shorter than most current methods and is acceptable for the diagnosis of AMI. This strategy also shows favorable sensitivity and selectivity, thus provides an alternative for the detection of miRNA. Most importantly, this effort may promote miRNA to work as an effective biomarker in the diagnosis of AMI. Copyright © 2015. Published by Elsevier B.V.

  11. Defining a strategy to evaluate cervical cancer prevention and early detection in the era of HPV vaccination.

    Science.gov (United States)

    Howlett, Roberta I; Miller, Anthony B; Pasut, George; Mai, Verna

    2009-05-01

    The purpose of this paper is to outline the short-, medium- and long-term requirements of a strategy to evaluate the impact of HPV immunization and to define a framework to facilitate planning and evaluation. This strategy was developed in Ontario from January to August 2008. Literature review was completed to assess existing material relevant to vaccine evaluation, and HPV vaccine specifically. Scientists and epidemiologists within our organization attended meetings to brainstorm and identify key requirements for vaccine evaluation. Other selected internal and external experts were consulted to review preliminary lists of potential indicators and questions for inclusion in an evaluation strategy. Results are reported in three sections--literature review, proposed evaluation framework and data requirements. The first vaccine evaluation strategy that integrates primary and secondary prevention of cervical cancer is presented. Among women who are neither screened nor immunized, customized interventions will be required to ensure that they are aware of potential risks and benefits. This evaluation strategy may serve as a useful outline for jurisdictions in Canada and elsewhere. This new paradigm of combined primary and secondary intervention will encourage cooperation for effective evaluation of an integrated approach for control of cervical cancer and other HPV-related disease.

  12. A beveled working electrode coupled to a sandglass shape detection cell: A strategy to improve the sensitivity of electrochemiluminescence detection in microchip electrophoresis

    International Nuclear Information System (INIS)

    Pan, Jianbin; Li, Xinchun; Chen, Zuanguang; Yang, Fan; Wu, Xiaohang; Li, Yinbao; Sun, Duanping; Yu, Yanyan

    2013-01-01

    A beveled working electrode (WE) with a sandglass shape electrochemiluminescence (ECL) detection cell based on tris(2,2′-bipyridyl)ruthenium(II) (TBR) for microchip capillary electrophoresis (MCE) was described in this paper. The beveled WE was readily fabricated from a platinum (Pt) wire (0.3 mm diameter). The microchip comprised of three layers: top polydimethylsiloxane (PDMS) layer, middle glass plate, and bottom glass coverslip. The middle layer was a glass wafer on which the injection and separation channels were etched; meanwhile, an inverted funnel hole was made by a coniform drill, and a snot which was used to hold a guide tube aligning to the separation channel outlet was fabricated by a clubbed drill. The top layer was PDMS block containing four holes that connected injection channels and separation channel terminals, respectively. The two layers were bonded after their surfaces were processed by a plasma cleaner. The bottom layer was a coverslip (0.17 mm thick) which covered the inverted funnel hole in the middle layer with epoxy resin. The beveled WE was inserted into the guide tube and immobilized using melt adhesive. A Pt wire acted as a counter electrode (CE) was penetrated through the PDMS layer perpendicularly to the WE, with a 1.5-mm long portion left inside the detection cell. Proline was used to evaluate the developed MCE–ECL microdevice with the limit of detection down to 0.2 μM (S/N = 3). The detection sensitivity was found to be improved remarkably, compared to the conventional disk electrode

  13. Are French Dyslexic Children Sensitive to Consonant Sonority in Segmentation Strategies? Preliminary Evidence from a Letter Detection Task

    Science.gov (United States)

    Maionchi-Pino, Norbert; de Cara, Bruno; Ecalle, Jean; Magnan, Annie

    2012-01-01

    This paper aims to investigate whether--and how--consonant sonority (obstruent vs. sonorant) and status (coda vs. onset) within syllable boundaries modulate the syllable-based segmentation strategies. Here, it is questioned whether French dyslexic children, who experience acoustic-phonetic (i.e., voicing) and phonological impairments, are…

  14. A ground-based near-infrared emission spectrum of the exoplanet HD 189733b.

    Science.gov (United States)

    Swain, Mark R; Deroo, Pieter; Griffith, Caitlin A; Tinetti, Giovanna; Thatte, Azam; Vasisht, Gautam; Chen, Pin; Bouwman, Jeroen; Crossfield, Ian J; Angerhausen, Daniel; Afonso, Cristina; Henning, Thomas

    2010-02-04

    Detection of molecules using infrared spectroscopy probes the conditions and compositions of exoplanet atmospheres. Water (H(2)O), methane (CH(4)), carbon dioxide (CO(2)), and carbon monoxide (CO) have been detected in two hot Jupiters. These previous results relied on space-based telescopes that do not provide spectroscopic capability in the 2.4-5.2 microm spectral region. Here we report ground-based observations of the dayside emission spectrum for HD 189733b between 2.0-2.4 microm and 3.1-4.1 microm, where we find a bright emission feature. Where overlap with space-based instruments exists, our results are in excellent agreement with previous measurements. A feature at approximately 3.25 microm is unexpected and difficult to explain with models that assume local thermodynamic equilibrium (LTE) conditions at the 1 bar to 1 x 10(-6) bar pressures typically sampled by infrared measurements. The most likely explanation for this feature is that it arises from non-LTE emission from CH(4), similar to what is seen in the atmospheres of planets in our own Solar System. These results suggest that non-LTE effects may need to be considered when interpreting measurements of strongly irradiated exoplanets.

  15. Proceedings of the 2009 Monitoring Research Review: Ground-Based Nuclear Explosion Monitoring Technologies

    Energy Technology Data Exchange (ETDEWEB)

    Wetovsky, Marv A [Los Alamos National Laboratory; Aguilar - Chang, Julio [Los Alamos National Laboratory; Anderson, Dale [Los Alamos National Laboratory; Arrowsmith, Marie [Los Alamos National Laboratory; Arrowsmith, Stephen [Los Alamos National Laboratory; Baker, Diane [Los Alamos National Laboratory; Begnaud, Michael [Los Alamos National Laboratory; Harste, Hans [Los Alamos National Laboratory; Maceira, Monica [Los Alamos National Laboratory; Patton, Howard [Los Alamos National Laboratory; Phillips, Scott [Los Alamos National Laboratory; Randall, George [Los Alamos National Laboratory; Rowe, Charlotte [Los Alamos National Laboratory; Stead, Richard [Los Alamos National Laboratory; Steck, Lee [Los Alamos National Laboratory; Whitaker, Rod [Los Alamos National Laboratory; Yang, Xiaoning ( David ) [Los Alamos National Laboratory

    2009-09-21

    These proceedings contain papers prepared for the Monitoring Research Review 2009: Ground -Based Nuclear Explosion Monitoring Technologies, held 21-23 September, 2009 in Tucson, Arizona,. These papers represent the combined research related to ground-based nuclear explosion monitoring funded by the National Nuclear Security Administration (NNSA), Air Force Research Laboratory (AFRL), US Army Space and Missile Defense Command, Comprehensive Test Ban Treaty Organization (CTBTO), and other invited sponsors. The scientific objectives of the research are to improve the United States’ capability to detect, locate, and identify nuclear explosions. The purpose of the meeting is to provide the sponsoring agencies, as well as potential users, an opportunity to review research accomplished during the preceding year and to discuss areas of investigation for the coming year. For the researchers, it provides a forum for the exchange of scientific information toward achieving program goals, and an opportunity to discuss results and future plans. Paper topics include: seismic regionalization and calibration; detection and location of sources; wave propagation from source to receiver; the nature of seismic sources, including mining practices; hydroacoustic, infrasound, and radionuclide methods; on-site inspection; and data processing.

  16. Novel strategy for sulfapyridine detection using a fully integrated electrochemical Bio-MEMS: Application to honey analysis.

    Science.gov (United States)

    Hassani, Nadia El Alami El; Baraket, Abdoullatif; Neto, Ernandes Taveira Tenório; Lee, Michael; Salvador, J-Pablo; Marco, M-Pilar; Bausells, Joan; Bari, Nezha El; Bouchikhi, Benachir; Elaissari, Abdelhamid; Errachid, Abdelhamid; Zine, Nadia

    2017-07-15

    Sulfapyridine (SPy) is a sulfonamide antibiotic largely employed as veterinary drugs for prophylactic and therapeutic purposes. Therefore, its spread in the food products has to be restricted. Herein, we report the synthesis and characterization of a novel electrochemical biosensor based on gold microelectrodes modified with a new structure of magnetic nanoparticles (MNPs) coated with poly(pyrrole-co-pyrrole-2-carboxylic acid) (Py/Py-COOH) for high efficient detection of SPy. This analyte was quantified through a competitive detection procedure with 5-[4-(amino)phenylsulfonamide]-5-oxopentanoic acid-BSA (SA2-BSA) antigens toward polyclonal antibody (Ab-155). Initially, gold working electrodes (WEs) of integrated biomicro electro-mechanical system (BioMEMS) were functionalized by Ppy-COOH/MNPs, using a chronoamperometric (CA) electrodeposition. Afterward, SA2-BSA was covalently bonded to Py/Py-COOH/MNP modified gold WEs through amide bonding. The competitive detection of the analyte was made by a mixture of a fixed concentration of Ab-155 and decreasing concentrations of SPy from 50µgL -1 to 2ngL -1 . Atomic Force Microscopy characterization was performed in order to ensure Ppy-COOH/MNPs electrodeposition on the microelectrode surfaces. Electrochemical measurements of SPy detection were carried out using electrochemical impedance spectroscopy (EIS). This biosensor was found to be highly sensitive and specific for SPy, with a limit of detection of 0.4ngL -1 . This technique was exploited to detect SPy in honey samples by using the standard addition method. The measurements were highly reproducible for detection and interferences namely, sulfadiazine (SDz), sulfathiazole (STz) and sulfamerazine (SMz). Taking these advantages of sensitivity, specificity, and low cost, our system provides a new horizon for development of advanced immunoassays in industrial food control. Copyright © 2016. Published by Elsevier B.V.

  17. A targeted door-to-door strategy for sleeping sickness detection in low-prevalence settings in Côte d’Ivoire

    Directory of Open Access Journals (Sweden)

    Koffi Mathurin

    2016-01-01

    Full Text Available Significant efforts to control human African trypanosomiasis (HAT over the three past decades have resulted in drastic reductions of disease prevalence in Côte d’Ivoire. In this context, the costly and labor-intensive active mass screening strategy is no longer efficient. In addition to a more cost-effective passive surveillance system being implemented in this low-prevalence context, our aim was to develop an alternative targeted active screening strategy. In 2012, we carried out a targeted door-to-door (TDD survey focused on the immediate vicinities of former HAT patients detected in the HAT focus of Bonon and compared the results to those obtained during classical active mass screening (AMS surveys conducted from 2000 to 2012 in the same area. The TDD that provides a friendlier environment, inviting inhabitants to participate and gain awareness of the disease, detected significantly more HAT cases than the AMS. These results suggest that the TDD is an efficient and useful strategy in low-prevalence settings where very localized transmission cycles may persist and, in combination with passive surveillance, could help in eliminating HAT.

  18. Validation of ACE and OSIRIS ozone and NO2 measurements using ground-based instruments at 80° N

    Directory of Open Access Journals (Sweden)

    A. Pazmino

    2012-05-01

    Full Text Available The Optical Spectrograph and Infra-Red Imager System (OSIRIS and the Atmospheric Chemistry Experiment (ACE have been taking measurements from space since 2001 and 2003, respectively. This paper presents intercomparisons between ozone and NO2 measured by the ACE and OSIRIS satellite instruments and by ground-based instruments at the Polar Environment Atmospheric Research Laboratory (PEARL, which is located at Eureka, Canada (80° N, 86° W and is operated by the Canadian Network for the Detection of Atmospheric Change (CANDAC. The ground-based instruments included in this study are four zenith-sky differential optical absorption spectroscopy (DOAS instruments, one Bruker Fourier transform infrared spectrometer (FTIR and four Brewer spectrophotometers. Ozone total columns measured by the DOAS instruments were retrieved using new Network for the Detection of Atmospheric Composition Change (NDACC guidelines and agree to within 3.2%. The DOAS ozone columns agree with the Brewer spectrophotometers with mean relative differences that are smaller than 1.5%. This suggests that for these instruments the new NDACC data guidelines were successful in producing a homogenous and accurate ozone dataset at 80° N. Satellite 14–52 km ozone and 17–40 km NO2 partial columns within 500 km of PEARL were calculated for ACE-FTS Version 2.2 (v2.2 plus updates, ACE-FTS v3.0, ACE-MAESTRO (Measurements of Aerosol Extinction in the Stratosphere and Troposphere Retrieved by Occultation v1.2 and OSIRIS SaskMART v5.0x ozone and Optimal Estimation v3.0 NO2 data products. The new ACE-FTS v3.0 and the validated ACE-FTS v2.2 partial columns are nearly identical, with mean relative differences of 0.0 ± 0.2% and −0.2 ± 0.1% for v2.2 minus v3.0 ozone and NO2, respectively. Ozone columns were constructed from 14–52 km satellite and 0–14 km ozonesonde partial columns and compared with the ground-based total column measurements. The satellite-plus-sonde measurements agree

  19. Multifactor dimensionality reduction: An analysis strategy for modelling and detecting gene - gene interactions in human genetics and pharmacogenomics studies

    Directory of Open Access Journals (Sweden)

    Motsinger Alison A

    2006-03-01

    Full Text Available Abstract The detection of gene - gene and gene - environment interactions associated with complex human disease or pharmacogenomic endpoints is a difficult challenge for human geneticists. Unlike rare, Mendelian diseases that are associated with a single gene, most common diseases are caused by the non-linear interaction of numerous genetic and environmental variables. The dimensionality involved in the evaluation of combinations of many such variables quickly diminishes the usefulness of traditional, parametric statistical methods. Multifactor dimensionality reduction (MDR is a novel and powerful statistical tool for detecting and modelling epistasis. MDR is a non-parametric and model-free approach that has been shown to have reasonable power to detect epistasis in both theoretical and empirical studies. MDR has detected interactions in diseases such as sporadic breast cancer, multiple sclerosis and essential hypertension. As this method is more frequently applied, and was gained acceptance in the study of human disease and pharmacogenomics, it is becoming increasingly important that the implementation of the MDR approach is properly understood. As with all statistical methods, MDR is only powerful and useful when implemented correctly. Concerns regarding dataset structure, configuration parameters and the proper execution of permutation testing in reference to a particular dataset and configuration are essential to the method's effectiveness. The detection, characterisation and interpretation of gene - gene and gene - environment interactions are expected to improve the diagnosis, prevention and treatment of common human diseases. MDR can be a powerful tool in reaching these goals when used appropriately.

  20. Multifactor dimensionality reduction: An analysis strategy for modelling and detecting gene - gene interactions in human genetics and pharmacogenomics studies

    Science.gov (United States)

    2006-01-01

    The detection of gene - gene and gene - environment interactions associated with complex human disease or pharmacogenomic endpoints is a difficult challenge for human geneticists. Unlike rare, Mendelian diseases that are associated with a single gene, most common diseases are caused by the non-linear interaction of numerous genetic and environmental variables. The dimensionality involved in the evaluation of combinations of many such variables quickly diminishes the usefulness of traditional, parametric statistical methods. Multifactor dimensionality reduction (MDR) is a novel and powerful statistical tool for detecting and modelling epistasis. MDR is a non-parametric and model-free approach that has been shown to have reasonable power to detect epistasis in both theoretical and empirical studies. MDR has detected interactions in diseases such as sporadic breast cancer, multiple sclerosis and essential hypertension. As this method is more frequently applied, and was gained acceptance in the study of human disease and pharmacogenomics, it is becoming increasingly important that the implementation of the MDR approach is properly understood. As with all statistical methods, MDR is only powerful and useful when implemented correctly. Concerns regarding dataset structure, configuration parameters and the proper execution of permutation testing in reference to a particular dataset and configuration are essential to the method's effectiveness. The detection, characterisation and interpretation of gene - gene and gene - environment interactions are expected to improve the diagnosis, prevention and treatment of common human diseases. MDR can be a powerful tool in reaching these goals when used appropriately. PMID:16595076

  1. Multifactor dimensionality reduction: an analysis strategy for modelling and detecting gene-gene interactions in human genetics and pharmacogenomics studies.

    Science.gov (United States)

    Motsinger, Alison A; Ritchie, Marylyn D

    2006-03-01

    The detection of gene-gene and gene-environment interactions associated with complex human disease or pharmacogenomic endpoints is a difficult challenge for human geneticists. Unlike rare, Mendelian diseases that are associated with a single gene, most common diseases are caused by the non-linear interaction of numerous genetic and environmental variables. The dimensionality involved in the evaluation of combinations of many such variables quickly diminishes the usefulness of traditional, parametric statistical methods. Multifactor dimensionality reduction (MDR) is a novel and powerful statistical tool for detecting and modelling epistasis. MDR is a non-parametric and model-free approach that has been shown to have reasonable power to detect epistasis in both theoretical and empirical studies. MDR has detected interactions in diseases such as sporadic breast cancer, multiple sclerosis and essential hypertension. As this method is more frequently applied, and was gained acceptance in the study of human disease and pharmacogenomics, it is becoming increasingly important that the implementation of the MDR approach is properly understood. As with all statistical methods, MDR is only powerful and useful when implemented correctly. Concerns regarding dataset structure, configuration parameters and the proper execution of permutation testing in reference to a particular dataset and configuration are essential to the method's effectiveness. The detection, characterisation and interpretation of gene-gene and gene-environment interactions are expected to improve the diagnosis, prevention and treatment of common human diseases. MDR can be a powerful tool in reaching these goals when used appropriately.

  2. Power to detect higher-order epistatic interactions in a metabolic pathway using a new mapping strategy.

    Science.gov (United States)

    Stich, Benjamin; Yu, Jianming; Melchinger, Albrecht E; Piepho, Hans-Peter; Utz, H Friedrich; Maurer, Hans P; Buckler, Edward S

    2007-05-01

    Epistatic interactions among quantitative trait loci (QTL) contribute substantially to the variation in complex traits. The main objectives of this study were to (i) compare three- vs. four-step genome scans to identify three-way epistatic interactions among QTL belonging to a metabolic pathway, (ii) investigate by computer simulations the power and proportion of false positives (PFP) for detecting three-way interactions among QTL in recombinant inbred line (RIL) populations derived from a nested mating design, and (iii) compare these estimates to those obtained for detecting three-way interactions among QTL in RIL populations derived from diallel and different partial diallel mating designs. The single-nucleotide polymorphism haplotype data of B73 and 25 diverse maize inbreds were used to simulate the production of various RIL populations. Compared to the three-step genome scan, the power to detect three-way interactions was higher with the four-step genome scan. Higher power to detect three-way interactions was observed for RILs derived from optimally allocated distance-based designs than from nested designs or diallel designs. The power and PFP to detect three-way interactions using a nested design with 5000 RILs were for both the 4-QTL and the 12-QTL scenario of a magnitude that seems promising for their identification.

  3. A general fluorescent sensor design strategy for "turn-on" activity detection of exonucleases and restriction endonucleases based on graphene oxide.

    Science.gov (United States)

    Zhang, Qi; Kong, De-Ming

    2013-11-07

    Using graphene oxide (GO) as a nanoquencher, a universal sensor design strategy was developed on the basis of significantly different binding affinities of GO to single-stranded DNAs (ss-DNAs) with different lengths. The proposed sensors could be used for the activity detection of both exonucleases and restriction endonucleases. To achieve this, a single-labeled fluorescent oligonucleotide probe, which had a single-stranded structure or a hairpin structure with a long single-stranded loop, was used. Such a probe could be efficiently absorbed on the surface of GO, resulting in the quenching of the fluorescent signal. Excision of the single-stranded probe by exonucleases or site-specific cleavage at the double-stranded stem of the hairpin probe by restriction endonuclease released fluorophore-labeled nucleotide, which could not be efficiently absorbed by GO, thus leading to increase in fluorescence of the corresponding sensing system. As examples, three sensors, which were used for activity detection of the exonuclease Exo 1 and the restriction endonucleases EcoR I and Hind III, were developed. These three sensors could specifically and sensitively detect the activities of Exo 1, EcoR I and Hind III with detection limits of 0.03 U mL(-1), 0.06 U mL(-1) and 0.04 U mL(-1), respectively. Visual detection was also possible.

  4. [Multiplex PCR strategy for the simultaneous identification of Staphylococcus aureus and detection of staphylococcal enterotoxins in isolates from food poisoning outbreaks].

    Science.gov (United States)

    Brizzio, Aníbal A; Tedeschi, Fabián A; Zalazar, Fabián E

    2013-01-01

    Staphylococcal food poisoning is the most frequent type of food poisoning around the world. Staphylococcus aureus enterotoxins cause significant loss of water in the intestinal lumen, followed by vomiting and diarrhea. To report a fast, reliable and inexpensive strategy based on multiplex PCR for the simultaneous identification of S. aureus and detection of five classical S. aureus enterotoxin genes ( sea, seb, sec, sed, see ) in Staphylococcus spp. strains isolated from food poisoning outbreaks. We analyzed isolates from 12 food poisoning outbreaks occurred in Santa Fe province (Argentina). Isolation and phenotypic characterization were carried out by standard procedures. Genotypic analysis was performed by multiplex PCR, using primers for nuc , sea-see and 16S rRNA genes simultaneously. Of all the strains tested, 58% were found to carry toxigenic genes. Sea and seb toxins were found at the same percentage (29%) while sec, sed and see genes were found in a lower and identical proportion (14%). We did not find more than one different type of S. aureus enterotoxin in the isolates analyzed. The multiplex PCR strategy designed in this work has enabled us to identify strains of S. aureus and detect -at the same time- their enterotoxigenic ability. At present, our efforts are devoted to the detection of genes encoding enterotoxins other than the classical ones, in order to know their impact on staphylococcal food poisoning, as well as to investigate their relevance to our country's public health.

  5. Tropospheric BrO column densities in the Arctic derived from satellite: retrieval and comparison to ground-based measurements

    Directory of Open Access Journals (Sweden)

    H. Sihler

    2012-11-01

    Full Text Available During polar spring, halogen radicals like bromine monoxide (BrO play an important role in the chemistry of tropospheric ozone destruction. Satellite measurements of the BrO distribution have become a particularly useful tool to investigate this probably natural phenomenon, but the separation of stratospheric and tropospheric partial columns of BrO is challenging. In this study, an algorithm was developed to retrieve tropospheric vertical column densities of BrO from data of high-resolution spectroscopic satellite instruments such as the second Global Ozone Monitoring Experiment (GOME-2. Unlike recently published approaches, the presented algorithm is capable of separating the fraction of BrO in the activated troposphere from the total BrO column solely based on remotely measured properties. The presented algorithm furthermore allows to estimate a realistic measurement error of the tropospheric BrO column. The sensitivity of each satellite pixel to BrO in the boundary layer is quantified using the measured UV radiance and the column density of the oxygen collision complex O4. A comparison of the sensitivities with CALIPSO LIDAR observations demonstrates that clouds shielding near-surface trace-gas columns can be reliably detected even over ice and snow. Retrieved tropospheric BrO columns are then compared to ground-based BrO measurements from two Arctic field campaigns in the Amundsen Gulf and at Barrow in 2008 and 2009, respectively. Our algorithm was found to be capable of retrieving enhanced near-surface BrO during both campaigns in good agreement with ground-based data. Some differences between ground-based and satellite measurements observed at Barrow can be explained by both elevated and shallow surface layers of BrO. The observations strongly suggest that surface release processes are the dominating source of BrO and that boundary layer meteorology influences the vertical distribution.

  6. Elution strategies for reversed-phase high-performance liquid chromatography analysis of sucrose alkanoate regioisomers with charged aerosol detection

    DEFF Research Database (Denmark)

    Lie, Aleksander; Pedersen, Lars Haastrup

    2013-01-01

    A broad range of elution strategies for RP-HPLC analysis of sucrose alkanoate regioisomers with CAD was systematically evaluated. The HPLC analyses were investigated using design-of-experiments methodology and analysed by analysis of variance (ANOVA) and regression modelling. Isocratic elutions, ......L/min reduced RDm by 29% and analysis time by 6%, compared to isocratic elution at 38% acetonitrile with standard flow (1.0 mL/min)....

  7. Detection of successional stages and spatial patterns of forest initiation strategies for an abandoned tropical dry forest pasture in Guanacaste Costa Rica

    Science.gov (United States)

    Castillo-Nunez, Mauricio

    Canopy heights derived from a Waveform LIDAR sensor (LVIS) are used to identify characteristics of successional stages in an abandoned pasture in Guanacaste, Costa Rica. LIDAR canopy heights were validated through comparison with field collected heights The location of 3 classes derived from an automatic classification of the LIDAR data was compared against the location of successional stages identified a previous research. In addition the spatial location of two forest initiation strategies (seed dispersion) was investigated analyzing the textural information from a DEM (Digital Elevation Model) generated from the LVIS total canopy height data. The results of this research suggest a good agreement between successional stages reported in the literature and those identified with the LIDAR data. Also the fragments initiated by wind and vertebrate dispersion strategies detected in this study suggest a good agreement with several characteristics (spatial patterns) of such fragments reported by the literature.

  8. Boundary Detection and Enhancement Strategy for Power System Bus Bar Stabilization—Investigation under Fault Conditions for Islanding Operation

    Directory of Open Access Journals (Sweden)

    Aref Pouryekta

    2018-04-01

    Full Text Available Distribution systems can form islands when faults occur. Each island represents a subsection with variable boundaries subject to the location of fault(s in the system. A subsection with variable boundaries is referred to as an island in this paper. For operation in autonomous mode, it is imperative to detect the island configurations and stabilize these subsections. This paper presents a novel scheme for the detection of island boundaries and stabilizing the system during autonomous operation. In the first stage, a boundary detection method is proposed to detect the configuration of the island. In the second stage, a dynamic voltage sensitivity factor (DVSF is proposed to assess the dynamic performance of the system. In the third stage, a wide area load shedding program is adopted based on DVSF to shed the load in weak bus-bars and stabilize the system. The proposed scheme is validated and tested on a generic 18-bus system using a combination of EMTDC/PSCAD and MATLAB software’s.

  9. A novel strategy for human papillomavirus detection and genotyping with SybrGreen and molecular beacon polymerase chain reaction

    NARCIS (Netherlands)

    Szuhai, K; Sandhaus, E; Kolkman-Uljee, SM; Lemaitre, M; Truffert, JC; Dirks, RW; Tanke, HJ; Fleuren, GJ; Schuuring, E; Raap, AK

    2001-01-01

    Human papillomaviruses (HPVs) play an important role in the pathogenesis of cervical cancer. For identification of the large number of different HPV types found in (pre)malignant lesions, a robust methodology is needed that combines general HPV detection with HPV genotyping. We have developed for

  10. Electrochemical DNA probe for Hg(2+) detection based on a triple-helix DNA and Multistage Signal Amplification Strategy.

    Science.gov (United States)

    Wang, Huan; Zhang, Yihe; Ma, Hongmin; Ren, Xiang; Wang, Yaoguang; Zhang, Yong; Wei, Qin

    2016-12-15

    In this work, an ultrasensitive electrochemical sensor was developed for detection of Hg(2+). Gold nanoparticles decorated bovine serum albumin reduction of graphene oxide (AuNP-BSA-rGO) were used as subsurface material for the immobilization of triple-helix DNA. The triple-helix DNA containing a thiol labelled single-stranded DNA (sDNA) and a thymine-rich DNA (T-rich DNA), which could be unwinded in the present of Hg(2+) to form more stable thymine-Hg(2+)-thymine (T-Hg(2+)-T) complex. T-Hg(2+)-T complex was then removed and the sDNA was left on the electrode. At this time, gold nanoparticle carrying thiol labelled cytosine-rich complementary DNA (cDNA-AuNP) could bind with the free sDNA. Meanwhile, the other free cDNA on AuNP could bind with each other in the present of Ag(+) to form the stable cytosine-Ag(+)-cytosine (C-Ag(+)-C) complex and circle amplification. Plenty of C-Ag(+)-C could form silver nanoclusters by electrochemical reduction and the striping signal of Ag could be measured for purpose of the final electrochemical detection of Hg(2+). This sensor could detect Hg(2+) over a wide concentration range from 0.1 to 130nM with a detection limit of 0.03nM. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Detection of several common adulterants in raw milk by MID-infrared spectroscopy and one-class and multi-class multivariate strategies

    OpenAIRE

    RUISANCHEZ CAPELASTEGUI, MARÍA ICIAR; Gondim, C.D.S.; Junqueira, R.G.; Souza, S.V.C.D.; CALLAO LASMARIAS, MARÍA PILAR; Ruisánchez, I.; Gondim, C.D.S.; Junqueira, R.G.; Souza, S.V.C.D.; Callao, M.P.

    2017-01-01

    DOI: 10.1016/j.foodchem.2017.03.022 URL: http://www.sciencedirect.com/science/article/pii/S0308814617303874 Filiació URV: SI A sequential strategy was proposed to detect adulterants in milk using a mid-infrared spectroscopy and soft independent modelling of class analogy technique. Models were set with low target levels of adulterations including formaldehyde (0.074 g.L−1), hydrogen peroxide (21.0 g.L−1), bicarbonate (4.0 g.L−1), carbonate (4.0 g.L−1), chloride (5.0 g.L−1), citrate ...

  12. Continuous ground-based aerosol Lidar observation during seasonal pollution events at Wuxi, China

    Science.gov (United States)

    Wong, Man Sing; Qin, Kai; Lian, Hong; Campbell, James R.; Lee, Kwon Ho; Sheng, Shijie

    2017-04-01

    Haze pollution has long been a significant research topic and challenge in China, with adverse effects on air quality, agricultural production, as well as human health. In coupling with ground-based Lidar measurements, air quality observation, meteorological data, and backward trajectories model, two typical haze events at Wuxi, China are analyzed respectively, depicting summer and winter scenarios. Results indicate that the winter haze pollution is a compound pollution process mainly affected by calm winds that induce pollution accumulation near the surface. In the summer case, with the exception of influence from PM2.5 concentrations, ozone is the main pollutant and regional transport is also a significant influencing factor. Both events are marked by enhanced PM2.5 concentrations, driven by anthropogenic emissions of pollutants such as vehicle exhaust and factory fumes. Meteorological factors such as wind speed/direction and relative humidity are also contributed. These results indicate how the vertical profile offered by routine regional Lidar monitoring helps aid in understanding local variability and trends, which may be adapted for developing abatement strategies that improve air quality.

  13. Time series inversion of spectra from ground-based radiometers

    Directory of Open Access Journals (Sweden)

    O. M. Christensen

    2013-07-01

    Full Text Available Retrieving time series of atmospheric constituents from ground-based spectrometers often requires different temporal averaging depending on the altitude region in focus. This can lead to several datasets existing for one instrument, which complicates validation and comparisons between instruments. This paper puts forth a possible solution by incorporating the temporal domain into the maximum a posteriori (MAP retrieval algorithm. The state vector is increased to include measurements spanning a time period, and the temporal correlations between the true atmospheric states are explicitly specified in the a priori uncertainty matrix. This allows the MAP method to effectively select the best temporal smoothing for each altitude, removing the need for several datasets to cover different altitudes. The method is compared to traditional averaging of spectra using a simulated retrieval of water vapour in the mesosphere. The simulations show that the method offers a significant advantage compared to the traditional method, extending the sensitivity an additional 10 km upwards without reducing the temporal resolution at lower altitudes. The method is also tested on the Onsala Space Observatory (OSO water vapour microwave radiometer confirming the advantages found in the simulation. Additionally, it is shown how the method can interpolate data in time and provide diagnostic values to evaluate the interpolated data.

  14. Use of ground-based wind profiles in mesoscale forecasting

    Science.gov (United States)

    Schlatter, Thomas W.

    1985-01-01

    A brief review is presented of recent uses of ground-based wind profile data in mesoscale forecasting. Some of the applications are in real time, and some are after the fact. Not all of the work mentioned here has been published yet, but references are given wherever possible. As Gage and Balsley (1978) point out, sensitive Doppler radars have been used to examine tropospheric wind profiles since the 1970's. It was not until the early 1980's, however, that the potential contribution of these instruments to operational forecasting and numerical weather prediction became apparent. Profiler winds and radiosonde winds compare favorably, usually within a few m/s in speed and 10 degrees in direction (see Hogg et al., 1983), but the obvious advantage of the profiler is its frequent (hourly or more often) sampling of the same volume. The rawinsonde balloon is launched only twice a day and drifts with the wind. In this paper, I will: (1) mention two operational uses of data from a wind profiling system developed jointly by the Wave Propagation and Aeronomy Laboratories of NOAA; (2) describe a number of displays of these same data on a workstation for mesoscale forecasting developed by the Program for Regional Observing and Forecasting Services (PROFS); and (3) explain some interesting diagnostic calculations performed by meteorologists of the Wave Propagation Laboratory.

  15. Environmental impacts of PV systems -- Ground-based vs BIPV

    International Nuclear Information System (INIS)

    Baumann, A.E.; Hill, R.; Hynes, K.M.

    1997-01-01

    This study is part of the ExternE program of the European Commission on the external costs of the photovoltaic (PV) fuel cycle. The objective of this paper is the quantitative evaluation of the main environmental impacts of two selected PV systems--the ground-based 1MWp system in Toledo, Spain and the 40 kWp building integrated facade in Newcastle upon Tyne, NE England, using the methodology of life cycle analysis (LCA). Both systems use silicon wafer technology at present, but the Newcastle facade was also studied with the incorporation CdTe modules. The results of the LCA show that atmospheric emissions are the priority impacts with respect to the assessed PV systems. Comparing Si wafer systems, the CO 2 emissions were 88 t/GWh for the Toledo PV plant and 143t/GWh for the BIPV facade. If the facade had used electrodeposited CdTe, the CO 2 emissions would fall to about 50t/GWh

  16. Characterizing GEO Titan Transtage Fragmentations using Ground-based Measurements

    Science.gov (United States)

    Cowardin, H.; Anz-Meador, P.

    2016-01-01

    In a continued effort to better characterize the Geosynchronous Orbit (GEO) environment, NASA's Orbital Debris Program Office (ODPO) utilizes various ground-based optical assets to acquire photometric and spectral data of known debris associated with fragmentations in or near GEO. The Titan IIIC Transtage upper stage is known to have fragmented four times. Two of the four fragmentations were in GEO while a third Transtage fragmented in GEO transfer orbit. The forth fragmentation occurred in Low Earth Orbit. In order to better assess what may be causing these fragmentations, the NASA ODPO recently acquired a Titan Transtage test and display article that was previously in the custody of the 309th Aerospace Maintenance and Regeneration Group (AMARG) in Tucson, Arizona. After initial inspections at AMARG demonstrated that the test article was of sufficient fidelity to be of interest, the test article was brought to JSC to continue material analysis and historical documentation of the Titan Transtage. The Transtage will be a subject of forensic analysis using spectral measurements to compare with telescopic data; as well, a scale model will be created to use in the Optical Measurement Center for photometric analysis of an intact Transtage, including a BRDF. The following presentation will provide a review of the Titan Transtage, the current analysis that has been done to date, and the future work to be completed in support of characterizing the GEO and near GEO orbital debris environment.

  17. Ground-based measurements of UV Index (UVI at Helwan

    Directory of Open Access Journals (Sweden)

    H. Farouk

    2012-12-01

    Full Text Available On October 2010 UV Index (UVI ground-based measurements were carried out by weather station at solar laboratory in NRIAG. The daily variation has maximum values in spring and summer days, while minimum values in autumn and winter days. The low level of UVI between 2.55 and 2.825 was found in December, January and February. The moderate level of UVI between 3.075 and 5.6 was found in March, October and November. The high level of UVI between 6.7 and 7.65 was found in April, May and September. The very high level of UVI between 8 and 8.6 was found in June, July and August. High level of radiation over 6 months per year including 3 months with a very high level UVI. According to the equation {UVI=a[SZA]b} the UVI increases with decreasing SZA by 82% on a daily scale and 88% on a monthly scale. Helwan exposure to a high level of radiation over 6 months per year including 3 months with a very high level UVI, so it is advisable not to direct exposure to the sun from 11 am to 2:00 pm.

  18. An improved labeling strategy enables automated detection of single-virus fusion and assessment of HIV-1 protease activity in single virions.

    Science.gov (United States)

    Sood, Chetan; Francis, Ashwanth C; Desai, Tanay M; Melikyan, Gregory B

    2017-12-08

    Enveloped viruses transfer their genomes into host cells by fusing their membrane to that of the cell. To visualize single-virus fusion in living cells, researchers take advantage of the proteolytic maturation of HIV, type 1 (HIV-1), which can generate free fluorescent proteins within the viral particle. Co-labeling viruses with a content marker and a fluorescently tagged Vpr (a viral core protein) enables detection of single-virus fusions, but a major limitation of this approach is that not all viral particles incorporate both markers. Here we designed a labeling strategy based on the bifunctional mCherry-2xCL-YFP-Vpr construct, in which 2xCL denotes a tandem cleavage site for the viral protease. This bifunctional marker was efficiently cleaved during virus maturation, producing free mCherry and the core-associated YFP-Vpr. A nearly perfect colocalization of these two markers in virions and their fixed 1:1 ratio enabled automated detection of single-particle fusion in both fixed and live cells based on loss of the mCherry signal. Furthermore, a drop in FRET efficiency between YFP and mCherry because of cleavage of the bifunctional marker, which manifested as a marked shift in the normalized YFP/mCherry fluorescence ratio, reliably predicted viral protease activity in single virions. This feature could discriminate between the particles containing free mCherry, and therefore likely representing mature viruses, and immature particles whose fusion cannot be detected. In summary, our new labeling strategy offers several advantages compared with previous approaches, including increased reliability and throughput of detection of viral fusion. We anticipate that our method will have significant utility for studying viral fusion and maturation. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  19. Defect detection in slab surface: a novel dual Charge-coupled Device imaging-based fuzzy connectedness strategy.

    Science.gov (United States)

    Zhao, Liming; Ouyang, Qi; Chen, Dengfu; Udupa, Jayaram K; Wang, Huiqian; Zeng, Yuebin

    2014-11-01

    To provide an accurate surface defects inspection system and make the automation of robust image segmentation method a reality in routine production line, a general approach is presented for continuous casting slab (CC-slab) surface defects extraction and delineation. The applicability of the system is not tied to CC-slab exclusively. We combined the line array CCD (Charge-coupled Device) traditional scanning imaging (LS-imaging) and area array CCD laser three-dimensional (3D) scanning imaging (AL-imaging) strategies in designing the system. Its aim is to suppress the respective imaging system's limitations. In the system, the images acquired from the two CCD sensors are carefully aligned in space and in time by maximum mutual information-based full-fledged registration schema. Subsequently, the image information is fused from these two subsystems such as the unbroken 2D information in LS-imaging and 3D depressed information in AL-imaging. Finally, on the basis of the established dual scanning imaging system the region of interest (ROI) localization by seed specification was designed, and the delineation for ROI by iterative relative fuzzy connectedness (IRFC) algorithm was utilized to get a precise inspection result. Our method takes into account the complementary advantages in the two common machine vision (MV) systems and it performs competitively with the state-of-the-art as seen from the comparison of experimental results. For the first time, a joint imaging scanning strategy is proposed for CC-slab surface defect inspection that allows a feasible way of powerful ROI delineation strategies to be applied to the MV inspection field. Multi-ROI delineation by using IRFC in this research field may further improve the results.

  20. Evaluation of tropospheric and stratospheric ozone trends over Western Europe from ground-based FTIR network observations

    Directory of Open Access Journals (Sweden)

    C. Vigouroux

    2008-12-01

    Full Text Available Within the European project UFTIR (Time series of Upper Free Troposphere observations from an European ground-based FTIR network, six ground-based stations in Western Europe, from 79° N to 28° N, all equipped with Fourier Transform infrared (FTIR instruments and part of the Network for the Detection of Atmospheric Composition Change (NDACC, have joined their efforts to evaluate the trends of several direct and indirect greenhouse gases over the period 1995–2004. The retrievals of CO, CH4, C2H6, N2O, CHClF2, and O3 have been optimized. Using the optimal estimation method, some vertical information can be obtained in addition to total column amounts. A bootstrap resampling method has been implemented to determine annual partial and total column trends for the target gases. The present work focuses on the ozone results. The retrieved time series of partial and total ozone columns are validated with ground-based correlative data (Brewer, Dobson, UV-Vis, ozonesondes, and Lidar. The observed total column ozone trends are in agreement with previous studies: 1 no total column ozone trend is seen at the lowest latitude station Izaña (28° N; 2 slightly positive total column trends are seen at the two mid-latitude stations Zugspitze and Jungfraujoch (47° N, only one of them being significant; 3 the highest latitude stations Harestua (60° N, Kiruna (68° N and Ny-Ålesund (79° N show significant positive total column trends. Following the vertical information contained in the ozone FTIR retrievals, we provide partial columns trends for the layers: ground-10 km, 10–18 km, 18–27 km, and 27–42 km, which helps to distinguish the contributions from dynamical and chemical changes on the total column ozone trends. We obtain no statistically significant trends in the ground-10 km layer for five out of the six ground-based stations. We find significant positive trends for the lowermost

  1. Hybrid Integration of Magnetoresistive Sensors with MEMS as a Strategy to Detect Ultra-Low Magnetic Fields

    Directory of Open Access Journals (Sweden)

    João Valadeiro

    2016-05-01

    Full Text Available In this paper, we describe how magnetoresistive sensors can be integrated with microelectromechanical systems (MEMS devices enabling the mechanical modulation of DC or low frequency external magnetic fields to high frequencies using MEMS structures incorporating magnetic flux guides. In such a hybrid architecture, lower detectivities are expected when compared with those obtained for individual sensors. This particularity results from the change of sensor’s operating point to frequencies above the 1/f noise knee.

  2. Strategy of thunderstorm measurement with super dense ground-based observation network

    Science.gov (United States)

    Takahashi, Y.; Sato, M.

    2014-12-01

    It's not easy to understand the inside structure and developing process of thunderstorm only with existing meteorological instruments since its horizontal extent of the storm cell is sometimes smaller than an order of 10 km while one of the densest ground network in Japan, AMEDAS, consists of sites located every 17 km in average and the resolution of meteorological radar is 1-2 km in general. Even the X-band radar realizes the resolution of 250 m or larger. Here we suggest a new super dense observation network with simple and low cost sensors that can be used for measurement both of raindrop and vertical electric field change caused by cloud-to-ground lightning discharge. This sensor consists of two aluminum plates with a diameter of 10-20 cm. We carried out an observation campaign in summer of 2013 in the foothills of Mt. Yastugatake, Yamanashi and Nagano prefectures in Japan, installing 6 plate-type sensors at a distance of about 4 km. Horizontal location, height and charge amount of each lightning discharge are estimated successfully based on the information of electric field changes at several observing sites. Moreover, it was found that the thunderstorm has a very narrow structure well smaller than 300 m that cannot be measured by any other ways, counting the positive and negative pulses caused by attachment of raindrop to the sensor plate, respectively. We plan to construct a new super dense observation network in the north Kanto region, Japan, where the lightning activity is most prominent in summer Japan, distributing more than several tens of sensors at every 4 km or shorter, such as an order of 100 m at minimum. This kind of new type network will reveal the unknown fine structures of thunderstorms and open the door for constructing real time alert system of torrential rainfall and lightning stroke especially in the city area.

  3. Incorporating β-Cyclodextrin with ZnO Nanorods: A Potentiometric Strategy for Selectivity and Detection of Dopamine

    Directory of Open Access Journals (Sweden)

    Sami Elhag

    2014-01-01

    Full Text Available We describe a chemical sensor based on a simple synthesis of zinc oxide nanorods (ZNRs for the detection of dopamine molecules by a potentiometric approach. The polar nature of dopamine leads to a change of surface charges on the ZNR surface via metal ligand bond formation which results in a measurable electrical signal. ZNRs were grown on a gold-coated glass substrate by a low temperature aqueous chemical growth (ACG method. Polymeric membranes incorporating β-cyclodextrin (β-CD and potassium tetrakis (4-chlorophenyl borate was immobilized on the ZNR surface. The fabricated electrodes were characterized by X-ray diffraction (XRD and scanning electron microscopy (SEM techniques. The grown ZNRs were well aligned and exhibited good crystal quality. The present sensor system displays a stable potential response for the detection of dopamine in 10−2 mol·L−1 acetic acid/sodium acetate buffer solution at pH 5.45 within a wide concentration range of 1 × 10−6 M–1 × 10−1 M, with sensitivity of 49 mV/decade. The electrode shows a good response time (less than 10 s and excellent repeatability. This finding can contribute to routine analysis in laboratories studying the neuropharmacology of catecholamines. Moreover, the metal-ligand bonds can be further exploited to detect DA receptors, and for bio-imaging applications.

  4. Strategy for Accurate Detection of Escherichia Coli O157:H7 in Ground Pork Using a Lateral Flow Immunoassay.

    Science.gov (United States)

    Cheng, Song; Chen, Ming-Hui; Zhang, Gang-Gang; Yu, Zhi-Biao; Liu, Dao-Feng; Xiong, Yong-Hua; Wei, Hua; Lai, Wei-Hua

    2017-04-02

    Escherichia coli O157:H7 is known to cause serious diseases including hemorrhagic colitis and hemolytic uremic syndrome. A gold nanoparticle lateral flow immunoassay (Au-LFIA) was used to detect Escherichia coli O157:H7 in ground pork samples. False-positive results were detected using Au-LFIA; a Citrobacter freundii strain was isolated from the ground pork samples and identified by using CHROmagar TM plates, API 20E, and 16S RNA sequencing. Since C. freundii showed cross-reactivity with E. coli O157:H7 when Au-LFIA test strips were used, a novel method combining modified enrichment with a lateral flow immunoassay for accurate and convenient detection of E. coli O157:H7 in ground pork was developed in this study to minimize these false positives. MacConkey broth was optimized for E. coli O157:H7 enrichment and C. freundii inhibition by the addition of 5 mg/L potassium tellurite and 0.10 mg/L cefixime. Using the proposed modified enrichment procedure, the false-positive rate of ground pork samples spiked with 100 CFU/g C. freundii decreased to 5%.

  5. Strategy for Accurate Detection of Escherichia Coli O157:H7 in Ground Pork Using a Lateral Flow Immunoassay

    Directory of Open Access Journals (Sweden)

    Song Cheng

    2017-04-01

    Full Text Available Escherichia coli O157:H7 is known to cause serious diseases including hemorrhagic colitis and hemolytic uremic syndrome. A gold nanoparticle lateral flow immunoassay (Au-LFIA was used to detect Escherichia coli O157:H7 in ground pork samples. False-positive results were detected using Au-LFIA; a Citrobacter freundii strain was isolated from the ground pork samples and identified by using CHROmagarTM plates, API 20E, and 16S RNA sequencing. Since C. freundii showed cross-reactivity with E. coli O157:H7 when Au-LFIA test strips were used, a novel method combining modified enrichment with a lateral flow immunoassay for accurate and convenient detection of E. coli O157:H7 in ground pork was developed in this study to minimize these false positives. MacConkey broth was optimized for E. coli O157:H7 enrichment and C. freundii inhibition by the addition of 5 mg/L potassium tellurite and 0.10 mg/L cefixime. Using the proposed modified enrichment procedure, the false-positive rate of ground pork samples spiked with 100 CFU/g C. freundii decreased to 5%.

  6. DEM Development from Ground-Based LiDAR Data: A Method to Remove Non-Surface Objects

    Directory of Open Access Journals (Sweden)

    Maneesh Sharma

    2010-11-01

    Full Text Available Topography and land cover characteristics can have significant effects on infiltration, runoff, and erosion processes on watersheds. The ability to model the timing and routing of surface water and erosion is affected by the resolution of the digital elevation model (DEM. High resolution ground-based Light Detecting and Ranging (LiDAR technology can be used to collect detailed topographic and land cover characteristic data. In this study, a method was developed to remove vegetation from ground-based LiDAR data to create high resolution DEMs. Research was conducted on intensively studied rainfall–runoff plots on the USDA-ARS Walnut Gulch Experimental Watershed in Southeast Arizona. LiDAR data were used to generate 1 cm resolution digital surface models (DSM for 5 plots. DSMs created directly from LiDAR data contain non-surface objects such as vegetation cover. A vegetation removal method was developed which used a slope threshold and a focal mean filter method to remove vegetation and create bare earth DEMs. The method was validated on a synthetic plot, where rocks and vegetation were added incrementally. Results of the validation showed a vertical error of ±7.5 mm in the final DEM.

  7. GLM Proxy Data Generation: Methods for Stroke/Pulse Level Inter-Comparison of Ground-Based Lightning Reference Networks

    Science.gov (United States)

    Cummins, Kenneth L.; Carey, Lawrence D.; Schultz, Christopher J.; Bateman, Monte G.; Cecil, Daniel J.; Rudlosky, Scott D.; Petersen, Walter Arthur; Blakeslee, Richard J.; Goodman, Steven J.

    2011-01-01

    In order to produce useful proxy data for the GOES-R Geostationary Lightning Mapper (GLM) in regions not covered by VLF lightning mapping systems, we intend to employ data produced by ground-based (regional or global) VLF/LF lightning detection networks. Before using these data in GLM Risk Reduction tasks, it is necessary to have a quantitative understanding of the performance of these networks, in terms of CG flash/stroke DE, cloud flash/pulse DE, location accuracy, and CLD/CG classification error. This information is being obtained through inter-comparison with LMAs and well-quantified VLF/LF lightning networks. One of our approaches is to compare "bulk" counting statistics on the spatial scale of convective cells, in order to both quantify relative performance and observe variations in cell-based temporal trends provided by each network. In addition, we are using microsecond-level stroke/pulse time correlation to facilitate detailed inter-comparisons at a more-fundamental level. The current development status of our ground-based inter-comparison and evaluation tools will be presented, and performance metrics will be discussed through a comparison of Vaisala s Global Lightning Dataset (GLD360) with the NLDN at locations within and outside the U.S.

  8. Subtropical and Polar Cirrus Clouds Characterized by Ground-Based Lidars and CALIPSO/CALIOP Observations

    Directory of Open Access Journals (Sweden)

    Córdoba-Jabonero Carmen

    2016-01-01

    Full Text Available Cirrus clouds are product of weather processes, and then their occurrence and macrophysical/optical properties can vary significantly over different regions of the world. Lidars can provide height-resolved measurements with a relatively good both vertical and temporal resolutions, making them the most suitable instrumentation for high-cloud observations. The aim of this work is to show the potential of lidar observations on Cirrus clouds detection in combination with a recently proposed methodology to retrieve the Cirrus clouds macrophysical and optical features. In this sense, a few case studies of cirrus clouds observed at both subtropical and polar latitudes are examined and compared to CALIPSO/CALIOP observations. Lidar measurements are carried out in two stations: the Metropolitan city of Sao Paulo (MSP, Brazil, 23.3°S 46.4°W, located at subtropical latitudes, and the Belgrano II base (BEL, Argentina, 78ºS 35ºW in the Antarctic continent. Optical (COD-cloud optical depth and LR-Lidar Ratio and macrophysical (top/base heights and thickness properties of both the subtropical and polar cirrus clouds are reported. In general, subtropical Cirrus clouds present lower LR values and are found at higher altitudes than those detected at polar latitudes. In general, Cirrus clouds are detected at similar altitudes by CALIOP. However, a poor agreement is achieved in the LR retrieved between ground-based lidars and space-borne CALIOP measurements, likely due to the use of a fixed (or low-variable LR value in CALIOP inversion procedures.

  9. Ground-Based Phase of Spaceflight Experiment "Biosignal" Using Autonomic Microflurimeter "Fluor-K"

    Science.gov (United States)

    Grigorieva, O. V.; Gal'chuk, S. V.; Rudimov, E. G.; Buravkova, L. B.

    2013-02-01

    The majority of flight experiments with the use of cell cultures and equipment like KUBIK and CRIOGEM carried out on board of the satellites (Bion, Foton) and ISS only allows the after-flight biosamples to be analyzed. As far as with few exceptions, the real-time cellular parameters registration for a long period is hard to be implemented. We developed the "Fluor-K" equipment - precision, small-sized, autonomous, two-channel, programmed fluorimeter. This device is designed for registration of differential fluorescent signal from organic and non-organic objects of microscale in small volumes (cellular organelles suspensions, animal and human cells, unicellular algae, bacteria, various fluorescent colloid solutions). Beside that, "Fluor-K" allows simultaneous detection of temperature. The ground-based tests of the device proved successful. The developed software can support experimental schedules while real-time data registration with the built-in storage device allows changes in selected parameters to be analyzed using wide range of fluorescent probes.

  10. a Ground-Based LIDAR and Imaging Spectrometer Synchronous Experiment on Vegetation

    Science.gov (United States)

    Hong, T.; Luo, X.; Chen, H.; Hui, J.

    2017-09-01

    Extraction of vegetation canopy structure parameters is of great significance for researching global ecosystem and environment. Focused on the effective synergy between active and passive sensors, we carried out some ground-based observations about different vegetation on different terrains. In different experimental sites, a light detection and ranging (LiDAR) data and an imaging spectrum data of typical vegetation were collected from different directions and angles. Meanwhile, a variety of canopy structure parameters, including plant height, crown breadth, leaf area index, etc, were measured. The whole observed results form a comprehensive ground synchronous data set corresponding to flight data and provide data support for development and validation of synergic retrieval methods of vegetation canopy structure parameters. Our specific experimental objectives and design are introduced, including the selection of sampling plots, arrangement of observation stations, acquisition of active and passive data, and measurement of auxiliary data. The processing and practical applications of those obtained synchronous data are also discussed. Finally, our experimental experience is summarized and it is a valuable reference for remote sensing researchers.

  11. Evidence of rock slope breathing using ground-based InSAR

    Science.gov (United States)

    Rouyet, Line; Kristensen, Lene; Derron, Marc-Henri; Michoud, Clément; Blikra, Lars Harald; Jaboyedoff, Michel; Lauknes, Tom Rune

    2017-07-01

    Ground-Based Interferometric Synthetic Aperture Radar (GB-InSAR) campaigns were performed in summer 2011 and 2012 in the Romsdalen valley (Møre & Romsdal county, western Norway) in order to assess displacements on Mannen/Børa rock slope. Located 1 km northwest, a second GB-InSAR system continuously monitors the large Mannen rockslide. The availability of two GB-InSAR positions creates a wide coverage of the rock slope, including a slight dataset overlap valuable for validation. A phenomenon of rock slope breathing is detected in a remote and hard-to-access area in mid-slope. Millimetric upward displacements are recorded in August 2011. Analysis of 2012 GB-InSAR campaign, combined with the large dataset from the continuous station, shows that the slope is affected by inflation/deflation phenomenon between 5 and 10 mm along the line-of-sight. The pattern is not homogenous in time and inversions of movement have a seasonal recurrence. These seasonal changes are confirmed by satellite InSAR observations and can possibly be caused by hydrogeological variations. In addition, combination of GB-InSAR results, in situ measurements and satellite InSAR analyses contributes to a better overview of movement distribution over the whole area.

  12. Simple and robust strategy for potentiometric detection of glucose using fluorinated phenylboronic acid self-assembled monolayer.

    Science.gov (United States)

    Matsumoto, Akira; Matsumoto, Hiroko; Maeda, Yasuhiro; Miyahara, Yuji

    2013-09-01

    Field effect transistor (FET) based signal-transduction (Bio-FET) is an emerging technique for label-free and real-time basis biosensors for a wide range of targets. Glucose has constantly been of interest due to its clinical relevance. Use of glucose oxidase (GOD) and a lectin protein Concanavalin A are two common strategies to generate glucose-dependent electrochemical events. However, these protein-based materials are intolerant of long-term usage and storage due to their inevitable denaturing. A phenylboronic acid (PBA) modified self-assembled monolayer (SAM) on a gold electrode with an optimized disassociation constant of PBA, that is, 3-fluoro-4-carbamoyl-PBA possessing its pKa of 7.1, was prepared and utilized as an extended gate electrode for Bio-FET. The prepared electrode showed a glucose-dependent change in the surface potential under physiological conditions, thus providing a remarkably simple rationale for the glyco-sensitive Bio-FET. Importantly, the PBA modified electrode showed tolerance to relatively severe heat and drying treatments; conditions under which protein based materials would surely be denatured. A PBA modified SAM with optimized disassociation constant (pKa) can exhibit a glucose-dependent change in the surface potential under physiological conditions, providing a remarkably simple but robust method for the glyco-sensing. This protein-free, totally synthetic glyco-sensing strategy may offer cheap, robust and easily accessible platform that may be useful in developing countries. This article is part of a Special Issue entitled Organic Bioelectronics-Novel Applications in Biomedicine. Copyright © 2013 Elsevier B.V. All rights reserved.

  13. Ground-Based Global Navigation Satellite System Mixed Broadcast Ephemeris Data (daily files) from NASA CDDIS

    Data.gov (United States)

    National Aeronautics and Space Administration — This dataset consists of ground-based Global Navigation Satellite System (GNSS) Mixed Broadcast Ephemeris Data (daily files) from the NASA Crustal Dynamics Data...

  14. CLPX-Ground: Ground-based L and Ku band polarimetric scatterometry

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set includes ground-based radar observations carried out at the Fraser Experimental Forest Headquarters, Colorado, USA (39.95 N, 105.9 W), between 17-26...

  15. SAFARI 2000 AERONET Ground-based Aerosol Data, Dry Season 2000

    Data.gov (United States)

    National Aeronautics and Space Administration — AERONET (AErosol RObotic NETwork) is an optical ground-based aerosol monitoring network and data archive system. AERONET measurements of the column-integrated...

  16. Ground-Based Global Navigation Satellite System Combined Broadcast Ephemeris Data (hourly files) from NASA CDDIS

    Data.gov (United States)

    National Aeronautics and Space Administration — This dataset consists of ground-based Global Navigation Satellite System (GNSS) Combined Broadcast Ephemeris Data (hourly files of all distinct navigation messages...

  17. Ground-Based Global Navigation Satellite System Combined Broadcast Ephemeris Data (daily files) from NASA CDDIS

    Data.gov (United States)

    National Aeronautics and Space Administration — This dataset consists of ground-based Global Navigation Satellite System (GNSS) Combined Broadcast Ephemeris Data (daily files of all distinct navigation messages...

  18. Chasing Small Exoplanets with Ground-Based Near-Infrared Transit Photometry

    Science.gov (United States)

    Colon, K. D.; Barentsen, G.; Vinicius, Z.; Vanderburg, A.; Coughlin, J.; Thompson, S.; Mullally, F.; Barclay, T.; Quintana, E.

    2017-11-01

    I will present results from a ground-based survey to measure the infrared radius and other properties of small K2 exoplanets and candidates. The survey is preparation for upcoming discoveries from TESS and characterization with JWST.

  19. Power allocation for target detection in radar networks based on low probability of intercept: A cooperative game theoretical strategy

    Science.gov (United States)

    Shi, Chenguang; Salous, Sana; Wang, Fei; Zhou, Jianjiang

    2017-08-01

    Distributed radar network systems have been shown to have many unique features. Due to their advantage of signal and spatial diversities, radar networks are attractive for target detection. In practice, the netted radars in radar networks are supposed to maximize their transmit power to achieve better detection performance, which may be in contradiction with low probability of intercept (LPI). Therefore, this paper investigates the problem of adaptive power allocation for radar networks in a cooperative game-theoretic framework such that the LPI performance can be improved. Taking into consideration both the transmit power constraints and the minimum signal to interference plus noise ratio (SINR) requirement of each radar, a cooperative Nash bargaining power allocation game based on LPI is formulated, whose objective is to minimize the total transmit power by optimizing the power allocation in radar networks. First, a novel SINR-based network utility function is defined and utilized as a metric to evaluate power allocation. Then, with the well-designed network utility function, the existence and uniqueness of the Nash bargaining solution are proved analytically. Finally, an iterative Nash bargaining algorithm is developed that converges quickly to a Pareto optimal equilibrium for the cooperative game. Numerical simulations and theoretic analysis are provided to evaluate the effectiveness of the proposed algorithm.

  20. Monitoring Hydraulic Fracturing Using Ground-Based Controlled Source Electromagnetics

    Science.gov (United States)

    Hickey, M. S.; Trevino, S., III; Everett, M. E.

    2017-12-01

    Hydraulic fracturing allows hydrocarbon production in low permeability formations. Imaging the distribution of fluid used to create a hydraulic fracture can aid in the characterization of fracture properties such as extent of plume penetration as well as fracture azimuth and symmetry. This could contribute to improving the efficiency of an operation, for example, in helping to determine ideal well spacing or the need to refracture a zone. A ground-based controlled-source electromagnetics (CSEM) technique is ideal for imaging the fluid due to the change in field caused by the difference in the conductive properties of the fluid when compared to the background. With advances in high signal to noise recording equipment, coupled with a high-power, broadband transmitter we can show hydraulic fracture extent and azimuth with minimal processing. A 3D finite element code is used to model the complete well casing along with the layered subsurface. This forward model is used to optimize the survey design and isolate the band of frequencies with the best response. In the field, the results of the modeling are also used to create a custom pseudorandom numeric (PRN) code to control the frequencies transmitted through a grounded dipole source. The receivers record the surface voltage across two grounded dipoles, one parallel and one perpendicular to the transmitter. The data are presented as the displays of amplitude ratios across several frequencies with the associated spatial information. In this presentation, we show multiple field results in multiple basins in the United States along with the CSEM theory used to create the survey designs.

  1. Elution strategies for reversed-phase high-performance liquid chromatography analysis of sucrose alkanoate regioisomers with charged aerosol detection.

    Science.gov (United States)

    Lie, Aleksander; Pedersen, Lars Haastrup

    2013-10-11

    A broad range of elution strategies for RP-HPLC analysis of sucrose alkanoate regioisomers with CAD was systematically evaluated. The HPLC analyses were investigated using design-of-experiments methodology and analysed by analysis of variance (ANOVA) and regression modelling. Isocratic elutions, isocratic elutions with increased flow, and gradient elutions with step-down profiles and step-up profiles were performed and the chromatographic parameters of the different elution strategies were described by suitable variables. Based on peak resolutions general resolution deviation for multiple peaks (RDm) was developed for sample-independent evaluation of separation of any number of peaks in chromatographic analysis. Isocratic elutions of sucrose alkanoates showed similar relationships between eluent acetonitrile concentration and retention time for all regioisomers of sucrose caprate and sucrose laurate, as confirmed by evaluation of the curvatures using approximate second derivatives and Kendall rank correlation coefficients. Regression modelling and statistical analysis showed that acetonitrile concentration and flow rate were highly significant for both average adjusted retention time and RDm for sucrose laurate. For both responses the effect of changes in acetonitrile concentration was larger than the effect of changes in flow rate, over the ranges studied. Regression modelling of the step-down gradient profiles for the sucrose alkanoates showed that the eluent acetonitrile concentrations were the overall most significant variables for retention time and separation. The models for average adjusted retention time of sucrose caprate and sucrose laurate showed only a few differences in the significance levels of terms, while the models for RDm showed larger differences between the sucrose alkanoates, in both the number of terms and their significance. Efficiency evaluation of elution strategies, in terms of RDm and analysis time, showed that the best results were

  2. Advances in alloimmune thrombocytopenia: perspectives on current concepts of human platelet antigens, antibody detection strategies, and genotyping.

    Science.gov (United States)

    Hayashi, Tomoya; Hirayama, Fumiya

    2015-07-01

    Alloimmunisation to platelets leads to the production of antibodies against platelet antigens and consequently to thrombocytopenia. Numerous molecules located on the platelet surface are antigenic and induce immune-mediated platelet destruction with symptoms that can be serious. Human platelet antigens (HPA) cause thrombocytopenias, such as neonatal alloimmune thrombocytopenia, post-transfusion purpura, and platelet transfusion refractoriness. Thirty-four HPA are classified into 28 systems. Assays to identify HPA and anti-HPA antibodies are critically important for preventing and treating thrombocytopenia caused by anti-HPA antibodies. Significant progress in furthering our understanding of HPA has been made in the last decade: new HPA have been discovered, antibody-detection methods have improved, and new genotyping methods have been developed. We review these advances and discuss issues that remain to be resolved as well as future prospects for preventing and treating immune thrombocytopenia.

  3. Ground-based photometry of the 21-day Neptune HD 106315c

    Science.gov (United States)

    Lendl, M.; Ehrenreich, D.; Turner, O. D.; Bayliss, D.; Blanco-Cuaresma, S.; Giles, H.; Bouchy, F.; Marmier, M.; Udry, S.

    2017-07-01

    Space-based transit surveys such as K2 and the Transiting Exoplanets Survey Satellite (TESS) allow the detection of small transiting planets with orbital periods greater than 10 days. Few of these warm Neptunes are currently known around stars bright enough to allow for detailed follow-up observations dedicated to their atmospheric characterization. The 21-day period and 3.95 R⊕ planet HD 106315c has been discovered by K2 based on the observation of two of its transits. We observed HD 106315 using the 1.2 m Euler telescope equipped with the EulerCam camera on two occasions to confirm the transit using broadband photometry and refine the planetary period. Based on two observed transits of HD 106315c, we detect its 1 mmag transit and obtain a precise measurement of the planetary ephemerides, which are critical for planning further follow-up observations. We used the attained precision together with the predicted yield from the TESS mission to evaluate the potential for ground-based confirmation of Neptune-sized planets found by TESS. We find that one-meter class telescopes on the ground equipped with precise photometers could substantially contribute to the follow-up of 162 TESS candidates orbiting stars with magnitudes of V ≤ 14. Of these candidates, 74 planets orbit stars with V ≤ 12 and 12 planets orbit V ≤ 10, which makes them high-priority objects for atmospheric characterization with high-end instrumentation. The photometric time series data are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/603/L5

  4. Tungsten disulfide nanosheet and exonuclease III co-assisted amplification strategy for highly sensitive fluorescence polarization detection of DNA glycosylase activity

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Jingjin; Ma, Yefei [Key Laboratory for the Chemistry and Molecular Engineering of Medicinal Resources of Education Ministry, Guangxi Normal University, Guilin, 541004 (China); Kong, Rongmei [The Key Laboratory of Life-Organic Analysis, College of Chemistry and Chemical Engineering, Qufu Normal University, Qufu, Shandong 273165 (China); Zhang, Liangliang, E-mail: liangzhang319@163.com [Key Laboratory for the Chemistry and Molecular Engineering of Medicinal Resources of Education Ministry, Guangxi Normal University, Guilin, 541004 (China); Yang, Wen; Zhao, Shulin [Key Laboratory for the Chemistry and Molecular Engineering of Medicinal Resources of Education Ministry, Guangxi Normal University, Guilin, 541004 (China)

    2015-08-05

    Herein, we introduced a tungsten disulfide (WS{sub 2}) nanosheet and exonuclease III (Exo III) co-assisted signal amplification strategy for highly sensitive fluorescent polarization (FP) assay of DNA glycosylase activity. Two DNA glycosylases, uracil-DNA glycosylase (UDG) and human 8-oxoG DNA glycosylase 1 (hOGG1), were tested. A hairpin-structured probe (HP) which contained damaged bases in the stem was used as the substrate. The removal of damaged bases from substrate by DNA glycosylase would lower the melting temperature of HP. The HP was then opened and hybridized with a FAM dye-labeled single strand DNA (DP), generating a duplex with a recessed 3′-terminal of DP. This design facilitated the Exo III-assisted amplification by repeating the hybridization and digestion of DP, liberating numerous FAM fluorophores which could not be adsorbed on WS{sub 2} nanosheet. Thus, the final system exhibited a small FP signal. However, in the absence of DNA glycosylases, no hybridization between DP and HP was occurred, hampering the hydrolysis of DP by Exo III. The intact DP was then adsorbed on the surface of WS{sub 2} nanosheet that greatly amplified the mass of the labeled-FAM fluorophore, resulting in a large FP value. With the co-assisted amplification strategy, the sensitivity was substantially improved. In addition, this method was applied to detect UDG activity in cell extracts. The study of the inhibition of UDG was also performed. Furthermore, this method is simple in design, easy in implementation, and selective, which holds potential applications in the DNA glycosylase related mechanism research and molecular diagnostics. - Highlights: • A fluorescence polarization strategy for DNA glycosylase activity detection was developed. • The present method was based on WS{sub 2} nanosheet and exonuclease III co-assisted signal amplification. • A high sensitivity and desirable selectivity were achieved. • This method provides a promising universal platform for DNA

  5. Protein modifications by electrophilic lipoxidation products: adduct formation, chemical strategies and tandem mass spectrometry for their detection and identification.

    Science.gov (United States)

    Vasil'ev, Yury V; Tzeng, Shin-Chen; Huang, Lin; Maier, Claudia S

    2014-01-01

    The post-translational modification of proteins by electrophilic oxylipids is emerging as an important mechanism that contributes to the complexity of proteomes. Enzymatic and non-enzymatic oxidation of biological lipids results in the formation of chemically diverse electrophilic carbonyl compounds, such as 2-alkenals and 4-hydroxy alkenals, epoxides, and eicosanoids with reactive cyclopentenone structures. These lipoxidation products are capable of modifying proteins. Originally considered solely as markers of oxidative insult, more recently the modifications of proteins by lipid peroxidation products are being recognized as a new mechanism of cell signaling with relevance to redox homeostasis, adaptive response and inflammatory resolution. The growing interest in protein modifications by reactive oxylipid species necessitates the availability of methods that are capable of detecting, identifying and characterizing these protein adducts in biological samples with high complexity. However, the efficient analysis of these chemically diverse protein adducts presents a considerable analytical challenge. We first provide an introduction into the chemistry and biological relevance of protein adductions by electrophilic lipoxidation products. We then provide an overview of tandem mass spectrometry approaches that have been developed in recent years for the interrogation of protein modifications by electrophilic oxylipid species. 2013 Wiley Periodicals, Inc.

  6. Recombinase polymerase and enzyme-linked immunosorbent assay as a DNA amplification-detection strategy for food analysis.

    Science.gov (United States)

    Santiago-Felipe, S; Tortajada-Genaro, L A; Puchades, R; Maquieira, A

    2014-02-06

    Polymerase chain reaction in conjunction with enzyme-linked immunosorbent assay (PCR-ELISA) is a well-established technique that provides a suitable rapid, sensitive, and selective method for a broad range of applications. However, the need for precise rapid temperature cycling of PCR is an important drawback that can be overcome by employing isothermal amplification reactions such as recombinase polymerase amplification (RPA). The RPA-ELISA combination is proposed for amplification at a low, constant temperature (40°C) in a short time (40 min), for the hybridisation of labelled products to specific 5'-biotinylated probes/streptavidin in coated microtiter plates at room temperature, and for detection by colorimetric immunoassay. RPA-ELISA was applied to screen common safety threats in foodstuffs, such as allergens (hazelnut, peanut, soybean, tomato, and maize), genetically modified organisms (P35S and TNOS), pathogenic bacteria (Salmonella sp. and Cronobacter sp.), and fungi (Fusarium sp.). Satisfactory sensitivity and reproducibility results were achieved for all the targets. The RPA-ELISA technique does away with thermocycling and provides a suitable sensitive, specific, and cost-effective method for routine applications, and proves particularly useful for resource-limited settings. Copyright © 2013 Elsevier B.V. All rights reserved.

  7. Computational reduction strategies for the detection of steady bifurcations in incompressible fluid-dynamics: Applications to Coanda effect in cardiology

    Science.gov (United States)

    Pitton, Giuseppe; Quaini, Annalisa; Rozza, Gianluigi

    2017-09-01

    We focus on reducing the computational costs associated with the hydrodynamic stability of solutions of the incompressible Navier-Stokes equations for a Newtonian and viscous fluid in contraction-expansion channels. In particular, we are interested in studying steady bifurcations, occurring when non-unique stable solutions appear as physical and/or geometric control parameters are varied. The formulation of the stability problem requires solving an eigenvalue problem for a partial differential operator. An alternative to this approach is the direct simulation of the flow to characterize the asymptotic behavior of the solution. Both approaches can be extremely expensive in terms of computational time. We propose to apply Reduced Order Modeling (ROM) techniques to reduce the demanding computational costs associated with the detection of a type of steady bifurcations in fluid dynamics. The application that motivated the present study is the onset of asymmetries (i.e., symmetry breaking bifurcation) in blood flow through a regurgitant mitral valve, depending on the Reynolds number and the regurgitant mitral valve orifice shape.

  8. A decadal cirrus clouds climatology from ground-based and spaceborne lidars above the south of France (43.9° N–5.7° E

    Directory of Open Access Journals (Sweden)

    C. Hoareau

    2013-07-01

    Full Text Available This study provides an analysis of cirrus cloud properties at midlatitude in the southern part of France from ground-based and spaceborne lidars. A climatology of cirrus cloud properties and their evolution over more than 12 yr is presented and compared to other mid-latitude climatological studies. Cirrus clouds occur ~37% of the total observation time and remain quasi-constant across seasons with a variation within ~5% around the mean occurrence. Similar results are obtained from CALIOP and the ground-based lidar, with a mean difference in occurrence of ~5% between both instruments. From the ground-based lidar data, a slight decrease in occurrence of ~3% per decade is observed but found statistically insignificant. Based on a clustering analysis of cirrus cloud parameters, three distinct classes have been identified and investigations concerning their origin are discussed. Properties of these different classes are analysed, showing that thin cirrus in the upper troposphere represent ~50% of cloud cover detected in summer and fall, decreasing by 15–20% for other seasons.

  9. One-pot evaporation–condensation strategy for green synthesis of carbon nitride quantum dots: An efficient fluorescent probe for ion detection and bioimaging

    International Nuclear Information System (INIS)

    Yin, Ying; Zhang, Yumin; Gao, Tangling; Yao, Tai; Han, Jiecai; Han, Zhengbin; Zhang, Zhihua; Wu, Qiong; Song, Bo

    2017-01-01

    Herein, highly blue graphitic carbon nitride quantum dots (g-CNQDs) were synthesized by one-step microwave-assisted evaporation–condensation strategy using bulk g-C 3 N 4 as the precursor within 5 min. In contrast with conventional chemical routes, the as-synthesized g-CNQDs exhibited a high crystalline quality, excellent fluorescence characteristics, and a narrow size distribution with an average diameter of 3.5 ± 0.5 nm. More importantly, by using a household microwave oven, this method has the advantages of wide accessibility, environmental friendliness, a high yield of ∼40%, and can be facilely synthesized in a large scale (scaled up to a gram scale). Notably, owing to the absence of any organic reagents, the blueas-prepared g-CNQDs show the excitation wavelength-independent photoluminescence (PL) behavior. Moreover, benefiting from the stable PL emission, good water solubility, and extraordinary biocompatibility with a high quantum yield of ∼17%, the fluorescent g-CNQDs can serve as a potential sensitive and selective probe for Fe 3+ detection with a super low detection limit of 2 nM and an effective labeling agent for live-cell imaging. This work provides a unique opportunity to obtain g-CNQDs in large scale via a facile route, which may pave the way for the further design of g-CNQDs with other applications. - Highlights: • Green synthesis of g-CNQDs via one-step evaporation-condensation method. • The g-CNQDs have shown high crystalline quality and intrinsic fluorescence features. • The fluorescent g-CNQDs can serve as a sensitive and selective probe to detect Fe 3+ ions with a low detection limit of 2 nM. • g-CNQDs can serve as an effective labeling agent for live-cell imaging with extraordinary biocompatibility.

  10. One-pot evaporation–condensation strategy for green synthesis of carbon nitride quantum dots: An efficient fluorescent probe for ion detection and bioimaging

    Energy Technology Data Exchange (ETDEWEB)

    Yin, Ying; Zhang, Yumin [Center for Composite Materials, Harbin Institute of Technology, Harbin 150001 (China); Gao, Tangling [Institute of Petrochemistry, Heilongjiang Academy of Sciences, Harbin 150040 (China); Yao, Tai [Academy of Fundamental and Interdisciplinary Sciences, Harbin Institute of Technology, Harbin 150001 (China); Han, Jiecai [Center for Composite Materials, Harbin Institute of Technology, Harbin 150001 (China); Han, Zhengbin, E-mail: hanzhengbin@hit.edu.cn [School of Life Science and Technology, Harbin Institute of Technology, Harbin 150001 (China); Zhang, Zhihua [Liaoning Key Materials Laboratory for Railway, School of Materials Science and Engineering, Dalian Jiaotong University, Dalian 116028 (China); Wu, Qiong [School of Life Science and Technology, Harbin Institute of Technology, Harbin 150001 (China); Song, Bo, E-mail: songbo@hit.edu.cn [Academy of Fundamental and Interdisciplinary Sciences, Harbin Institute of Technology, Harbin 150001 (China); Department of Physics, Harbin Institute of Technology, Harbin 150001 (China)

    2017-06-15

    Herein, highly blue graphitic carbon nitride quantum dots (g-CNQDs) were synthesized by one-step microwave-assisted evaporation–condensation strategy using bulk g-C{sub 3}N{sub 4} as the precursor within 5 min. In contrast with conventional chemical routes, the as-synthesized g-CNQDs exhibited a high crystalline quality, excellent fluorescence characteristics, and a narrow size distribution with an average diameter of 3.5 ± 0.5 nm. More importantly, by using a household microwave oven, this method has the advantages of wide accessibility, environmental friendliness, a high yield of ∼40%, and can be facilely synthesized in a large scale (scaled up to a gram scale). Notably, owing to the absence of any organic reagents, the blueas-prepared g-CNQDs show the excitation wavelength-independent photoluminescence (PL) behavior. Moreover, benefiting from the stable PL emission, good water solubility, and extraordinary biocompatibility with a high quantum yield of ∼17%, the fluorescent g-CNQDs can serve as a potential sensitive and selective probe for Fe{sup 3+} detection with a super low detection limit of 2 nM and an effective labeling agent for live-cell imaging. This work provides a unique opportunity to obtain g-CNQDs in large scale via a facile route, which may pave the way for the further design of g-CNQDs with other applications. - Highlights: • Green synthesis of g-CNQDs via one-step evaporation-condensation method. • The g-CNQDs have shown high crystalline quality and intrinsic fluorescence features. • The fluorescent g-CNQDs can serve as a sensitive and selective probe to detect Fe{sup 3+} ions with a low detection limit of 2 nM. • g-CNQDs can serve as an effective labeling agent for live-cell imaging with extraordinary biocompatibility.

  11. Recombinase polymerase and enzyme-linked immunosorbent assay as a DNA amplification-detection strategy for food analysis

    Energy Technology Data Exchange (ETDEWEB)

    Santiago-Felipe, S.; Tortajada-Genaro, L.A.; Puchades, R.; Maquieira, A., E-mail: amaquieira@qim.upv.es

    2014-02-06

    Graphical abstract: -- Highlights: •Recombinase polymerase amplification is a powerful DNA method operating at 40 °C. •The combination RPA–ELISA gives excellent performances for high-throughput analysis. •Screening of food safety threats has been done using standard laboratory equipment. •Allergens, GMOs, bacteria, and fungi have been successfully determined. -- Abstract: Polymerase chain reaction in conjunction with enzyme-linked immunosorbent assay (PCR–ELISA) is a well-established technique that provides a suitable rapid, sensitive, and selective method for a broad range of applications. However, the need for precise rapid temperature cycling of PCR is an important drawback that can be overcome by employing isothermal amplification reactions such as recombinase polymerase amplification (RPA). The RPA–ELISA combination is proposed for amplification at a low, constant temperature (40 °C) in a short time (40 min), for the hybridisation of labelled products to specific 5′-biotinylated probes/streptavidin in coated microtiter plates at room temperature, and for detection by colorimetric immunoassay. RPA–ELISA was applied to screen common safety threats in foodstuffs, such as allergens (hazelnut, peanut, soybean, tomato, and maize), genetically modified organisms (P35S and TNOS), pathogenic bacteria (Salmonella sp. and Cronobacter sp.), and fungi (Fusarium sp.). Satisfactory sensitivity and reproducibility results were achieved for all the targets. The RPA–ELISA technique does away with thermocycling and provides a suitable sensitive, specific, and cost-effective method for routine applications, and proves particularly useful for resource-limited settings.

  12. Recombinase polymerase and enzyme-linked immunosorbent assay as a DNA amplification-detection strategy for food analysis

    International Nuclear Information System (INIS)

    Santiago-Felipe, S.; Tortajada-Genaro, L.A.; Puchades, R.; Maquieira, A.

    2014-01-01

    Graphical abstract: -- Highlights: •Recombinase polymerase amplification is a powerful DNA method operating at 40 °C. •The combination RPA–ELISA gives excellent performances for high-throughput analysis. •Screening of food safety threats has been done using standard laboratory equipment. •Allergens, GMOs, bacteria, and fungi have been successfully determined. -- Abstract: Polymerase chain reaction in conjunction with enzyme-linked immunosorbent assay (PCR–ELISA) is a well-established technique that provides a suitable rapid, sensitive, and selective method for a broad range of applications. However, the need for precise rapid temperature cycling of PCR is an important drawback that can be overcome by employing isothermal amplification reactions such as recombinase polymerase amplification (RPA). The RPA–ELISA combination is proposed for amplification at a low, constant temperature (40 °C) in a short time (40 min), for the hybridisation of labelled products to specific 5′-biotinylated probes/streptavidin in coated microtiter plates at room temperature, and for detection by colorimetric immunoassay. RPA–ELISA was applied to screen common safety threats in foodstuffs, such as allergens (hazelnut, peanut, soybean, tomato, and maize), genetically modified organisms (P35S and TNOS), pathogenic bacteria (Salmonella sp. and Cronobacter sp.), and fungi (Fusarium sp.). Satisfactory sensitivity and reproducibility results were achieved for all the targets. The RPA–ELISA technique does away with thermocycling and provides a suitable sensitive, specific, and cost-effective method for routine applications, and proves particularly useful for resource-limited settings

  13. Spectroscopic analysis of stellar mass black-hole mergers in our local universe with ground-based gravitational wave detectors

    Science.gov (United States)

    Bhagwat, Swetha; Brown, Duncan; Ballmer, Stefan

    2017-01-01

    Motivated by the recent discoveries of binary black-hole mergers by the Advanced Laser Interferometer Gravitational-wave Observatory (Advanced LIGO), we investigate the prospects of ground based detectors to perform a spectroscopic analysis of signals emitted during the ringdown of the Kerr black-hole formed by a stellar mass binary black-hole merger. We investigate the detectability and resolvability of the sub-dominant modes l = m = 3, l = m = 4 and l = 2;m = 1. We find that new ground-based facilities such as Einstein Telescope or Cosmic Explorer could measure multiple ringdown modes in over 300 events per year. We also investigate detector tuning for ringdown oriented searches.

  14. Design of a multi-model observer-based estimator for Fault Detection and Isolation (FDI strategy: application to a chemical reactor

    Directory of Open Access Journals (Sweden)

    Y. Chetouani

    2008-12-01

    Full Text Available This study presents a FDI strategy for nonlinear dynamic systems. It shows a methodology of tackling the fault detection and isolation issue by combining a technique based on the residuals signal and a technique using the multiple Kalman filters. The usefulness of this combination is the on-line implementation of the set of models, which represents the normal mode and all dynamics of faults, if the statistical decision threshold on the residuals exceeds a fixed value. In other cases, one Extended Kalman Filter (EKF is enough to estimate the process state. After describing the system architecture and the proposed FDI methodology, we present a realistic application in order to show the technique's potential. An algorithm is described and applied to a chemical process like a perfectly stirred chemical reactor functioning in a semi-batch mode. The chemical reaction used is an oxido reduction one, the oxidation of sodium thiosulfate by hydrogen peroxide.

  15. Radiomics Strategy for Molecular Subtype Stratification of Lower-Grade Glioma: Detecting IDH and TP53 Mutations Based on Multimodal MRI.

    Science.gov (United States)

    Zhang, Xi; Tian, Qiang; Wang, Liang; Liu, Yang; Li, Baojuan; Liang, Zhengrong; Gao, Peng; Zheng, Kaizhong; Zhao, Bofeng; Lu, Hongbing

    2018-02-02

    Noninvasive detection of isocitrate dehydrogenase (IDH) and TP53 mutations are meaningful for molecular stratification of lower-grade gliomas (LrGG). To explore potential MRI features reflecting IDH and TP53 mutations of LrGG, and propose a radiomics strategy for detecting them. Retrospective, radiomics. A total of 103 LrGG patients were separated into development (n = 73) and validation (n = 30) cohorts. T 1 -weighted (before and after contrast-enhanced), T 2 -weighted, and fluid-attenuation inversion recovery images from 1.5T (n = 37) or 3T (n = 66) scanners. After data preprocessing, high-throughput features were derived from patients' volumes of interests of different sequences. The support vector machine-based recursive feature elimination (SVM-RFE) was adopted to find the optimal features for IDH and TP53 mutation detection. SVM models were trained and tested on development and validation cohort. The commonly used metric was used for assessing the efficiency. One-way analysis of variance (ANOVA), chi-square, or Fisher's exact test were applied on clinical characteristics to confirm whether significant differences exist between three molecular subtypes decided by IDH and TP53 status. Intraclass correlation coefficients were calculated to assess the robustness of the radiomics features. The constituent ratio of histopathologic subtypes was significantly different among three molecular subtypes (P = 0.017). SVM models for detecting IDH and TP53 mutation were established using 12 and 22 optimal features selected by SVM-RFE. The accuracies and area under the curves for IDH and TP53 mutations on the development cohort were 84.9%, 0.830, and 92.0%, 0.949, while on the validation cohort were 80.0%, 0.792, and 85.0%, 0.869, respectively. Furthermore, the stratified accuracies of three subtypes were 72.8%, 71.9%, and 70%, respectively. Using a radiomics approach integrating SVM model and multimodal MRI features, molecular subtype stratification of

  16. Precise Orbits for Ground-Based GPS Meteorology : Processing Strategy and Quality Assessment of the Orbits Determined at Geodetic Observatory Pecny (1.Ground-Based GPS Meteorology)

    OpenAIRE

    Jan, DOUSA; Research Institute of Geodesy, Topography and Cartography:Dept. Of Advanced Geodesy, Czech Technical University in Prague

    2004-01-01

    The GPS meteorology has been the driving force behind the near real-time (NRT) GPS analyses during the past few years. High availability of precise near real-time GPS orbits is essential for obtaining reliable solutions in almost all applications. This is especially true when estimating the troposphere parameters. Besides the demand on high accuracy, the orbit products should stand out for their stability in production as well as for their completeness in set of satellites. The most likely ca...

  17. Detection of several common adulterants in raw milk by MID-infrared spectroscopy and one-class and multi-class multivariate strategies.

    Science.gov (United States)

    Gondim, Carina de Souza; Junqueira, Roberto Gonçalves; Souza, Scheilla Vitorino Carvalho de; Ruisánchez, Itziar; Callao, M Pilar

    2017-09-01

    A sequential strategy was proposed to detect adulterants in milk using a mid-infrared spectroscopy and soft independent modelling of class analogy technique. Models were set with low target levels of adulterations including formaldehyde (0.074g.L -1 ), hydrogen peroxide (21.0g.L -1 ), bicarbonate (4.0g.L -1 ), carbonate (4.0g.L -1 ), chloride (5.0g.L -1 ), citrate (6.5g.L -1 ), hydroxide (4.0g.L -1 ), hypochlorite (0.2g.L -1 ), starch (5.0g.L -1 ), sucrose (5.4g.L -1 ) and water (150g.L -1 ). In the first step, a one-class model was developed with unadulterated samples, providing 93.1% sensitivity. Four poorly assigned adulterants were discarded for the following step (multi-class modelling). Then, in the second step, a multi-class model, which considered unadulterated and formaldehyde-, hydrogen peroxide-, citrate-, hydroxide- and starch-adulterated samples was implemented, providing 82% correct classifications, 17% inconclusive classifications and 1% misclassifications. The proposed strategy was considered efficient as a screening approach since it would reduce the number of samples subjected to confirmatory analysis, time, costs and errors. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Blowing snow detection from ground-based ceilometers : Application to East Antarctica

    NARCIS (Netherlands)

    Gossart, Alexandra; Souverijns, Niels; Gorodetskaya, Irina V.; Lhermitte, S.L.M.; Lenaerts, Jan T M; Schween, Jan H.; Mangold, Alexander; Laffineur, Quentin; van Lipzig, Nicole P. M.

    2017-01-01

    Blowing snow impacts Antarctic ice sheet surface mass balance by snow redistribution and sublimation. However, numerical models poorly represent blowing snow processes, while direct observations are limited in space and time. Satellite retrieval of blowing snow is hindered by clouds and only the

  19. MicroRNA Expression can be a Promising Strategy for the Detection of Barrett's Esophagus: A Pilot Study.

    Science.gov (United States)

    Bansal, Ajay; Hong, Xiaoman; Lee, In-Hee; Krishnadath, Kausilia K; Mathur, Sharad C; Gunewardena, Sumedha; Rastogi, Amit; Sharma, Prateek; Christenson, Lane K

    2014-12-11

    R-194-5p, 91% and 94%, AUC 0.96 (0.80-0.99, P=0.0001), respectively. The tested miRNAs identified all BE patients in both the discovery and the validation cohorts. When compared with non intestinal-type columnar and gastric cardia epithelia, the miRNA signature was specific to the intestinal-type columnar epithelium. Comparisons of BE miRNA sequencing data to published data sets for the normal stomach, small intestine and large intestine confirmed that two of the three miRNAs (miR-215-5p and -194-5p) were specific to the intestinal-type epithelium. MicroRNAs are highly accurate for detecting intestinal-type BE epithelia and should be tested further for the non-endoscopic molecular diagnosis of BE.

  20. Development of a monoclonal antibody against the left wing of ciguatoxin CTX1B: thiol strategy and detection using a sandwich ELISA.

    Science.gov (United States)

    Tsumuraya, Takeshi; Takeuchi, Katsutoshi; Yamashita, Shuji; Fujii, Ikuo; Hirama, Masahiro

    2012-09-01

    Ciguatera fish poisoning (CFP) is a form of food poisoning caused by the ingestion of a variety of reef fish that have accumulated trace amounts of ciguatoxins produced by dinoflagellates of the genus Gambierdiscus through the food chain. CFP affects more than 50,000 people each year. The extremely low level of the causative neurotoxins, ciguatoxins, in fish has hampered the preparation of antibodies for detecting the toxins. In this paper, we describe a thiol strategy for synthesizing a keyhole limpet hemocyanin (KLH)-conjugate (20) of the ABCDE-ring fragment of the Pacific ciguatoxins, CTX1B (1) and 54-deoxyCTX1B (4). We succeeded in producing a monoclonal antibody (3G8) against the left wings of these ciguatoxins by immunizing mice with the hapten-KLH conjugate (20) as the synthetic antigen. The most promising mAb, 3G8, does not cross-react with other related marine toxins. Sandwich enzyme-linked immunosorbent assay (ELISA) utilizing 3G8 and the previously prepared monoclonal antibody (8H4) enabled us to detect 1 specifically at less than 0.28 ng/mL. Copyright © 2012 Elsevier Ltd. All rights reserved.

  1. Broadly Applicable Strategy for the Fluorescence Based Detection and Differentiation of Glutathione and Cysteine/Homocysteine: Demonstration in Vitro and in Vivo.

    Science.gov (United States)

    Chen, Wenqiang; Luo, Hongchen; Liu, Xingjiang; Foley, James W; Song, Xiangzhi

    2016-04-05

    Glutathione (GSH), cysteine (Cys), and homocysteine (Hcy) are small biomolecular thiols that are present in all cells and extracellular fluids of healthy mammals. It is well-known that each plays a separate, critically important role in human physiology and that abnormal levels of each are predictive of a variety of different disease states. Although a number of fluorescence-based methods have been developed that can detect biomolecules that contain sulfhydryl moieties, few are able to differentiate between GSH and Cys/Hcy. In this report, we demonstrate a broadly applicable approach for the design of fluorescent probes that can achieve this goal. The strategy we employ is to conjugate a fluorescence-quenching 7-nitro-2,1,3-benzoxadiazole (NBD) moiety to a selected fluorophore (Dye) through a sulfhydryl-labile ether linkage to afford nonfluorescent NBD-O-Dye. In the presence of GSH or Cys/Hcy, the ether bond is cleaved with the concomitant generation of both a nonfluorescent NBD-S-R derivative and a fluorescent dye having a characteristic intense emission band (B1). In the special case of Cys/Hcy, the NBD-S-Cys/Hcy cleavage product can undergo a further, rapid, intramolecular Smiles rearrangement to form a new, highly fluorescent NBD-N-Cys/Hcy compound (band B2); because of geometrical constraints, the GSH derived NBD-S-GSH derivative cannot undergo a Smiles rearrangement. Thus, the presence of a single B1 or double B1 + B2 signature can be used to detect and differentiate GSH from Cys/Hcy, respectively. We demonstrate the broad applicability of our approach by including in our studies members of the Flavone, Bodipy, and Coumarin dye families. Particularly, single excitation wavelength could be applied for the probe NBD-OF in the detection of GSH over Cys/Hcy in both aqueous solution and living cells.

  2. Substantial prevalence of microdeletions of the Y-chromosome in infertile men with idiopathic azoospermia and oligozoospermia detected using a sequence-tagged site-based mapping strategy

    Energy Technology Data Exchange (ETDEWEB)

    Najmabadi, H.; Huang, V.; Bhasin, D. [Drew Univ. of Medicine and Science, Los Angeles, CA (United States)] [and others

    1996-04-01

    Genes on the long arm of Y (Yq), particularly within interval 6, are believed to play a critical role in human spermatogenesis. Cytogenetically detectable deletions of this region are associated with azoospermia in men, but are relatively uncommon. The objective of this study was to validate a sequence-tagged site (STS)-mapping strategy for the detection of Yq microdeletions and to use this method to determine the proportion of men with idiopathic azoospermia or severe oligozoospermia who carry microdeletions in Yq. STS mapping of a sufficiently large sample of infertile men should also help further localize the putative gene(s) involved in the pathogenesis of male infertility. Genomic DNA was extracted from peripheral leukocytes of 16 normal fertile men, 7 normal fertile women, 60 infertile men, and 15 patients with the X-linked disorder, ichthyosis. PCR primers were synthesized for 26 STSs that span Yq interval 6. None of the 16 normal men of known fertility had microdeletions. Seven normal fertile women failed to amplify any of the 26 STSs, providing evidence of their Y specificity. No microdeletions were detected in any of the 15 patients with ichthyosis. Of the 60 infertile men typed with 26 STSs, 11 (18%; 10 azoospermic and 1 oligozoospermic) failed to amplify 1 or more STS. Interestingly, 4 of the 11 patients had microdeletions in a region that is outside the Yq region from which the DAZ (deleted in azoospermia gene region) gene was cloned. In an additional 3 patients, microdeletions were present both inside and outside the DAZ region. The physical locations of these microdeletions provide further support for the concept that a gene(s) on Yq deletion interval 6 plays an important role in spermatogenesis. The presence of deletions that do not overlap with the DAZ region suggests that genes other than the DAZ gene may also be implicated in the pathogenesis of some subsets of male infertility. 48 refs., 2 figs., 2 tabs.

  3. Ultrasensitive electrochemical immunosensor for PSA biomarker detection in prostate cancer cells using gold nanoparticles/PAMAM dendrimer loaded with enzyme linked aptamer as integrated triple signal amplification strategy.

    Science.gov (United States)

    Kavosi, Begard; Salimi, Abdollah; Hallaj, Rahman; Moradi, Fathollah

    2015-12-15

    In the present study, a triple signal amplification strategy was developed for ultrasensitive immunosensing of prostate-specific antigen (PSA) tumor marker. The proposed system was achieved by modification of glassy carbon electrode with graphene oxide/chitosan film and covalently attached of monoclonal PSA antibody and thionine as redox probe onto the modified electrode surface. Then, immunosensing was completed using sandwich-type immunoreaction of the PSA-antigen between anti-PSA immobilized on the graphene/chitosan interface and PSA-aptamer. For improve the sensitivity, polyamidoamine dendrimer-encapsulated gold nanoparticles (AuNPs-PAMAM) was used for covalent attachment of PSA-aptamer and HRP linked aptamer (Au-PAMA/aptamer-HRP) as electrochemical label in the sandwich format and electrocatalytic reduction of H2O2 in the presence of enzymatically oxidized thionine was measured. Under optimized condition, the obtained detection limit and linear concentration range were 10 fg ml(-1)(S/N=3) and 0.1 pg ml(-1) to 90 ngml(-1) respectively, using differential pulse voltammetry as measuring technique. In addition, electrochemical impedance spectroscopy (EIS) was used as simple, rapid, low cost label free analytical technique for PSA measurement with detection limit of 5 pg ml(-1) at concentration range up to 35 ng ml(-1). Finally, the immunosensor is used to PSA detection in human serum and prostate tissue samples and the obtained result is well agreed with the values obtained by the standard ELISA method. The obtained results indicate the proposed immunosensor can be used for monitor the differences in PSA concentration in cancer tissue samples which holds great promise in clinical screening of cancer biomarkers. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. An electrochemical aptasensor for detection of IFN-γ using graphene and a dual signal amplification strategy based on the exonuclease-mediated surface-initiated enzymatic polymerization.

    Science.gov (United States)

    Liu, Chang; Xiang, Guiming; Jiang, Dongneng; Liu, Linlin; Liu, Fei; Luo, Fukang; Pu, Xiaoyun

    2015-11-21

    Tuberculosis is one of the major health problems in the world. The cytokine interferon γ (IFN-γ) is associated with the disease-specific immune responses and is used as a tuberculosis diagnosis marker. In this study, a novel electrochemical aptasensor was developed for IFN-γ detection based on the exonuclease-catalyzed target recycling and the TdT-mediated cascade signal amplification. To construct the aptasensor, a previously hybridized double-stranded DNA (capture probe hybridization with a complementary IFN-γ binding aptamer) was immobilized on a gold nanoparticle-graphene (Au-Gra) nanohybrid film-modified electrode. In the presence of IFN-γ, the formation of an aptamer-IFN-γ complex leads to the liberation of the aptamer from the double-stranded DNA (dsDNA). Using exonuclease, the aptamer was selectively digested, and IFN-γ was released for the target recycling. A large amount of single-stranded capture probes formed and led to the hybridization with signal probe-labelled Au@Fe3O4. Then, the labelled signal probe sequences were catalyzed at the 3'-OH group by terminal deoxynucleotidyl transferase (TdT) to form a long single-stranded DNA structure. As a result, the electron mediator hexaammineruthenium(III) chloride ([Ru(NH3)6](3+)) electrostatically adsorbed onto DNA producing a strong electrochemical signal which can be used to quantitatively measure the IFN-γ levels. With the conducting nanomaterial Au-Gra as a substrate and the target recycling-based surface-initiated enzymatic polymerization-mediated signal amplification strategy, the proposed aptasensor displayed a broad linearity with a low detection limit of 0.003 ng mL(-1). Moreover, the resulting aptasensor exhibited good specificity, acceptable reproducibility and stability, which makes this method versatile and suitable for detecting IFN-γ and other biomolecules.

  5. Disulfide-induced self-assembled targets: A novel strategy for the label free colorimetric detection of DNAs/RNAs via unmodified gold nanoparticles

    Science.gov (United States)

    Shokri, Ehsan; Hosseini, Morteza; Davari, Mehdi D.; Ganjali, Mohammad R.; Peppelenbosch, Maikel P.; Rezaee, Farhad

    2017-04-01

    A modified non-cross-linking gold-nanoparticles (Au-NPs) aggregation strategy has been developed for the label free colorimetric detection of DNAs/RNAs based on self-assembling target species in the presence of thiolated probes. Two complementary thiol- modified probes, each of which specifically binds at one half of the target introduced SH groups at both ends of dsDNA. Continuous disulfide bond formation at 3‧ and 5‧ terminals of targets leads to the self-assembly of dsDNAs into the sulfur- rich and flexible products with different lengths. These products have a high affinity for the surface of Au-NPs and efficiently protect the surface from salt induced aggregation. To evaluate the assay efficacy, a small part of the citrus tristeza virus (CTV) genome was targeted, leading to a detection limit of about 5 × 10-9 mol.L-1 over a linear ranged from 20 × 10-9 to 10 × 10-7 mol.L-1. This approach also exhibits good reproducibility and recovery levels in the presence of plant total RNA or human plasma total circulating RNA extracts. Self-assembled targets can be then sensitively distinguished from non-assembled or mismatched targets after gel electrophoresis. The disulfide reaction method and integrating self-assembled DNAs/RNAs targets with bare AuNPs as a sensitive indicator provide us a powerful and simple visual detection tool for a wide range of applications.

  6. A Novel Strategy for Detection and Enumeration of Circulating Rare Cell Populations in Metastatic Cancer Patients Using Automated Microfluidic Filtration and Multiplex Immunoassay.

    Science.gov (United States)

    Magbanua, Mark Jesus M; Pugia, Michael; Lee, Jin Sun; Jabon, Marc; Wang, Victoria; Gubens, Matthew; Marfurt, Karen; Pence, Julia; Sidhu, Harwinder; Uzgiris, Arejas; Rugo, Hope S; Park, John W

    2015-01-01

    Size selection via filtration offers an antigen-independent approach for the enrichment of rare cell populations in blood of cancer patients. We evaluated the performance of a novel approach for multiplex rare cell detection in blood samples from metastatic breast (n = 19) and lung cancer patients (n = 21), and healthy controls (n = 30) using an automated microfluidic filtration and multiplex immunoassay strategy. Captured cells were enumerated after sequential staining for specific markers to identify circulating tumor cells (CTCs), circulating mesenchymal cells (CMCs), putative circulating stem cells (CSCs), and circulating endothelial cells (CECs). Preclinical validation experiments using cancer cells spiked into healthy blood demonstrated high recovery rate (mean = 85%) and reproducibility of the assay. In clinical studies, CTCs and CMCs were detected in 35% and 58% of cancer patients, respectively, and were largely absent from healthy controls (3%, p = 0.001). Mean levels of CTCs were significantly higher in breast than in lung cancer patients (p = 0.03). Fifty-three percent (53%) of cancer patients harbored putative CSCs, while none were detectable in healthy controls (p<0.0001). In contrast, CECs were observed in both cancer and control groups. Direct comparison of CellSearch® vs. our microfluidic filter method revealed moderate correlation (R2 = 0.46, kappa = 0.47). Serial blood analysis in breast cancer patients demonstrated the feasibility of monitoring circulating rare cell populations over time. Simultaneous assessment of CTCs, CMCs, CSCs and CECs may provide new tools to study mechanisms of disease progression and treatment response/resistance.

  7. A Novel Strategy for Detection and Enumeration of Circulating Rare Cell Populations in Metastatic Cancer Patients Using Automated Microfluidic Filtration and Multiplex Immunoassay.

    Directory of Open Access Journals (Sweden)

    Mark Jesus M Magbanua

    Full Text Available Size selection via filtration offers an antigen-independent approach for the enrichment of rare cell populations in blood of cancer patients. We evaluated the performance of a novel approach for multiplex rare cell detection in blood samples from metastatic breast (n = 19 and lung cancer patients (n = 21, and healthy controls (n = 30 using an automated microfluidic filtration and multiplex immunoassay strategy. Captured cells were enumerated after sequential staining for specific markers to identify circulating tumor cells (CTCs, circulating mesenchymal cells (CMCs, putative circulating stem cells (CSCs, and circulating endothelial cells (CECs. Preclinical validation experiments using cancer cells spiked into healthy blood demonstrated high recovery rate (mean = 85% and reproducibility of the assay. In clinical studies, CTCs and CMCs were detected in 35% and 58% of cancer patients, respectively, and were largely absent from healthy controls (3%, p = 0.001. Mean levels of CTCs were significantly higher in breast than in lung cancer patients (p = 0.03. Fifty-three percent (53% of cancer patients harbored putative CSCs, while none were detectable in healthy controls (p<0.0001. In contrast, CECs were observed in both cancer and control groups. Direct comparison of CellSearch® vs. our microfluidic filter method revealed moderate correlation (R2 = 0.46, kappa = 0.47. Serial blood analysis in breast cancer patients demonstrated the feasibility of monitoring circulating rare cell populations over time. Simultaneous assessment of CTCs, CMCs, CSCs and CECs may provide new tools to study mechanisms of disease progression and treatment response/resistance.

  8. Ultraviolet radiation modelling from ground-based and satellite measurements on Reunion Island, southern tropics

    Directory of Open Access Journals (Sweden)

    K. Lamy

    2018-01-01

    Full Text Available Surface ultraviolet radiation (SUR is not an increasing concern after the implementation of the Montreal Protocol and the recovery of the ozone layer Morgenstern et al.(2008. However, large uncertainties remain in the prediction of future changes of SUR Bais et al.(2015. Several studies pointed out that UV-B impacts the biosphere Erickson et al.(2015, especially the aquatic system, which plays a central part in the biogeochemical cycle Hader et al.(2007. It can affect phytoplankton productivity Smith and Cullen(1995. This influence can result in either positive or negative feedback on climate (Zepp et al., 2007. Global circulation model simulations predict an acceleration of the Brewer-Dobson circulation over the next century (Butchart, 2014, which would lead to a decrease in ozone levels in the tropics and an enhancement at higher latitudes (Hegglin and Shepherd, 2009. Reunion Island is located in the tropics (21° S, 55° E, in a part of the world where the amount of ozone in the ozone column is naturally low. In addition, this island is mountainous and the marine atmosphere is often clean with low aerosol concentrations. Thus, measurements show much higher SUR than at other sites at the same latitude or at midlatitudes. Ground-based measurements of SUR have been taken on Reunion Island by a Bentham DTMc300 spectroradiometer since 2009. This instrument is affiliated with the Network for the Detection of Atmospheric Composition Change (NDACC. In order to quantify the future evolution of SUR in the tropics, it is necessary to validate a model against present observations. This study is designed to be a preliminary parametric and sensitivity study of SUR modelling in the tropics. We developed a local parameterisation using the Tropospheric Ultraviolet and Visible Model (TUV; Madronich, 1993 and compared the output of TUV to multiple years of Bentham spectral measurements. This comparison started in early 2009 and continued until 2016

  9. Ultraviolet radiation modelling from ground-based and satellite measurements on Reunion Island, southern tropics

    Science.gov (United States)

    Lamy, Kévin; Portafaix, Thierry; Brogniez, Colette; Godin-Beekmann, Sophie; Bencherif, Hassan; Morel, Béatrice; Pazmino, Andrea; Metzger, Jean Marc; Auriol, Frédérique; Deroo, Christine; Duflot, Valentin; Goloub, Philippe; Long, Charles N.

    2018-01-01

    Surface ultraviolet radiation (SUR) is not an increasing concern after the implementation of the Montreal Protocol and the recovery of the ozone layer (Morgenstern et al., 2008). However, large uncertainties remain in the prediction of future changes of SUR (Bais et al., 2015). Several studies pointed out that UV-B impacts the biosphere (Erickson et al., 2015), especially the aquatic system, which plays a central part in the biogeochemical cycle (Hader et al., 2007). It can affect phytoplankton productivity (Smith and Cullen, 1995). This influence can result in either positive or negative feedback on climate (Zepp et al., 2007). Global circulation model simulations predict an acceleration of the Brewer-Dobson circulation over the next century (Butchart, 2014), which would lead to a decrease in ozone levels in the tropics and an enhancement at higher latitudes (Hegglin and Shepherd, 2009). Reunion Island is located in the tropics (21° S, 55° E), in a part of the world where the amount of ozone in the ozone column is naturally low. In addition, this island is mountainous and the marine atmosphere is often clean with low aerosol concentrations. Thus, measurements show much higher SUR than at other sites at the same latitude or at midlatitudes. Ground-based measurements of SUR have been taken on Reunion Island by a Bentham DTMc300 spectroradiometer since 2009. This instrument is affiliated with the Network for the Detection of Atmospheric Composition Change (NDACC). In order to quantify the future evolution of SUR in the tropics, it is necessary to validate a model against present observations. This study is designed to be a preliminary parametric and sensitivity study of SUR modelling in the tropics. We developed a local parameterisation using the Tropospheric Ultraviolet and Visible Model (TUV; Madronich, 1993) and compared the output of TUV to multiple years of Bentham spectral measurements. This comparison started in early 2009 and continued until 2016. Only

  10. Ground-based monitoring of solar radiation in Moldova

    Science.gov (United States)

    Aculinin, Alexandr; Smicov, Vladimir

    2010-05-01

    Integrated measurements of solar radiation in Kishinev, Moldova have been started by Atmospheric Research Group (ARG) at the Institute of Applied Physics from 2003. Direct, diffuse and total components of solar and atmospheric long-wave radiation are measured by using of the radiometric complex at the ground-based solar radiation monitoring station. Measurements are fulfilled at the stationary and moving platforms equipped with the set of 9 broadband solar radiation sensors overlapping wavelength range from UV-B to IR. Detailed description of the station can be found at the site http://arg.phys.asm.md. Ground station is placed in an urban environment of Kishinev city (47.00N; 28.56E). Summary of observation data acquired at the station in the course of short-term period from 2004 to 2009 are presented below. Solar radiation measurements were fulfilled by using CM11(280-3000 nm) and CH1 sensors (Kipp&Zonen). In the course of a year maximum and minimum of monthly sums of total radiation was ~706.4 MJm-2 in June and ~82.1MJm-2 in December, respectively. Monthly sums of direct solar radiation (on horizontal plane) show the maximum and minimum values of the order ~456.9 MJm-2 in July and ~25.5MJm-2 in December, respectively. In an average, within a year should be marked the predominance of direct radiation over the scattered radiation, 51% and 49%, respectively. In the course of a year, the percentage contribution of the direct radiation into the total radiation is ~55-65% from May to September. In the remaining months, the percentage contribution decreases and takes the minimum value of ~ 28% in December. In an average, annual sum of total solar radiation is ~4679.9 MJm-2. For the period from April to September accounts for ~76% of the annual amount of total radiation. Annual sum of sunshine duration accounts for ~2149 hours, which is of ~ 48% from the possible sunshine duration. In an average, within a year maximum and minimum of sunshine duration is ~ 304 hours in

  11. Ground-based Space Weather Monitoring with LOFAR

    Science.gov (United States)

    Wise, Michael; van Haarlem, Michiel; Lawrence, Gareth; Reid, Simon; Bos, Andre; Rawlings, Steve; Salvini, Stef; Mitchell, Cathryn; Soleimani, Manuch; Amado, Sergio; Teresa, Vital

    As one of the first of a new generation of radio instruments, the International LOFAR Telescope (ILT) will provide a number of unique and novel capabilities for the astronomical community. These include remote configuration and operation, dynamic real-time processing and system response, and the ability to provide multiple simultaneous streams of data to a community whose scientific interests run the gamut from lighting in the atmospheres of distant planets to the origins of the universe itself. The LOFAR (LOw Frequency ARray) system is optimized for a frequency range from 30-240 MHz and consists of multiple antenna fields spread across Europe. In the Netherlands, a total 36 LOFAR stations are nearing completion with an initial 8 international stations currently being deployed in Germany, France, Sweden, and the UK. Digital beam-forming techniques make the LOFAR system agile and allow for rapid repointing of the telescope as well as the potential for multiple simultaneous observations. With its dense core array and long interferometric baselines, LOFAR has the potential to achieve unparalleled sensitivity and spatial resolution in the low frequency radio regime. LOFAR will also be one of the first radio observatories to feature automated processing pipelines to deliver fully calibrated science products to its user community. As we discuss in this presentation, the same capabilities that make LOFAR a powerful tool for radio astronomy also provide an excellent platform upon which to build a ground-based monitoring system for space weather events. For example, the ability to monitor Solar activity in near real-time is one of the key scientific capabilities being developed for LOFAR. With only a fraction of its total observing capacity, LOFAR will be able to provide continuous monitoring of the Solar spectrum over the entire 10-240 MHz band down to microsecond timescales. Autonomous routines will scan these incoming spectral data for evidence of Solar flares and be

  12. Estimation of High-Frequency Earth-Space Radio Wave Signals via Ground-Based Polarimetric Radar Observations

    Science.gov (United States)

    Bolen, Steve; Chandrasekar, V.

    2002-01-01

    Expanding human presence in space, and enabling the commercialization of this frontier, is part of the strategic goals for NASA's Human Exploration and Development of Space (HEDS) enterprise. Future near-Earth and planetary missions will support the use of high-frequency Earth-space communication systems. Additionally, increased commercial demand on low-frequency Earth-space links in the S- and C-band spectra have led to increased interest in the use of higher frequencies in regions like Ku and Ka-band. Attenuation of high-frequency signals, due to a precipitating medium, can be quite severe and can cause considerable disruptions in a communications link that traverses such a medium. Previously, ground radar measurements were made along the Earth-space path and compared to satellite beacon data that was transmitted to a ground station. In this paper, quantitative estimation of the attenuation along the propagation path is made via inter-comparisons of radar data taken from the Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (PR) and ground-based polarimetric radar observations. Theoretical relationships between the expected specific attenuation (k) of spaceborne measurements with ground-based measurements of reflectivity (Zh) and differential propagation phase shift (Kdp) are developed for various hydrometeors that could be present along the propagation path, which are used to estimate the two-way path-integrated attenuation (PIA) on the PR return echo. Resolution volume matching and alignment of the radar systems is performed, and a direct comparison of PR return echo with ground radar attenuation estimates is made directly on a beam-by-beam basis. The technique is validated using data collected from the TExas and Florida UNderflights (TEFLUN-B) experiment and the TRMM large Biosphere-Atmosphere experiment in Amazonia (LBA) campaign. Attenuation estimation derived from this method can be used for strategiC planning of communication systems for

  13. Quantifying the effect of riming on snowfall using ground-based observations

    Science.gov (United States)

    Moisseev, Dmitri; von Lerber, Annakaisa; Tiira, Jussi

    2017-04-01

    Ground-based observations of ice particle size distribution and ensemble mean density are used to quantify the effect of riming on snowfall. The rime mass fraction is derived from these measurements by following the approach that is used in a single ice-phase category microphysical scheme proposed for the use in numerical weather prediction models. One of the characteristics of the proposed scheme is that the prefactor of a power law relation that links mass and size of ice particles is determined by the rime mass fraction, while the exponent does not change. To derive the rime mass fraction, a mass-dimensional relation representative of unrimed snow is also determined. To check the validity of the proposed retrieval method, the derived rime mass fraction is converted to the effective liquid water path that is compared to microwave radiometer observations. Since dual-polarization radar observations are often used to detect riming, the impact of riming on dual-polarization radar variables is studied for differential reflectivity measurements. It is shown that the relation between rime mass fraction and differential reflectivity is ambiguous, other factors such as change in median volume diameter need also be considered. Given the current interest on sensitivity of precipitation to aerosol pollution, which could inhibit riming, the importance of riming for surface snow accumulation is investigated. It is found that riming is responsible for 5% to 40% of snowfall mass. The study is based on data collected at the University of Helsinki field station in Hyytiälä during U.S. Department of Energy Biogenic Aerosols Effects on Clouds and Climate (BAECC) field campaign and the winter 2014/2015. In total 22 winter storms were analyzed, and detailed analysis of two events is presented to illustrate the study.

  14. Ground-based solar radio observations of the August 1972 events

    International Nuclear Information System (INIS)

    Bhonsle, R.V.; Degaonkar, S.S.; Alurkar, S.K.

    1976-01-01

    Ground-based observations of the variable solar radio emission ranging from few millimetres to decametres have been used here as a diagnostic tool to gain coherent phenomenological understanding of the great 2, 4 and 7 August, 1972 solar events in terms of dominant physical processes like generation and propagation of shock waves in the solar atmosphere, particle acceleration and trapping. Four major flares are selected for detailed analysis on the basis of their ability to produce energetic protons, shock waves, polar cap absorptions (PCA) and sudden commencement (SC) geomagnetic storms. A comparative study of their radio characteristics is made. Evidence is seen for the pulsations during microwave bursts by the mechanism similar to that proposed by McLean et al. (1971), to explain the pulsations in the metre wavelength continuum radiation. It is suggested that the multiple peaks observed in some microwave bursts may be attributable to individual flares occurring sequentially due to a single initiating flare. Attempts have been made to establish identification of Type II bursts with the interplanetary shock waves and SC geomagnetic storms. Furthermore, it is suggested that it is the mass behind the shock front which is the deciding factor for the detection of shock waves in the interplantary space. It appears that more work is necessary in order to identify which of the three moving Type IV bursts (Wild and Smerd, 1972), namely, advancing shock front, expanding magnetic arch and ejected plasma blob serves as the piston-driver behind the interplanetary shocks. The existing criteria for proton flare prediction have been summarized and two new criteria have been proposed. (Auth.)

  15. Characterizing GEO Titan IIIC Transtage Fragmentations using Ground-Based and Telescopic Measurements

    Science.gov (United States)

    Cowardin, Heather; Anz-Meador, Phillip; Reyes, Jacqueline A.

    2017-01-01

    In a continued effort to better characterize the geosynchronous orbit (GEO) environment, NASA's Orbital Debris Program Office (ODPO) utilizes various ground-based optical assets to acquire photometric and spectral data of known debris associated with fragmentations in or near GEO. The Titan IIIC Transtage upper stage is known to have fragmented four times. Two of the four fragmentations were in GEO while the Transtage fragmented a third time in GEO transfer orbit. The forth fragmentation occurred in low Earth orbit. To better assess and characterize these fragmentations, the NASA ODPO acquired a Titan Transtage test and display article previously in the custody of the 309th Aerospace Maintenance and Regeneration Group (AMARG) in Tucson, Arizona. After initial inspections at AMARG demonstrated that it was of sufficient fidelity to be of interest, the test article was brought to NASA Johnson Space Center (JSC) to continue material analysis and historical documentation. The Transtage has undergone two separate spectral measurement campaigns to characterize the reflectance spectroscopy of historical aerospace materials. These data have been incorporated into the NASA Spectral Database, with the goal of using telescopic data comparisons for potential material identification. A Light Detection and Ranging (LIDAR) system scan also has been completed and a scale model has been created for use in the Optical Measurement Center (OMC) for photometric analysis of an intact Transtage, including bidirectional reflectance distribution function (BRDF) measurements. An historical overview of the Titan IIIC Transtage, the current analysis that has been done to date, and the future work to be completed in support of characterizing the GEO and near GEO orbital debris environment will be discussed in the subsequent presentation.

  16. Ground-Based Measurements of the 2014–2015 Holuhraun Volcanic Cloud (Iceland

    Directory of Open Access Journals (Sweden)

    Melissa A. Pfeffer

    2018-01-01

    Full Text Available The 2014–2015 Bárðarbunga fissure eruption at Holuhraun in central Iceland was distinguished by the high emission of gases, in total 9.6 Mt SO2, with almost no tephra. This work collates all ground-based measurements of this extraordinary eruption cloud made under particularly challenging conditions: remote location, optically dense cloud with high SO2 column amounts, low UV intensity, frequent clouds and precipitation, an extensive and hot lava field, developing ramparts, and high-latitude winter conditions. Semi-continuous measurements of SO2 flux with three scanning DOAS instruments were augmented by car traverses along the ring-road and along the lava. The ratios of other gases/SO2 were measured by OP-FTIR, MultiGAS, and filter packs. Ratios of SO2/HCl = 30–110 and SO2/HF = 30–130 show a halogen-poor eruption cloud. Scientists on-site reported extremely minor tephra production during the eruption. OPC and filter packs showed low particle concentrations similar to non-eruption cloud conditions. Three weather radars detected a droplet-rich eruption cloud. Top of eruption cloud heights of 0.3–5.5 km agl were measured with ground- and aircraft-based visual observations, web camera and NicAIR II infrared images, triangulation of scanning DOAS instruments, and the location of SO2 peaks measured by DOAS traverses. Cloud height and emission rate measurements were critical for initializing gas dispersal simulations for hazard forecasting.

  17. Ground-based remote sensing of tropospheric water vapour isotopologues within the project MUSICA

    Science.gov (United States)

    Schneider, M.; Barthlott, S.; Hase, F.; González, Y.; Yoshimura, K.; García, O. E.; Sepúlveda, E.; Gomez-Pelaez, A.; Gisi, M.; Kohlhepp, R.; Dohe, S.; Blumenstock, T.; Wiegele, A.; Christner, E.; Strong, K.; Weaver, D.; Palm, M.; Deutscher, N. M.; Warneke, T.; Notholt, J.; Lejeune, B.; Demoulin, P.; Jones, N.; Griffith, D. W. T.; Smale, D.; Robinson, J.

    2012-12-01

    Within the project MUSICA (MUlti-platform remote Sensing of Isotopologues for investigating the Cycle of Atmospheric water), long-term tropospheric water vapour isotopologue data records are provided for ten globally distributed ground-based mid-infrared remote sensing stations of the NDACC (Network for the Detection of Atmospheric Composition Change). We present a new method allowing for an extensive and straightforward characterisation of the complex nature of such isotopologue remote sensing datasets. We demonstrate that the MUSICA humidity profiles are representative for most of the troposphere with a vertical resolution ranging from about 2 km (in the lower troposphere) to 8 km (in the upper troposphere) and with an estimated precision of better than 10%. We find that the sensitivity with respect to the isotopologue composition is limited to the lower and middle troposphere, whereby we estimate a precision of about 30‰ for the ratio between the two isotopologues HD16O and H216O. The measurement noise, the applied atmospheric temperature profiles, the uncertainty in the spectral baseline, and the cross-dependence on humidity are the leading error sources. We introduce an a posteriori correction method of the cross-dependence on humidity, and we recommend applying it to isotopologue ratio remote sensing datasets in general. In addition, we present mid-infrared CO2 retrievals and use them for demonstrating the MUSICA network-wide data consistency. In order to indicate the potential of long-term isotopologue remote sensing data if provided with a well-documented quality, we present a climatology and compare it to simulations of an isotope incorporated AGCM (Atmospheric General Circulation Model). We identify differences in the multi-year mean and seasonal cycles that significantly exceed the estimated errors, thereby indicating deficits in the modeled atmospheric water cycle.

  18. Ground-based remote sensing of tropospheric water vapour isotopologues within the project MUSICA

    Directory of Open Access Journals (Sweden)

    M. Schneider

    2012-12-01

    Full Text Available Within the project MUSICA (MUlti-platform remote Sensing of Isotopologues for investigating the Cycle of Atmospheric water, long-term tropospheric water vapour isotopologue data records are provided for ten globally distributed ground-based mid-infrared remote sensing stations of the NDACC (Network for the Detection of Atmospheric Composition Change. We present a new method allowing for an extensive and straightforward characterisation of the complex nature of such isotopologue remote sensing datasets. We demonstrate that the MUSICA humidity profiles are representative for most of the troposphere with a vertical resolution ranging from about 2 km (in the lower troposphere to 8 km (in the upper troposphere and with an estimated precision of better than 10%. We find that the sensitivity with respect to the isotopologue composition is limited to the lower and middle troposphere, whereby we estimate a precision of about 30‰ for the ratio between the two isotopologues HD16O and H216O. The measurement noise, the applied atmospheric temperature profiles, the uncertainty in the spectral baseline, and the cross-dependence on humidity are the leading error sources. We introduce an a posteriori correction method of the cross-dependence on humidity, and we recommend applying it to isotopologue ratio remote sensing datasets in general. In addition, we present mid-infrared CO2 retrievals and use them for demonstrating the MUSICA network-wide data consistency. In order to indicate the potential of long-term isotopologue remote sensing data if provided with a well-documented quality, we present a climatology and compare it to simulations of an isotope incorporated AGCM (Atmospheric General Circulation Model. We identify differences in the multi-year mean and seasonal cycles that significantly exceed the estimated errors, thereby indicating deficits in the modeled atmospheric water cycle.

  19. Validation of stratospheric temperature profiles from a ground-based microwave radiometer with other techniques

    Science.gov (United States)

    Navas, Francisco; Kämpfer, Niklaus; Haefele, Alexander; Keckhut, Philippe; Hauchecorne, Alain

    2016-04-01

    Vertical profiles of atmospheric temperature trends has become recognized as an important indicator of climate change, because different climate forcing mechanisms exhibit distinct vertical warming and cooling patterns. For example, the cooling of the stratosphere is an indicator for climate change as it provides evidence of natural and anthropogenic climate forcing just like surface warming. Despite its importance, our understanding of the observed stratospheric temperature trend and our ability to test simulations of the stratospheric response to emissions of greenhouse gases and ozone depleting substances remains limited. One of the main reason is because stratospheric long-term datasets are sparse and obtained trends differ from one another. Different techniques allow to measure stratospheric temperature profiles as radiosonde, lidar or satellite. The main advantage of microwave radiometers against these other instruments is a high temporal resolution with a reasonable good spatial resolution. Moreover, the measurement at a fixed location allows to observe local atmospheric dynamics over a long time period, which is crucial for climate research. This study presents an evaluation of the stratospheric temperature profiles from a newly ground-based microwave temperature radiometer (TEMPERA) which has been built and designed at the University of Bern. The measurements from TEMPERA are compared with the ones from other different techniques such as in-situ (radiosondes), active remote sensing (lidar) and passive remote sensing on board of Aura satellite (MLS) measurements. In addition a statistical analysis of the stratospheric temperature obtained from TEMPERA measurements during four years of data has been performed. This analysis evidenced the capability of TEMPERA radiometer to monitor the temperature in the stratosphere for a long-term. The detection of some singular sudden stratospheric warming (SSW) during the analyzed period shows the necessity of these

  20. Ground-Based Global Navigation Satellite System (GNSS) GLONASS Broadcast Ephemeris Data (hourly files) from NASA CDDIS

    Data.gov (United States)

    National Aeronautics and Space Administration — This dataset consists of ground-based Global Navigation Satellite System (GNSS) GLObal NAvigation Satellite System (GLONASS) Broadcast Ephemeris Data (hourly files)...

  1. Metrology of ground-based satellite validation: co-location mismatch and smoothing issues of total ozone comparisons

    Directory of Open Access Journals (Sweden)

    T. Verhoelst

    2015-12-01

    Full Text Available Comparisons with ground-based correlative measurements constitute a key component in the validation of satellite data on atmospheric composition. The error budget of these comparisons contains not only the measurement errors but also several terms related to differences in sampling and smoothing of the inhomogeneous and variable atmospheric field. A versatile system for Observing System Simulation Experiments (OSSEs, named OSSSMOSE, is used here to quantify these terms. Based on the application of pragmatic observation operators onto high-resolution atmospheric fields, it allows a simulation of each individual measurement, and consequently, also of the differences to be expected from spatial and temporal field variations between both measurements making up a comparison pair. As a topical case study, the system is used to evaluate the error budget of total ozone column (TOC comparisons between GOME-type direct fitting (GODFITv3 satellite retrievals from GOME/ERS2, SCIAMACHY/Envisat, and GOME-2/MetOp-A, and ground-based direct-sun and zenith–sky reference measurements such as those from Dobsons, Brewers, and zenith-scattered light (ZSL-DOAS instruments, respectively. In particular, the focus is placed on the GODFITv3 reprocessed GOME-2A data record vs. the ground-based instruments contributing to the Network for the Detection of Atmospheric Composition Change (NDACC. The simulations are found to reproduce the actual measurements almost to within the measurement uncertainties, confirming that the OSSE approach and its technical implementation are appropriate. This work reveals that many features of the comparison spread and median difference can be understood as due to metrological differences, even when using strict co-location criteria. In particular, sampling difference errors exceed measurement uncertainties regularly at most mid- and high-latitude stations, with values up to 10 % and more in extreme cases. Smoothing difference errors only

  2. Ground-Based Observations of Terrestrial Gamma Ray Flashes Associated with Downward-Directed Lightning Leaders

    Science.gov (United States)

    Belz, J.; Abbasi, R.; Krehbiel, P. R.; LeVon, R.; Remington, J.; Rison, W.; Thomas, R. J.

    2017-12-01

    Terrestrial Gamma Flashes (TGFs) have been observed in satellite-borne gamma ray detectors for several decades, starting with the BATSE instrument on the Compton Gamma-Ray observatory in 1994. TGFs consist of bursts of upwards of 1018 primary gamma rays, with a duration of up to a few milliseconds, originating in the Earth's atmosphere. More recent observations have shown that satellite-observed TGFs are generated in upward-propagating negative leaders of intracloud lightning, suggesting that they may be sensitive to the processes responsible for the initial lightning breakdown. Here, we present the first evidence that TGFs are also produced at the beginning of negative cloud-to-ground flashes, and that they may provide a new window through which ground-based observatories may contribute to understanding the breakdown process. The Telescope Array Surface Detector (TASD) is a 700 square kilometer cosmic ray observatory, an array of 507 3m2 scintillators on a 1.2 km grid. The array is triggered and read out when at least three adjacent detectors observe activity within an 8 μs window. Following the observation of bursts of anomalous TASD triggers, lasting a few hundred microseconds and correlated with local lightning activity, a Lightning Mapping Array (LMA) and slow electric field antenna were installed at the TASD site in order to study the effect. From data obtained between 2014 and 2016, correlated observations were obtained for ten -CG flashes. In 9 out of 10 cases, bursts of up to five anomalous triggers were detected during the first ms of the flash, as negative breakdown was descending into lower positive storm charge. The triggers occurred when the LMA-detected VHF radiation sources were at altitudes between 1.5 to 4.5 km AGL. The tenth flash was initiated by an unusually energetic leader that reached the ground in 2.5 ms and produced increasingly powerful triggers down to about 500 m AGL. While the TASD is not optimized for individual gamma ray detection

  3. BigBOSS: The Ground-Based Stage IV BAO Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Schlegel, David; Bebek, Chris; Heetderks, Henry; Ho, Shirley; Lampton, Michael; Levi, Michael; Mostek, Nick; Padmanabhan, Nikhil; Perlmutter, Saul; Roe, Natalie; Sholl, Michael; Smoot, George; White, Martin; Dey, Arjun; Abraham, Tony; Jannuzi, Buell; Joyce, Dick; Liang, Ming; Merrill, Mike; Olsen, Knut; Salim, Samir

    2009-04-01

    The BigBOSS experiment is a proposed DOE-NSF Stage IV ground-based dark energy experiment to study baryon acoustic oscillations (BAO) and the growth of structure with an all-sky galaxy redshift survey. The project is designed to unlock the mystery of dark energy using existing ground-based facilities operated by NOAO. A new 4000-fiber R=5000 spectrograph covering a 3-degree diameter field will measure BAO and redshift space distortions in the distribution of galaxies and hydrogen gas spanning redshifts from 0.2< z< 3.5. The Dark Energy Task Force figure of merit (DETF FoM) for this experiment is expected to be equal to that of a JDEM mission for BAO with the lower risk and cost typical of a ground-based experiment.

  4. Development of a real-time detection strategy for process monitoring during nuclear fuel reprocessing using the UREX+3a method

    International Nuclear Information System (INIS)

    Goddard, Braden; Charlton, William S.; McDeavitt, Sean M.

    2010-01-01

    Research highlights: → HPGe detectors are suitable for UREX+3a real-time spectroscopy. → HPGe N-type detectors may be suitable for a reprocessing facility. → Gamma ray self-shielding does not occur for pipe diameters less than 2 in. - Abstract: Reprocessing nuclear fuel is becoming more viable in the United States due to the anticipated increase in construction of nuclear power plants, the growing stockpile of existing used nuclear fuel, and a public desire to reduce the amount of this fuel. A new reprocessing facility will likely have state of the art controls and monitoring methods to safeguard special nuclear materials, as well as to provide real-time monitoring for process control. The focus of this research was to create a proof of concept to enable the development of a detection strategy that uses well established gamma and neutron measurement methods to characterize samples from the Uranium Extraction Plus 3a (UREX+3a) reprocessing method using a variety of detector types and measurement times. A facility that implemented real-time gamma detection equipment could improve product quality control and provide additional benefits, such as waste volume reduction. In addition to the spectral analyses, it was determined by Monte Carlo N Particle (MCNP) simulations that there is no noticeable self-shielding for internal pipe diameters less than 5.08 cm, indicating that no self-shielding correction factors are needed. Further, it was determined that High Purity Germanium (HPGe) N-type detectors have the high gamma ray energy resolution and neutron damage resistance that would be required in a reprocessing facility. Finally, the gamma ray spectra for the measured samples were simulated using MCNP and then the model was extended to predict the responses from an actual reprocessing scenario from UREX+3a applied to fuel that had a decay time of 3 years. The 3-year decayed fuel was more representative of commercially reprocessed fuel than the acquired UREX+3a

  5. Using ground-based geophysics to rapidly and accurately map sub-surface acidity

    Science.gov (United States)

    Wong, Vanessa; Triantafilis, John; Johnston, Scott; Nhan, Terence; Page, Donald; Wege, Richard; Hirst, Phillip; Slavich, Peter

    2013-04-01

    Globally, large areas of coastal and estuarine floodplains are underlain by sulfidic sediments and acid sulfate soils (ASS). These soils can be environmentally hazardous due to their high acidity and large pool of potentially mobile metals. The floodplains are characterised by high spatial and temporal heterogeneity. On coastal floodplains, ASS are of moderate to high salinity, with salts derived mainly from either connate marine sources or oxidation of biogenic sulfides and the subsequent increases in soluble ions (e.g. SO42-) and acidity that follow oxidation. Enhanced acidity also increases the mobilisation of pH-sensitive trace metals such as Fe, Al, Mn, Zn and Ni and contributes to increasing apparent salinity. Ground-based geophysics using electromagnetic (EM) induction techniques have been used successfully and extensively to rapidly map soils for salinity management and precision agriculture. EM induction techniques measure apparent soil electrical conductivity (ECa), which is a function of salinity, clay content, water content, soil mineralogy and temperature to determine the spatial distribution of sub-surface conductivity. In this study, we used ECa as a proxy to map the surface and sub-surface spatial distribution of ASS and associated acidic groundwater. Three EM instruments were used, EM38, DUALEM-421 and EM34, which focus on different depth layers, in a survey of a coastal floodplain in eastern Australia. The EM surveys were calibrated with limited soil sampling and analysis (pH, EC, soluble and exchangeable salts and metals, particle size and titratable actual acidity (TAA)). Using fuzzy k-means clustering analysis, the EM38 and elevation data, from a digital elevation model, clearly identified three classes in the near-surface (0-2m) layers: i) levee soils, ii) fluvial sediment capping and iii) ASS (Fig. 4). Increasing the number of classes did not alter the classes identified. Joint inversion of the DUALEM-421 and EM34 data also identified

  6. Selecting Canopy Zones and Thresholding Approaches to Assess Grapevine Water Status by Using Aerial and Ground-Based Thermal Imaging

    Directory of Open Access Journals (Sweden)

    Daniel Sepúlveda-Reyes

    2016-10-01

    Full Text Available Aerial and terrestrial thermography has become a practical tool to determine water stress conditions in vineyards. However, for proper use of this technique it is necessary to consider vine architecture (canopy zone analysis and image thresholding approaches (determination of the upper and lower baseline temperature values. During the 2014–2015 growing season, an experimental study under different water conditions (slight, mild, moderate, and severe water stress was carried out in a commercial vineyard (Vitis vinifera L., cv. Carménè. In this study thermal images were obtained from different canopy zones by using both aerial (>60 m height and ground-based (sunlit, shadow and nadir views thermography. Using customized code that was written specifically for this research, three different thresholding approaches were applied to each image: (i the standard deviation technique (SDT; (ii the energy balance technique (EBT; and (iii the field reference temperature technique (FRT. Results obtained from three different approaches showed that the EBT had the best performance. The EBT was able to discriminate over 95% of the leaf material, while SDT and FRT were able to detect around 70% and 40% of the leaf material, respectively. In the case of canopy zone analysis, ground-based nadir images presented the best correlations with stomatal conductance (gs and stem water potential (Ψstem, reaching determination coefficients (r2 of 0.73 and 0.82, respectively. The best relationships between thermal indices and plant-based variables were registered during the period of maximum atmospheric demand (near veraison with significant correlations for all methods.

  7. Ground-Based Observations of the Aftermath of the 2010-2011 Great Northern Springtime Storm in Saturn (Invited)

    Science.gov (United States)

    Orton, G. S.; Fletcher, L. N.; Fouchet, T.; Fujiyoshi, T.; Greathouse, T. K.; Momary, T.; Yanamandra-Fisher, P. A.

    2013-12-01

    For the first time, a suite of ground-based and spacecraft instruments were available to detect and characterize one of the rare giant convective storms erupting in Saturn's atmosphere. The storm that erupted on 2010 December 5 created an immense thermal and chemical perturbation of the atmosphere. Most of the perturbation of the visible cloud system had abated within a year of the initial eruption, but changes to the atmosphere were evident at thermal infrared wavelengths, and they continue to the present. Here we review the observations from ground-based stations that include NASA's Infrared Telescope Facility (IRTF) and the Subaru Telescope, both at the summit of Mauna Kea, as well as observations from ESO's Very Large Telescope. Evident in the 5-μm spectral window was the clearing of nearly all clouds around and above the 3-bar level of the atmosphere at the latitude of the primary storm. In the intervening two years, imaging in the same window by the IRTF NSFCam2 instrument shows that the cleared region remains prominent and is filling in with a pre-storm cloud cover only very slowly. Most unexpected was the generation of a stratospheric vortex of high temperatures, 'the beacon' (Fletcher et al. 2011 Science 332, 1413). This phenomenon also continues more than two years later and has been tracked using several mid-infrared imaging instruments: VISIR at the VLT, COMICS at Subaru, and MIRSI at the IRTF using moderate-band filters. More precise determination of its vertical distribution was made using the University of Texas Echelon Cross Echelle Spectrograph (TEXES) at the IRTF, targeting specific lines of CH4 and the H2 quadrupole. All of these measurements, taken in concert, show that the heated region of the stratosphere is diminishing in amplitude, expanding in longitude and slowly sinking in altitude.

  8. Review of commonly used remote sensing and ground-based ...

    African Journals Online (AJOL)

    This review provides an overview of the use of remote sensing data, the development of spectral reflectance indices for detecting plant water stress, and the usefulness of field measurements for ground-truthing purposes. Reliable measurements of plant water stress over large areas are often required for management ...

  9. Asteroseismology of solar-type stars with Kepler: III. Ground-based data

    DEFF Research Database (Denmark)

    Karoff, Christoffer; Molenda-Żakowicz , J.

    2010-01-01

    We report on the ground-based follow-up program of spectroscopic and photometric observations of solar-like asteroseismic targets for the Kepler space mission. These stars constitute a large group of more than a thousand objects which are the subject of an intensive study by the Kepler Asteroseis......We report on the ground-based follow-up program of spectroscopic and photometric observations of solar-like asteroseismic targets for the Kepler space mission. These stars constitute a large group of more than a thousand objects which are the subject of an intensive study by the Kepler...

  10. Exoplanets -New Results from Space and Ground-based Surveys

    Science.gov (United States)

    Udry, Stephane

    The exploration of the outer solar system and in particular of the giant planets and their environments is an on-going process with the Cassini spacecraft currently around Saturn, the Juno mission to Jupiter preparing to depart and two large future space missions planned to launch in the 2020-2025 time frame for the Jupiter system and its satellites (Europa and Ganymede) on the one hand, and the Saturnian system and Titan on the other hand [1,2]. Titan, Saturn's largest satellite, is the only other object in our Solar system to possess an extensive nitrogen atmosphere, host to an active organic chemistry, based on the interaction of N2 with methane (CH4). Following the Voyager flyby in 1980, Titan has been intensely studied from the ground-based large telescopes (such as the Keck or the VLT) and by artificial satellites (such as the Infrared Space Observatory and the Hubble Space Telescope) for the past three decades. Prior to Cassini-Huygens, Titan's atmospheric composition was thus known to us from the Voyager missions and also through the explorations by the ISO. Our perception of Titan had thus greatly been enhanced accordingly, but many questions remained as to the nature of the haze surrounding the satellite and the composition of the surface. The recent revelations by the Cassini-Huygens mission have managed to surprise us with many discoveries [3-8] and have yet to reveal more of the interesting aspects of the satellite. The Cassini-Huygens mission to the Saturnian system has been an extraordinary success for the planetary community since the Saturn-Orbit-Insertion (SOI) in July 2004 and again the very successful probe descent and landing of Huygens on January 14, 2005. One of its main targets was Titan. Titan was revealed to be a complex world more like the Earth than any other: it has a dense mostly nitrogen atmosphere and active climate and meteorological cycles where the working fluid, methane, behaves under Titan conditions the way that water does on

  11. Variation in risk and outcomes of Epstein-Barr virus-associated breast cancer by epidemiologic characteristics and virus detection strategies: an exploratory study.

    Science.gov (United States)

    Glaser, Sally L; Canchola, Alison J; Keegan, Theresa H M; Clarke, Christina A; Longacre, Teri A; Gulley, Margaret L

    2017-04-01

    A relationship of Epstein-Barr virus (EBV) and breast cancer etiology and outcome may have clinical utility and potential to enhance understanding of tumor biology. Research to date has yielded variable results, likely reflecting differing virus detection assays and unaddressed epidemiologic heterogeneity across studies. Applying our novel, five-target assay detection strategy in an exploratory study, we examined demographic, clinical, and tumor characteristics, and overall survival, associated with EBV positivity in breast adenocarcinomas from 59 non-Hispanic white and 68 Hispanic women sampled by age (<50, 50+) and stage (localized, regional/remote) and examined associations based on single assay targets. EBV was localized only to lymphocytes. Nevertheless, viral prevalence, although low, varied across patient subgroups. Adjusted odds ratios (OR) for EBV positivity were lower for younger Hispanic than white women (p interaction  = 0.05), and marginally higher for larger [OR (95% confidence intervals) 1.03 (1.00-1.05) per mm increase] and right-sided [2.8 (0.97-7.8)] tumors. In whites, ORs were marginally higher for larger tumors [1.04 (1.00-1.07)] and marginally lower for age 50+ [0.24 (0.06-1.03)]; in Hispanics, ORs were higher for ER negative [5.6 (1.1-30.5)], and marginally higher for right-sided, tumors [5.8 (0.94-36.2)]. Survival was suggestively poorer for EBV-positive than EBV-negative tumors in older women with localized disease. EBV associations differed across single assay targets, indicating variation in prior findings likely due to assay performance. The differing EBV associations by age and race/ethnicity suggest a non-random role of EBV in breast cancer and support further study using multi-target assays, relevant epidemiologic design, and a larger study sample.

  12. Reconciling Ground-Based and Space-Based Estimates of the Frequency of Occurrence and Radiative Effect of Clouds around Darwin, Australia

    Energy Technology Data Exchange (ETDEWEB)

    Protat, Alain; Young, Stuart; McFarlane, Sally A.; L' Ecuyer, Tristan; Mace, Gerald G.; Comstock, Jennifer M.; Long, Charles N.; Berry, Elizabeth; Delanoe, Julien

    2014-02-01

    The objective of this paper is to investigate whether estimates of the cloud frequency of occurrence and associated cloud radiative forcing as derived from ground-based and satellite active remote sensing and radiative transfer calculations can be reconciled over a well instrumented active remote sensing site located in Darwin, Australia, despite the very different viewing geometry and instrument characteristics. It is found that the ground-based radar-lidar combination at Darwin does not detect most of the cirrus clouds above 10 km (due to limited lidar detection capability and signal obscuration by low-level clouds) and that the CloudSat radar - Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) combination underreports the hydrometeor frequency of occurrence below 2 km height, due to instrument limitations at these heights. The radiative impact associated with these differences in cloud frequency of occurrence is large on the surface downwelling shortwave fluxes (ground and satellite) and the top-of atmosphere upwelling shortwave and longwave fluxes (ground). Good agreement is found for other radiative fluxes. Large differences in radiative heating rate as derived from ground and satellite radar-lidar instruments and RT calculations are also found above 10 km (up to 0.35 Kday-1 for the shortwave and 0.8 Kday-1 for the longwave). Given that the ground-based and satellite estimates of cloud frequency of occurrence and radiative impact cannot be fully reconciled over Darwin, caution should be exercised when evaluating the representation of clouds and cloud-radiation interactions in large-scale models and limitations of each set of instrumentation should be considered when interpreting model-observations differences.

  13. Validation of the CrIS fast physical NH3 retrieval with ground-based FTIR

    Directory of Open Access Journals (Sweden)

    E. Dammers

    2017-07-01

    Full Text Available Presented here is the validation of the CrIS (Cross-track Infrared Sounder fast physical NH3 retrieval (CFPR column and profile measurements using ground-based Fourier transform infrared (FTIR observations. We use the total columns and profiles from seven FTIR sites in the Network for the Detection of Atmospheric Composition Change (NDACC to validate the satellite data products. The overall FTIR and CrIS total columns have a positive correlation of r  =  0.77 (N  =  218 with very little bias (a slope of 1.02. Binning the comparisons by total column amounts, for concentrations larger than 1.0  ×  1016 molecules cm−2, i.e. ranging from moderate to polluted conditions, the relative difference is on average ∼ 0–5 % with a standard deviation of 25–50 %, which is comparable to the estimated retrieval uncertainties in both CrIS and the FTIR. For the smallest total column range (< 1.0  × 1016 molecules cm−2 where there are a large number of observations at or near the CrIS noise level (detection limit the absolute differences between CrIS and the FTIR total columns show a slight positive column bias. The CrIS and FTIR profile comparison differences are mostly within the range of the single-level retrieved profile values from estimated retrieval uncertainties, showing average differences in the range of  ∼ 20 to 40 %. The CrIS retrievals typically show good vertical sensitivity down into the boundary layer which typically peaks at  ∼ 850 hPa (∼ 1.5 km. At this level the median absolute difference is 0.87 (std  =  ±0.08 ppb, corresponding to a median relative difference of 39 % (std  =  ±2 %. Most of the absolute and relative profile comparison differences are in the range of the estimated retrieval uncertainties. At the surface, where CrIS typically has lower sensitivity, it tends to overestimate in low-concentration conditions and underestimate

  14. Ground-based and satellite remote sensing of paroxysmal eruptions at Etna volcano, 2011-2012

    Science.gov (United States)

    Bonny, Estelle

    Mt Etna's activity has increased during the last decade with a tendency towards more explosive eruptions that produce paroxysmal lava fountains. From January 2011 to April 2012, 25 lava fountaining episodes took place at Etna's New South-East Crater (NSEC). Improved understanding of the mechanism driving these explosive basaltic eruptions is needed to reduce volcanic hazards. This type of activity produces high sulfur dioxide (SO2) emissions, associated with lava flows and ash fall-out, but to date the SO2 emissions associated with Etna's lava fountains have been poorly constrained. The Ultraviolet (UV) Ozone Monitoring Instrument (OMI) on NASA's Aura satellite and the Atmospheric Infrared Sounder (AIRS) on Aqua were used to measure the SO2 loadings. Ground-based data from the Observatoire de Physique du Globe de Clermont-Ferrand (OPGC) L-band Doppler radar, VOLDORAD 2B, used in collaboration with the Italian National Institute of Geophysics and Volcanology in Catania (INGV-CT), also detected the associated ash plumes, giving precise timing and duration for the lava fountains. This study resulted in the first detailed analysis of the OMI and AIRS SO2 data for Etna's lava fountains during the 2011-2012 eruptive cycle. The HYSPLIT trajectory model is used to constrain the altitude of the observed SO2 clouds, and results show that the SO2 emission usually coincided with the lava fountain peak intensity as detected by VOLDORAD. The UV OMI and IR AIRS SO2 retrievals permit quantification of the SO2 loss rate in the volcanic SO2 clouds, many of which were tracked for several days after emission. A first attempt to quantitatively validate AIRS SO2 retrievals with OMI data revealed a good correlation for high altitude SO2 clouds. Using estimates of the emitted SO2 at the time each paroxysm, we observe a correlation with the inter-paroxysm repose time. We therefore suggest that our data set supports the collapsing foam (CF) model [1] as driving mechanism for the paroxysmal

  15. Chemometrics-assisted high performance liquid chromatography-diode array detection strategy to solve varying interfering patterns from different chromatographic columns and sample matrices for beverage analysis.

    Science.gov (United States)

    Yin, Xiao-Li; Wu, Hai-Long; Gu, Hui-Wen; Hu, Yong; Wang, Li; Xia, Hui; Xiang, Shou-Xia; Yu, Ru-Qin

    2016-02-26

    This work reports a chemometrics-assisted high performance liquid chromatography-diode array detection (HPLC-DAD) strategy to solve varying interfering patterns from different chromatographic columns and sample matrices for the rapid simultaneous determination of six synthetic colorants in five kinds of beverages with little sample pretreatment. The investigation was performed using two types of LC columns under the same elution conditions. Although analytes using different columns have different co-elution patterns that appear more seriously in complex backgrounds, all colorants were properly resolved by alternating trilinear decomposition (ATLD) method and accurate chromatographic elution profiles, spectral profiles as well as relative concentrations were obtained. The results were confirmed by those obtained from traditional HPLC-UV method at a particular wavelength and the results of both methods were consistent with each other. All results demonstrated that the proposed chemometrics-assisted HPLC-DAD method is accurate, economical and universal, and can be promisingly applied to solve varying interfering patterns from different chromatographic columns and sample matrices for the analysis of complex food samples. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Integrated hierarchical geo-environmental survey strategy applied to the detection and investigation of an illegal landfill: A case study in the Campania Region (Southern Italy).

    Science.gov (United States)

    Di Fiore, Vincenzo; Cavuoto, Giuseppe; Punzo, Michele; Tarallo, Daniela; Casazza, Marco; Guarriello, Silvio Marco; Lega, Massimiliano

    2017-10-01

    This paper describes an approach to detect and investigate the main characteristics of a solid waste landfill through the integration of geological, geographical and geophysical methods. In particular, a multi-temporal analysis of the landfill morphological evolution was carried out using aerial and satellite photos, since there were no geological and geophysical data referring to the study area. Subsequently, a surface geophysical prospection was performed through geoelectric and geomagnetic methods. In particular, the combination of electrical resistivity, induced polarization and magnetic measurements removed some of the uncertainties, generally associated with a separate utilization of these techniques. This approach was successfully tested to support the Prosecutor Office of Salerno (S Italy) during a specific investigation about an illegal landfill. All the collected field data supported the reconstruction of the site-specific history, while the real quarry geometry and site geology were defined. Key elements of novelty of this method are the combination and the integration of different methodological approaches, as the parallel and combined use of satellite, aerial and in-situ collected data, that were validated in a real investigation and that revealed the effectiveness of this strategy. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Effective Strategy for Conformer-Selective Detection of Short-Lived Excited State Species: Application to the IR Spectroscopy of the N1H Keto Tautomer of Guanine.

    Science.gov (United States)

    Asami, Hiroya; Tokugawa, Munefumi; Masaki, Yoshiaki; Ishiuchi, Shun-Ichi; Gloaguen, Eric; Seio, Kohji; Saigusa, Hiroyuki; Fujii, Masaaki; Sekine, Mitsuo; Mons, Michel

    2016-04-14

    The ultrafast deactivation processes in the excited state of biomolecules, such as the most stable tautomers of guanine, forbid any state-of-the-art gas phase spectroscopic studies on these species with nanosecond lasers. This drawback can be overcome by grafting a chromophore having a long-lived excited state to the molecule of interest, allowing thus a mass-selective detection by nanosecond R2PI and therefore double resonance IR/UV conformer-selective spectroscopic studies. The principle is presently demonstrated on the keto form of a modified 9-methylguanine, for which the IR/UV double resonance spectrum in the C═O stretch region, reported for the first time, provides evidence for extensive vibrational couplings within the guanine moiety. Such a successful strategy opens up a route to mass-selective IR/UV spectroscopic investigations on molecules exhibiting natural chromophores having ultrashort-lived excited states, such as DNA bases, their complexes as well as peptides containing short-lived aromatic residues.

  18. Retrieval of liquid water cloud properties from ground-based remote sensing observations

    NARCIS (Netherlands)

    Knist, C.L.

    2014-01-01

    Accurate ground-based remotely sensed microphysical and optical properties of liquid water clouds are essential references to validate satellite-observed cloud properties and to improve cloud parameterizations in weather and climate models. This requires the evaluation of algorithms for retrieval of

  19. Coastal wind study based on Sentinel-1 and ground-based scanning lidar

    DEFF Research Database (Denmark)

    Hasager, Charlotte Bay; Badger, Merete; Pena Diaz, Alfredo

    Winds in the coastal zone have importance for near-shore wind farm planning. Recently the Danish Energy Agency gave new options for placing offshore wind farms much closer to the coastlines than previously. The new tender areas are located from 3 to 8 km from the coast. Ground-based scanning lida...... projects and satellite data from Copernicus Sentinel-1....

  20. Ground-based remote sensing scheme for monitoring aerosol-cloud interactions

    NARCIS (Netherlands)

    Sarna, K.; Russchenberg, H.W.J.

    2016-01-01

    A new method for continuous observation of aerosol–cloud interactions with ground-based remote sensing instruments is presented. The main goal of this method is to enable the monitoring of the change of the cloud droplet size due to the change in the aerosol concentration. We use high-resolution

  1. Ground-based remote sensing scheme for monitoring aerosol–cloud interactions (discussion)

    NARCIS (Netherlands)

    Sarna, K.; Russchenberg, H.W.J.

    2015-01-01

    A method for continuous observation of aerosol–cloud interactions with ground-based remote sensing instruments is presented. The main goal of this method is to enable the monitoring of cloud microphysical changes due to the changing aerosol concentration. We use high resolution measurements from

  2. On reconciling ground-based with spaceborne normalized radar cross section measurements

    DEFF Research Database (Denmark)

    Baumgartner, Francois; Munk, Jens; Jezek, K C

    2002-01-01

    This study examines differences in the normalized radar cross section, derived from ground-based versus spaceborne radar data. A simple homogeneous half-space model, indicates that agreement between the two improves as 1) the distance from the scatterer is increased; and/or 2) the extinction...

  3. Ground-based LIDAR: a novel approach to quantify fine-scale fuelbed characteristics

    Science.gov (United States)

    E.L. Loudermilk; J.K. Hiers; J.J. O’Brien; R.J. Mitchell; A. Singhania; J.C. Fernandez; W.P. Cropper; K.C. Slatton

    2009-01-01

    Ground-based LIDAR (also known as laser ranging) is a novel technique that may precisely quantify fuelbed characteristics important in determining fire behavior. We measured fuel properties within a south-eastern US longleaf pine woodland at the individual plant and fuelbed scale. Data were collected using a mobile terrestrial LIDAR unit at sub-cm scale for individual...

  4. Close-up of primary and secondary asteroseismic CoRoT targets and the ground-based follow-up observations

    Energy Technology Data Exchange (ETDEWEB)

    Uytterhoeven, K; Poretti, E; Rainer, M; Mantegazza, L [INAF-Brera Astronomical Observatory, Via E. Bianchi 46, 23807 Merate (Italy); Zima, W; Aerts, C; Morel, T; Lefever, K [Institute of Astronomy, KULeuven, Celestijnenlaan 200D, 3001 Leuven (Belgium); Miglio, A [Institut d' Astrophysique et de Geophysique de l' Universite de Liege, Allee du 6 Aout 17, 4000 Liege (Belgium); Amado, P J; MartIn-Ruiz, S [Instituto de AstrofIsica de AndalucIa (CSIC), Apartado 3004, 18080 Granada (Spain); Mathias, P; Valtier, J C [Observatoire de la Cote d' Azur, GEMINI, CNRS, Universite Nice Sophia-Antipolis, BP 4229, 06304 Nice Cedex 4 (France); Paparo, M; Benkoe, J M [Konkoly Observatory, PO Box 67, 1525 Budapest (Hungary)], E-mail: katrien.uytterhoeven@brera.inaf.it

    2008-10-15

    To optimise the science results of the asteroseismic part of the CoRoT satellite mission a complementary simultaneous ground-based observational campaign is organised for selected CoRoT targets. The observations include both high-resolution spectroscopic and multicolour photometric data. We present the preliminary results of the analysis of the ground-based observations of three targets. A line-profile analysis of 216 high-resolution FEROS spectra of the {delta} Sct star HD 50844 reveals more than ten pulsation frequencies in the frequency range 5-18 d{sup -1}, including possibly one radial fundamental mode (6.92 d{sup -1}). Based on more than 600 multi-colour photometric datapoints of the {beta} Cep star HD 180642, spanning about three years and obtained with different telescopes and different instruments, we confirm the presence of a dominant radial mode {nu}{sub 1} = 5.48695 d{sup -1}, and detect also its first two harmonics. We find evidence for a second mode {nu}{sub 2} = 0.3017 d{sup -1}, possibly a g-mode, and indications for two more frequencies in the 7-8 d{sup -1} domain. From Stromgren photometry we find evidence for the hybrid 5 Sct/{gamma} Dor character of the F0 star HD 44195, as frequencies near 3 d{sup -1} and 21 d{sup -1} are detected simultaneously in the different filters.

  5. Novel Photosensor "ReFerence" for Ground-Based Gamma-Ray Astronomy and Water Cherenkov Neutrino Physics

    Science.gov (United States)

    Ferenc, Daniel; Laille, Alvin; Bratton, Clayton

    2002-04-01

    A novel photosensor concept "ReFerence" was invented in order to provide multiple increase in the detection efficiency of Cherenkov photons in ground-based atmospheric Cherenkov Telescopes (ACT). The particular goal was to lower the gamma-ray detection threshold of the MAGIC telescope down to about 10 GeV. The "ReFerence" photosensor concept is unique in providing: more than twofold increase in quantum efficiency compared to photomultiplier tubes (PMT), excellent single-photon resolution (just as in HPDs), diminished thermionic noise, unprecedented magnetic shielding, negligible dead area, flat angular acceptance with sharp cutoff, hexagonal packing into large-area flat-panel cameras, manifest conceptual and constructional simplicity, extreme robustness and implosion safety, and low price. An extension of the "ReFerence" concept, the so called "TransReFerence", provides two very important additional (even originally unexpected) features - single-photon color sensitivity without destructive filtering, and multiple extension of the spectral sensitivity range. First "ReFerence" photosensor prototype was recently constructed and tested at UC Davis, and the results have verified the "ReFerence" concept. Development of a new fully functional prototype, based on super-sensitive GaAs-type photocathodes, has recently started in collaboration with the ITT Night Vision Industries. In this talk we will summarise the "ReFerence" concept, discuss its benefits for gamma-ray astronomy, and present the latest results of prototype tests.

  6. Remote Sensing of Sonoran Desert Vegetation Structure and Phenology with Ground-Based LiDAR

    Directory of Open Access Journals (Sweden)

    Joel B. Sankey

    2014-12-01

    Full Text Available Long-term vegetation monitoring efforts have become increasingly important for understanding ecosystem response to global change. Many traditional methods for monitoring can be infrequent and limited in scope. Ground-based LiDAR is one remote sensing method that offers a clear advancement to monitor vegetation dynamics at high spatial and temporal resolution. We determined the effectiveness of LiDAR to detect intra-annual variability in vegetation structure at a long-term Sonoran Desert monitoring plot dominated by cacti, deciduous and evergreen shrubs. Monthly repeat LiDAR scans of perennial plant canopies over the course of one year had high precision. LiDAR measurements of canopy height and area were accurate with respect to total station survey measurements of individual plants. We found an increase in the number of LiDAR vegetation returns following the wet North American Monsoon season. This intra-annual variability in vegetation structure detected by LiDAR was attributable to a drought deciduous shrub Ambrosia deltoidea, whereas the evergreen shrub Larrea tridentata and cactus Opuntia engelmannii had low variability. Benefits of using LiDAR over traditional methods to census desert plants are more rapid, consistent, and cost-effective data acquisition in a high-resolution, 3-dimensional context. We conclude that repeat LiDAR measurements can be an effective method for documenting ecosystem response to desert climatology and drought over short time intervals and at detailed-local spatial scale.

  7. How Well the Early 2017 California Atmospheric River Precipitation Events Were Captured by Satellite Products and Ground-based Radars?

    Science.gov (United States)

    Wen, Y. B.; Behrangi, A.; Chen, H.; Lambrigtsen, B.

    2017-12-01

    In January and February of 2017, California experienced multiple heavy storms that caused serious destruction of facilities and economic loss, although it also helped to reduce water storage deficit due to prolonged drought in previous years. These extreme precipitation events were mainly associated with Atmospheric Rivers (ARs) and brought about 174 km3 of water to California according to ground observations. This paper evaluates the performance of six commonly used satellite-based precipitation products (IMERG, 3B42RT, PERSIANN, CCS, CMORPH, and GSMaP), as well as ground-based radar products (Radar-only and Radar-lgc) in capturing the ARs precipitation rate and distribution. It is found that precipitation maps from all products present heavy precipitation in January and February, with more consistent observations over ocean than land. Though large uncertainties exist in quantitative precipitation estimation (QPE) over land, the ensemble mean of different remote sensing precipitation products over California is consistent with gauge measurements. Among the six satellite-based products, IMERG correlates the best with gauge observations both in the detection and quantification of precipitation, but it is not the best product in terms of root mean square error (RMSE) or bias. Compared to satellite products, ground weather radar shows better precipitation detectability and estimation skill. However, neither radar nor satellite QPE products have good performances in quantifying the peak precipitation intensity during the extreme events, suggesting that further advancement in quantification of extremely intense precipitation associated with AR in the Western United States is needed.

  8. Technical Note: New ground-based FTIR measurements at Ile de La Réunion: observations, error analysis, and comparisons with independent data

    Directory of Open Access Journals (Sweden)

    C. Senten

    2008-07-01

    Full Text Available Ground-based high spectral resolution Fourier-transform infrared (FTIR solar absorption spectroscopy is a powerful remote sensing technique to obtain information on the total column abundances and on the vertical distribution of various constituents in the atmosphere. This work presents results from two FTIR measurement campaigns in 2002 and 2004, held at Ile de La Réunion (21° S, 55° E. These campaigns represent the first FTIR observations carried out at a southern (subtropical site. They serve the initiation of regular, long-term FTIR monitoring at this site in the near future. To demonstrate the capabilities of the FTIR measurements at this location for tropospheric and stratospheric monitoring, a detailed report is given on the retrieval strategy, information content and corresponding full error budget evaluation for ozone (O3, methane (CH4, nitrous oxide (N2O, carbon monoxide (CO, ethane (C2H6, hydrogen chloride (HCl, hydrogen fluoride (HF and nitric acid (HNO3 total and partial column retrievals. Moreover, we have made a thorough comparison of the capabilities at sea level altitude (St.-Denis and at 2200 m a.s.l. (Maïdo. It is proved that the performances of the technique are such that the atmospheric variability can be observed, at both locations and in distinct altitude layers. Comparisons with literature and with correlative data from ozone sonde and satellite (i.e., ACE-FTS, HALOE and MOPITT measurements are given to confirm the results. Despite the short time series available at present, we have been able to detect the seasonal variation of CO in the biomass burning season, as well as the impact of particular biomass burning events in Africa and Madagascar on the atmospheric composition above Ile de La Réunion. We also show that differential measurements between St.-Denis and Maïdo provide useful information about the concentrations in the boundary layer.

  9. Magnetoseismology ground-based remote sensing of Earth's magnetosphere

    CERN Document Server

    Menk, Frederick W

    2013-01-01

    Written by a researcher at the forefront of the field, this first comprehensive account of magnetoseismology conveys the physics behind these movements and waves, and explains how to detect and investigate them. Along the way, it describes the principles as applied to remote sensing of near-Earth space and related remote sensing techniques, while also comparing and intercalibrating magnetoseismology with other techniques. The example applications include advanced data analysis techniques that may find wider used in areas ranging from geophysics to medical imaging, and remote sensing using radar systems that are of relevance to defense surveillance systems. As a result, the book not only reviews the status quo, but also anticipates new developments. With many figures and illustrations, some in full color, plus additional computational codes for analysis and evaluation. Aimed at graduate readers, the text assumes knowledge of electromagnetism and physical processes at degree level, but introductory chapters wil...

  10. Multisatellite and ground-based observations of transient ULF waves

    International Nuclear Information System (INIS)

    Potemra, T.A.; Zanetti, L.J.; Takahashi, K.; Erlandson, R.E.; Luehr, H.; Marklund, G.T.; Block, L.P.; Blomberg, L.G.; Lepping, R.P.

    1989-01-01

    A unique alignment of the Active Magnetospheric Particle Tracer Explorers (AMPTE) CCE and Viking satellites with respect to the EISCAT Magnetometer Cross has provided an opportunity to study transient ULF pulsations associated with variations in solar wind plasma density observed by the IMP 8 satellite. These observations were acquired during a relatively quiet period on April 24, 1986, during the Polar Region and Outer Magnetosphere International Study (PROMIS) period. An isolated 4-mHz (4-min period) pulsation was detected on the ground which was associated with transverse magnetic field oscillations observed by Viking at a ∼ 2-R E altitude above the auroral zone and by CCE at ∼ 8-R E in the equatorial plane on nearly the same flux tube. CCE detected a compressional oscillation in the magnetic field with twice the period (∼ 10 min) of the transverse waves, and with a waveform nearly identical to an isolated oscillation in the solar wind plasma density measured by IMP 8. The authors conclude that the isolated 10-min oscillation in solar wind plasma density produced magnetic field compression oscillations inside the magnetosphere at the same frequency which also enhanced resonant oscillations at approximately twice the frequency that were already present. The ground magnetic field variations are due to ionospheric Hall currents driven by the electric field of the standing Alfven waves. The time delay between surface and satellite data acquired at different local times supports the conclusion that the periodic solar wind density variation excites a tailward traveling large-scale magnetosphere wave train which excites local field line resonant oscillations. They conclude that these transient magnetic field variations are not associated with magnetic field reconnection or flux transfer events

  11. An exploration of counterfeit medicine surveillance strategies guided by geospatial analysis: lessons learned from counterfeit Avastin detection in the US drug supply chain.

    Science.gov (United States)

    Cuomo, Raphael E; Mackey, Tim K

    2014-12-02

    To explore healthcare policy and system improvements that would more proactively respond to future penetration of counterfeit cancer medications in the USA drug supply chain using geospatial analysis. A statistical and geospatial analysis of areas that received notices from the Food and Drug Administration (FDA) about the possibility of counterfeit Avastin penetrating the US drug supply chain. Data from FDA warning notices were compared to data from 44 demographic variables available from the US Census Bureau via correlation, means testing and geospatial visualisation. Results were interpreted in light of existing literature in order to recommend improvements to surveillance of counterfeit medicines. This study analysed 791 distinct healthcare provider addresses that received FDA warning notices across 30,431 zip codes in the USA. Statistical outputs were Pearson's correlation coefficients and t values. Geospatial outputs were cartographic visualisations. These data were used to generate the overarching study outcome, which was a recommendation for a strategy for drug safety surveillance congruent with existing literature on counterfeit medication. Zip codes with greater numbers of individuals age 65+ and greater numbers of ethnic white individuals were most correlated with receipt of a counterfeit Avastin notice. Geospatial visualisations designed in conjunction with statistical analysis of demographic variables appeared more capable of suggesting areas and populations that may be at risk for undetected counterfeit Avastin penetration. This study suggests that dual incorporation of statistical and geospatial analysis in surveillance of counterfeit medicine may be helpful in guiding efforts to prevent, detect and visualise counterfeit medicines penetrations in the US drug supply chain and other settings. Importantly, the information generated by these analyses could be utilised to identify at-risk populations associated with demographic characteristics

  12. Potential use of SERS-assisted theranostic strategy based on Fe{sub 3}O{sub 4}/Au cluster/shell nanocomposites for bio-detection, MRI, and magnetic hyperthermia

    Energy Technology Data Exchange (ETDEWEB)

    Han, Yu; Lei, Sheng-lan [Department of Biomaterials, College of Materials, Xiamen University, Xiamen 361005 (China); Lu, Jian-hua [Department of Electronic Science, College of Physical Science and Technology, Fujian Provincial Key Laboratory of Plasma and Magnetic Resonance Research, Xiamen University, Xiamen 361005 (China); He, Yuan [Department of Biomaterials, College of Materials, Xiamen University, Xiamen 361005 (China); Chen, Zhi-wei, E-mail: chenzhiwei@xmu.edu.cn [Department of Electronic Science, College of Physical Science and Technology, Fujian Provincial Key Laboratory of Plasma and Magnetic Resonance Research, Xiamen University, Xiamen 361005 (China); Ren, Lei, E-mail: renlei@xmu.edu.cn [Department of Biomaterials, College of Materials, Xiamen University, Xiamen 361005 (China); State Key Laboratory for Physical Chemistry of Solid Surfaces, Xiamen University, Xiamen 361005 (China); Fujian Collaborative Innovation Center for Exploitation and Utilization of Marine Biological Resources, Xiamen 361005 (China); Zhou, Xi [Department of Biomaterials, College of Materials, Xiamen University, Xiamen 361005 (China); Fujian Provincial Key Laboratory of Fire Retardant Materials, Xiamen University, Xiamen 361005 (China); Fujian Collaborative Innovation Center for Exploitation and Utilization of Marine Biological Resources, Xiamen 361005 (China)

    2016-07-01

    A surface-enhanced Raman scattering (SERS)-assisted theranostic strategy was designed based on a synthesized multifunctional Fe{sub 3}O{sub 4}/Au cluster/shell nanocomposite. This theranostic strategy was used for free prostate specific antigen (free-PSA) detection, magnetic resonance imaging (MRI), and magnetic hyperthermia. The lowest protein concentration detected was 1 ng mL{sup −1}, and the limit of detection (LOD) of the calculated PSA was 0.75 ng mL{sup −1}. Then, MRI was carried out to visualize the tumor cell. Lastly, magnetic hyperthermia was employed and revealed a favorable killing effect for the tumor cells. Thus, this SERS-assisted strategy based on a Fe{sub 3}O{sub 4}/Au cluster/shell nanocomposite showed great advantages in theranostic treatment. - Graphical abstract: Fe{sub 3}O{sub 4}/Au cluster/shell composite can be used for specific protein detection, magnetic resonance imaging and magnetic hyperthermia therapy. - Highlights: • We designed a SERS-assisted theranostic strategy based on the mutifunctional nanocomposites using gold shelled Fe{sub 3}O{sub 4} clusters. • Fe{sub 3}O{sub 4}/Au nanoparticles with theranostics and SERS for early diagnosis of PSA were reported for the first time. • The LOD of detection for PSA was lowed as 0.75 ng mL{sup −1}, and the total detection time was shorten to less than 1 h. • Fe{sub 3}O{sub 4} clusters had spin-spin (T{sub 2}) contrast enhancement and increased magnetic response. • Gold nanoshells supplied excellent chemical stability, biocompatibility, better heating property for magnetic hyperthermia.

  13. Ground-Based VIS/NIR Reflectance Spectra of 25143 Itokawa: What Hayabusa will See and How Ground-Based Data can Augment Analyses

    Science.gov (United States)

    Vilas, Faith; Abell, P. A.; Jarvis, K. S.

    2004-01-01

    Planning for the arrival of the Hayabusa spacecraft at asteroid 25143 Itokawa includes consideration of the expected spectral information to be obtained using the AMICA and NIRS instruments. The rotationally-resolved spatial coverage the asteroid we have obtained with ground-based telescopic spectrophotometry in the visible and near-infrared can be utilized here to address expected spacecraft data. We use spectrophotometry to simulate the types of data that Hayabusa will receive with the NIRS and AMICA instruments, and will demonstrate them here. The NIRS will cover a wavelength range from 0.85 m, and have a dispersion per element of 250 Angstroms. Thus, we are limited in coverage of the 1.0 micrometer and 2.0 micrometer mafic silicate absorption features. The ground-based reflectance spectra of Itokawa show a large component of olivine in its surface material, and the 2.0 micrometer feature is shallow. Determining the olivine to pyroxene abundance ratio is critically dependent on the attributes of the 1.0- and 2.0 micrometer features. With a cut-off near 2,1 micrometer the longer edge of the 2.0- feature will not be obtained by NIRS. Reflectance spectra obtained using ground-based telescopes can be used to determine the regional composition around space-based spectral observations, and possibly augment the longer wavelength spectral attributes. Similarly, the shorter wavelength end of the 1.0 micrometer absorption feature will be partially lost to the NIRS. The AMICA filters mimic the ECAS filters, and have wavelength coverage overlapping with the NIRS spectral range. We demonstrate how merging photometry from AMICA will extend the spectral coverage of the NIRS. Lessons learned from earlier spacecraft to asteroids should be considered.

  14. Historical Trends in Ground-Based Optical Space Surveillance System Design

    Science.gov (United States)

    Shoemaker, M.; Shroyer, L.

    In the spirit of the 50th anniversary of the launch of the first man-made satellite, an historical overview of ground-based optical space surveillance systems is provided. Specific emphasis is given on gathering metrics to analyze design trends. The subject of space surveillance spans the history of spaceflight: from the early tracking cameras at missile ranges, the first observations of Sputnik, to the evolution towards highly capable commercial off-the-shelf (COTS) systems, and much in between. Whereas previous reviews in the literature have been limited in scope to specific time periods, operational programs, countries, etc., a broad overview of a wide range of sources is presented. This review is focused on systems whose primary design purpose can be classified as Space Object Identification (SOI) or Orbit Determination (OD). SOI systems are those that capture images or data to determine information about the satellite itself, such as attitude, features, and material composition. OD systems are those that produce estimates of the satellite position, usually in the form of orbital elements or a time history of tracking angles. Systems are also categorized based on the orbital regime in which their targets reside, which has been simplified in this study to either Low Earth Orbit (LEO) or Geosynchronous Earth Orbit (GEO). The systems are further classified depending on the industry segment (government/commercial or academic), and whether the program is foreign or domestic. In addition to gathering metrics on systems designed solely for man-made satellite observations, it is interesting to find examples of other systems being similarly used. Examples include large astronomical telescopes being used for GEO debris surveys and anomaly resolution for deep-space probes. Another interesting development is the increase in number and capability of COTS systems, some of which are specifically marketed to consumers as satellite trackers. After describing the results of the

  15. Evaluation of Six High-Resolution Satellite and Ground-Based Precipitation Products over Malaysia

    Directory of Open Access Journals (Sweden)

    Mou Leong Tan

    2015-01-01

    Full Text Available Satellite precipitation products (SPPs potentially constitute an alternative to sparse rain gauge networks for assessing the spatial distribution of precipitation. However, applications of these products are still limited due to the lack of robust quality assessment. This study compares daily, monthly, seasonal, and annual rainfall amount at 342 rain gauges over Malaysia to estimations using five SPPs (3B42RT, 3B42V7, GPCP-1DD, PERSIANN-CDR, and CMORPH and a ground-based precipitation product (APHRODITE. The performance of the precipitation products was evaluated from 2003 to 2007 using continuous (RMSE, R2, ME, MAE, and RB and categorical (ACC, POD, FAR, CSI, and HSS statistical approaches. Overall, 3B42V7 and APHRODITE performed the best, while the worst performance was shown by GPCP-1DD. 3B42RT, 3B42V7, and PERSIANN-CDR slightly overestimated observed precipitation by 2%, 4.7%, and 2.1%, respectively. By contrast, APHRODITE and CMORPH significantly underestimated precipitations by 19.7% and 13.2%, respectively, whereas GPCP-1DD only slightly underestimated by 2.8%. All six precipitation products performed better in the northeast monsoon than in the southwest monsoon. The better performances occurred in eastern and southern Peninsular Malaysia and in the north of East Malaysia, which receives higher rainfall during the northeast monsoon, whereas poor performances occurred in the western and dryer Peninsular Malaysia. All precipitation products underestimated the no/tiny (<1 mm/day and extreme (≥20 mm/day rainfall events, while they overestimated low (1–20 mm/day rainfall events. 3B42RT and 3B42V7 showed the best ability to detect precipitation amounts with the highest HSS value (0.36. Precipitations during flood events such as those which occurred in late 2006 and early 2007 were estimated the best by 3B42RT and 3B42V7, as shown by an R2 value ranging from 0.49 to 0.88 and 0.52 to 0.86, respectively. These results on SPPs’ uncertainties

  16. Study of Solar-Terrestrial Connections in the Highlight of Simultaneous Observations with STEREO and UTR-2, URAN, NDA Ground-Based Radio Telescopes

    Science.gov (United States)

    Melnik, V. N.; Rucker, H. O.; Konovalenko, A. A.; Lecacheux, A.; Falkovich, I. S.

    In the present paper new opportunities, which will be appeared at simultaneous observations by STEREO and ground-based radio telescopes (UTR-2, URAN, NDA), in study of solar sporadic phenomena, having essential effects on the Earth, are discussed. CMEs, which manifest themselves in radio emission as Type II and Type IY bursts, are the most important of them. Studying of these bursts during simultaneous observations with the help of STEREO and ground-based radio telescopes will allow to find the direction of CME movement, 3D images of CME, its beaming pattern, bulk energy of both CME and shock before it, particle acceleration sites and directions of propagation of accelerated particles. Analyses of radio observations of active and quiet Sun will allow to understand pre-CME conditions in the solar corona and will give an opportunity to forecast CME appearance. Observations of different types of sporadic radio emissions (Type III bursts, drift pairs, s-bursts, bursts in absorption etc.) with high sensitivity, high frequency and time resolutions in decameter range by ground-based radio telescopes and detection of regions, where this radio emission goes out from (using STEREO results), will allow to diagnose the coronal plasmas (to define their density, magnetic fields, parameters of inhomogenieties) at altitudes 0.5-2Rs and to build adequate model of CME formation and its evolution. Using of interplanetary scintillation methods tested on UTR-2 and URAN radio telescope as well as in situ measurements on STEREO will give the information about both CME structure and shock associated with it, about spectra of density fluctuations and turbulences connected with CME at distances about 1a.u. from the Sun.

  17. A new signal-on method for the detection of protein based on binding-induced strategy and photoinduced electron transfer between Ag nanoclusters and split G-quadruplex-hemin complexes

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Kai, E-mail: zhangkai@jsinm.org; Wang, Ke; Zhu, Xue; Xie, Minhao

    2015-08-05

    Proteins play important roles in biological and cellular processes. The levels of proteins can be useful biomarkers for cellular events or disease diagnosis, thus the method for sensitive and selective detection of proteins is imperative to proteins express, study, and clinical diagnosis. Herein, we report a “signal-on” platform for the assay of protein based on binding-induced strategy and photoinduced electron transfer between Ag nanoclusters and split G-quadruplex-hemin complexes. By using biotin as the affinity ligand, this simple protocol could sensitively detect streptavidin with a detection limit down to 10 pM. With the use of an antibody as the affinity ligand, a method for homogeneous fluorescence detection of Prostate Specific Antigen (PSA) was also proposed with a detection limit of 10 pM. The one-step and wash-free assay showed good selectivity. Its high sensitivity, acceptable accuracy, and satisfactory versatility of analytes led to various applications in bioanalysis. - Highlights: • AgNCs have great potential for application in biomedicine. • Binding of two affinity ligands can result in binding-induced DNA assemblies. • PET can be happened between DNA/AgNCs and G-quadruplex/hemin complexes. • A platform for the detection of proteins was proposed by using PET and binding-induced strategy.

  18. First retrievals of methane isotopologues from FTIR ground-based observations

    Science.gov (United States)

    Bader, Whitney; Strong, Kimberly; Walker, Kaley; Buzan, Eric

    2017-04-01

    Atmospheric methane concentrations have reached a new high at 1845 ± 2 ppb, accounting for an increase of 256 % since pre-industrial times (WMO, 2016). In the last ten years, methane has been on the rise again at rates of ˜0.3%/year (e.g., Bader et al., 2016), after a period of stabilization of about 5 years. This recent increase is not fully understood due to remaining uncertainties in the methane budget, influenced by numerous anthropogenic and natural emission sources. In order to examine the cause(s) of this increase, we focus on the two main methane isotopologues, i.e. CH3D and 13CH4. Both CH3D and 13CH4 are emitted in the atmosphere with different ratio depending on the emission processes involved. As heavier isotopologues will react more slowly than 12CH4, each isotopologue will be depleted from the atmosphere at a specific rate depending on the removal process. Methane isotopologues are therefore good tracers of the methane budget. In this contribution, the first development and optimization of the retrieval strategy of CH3D as well as the preliminary tests for 13CH4 will be presented and discussed , using FTIR (Fourier Transform infrared) solar spectra collected at the Eureka (80.05 ˚ N, -86.42 ˚ E, 610 m a.s.l.) and Toronto (43.66˚ N, -79.4˚ E, 174 m a.s.l.) ground-based sites. Mixing ratio vertical profiles from a Whole Atmosphere Community Climate Model (WACCM v.4, Marsh et al., 2013) simulation developed by Buzan et al. (2016) are used as a priori inputs. A discussion on the type of regularization constraints used for the retrievals will be presented as well as an evaluation of available spectroscopy (primarily the different editions of the HITRAN database, see Rothman et al., 2013 and references therein). The uncertainties affecting the retrieved columns as well as information content evaluation will be discussed in order to assess the best strategy to be employed based on its altitude sensitivity range and complete error budget. Acknowledgments

  19. A Manual Transportable Instrument Platform for Ground-Based Spectro-Directional Observations (ManTIS) and the Resultant Hyperspectral Field Goniometer System

    Science.gov (United States)

    Buchhorn, Marcel; Petereit, Reinhold; Heim, Birgit

    2013-01-01

    This article presents and technically describes a new field spectro-goniometer system for the ground-based characterization of the surface reflectance anisotropy under natural illumination conditions developed at the Alfred Wegener Institute (AWI). The spectro-goniometer consists of a Manual Transportable Instrument platform for ground-based Spectro-directional observations (ManTIS), and a hyperspectral sensor system. The presented measurement strategy shows that the AWI ManTIS field spectro-goniometer can deliver high quality hemispherical conical reflectance factor (HCRF) measurements with a pointing accuracy of ±6 cm within the constant observation center. The sampling of a ManTIS hemisphere (up to 30° viewing zenith, 360° viewing azimuth) needs approx. 18 min. The developed data processing chain in combination with the software used for the semi-automatic control provides a reliable method to reduce temporal effects during the measurements. The presented visualization and analysis approaches of the HCRF data of an Arctic low growing vegetation showcase prove the high quality of spectro-goniometer measurements. The patented low-cost and lightweight ManTIS instrument platform can be customized for various research needs and is available for purchase.

  20. Stratospheric OClO and NO2 measured by groundbased UV/Vis-spectroscopy in Greenland in January and February 1990 and 1991

    Science.gov (United States)

    Roth, A.; Perner, D.

    1994-01-01

    Groundbased UV/Vis-spectroscopy of zenith scattered sunlight was performed at Sondre Stromfjord (Greenland) during Jan/Feb 1990 and Jan/Feb 1991. Considerable amounts of OClO were observed during both campaigns. Maximum OClO vertical column densities at 92 deg solar zenith angle (SZA) were 7.4 x 10(exp 13) molec/sq cm in 1990 and 5.7 x 10(exp 13) molec/sq cm in 1991 (chemical enhancement is included in the calculation of the air mass factor (AMF)). A threshold seems to exist for OClO detection: OClO was detected on every day when the potential vorticity at the 475 K level of potential temperature was higher than 35 x 10(exp -6)Km(exp 2)kg(exp -1)s(exp -1). NO2 vertical columns lower than 1 x 10(exp 15) molec/sq cm were frequently observed in both winters.

  1. Big data managing in a landslide early warning system: experience from a ground-based interferometric radar application

    Science.gov (United States)

    Intrieri, Emanuele; Bardi, Federica; Fanti, Riccardo; Gigli, Giovanni; Fidolini, Francesco; Casagli, Nicola; Costanzo, Sandra; Raffo, Antonio; Di Massa, Giuseppe; Capparelli, Giovanna; Versace, Pasquale

    2017-10-01

    A big challenge in terms or landslide risk mitigation is represented by increasing the resiliency of society exposed to the risk. Among the possible strategies with which to reach this goal, there is the implementation of early warning systems. This paper describes a procedure to improve early warning activities in areas affected by high landslide risk, such as those classified as critical infrastructures for their central role in society. This research is part of the project LEWIS (Landslides Early Warning Integrated System): An Integrated System for Landslide Monitoring, Early Warning and Risk Mitigation along Lifelines. LEWIS is composed of a susceptibility assessment methodology providing information for single points and areal monitoring systems, a data transmission network and a data collecting and processing center (DCPC), where readings from all monitoring systems and mathematical models converge and which sets the basis for warning and intervention activities. The aim of this paper is to show how logistic issues linked to advanced monitoring techniques, such as big data transfer and storing, can be dealt with compatibly with an early warning system. Therefore, we focus on the interaction between an areal monitoring tool (a ground-based interferometric radar) and the DCPC. By converting complex data into ASCII strings and through appropriate data cropping and average, and by implementing an algorithm for line-of-sight correction, we managed to reduce the data daily output without compromising the capability for performing.

  2. Alfven Waves Underlying Ionospheric Destabilization: Ground-Based Observations

    Science.gov (United States)

    Hirsch, Michael

    During geomagnetic storms, terawatts of power in the million mile-per-hour solar wind pierce the Earth's magnetosphere. Geomagnetic storms and substorms create transverse magnetic waves known as Alfven waves. In the auroral acceleration region, Alfven waves accelerate electrons up to one-tenth the speed of light via wave-particle interactions. These inertial Alfven wave (IAW) accelerated electrons are imbued with sub-100 meter structure perpendicular to geomagnetic field B. The IAW electric field parallel to B accelerates electrons up to about 10 keV along B. The IAW dispersion relation quantifies the precipitating electron striation observed with high-speed cameras as spatiotemporally dynamic fine structured aurora. A network of tightly synchronized tomographic auroral observatories using model based iterative reconstruction (MBIR) techniques were developed in this dissertation. The TRANSCAR electron penetration model creates a basis set of monoenergetic electron beam eigenprofiles of auroral volume emission rate for the given location and ionospheric conditions. Each eigenprofile consists of nearly 200 broadband line spectra modulated by atmospheric attenuation, bandstop filter and imager quantum efficiency. The L-BFGS-B minimization routine combined with sub-pixel registered electron multiplying CCD video stream at order 10 ms cadence yields estimates of electron differential number flux at the top of the ionosphere. Our automatic data curation algorithm reduces one terabyte/camera/day into accurate MBIR-processed estimates of IAW-driven electron precipitation microstructure. This computer vision structured auroral discrimination algorithm was developed using a multiscale dual-camera system observing a 175 km and 14 km swath of sky simultaneously. This collective behavior algorithm exploits the "swarm" behavior of aurora, detectable even as video SNR approaches zero. A modified version of the algorithm is applied to topside ionospheric radar at Mars and

  3. The bistatic radar capabilities of the Medicina radiotelescopes in space debris detection and tracking

    Science.gov (United States)

    Montebugnoli, S.; Pupillo, G.; Salerno, E.; Pluchino, S.; di Martino, M.

    2010-03-01

    An accurate measurement of the position and trajectory of the space debris fragments is of primary importance for the characterization of the orbital debris environment. The Medicina Radioastronomical Station is a radio observation facility that is here proposed as receiving part of a ground-based space surveillance system for detecting and tracking space debris at different orbital regions (from Low Earth Orbits up to Geostationary Earth Orbits). The proposed system consists of two bistatic radars formed by the existing Medicina receiving antennas coupled with appropriate transmitters. This paper focuses on the current features and future technical development of the receiving part of the observational setup. Outlines of possible transmitting systems will also be given together with the evaluation of the observation strategies achievable with the proposed facilities.

  4. [Development of a ground-based experimental facility for space waste material processing with microorganism].

    Science.gov (United States)

    Ai, Wei-dang; Guo, Shuang-sheng; Wang, Xiao-xia; Fu, Lan

    2004-06-01

    To develop a ground-based experimental facility for microorganism waste processing, which will be used to recover nutrient from plant inedible biomass essential for growth and development of plants. After technical parameters and performance requirements were defined, planning demonstration, drawing design, fabrication, debug and plant inedible residue-biodegradation tests by microorganisms were conducted. The facility worked well, and the parameters, such as energy consumption, volume and weight, met the design requirement. The water-treated quality and the ability of treating plant residual by microorganism were better than the demands. The ground-based results demonstrated that total organic carbon (TOC) degradation above 92.1%, and chemical oxygen demand (COD) reduction over 95.5% could be maintained. The facility has reasonable technical indexes, and smooth and reliable performances. Its major working principle is suitable for the demand of space conditions. It is capable of being utilized for biodegradation of plant inedible biomass in space.

  5. Monitoring of rainfall by ground-based passive microwave systems: models, measurements and applications

    Directory of Open Access Journals (Sweden)

    F. S. Marzano

    2005-01-01

    Full Text Available A large set of ground-based multi-frequency microwave radiometric simulations and measurements during different precipitation regimes are analysed. Simulations are performed for a set of frequencies from 22 to 60 GHz, representing the channels currently available on an operational ground-based radiometric system. Results are illustrated in terms of comparisons between measurements and model data in order to show that the observed radiometric signatures can be attributed to rainfall scattering and absorption. An inversion algorithm has been developed, basing on the simulated data, to retrieve rain rate from passive radiometric observations. As a validation of the approach, we have analyzed radiometric measurements during rain events occurred in Boulder, Colorado, and at the Atmospheric Radiation Measurement (ARM Program's Southern Great Plains (SGP site in Lamont, Oklahoma, USA, comparing rain rate estimates with available simultaneous rain gauge data.

  6. A strategy to improve the detection of drug-induced hepatotoxicity Una estrategia para mejorar la detección de hepatotoxicidad por medicamentos

    Directory of Open Access Journals (Sweden)

    A. Ruiz Montero

    2005-03-01

    Full Text Available Aims: to report a new strategy for the detection of hepatotoxic adverse drug reactions (ADRs in hospitalized patients improving the results obtained with other methods. Design: the model is based on the identification of a single alert signal in various target clinical departments over a 12-month period. Each patient was later interviewed following a set protocol. The main results analyzed were the drugs suspected of ADR; causal relationship between suspected drugs and ADRs; ADR severity, and incidence of hepatotoxic ADR/100,000 inhabitants. Subjects: population served by a university-affiliated urban teaching hospital (519,381 inhabitants. Results: The overall ratio of confirmed/suspected ADRs was high (35/80. The most commonly reported drug was amoxicillin-clavulanic acid (4 cases. With regard to causality, 2 suspected cases were classified as definite and 14 as probable. The distribution according to the severity of hepatotoxicity was 6 severe and 29 mild cases. The incidence of hepatotoxic ADRs/100,000 inhabitants as revealed by our method was much higher versus voluntary report (6.74 and 1.79, respectively. Conclusions: our method has proven effective for improving the detection of hepatotoxic ADRs, and may be extended to other types of adverse reactions.Objetivos: comunicar una nueva estrategia para la detección de reacciones hepatotóxicas por medicamentos que mejora los resultados obtenidos con otros métodos utilizados. Diseño: el modelo se basa en la identificación de una señal de alerta simple en los pacientes de varios servicios diana, durante 12 meses. Cada paciente fue posteriormente entrevistado siguiendo un protocolo específico. Se analizaron: los fármacos sospechosos de producir hepatotoxicidad, la relación de causalidad entre el fármaco sospechoso y la hepatotoxicidad, la gravedad y la incidencia de hepatotoxicidad medicamentosa/100.000 habitantes. Pacientes: la población del área de influencia de nuestro hospital

  7. Depolarization ratio of polar stratospheric clouds in coastal Antarctica: comparison analysis between ground-based Micro Pulse Lidar and space-borne CALIOP observations

    Directory of Open Access Journals (Sweden)

    C. Córdoba-Jabonero

    2013-03-01

    Full Text Available Polar stratospheric clouds (PSCs play an important role in polar ozone depletion, since they are involved in diverse ozone destruction processes (chlorine activation, denitrification. The degree of that ozone reduction is depending on the type of PSCs, and hence on their occurrence. Therefore PSC characterization, mainly focused on PSC-type discrimination, is widely demanded. The backscattering (R and volume linear depolarization (δV ratios are the parameters usually used in lidar measurements for PSC detection and identification. In this work, an improved version of the standard NASA/Micro Pulse Lidar (MPL-4, which includes a built-in depolarization detection module, has been used for PSC observations above the coastal Antarctic Belgrano II station (Argentina, 77.9° S 34.6° W, 256 m a.s.l. since 2009. Examination of the MPL-4 δV feature as a suitable index for PSC-type discrimination is based on the analysis of the two-channel data, i.e., the parallel (p- and perpendicular (s- polarized MPL signals. This study focuses on the comparison of coincident δV-profiles as obtained from ground-based MPL-4 measurements during three Antarctic winters with those reported from the space-borne lidar CALIOP (Cloud-Aerosol Lidar with Orthogonal Polarization aboard the CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation satellite in the same period (83 simultaneous cases are analysed for 2009–2011 austral winter times. Three different approaches are considered for the comparison analysis between both lidar profile data sets in order to test the degree of agreement: the correlation coefficient (CC, as a measure of the relationship between both PSC vertical structures; the mean differences together with their root mean square (RMS values found between data sets; and the percentage differences (BIAS, parameter also used in profiling comparisons between CALIOP and other ground-based lidar systems. All of them are examined as a function

  8. Biosignature Preservation and Detection in Mars Analog Environments.

    Science.gov (United States)

    Hays, Lindsay E; Graham, Heather V; Des Marais, David J; Hausrath, Elisabeth M; Horgan, Briony; McCollom, Thomas M; Parenteau, M Niki; Potter-McIntyre, Sally L; Williams, Amy J; Lynch, Kennda L

    2017-04-01

    This review of material relevant to the Conference on Biosignature Preservation and Detection in Mars Analog Environments summarizes the meeting materials and discussions and is further expanded upon by detailed references to the published literature. From this diverse source material, there is a detailed discussion on the habitability and biosignature preservation potential of five primary analog environments: hydrothermal spring systems, subaqueous environments, subaerial environments, subsurface environments, and iron-rich systems. Within the context of exploring past habitable environments on Mars, challenges common to all of these key environments are laid out, followed by a focused discussion for each environment regarding challenges to orbital and ground-based observations and sample selection. This leads into a short section on how these challenges could influence our strategies and priorities for the astrobiological exploration of Mars. Finally, a listing of urgent needs and future research highlights key elements such as development of instrumentation as well as continued exploration into how Mars may have evolved differently from Earth and what that might mean for biosignature preservation and detection. Key Words: Biosignature preservation-Biosignature detection-Mars analog environments-Conference report-Astrobiological exploration. Astrobiology 17, 363-400.

  9. Ground-Based Meteorological Data (daily, 24 hour files) from Co-Located Ground-Based Global Navigation Satellite System GLONASS (GLObal NAvigation Satellite System) Receivers from NASA CDDIS

    Data.gov (United States)

    National Aeronautics and Space Administration — This dataset consists of ground-based Meteorological Data (daily, 24 hour files) from instruments co-located with Global Navigation Satellite System (GNSS) GLONASS...

  10. Ground-based follow-up of the Gaia-RVS radial velocity standards

    Science.gov (United States)

    Soubiran, C.; Jasniewicz, G.; Zurbach, C.; Crifo, F.; Sartoretti, P.; Katz, D.; Marchal, O.; Panuzzo, P.; Udry, S.

    2016-12-01

    The RVS spectrograph on board of Gaia having no calibration device, radial velocity standards are needed to calibrate the zero-point of the instrument. We have prepared a list of 2798 such stars, well distributed over the sky, and compiled ˜25 000 individual RV measurements from ground-based velocimeters. For a fraction of these stars, their stability at the 300 ms level during the Gaia mission has still to be assessed. The catalogue and follow-up programme are presented.

  11. Testing a ground-based canopy model using the wind river canopy crane

    Science.gov (United States)

    Robert Van Pelt; Malcolm P. North

    1999-01-01

    A ground-based canopy model that estimates the volume of occupied space in forest canopies was tested using the Wind River Canopy Crane. A total of 126 trees in a 0.25 ha area were measured from the ground and directly from a gondola suspended from the crane. The trees were located in a low elevation, old-growth forest in the southern Washington Cascades. The ground-...

  12. NASA Requirements for Ground-Based Pressure Vessels and Pressurized Systems (PVS). Revision C

    Science.gov (United States)

    Greulich, Owen Rudolf

    2017-01-01

    The purpose of this document is to ensure the structural integrity of PVS through implementation of a minimum set of requirements for ground-based PVS in accordance with this document, NASA Policy Directive (NPD) 8710.5, NASA Safety Policy for Pressure Vessels and Pressurized Systems, NASA Procedural Requirements (NPR) 8715.3, NASA General Safety Program Requirements, applicable Federal Regulations, and national consensus codes and standards (NCS).

  13. Study of the unknown hemisphere of mercury by ground-based astronomical facilities

    Science.gov (United States)

    Ksanfomality, L. V.

    2011-08-01

    The short exposure method proved to be very productive in ground-based observations of Mercury. Telescopic observations with short exposures, together with computer codes for the processing of data arrays of many thousands of original electronic photos, make it possible to improve the resolution of images from ground-based instruments to almost the diffraction limit. The resulting composite images are comparable with images from spacecrafts approaching from a distance of about 1 million km. This paper presents images of the hemisphere of Mercury in longitude sectors 90°-180°W, 215°-350°W, and 50°-90°W, including, among others, areas not covered by spacecraft cameras. For the first time a giant S basin was discovered in the sector of longitudes 250°-290°W, which is the largest formation of this type on terrestrial planets. Mercury has a strong phase effects. As a result, the view of the surface changes completely with the change in the planetary phase. But the choice of the phase in the study using spacecrafts is limited by orbital characteristics of the mission. Thus, ground-based observations of the planet provide a valuable support.

  14. Gravitational-Wave Tests of General Relativity with Ground-Based Detectors and Pulsar-Timing Arrays.

    Science.gov (United States)

    Yunes, Nicolás; Siemens, Xavier

    2013-01-01

    This review is focused on tests of Einstein's theory of general relativity with gravitational waves that are detectable by ground-based interferometers and pulsar-timing experiments. Einstein's theory has been greatly constrained in the quasi-linear, quasi-stationary regime, where gravity is weak and velocities are small. Gravitational waves will allow us to probe a complimentary, yet previously unexplored regime: the non-linear and dynamical strong-field regime . Such a regime is, for example, applicable to compact binaries coalescing, where characteristic velocities can reach fifty percent the speed of light and gravitational fields are large and dynamical. This review begins with the theoretical basis and the predicted gravitational-wave observables of modified gravity theories. The review continues with a brief description of the detectors, including both gravitational-wave interferometers and pulsar-timing arrays, leading to a discussion of the data analysis formalism that is applicable for such tests. The review ends with a discussion of gravitational-wave tests for compact binary systems.

  15. Gravitational-Wave Tests of General Relativity with Ground-Based Detectors and Pulsar-Timing Arrays

    Directory of Open Access Journals (Sweden)

    Nicolás Yunes

    2013-11-01

    Full Text Available This review is focused on tests of Einstein's theory of general relativity with gravitational waves that are detectable by ground-based interferometers and pulsar-timing experiments. Einstein’s theory has been greatly constrained in the quasi-linear, quasi-stationary regime, where gravity is weak and velocities are small. Gravitational waves will allow us to probe a complimentary, yet previously unexplored regime: the non-linear and dynamical strong-field regime. Such a regime is, for example, applicable to compact binaries coalescing, where characteristic velocities can reach fifty percent the speed of light and gravitational fields are large and dynamical. This review begins with the theoretical basis and the predicted gravitational-wave observables of modified gravity theories. The review continues with a brief description of the detectors, including both gravitational-wave interferometers and pulsar-timing arrays, leading to a discussion of the data analysis formalism that is applicable for such tests. The review ends with a discussion of gravitational-wave tests for compact binary systems.

  16. Analysis by NASA's VESGEN Software of Vascular Branching in the Human Retina with a Ground-Based Microgravity Analog

    Science.gov (United States)

    Parsons-Wingerter, Patricia; Vyas, Ruchi J.; Raghunandan, Sneha; Vu, Amanda C.; Zanello, Susana B.; Ploutz-Snyder, Robert; Taibbi, Giovanni; Vizzeri, Gianmarco

    2016-01-01

    Significant risks for visual impairment were discovered recently in astronauts following spaceflight, especially after long-duration missions.1 We hypothesize that microgravity-induced fluid shifts result in pathological changes within the retinal vasculature that precede visual and other ocular impairments. We therefore are analyzing retinal vessels in healthy subjects with NASA's VESsel GENeration Analysis (VESGEN) software2 before and after head-down tilt (HDT), a ground-based microgravity analog For our preliminary study of masked images, two groups of venous trees with and without small veins (G=7) were clearly identified by VESGEN analysis. Upon completing all images and unmasking the subject status of pre- and post- HDT, we will determine whether differences in the presence or absence of small veins are important correlates, and perhaps reliable predictors, of other ocular and physiological adaptations to prolonged HDT and microgravity. Greater peripapillary retinal thickening was measured following 70-day HDT bed rest than 14-day HDT bed rest, suggesting that time of HDT may increase the amount of optic disc swelling.3 Spectralis OCT detected retinal nerve fiber layer thickening post HDT, without clinical signs of optic disc edema. Such changes may have resulted from HDT-induced cephalad fluid shifts. Clinical methods for examining adaptive microvascular remodeling in the retina to microgravity space flight are currently not established.

  17. A Semiautomated Multilayer Picking Algorithm for Ice-sheet Radar Echograms Applied to Ground-Based Near-Surface Data

    Science.gov (United States)

    Onana, Vincent De Paul; Koenig, Lora Suzanne; Ruth, Julia; Studinger, Michael; Harbeck, Jeremy P.

    2014-01-01

    Snow accumulation over an ice sheet is the sole mass input, making it a primary measurement for understanding the past, present, and future mass balance. Near-surface frequency-modulated continuous-wave (FMCW) radars image isochronous firn layers recording accumulation histories. The Semiautomated Multilayer Picking Algorithm (SAMPA) was designed and developed to trace annual accumulation layers in polar firn from both airborne and ground-based radars. The SAMPA algorithm is based on the Radon transform (RT) computed by blocks and angular orientations over a radar echogram. For each echogram's block, the RT maps firn segmented-layer features into peaks, which are picked using amplitude and width threshold parameters of peaks. A backward RT is then computed for each corresponding block, mapping the peaks back into picked segmented-layers. The segmented layers are then connected and smoothed to achieve a final layer pick across the echogram. Once input parameters are trained, SAMPA operates autonomously and can process hundreds of kilometers of radar data picking more than 40 layers. SAMPA final pick results and layer numbering still require a cursory manual adjustment to correct noncontinuous picks, which are likely not annual, and to correct for inconsistency in layer numbering. Despite the manual effort to train and check SAMPA results, it is an efficient tool for picking multiple accumulation layers in polar firn, reducing time over manual digitizing efforts. The trackability of good detected layers is greater than 90%.

  18. Airborne derivation of microburst alerts from ground-based Terminal Doppler Weather Radar information: A flight evaluation

    Science.gov (United States)

    Hinton, David A.

    1993-01-01

    An element of the NASA/FAA windshear program is the integration of ground-based microburst information on the flight deck, to support airborne windshear alerting and microburst avoidance. NASA conducted a windshear flight test program in the summer of 1991 during which airborne processing of Terminal Doppler Weather Radar (TDWR) data was used to derive microburst alerts. Microburst information was extracted from TDWR, transmitted to a NASA Boeing 737 in flight via data link, and processed to estimate the windshear hazard level (F-factor) that would be experienced by the aircraft in each microburst. The microburst location and F-factor were used to derive a situation display and alerts. The situation display was successfully used to maneuver the aircraft for microburst penetrations, during which atmospheric 'truth' measurements were made. A total of 19 penetrations were made of TDWR-reported microburst locations, resulting in 18 airborne microburst alerts from the TDWR data and two microburst alerts from the airborne reactive windshear detection system. The primary factors affecting alerting performance were spatial offset of the flight path from the region of strongest shear, differences in TDWR measurement altitude and airplane penetration altitude, and variations in microburst outflow profiles. Predicted and measured F-factors agreed well in penetrations near microburst cores. Although improvements in airborne and ground processing of the TDWR measurements would be required to support an airborne executive-level alerting protocol, the practicality of airborne utilization of TDWR data link data has been demonstrated.

  19. PC index as a ground-based characteristic for the solar wind energy input into the magnetosphere

    Science.gov (United States)

    Troshichev, Oleg; Stauning, Peter

    The solar wind energy input into the magnetosphere is usually evaluated by power of the magnetic disturbances detected at the Earth and estimated by the AE(AL) and Dst indices, characterizing, correspondingly, the magnetospheric substorm and geomagnetic storm dynamics and intensity. It is generally agreed, however, that the magnetospheric substorms and magnetic storms are the result of release of the energy accumulated by that time in the magnetosphere. Theoretical estimations of the solar wind energy input, making allowance for the actually observed solar wind parameters (for example, -function of Akasofu), turned out impracticable on the reasons of their imperfection and impossibility to organize the reliable monitoring the solar wind parameters in the key points of the space. By now the only PC index is serving as an on-line ground-based indicator of the geoeffective solar wind impact on the magnetosphere. The PC index characterizes the polar cap magnetic activity, generated by the geeffective interplanetary electric field (GIEF). The index is derived by magnetic data of only two stations Thule and Vostok, located in the northern (PCN) and southern (PCS) near-pole regions. The index was put into practice about 25 years ago, but obtained his final design as late as 2006. The unified procedure provides the on-line calculation of the PCN and PCS indices consistent with the GIEF value irrespective of the UT time, season and solar cycle. The proper response of the PC index to actual changes in the interplanetary electric field and the solar wind dynamic pressure is demonstrated. The main attention is given to relationships between the PC index behavior and development of the magnetospheric substorms and geomagnetic storms. It is shown that the magnetospheric substorms intensity and the substorm growth phase duration can be predicted by the PC index growth rate, whereas the geomagnetic storms magnitude and their lenght is indicated by the PC values averaged for the

  20. Ground-Based Global Navigation Satellite System (GNSS) GLONASS Broadcast Ephemeris Data (sub-hourly files) from NASA CDDIS - Cloned

    Data.gov (United States)

    National Aeronautics and Space Administration — This dataset consists of ground-based Global Navigation Satellite System (GNSS) GLObal NAvigation Satellite System (GLONASS) Broadcast Ephemeris Data (sub-hourly...

  1. Ground-Based Global Navigation Satellite System (GNSS) SBAS Broadcast Ephemeris Data (sub-hourly files) from NASA CDDIS

    Data.gov (United States)

    National Aeronautics and Space Administration — This dataset consists of ground-based Global Navigation Satellite System (GNSS) Satellite-Based Augmentation System (SBAS) Broadcast Ephemeris Data (sub-hourly...

  2. Ground-Based Global Navigation Satellite System (GNSS) QZSS Broadcast Ephemeris Data (daily files) from NASA CDDIS

    Data.gov (United States)

    National Aeronautics and Space Administration — This dataset consists of ground-based Global Navigation Satellite System (GNSS) Quasi-Zenith Satellite System (QZSS) Broadcast Ephemeris Data (daily files) from the...

  3. Ground-Based Global Navigation Satellite System (GNSS) Galileo Broadcast Ephemeris Data (sub-hourly files) from NASA CDDIS

    Data.gov (United States)

    National Aeronautics and Space Administration — This dataset consists of ground-based Global Navigation Satellite System (GNSS) Galileo Broadcast Ephemeris Data (sub-hourly files) from the NASA Crustal Dynamics...

  4. Ground-Based Global Navigation Satellite System (GNSS) SBAS Broadcast Ephemeris Data (daily files) from NASA CDDIS

    Data.gov (United States)

    National Aeronautics and Space Administration — This dataset consists of ground-based Global Navigation Satellite System (GNSS) Satellite-Based Augmentation System (SBAS) Broadcast Ephemeris Data (daily files)...

  5. Ground-Based Global Navigation Satellite System (GNSS) GPS Broadcast Ephemeris Data (hourly files) from NASA CDDIS

    Data.gov (United States)

    National Aeronautics and Space Administration — This dataset consists of ground-based Global Navigation Satellite System (GNSS) GPS Broadcast Ephemeris Data (hourly files) from the NASA Crustal Dynamics Data...

  6. Ground-Based Global Navigation Satellite System (GNSS) QZSS Broadcast Ephemeris Data (hourly files) from NASA CDDIS

    Data.gov (United States)

    National Aeronautics and Space Administration — This dataset consists of ground-based Global Navigation Satellite System (GNSS) Quasi-Zenith Satellite System (QZSS) Broadcast Ephemeris Data (hourly files) from the...

  7. Ground-Based Global Navigation Satellite System (GNSS) GPS Broadcast Ephemeris Data (sub-hourly files) from NASA CDDIS

    Data.gov (United States)

    National Aeronautics and Space Administration — This dataset consists of ground-based Global Navigation Satellite System (GNSS) GPS Broadcast Ephemeris Data (sub-hourly files) from the NASA Crustal Dynamics Data...

  8. Ground-Based Global Navigation Satellite System (GNSS) Beidou Broadcast Ephemeris Data (hourly files) from NASA CDDIS

    Data.gov (United States)

    National Aeronautics and Space Administration — This dataset consists of ground-based Global Navigation Satellite System (GNSS) Beidou Broadcast Ephemeris Data (hourly files) from the NASA Crustal Dynamics Data...

  9. Ground-Based Global Navigation Satellite System (GNSS) Galileo Broadcast Ephemeris Data (hourly files) from NASA CDDIS

    Data.gov (United States)

    National Aeronautics and Space Administration — This dataset consists of ground-based Global Navigation Satellite System (GNSS) Galileo Broadcast Ephemeris Data (hourly files) from the NASA Crustal Dynamics Data...

  10. Ground-Based Global Navigation Satellite System (GNSS) Galileo Broadcast Ephemeris Data (daily files) from NASA CDDIS

    Data.gov (United States)

    National Aeronautics and Space Administration — This dataset consists of ground-based Global Navigation Satellite System (GNSS) Galileo Broadcast Ephemeris Data (daily files) from the NASA Crustal Dynamics Data...

  11. Ground-Based Global Navigation Satellite System (GNSS) SBAS Broadcast Ephemeris Data (hourly files) from NASA CDDIS

    Data.gov (United States)

    National Aeronautics and Space Administration — This dataset consists of ground-based Global Navigation Satellite System (GNSS) Satellite-Based Augmentation System (SBAS) Broadcast Ephemeris Data (hourly files)...

  12. Exploring the relationship between monitored ground-based and satellite aerosol measurements over the City of Johannesburg

    CSIR Research Space (South Africa)

    Garland, Rebecca M

    2012-09-01

    Full Text Available This project studied the relationship between aerosol optical depth (AOD) from the Multi-angle Imaging SpectroRadiometer (MISR) instrument on the Terra satellite, and ground-based monitored particulate matter (PM) mass concentrations measured...

  13. Ground-Based Global Navigation Satellite System (GNSS) Observation Data (30-second sampling, hourly files) from NASA CDDIS

    Data.gov (United States)

    National Aeronautics and Space Administration — This dataset consists of ground-based Global Navigation Satellite System (GNSS) Observation Data (30-second sampling, hourly files) from the NASA Crustal Dynamics...

  14. Ground-Based Global Navigation Satellite System (GNSS) QZSS Broadcast Ephemeris Data (sub-hourly files) from NASA CDDIS

    Data.gov (United States)

    National Aeronautics and Space Administration — This dataset consists of ground-based Global Navigation Satellite System (GNSS) Quasi-Zenith Satellite System (QZSS) Broadcast Ephemeris Data (sub-hourly files) from...

  15. Ground-Based Global Navigation Satellite System (GNSS) Beidou Broadcast Ephemeris Data (sub-hourly files) from NASA CDDIS

    Data.gov (United States)

    National Aeronautics and Space Administration — This dataset consists of ground-based Global Navigation Satellite System (GNSS) Beidou Broadcast Ephemeris Data (sub-hourly files) from the NASA Crustal Dynamics...

  16. Ground-Based Global Navigation Satellite System Observation Summary Data (30-second sampling, daily files) from NASA CDDIS

    Data.gov (United States)

    National Aeronautics and Space Administration — This dataset consists of ground-based Global Navigation Satellite System (GNSS) Observation Summary Data (30-second sampling, daily files of all distinct navigation...

  17. Ground-Based Global Navigation Satellite System (GNSS) GPS Broadcast Ephemeris Data (daily files) from NASA CDDIS

    Data.gov (United States)

    National Aeronautics and Space Administration — This dataset consists of ground-based Global Navigation Satellite System (GNSS) GPS Broadcast Ephemeris Data (daily files) from the NASA Crustal Dynamics Data...

  18. Ground-Based Global Navigation Satellite System Mixed Broadcast Ephemeris Data (sub-hourly files) from NASA CDDIS

    Data.gov (United States)

    National Aeronautics and Space Administration — This dataset consists of ground-based Global Navigation Satellite System (GNSS) Mixed Broadcast Ephemeris Data (sub-hourly files) from the NASA Crustal Dynamics Data...

  19. Information Technology Management: Select Controls for the Information Security of the Ground-Based Midcourse Defense Communications Network

    National Research Council Canada - National Science Library

    Truex, Kathryn M; Lamar, Karen J; Leighton, George A; Woodruff, Courtney E; Brunetti, Tina N; Russell, Dawn M

    2006-01-01

    ... to the Ground-Based Midcourse Defense Communications Network should read this report to reduce the risk of interruption, misuse, modification, and unauthorized access to information in the system...

  20. Justifying a Set of Basic Characteristics of High Temperature Cold Accumulators in Their Designing for the Ground-Based Systems

    OpenAIRE

    E. S. Khromov; O. P. Matveeva

    2015-01-01

    The ground-based systems use a wide variety of heat-emitting equipment. For temperature control of equipment and facilities, the thermal management systems (TMS) are included in the ground-based systems. However, in operation, the off-nominal situations with increased heat emission are possible. To avoid overheating of equipment or environment in facilities, where equipment is placed, is possible through completing a set of TMS by high-temperature cold accumulators (CA).When filling CA by the...

  1. The Network for the Detection of Atmospheric Composition Change (NDACC): history, status and perspectives

    Science.gov (United States)

    De Mazière, Martine; Thompson, Anne M.; Kurylo, Michael J.; Wild, Jeannette D.; Bernhard, Germar; Blumenstock, Thomas; Braathen, Geir O.; Hannigan, James W.; Lambert, Jean-Christopher; Leblanc, Thierry; McGee, Thomas J.; Nedoluha, Gerald; Petropavlovskikh, Irina; Seckmeyer, Gunther; Simon, Paul C.; Steinbrecht, Wolfgang; Strahan, Susan E.

    2018-04-01

    The Network for the Detection of Atmospheric Composition Change (NDACC) is an international global network of more than 90 stations making high-quality measurements of atmospheric composition that began official operations in 1991 after 5 years of planning. Apart from sonde measurements, all measurements in the network are performed by ground-based remote-sensing techniques. Originally named the Network for the Detection of Stratospheric Change (NDSC), the name of the network was changed to NDACC in 2005 to better reflect the expanded scope of its measurements. The primary goal of NDACC is to establish long-term databases for detecting changes and trends in the chemical and physical state of the atmosphere (mesosphere, stratosphere, and troposphere) and to assess the coupling of such changes with climate and air quality. NDACC's origins, station locations, organizational structure, and data archiving are described. NDACC is structured around categories of ground-based observational techniques (sonde, lidar, microwave radiometers, Fourier-transform infrared, UV-visible DOAS (differential optical absorption spectroscopy)-type, and Dobson-Brewer spectrometers, as well as spectral UV radiometers), timely cross-cutting themes (ozone, water vapour, measurement strategies, cross-network data integration), satellite measurement systems, and theory and analyses. Participation in NDACC requires compliance with strict measurement and data protocols to ensure that the network data are of high and consistent quality. To widen its scope, NDACC has established formal collaborative agreements with eight other cooperating networks and Global Atmosphere Watch (GAW). A brief history is provided, major accomplishments of NDACC during its first 25 years of operation are reviewed, and a forward-looking perspective is presented.

  2. Detecting math problem solving strategies: an investigation into the use of retrospective self-reports, latency and fMRI data.

    Science.gov (United States)

    Tenison, Caitlin; Fincham, Jon M; Anderson, John R

    2014-02-01

    This research explores how to determine when mathematical problems are solved by retrieval versus computation strategies. Past research has indicated that verbal reports, solution latencies, and neural imaging all provide imperfect indicators of this distinction. Participants in the current study solved mathematical problems involving two distinct problem types, called 'Pyramid' and 'Formula' problems. Participants were given extensive training solving 3 select Pyramid and 3 select Formula problems. Trained problems were highly practiced, whereas untrained problems were not. The distinction between untrained and trained problems was observed in the data. Untrained problems took longer to solve, more often used procedural strategies and showed a greater activation in the horizontal intraparietal sulcus (HIPS) when compared to trained problems. A classifier fit to the neural distinction between trained-untrained problems successfully predicted training within and between the two problem types. We employed this classifier to generate a prediction of strategy use. By combining evidence from the classifier, problem solving latencies, and retrospective reports, we predicted the strategy used to solve each problem in the scanner and gained unexpected insight into the distinction between different strategies. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. Design-considerations For A Ground-based Transit Survey To Find Habitable Planets Around L And T Dwarfs

    Science.gov (United States)

    Tata, Ramarao; Martin, E.

    2011-09-01

    Detection of planets in the habitable zone is one of the key drivers of the exoplanet science community. We present a detailed strategy for such detection around L and T dwarfs. We plan to implement the outcome of the analysis as a transit survey to search for planets around known L and T dwarfs. Understanding of the variability of these cool objects will be a worth-while byproduct of such a survey.

  4. [In vitro immunization for the production of antibodies to tetanus toxin and toxoid. 1. Systems for the detection of in vitro synthetized specific immunoglobulins. Strategies of test development].

    Science.gov (United States)

    Kiessig, S T; Jahn, S; Porstmann, T; von Baehr, R

    1987-01-01

    By means of semipurified tetanus toxin for solid phase coating in an enzyme immunoassay (ELISA) for detection of specific IgG and IgM antibodies a detection limit of 0.02 IU per litre was achieved. The addition of serum from animals like horses or goats as inert protein to the dilution medium was omitted to prevent a displacement of human antibodies by antitetanus antibodies present in the animals sera. The specificity of the ELISA was demonstrated by inhibition experiments with soluble antigen and in an ELISA for detection of anti-tetanus toxin antibodies from mice immunized with the toxoid from the different purification steps.

  5. Time-series of biomass burning products from ground-based FTIR measurements at Reunion Island (21°S, 55°E) and comparisons with the CTM IMAGES

    Science.gov (United States)

    Vigouroux, Corinne; de Mazière, Martine; Dils, Bart; Müller, Jean-François; Senten, Cindy; Stavrakou, Trissevgeni; Vanhaelewyn, Gauthier; Fally, Sophie; Duflot, Valentin; Baray, Jean-Luc

    2010-05-01

    Reunion Island (21°S, 55°E) is part of the Network for the Detection of Atmospheric Composition Change (NDACC), a network dedicated to performing high-quality long-term ground-based observations of atmospheric trace gases at globally distributed sites. Up to now, only a few NDACC stations are located in the Southern Hemisphere, and particularly very few at tropical and subtropical latitudes. Furthermore, Reunion Island is situated in the Indian Ocean, at 2000 km from southeast Africa and at only 700 km from Madagascar. It is therefore a good location to study the transport of biomass burning products from these regions to Reunion Island. Ground-based Fourier transform infrared (FTIR) solar absorption observations are sensitive to a large number of biomass burning products. At present, we have a record of such FTIR observations at Reunion Island from three measurement campaigns, namely in October 2002, from August to October 2004, and from May to October 2007, and from continuous observations that started in May 2009. The measurements in 2007 and 2009-2010 allow the observation of seasonal variability. In this work, we present retrieved time-series of several biomass burning products such as C2H2, C2H6 and HCN. These ground-based data are compared to the CTM IMAGES. The Lagrangian particle dispersion model FLEXPART is used to explain the day-to-day variability of these species by the transport pathways.

  6. Understanding conduit dynamics and forecasting major strombolian explosions by ground-based radar interferometry

    Science.gov (United States)

    Di Traglia, F.; Del Ventisette, C.; Rosi, M.; Mugnai, F.; Intrieri, E.; Moretti, S.; Casagli, N.

    2012-04-01

    Volcanic eruptions are preceded by a series of detectable phenomena related to: i) rise of magma and gas from deep, dike-filling intrusions, ii) increase in magma pressures within conduits, iii) inflation of volcanic edifices.. Ground deformation resulting from volcano inflation can be recorded by various techniques as the recent ground-based radar interferometry (GB-InSAR). Here we present GB-InSAR deformation data (interferograms) collected at Stromboli volcano (Aeolian Islands, Southern Italy) over the period 2008-2011 to evidence that increase in deformation rate in the upper portion of the conduit system occurred before the onset of the very hazardous, "non-forecastable" "major" explosions. "Major" explosions are high-intensity "variation on the Strombolian theme" and, until now, little precursors have been identified. At Stromboli they often occurr clustered within a short time period characterized by "anomalous" activity, that we define as "major-explosions dominated" period. During this phase, the enhanced explosive activity is often associated with lava emissions from the summit craters, and "ordinary" Strombolian activity appears more vigorous and frequent. Medium, short and very-short term interferograms of the summit crater area of Stromboli,revealed increased patterns of deformation rate of the vent areas prior the onset of major explosions. Both the base and the rim of the craters area are the involved in the deformation, with different timing before the occurrence of major explosive events. At the base of the crater, corresponding to the intersection of the summit area with the northern tip of the NE-SW trending dike-conduit, an increase in deformation rate is observed, starting from one week to one month before the onset of a major-explosions dominated period., At the crater rim an increase from high to very high deformation rate is shown about ten to twenty minutes and twenty to forty seconds before each major explosion. We propose that the

  7. Simultaneous detection of decidual Th1/Th2 and NK1/NK2 immunophenotyping in unknown recurrent miscarriage using 8-color flow cytometry with FSC/Vt extended strategy.

    Science.gov (United States)

    Dong, Peng; Wen, Xi; Liu, Jia; Yan, Cui-Yan; Yuan, Jing; Luo, Lan-Rong; Hu, Qiao-Fei; Li, Jian

    2017-06-30

    Th1/Th2 imbalance is considered as a mechanism for recurrent miscarriage. The NK1/NK2 paradigm is hypothesised to play an important role in pregnancy. However, few results showed simultaneous changes of these subsets in vivo in decidual tissues. The present study aimed to detect the decidual mononuclear cells (dMo), and the Th1/Th2, and NK1/NK2 paradigm simultaneously using multiparametric flow cytometry (MFC) in unexplained recurrent miscarriages (URM). Mononuclear cells were isolated from the decidual tissues of URM cases and early pregnant women. The mononuclear cell percent was demonstrated by detecting the expression of CD3, CD4, CD8, CD56, and CD16 extracellular markers, interferon (IFN)-γ, and interleukin (IL)-4 intracellular markers in live cells using 8-color flow cytometry with forward scatter (FSC)/side scatter (SSC) and FSC/viability (Vt) initial gating strategies, and the ratios of Th1/Th2 and decidual NK1 (dNK1)/decidual NK2 (dNK2) cells were compared between the subject groups. Two initial gating strategies of the FSC/SSC or FSC/Vt, with central or extended gating scales, were adapted, and there was no main effect or interaction for the cell proportions, except for the type 1 and type 2 subsets in the FSC/Vt extended gating strategy. There was no significant difference of the proportions of the decidual T, dNK, NKT-like, Th, and Tc cells between the two groups. However, the Th1/Th2 and dNK1/dNK2 ratios in the URM patients were higher compared with the normal group when using the FSC/Vt extended gating strategy. The present study provides means to detect Th1/Th2 and dNK1/dNK2 simultaneously in URM patients for large sample investigations in the future. © 2017 The Author(s).

  8. VIII. The observational strategy: What are the issues; What must be done?

    Energy Technology Data Exchange (ETDEWEB)

    Canavan, G.H.

    1997-03-01

    Throughout its development, the observational strategy of the Earth Observing System (EOS) and its precursor programs has been consistent with that of the Mission to Planet Earth (MTPE) to detect and quantify climate change, document natural climate variability, understand variation and change, determine the causes and impacts of stratospheric ozone depletion, determine the impact of change on ecosystems and mitigate them. Space based observation can contribute significantly to each of these objectives, although its contribution will have to be carefully integrated with aircraft, in situ, international and other contributions and carefully transitioned to long-term operational observations to achieve its maximum potential impact. The interaction between space ad in situ can be in calibration, in interpretation, or in suggesting ways to make important new measurements from space. In atmospheric chemistry is largely involves calibration and global surveys. In ecosystems it involves calibration of EOS and improved sensors. In seasonal to interannual change it involves the testing and calibration of new sensors. In decadal to century change it requires the invention of new sensors. These roles are complementary and reinforcing. Taking full advantage of the synergisms and tradeoffs between space- and ground-based measurements is a potential vehicle for major savings in what is effectively a constant resource program. This paper presents a discussion of the principles guiding the space-based observational strategy, and the interplay between spaced-based and in situ measurements. The paper then discusses international issues, how they might be addressed, and integrated space-based observational strategy.

  9. Yield and quality prediction using satellite passive imagery and ground-based active optical sensors in sugar beet, spring wheat, corn, and sunflower

    Science.gov (United States)

    Bu, Honggang

    Remote sensing is one possible approach for improving crop nitrogen use efficiency to save fertilizer cost, reduce environmental pollution, and improve crop yield and quality. Feasibility and potential of using remote sensing tools to predict crops yield and quality as well as detect nitrogen requirements, application timing, rate, and places in season were investigated based on 2012-2013 two-year and four-crop (corn, spring wheat, sugar beet, and sunflower) study. Two ground-based active optical sensors, GreenSeeker and Holland Scientific Crop Circle, and the RapidEye satellite imagery were used to collect sensing data. Highly significant statistical relationships between INSEY (NDVI normalized by growing degree days) and crop yield and quality indices were found for all crops, indicating that remote sensing tools may be useful for managing in-season crop yield and quality prediction.

  10. Coordinated ground-based, low altitude satellite and Cluster observations on global and local scales during a transient post-noon sector excursion of the magnetospheric cusp

    DEFF Research Database (Denmark)

    Opgenoorth, H.J.; Lockwood, M.; Alcayde, D.

    2001-01-01

    in Canada, Greenland and Scandinavia. After an initial eastward and later poleward expansion of the flow-channel between 13:20 and 13:40 UT, the four Cluster spacecraft, and the field line footprints covered by the eastward looking scan cycle of the Sondre Stromfjord incoherent scatter radar were engulfed...... by cusp-like precipitation with transient magnetic and electric field signatures. In addition, the EISCAT Svalbard Radar detected strong transient effects of the convection reorganisation, a poleward moving precipitation, and a fast ion flow-channel in association with the auroral structures that suddenly...... of the high-latitude dayside convection pattern accurred after 13:20 UT most likely caused by a direction change of the Solar wind magnetic field. The result was an eastward and poleward directed flow-channel, as monitored by the SuperDARN radar network and also by arrays of ground-based magnetometers...

  11. Quality assessment of ground-based microwave measurements of chlorine monoxide, ozone, and nitrogen dioxide from the NDSC radiometer at the Plateau de Bure

    Directory of Open Access Journals (Sweden)

    P. Ricaud

    2004-06-01

    Full Text Available A ground-based microwave radiometer dedicated to chlorine monoxide (ClO measurements around 278GHz has been in operation from December 1993-June 1996 at the Plateau de Bure, France (45° N, 5.9° E, 2500m altitude. It belongs to the international Network for the Detection of Stratospheric Change. A detailed study of both measurements and retrieval schemes has been undertaken. Although dedicated to the measurements of ClO, simultaneous profiles of O3, ClO and NO2, together with information about the instrumental baseline, have been retrieved using the optimal estimation method. The vertical profiles have been compared with other ground-based microwave data, satellite-borne data and model results. Data quality shows: 1 the weak sensitivity of the instrument that obliges to make time averages over several hours; 2 the site location where measurements of good opacities are possible for only a few days per year; 3 the baseline undulation affecting all the spectra, an issue common to all the microwave instruments; 4 the slow drift of some components affecting frequencies by 3-4MHz within a couple of months. Nevertheless, when temporally averaging data over a few days, ClO temporal variations (diurnal and over several weeks in winter 1995 from 35-50km are consistent with model results and satellite data, particularly at the peak altitude around 40km, although temporal coincidences are infrequent in winter 1995. In addition to ClO, it is possible to obtain O3 information from 30-60km whilst the instrument is not optimized at all for this molecule. Retrievals of O3 are reasonable when compared with model and another ground-based data set, although the lowermost layers are affected by the contamination of baseline remnants. Monthly-averaged diurnal variations of NO2 are detected at 40km and appear in agreement with photochemical model results and satellite zonally-averaged data, although the amplitude

  12. Optimal Monitoring Strategy to Detect Rule-breaking: A Power and Simulation Approach Parameterised with Field Data from Gola Rainforest National Park, Sierra Leone

    Directory of Open Access Journals (Sweden)

    Sorrel Jones

    2017-01-01

    Full Text Available Protected area designation aims to protect forests from illegal activities such as hunting. However, the effectiveness of protection and how this changes over time in response to protection measures is difficult to assess, including the design of monitoring programmes able to detect changes. We present new data on rule-breaking prevalence in Gola Rainforest National Park, Sierra Leone, and use these data in spatially explicit simulations to assess the survey effort and design required to detect change and assess the effect of rule-breaker behaviour to these designs. Despite being a protected area, rule-breaking (in the form of signs of hunting occurred in almost 70% of 1 km survey squares but repeating this baseline survey of 53 survey squares would be insufficient to detect change. A much larger survey effort of 200-400 survey squares would be required to detect a 25% change in rule-breaking. Simulations highlight the extent to which rule-breaker behaviour, particularly hunter range size, influenced the likelihood of detecting change and importance of understanding this for survey design. A dedicated monitoring programme able to detect changes in the level of rule-breaking required an unrealistic level of resources, and we recommend combining monitoring with ranger patrol activities to reduce overall costs and employing questionnaire-based methods.

  13. Do Consonant Sonority and Status Influence Syllable-Based Segmentation Strategies in a Visual Letter Detection Task? Developmental Evidence in French Children

    Science.gov (United States)

    Maionchi-Pino, Norbert; de Cara, Bruno; Ecalle, Jean; Magnan, Annie

    2012-01-01

    This article queries whether consonant sonority (sonorant vs. obstruent) and status (coda vs. onset) within intervocalic clusters influence syllable-based segmentation strategies. We used a modified version of the illusory conjunction paradigm to test whether French beginning, intermediate, and advanced readers were sensitive to an optimal…

  14. Strategy for Extracting DNA from Clay Soil and Detecting a Specific Target Sequence via Selective Enrichment and Real-Time (Quantitative) PCR Amplification ▿

    Science.gov (United States)

    Yankson, Kweku K.; Steck, Todd R.

    2009-01-01

    We present a simple strategy for isolating and accurately enumerating target DNA from high-clay-content soils: desorption with buffers, an optional magnetic capture hybridization step, and quantitation via real-time PCR. With the developed technique, μg quantities of DNA were extracted from mg samples of pure kaolinite and a field clay soil. PMID:19633108

  15. Toward High Altitude Airship Ground-Based Boresight Calibration of Hyperspectral Pushbroom Imaging Sensors

    Directory of Open Access Journals (Sweden)

    Aiwu Zhang

    2015-12-01

    Full Text Available The complexity of the single linear hyperspectral pushbroom imaging based on a high altitude airship (HAA without a three-axis stabilized platform is much more than that based on the spaceborne and airborne. Due to the effects of air pressure, temperature and airflow, the large pitch and roll angles tend to appear frequently that create pushbroom images highly characterized with severe geometric distortions. Thus, the in-flight calibration procedure is not appropriate to apply to the single linear pushbroom sensors on HAA having no three-axis stabilized platform. In order to address this problem, a new ground-based boresight calibration method is proposed. Firstly, a coordinate’s transformation model is developed for direct georeferencing (DG of the linear imaging sensor, and then the linear error equation is derived from it by using the Taylor expansion formula. Secondly, the boresight misalignments are worked out by using iterative least squares method with few ground control points (GCPs and ground-based side-scanning experiments. The proposed method is demonstrated by three sets of experiments: (i the stability and reliability of the method is verified through simulation-based experiments; (ii the boresight calibration is performed using ground-based experiments; and (iii the validation is done by applying on the orthorectification of the real hyperspectral pushbroom images from a HAA Earth observation payload system developed by our research team—“LanTianHao”. The test results show that the proposed boresight calibration approach significantly improves the quality of georeferencing by reducing the geometric distortions caused by boresight misalignments to the minimum level.

  16. Retrieval and analysis of atmospheric XCO2 using ground-based spectral observation.

    Science.gov (United States)

    Qin, Xiu-Chun; Lei, Li-Ping; Kawasaki, Masahiro; Masafumi, Ohashi; Takahiro, Kuroki; Zeng, Zhao-Cheng; Zhang, Bing

    2014-07-01

    Atmospheric CO2 column concentration (column-averaged dry air mole fractions of atmospheric carbon dioxide) data obtained by ground-based hyperspectral observation is an important source of data for the verification and improvement of the results of CO2 retrieval based on satellite hyperspectral observation. However, few studies have been conducted on atmospheric CO2 column concentration retrieval based on ground-based spectral hyperspectral observation in China. In the present study, we carried out the ground-based hyperspectral observation in Xilingol Grassland, Inner Mongolia of China by using an observation system which is consisted of an optical spectral analyzer, a sun tracker, and some other elements. The atmospheric CO2 column concentration was retrieved using the observed hyperspectral data. The effect of a wavelength shift of the observation spectra and the meteorological parameters on the retrieval precision of the atmospheric CO2 concentration was evaluated and analyzed. The results show that the mean value of atmospheric CO2 concentration was 390.9 microg x mL(-1) in the study area during the observing period from July to September. The shift of wavelength in the range between -0.012 and 0.042 nm will generally lead to 1 microg x mL(-1) deviation in the CO2 retrievals. This study also revealed that the spectral transmittance was sensitive to meteorological parameters in the wavelength range of 6 357-6 358, 6 360-6 361, and 6 363-6 364 cm(-1). By comparing the CO2 retrievals derived from the meteorological parameters observed in synchronous and non-synchronous time, respectively, with the spectral observation, it was showed that the concentration deviation caused by using the non-synchronously observed meteorological parameters is ranged from 0.11 to 4 microg x mL(-1). These results can be used as references for the further improvement of retrieving CO2 column concentration based on spectral observation.

  17. Specifying the Earth's Plasmasphere With Data Assimilation of Ground-Based Field-Line Resonance Measurements

    Science.gov (United States)

    Jorgensen, Anders; McCarthy, Nicholas; Rivera, Samuell; Ober, Daniel; Zesta, Eftyhia; Chi, Peter; Moldwin, Mark; Ridley, Aaron

    The plasmasphere is an important medium for propagation of the waves which contribute to the decay and acceleration of energetic particles in the radiation belts and ring current. Accurate knowledge of the plasmasphere evolution is important for accurately predicting the evolution of the energetic particle populations. A variety of routine measurements provide information about the plasmasphere, including ground-based and space-based magnetic field-line resonance measurements, space based in-situ plasma density measurements, whistler wave measurements, TEC measurements from GPS receivers, and in some cases global EUV images. Combining these measurements with a physics-based model through a data assimilation scheme should, in principle, allow a better specification of the plasmasphere. Other information which can be used include information about the global magnetic and electric fields from a combination of measurements and models, for example AMIE. In this presentation we will discuss modeling the plasmasphere using these data. A particular advantage of ground-based measurements over space-based measurements are the longevity of the magnetometer and VLF stations, the potentially greater simultaneous coverage in local time and L-shell (as opposed to single-point satellite measurements), and the lower cost of maintaining the networks. In this paper we will explore using a network of ground-based magnetometers to constrain the evolution of the plas-masphere through a data assimilation scheme. We will use the Ober et al. [1997] plasmasphere model, a particle filter data assimilation scheme, and simulated or actual field-line resonance measurements from the McMAC, MEASURE, SAMBA, and CARISMA, magnetometer arrays.

  18. The Virgo 3 km interferometer for gravitational wave detection

    NARCIS (Netherlands)

    Acernese, F.; Amico, Paolo; Alshourbagy, Mohamed; Antonucci, Federica; Aoudia, S.; Astone, P.; Avino, Saverio; Baggio, L.; Ballardin, G.; Barone, F.; Barsotti, L.; Barsuglia, M.; Bauer, Th. S.; Bigotta, Stefano; Bizouard, M. A.; Boccara, Albert-Claude; Bondu, F.; Bosi, Leone; Bradaschia, C.; van den Brand, J. F. J.; Birindelli, Simona; Braccini, Stefano; Brillet, A.; Brisson, V.; Buskulic, D.; Cagnoli, G.; Calloni, E.; Campagna, Enrico; Carbognani, F.; Cavalier, F.; Cavalieri, R.; Cella, G.; Cesarini, E.; Chassande-Mottin, E.; Clapson, A-C; Cleva, F.; Coccia, E.; Corda, C.; Corsi, A.; Cottone, F.; Coulon, J. -P.; Cuoco, E.; D'Antonio, S.; Dari, A.; Dattilo, V.; Davier, M.; Del Prete, M.; Rosa, R.; Di Fiore, L.; Di Lieto, A.; Di Virgilio, A.; Dujardin, B.; Evans, M.; Fafone, V.; Ferrante, I.; Fidecaro, F.; Fiori, I.; Flaminio, R.; Fournier, J. -D.; Frasca, S.; Frasconi, F.; Gammaitoni, L.; Garufi, F.; Genin, E.; Gennai, A.; Giazotto, A.; Giordano, L.; Granata, V.; Greverie, C.; Grosjean, D.; Guidi, G.; Hamdani, S.U.; Hebri, S.; Heitmann, H.; Hello, P.; Huet, D.; Kreckelbergh, S.; La Penna, P.; Laval, M.; Leroy, N.; Letendre, N.; Lopez, B.; Lorenzini, M.; Loriette, V.; Losurdo, G.; Mackowski, J. -M.; Majorana, E.; Man, C. N.; Mantovani, M.; Marchesoni, F.; Marion, F.; Marque, J.; Martelli, F.; Masserot, A.; Menzinger, F.; Milano, L.; Minenkov, Y.; Moins, C.; Moreau, J.; Morgado, N.; Mosca, S.; Mours, B.; Neri, I.; Nocera, F.; Pagliaroli, G.; Pallottino, G. V.; Palomba, C.; Paoletti, F.; Pardi, S.; Pasqualetti, A.; Passaquieti, R.; Passuello, D.; Piergiovanni, F.; Pinard, L.; Poggiani, R.; Punturo, M.; Puppo, P.; van der Putten, S.; Rapagnani, P.; Regimbau, T.; Reita, V.; Remillieux, A.; Ricci, F.; Ricciardi, I.; Rocchi, A.; Romano, R.; Ruggi, P.; Russo, G.; Solimeno, S.; Spallicci, A.; Tarallo, M.; Terenzi, R.; Tonelli, M.; Toncelli, A.; Tournefier, E.; Travasso, F.; Tremola, C.; Vajente, G.; Verkindt, D.; Vetrano, F.; Vicere, A.; Vinet, J. -Y.; Vocca, H.; Yvert, M.

    Virgo, designed, constructed and developed by the French-Italian VIRGO collaboration located in Cascina (Pisa, Italy) and aiming to detect gravitational waves, is a ground-based power recycled Michelson inter