Sample records for aatsr dual view

  1. AATSR Based Volcanic Ash Plume Top Height Estimation

    NASA Astrophysics Data System (ADS)

    Virtanen, Timo H.; Kolmonen, Pekka; Sogacheva, Larisa; Sundstrom, Anu-Maija; Rodriguez, Edith; de Leeuw, Gerrit

    2015-11-01

    The AATSR Correlation Method (ACM) height estimation algorithm is presented. The algorithm uses Advanced Along Track Scanning Radiometer (AATSR) satellite data to detect volcanic ash plumes and to estimate the plume top height. The height estimate is based on the stereo-viewing capability of the AATSR instrument, which allows to determine the parallax between the satellite's nadir and 55◦ forward views, and thus the corresponding height. AATSR provides an advantage compared to other stereo-view satellite instruments: with AATSR it is possible to detect ash plumes using brightness temperature difference between thermal infrared (TIR) channels centered at 11 and 12 μm. The automatic ash detection makes the algorithm efficient in processing large quantities of data: the height estimate is calculated only for the ash-flagged pixels. Besides ash plumes, the algorithm can be applied to any elevated feature with sufficient contrast to the background, such as smoke and dust plumes and clouds. The ACM algorithm can be applied to the Sea and Land Surface Temperature Radiometer (SLSTR), scheduled for launch at the end of 2015.

  2. AATSR - Precise Sea-Surface Temperature for Climate Monitoring and for Operational Applications

    NASA Astrophysics Data System (ADS)

    Llewellyn-Jones, David; Corlett, Gary; Donlon, Craig; Stark, John

    The Advanced Along-Track Scanning Radiometer (AATSR) is an imaging radiometer specifi- cally designed to measure Sea-Surface Temperature (SST) to the demanding levels of accuracy and stability required for climate research. AATSR, which has been operating continuously on ESA's Envisat Satellite since its launch in 2002, achieves the required levels of accuracy on account of its unique dual view, whereby each terrestrial scene is viewed twice, once at nadir and then through an inclined path which uses a different atmospheric path-length, thereby providing a direct observation of atmospheric effects, leading to an exceptionally accurate atmospheric correction. This feature is accompanied by an advanced calibration system combined with excellent optical and thermal designs. Recent rigorous and extensive comparisons with in situ data have shown that, for most of the global oceans, AATSR can achieve and accuracy of around 0.2o C with high stability, which has qualified them for use in climate analysis schemes. Because AATSR is the third sensor in a near-continuous series which started with the launch of ATSR-1 on ERS-1 satellite in 1991, there is a time-series of 16+ years of climate standard SSTs which have recently been re-processed and are now becoming available to the World-wide user community from data centres in Europe. SST data from AATSR have been included in the suite of operational SST products generated by the GODAE/GHRSST Pilot Project, on a timescale needed by operational users and in a format which allows easy ingestion and error estimates for data from AATSR and most of the other sensors currently providing SST measurements from space. Within the GODAE/GHRSST data-products, AATSR SST data are generally regarded as the benchmark for accuracy and are used to provide bias corrections for data from the other sensors, which often have superior coverage, thus exploiting synergistically the complementary qualities if the different data-sets. The UK Met Office

  3. Validation of the AATSR L2 GSST product with in situ measurements from the M-AERI

    NASA Astrophysics Data System (ADS)

    Noyes, E.; Minnett, P.; Remedios, J.; Mannerings, B.; Corlett, G.; Edwards, M.; Llewellyn-Jones, D.

    Precise, in situ, measurements of skin Sea Surface Temperature (SSST) have been obtained over the Eastern Caribbean Sea, using the Marine Atmospheric Emitted Radiance Interferometer (M-AERI) deployed onboard the Explorer of the Seas cruise ship. These measurements provide a near-continuous SSST dataset and have been used to validate the Advanced Along-Track Scanning Radiometer (AATSR) Level 2 operational dual-view Gridded Sea Surface Temperature (GSST) product over the area. The (A)ATSR instrument has a unique design in that it has both a nadir- and forward-view, allowing the Earth's surface to be viewed along two different atmospheric path lengths and enabling an improved atmospheric correction to be made when retrieving measurements of SST. The infrared radiometer also uses an innovative and exceptionally stable on-board calibration system, which, together with actively cooled detectors, gives exceptionally high radiometric sensitivity and precision, enabling SSTs to be retrieved to within ± 0.3 K (1-sigma limit). The unprecedented number of measurements provided by the M-AERI project enables us to validate the AATSR SST products on a scale that has not been possible with its two predecessors, ATSR-1 and ATSR-2. Validation results obtained between September 2002 and September 2003 are presented and indicate that, although the AATSR appears to measure slightly warm (circa + 0.14 K), the GSST product is accurate to within 0.28-0.41 K (Root Mean Square difference) in this geographical region, depending on the validation criteria used. We also present the results of further investigations into a number of validation points that do not fall within the target ± 0.3 K accuracy zone.

  4. A sea surface reflectance model for (A)ATSR, and application to aerosol retrievals

    NASA Astrophysics Data System (ADS)

    Sayer, A. M.; Thomas, G. E.; Grainger, R. G.

    2010-07-01

    A model of the sea surface bidirectional reflectance distribution function (BRDF) is presented for the visible and near-IR channels (over the spectral range 550 nm to 1.6 μm) of the dual-viewing Along-Track Scanning Radiometers (ATSRs). The intended application is as part of the Oxford-RAL Aerosols and Clouds (ORAC) retrieval scheme. The model accounts for contributions to the observed reflectance from whitecaps, sun-glint and underlight. Uncertainties in the parametrisations used in the BRDF model are propagated through into the forward model and retrieved state. The new BRDF model offers improved coverage over previous methods, as retrievals are possible into the sun-glint region, through the ATSR dual-viewing system. The new model has been applied in the ORAC aerosol retrieval algorithm to process Advanced ATSR (AATSR) data from September 2004 over the south-eastern Pacific. The assumed error budget is shown to be generally appropriate, meaning the retrieved states are consistent with the measurements and a priori assumptions. The resulting field of aerosol optical depth (AOD) is compared with colocated MODIS-Terra observations, AERONET observations at Tahiti, and cruises over the oceanic region. MODIS and AATSR show similar spatial distributions of AOD, although MODIS reports values which are larger and more variable. It is suggested that assumptions in the MODIS aerosol retrieval algorithm may lead to a positive bias in MODIS AOD of order 0.01 at 550 nm over ocean regions where the wind speed is high.

  5. A sea surface reflectance model for (A)ATSR, and application to aerosol retrievals

    NASA Astrophysics Data System (ADS)

    Sayer, A. M.; Thomas, G. E.; Grainger, R. G.

    2010-03-01

    A model of the sea surface bidirectional reflectance distribution function (BRDF) is presented for the visible and near-IR channels (over the spectral range 550 nm to 1.6 μm) of the dual-viewing Along-Track Scanning Radiometers (ATSRs). The intended application is as part of the Oxford-RAL Aerosols and Clouds (ORAC) retrieval scheme. The model accounts for contributions to the observed reflectance from whitecaps, sun-glint and underlight. Uncertainties in the parametrisations used in the BRDF model are propagated through into the forward model and retrieved state. The new BRDF model offers improved coverage over previous methods, as retrievals are possible into the sun-glint region, through the ATSR dual-viewing system. The new model has been applied in the ORAC aerosol retrieval algorithm to process Advanced ATSR (AATSR) data from September 2004 over the south-eastern Pacific. The assumed error budget is shown to be generally appropriate, meaning the retrieved states are consistent with the measurements and a priori assumptions. The resulting field of aerosol optical depth (AOD) is compared with colocated MODIS-Terra observations, AERONET observations at Tahiti, and cruises over the oceanic region. MODIS and AATSR show similar spatial distributions of AOD, although MODIS reports values which are larger and more variable. It is suggested that assumptions in the MODIS aerosol retrieval algorithm may lead to a positive bias in MODIS AOD of order 0.01 at 550 nm over ocean regions where the wind speed is high.

  6. The WATERMED field experiment: validation of the AATSR LST product with in situ measurements

    NASA Astrophysics Data System (ADS)

    Noyes, E.; Soria, G.; Sobrino, J.; Remedios, J.; Llewellyn-Jones, D.; Corlett, G.

    The Advanced Along-Track Scanning Radiometer (AATSR) onboard ESA's Envisat Satellite, is the third in a series of a precision radiometers designed to measure Sea Surface Temperature (SST) with accuracies of better than ± 0.3 K (within 1-sigma limit). Since its launch in March 2001, a prototype AATSR Land Surface Temperature (LST) product has been produced for validation purposes only, with the product becoming operational from mid-2004. The (A)ATSR instrument design is unique in that it has both a nadir- and a forward-view, allowing the Earth's surface to be viewed along two different atmospheric path lengths, thus enabling an improved atmospheric correction to be made when retrieving surface temperature. It also uses an innovative and exceptionally stable on-board calibration system for its infrared channels, which, together with actively cooled detectors, gives extremely high radiometric sensitivity and precision. In this presentation, results from a comparison of the prototype LST product with ground-based measurements obtained at the WATERMED (WATer use Efficiency in natural vegetation and agricultural areas by Remote sensing in the MEDiterranean basin) field site near Marrakech, Morocco, are presented. The comparison shows that the AATSR has a positive bias of + 1.5 K, with a standard deviation of 0.7 K, indicating that the product is operating within the target specification (± 2.5 K) over the WATERMED field site. However, several anomalous validation points were observed during the analysis and we will discuss possible reasons for the occurrence of these data, including their coincidence with the presence of an Envisat blanking pulse (indicating the presence of a radar pulse at the time of AATSR pixel integration). Further investigation into this matter is required as previous investigations have always indicated that the presence of a payload radar pulse does not have any effect on (A)ATSR data quality.

  7. Technical note: Intercomparison of three AATSR Level 2 (L2) AOD products over China

    NASA Astrophysics Data System (ADS)

    Che, Yahui; Xue, Yong; Mei, Linlu; Guang, Jie; She, Lu; Guo, Jianping; Hu, Yincui; Xu, Hui; He, Xingwei; Di, Aojie; Fan, Cheng

    2016-08-01

    One of four main focus areas of the PEEX initiative is to establish and sustain long-term, continuous, and comprehensive ground-based, airborne, and seaborne observation infrastructure together with satellite data. The Advanced Along-Track Scanning Radiometer (AATSR) aboard ENVISAT is used to observe the Earth in dual view. The AATSR data can be used to retrieve aerosol optical depth (AOD) over both land and ocean, which is an important parameter in the characterization of aerosol properties. In recent years, aerosol retrieval algorithms have been developed both over land and ocean, taking advantage of the features of dual view, which can help eliminate the contribution of Earth's surface to top-of-atmosphere (TOA) reflectance. The Aerosol_cci project, as a part of the Climate Change Initiative (CCI), provides users with three AOD retrieval algorithms for AATSR data, including the Swansea algorithm (SU), the ATSR-2ATSR dual-view aerosol retrieval algorithm (ADV), and the Oxford-RAL Retrieval of Aerosol and Cloud algorithm (ORAC). The validation team of the Aerosol-CCI project has validated AOD (both Level 2 and Level 3 products) and AE (Ångström Exponent) (Level 2 product only) against the AERONET data in a round-robin evaluation using the validation tool of the AeroCOM (Aerosol Comparison between Observations and Models) project. For the purpose of evaluating different performances of these three algorithms in calculating AODs over mainland China, we introduce ground-based data from CARSNET (China Aerosol Remote Sensing Network), which was designed for aerosol observations in China. Because China is vast in territory and has great differences in terms of land surfaces, the combination of the AERONET and CARSNET data can validate the L2 AOD products more comprehensively. The validation results show different performances of these products in 2007, 2008, and 2010. The SU algorithm performs very well over sites with different surface conditions in mainland China

  8. The advanced along track scanning radiometer (aatsr) on esa's envisat satellite - an early assessment

    NASA Astrophysics Data System (ADS)

    Llewellyn-Jones, D.; Mutlow, C.; Smith, D.; Edwards, M.

    The AATSR sensor is an imaging radiometer designed to measure top-of-the- atmosphere brightness temperature in seven thermal infrared, reflected infrared and visible wavelength channels. The main objective of the AATSR mission is to generate fields of global sea-surface temperature to the high levels of accuracy required for the monitoring and detection of climate change, and to support a broad range of associated research into the marine, terrestrial, cryospheric and atmospheric environments. An essential component of this objective is maintain continuity with the high-quality data-sets already collected form the two predecessor sensors, ATSR1 and 2 on ESA's ERS-1 and -2 satellites respectively. Following the successful launch of ENVISAT on March 1 2002, the AATSR sensor was activated and systematically brought up to full operating configuration in accordance with the agreed Switch-On and Data Acquisition Plan (SODAP). The early images form AATSR are of a quality that is consistent with its objective of effective data continuity. Since the instrument has been returning data, a programme of quality assessment has been taking place. This has included a systematic assessment of instrumental aspects such as signal-to-noise performance and image stability as well as the initial observations in the AATSR validation programme. In this programme, AATSR data-products are compared with correlative observations from other sources, which include, sea-borne radiometers, meteorological analysis fields and data from other satellites. This paper reports early results from some of the activities.

  9. AATSR: global-change and surface-temperature measurements from Envisat

    NASA Astrophysics Data System (ADS)

    Llewellyn-Jones, D.; Edwards, M. C.; Mutlow, C. T.; Birks, A. R.; Barton, I. J.; Tait, H.

    2001-02-01

    The Advanced Along-Track Scanning Radiometer (AATSR) onboard ESA's Envisat spacecraft is designed to meet the challenging task of monitoring and detecting climate change. It builds on the success of its predecessor instruments on the ERS-1 and ERS-2 satellites, and will lead to a 15+ year record of precise and accurate global Sea-Surface Temperature (SST) measurements, thereby making a valuable contribution to the long-term climate record. With its high-accuracy, high-quality imagery and channels in the visible, near-infrared and thermal wavelengths, AATSR data will support many applications in addition to oceanographic and climate research, including a wide range of land-surface, cryosphere and atmospheric studies.

  10. AATSR land surface temperature product algorithm verification over a WATERMED site

    NASA Astrophysics Data System (ADS)

    Noyes, E. J.; Sòria, G.; Sobrino, J. A.; Remedios, J. J.; Llewellyn-Jones, D. T.; Corlett, G. K.

    A new operational Land Surface Temperature (LST) product generated from data acquired by the Advanced Along-Track Scanning Radiometer (AATSR) provides the opportunity to measure LST on a global scale with a spatial resolution of 1 km2. The target accuracy of the product, which utilises nadir data from the AATSR thermal channels at 11 and 12 μm, is 2.5 K for daytime retrievals and 1.0 K at night. We present the results of an experiment where the performance of the algorithm has been assessed for one daytime and one night time overpass occurring over the WATERMED field site near Marrakech, Morocco, on 05 March 2003. Top of atmosphere (TOA) brightness temperatures (BTs) are simulated for 12 pixels from each overpass using a radiative transfer model, with the LST product and independent emissivity values and atmospheric data as inputs. We have estimated the error in the LST product over this biome for this set of conditions by applying the operational AATSR LST retrieval algorithm to the modelled BTs and comparing the results with the original AATSR LSTs input into the model. An average bias of -1.00 K (standard deviation 0.07 K) for the daytime data, and -1.74 K (standard deviation 0.02 K) for the night time data is obtained, which indicates that the algorithm is yielding an LST that is too cold under these conditions. While these results are within specification for daytime retrievals, this suggests that the target accuracy of 1.0 K at night is not being met within this biome.

  11. Bayesian cloud detection for MERIS, AATSR, and their combination

    NASA Astrophysics Data System (ADS)

    Hollstein, A.; Fischer, J.; Carbajal Henken, C.; Preusker, R.

    2014-11-01

    A broad range of different of Bayesian cloud detection schemes is applied to measurements from the Medium Resolution Imaging Spectrometer (MERIS), the Advanced Along-Track Scanning Radiometer (AATSR), and their combination. The cloud masks were designed to be numerically efficient and suited for the processing of large amounts of data. Results from the classical and naive approach to Bayesian cloud masking are discussed for MERIS and AATSR as well as for their combination. A sensitivity study on the resolution of multidimensional histograms, which were post-processed by Gaussian smoothing, shows how theoretically insufficient amounts of truth data can be used to set up accurate classical Bayesian cloud masks. Sets of exploited features from single and derived channels are numerically optimized and results for naive and classical Bayesian cloud masks are presented. The application of the Bayesian approach is discussed in terms of reproducing existing algorithms, enhancing existing algorithms, increasing the robustness of existing algorithms, and on setting up new classification schemes based on manually classified scenes.

  12. Bayesian cloud detection for MERIS, AATSR, and their combination

    NASA Astrophysics Data System (ADS)

    Hollstein, A.; Fischer, J.; Carbajal Henken, C.; Preusker, R.

    2015-04-01

    A broad range of different of Bayesian cloud detection schemes is applied to measurements from the Medium Resolution Imaging Spectrometer (MERIS), the Advanced Along-Track Scanning Radiometer (AATSR), and their combination. The cloud detection schemes were designed to be numerically efficient and suited for the processing of large numbers of data. Results from the classical and naive approach to Bayesian cloud masking are discussed for MERIS and AATSR as well as for their combination. A sensitivity study on the resolution of multidimensional histograms, which were post-processed by Gaussian smoothing, shows how theoretically insufficient numbers of truth data can be used to set up accurate classical Bayesian cloud masks. Sets of exploited features from single and derived channels are numerically optimized and results for naive and classical Bayesian cloud masks are presented. The application of the Bayesian approach is discussed in terms of reproducing existing algorithms, enhancing existing algorithms, increasing the robustness of existing algorithms, and on setting up new classification schemes based on manually classified scenes.

  13. Cloud property datasets retrieved from AVHRR, MODIS, AATSR and MERIS in the framework of the Cloud_cci project

    NASA Astrophysics Data System (ADS)

    Stengel, Martin; Stapelberg, Stefan; Sus, Oliver; Schlundt, Cornelia; Poulsen, Caroline; Thomas, Gareth; Christensen, Matthew; Carbajal Henken, Cintia; Preusker, Rene; Fischer, Jürgen; Devasthale, Abhay; Willén, Ulrika; Karlsson, Karl-Göran; McGarragh, Gregory R.; Proud, Simon; Povey, Adam C.; Grainger, Roy G.; Fokke Meirink, Jan; Feofilov, Artem; Bennartz, Ralf; Bojanowski, Jedrzej S.; Hollmann, Rainer

    2017-11-01

    New cloud property datasets based on measurements from the passive imaging satellite sensors AVHRR, MODIS, ATSR2, AATSR and MERIS are presented. Two retrieval systems were developed that include components for cloud detection and cloud typing followed by cloud property retrievals based on the optimal estimation (OE) technique. The OE-based retrievals are applied to simultaneously retrieve cloud-top pressure, cloud particle effective radius and cloud optical thickness using measurements at visible, near-infrared and thermal infrared wavelengths, which ensures spectral consistency. The retrieved cloud properties are further processed to derive cloud-top height, cloud-top temperature, cloud liquid water path, cloud ice water path and spectral cloud albedo. The Cloud_cci products are pixel-based retrievals, daily composites of those on a global equal-angle latitude-longitude grid, and monthly cloud properties such as averages, standard deviations and histograms, also on a global grid. All products include rigorous propagation of the retrieval and sampling uncertainties. Grouping the orbital properties of the sensor families, six datasets have been defined, which are named AVHRR-AM, AVHRR-PM, MODIS-Terra, MODIS-Aqua, ATSR2-AATSR and MERIS+AATSR, each comprising a specific subset of all available sensors. The individual characteristics of the datasets are presented together with a summary of the retrieval systems and measurement records on which the dataset generation were based. Example validation results are given, based on comparisons to well-established reference observations, which demonstrate the good quality of the data. In particular the ensured spectral consistency and the rigorous uncertainty propagation through all processing levels can be considered as new features of the Cloud_cci datasets compared to existing datasets. In addition, the consistency among the individual datasets allows for a potential combination of them as well as facilitates studies on the

  14. The accuracy of SST retrievals from AATSR: An initial assessment through geophysical validation against in situ radiometers, buoys and other SST data sets

    NASA Astrophysics Data System (ADS)

    Corlett, G. K.; Barton, I. J.; Donlon, C. J.; Edwards, M. C.; Good, S. A.; Horrocks, L. A.; Llewellyn-Jones, D. T.; Merchant, C. J.; Minnett, P. J.; Nightingale, T. J.; Noyes, E. J.; O'Carroll, A. G.; Remedios, J. J.; Robinson, I. S.; Saunders, R. W.; Watts, J. G.

    The Advanced Along-Track Scanning Radiometer (AATSR) was launched on Envisat in March 2002. The AATSR instrument is designed to retrieve precise and accurate global sea surface temperature (SST) that, combined with the large data set collected from its predecessors, ATSR and ATSR-2, will provide a long term record of SST data that is greater than 15 years. This record can be used for independent monitoring and detection of climate change. The AATSR validation programme has successfully completed its initial phase. The programme involves validation of the AATSR derived SST values using in situ radiometers, in situ buoys and global SST fields from other data sets. The results of the initial programme presented here will demonstrate that the AATSR instrument is currently close to meeting its scientific objectives of determining global SST to an accuracy of 0.3 K (one sigma). For night time data, the analysis gives a warm bias of between +0.04 K (0.28 K) for buoys to +0.06 K (0.20 K) for radiometers, with slightly higher errors observed for day time data, showing warm biases of between +0.02 (0.39 K) for buoys to +0.11 K (0.33 K) for radiometers. They show that the ATSR series of instruments continues to be the world leader in delivering accurate space-based observations of SST, which is a key climate parameter.

  15. A dual-view digital tomosynthesis imaging technique for improved chest imaging

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Zhong, Yuncheng; Lai, Chao-Jen; Wang, Tianpeng

    Purpose: Digital tomosynthesis (DTS) has been shown to be useful for reducing the overlapping of abnormalities with anatomical structures at various depth levels along the posterior–anterior (PA) direction in chest radiography. However, DTS provides crude three-dimensional (3D) images that have poor resolution in the lateral view and can only be displayed with reasonable quality in the PA view. Furthermore, the spillover of high-contrast objects from off-fulcrum planes generates artifacts that may impede the diagnostic use of the DTS images. In this paper, the authors describe and demonstrate the use of a dual-view DTS technique to improve the accuracy of themore » reconstructed volume image data for more accurate rendition of the anatomy and slice images with improved resolution and reduced artifacts, thus allowing the 3D image data to be viewed in views other than the PA view. Methods: With the dual-view DTS technique, limited angle scans are performed and projection images are acquired in two orthogonal views: PA and lateral. The dual-view projection data are used together to reconstruct 3D images using the maximum likelihood expectation maximization iterative algorithm. In this study, projection images were simulated or experimentally acquired over 360° using the scanning geometry for cone beam computed tomography (CBCT). While all projections were used to reconstruct CBCT images, selected projections were extracted and used to reconstruct single- and dual-view DTS images for comparison with the CBCT images. For realistic demonstration and comparison, a digital chest phantom derived from clinical CT images was used for the simulation study. An anthropomorphic chest phantom was imaged for the experimental study. The resultant dual-view DTS images were visually compared with the single-view DTS images and CBCT images for the presence of image artifacts and accuracy of CT numbers and anatomy and quantitatively compared with root-mean-square-deviation (RMSD

  16. Cloud screening and melt water detection over melting sea ice using AATSR/SLSTR

    NASA Astrophysics Data System (ADS)

    Istomina, Larysa; Heygster, Georg

    2014-05-01

    With the onset of melt in the Arctic Ocean, the fraction of melt water on sea ice, the melt pond fraction, increases. The consequences are: the reduced albedo of sea ice, increased transmittance of sea ice and affected heat balance of the system with more heat passing through the ice into the ocean, which facilitates further melting. The onset of melt, duration of melt season and melt pond fraction are good indicators of the climate state of the Arctic and its change. In the absence of reliable sea ice thickness retrievals in summer, melt pond fraction retrieval from satellite is in demand as input for GCM as an indicator of melt state of the sea ice. The retrieval of melt pond fraction with a moderate resolution radiometer as AATSR is, however, a non-trivial task due to a variety of subpixel surface types with very different optical properties, which give non-unique combinations if mixed. In this work this has been solved by employing additional information on the surface and air temperature of the pixel. In the current work, a concept of melt pond detection on sea ice is presented. The basis of the retrieval is the sensitivity of AATSR reflectance channels 550nm and 860nm to the amount of melt water on sea ice. The retrieval features extensive usage of a database of in situ surface albedo spectra. A tree of decisions is employed to select the feasible family of in situ spectra for the retrieval, depending on the melt stage of the surface. Reanalysis air temperature at the surface and brightness temperature measured by the satellite sensor are analyzed in order to evaluate the melting status of the surface. Case studies for FYI and MYI show plausible retrieved melt pond fractions, characteristic for both of the ice types. The developed retrieval can be used to process the historical AATSR (2002-2012) dataset, as well as for the SLSTR sensor onboard the future Sentinel-3 mission (scheduled for launch in 2015), to keep the continuity and obtain longer time sequence

  17. Estimation of the Total Atmospheric Water Vapor Content and Land Surface Temperature Based on AATSR Thermal Data

    PubMed Central

    Zhang, Tangtang; Wen, Jun; van der Velde, Rogier; Meng, Xianhong; Li, Zhenchao; Liu, Yuanyong; Liu, Rong

    2008-01-01

    The total atmospheric water vapor content (TAWV) and land surface temperature (LST) play important roles in meteorology, hydrology, ecology and some other disciplines. In this paper, the ENVISAT/AATSR (The Advanced Along-Track Scanning Radiometer) thermal data are used to estimate the TAWV and LST over the Loess Plateau in China by using a practical split window algorithm. The distribution of the TAWV is accord with that of the MODIS TAWV products, which indicates that the estimation of the total atmospheric water vapor content is reliable. Validations of the LST by comparing with the ground measurements indicate that the maximum absolute derivation, the maximum relative error and the average relative error is 4.0K, 11.8% and 5.0% respectively, which shows that the retrievals are believable; this algorithm can provide a new way to estimate the LST from AATSR data. PMID:27879795

  18. Validation and Comparison of AATRS AOD L2 Products over China

    NASA Astrophysics Data System (ADS)

    Che, Yahui; Xue, Yong; Guang, Jie; Guo, Jianping; Li, Ying

    2016-04-01

    The Advanced Along-Track Scanning Radiometer (AATSR) aboard on ENVISAT has been used to observe the Earth for more than 10 years since than 2002. One of main applications of AATSR instrument is to observe atmospheric aerosol, especially in retrieval of aerosol optical depth (AOD), taking advantage of its dual-view that helps to separate the contribution of aerosol from top of atmosphere reflectance (A. A. Kokhanovsky and de Leeuw, 2009). The project of Aerosol_CCI, as part of European Space Agency's Climate Change Initiative (CCI), has released new AATSR aerosol AOD products by the of 2015, including the SU v4.21 product from Swansea algorithm, ADV v2.3 product from the ATSR-2/AATSR dual view aerosol retrieval algorithm (ADV) and ORAC v03.04 product from the Oxford-RAL Retrieval of Aerosol and Cloud algorithm. The previous versions of these three AOD level 2 (L2) products in 2008 have been validated over mainland China (Che and Xue, 2015). In this paper, we validated these AATSR AOD products with latest versions in mainland China in 2007, 2008 and 2010 by the means of comparison with the AErosol RObotic NETwork (AERONET) and the China Aerosol Remote Sensing Network (CARSNET). The combination of AERONET and CARSNET helps to make up for the disadvantages of small number and uneven distribution of AEROENT cites. The validation results show different performance of these AOD products over China. The performances of SU and ADV products seem to be the same with close correlation coefficient (CC) about 08~0.9 and root mean square (RMS) within 0.15 in all three years, and sensitive to high AOD values (AOD >1): more AODs and more underestimated. However, these two products do exist difference, which is that the SU algorithm retrieves more high AODs, leading to more space-time validation matches with ground-based data. The ORAC algorithm is different from the others, it can be not only used to retrieve low AODs but also high AODs over different landcover types. Even though

  19. Ensembles of satellite aerosol retrievals based on three AATSR algorithms within aerosol_cci

    NASA Astrophysics Data System (ADS)

    Kosmale, Miriam; Popp, Thomas

    2016-04-01

    Ensemble techniques are widely used in the modelling community, combining different modelling results in order to reduce uncertainties. This approach could be also adapted to satellite measurements. Aerosol_cci is an ESA funded project, where most of the European aerosol retrieval groups work together. The different algorithms are homogenized as far as it makes sense, but remain essentially different. Datasets are compared with ground based measurements and between each other. Three AATSR algorithms (Swansea university aerosol retrieval, ADV aerosol retrieval by FMI and Oxford aerosol retrieval ORAC) provide within this project 17 year global aerosol records. Each of these algorithms provides also uncertainty information on pixel level. Within the presented work, an ensembles of the three AATSR algorithms is performed. The advantage over each single algorithm is the higher spatial coverage due to more measurement pixels per gridbox. A validation to ground based AERONET measurements shows still a good correlation of the ensemble, compared to the single algorithms. Annual mean maps show the global aerosol distribution, based on a combination of the three aerosol algorithms. In addition, pixel level uncertainties of each algorithm are used for weighting the contributions, in order to reduce the uncertainty of the ensemble. Results of different versions of the ensembles for aerosol optical depth will be presented and discussed. The results are validated against ground based AERONET measurements. A higher spatial coverage on daily basis allows better results in annual mean maps. The benefit of using pixel level uncertainties is analysed.

  20. 35. VIEW OF DUAL VENTURI GAS WASHER IN THE GAS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    35. VIEW OF DUAL VENTURI GAS WASHER IN THE GAS WASHER PUMP HOUSE LOOKING NORTHEAST. - U.S. Steel Duquesne Works, Basic Oxygen Steelmaking Plant, Along Monongahela River, Duquesne, Allegheny County, PA

  1. Wide field-of-view dual-band multispectral muzzle flash detection

    NASA Astrophysics Data System (ADS)

    Montoya, J.; Melchor, J.; Spiliotis, P.; Taplin, L.

    2013-06-01

    Sensor technologies are undergoing revolutionary advances, as seen in the rapid growth of multispectral methodologies. Increases in spatial, spectral, and temporal resolution, and in breadth of spectral coverage, render feasible sensors that function with unprecedented performance. A system was developed that addresses many of the key hardware requirements for a practical dual-band multispectral acquisition system, including wide field of view and spectral/temporal shift between dual bands. The system was designed using a novel dichroic beam splitter and dual band-pass filter configuration that creates two side-by-side images of a scene on a single sensor. A high-speed CMOS sensor was used to simultaneously capture data from the entire scene in both spectral bands using a short focal-length lens that provided a wide field-of-view. The beam-splitter components were arranged such that the two images were maintained in optical alignment and real-time intra-band processing could be carried out using only simple arithmetic on the image halves. An experiment related to limitations of the system to address multispectral detection requirements was performed. This characterized the system's low spectral variation across its wide field of view. This paper provides lessons learned on the general limitation of key hardware components required for multispectral muzzle flash detection, using the system as a hardware example combined with simulated multispectral muzzle flash and background signatures.

  2. Dual-view-zone tabletop 3D display system based on integral imaging.

    PubMed

    He, Min-Yang; Zhang, Han-Le; Deng, Huan; Li, Xiao-Wei; Li, Da-Hai; Wang, Qiong-Hua

    2018-02-01

    In this paper, we propose a dual-view-zone tabletop 3D display system based on integral imaging by using a multiplexed holographic optical element (MHOE) that has the optical properties of two sets of microlens arrays. The MHOE is recorded by a reference beam using the single-exposure method. The reference beam records the wavefronts of a microlens array from two different directions. Thus, when the display beam is projected on the MHOE, two wavefronts with the different directions will be rebuilt and the 3D virtual images can be reconstructed in two viewing zones. The MHOE has angle and wavelength selectivity. Under the conditions of the matched wavelength and the angle of the display beam, the diffraction efficiency of the MHOE is greatest. Because the unmatched light just passes through the MHOE, the MHOE has the advantage of a see-through display. The experimental results confirm the feasibility of the dual-view-zone tabletop 3D display system.

  3. Dual-mode switching of a liquid crystal panel for viewing angle control

    NASA Astrophysics Data System (ADS)

    Baek, Jong-In; Kwon, Yong-Hoan; Kim, Jae Chang; Yoon, Tae-Hoon

    2007-03-01

    The authors propose a method to control the viewing angle of a liquid crystal (LC) panel using dual-mode switching. To realize both wide viewing angle (WVA) characteristics and narrow viewing angle (NVA) characteristics with a single LC panel, the authors use two different dark states. The LC layer can be aligned homogeneously parallel to the transmission axis of the bottom polarizer for WVA dark state operation, while it can be aligned vertically for NVA dark state operation. The authors demonstrated that viewing angle control can be achieved with a single panel without any loss of contrast at the front.

  4. Reconciling the aerosol-liquid water path relationship in the ECHAM6-HAM GCM and the Aerosol_cci/Cloud_cci (A)ATSR dataset by minimizing the effect of aerosol swelling

    NASA Astrophysics Data System (ADS)

    Neubauer, D.; Christensen, M.; Lohmann, U.; Poulsen, C. A.

    2016-12-01

    Studies using present day variability to assess statistical relationships between aerosol and cloud properties find different strengths of these relationships between satellite data and general circulation model (GCM) data. This discrepancy can be explained by structural uncertainties due to differences in the analysis/observational scale and the process scale or spurious relationships between aerosol and cloud properties. Such spurious relationships are the growth of aerosol particles in the humid environment surrounding clouds, misclassification of partly cloudy satellite pixels as cloud free pixels, brightening of aerosol particles by sunlight reflected at cloud edges, or effects of clouds on aerosol like processing of aerosol particles in clouds by nucleation or impact scavenging and subsequent growth by heterogeneous chemistry and release by cloud droplet evaporation or wet scavenging of aerosol particles. To minimize the effects of spatial aggregation and spurious relationships we apply a new nearest neighbour approach to high resolution (A)ATSR datasets from the Aerosol_cci and Cloud_cci projects of the Climate Change Initiative (CCI) programme of ESA. For the ECHAM6-HAM GCM we quantify the impact of using dry aerosol (without aerosol water) in the analysis to mimic the effect of the nearest neighbour approach. The aerosol-liquid water path relationship in ECHAM6-HAM is systematically stronger than in (A)ATSR data and cannot be explained by an overestimation of autoconversion when using diagnostic precipitation but rather by aerosol swelling in regions where humidity is high and clouds are present. When aerosol water is removed from the analysis in ECHAM6-HAM the strength of the aerosol-liquid water path relationship agrees much better with the ones of (A)ATSR or MODIS. We further find that while the observed relationships of different satellite sensors ((A)ATSR vs. MODIS) are not always consistent for tested environmental conditions the relationships in

  5. Dual-view inverted selective plane illumination microscopy (diSPIM) with improved background rejection for accurate 3D digital pathology

    NASA Astrophysics Data System (ADS)

    Hu, Bihe; Bolus, Daniel; Brown, J. Quincy

    2018-02-01

    Current gold-standard histopathology for cancerous biopsies is destructive, time consuming, and limited to 2D slices, which do not faithfully represent true 3D tumor micro-morphology. Light sheet microscopy has emerged as a powerful tool for 3D imaging of cancer biospecimens. Here, we utilize the versatile dual-view inverted selective plane illumination microscopy (diSPIM) to render digital histological images of cancer biopsies. Dual-view architecture enabled more isotropic resolution in X, Y, and Z; and different imaging modes, such as adding electronic confocal slit detection (eCSD) or structured illumination (SI), can be used to improve degraded image quality caused by background signal of large, scattering samples. To obtain traditional H&E-like images, we used DRAQ5 and eosin (D&E) staining, with 488nm and 647nm laser illumination, and multi-band filter sets. Here, phantom beads and a D&E stained buccal cell sample have been used to verify our dual-view method. We also show that via dual view imaging and deconvolution, more isotropic resolution has been achieved for optical cleared human prostate sample, providing more accurate quantitation of 3D tumor architecture than was possible with single-view SPIM methods. We demonstrate that the optimized diSPIM delivers more precise analysis of 3D cancer microarchitecture in human prostate biopsy than simpler light sheet microscopy arrangements.

  6. Optical design of an athermalised dual field of view step zoom optical system in MWIR

    NASA Astrophysics Data System (ADS)

    Kucukcelebi, Doruk

    2017-08-01

    In this paper, the optical design of an athermalised dual field of view step zoom optical system in MWIR (3.7μm - 4.8μm) is described. The dual field of view infrared optical system is designed based on the principle of passive athermalization method not only to achieve athermal optical system but also to keep the high image quality within the working temperature between -40°C and +60°C. The infrared optical system used in this study had a 320 pixel x 256 pixel resolution, 20μm pixel pitch size cooled MWIR focal plane array detector. In this study, the step zoom mechanism, which has the axial motion due to consisting of a lens group, is considered to simplify mechanical structure. The optical design was based on moving a single lens along the optical axis for changing the optical system's field of view not only to reduce the number of moving parts but also to athermalize for the optical system. The optical design began with an optimization process using paraxial optics when first-order optics parameters are determined. During the optimization process, in order to reduce aberrations, such as coma, astigmatism, spherical and chromatic aberrations, aspherical surfaces were used. As a result, athermalised dual field of view step zoom optical design is proposed and the performance of the design using proposed method was verified by providing the focus shifts, spot diagrams and MTF analyzes' plots.

  7. Environmental influences on energy balance-related behaviors: A dual-process view

    PubMed Central

    Kremers, Stef PJ; de Bruijn, Gert-Jan; Visscher, Tommy LS; van Mechelen, Willem; de Vries, Nanne K; Brug, Johannes

    2006-01-01

    Background Studies on the impact of the 'obesogenic' environment have often used non-theoretical approaches. In this journal's debate and in other papers authors have argued the necessity of formulating conceptual models for differentiating the causal role of environmental influences on behavior. Discussion The present paper aims to contribute to the debate by presenting a dual-process view on the environment – behavior relationship. This view is conceptualized in the EnRG framework (Environmental Research framework for weight Gain prevention). In the framework, behavior is postulated to be the result of a simultaneous influence of conscious and unconscious processes. Environmental influences are hypothesized to influence behavior both indirectly and directly. The indirect causal mechanism reflects the mediating role of behavior-specific cognitions in the influence of the environment on behavior. A direct influence reflects the automatic, unconscious, influence of the environment on behavior. Specific personal and behavioral factors are postulated to moderate the causal path (i.e., inducing either the automatic or the cognitively mediated environment – behavior relation). In addition, the EnRG framework applies an energy balance-approach, stimulating the integrated study of determinants of diet and physical activity. Conclusion The application of a dual-process view may guide research towards causal mechanisms linking specific environmental features with energy balance-related behaviors in distinct populations. The present paper is hoped to contribute to the evolution of a paradigm that may help to disentangle the role of 'obesogenic' environmental factors. PMID:16700907

  8. Indirect estimation of absorption properties for fine aerosol particles using AATSR observations: a case study of wildfires in Russia in 2010

    NASA Astrophysics Data System (ADS)

    Rodriguez, E.; Kolmonen, P.; Virtanen, T. H.; Sogacheva, L.; Sundstrom, A.-M.; de Leeuw, G.

    2015-08-01

    The Advanced Along-Track Scanning Radiometer (AATSR) on board the ENVISAT satellite is used to study aerosol properties. The retrieval of aerosol properties from satellite data is based on the optimized fit of simulated and measured reflectances at the top of the atmosphere (TOA). The simulations are made using a radiative transfer model with a variety of representative aerosol properties. The retrieval process utilizes a combination of four aerosol components, each of which is defined by their (lognormal) size distribution and a complex refractive index: a weakly and a strongly absorbing fine-mode component, coarse mode sea salt aerosol and coarse mode desert dust aerosol). These components are externally mixed to provide the aerosol model which in turn is used to calculate the aerosol optical depth (AOD). In the AATSR aerosol retrieval algorithm, the mixing of these components is decided by minimizing the error function given by the sum of the differences between measured and calculated path radiances at 3-4 wavelengths, where the path radiances are varied by varying the aerosol component mixing ratios. The continuous variation of the fine-mode components allows for the continuous variation of the fine-mode aerosol absorption. Assuming that the correct aerosol model (i.e. the correct mixing fractions of the four components) is selected during the retrieval process, also other aerosol properties could be computed such as the single scattering albedo (SSA). Implications of this assumption regarding the ratio of the weakly/strongly absorbing fine-mode fraction are investigated in this paper by evaluating the validity of the SSA thus obtained. The SSA is indirectly estimated for aerosol plumes with moderate-to-high AOD resulting from wildfires in Russia in the summer of 2010. Together with the AOD, the SSA provides the aerosol absorbing optical depth (AAOD). The results are compared with AERONET data, i.e. AOD level 2.0 and SSA and AAOD inversion products. The RMSE

  9. 40. View of dual projector system located in MWOC facility ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    40. View of dual projector system located in MWOC facility in transmitter building no. 102 by Bessler Company. System used to project images in MWOC on backlit screen system with fiber optic electro/mechanical system linked to computer output to indicate information on screen linked with display from projector system. - Clear Air Force Station, Ballistic Missile Early Warning System Site II, One mile west of mile marker 293.5 on Parks Highway, 5 miles southwest of Anderson, Anderson, Denali Borough, AK

  10. Synergy of stereo cloud top height and ORAC optimal estimation cloud retrieval: evaluation and application to AATSR

    NASA Astrophysics Data System (ADS)

    Fisher, Daniel; Poulsen, Caroline A.; Thomas, Gareth E.; Muller, Jan-Peter

    2016-03-01

    In this paper we evaluate the impact on the cloud parameter retrievals of the ORAC (Optimal Retrieval of Aerosol and Cloud) algorithm following the inclusion of stereo-derived cloud top heights as a priori information. This is performed in a mathematically rigorous way using the ORAC optimal estimation retrieval framework, which includes the facility to use such independent a priori information. Key to the use of a priori information is a characterisation of their associated uncertainty. This paper demonstrates the improvements that are possible using this approach and also considers their impact on the microphysical cloud parameters retrieved. The Along-Track Scanning Radiometer (AATSR) instrument has two views and three thermal channels, so it is well placed to demonstrate the synergy of the two techniques. The stereo retrieval is able to improve the accuracy of the retrieved cloud top height when compared to collocated Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO), particularly in the presence of boundary layer inversions and high clouds. The impact of the stereo a priori information on the microphysical cloud properties of cloud optical thickness (COT) and effective radius (RE) was evaluated and generally found to be very small for single-layer clouds conditions over open water (mean RE differences of 2.2 (±5.9) microns and mean COD differences of 0.5 (±1.8) for single-layer ice clouds over open water at elevations of above 9 km, which are most strongly affected by the inclusion of the a priori).

  11. Plume Detection and Plume Top Height Estimation using SLSTR

    NASA Astrophysics Data System (ADS)

    Virtanen, Timo H.; Kolmonen, Pekka; Sogacheva, Larisa; Rodriguez, Edith; Saponaro, Giulia; de Leeuw, Gerrit

    2017-04-01

    We present preliminary results on ash and desert dust plume detection and plume top height estimates based on satellite data from the Sea and Land Surface Temperature Radiometer (SLSTR) aboard Sentinel-3, launched in 2016. The methods are based on the previously developed AATSR Correlation Method (ACM) height estimation algorithm, which utilized the data of the preceding similar instrument, Advanced Along Track Scanning Radiometer (AATSR). The height estimate is based on the stereo-viewing capability of SLSTR, which allows to determine the parallax between the satellite's 55° backward and nadir views, and thus the corresponding height. The ash plume detection is based on the brightness temperature difference between between thermal infrared (TIR) channels centered at 11 and 12 μm, which show characteristic signals for both desert dust and ash plumes. The SLSTR instrument provides a unique combination of dual-view capability and a wavelength range from visible to thermal infrared, rendering it an ideal instrument for this work. Accurate information on the volcanic ash position is important for air traffic safety. The ACM algorithm can provide valuable data of both horizontal and vertical ash dispersion. These data may be useful for comparisons with other volcanic ash and desert dust retrieval methods and dispersion models. The current work is being carried out as part of the H2020 project EUNADICS-AV ("European Natural Disaster Coordination and Information System for Aviation"), which started in October 2016.

  12. An Exploration of Elementary Teachers' Views of Informal Reading Inventories in Dual Language Bilingual Programs

    ERIC Educational Resources Information Center

    Ascenzi-Moreno, Laura

    2016-01-01

    This study examines how elementary teachers (grades three through five) in dual-language, bilingual programs (Spanish/English) view informal reading inventories (IRIs) to support their students' reading growth. The research, conducted in an urban district in the Northeastern United States, draws on interviews with 20 teachers in these programs.…

  13. Dual-view integral imaging three-dimensional display using polarized glasses.

    PubMed

    Wu, Fei; Lv, Guo-Jiao; Deng, Huan; Zhao, Bai-Chuan; Wang, Qiong-Hua

    2018-02-20

    We propose a dual-view integral imaging (DVII) three-dimensional (3D) display using polarized glasses. The DVII 3D display consists of a display panel, a polarized parallax barrier, a microlens array, and two pairs of polarized glasses. Two kinds of elemental images, which are captured from two different 3D scenes, are alternately arranged on the display panel. The polarized parallax barrier is attached to the display panel and composed of two kinds of units that are also alternately arranged. The polarization directions between adjacent units are perpendicular. The polarization directions of the two pairs of polarized glasses are the same as those of the two kinds of units of the polarized parallax barrier, respectively. The lights emitted from the two kinds of elemental images are modulated by the corresponding polarizer units and microlenses, respectively. Two different 3D images are reconstructed in the viewing zone and separated by using two pairs of polarized glasses. A prototype of the DVII 3D display is developed and two 3D images can be presented simultaneously, verifying the hypothesis.

  14. Analysis of Rosetta/VIRTIS spectra of earth using observations from ENVISAT/AATSR, TERRA/MODIS and ENVISAT/SCIAMACHY, and radiative-transfer simulations

    NASA Astrophysics Data System (ADS)

    Hurley, J.; Irwin, P. G. J.; Adriani, A.; Moriconi, M.; Oliva, F.; Capaccioni, F.; Smith, A.; Filacchione, G.; Tosi, F.; Thomas, G.

    2014-01-01

    Rosetta, the Solar System cornerstone mission of ESA's Horizon 2000 programme, consists of an orbiter and a lander, and is due to arrive at the comet 67P/Churyumov-Gerasimenko in May 2014. Following its 2004 launch, Rosetta carried out a series of planetary fly-bys and gravitational assists. On these close fly-bys of the Earth, measurements were taken by the Visible Infrared Thermal Imaging Spectrometer (VIRTIS). Analysis of these spectra and comparison with spectra acquired by Earth-observing satellites can support the verification of the inflight calibration of Rosetta/VIRTIS. In this paper, measurements taken by VIRTIS in November 2009 are compared with suitable coincident data from Earth-observing instruments (ESA-ENVISAT/AATSR and SCIAMACHY, and EOS-TERRA/MODIS). Radiative transfer simulations using NEMESIS (Irwin et al., 2008) are fit to the fly-by data taken by VIRTIS, using representative atmospheric and surface parameters. VIRTIS measurements correlate 90% with AATSR's, 85-94% with MODIS, and 82-88% with SCIAMACHYs. The VIRTIS spectra are reproducible in the 1-5 μm region, except in the 1.4 μm deep water vapour spectral absorption band in the near-infrared in cases in which the radiance is very low (cloud-free topographies), where VIRTIS consistently registers more radiance than do MODIS and SCIAMACHY. Over these cloud-free regions, VIRTIS registers radiances a factor of 3-10 larger than SCIAMACHY and of 3-8 greater than MODIS. It is speculated that this discrepancy could be due to a spectral light leak originating from reflections from the order-sorting filters above the detector around 1.4 μm.

  15. Contrails and Climate Change: An Investigation of the Role of Aviation-Induced-Cloudiness on the Ireland Climate Using AATSR Imagery

    NASA Astrophysics Data System (ADS)

    Whelan, Gillian M.; Cawkwell, Fiona; Mannstein, Hermann; Minnis, Patrick

    2010-12-01

    Contrails, or 'condensation trails', produced in the wake of jet aircraft have been found to have a small but significant global net climate-warming effect [1]. When atmospheric conditions are favorable (i.e. when ambient atmospheric humidity is high and temperature is below a threshold value of typically less than -40oC), contrails can persist for several hours, grow to become several kilometers long and can also trigger additional cirrus- cloud formation as they spread - which can further impact climate! Due to Ireland's proximity to the North Atlantic Flight Corridor, large volumes of high-altitude overflights cross Ireland daily. Contrails are essentially artificial-linear-ice-clouds at a lower temperature than the surrounding atmosphere and so are visible in 1 Km satellite imagery at the 11 and 12 μm wavelengths; but are better detected in the temperature difference image between these two thermal channels. An automated Contrail Detection Algorithm (CDA) is applied to AATSR thermal imagery over Ireland, and the percentage contrail-coverage of each scene determined. Preliminary results, based on 2008 morning and evening AATSR overpasses show a similar annual average contrail-coverage when present of 0.25% and 0.19% respectively, even though air-traffic density is typically several times higher during the morning overpasses. Cases of excessive contrail-coverage, of up to 2.06% have been observed in combination with extensive cirrus-coverage over Ireland. Results from meteorological data indicate more highly favorable atmospheric conditions for contrail formation and persistence in 00h00 and 06h00 radiosonde ascents; which corresponds to a night-time peak in high-altitude flights over Ireland. Furthermore, exceptionally thick contrail-susceptible-atmospheric layers are found in conjunction with cases of excessive satellite-derived- contrail-coverage.

  16. Dual Career Families.

    ERIC Educational Resources Information Center

    Farmer, Helen S.

    Home-career conflict may exist in varying degrees for both spouses in a dual-career couple. Home-career conflict exists when a dual-career wife values both homemaking and career and views some aspects of these two roles as incompatible. Home-career conflict results when a dual-career husband values his own career and that of his wife, but is…

  17. Examining the Affordances of Dual Cognitive Processing to Explain the Development of High School Students' Nature of Science Views

    NASA Astrophysics Data System (ADS)

    Jackson, Luke M.

    This mixed method study was aimed at examining the influence of dual processing (Type 1 and Type 2 thinking) on the development of high school students' nature of science (NOS) views. Type 1 thinking is intuitive, experiential, and heuristic. Type 2 thinking is rational, analytical, and explicit. Three research questions were asked: (1) Do the experiential process (Type 1) and the logical process (Type 2) influence the development of students' NOS views? (2) If there is an influence on students' NOS views, then what is the nature of relationship between the experiential process (Type 1) and the development of NOS views? (3) What is the nature of relationship between the logical process (Type 2) and the development of NOS views? The Views of Nature of Science Questionnaire C (VNOS-C; Lederman, Abd-El-Khalick, Bell, & Schwartz, 2002) was administered to 29 high school students at the beginning and at the end of an explicit-reflective NOS intervention offered in an Advanced Placement environmental science course. Changes in students' NOS views were calculated through a chi-square test and examining the percentage of students holding NOS views at various levels of sophistication. With the chi-square goodness of fit test performed, the relationship between pre and post NOS scores was not significant, X2(3, 29) = 4.78, p <.05. The informed and preinformed NOS views increased (14%, 17%) in frequency while the mixed and uninformed NOS views decreased (i.e. improved 26%, 24%) in frequency from pre to posttest. The reading discussions were coded based on the EBR framework (Furtak et al., 2010) to analyze the use of dual processing. Type1 and Type 2 thinking were both used during the intervention and reading reflections. Type 2 thinking was more prominent when analyzing a problem, formulating a hypothesis, or stating logical claims. The association of NOS education and Type 1 and Type 2 thinking in scientific literacy was examined, and implications and future research are

  18. Limited Angle Dual Modality Breast Imaging

    NASA Astrophysics Data System (ADS)

    More, Mitali J.; Li, Heng; Goodale, Patricia J.; Zheng, Yibin; Majewski, Stan; Popov, Vladimir; Welch, Benjamin; Williams, Mark B.

    2007-06-01

    We are developing a dual modality breast scanner that can obtain x-ray transmission and gamma ray emission images in succession at multiple viewing angles with the breast held under mild compression. These views are reconstructed and fused to obtain three-dimensional images that combine structural and functional information. Here, we describe the dual modality system and present results of phantom experiments designed to test the system's ability to obtain fused volumetric dual modality data sets from a limited number of projections, acquired over a limited (less than 180 degrees) angular range. We also present initial results from phantom experiments conducted to optimize the acquisition geometry for gamma imaging. The optimization parameters include the total number of views and the angular range over which these views should be spread, while keeping the total number of detected counts fixed. We have found that in general, for a fixed number of views centered around the direction perpendicular to the direction of compression, in-plane contrast and SNR are improved as the angular range of the views is decreased. The improvement in contrast and SNR with decreasing angular range is much greater for deeper lesions and for a smaller number of views. However, the z-resolution of the lesion is significantly reduced with decreasing angular range. Finally, we present results from limited angle tomography scans using a system with dual, opposing heads.

  19. Dual view Geostationary Earth Radiation Budget from the Meteosat Second Generation satellites.

    NASA Astrophysics Data System (ADS)

    Dewitte, Steven; Clerbaux, Nicolas; Ipe, Alessandro; Baudrez, Edward; Moreels, Johan

    2017-04-01

    The diurnal cycle of the radiation budget is a key component of the tropical climate. The geostationary Meteosat Second Generation (MSG) satellites carrying both the broadband Geostationary Earth Radiation Budget (GERB) instrument with nadir resolution of 50 km and the multispectral Spinning Enhanced VIsible and InfraRed Imager (SEVIRI) with nadir resolution of 3 km offer a unique opportunity to observe this diurnal cycle. The geostationary orbit has the advantage of good temporal sampling but the disadvantage of fixed viewing angles, which makes the measurements of the broadband Top Of Atmosphere (TOA) radiative fluxes more sensitive to angular dependent errors. The Meteosat-10 (MSG-3) satellite observes the earth from the standard position at 0° longitude. From October 2016 onwards the Meteosat-8 (MSG-1) satellite makes observations from a new position at 41.5° East over the Indian Ocean. The dual view from Meteosat-8 and Meteosat-10 allows the assessment and correction of angular dependent systematic errors of the flux estimates. We demonstrate this capability with the validation of a new method for the estimation of the clear-sky TOA albedo from the SEVIRI instruments.

  20. Dual-view plane illumination microscopy for rapid and spatially isotropic imaging

    PubMed Central

    Kumar, Abhishek; Wu, Yicong; Christensen, Ryan; Chandris, Panagiotis; Gandler, William; McCreedy, Evan; Bokinsky, Alexandra; Colón-Ramos, Daniel A; Bao, Zhirong; McAuliffe, Matthew; Rondeau, Gary; Shroff, Hari

    2015-01-01

    We describe the construction and use of a compact dual-view inverted selective plane illumination microscope (diSPIM) for time-lapse volumetric (4D) imaging of living samples at subcellular resolution. Our protocol enables a biologist with some prior microscopy experience to assemble a diSPIM from commercially available parts, to align optics and test system performance, to prepare samples, and to control hardware and data processing with our software. Unlike existing light sheet microscopy protocols, our method does not require the sample to be embedded in agarose; instead, samples are prepared conventionally on glass coverslips. Tissue culture cells and Caenorhabditis elegans embryos are used as examples in this protocol; successful implementation of the protocol results in isotropic resolution and acquisition speeds up to several volumes per s on these samples. Assembling and verifying diSPIM performance takes ~6 d, sample preparation and data acquisition take up to 5 d and postprocessing takes 3–8 h, depending on the size of the data. PMID:25299154

  1. Examining the Affordances of Dual Cognitive Processing to Explain the Development of High School Students' Nature of Science Views

    ERIC Educational Resources Information Center

    Jackson, Luke M.

    2017-01-01

    This mixed method study was aimed at examining the influence of dual processing (Type 1 and Type 2 thinking) on the development of high school students' nature of science (NOS) views. Type 1 thinking is intuitive, experiential, and heuristic. Type 2 thinking is rational, analytical, and explicit. Three research questions were asked: (1) Do the…

  2. Dual Coding and Bilingual Memory.

    ERIC Educational Resources Information Center

    Paivio, Allan; Lambert, Wallace

    1981-01-01

    Describes study which tested a dual coding approach to bilingual memory using tasks that permit comparison of the effects of bilingual encoding with verbal-nonverbal dual encoding items. Results provide strong support for a version of the independent or separate stories view of bilingual memory. (Author/BK)

  3. The validation and analysis of novel stereo-derived smoke plume products from AATSR and their application to fire events from the 2008 Russian fire season

    NASA Astrophysics Data System (ADS)

    Fisher, D.; Muller, J.-P.; Yershov, V.

    2012-04-01

    Biomass burning events in Boreal forests generate significant amounts of important greenhouse gases; including CO2, CO, NOx [1,2]. When the injection height is above the boundary layer (BL), the lifespan of these chemicals is greatly extended, as is their spatial distribution [2]. Typically, in chemical transport models (CTMs), BL injection heights are simplified and assumed to be constant. This is in part due to poor data availability. This leads to a reduction in the accuracy of the distribution outputs from such models. To generate better smoke-plume injection height (SPIH) inputs into CTMs, measurements need to be made of smoke plume heights, which can be used as a proxy for aerosol injection height into the atmosphere. One method of measuring SPIH is through stereo-photogrammetry [5], originally applied to optically thick clouds [3,4]. Here, we present validation and analysis of the M6 stereo matching method [5] for the determination of SPIHs applied to AATSR. It is referred to as M6 due to a shared heritage with the other M-series matchers [3,4]. M6 utilizes novel normalization and matching techniques to generate improved results, in terms of coverage and accuracy, over these afore-referenced matchers of similar type. Validation is carried out against independent, coincident and higher resolution SPIH measurements obtained from both the CALIOP instrument carried onboard the NASA-CNES CALIPSO satellite and also against measurements from the MISR Smoke Plume Product obtained by manual measurements using the MINX system (http://www.openchannelsoftware.com/projects/MINX) with the MISR instrument onboard the NASA satellite Terra. The results of this inter-comparison show an excellent agreement between AATSR and the CALIOP and MISR measurements. Further an inter-comparison between a heritage M-series matcher, M4 [3], also against MISR data demonstrates the significant improvement in SPIH generated by M6. [1] Crutzen, P. J., L. E. Heidt, et al. (1979). "Biomass

  4. A Dual Coding View of Vocabulary Learning

    ERIC Educational Resources Information Center

    Sadoski, Mark

    2005-01-01

    A theoretical perspective on acquiring sight vocabulary and developing meaningful vocabulary is presented. Dual Coding Theory assumes that cognition occurs in two independent but connected codes: a verbal code for language and a nonverbal code for mental imagery. The mixed research literature on using pictures in teaching sight vocabulary is…

  5. The Improved Dual-view Field Goniometer System FIGOS

    PubMed Central

    Schopfer, Jürg; Dangel, Stefan; Kneubühler, Mathias; Itten, Klaus I.

    2008-01-01

    In spectrodirectional Remote Sensing (RS) the Earth's surface reflectance characteristics are studied by means of their angular dimensions. Almost all natural surfaces exhibit an individual anisotropic reflectance behaviour due to the contrast between the optical properties of surface elements and background and the geometric surface properties of the observed scene. The underlying concept, which describes the reflectance characteristic of a specific surface area, is called the bidirectional reflectance distribution function (BRDF). BRDF knowledge is essential for both correction of directional effects in RS data and quantitative retrieval of surface parameters. Ground-based spectrodirectional measurements are usually performed with goniometer systems. An accurate retrieval of the bidirectional reflectance factors (BRF) from field goniometer measurements requires hyperspectral knowledge of the angular distribution of the reflected and the incident radiation. However, prior to the study at hand, no operational goniometer system was able to fulfill this requirement. This study presents the first dual-view field goniometer system, which is able to simultaneously collect both the reflected and the incident radiation at high angular and spectral resolution and, thus, providing the necessary spectrodirectional datasets to accurately retrieve the surface specific BRF. Furthermore, the angular distribution of the incoming diffuse radiation is characterized for various atmospheric conditions and the BRF retrieval is performed for an artificial target and compared to laboratory spectrodirectional measurement results obtained with the same goniometer system. Suggestions for further improving goniometer systems are given and the need for intercalibration of various goniometers as well as for standardizing spectrodirectional measurements is expressed. PMID:27873805

  6. The Improved Dual-view Field Goniometer System FIGOS.

    PubMed

    Schopfer, Jürg; Dangel, Stefan; Kneubühler, Mathias; Itten, Klaus I

    2008-08-28

    In spectrodirectional Remote Sensing (RS) the Earth's surface reflectance characteristics are studied by means of their angular dimensions. Almost all natural surfaces exhibit an individual anisotropic reflectance behaviour due to the contrast between the optical properties of surface elements and background and the geometric surface properties of the observed scene. The underlying concept, which describes the reflectance characteristic of a specific surface area, is called the bidirectional reflectance distribution function (BRDF). BRDF knowledge is essential for both correction of directional effects in RS data and quantitative retrieval of surface parameters. Ground-based spectrodirectional measurements are usually performed with goniometer systems. An accurate retrieval of the bidirectional reflectance factors (BRF) from field goniometer measurements requires hyperspectral knowledge of the angular distribution of the reflected and the incident radiation. However, prior to the study at hand, no operational goniometer system was able to fulfill this requirement. This study presents the first dual-view field goniometer system, which is able to simultaneously collect both the reflected and the incident radiation at high angular and spectral resolution and, thus, providing the necessary spectrodirectional datasets to accurately retrieve the surface specific BRF. Furthermore, the angular distribution of the incoming diffuse radiation is characterized for various atmospheric conditions and the BRF retrieval is performed for an artificial target and compared to laboratory spectrodirectional measurement results obtained with the same goniometer system. Suggestions for further improving goniometer systems are given and the need for intercalibration of various goniometers as well as for standardizing spectrodirectional measurements is expressed.

  7. A Time Series of Mean Global Sea Surface Temperature from the Along-Track Scanning Radiometers

    NASA Astrophysics Data System (ADS)

    Veal, Karen L.; Corlett, Gary; Remedios, John; Llewellyn-Jones, David

    2010-12-01

    A climate data set requires a long time series of consistently processed data with suitably long periods of overlap of different instruments which allows characterization of any inter-instrument biases. The data obtained from ESA's three Along-Track Scanning Radiometers (ATSRs) together comprise an 18 year record of SST with overlap periods of at least 6 months. The data from all three ATSRs has been consistently processed. These factors together with the stability of the instruments and the precision of the derived SST makes this data set eminently suitable for the construction of a time series of SST that complies with many of the GCOS requirements for a climate data set. A time series of global and regional average SST anomalies has been constructed from the ATSR version 2 data set. An analysis of the overlap periods of successive instruments was used to remove intra-series biases and align the series to a common reference. An ATSR climatology has been developed and has been used to calculate the SST anomalies. The ATSR-1 time series and the AATSR time series have been aligned to ATSR-2. The largest adjustment is ~0.2 K between ATSR-2 and AATSR which is suspected to be due to a shift of the 12 μm filter function for AATSR. An uncertainty of 0.06 K is assigned to the relative anomaly record that is derived from the dual three-channel night-time data. A relative uncertainty of 0.07 K is assigned to the dual night-time two-channel record, except in the ATSR-1 period (1994-1996) where it is larger.

  8. Dual Active Bridge based DC Transformer LabVIEW FPGA Control Code

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    In the area of power electronics control, Field Programmable Gate Arrays (FPGAs) have the capability to outperform their Digital Signal Processor (DSP) counterparts due to the FPGA’s ability to implement true parallel processing and therefore facilitate higher switching frequencies, higher control bandwidth, and/or enhanced functionality. National Instruments (NI) has developed two platforms, Compact RIO (cRIO) and Single Board RIO (sbRIO), which combine a real-time processor with an FPGA. The FPGA can be programmed with a subset of the well-known LabVIEW graphical programming language. The candidate software implements complete control algorithms in LabVIEW FPGA for a DC Transformer (DCX) based onmore » a dual active bridge (DAB). A DCX is an isolated bi-directional DC-DC converter designed to operate at unity conversion ratio, M, defined by where Vin is the primary-side DC bus voltage, Vout is the secondary-side DC bus voltage, and n is the turns ratio of the embedded high frequency transformer (HFX). The DCX based on a DAB incorporates two H-bridges, a resonant inductor, and an HFX to provide this functionality. The candidate software employs phase-shift modulation of the two H-bridges and a feedback loop to regulate the conversion ratio at unity. The software also includes alarm-handling capabilities as well as debugging and tuning tools. The software fits on the Xilinx Virtex V LX110 FPGA embedded in the NI cRIO-9118 FPGA chassis, and with a 40 MHz base clock, supports a modulation update rate of 40 MHz, and user-settable switching frequencies and synchronized control loop update rates of tens of kHz.« less

  9. Enhancement of Dual-Band Reflection-Mode Circular Polarizers Using Dual-Layer Rectangular Frequency Selective Surfaces

    NASA Astrophysics Data System (ADS)

    Fartookzadeh, M.; Mohseni Armaki, S. H.

    2016-10-01

    A new kind of dual-band reflection-mode circular polarizers (RMCPs) is introduced with wide bandwidth and wide-view at the operating frequencies. The proposed RMCPs are based on dual-layer rectangular patches on both sides of a substrate, separated by a foam or air layer from the ground plane. Required TE susceptance of the first layer patches to produce circular polarization is calculated using the equivalent transmission line model. Dimensions of the RMCP are obtained using parametrical study for the two frequency bands, 1.9-2.3 GHz and 7.9-8.3 GHz. In addition, it is indicated that the accepted view angle and bandwidth of the proposed dual-layer RMCP are improved compared with the single layer RMCP, significantly. Moreover, a tradeoff is observed for the dual-layer RMCP on the bandwidths of X band and S band that can be controlled by propagation angle of the incident wave. The proposed RMCP has 30.5 % and 33.7 % bandwidths for less than 3 dB axial ratio with incident angles {\\theta}max=50{\\deg} and {\\theta}min=35{\\deg}. Finally, simulation results are met by the measurement for three angles of the incident wave.

  10. What Makes Dual-Career Marriages Tick?

    ERIC Educational Resources Information Center

    Gilbert, Lucia Albino

    A dual-career family is a family in which both spouses are committed to occupational work and to a family life together and support each other's desires to combine roles that traditionally were viewed as incompatible. Male socialization in the areas of entitlement, dependency, and nurturance can cause problems for men in dual-career marriages. In…

  11. The double crush syndrome revisited--a Delphi study to reveal current expert views on mechanisms underlying dual nerve disorders.

    PubMed

    Schmid, Annina B; Coppieters, Michel W

    2011-12-01

    A high prevalence of dual nerve disorders is frequently reported. How a secondary nerve disorder may develop following a primary nerve disorder remains largely unknown. Although still frequently cited, most explanatory theories were formulated many years ago. Considering recent advances in neuroscience, it is uncertain whether these theories still reflect current expert opinion. A Delphi study was conducted to update views on potential mechanisms underlying dual nerve disorders. In three rounds, seventeen international experts in the field of peripheral nerve disorders were asked to list possible mechanisms and rate their plausibility. Mechanisms with a median plausibility rating of ≥7 out of 10 were considered highly plausible. The experts identified fourteen mechanisms associated with a first nerve disorder that may predispose to the development of another nerve disorder. Of these fourteen mechanisms, nine have not previously been linked to double crush. Four mechanisms were considered highly plausible (impaired axonal transport, ion channel up or downregulation, inflammation in the dorsal root ganglia and neuroma-in-continuity). Eight additional mechanisms were listed which are not triggered by a primary nerve disorder, but may render the nervous system more vulnerable to multiple nerve disorders, such as systemic diseases and neurotoxic medication. Even though many mechanisms were classified as plausible or highly plausible, overall plausibility ratings varied widely. Experts indicated that a wide range of mechanisms has to be considered to better understand dual nerve disorders. Previously listed theories cannot be discarded, but may be insufficient to explain the high prevalence of dual nerve disorders. Copyright © 2011 Elsevier Ltd. All rights reserved.

  12. Dual source and dual detector arrays tetrahedron beam computed tomography for image guided radiotherapy

    NASA Astrophysics Data System (ADS)

    Kim, Joshua; Lu, Weiguo; Zhang, Tiezhi

    2014-02-01

    Cone-beam computed tomography (CBCT) is an important online imaging modality for image guided radiotherapy. But suboptimal image quality and the lack of a real-time stereoscopic imaging function limit its implementation in advanced treatment techniques, such as online adaptive and 4D radiotherapy. Tetrahedron beam computed tomography (TBCT) is a novel online imaging modality designed to improve on the image quality provided by CBCT. TBCT geometry is flexible, and multiple detector and source arrays can be used for different applications. In this paper, we describe a novel dual source-dual detector TBCT system that is specially designed for LINAC radiation treatment machines. The imaging system is positioned in-line with the MV beam and is composed of two linear array x-ray sources mounted aside the electrical portal imaging device and two linear arrays of x-ray detectors mounted below the machine head. The detector and x-ray source arrays are orthogonal to each other, and each pair of source and detector arrays forms a tetrahedral volume. Four planer images can be obtained from different view angles at each gantry position at a frame rate as high as 20 frames per second. The overlapped regions provide a stereoscopic field of view of approximately 10-15 cm. With a half gantry rotation, a volumetric CT image can be reconstructed having a 45 cm field of view. Due to the scatter rejecting design of the TBCT geometry, the system can potentially produce high quality 2D and 3D images with less radiation exposure. The design of the dual source-dual detector system is described, and preliminary results of studies performed on numerical phantoms and simulated patient data are presented.

  13. Dual-induced multifractality in online viewing activity.

    PubMed

    Qin, Yu-Hao; Zhao, Zhi-Dan; Cai, Shi-Min; Gao, Liang; Stanley, H Eugene

    2018-01-01

    Although recent studies have found that the long-term correlations relating to the fat-tailed distribution of inter-event times exist in human activity and that these correlations indicate the presence of fractality, the property of fractality and its origin have not been analyzed. We use both detrended fluctuation analysis and multifractal detrended fluctuation analysis to analyze the time series in online viewing activity separating from Movielens and Netflix. We find long-term correlations at both the individual and communal levels and that the extent of correlation at the individual level is determined by the activity level. These long-term correlations also indicate that there is fractality in the pattern of online viewing. We first find a multifractality that results from the combined effect of the fat-tailed distribution of inter-event times (i.e., the times between successive viewing actions of individuals) and the long-term correlations in online viewing activity and verify this finding using three synthesized series. Therefore, it can be concluded that the multifractality in online viewing activity is caused by both the fat-tailed distribution of inter-event times and the long-term correlations and that this enlarges the generic property of human activity to include not just physical space but also cyberspace.

  14. Dual-induced multifractality in online viewing activity

    NASA Astrophysics Data System (ADS)

    Qin, Yu-Hao; Zhao, Zhi-Dan; Cai, Shi-Min; Gao, Liang; Stanley, H. Eugene

    2018-01-01

    Although recent studies have found that the long-term correlations relating to the fat-tailed distribution of inter-event times exist in human activity and that these correlations indicate the presence of fractality, the property of fractality and its origin have not been analyzed. We use both detrended fluctuation analysis and multifractal detrended fluctuation analysis to analyze the time series in online viewing activity separating from Movielens and Netflix. We find long-term correlations at both the individual and communal levels and that the extent of correlation at the individual level is determined by the activity level. These long-term correlations also indicate that there is fractality in the pattern of online viewing. We first find a multifractality that results from the combined effect of the fat-tailed distribution of inter-event times (i.e., the times between successive viewing actions of individuals) and the long-term correlations in online viewing activity and verify this finding using three synthesized series. Therefore, it can be concluded that the multifractality in online viewing activity is caused by both the fat-tailed distribution of inter-event times and the long-term correlations and that this enlarges the generic property of human activity to include not just physical space but also cyberspace.

  15. Single-source dual-energy spectral multidetector CT of pancreatic adenocarcinoma: optimization of energy level viewing significantly increases lesion contrast.

    PubMed

    Patel, B N; Thomas, J V; Lockhart, M E; Berland, L L; Morgan, D E

    2013-02-01

    To evaluate lesion contrast in pancreatic adenocarcinoma patients using spectral multidetector computed tomography (MDCT) analysis. The present institutional review board-approved, Health Insurance Portability and Accountability Act of 1996 (HIPAA)-compliant retrospective study evaluated 64 consecutive adults with pancreatic adenocarcinoma examined using a standardized, multiphasic protocol on a single-source, dual-energy MDCT system. Pancreatic phase images (35 s) were acquired in dual-energy mode; unenhanced and portal venous phases used standard MDCT. Lesion contrast was evaluated on an independent workstation using dual-energy analysis software, comparing tumour to non-tumoural pancreas attenuation (HU) differences and tumour diameter at three energy levels: 70 keV; individual subject-optimized viewing energy level (based on the maximum contrast-to-noise ratio, CNR); and 45 keV. The image noise was measured for the same three energies. Differences in lesion contrast, diameter, and noise between the different energy levels were analysed using analysis of variance (ANOVA). Quantitative differences in contrast gain between 70 keV and CNR-optimized viewing energies, and between CNR-optimized and 45 keV were compared using the paired t-test. Thirty-four women and 30 men (mean age 68 years) had a mean tumour diameter of 3.6 cm. The median optimized energy level was 50 keV (range 40-77). The mean ± SD lesion contrast values (non-tumoural pancreas - tumour attenuation) were: 57 ± 29, 115 ± 70, and 146 ± 74 HU (p = 0.0005); the lengths of the tumours were: 3.6, 3.3, and 3.1 cm, respectively (p = 0.026); and the contrast to noise ratios were: 24 ± 7, 39 ± 12, and 59 ± 17 (p = 0.0005) for 70 keV, the optimized energy level, and 45 keV, respectively. For individuals, the mean ± SD contrast gain from 70 keV to the optimized energy level was 59 ± 45 HU; and the mean ± SD contrast gain from the optimized energy level to 45 keV was 31 ± 25 HU (p = 0

  16. Two decades of satellite observations of AOD over mainland China using ATSR-2, AATSR and MODIS/Terra: data set evaluation and large-scale patterns

    NASA Astrophysics Data System (ADS)

    de Leeuw, Gerrit; Sogacheva, Larisa; Rodriguez, Edith; Kourtidis, Konstantinos; Georgoulias, Aristeidis K.; Alexandri, Georgia; Amiridis, Vassilis; Proestakis, Emmanouil; Marinou, Eleni; Xue, Yong; van der A, Ronald

    2018-02-01

    The retrieval of aerosol properties from satellite observations provides their spatial distribution over a wide area in cloud-free conditions. As such, they complement ground-based measurements by providing information over sparsely instrumented areas, albeit that significant differences may exist in both the type of information obtained and the temporal information from satellite and ground-based observations. In this paper, information from different types of satellite-based instruments is used to provide a 3-D climatology of aerosol properties over mainland China, i.e., vertical profiles of extinction coefficients from the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP), a lidar flying aboard the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) satellite and the column-integrated extinction (aerosol optical depth - AOD) available from three radiometers: the European Space Agency (ESA)'s Along-Track Scanning Radiometer version 2 (ATSR-2), Advanced Along-Track Scanning Radiometer (AATSR) (together referred to as ATSR) and NASA's Moderate Resolution Imaging Spectroradiometer (MODIS) aboard the Terra satellite, together spanning the period 1995-2015. AOD data are retrieved from ATSR using the ATSR dual view (ADV) v2.31 algorithm, while for MODIS Collection 6 (C6) the AOD data set is used that was obtained from merging the AODs obtained from the dark target (DT) and deep blue (DB) algorithms, further referred to as the DTDB merged AOD product. These data sets are validated and differences are compared using Aerosol Robotic Network (AERONET) version 2 L2.0 AOD data as reference. The results show that, over China, ATSR slightly underestimates the AOD and MODIS slightly overestimates the AOD. Consequently, ATSR AOD is overall lower than that from MODIS, and the difference increases with increasing AOD. The comparison also shows that neither of the ATSR and MODIS AOD data sets is better than the other one everywhere. However, ATSR ADV

  17. Dual source and dual detector arrays tetrahedron beam computed tomography for image guided radiotherapy.

    PubMed

    Kim, Joshua; Lu, Weiguo; Zhang, Tiezhi

    2014-02-07

    Cone-beam computed tomography (CBCT) is an important online imaging modality for image guided radiotherapy. But suboptimal image quality and the lack of a real-time stereoscopic imaging function limit its implementation in advanced treatment techniques, such as online adaptive and 4D radiotherapy. Tetrahedron beam computed tomography (TBCT) is a novel online imaging modality designed to improve on the image quality provided by CBCT. TBCT geometry is flexible, and multiple detector and source arrays can be used for different applications. In this paper, we describe a novel dual source-dual detector TBCT system that is specially designed for LINAC radiation treatment machines. The imaging system is positioned in-line with the MV beam and is composed of two linear array x-ray sources mounted aside the electrical portal imaging device and two linear arrays of x-ray detectors mounted below the machine head. The detector and x-ray source arrays are orthogonal to each other, and each pair of source and detector arrays forms a tetrahedral volume. Four planer images can be obtained from different view angles at each gantry position at a frame rate as high as 20 frames per second. The overlapped regions provide a stereoscopic field of view of approximately 10-15 cm. With a half gantry rotation, a volumetric CT image can be reconstructed having a 45 cm field of view. Due to the scatter rejecting design of the TBCT geometry, the system can potentially produce high quality 2D and 3D images with less radiation exposure. The design of the dual source-dual detector system is described, and preliminary results of studies performed on numerical phantoms and simulated patient data are presented.

  18. Single-beam, dual-view digital holographic interferometry for biomechanical strain measurements of biological objects

    NASA Astrophysics Data System (ADS)

    Pantelić, Dejan V.; Grujić, Dušan Ž.; Vasiljević, Darko M.

    2014-12-01

    We describe a method for dual-view biomechanical strain measurements of highly asymmetrical biological objects, like teeth or bones. By using a spherical mirror, we were able to simultaneously record a digital hologram of the object itself and the mirror image of its (otherwise invisible) rear side. A single laser beam was sufficient to illuminate both sides of the object, and to provide a reference beam. As a result, the system was mechanically very stable, enabling long exposure times (up to 2 min) without the need for vibration isolation. The setup is simple to construct and adjust, and can be used to interferometrically observe any object that is smaller than the mirror diameter. Parallel data processing on a CUDA-enabled (compute unified device architecture) graphics card was used to reconstruct digital holograms and to further correct image distortion. We used the setup to measure the deformation of a tooth due to mastication forces. The finite-element method was used to compare experimental results and theoretical predictions.

  19. Single-beam, dual-view digital holographic interferometry for biomechanical strain measurements of biological objects.

    PubMed

    Pantelić, Dejan V; Grujić, Dušan Ž; Vasiljević, Darko M

    2014-12-01

    We describe a method for dual-view biomechanical strain measurements of highly asymmetrical biological objects, like teeth or bones. By using a spherical mirror, we were able to simultaneously record a digital hologram of the object itself and the mirror image of its (otherwise invisible) rear side. A single laser beam was sufficient to illuminate both sides of the object, and to provide a reference beam. As a result, the system was mechanically very stable, enabling long exposure times (up to 2 min) without the need for vibration isolation. The setup is simple to construct and adjust, and can be used to interferometrically observe any object that is smaller than the mirror diameter. Parallel data processing on a CUDA-enabled (compute unified device architecture) graphics card was used to reconstruct digital holograms and to further correct image distortion. We used the setup to measure the deformation of a tooth due to mastication forces. The finite-element method was used to compare experimental results and theoretical predictions.

  20. Multi-Annual Data Products on Turbulent Heat Fluxes at the Local and Continental Scale Using AATSR and FY-2 Data

    NASA Astrophysics Data System (ADS)

    Menenti, M.; Ghafarian, H.; Tang, B.; Faivre, R.; Colin, J.; Jia, L.; Roupios, L.

    2013-01-01

    This paper summarizes the results of studies carried in the framework of the Dragon 2 Program - Project 5322 Key Eco-Hydrological Parameters Retrieval and Land Data Assimilation System Development in a Typical Inland River Basin of Chinas Arid Region. The investigations were focused on monitoring the fluxes of energy and water at the land-atmosphere interface across a range of spatial scales, using multi-spectral radiometric data collected by space-borne imaging radiometers. At the local scale a new approach to parameterize heat and vapour fluxes was developed and applied using Computational Fluid Dynamics to describe state and dynamics of the boundary layer over the heterogeneous and 3D structured land surface. An airborne scanning LIDAR was used to capture in detail surface geometry. Over the large area of the Qinghai-Tibet Plateau a land-atmospheric model was used to characterize the atmospheric Planetary Boundary Layer. The effect of land surface heterogeneity and structure on the exchange of heat and water was captured using the bi-angular observations of brightness temperature provided by the AATSR imaging radiometer. The heat and water flux densities were calculated hourly with Feng-Yun C, D and E VISSR data over the Qinghai-Tibet Plateau and the headwaters of main rivers around it.

  1. Performance of basic manipulation and intracorporeal suturing tasks in a robotic surgical system: single- versus dual-monitor views.

    PubMed

    Shah, Rachit D; Cao, Alex; Golenberg, Lavie; Ellis, R Darin; Auner, Gregory W; Pandya, Abhilash K; Klein, Michael D

    2009-04-01

    Technical advances in the application of laparoscopic and robotic surgical systems have improved platform usability. The authors hypothesized that using two monitors instead of one would lead to faster performance with fewer errors. All tasks were performed using a surgical robot in a training box. One of the monitors was a standard camera with two preset zoom levels (zoomed in and zoomed out, single-monitor condition). The second monitor provided a static panoramic view of the whole surgical field. The standard camera was static at the zoomed-in level for the dual-monitor condition of the study. The study had two groups of participants: 4 surgeons proficient in both robotic and advanced laparoscopic skills and 10 lay persons (nonsurgeons) who were given adequate time to train and familiarize themselves with the equipment. Running a 50-cm rope was the basic task. Advanced tasks included running a suture through predetermined points and intracorporeal knot tying with 3-0 silk. Trial completion times and errors, categorized into three groups (orientation, precision, and task), were recorded. The trial completion times for all the tasks, basic and advanced, in the two groups were not significantly different. Fewer orientation errors occurred in the nonsurgeon group during knot tying (p=0.03) and in both groups during suturing (p=0.0002) in the dual-monitor arm of the study. Differences in precision and task error were not significant. Using two camera views helps both surgeons and lay persons perform complex tasks with fewer errors. These results may be due to better awareness of the surgical field with regard to the location of the instruments, leading to better field orientation. This display setup has potential for use in complex minimally invasive surgeries such as esophagectomy and gastric bypass. This technique also would be applicable to open microsurgery.

  2. Cortical thickness estimation of the proximal femur from multi-view dual-energy X-ray absorptiometry (DXA)

    NASA Astrophysics Data System (ADS)

    Tsaousis, N.; Gee, A. H.; Treece, G. M.; Poole, K. E. S.

    2013-02-01

    Hip fracture is the leading cause of acute orthopaedic hospital admission amongst the elderly, with around a third of patients not surviving one year post-fracture. Although various preventative therapies are available, patient selection is difficult. The current state-of-the-art risk assessment tool (FRAX) ignores focal structural defects, such as cortical bone thinning, a critical component in characterizing hip fragility. Cortical thickness can be measured using CT, but this is expensive and involves a significant radiation dose. Instead, Dual-Energy X-ray Absorptiometry (DXA) is currently the preferred imaging modality for assessing hip fracture risk and is used routinely in clinical practice. Our ambition is to develop a tool to measure cortical thickness using multi-view DXA instead of CT. In this initial study, we work with digitally reconstructed radiographs (DRRs) derived from CT data as a surrogate for DXA scans: this enables us to compare directly the thickness estimates with the gold standard CT results. Our approach involves a model-based femoral shape reconstruction followed by a data-driven algorithm to extract numerous cortical thickness point estimates. In a series of experiments on the shaft and trochanteric regions of 48 proximal femurs, we validated our algorithm and established its performance limits using 20 views in the range 0°-171°: estimation errors were 0:19 +/- 0:53mm (mean +/- one standard deviation). In a more clinically viable protocol using four views in the range 0°-51°, where no other bony structures obstruct the projection of the femur, measurement errors were -0:07 +/- 0:79 mm.

  3. Dual methods and approximation concepts in structural synthesis

    NASA Technical Reports Server (NTRS)

    Fleury, C.; Schmit, L. A., Jr.

    1980-01-01

    Approximation concepts and dual method algorithms are combined to create a method for minimum weight design of structural systems. Approximation concepts convert the basic mathematical programming statement of the structural synthesis problem into a sequence of explicit primal problems of separable form. These problems are solved by constructing explicit dual functions, which are maximized subject to nonnegativity constraints on the dual variables. It is shown that the joining together of approximation concepts and dual methods can be viewed as a generalized optimality criteria approach. The dual method is successfully extended to deal with pure discrete and mixed continuous-discrete design variable problems. The power of the method presented is illustrated with numerical results for example problems, including a metallic swept wing and a thin delta wing with fiber composite skins.

  4. Dual-Telescope Multi-Channel Thermal-Infrared Radiometer for Outer Planet Fly-By Missions

    NASA Technical Reports Server (NTRS)

    Aslam, Shahid; Amato, Michael; Bowles, Neil; Calcutt, Simon; Hewagama, Tilak; Howard, Joseph; Howett, Carly; Hsieh, Wen-Ting; Hurford, Terry; Hurley, Jane; hide

    2016-01-01

    The design of a versatile dual-telescope thermal-infrared radiometer spanning the spectral wavelength range 8-200 microns, in five spectral pass bands, for outer planet fly-by missions is described. The dual- telescope design switches between a narrow-field-of-view and a wide-field-of-view to provide optimal spatial resolution images within a range of spacecraft encounters to the target. The switchable dual-field- of-view system uses an optical configuration based on the axial rotation of a source-select mirror along the optical axis. The optical design, spectral performance, radiometric accuracy, and retrieval estimates of the instrument are discussed. This is followed by an assessment of the surface coverage performance at various spatial resolutions by using the planned NASA Europa Mission 13-F7 fly-by trajectories as a case study.

  5. Dual view FIDA measurements on MAST

    NASA Astrophysics Data System (ADS)

    Michael, C. A.; Conway, N.; Crowley, B.; Jones, O.; Heidbrink, W. W.; Pinches, S.; Braeken, E.; Akers, R.; Challis, C.; Turnyanskiy, M.; Patel, A.; Muir, D.; Gaffka, R.; Bailey, S.

    2013-09-01

    A fast-ion deuterium alpha (FIDA) spectrometer was installed on MAST to measure radially resolved information about the fast-ion density and its distribution in energy and pitch angle. Toroidally and vertically directed collection lenses are employed, to detect both passing and trapped particle dynamics, and reference views are installed to subtract the background. This background is found to contain a substantial amount of passive FIDA emission driven by edge neutrals, and to depend delicately on viewing geometry. Results are compared with theoretical expectations based on the codes NUBEAM (for fast-ion distributions) and FIDASIM. Calibrating via the measured beam emission peaks, the toroidal FIDA signal profile agrees with classical simulations in magnetohydrodynamic quiescent discharges where the neutron rate is also classical. Long-lived modes (LLMs) and chirping modes decrease the core FIDA signal significantly, and the profile can be matched closely to simulations using anomalous diffusive transport; a spatially uniform diffusion coefficient is sufficient for chirping modes, while a core localized diffusion is better for a LLM. Analysis of a discharge with chirping mode activity shows a dramatic drop in the core FIDA signal and rapid increase in the edge passive signal at the onset of the burst indicating a very rapid redistribution towards the edge. Vertical-viewing measurements show a discrepancy with simulations at higher Doppler shifts when the neutron rate is classical, which, combined with the fact that the toroidal signals agree, means that the difference must be occurring for pitch angles near the trapped-passing boundary, although uncertainties in the background subtraction, which are difficult to assess, may contribute to this. Further evidence of an anomalous transport mechanism for these particles is provided by the fact that an increase of beam power does not increase the higher energy vertical FIDA signals, while the toroidal signals do increase.

  6. Benefits and Challenges of Dual-Earning: Perspectives of Successful Couples.

    ERIC Educational Resources Information Center

    Haddock, Shelley A.; Rattenborg, Karen

    2003-01-01

    Examines the benefits and challenges derived from the dual-earner lifestyle for couples who successfully balance family and work. Many therapists harbor negative and stereotypical assumptions of the quality of dual-earner family life, but the findings of this study are helpful in providing a more balanced, informed view of the possibilities of…

  7. Dual-telescope multi-channel thermal-infrared radiometer for outer planet fly-by missions

    NASA Astrophysics Data System (ADS)

    Aslam, Shahid; Amato, Michael; Bowles, Neil; Calcutt, Simon; Hewagama, Tilak; Howard, Joseph; Howett, Carly; Hsieh, Wen-Ting; Hurford, Terry; Hurley, Jane; Irwin, Patrick; Jennings, Donald E.; Kessler, Ernst; Lakew, Brook; Loeffler, Mark; Mellon, Michael; Nicoletti, Anthony; Nixon, Conor A.; Putzig, Nathaniel; Quilligan, Gerard; Rathbun, Julie; Segura, Marcia; Spencer, John; Spitale, Joseph; West, Garrett

    2016-11-01

    The design of a versatile dual-telescope thermal-infrared radiometer spanning the spectral wavelength range 8-200 μm, in five spectral pass bands, for outer planet fly-by missions is described. The dual-telescope design switches between a narrow-field-of-view and a wide-field-of-view to provide optimal spatial resolution images within a range of spacecraft encounters to the target. The switchable dual-field-of-view system uses an optical configuration based on the axial rotation of a source-select mirror along the optical axis. The optical design, spectral performance, radiometric accuracy, and retrieval estimates of the instrument are discussed. This is followed by an assessment of the surface coverage performance at various spatial resolutions by using the planned NASA Europa Mission 13-F7 fly-by trajectories as a case study.

  8. Direct social perception and dual process theories of mindreading.

    PubMed

    Herschbach, Mitchell

    2015-11-01

    The direct social perception (DSP) thesis claims that we can directly perceive some mental states of other people. The direct perception of mental states has been formulated phenomenologically and psychologically, and typically restricted to the mental state types of intentions and emotions. I will compare DSP to another account of mindreading: dual process accounts that posit a fast, automatic "Type 1" form of mindreading and a slow, effortful "Type 2" form. I will here analyze whether dual process accounts' Type 1 mindreading serves as a rival to DSP or whether some Type 1 mindreading can be perceptual. I will focus on Apperly and Butterfill's dual process account of mindreading epistemic states such as perception, knowledge, and belief. This account posits a minimal form of Type 1 mindreading of belief-like states called registrations. I will argue that general dual process theories fit well with a modular view of perception that is considered a kind of Type 1 process. I will show that this modular view of perception challenges and has significant advantages over DSP's phenomenological and psychological theses. Finally, I will argue that if such a modular view of perception is accepted, there is significant reason for thinking Type 1 mindreading of belief-like states is perceptual in nature. This would mean extending the scope of DSP to at least one type of epistemic state. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Dual energy CT with one full scan and a second sparse-view scan using structure preserving iterative reconstruction (SPIR)

    NASA Astrophysics Data System (ADS)

    Wang, Tonghe; Zhu, Lei

    2016-09-01

    Conventional dual-energy CT (DECT) reconstruction requires two full-size projection datasets with two different energy spectra. In this study, we propose an iterative algorithm to enable a new data acquisition scheme which requires one full scan and a second sparse-view scan for potential reduction in imaging dose and engineering cost of DECT. A bilateral filter is calculated as a similarity matrix from the first full-scan CT image to quantify the similarity between any two pixels, which is assumed unchanged on a second CT image since DECT scans are performed on the same object. The second CT image from reduced projections is reconstructed by an iterative algorithm which updates the image by minimizing the total variation of the difference between the image and its filtered image by the similarity matrix under data fidelity constraint. As the redundant structural information of the two CT images is contained in the similarity matrix for CT reconstruction, we refer to the algorithm as structure preserving iterative reconstruction (SPIR). The proposed method is evaluated on both digital and physical phantoms, and is compared with the filtered-backprojection (FBP) method, the conventional total-variation-regularization-based algorithm (TVR) and prior-image-constrained-compressed-sensing (PICCS). SPIR with a second 10-view scan reduces the image noise STD by a factor of one order of magnitude with same spatial resolution as full-view FBP image. SPIR substantially improves over TVR on the reconstruction accuracy of a 10-view scan by decreasing the reconstruction error from 6.18% to 1.33%, and outperforms TVR at 50 and 20-view scans on spatial resolution with a higher frequency at the modulation transfer function value of 10% by an average factor of 4. Compared with the 20-view scan PICCS result, the SPIR image has 7 times lower noise STD with similar spatial resolution. The electron density map obtained from the SPIR-based DECT images with a second 10-view scan has an

  10. Assimilation of AATSR, MERIS and MODIS Data in the Snowmelt Runoff Model (SRM) on the Upper Rio Grande (USA)

    NASA Astrophysics Data System (ADS)

    Bleiweiss, M. P.; Rampini, A.; Pepe, M.; Rango, A.; Steele, C.; Stein, W. L.; Schmugge, T.

    2008-12-01

    Current efforts for simulating or forecasting snowmelt are time-consuming and laborious; the AWARE project (A tool for monitoring and forecasting Available WAter REsource in mountain environments) has been motivated by the urgent need to facilitate the prediction of medium-term flows from snowmelt for an effective and sustainable water resources management. Its main goal is to provide innovative tools for monitoring and predicting water availability and distribution in drainage basins where snowmelt is a major component of the annual water balance. The particular objective of the effort reported here is to compare results obtained from the MODIS sensor on NASA Terra and Aqua satellite and next generation sensors AATSR and MERIS on board ESA Envisat satellite. The vehicle for this comparison is the AWARE Geoportal (http://www.aware- eu.info/eng/home.htm) which is a WWW implementation of the Snowmelt Runoff Model (SRM). The river basin chosen for analysis is the Upper Rio Grande of North America. The time period for analysis encompasses the Water Years 2005, 2006, and 2007 (October 2004 - September 2007). The reason for this is to ensure that data from all three sensors are available for use and to investigate variable climate conditions. A successful comparison between the various sensors will help demonstrate that the AWARE approach will facilitate future processing of several years' worth of snow cover data from a variety of sensors that covers large extremes in climate variability. This will allow greater success in developing forecasts and understanding of longer term climate change impacts.

  11. Dual-modality imaging with a ultrasound-gamma device for oncology

    NASA Astrophysics Data System (ADS)

    Polito, C.; Pellegrini, R.; Cinti, M. N.; De Vincentis, G.; Lo Meo, S.; Fabbri, A.; Bennati, P.; Cencelli, V. Orsolini; Pani, R.

    2018-06-01

    Recently, dual-modality systems have been developed, aimed to correlate anatomical and functional information, improving disease localization and helping oncological or surgical treatments. Moreover, due to the growing interest in handheld detectors for preclinical trials or small animal imaging, in this work a new dual modality integrated device, based on a Ultrasounds probe and a small Field of View Single Photon Emission gamma camera, is proposed.

  12. All-around viewing display system for group activity on life review therapy

    NASA Astrophysics Data System (ADS)

    Sakamoto, Kunio; Okumura, Mitsuru

    2009-10-01

    This paper describes 360 degree viewing display system that can be viewed from any direction. A conventional monitor display is viewed from one direction, i.e., the display has narrow viewing angle and observers cannot view the screen from the opposite side. To solve this problem, we developed the 360 degree viewing display for collaborative tasks on the round table. This developed 360 degree viewing system has a liquid crystal display screen and a 360 degree rotating table by motor. The principle is very simple. The screen of a monitor only rotates at a uniform speed, but the optical techniques are also utilized. Moreover, we have developed a floating 360 degree viewing display that can be viewed from any direction. This new viewing system has a display screen, a rotating table and dual parabolic mirrors. In order to float the only image screen above the table, the rotating mechanism works in the parabolic mirrors. Because the dual parabolic mirrors generate a "mirage" image over the upper mirror, observers can view a floating 2D image on the virtual screen in front of them. Then the observer can view a monitor screen at any position surrounding the round table.

  13. Dual-modality imaging of function and physiology

    NASA Astrophysics Data System (ADS)

    Hasegawa, Bruce H.; Iwata, Koji; Wong, Kenneth H.; Wu, Max C.; Da Silva, Angela; Tang, Hamilton R.; Barber, William C.; Hwang, Andrew B.; Sakdinawat, Anne E.

    2002-04-01

    Dual-modality imaging is a technique where computed tomography or magnetic resonance imaging is combined with positron emission tomography or single-photon computed tomography to acquire structural and functional images with an integrated system. The data are acquired during a single procedure with the patient on a table viewed by both detectors to facilitate correlation between the structural and function images. The resulting data can be useful for localization for more specific diagnosis of disease. In addition, the anatomical information can be used to compensate the correlated radionuclide data for physical perturbations such as photon attenuation, scatter radiation, and partial volume errors. Thus, dual-modality imaging provides a priori information that can be used to improve both the visual quality and the quantitative accuracy of the radionuclide images. Dual-modality imaging systems also are being developed for biological research that involves small animals. The small-animal dual-modality systems offer advantages for measurements that currently are performed invasively using autoradiography and tissue sampling. By acquiring the required data noninvasively, dual-modality imaging has the potential to allow serial studies in a single animal, to perform measurements with fewer animals, and to improve the statistical quality of the data.

  14. Application and Discussion of Dual Fluidized Bed Reactor in Biomass Energy Utilization

    NASA Astrophysics Data System (ADS)

    Guan, Haibin; Fan, Xiaoxu; Zhao, Baofeng; Yang, Liguo; Sun, Rongfeng

    2018-01-01

    As an important clean and renewable energy, biomass has a broad market prospect. The dual fluidized bed is widely used in biomass gasification technology, and has become an important way of biomass high-value utilization. This paper describes the basic principle of dual fluidized bed gasification, from the gas composition, tar content and thermal efficiency of the system point of view, analyzes and summarizes several typical dual fluidized bed biomass gasification technologies, points out the existence of gas mixing, the external heat source, catalyst development problems on gas. Finally, it is clear that the gasification of biomass in dual fluidized bed is of great industrial application and development prospect.

  15. Dual Enrollment from Two Points of View: Higher Education and K-12

    ERIC Educational Resources Information Center

    Kilgore, Wendy; Wagner, Ellen

    2017-01-01

    While dual enrollment fills a similar student success niche in both higher and K-12 education, the administrative perspectives of these two entities do not always align. This article highlights the groups' similarities and differences in perspective and proposes implications for practice.

  16. Sea Surface Temperature Records from the Along-Track Scanning Radiometers

    NASA Astrophysics Data System (ADS)

    Mutlow, C. T.; Smith, D. L.; Delderfield, J.; Llewellyn-Jones, D.

    2006-12-01

    Since the early 1990s ESA has flown Along Track Scanning Radiometer (ATSR) instruments on its ERS-1 and -2 satellites and is currently flying the Advanced ATSR instrument (AATSR) on its very successful Envisat mission; each successive sensor has been an incremental improvement over the last. The sensors have been specifically designed to provide the information urgently needed for the debate on climate change and global warming, as well as to produce properly calibrated image data sets for use in a wide range of EO studies. The ATSR instruments are a series of second generation space radiometers which build on the long heritage of the NOAA Advanced Very High Resolution Radiometers (AVHRR). Each ATSR exploits the multi-channel method pioneered in AVHRR but also uses new technology to improve instrument stability and calibration, detector signal to noise, and to provide observations of the same surface scene at two different angles. The novel feature of each ATSR, from which the sensor is derives its name, is its use of along-track scanning to reduce the effects of the atmosphere on surface measurements. This method obtains two observations of the scene through differing amounts of atmosphere; the "along track" view passes through a longer atmospheric path so is more affected by the atmosphere than the nadir view. ATSR-1 was launched on the ESA ERS-1 satellite on 17th July 1991, as the test-bed for the along track scanning concept using infrared channels at 1.6, 3.7, 10.8 and 12.0um. ATSR-1 continued to operate until the ERS-1 spacecraft was lost some 10 years after launch. The ATSR-2 and Advanced ATSR (AATSR) instruments are developments from the original ATSR-1, which in addition to the infrared channels; carry extra visible channels at 0.55, 0.67 and 0.87um for vegetation, cloud and aerosol remote sensing. ATSR-2 has operating on the ESA ERS-2 satellite since April 1995 and has provided over 10 years of data. The current operational sensor is AATSR flying on ESA

  17. Climate Trend Detection using Sea-Surface Temperature Data-sets from the (A)ATSR and AVHRR Space Sensors.

    NASA Astrophysics Data System (ADS)

    Llewellyn-Jones, D. T.; Corlett, G. K.; Remedios, J. J.; Noyes, E. J.; Good, S. A.

    2007-05-01

    Sea-Surface Temperature (SST) is an important indicator of global change, designated by GCOS as an essential Climate Variable (ECV). The detection of trends in Global SST requires rigorous measurements that are not only global, but also highly accurate and consistent. Space instruments can provide the means to achieve these required attributes in SST data. This paper presents an analysis of 15 years of SST data from two independent data sets, generated from the (A)ATSR and AVHRR series of sensors respectively. The analyses reveal trends of increasing global temperature between 0.13°C to 0.18 °C, per decade, closely matching that expected from some current predictions. A high level of consistency in the results from the two independent observing systems is seen, which gives increased confidence in data from both systems and also enables comparative analyses of the accuracy and stability of both data sets to be carried out. The conclusion is that these satellite SST data-sets provide important means to quantify and explore the processes of climate change. An analysis based upon singular value decomposition, allowing the removal of gross transitory disturbances, notably the El Niño, in order to examine regional areas of change other than the tropical Pacific, is also presented. Interestingly, although El Niño events clearly affect SST globally, they are found to have a non- significant (within error) effect on the calculated trends, which changed by only 0.01 K/decade when the pattern of El Niño and the associated variations was removed from the SST record. Although similar global trends were calculated for these two independent data sets, larger regional differences are noted. Evidence of decreased temperatures after the eruption of Mount Pinatubo in 1991 was also observed. The methodology demonstrated here can be applied to other data-sets, which cover long time-series observations of geophysical observations in order to characterise long-term change.

  18. Satellite remote sensing of aerosol and cloud properties over Eurasia

    NASA Astrophysics Data System (ADS)

    Sogacheva, Larisa; Kolmonen, Pekka; Saponaro, Giulia; Virtanen, Timo; Rodriguez, Edith; Sundström, Anu-Maija; Atlaskina, Ksenia; de Leeuw, Gerrit

    2015-04-01

    Satellite remote sensing provides the spatial distribution of aerosol and cloud properties over a wide area. In our studies large data sets are used for statistical studies on aerosol and cloud interaction in an area over Fennoscandia, the Baltic Sea and adjacent regions over the European mainland. This area spans several regimes with different influences on aerosol cloud interaction such as a the transition from relative clean air over Fennoscandia to more anthropogenically polluted air further south, and the influence maritime air over the Baltic and oceanic air advected from the North Atlantic. Anthropogenic pollution occurs in several parts of the study area, and in particular near densely populated areas and megacities, but also in industrialized areas and areas with dense traffic. The aerosol in such areas is quite different from that produced over the boreal forest and has different effects on air quality and climate. Studies have been made on the effects of aerosols on air quality and on the radiation balance in China. The aim of the study is to study the effect of these different regimes on aerosol-cloud interaction using a large aerosol and cloud data set retrieved with the (Advanced) Along Track Scanning Radiometer (A)ATSR Dual View algorithm (ADV) further developed at Finnish Meteorological Institute and aerosol and cloud data provided by MODIS. Retrieval algorithms for aerosol and clouds have been developed for the (A)ATSR, consisting of a series of instruments of which we use the second and third one: ATSR-2 which flew on the ERS-2 satellite (1995-2003) and AATSR which flew on the ENVISAT satellite (2002-2012) (both from the European Space Agency, ESA). The ADV algorithm provides aerosol data on a global scale with a default resolution of 10x10km2 (L2) and an aggregate product on 1x1 degree (L3). Optional, a 1x1 km2 retrieval products is available over smaller areas for specific studies. Since for the retrieval of AOD no prior knowledge is needed on

  19. [The dual process model of addiction. Towards an integrated model?].

    PubMed

    Vandermeeren, R; Hebbrecht, M

    2012-01-01

    Neurobiology and cognitive psychology have provided us with a dual process model of addiction. According to this model, behavior is considered to be the dynamic result of a combination of automatic and controlling processes. In cases of addiction the balance between these two processes is severely disturbed. Automated processes will continue to produce impulses that ensure the continuance of addictive behavior. Weak, reflective or controlling processes are both the reason for and the result of the inability to forgo addiction. To identify features that are common to current neurocognitive insights into addiction and psychodynamic views on addiction. The picture that emerges from research is not clear. There is some evidence that attentional bias has a causal effect on addiction. There is no evidence that automatic associations have a causal effect, but there is some evidence that automatic action-tendencies do have a causal effect. Current neurocognitive views on the dual process model of addiction can be integrated with an evidence-based approach to addiction and with psychodynamic views on addiction.

  20. Conflict Monitoring in Dual Process Theories of Thinking

    ERIC Educational Resources Information Center

    De Neys, Wim; Glumicic, Tamara

    2008-01-01

    Popular dual process theories have characterized human thinking as an interplay between an intuitive-heuristic and demanding-analytic reasoning process. Although monitoring the output of the two systems for conflict is crucial to avoid decision making errors there are some widely different views on the efficiency of the process. Kahneman…

  1. Dual-resolution image reconstruction for region-of-interest CT scan

    NASA Astrophysics Data System (ADS)

    Jin, S. O.; Shin, K. Y.; Yoo, S. K.; Kim, J. G.; Kim, K. H.; Huh, Y.; Lee, S. Y.; Kwon, O.-K.

    2014-07-01

    In ordinary CT scan, so called full field-of-view (FFOV) scan, in which the x-ray beam span covers the whole section of the body, a large number of projections are necessary to reconstruct high resolution images. However, excessive x-ray dose is a great concern in FFOV scan. Region-of-interest (ROI) scan is a method to visualize the ROI in high resolution while reducing the x-ray dose. But, ROI scan suffers from bright-band artifacts which may hamper CT-number accuracy. In this study, we propose an image reconstruction method to eliminate the band artifacts in the ROI scan. In addition to the ROI scan with high sampling rate in the view direction, we get FFOV projection data with much lower sampling rate. Then, we reconstruct images in the compressed sensing (CS) framework with dual resolutions, that is, high resolution in the ROI and low resolution outside the ROI. For the dual-resolution image reconstruction, we implemented the dual-CS reconstruction algorithm in which data fidelity and total variation (TV) terms were enforced twice in the framework of adaptive steepest descent projection onto convex sets (ASD-POCS). The proposed method has remarkably reduced the bright-band artifacts at around the ROI boundary, and it has also effectively suppressed the streak artifacts over the entire image. We expect the proposed method can be greatly used for dual-resolution imaging with reducing the radiation dose, artifacts and scan time.

  2. Sensitivity of dual-wall structures under hypervelocity impact to multi-layer thermal insulation thickness and placement

    NASA Astrophysics Data System (ADS)

    Schonberg, William P.

    1993-04-01

    Results are presented from an experimental study in which Al dual-wall structures were tested, under various high-speed impact conditions, with a view to the effect of multilayer insulation thickness and location on perforation resistance. Attention is given to comparisons of the damage sustained by dual-wall systems with multilayer insulation blankets of various thicknesses and at various locations within the dual-wall system, under comparable impact loading conditions. The placement of the insulation has a significant effect on the ballistic limit of the dual-wall structures considered, while reducing insulation thickness by as much as a third did not.

  3. Towards Consistent Aerosol and Cloud Climate Data Records from the Along Track Scanning Radiometer instruments

    NASA Astrophysics Data System (ADS)

    Thomas, G.

    2015-12-01

    The ESA Climate Change Initiative (CCI) programme has provided a mechanism for the production of new long-term data records of essential climate variables (ECVs) defined by WMO Global Climate Observing System (GCOS). These include consistent cloud (from the MODIS, AVHRR, ATSR-2 and AATSR instruments) and aerosol (from ATSR-2 and AATSR) products produced using the Optimal Retrieval of Aerosol and Cloud (ORAC) scheme. This talk will present an overview of the newly produced ORAC cloud and aerosol datasets, their evaluation and a joint aerosol-cloud product produced for the 1995-2012 ATSR-2-AATSR data record.

  4. Dual-surface dielectric depth detector for holographic millimeter-wave security scanners

    NASA Astrophysics Data System (ADS)

    McMakin, Douglas L.; Keller, Paul E.; Sheen, David M.; Hall, Thomas E.

    2009-05-01

    The Transportation Security Administration (TSA) is presently deploying millimeter-wave whole body scanners at over 20 airports in the United States. Threats that may be concealed on a person are displayed to the security operator of this scanner. "Passenger privacy is ensured through the anonymity of the image. The officer attending the passenger cannot view the image, and the officer viewing the image is remotely located and cannot see the passenger. Additionally, the image cannot be stored, transmitted or printed and is deleted immediately after being viewed. Finally, the facial area of the image has been blurred to further ensure privacy." Pacific Northwest National Laboratory (PNNL) originated research into this novel security technology which has been independently commercialized by L-3 Communications, SafeView, Inc. PNNL continues to perform fundamental research into improved software techniques which are applicable to the field of holographic security screening technology. This includes performing significant research to remove human features from the imagery. Both physical and software imaging techniques have been employed. The physical imaging techniques include polarization diversity illumination and reception, dual frequency implementation, and high frequency imaging at 100 GHz. This paper will focus on a software privacy technique using a dual surface dielectric depth detector method.

  5. The dilemma of dual use biological research: Polish perspective.

    PubMed

    Czarkowski, Marek

    2010-03-01

    Biological research with legitimate scientific purpose that may be misused to pose a biological threat to public health and/or national security is termed dual use. In Poland there are adequate conditions for conducting experiments that could be qualified as dual use research, and therefore, a risk of attack on Poland or other countries exists. Optimal solutions for limiting such threats are required, and the national system of biosecurity should enable early, reliable, and complete identification of this type of research. Scientists should have a fundamental role in this process, their duty being to immediately, upon identification, report research with dual use potential. An important entity in the identification system of dual use research should also be the Central Register of Biological and Biomedical Research, which gathers information about all biological and biomedical research being conducted in a given country. Publishers, editors, and review committees of journals and other scientific publications should be involved in evaluating results of clinical trials. The National Council of Biosecurity should be the governmental institution responsible for developing a system of dual use research threat prevention. Its role would be to develop codes of conduct, form counsel of expertise, and monitor the problem at national level, while the Dual Use Research Committee would be responsible for individual cases. In Poland, current actions aiming to provide biological safety were based on developing and passing an act about genetically modified organisms (GMO's) and creating a GMO Committee. Considering experiences of other nations, one should view these actions as fragmentary, and thus insufficient protection against dual use research threats.

  6. Single lens system for forward-viewing navigation and scanning side-viewing optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Tate, Tyler H.; McGregor, Davis; Barton, Jennifer K.

    2017-02-01

    The optical design for a dual modality endoscope based on piezo scanning fiber technology is presented including a novel technique to combine forward-viewing navigation and side viewing OCT. Potential applications include navigating body lumens such as the fallopian tube, biliary ducts and cardiovascular system. A custom cover plate provides a rotationally symmetric double reflection of the OCT beam to deviate and focus the OCT beam out the side of the endoscope for cross-sectional imaging of the tubal lumen. Considerations in the choice of the scanning fiber are explored and a new technique to increase the divergence angle of the scanning fiber to improve system performance is presented. Resolution and the necessary scanning density requirements to achieve Nyquist sampling of the full image are considered. The novel optical design lays the groundwork for a new approach integrating side-viewing OCT into multimodality endoscopes for small lumen imaging. KEYWORDS:

  7. Dual-fuel, dual-throat engine preliminary analysis

    NASA Technical Reports Server (NTRS)

    Obrien, C. J.

    1979-01-01

    A propulsion system analysis of the dual fuel, dual throat engine for launch vehicle applications was conducted. Basic dual throat engine characterization data were obtained to allow vehicle optimization studies to be conducted. A preliminary baseline engine system was defined.

  8. Dual-Targeting of AR and Akt Pathways by Berberine in Castration-Resistant Prostate Cancer

    DTIC Science & Technology

    2016-10-01

    Award Number: W81XWH-12-1-0275 TITLE: Dual-Targeting of AR and Akt Pathways by Berberine in Castration-Resistant Prostate Cancer PRINCIPAL...Public Release; Distribution Unlimited The views, opinions and/or findings contained in this report are those of the author(s) and should not be...TITLE AND SUBTITLE 5a. CONTRACT NUMBER Dual-Targeting of AR and Akt Pathways by Berberine in Castration- Resistant Prostate Cancer 5b. GRANT NUMBER

  9. Building a Framework for a Dual Task Taxonomy

    PubMed Central

    McIsaac, Tara L.; Lamberg, Eric M.; Muratori, Lisa M.

    2015-01-01

    The study of dual task interference has gained increasing attention in the literature for the past 35 years, with six MEDLINE citations in 1979 growing to 351 citations indexed in 2014 and a peak of 454 cited papers in 2013. Increasingly, researchers are examining dual task cost in individuals with pathology, including those with neurodegenerative diseases. While the influence of these papers has extended from the laboratory to the clinic, the field has evolved without clear definitions of commonly used terms and with extreme variations in experimental procedures. As a result, it is difficult to examine the interference literature as a single body of work. In this paper we present a new taxonomy for classifying cognitive-motor and motor-motor interference within the study of dual task behaviors that connects traditional concepts of learning and principles of motor control with current issues of multitasking analysis. As a first step in the process we provide an operational definition of dual task, distinguishing it from a complex single task. We present this new taxonomy, inclusive of both cognitive and motor modalities, as a working model; one that we hope will generate discussion and create a framework from which one can view previous studies and develop questions of interest. PMID:25961027

  10. Dual algebraic formulation of differential GPS

    NASA Astrophysics Data System (ADS)

    Lannes, A.; Dur, S.

    2003-05-01

    A new approach to differential GPS is presented. The corresponding theoretical framework calls on elementary concepts of algebraic graph theory. The notion of double difference, which is related to that of closure in the sense of Kirchhoff, is revisited in this context. The Moore-Penrose pseudo-inverse of the closure operator plays a key role in the corresponding dual formulation. This approach, which is very attractive from a conceptual point of view, sheds a new light on the Teunissen formulation.

  11. Dual exposure view of exterior and interior of Apollo Mission simulator

    NASA Image and Video Library

    1967-08-01

    S67-50585 (1967) --- This is an intentional double exposure showing the Apollo Mission Simulator in the Mission Simulation and Training Facility, Building 5 at the Manned Spacecraft Center. In the exterior view astronauts William A. Anders, Michael Collins, and Frank Borman (reading from top of stairs) are about to enter the simulator. The interior view shows the three astronauts in the simulator. They are (left to right) Borman, Collins, and Anders. Photo credit: NASA

  12. Sea Temperature Fiducial Reference Measurements for the Validation and Data Gap Bridging of Satellite SST Data Products

    NASA Astrophysics Data System (ADS)

    Wimmer, Werenfrid

    2016-08-01

    The Infrared Sea surface temperature Autonomous Radiometer (ISAR) was developed to provide reference data for the validation of satellite Sea Surface Temperature at the Skin interface (SSTskin) temperature data products, particularly the Advanced Along Track Scanning Radiometer (AATSR). Since March 2004 ISAR instruments have been deployed nearly continuously on ferries crossing the English Channel and the Bay of Biscay, between Portsmouth (UK) and Bilbao/Santander (Spain). The resulting twelve years of ISAR data, including an individual uncertainty estimate for each SST record, are calibrated with traceability to national standards (National Institute of Standards and Technology, USA (NIST) and National Physical Laboratory, Teddigton, UK (NPL), Fiducial Reference Measurements for satellite derived surface temperature product validation (FRM4STS)). They provide a unique independent in situ reference dataset against which to validate satellite derived products. We present results of the AATSR validation, and show the use of ISAR fiducial reference measurements as a common traceable validation data source for both AATSR and Sea and Land Surface Temperature Radiometer (SLSTR). ISAR data were also used to review performance of the Operational Sea Surface Temperature and Sea Ice Analysis (OSTIA) Sea Surface Temperature (SST) analysis before and after the demise of ESA Environmental Satellite (Envisat) when AATSR inputs ceased This demonstrates use of the ISAR reference data set for validating the SST climatologies that will bridge the data gap between AATSR and SLSTR.

  13. The dual-use problem, scientific isolationism and the division of moral labour.

    PubMed

    Douglas, Thomas

    2014-01-01

    The dual-use problem is an ethical quandary sometimes faced by scientists and others in a position to influence the creation or dissemination of scientific knowledge. It arises when (i) an agent is considering whether to pursue some project likely to result in the creation or dissemination of scientific knowledge, (ii) that knowledge could be used in both morally desirable and morally undesirable ways, and (iii) the risk of undesirable use is sufficiently high that it is not clear that the agent may permissibly pursue the project or policy. Agents said to be faced with dual-use problems have frequently responded by appealing to a view that I call scientific isolationism. This is, roughly, the view that scientific decisions may be made without morally appraising the likely uses of the scientific knowledge whose production or dissemination is at stake. I consider whether scientific isolationism can be justified in a form that would indeed provide a way out of dual-use problems. I first argue for a presumption against a strong form of isolationism, and then examine four arguments that might be thought to override this presumption. The most promising of these arguments appeals to the idea of a division of moral labour, but I argue that even this argument can sustain at most a highly attenuated form of scientific isolationism and that this variant of isolationism has little practical import for discussions of the dual-use problem.

  14. Depth Perception In Remote Stereoscopic Viewing Systems

    NASA Technical Reports Server (NTRS)

    Diner, Daniel B.; Von Sydow, Marika

    1989-01-01

    Report describes theoretical and experimental studies of perception of depth by human operators through stereoscopic video systems. Purpose of such studies to optimize dual-camera configurations used to view workspaces of remote manipulators at distances of 1 to 3 m from cameras. According to analysis, static stereoscopic depth distortion decreased, without decreasing stereoscopitc depth resolution, by increasing camera-to-object and intercamera distances and camera focal length. Further predicts dynamic stereoscopic depth distortion reduced by rotating cameras around center of circle passing through point of convergence of viewing axes and first nodal points of two camera lenses.

  15. Possibilities, intentions and threats: dual use in the life sciences reconsidered.

    PubMed

    van der Bruggen, Koos

    2012-12-01

    Due to the terrorist attacks of 9/11 and the anthrax letters of a few weeks later, the concept of dual use has spread widely in the life sciences during the past decade. This article is aimed at a clarification of the dual use concept and its scope of application for the life sciences. Such a clarification would greatly facilitate the work of policymakers seeking to ensure security while avoiding undesirable interventions of government in the conduct of science. The article starts with an overview of the main developments in life sciences in relation to dual use. This is illustrated by discussions on synthetic biology and dual use. The findings lead to a reconsideration of the dual use concept. An area in need of further attention is to what extent threats and intentions should have impact on the definition of dual use. Possible threats are analyzed against the background of the phenomenon of securitization of health care and life sciences: considering these sectors of society in security terms. Some caveats that should be taken into account in a dual use policy are described. An acceptable, adequate and applicable definition of the dual use concept could help researchers, universities, companies and policy makers. Such a definition should build upon, but go beyond, the view developed in the influential Fink-report, which concentrates on the so-called 'experiments of concern', e.g. experiments that enhance the virulence of pathogens (National Research Council of the National Academies 2004) It will be argued that-in addition to these more technical aspects-a definition of dual use should include the aspect of threats and intentions.

  16. Jean Piaget's Theory of Equilibration Applied to Dual Language Development.

    ERIC Educational Resources Information Center

    Chavez, Luisa C.

    This paper suggests that one possibility for the lack of study emphasis and unity of understanding in the area of dual language development is that language study in general shows some serious gaps and reveals a need for viewing language development as a holistic endeavor. Noting the failures of Skinnerian theory, Chomskian theory, Soviet…

  17. Development and characterization of a dual-energy subtraction imaging system for chest radiography based on CsI:Tl amorphous silicon flat-panel technology

    NASA Astrophysics Data System (ADS)

    Sabol, John M.; Avinash, Gopal B.; Nicolas, Francois; Claus, Bernhard E. H.; Zhao, Jianguo; Dobbins, James T., III

    2001-06-01

    Dual-energy subtraction imaging increases the sensitivity and specificity of pulmonary nodule detection in chest radiography by reducing the contrast of overlying bone structures. Recent development of a fast, high-efficiency detector enables dual-energy imaging to be integrated into the traditional workflow. We have modified a GE RevolutionTM XQ/i chest imaging system to construct a dual-energy imaging prototype system. Here we describe the operating characteristics of this prototype and evaluate image quality. Empirical results show that the dual-energy CNR is maximized if the dose is approximately equal for both high and low energy exposures. Given the high detector DQE, and allocation of dose between the two views, we can acquire dual-energy PA and conventional lateral images with total dose equivalent to a conventional two-view film chest exam. Calculations have shown that the dual-exposure technique has superior CNR and tissue cancellation than single-exposure CR systems. Clinical images obtained on a prototype dual-energy imaging system show excellent tissue contrast cancellation, low noise, and modest motion artefacts. In summary, a prototype dual-energy system has been constructed which enables rapid, dual-exposure imaging of the chest using a commercially available high-efficiency, flat-panel x-ray detector. The quality of the clinical images generated with this prototype exceeds that of CR techniques and demonstrates the potential for improved detection and characterization of lung disease through dual-energy imaging.

  18. High-resolution velocity measurements using dual-view tomographic digital holographic microscopy

    NASA Astrophysics Data System (ADS)

    Gao, Jian; Agarwal, Karuna; Katz, Joseph

    2017-11-01

    A recently developed two-view tomographic digital holographic microscopy (DHM) system is used for measuring the flow around a pair of cubes with height of 90 wall units immersed in the inner layer of a turbulent channel flow at Reτ = 2500. Matching of the two views at 1- μm precision is achieved by implementing a self-calibration procedure that determines the three-dimensional, three-component (3D3C) distortion function, which corrects the geometric mapping. The procedure has been tested using distorted synthetic particle fields, and then implemented on experimental data. The two views are used to overcome the reduced accuracy of DHM in the axial direction of the reference beam due to elongation of the reconstructed traces. Multiplying the two precisely-matched 3D intensity fields is used for truncating the elongated traces. The velocity distributions are obtained by 3D particle tracking guided by 3D cross-correlation of the truncated intensity fields along with other size/shape/smoothness constraints. As demonstrated by how divergence-free the data is, the resulting 3D3C velocity field is substantially more accurate than results obtained from single-view DHM. Results show that the cube is surrounded by a vorticity ``canopy'' that extends from upstream of its front surface to the separated region in its near wake. Nearly axial necklace vortices remain confined to the near wall region between the cubes, but expand rapidly behind them. Funded by NSF and ONR.

  19. Dual Credit/Dual Enrollment and Data Driven Policy Implementation

    ERIC Educational Resources Information Center

    Lichtenberger, Eric; Witt, M. Allison; Blankenberger, Bob; Franklin, Doug

    2014-01-01

    The use of dual credit has been expanding rapidly. Dual credit is a college course taken by a high school student for which both college and high school credit is given. Previous studies provided limited quantitative evidence that dual credit/dual enrollment is directly connected to positive student outcomes. In this study, predictive statistics…

  20. Animations Need Narrations: An Experimental Test of a Dual-Coding Hypothesis.

    ERIC Educational Resources Information Center

    Mayer, Richard E.; Anderson, Richard B.

    1991-01-01

    In two experiments, 102 mechanically naive college students viewed an animation on bicycle tire pump operation with a verbal description before or during the animation or without description. Improved performance of those receiving description during the animation supports a dual-coding hypothesis of connections between visual and verbal stimuli.…

  1. Parents' Working Hours: Adolescent Children's Views and Experiences

    ERIC Educational Resources Information Center

    Lewis, Jane; Noden, Philip; Sarre, Sophie

    2008-01-01

    As dual-earner families have become the norm, the different kinds of "time" children spend with parents has become an important issue. We use the 2000 Time Use Survey to identify adolescent children spending time alone at home, and interviews with 50 children aged 14 and 15 to explore young people's experiences. We investigate their views on their…

  2. Attitudinal Perspectives: A Factor to Implementation of a Dual Language Program

    ERIC Educational Resources Information Center

    Whitacre, Michael

    2015-01-01

    The central focus of this study was to determine the overall perceptions of school administrators, and the district bilingual coordinator on transferring theory to classroom practice, implementation, as viewed by those involved in the implementation process of the Gómez and Gómez Model of Dual Language Education. Responses were solicited from…

  3. Superlinear variant of the dual affine scaling algorithm

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Luz, C.; Cardosa, D.

    1994-12-31

    The affine scaling methods introduced by Dikin are generally considered the most efficient interior point algorithms from a computational point of view. However, it is actually an open question to know whether there is a polynomial affine scaling algorithm. This fact has motivated many investigations efforts and led to several convergence results. This is the case of the recently obtained results by Tsuchiya, Tseng and Luo and Tsuchiya and Muramatsu which, unlike the pioneering Dikin`s convergence result, do not require any non degeneracy assumption. This paper presents a new variant of the dual affine scaling algorithm for Linear Programming that,more » in a finite number of iterations, determines a primal-dual pair of optimal solutions. It is also shown the superlinear convergence of that variant without requiring any non degeneracy assumption.« less

  4. A dual cone-beam CT system for image guided radiotherapy: initial performance characterization.

    PubMed

    Li, Hao; Giles, William; Bowsher, James; Yin, Fang-Fang

    2013-02-01

    The purpose of this study is to evaluate the performance of a recently developed benchtop dual cone-beam computed tomography (CBCT) system with two orthogonally placed tube∕detector sets. The benchtop dual CBCT system consists of two orthogonally placed 40 × 30 cm flat-panel detectors and two conventional x-ray tubes with two individual high-voltage generators sharing the same rotational axis. The x-ray source to detector distance is 150 cm and x-ray source to rotational axis distance is 100 cm for both subsystems. The objects are scanned through 200° of rotation. The dual CBCT system utilized 110° of projection data from one detector and 90° from the other while the two individual single CBCTs utilized 200° data from each detector. The system performance was characterized in terms of uniformity, contrast, spatial resolution, noise power spectrum, and CT number linearity. The uniformities, within the axial slice and along the longitudinal direction, and noise power spectrum were assessed by scanning a water bucket; the contrast and CT number linearity were measured using the Catphan phantom; and the spatial resolution was evaluated using a tungsten wire phantom. A skull phantom and a ham were also scanned to provide qualitative evaluation of high- and low-contrast resolution. Each measurement was compared between dual and single CBCT systems. Compared to single CBCT, the dual CBCT presented: (1) a decrease in uniformity by 1.9% in axial view and 1.1% in the longitudinal view, as averaged for four energies (80, 100, 125, and 150 kVp); (2) comparable or slightly better contrast (0∼25 HU) for low-contrast objects and comparable contrast for high-contrast objects; (3) comparable spatial resolution; (4) comparable CT number linearity with R(2) ≥ 0.99 for all four tested energies; (5) lower noise power spectrum in magnitude. Dual CBCT images of the skull phantom and the ham demonstrated both high-contrast resolution and good soft-tissue contrast. The

  5. WE-EF-207-07: Dual Energy CT with One Full Scan and a Second Sparse-View Scan Using Structure Preserving Iterative Reconstruction (SPIR)

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wang, T; Zhu, L

    Purpose: Conventional dual energy CT (DECT) reconstructs CT and basis material images from two full-size projection datasets with different energy spectra. To relax the data requirement, we propose an iterative DECT reconstruction algorithm using one full scan and a second sparse-view scan by utilizing redundant structural information of the same object acquired at two different energies. Methods: We first reconstruct a full-scan CT image using filtered-backprojection (FBP) algorithm. The material similarities of each pixel with other pixels are calculated by an exponential function about pixel value differences. We assume that the material similarities of pixels remains in the second CTmore » scan, although pixel values may vary. An iterative method is designed to reconstruct the second CT image from reduced projections. Under the data fidelity constraint, the algorithm minimizes the L2 norm of the difference between pixel value and its estimation, which is the average of other pixel values weighted by their similarities. The proposed algorithm, referred to as structure preserving iterative reconstruction (SPIR), is evaluated on physical phantoms. Results: On the Catphan600 phantom, SPIR-based DECT method with a second 10-view scan reduces the noise standard deviation of a full-scan FBP CT reconstruction by a factor of 4 with well-maintained spatial resolution, while iterative reconstruction using total-variation regularization (TVR) degrades the spatial resolution at the same noise level. The proposed method achieves less than 1% measurement difference on electron density map compared with the conventional two-full-scan DECT. On an anthropomorphic pediatric phantom, our method successfully reconstructs the complicated vertebra structures and decomposes bone and soft tissue. Conclusion: We develop an effective method to reduce the number of views and therefore data acquisition in DECT. We show that SPIR-based DECT using one full scan and a second 10-view scan

  6. Optical modeling of volcanic ash particles using ellipsoids

    NASA Astrophysics Data System (ADS)

    Merikallio, Sini; Muñoz, Olga; Sundström, Anu-Maija; Virtanen, Timo H.; Horttanainen, Matti; de Leeuw, Gerrit; Nousiainen, Timo

    2015-05-01

    The single-scattering properties of volcanic ash particles are modeled here by using ellipsoidal shapes. Ellipsoids are expected to improve the accuracy of the retrieval of aerosol properties using remote sensing techniques, which are currently often based on oversimplified assumptions of spherical ash particles. Measurements of the single-scattering optical properties of ash particles from several volcanoes across the globe, including previously unpublished measurements from the Eyjafjallajökull and Puyehue volcanoes, are used to assess the performance of the ellipsoidal particle models. These comparisons between the measurements and the ellipsoidal particle model include consideration of the whole scattering matrix, as well as sensitivity studies on the point of view of the Advanced Along Track Scanning Radiometer (AATSR) instrument. AATSR, which flew on the ENVISAT satellite, offers two viewing directions but no information on polarization, so usually only the phase function is relevant for interpreting its measurements. As expected, ensembles of ellipsoids are able to reproduce the observed scattering matrix more faithfully than spheres. Performance of ellipsoid ensembles depends on the distribution of particle shapes, which we tried to optimize. No single specific shape distribution could be found that would perform superiorly in all situations, but all of the best-fit ellipsoidal distributions, as well as the additionally tested equiprobable distribution, improved greatly over the performance of spheres. We conclude that an equiprobable shape distribution of ellipsoidal model particles is a relatively good, yet enticingly simple, approach for modeling volcanic ash single-scattering optical properties.

  7. Dual nozzle aerodynamic and cooling analysis study. [dual throat and dual expander nozzles

    NASA Technical Reports Server (NTRS)

    Meagher, G. M.

    1980-01-01

    Geometric, aerodynamic flow field, performance prediction, and heat transfer analyses are considered for two advanced chamber nozzle concepts applicable to Earth-to-orbit engine systems. Topics covered include improvements to the dual throat aerodynamic and performance prediction program; geometric and flow field analyses of the dual expander concept; heat transfer analysis of both concepts, and engineering analysis of data from the NASA/MSFC hot-fire testing of a dual throat thruster model thrust chamber assembly. Preliminary results obtained are presented in graphs.

  8. An integrated treatment model for dual diagnosis of psychosis and addiction.

    PubMed

    Minkoff, K

    1989-10-01

    A model that integrates the treatment of patients with a dual diagnosis of psychosis and addiction has been developed on a general hospital psychiatric unit. The model emphasizes the parallels between the standard biopsychosocial illness-and-rehabilitation model for treatment of serious psychiatric disorders and the 12-step disease-and-recovery model of Alcoholics Anonymous for treatment of addiction. Dual-diagnosis patients are viewed as having two primary, chronic, biologic mental illnesses, each requiring specific treatment to stabilize acute symptoms and engage the patient in a recovery process. An integrated treatment program is described, as are the steps taken to alleviate psychiatric clinicians' concerns about patient involvement in AA and addiction clinicians' discomfort with patients' use of medication.

  9. Novel dual small-molecule HIV inhibitors: scaffolds and discovery strategies.

    PubMed

    Song, Anran; Yu, Haiqing; Wang, Changyuan; Zhu, Xingqi; Liu, Kexin; Ma, Xiaodong

    2015-01-01

    Searching for safe and effective treatments for HIV infection is still a great challenge worldwide in spite of the 27 marketed anti-HIV drugs and the powerful highly active antiretroviral therapy (HAART). As a promising prospect for generation of new HIV therapy drugs, multiple ligands (MDLs) were greatly focused on recently due to their lower toxicity, simplified dosing and patient adherence than single-target drugs. Till now, by disrupting two active sites or steps of HIV replications, a number of HIV dual inhibitors, such as CD4-gssucap120 inhibitors, CXCR4-gp20 inhibitors, RT-CXCR4 inhibitors, RT-protease inhibitors, RT-integrase inhibitors, and RTassociated functions inhibitors have been identified. Generally, these dual inhibitors were discovered mainly through screening approaches and design strategies. Of these compounds, the molecules bearing small skeletons exhibited strong anti-HIV activity and aroused great attention recently. Reviewing the progress of the dual small-molecule HIV inhibitors from the point of view of their scaffolds and discovery strategies will provide valuable information for producing more effective anti-HIV drugs. In this regard, novel dual small-molecule HIV inhibitors were illustrated, and their discovery paradigms as the major contents were also summarized in this manuscript.

  10. Grating Oriented Line-Wise Filtration (GOLF) for Dual-Energy X-ray CT

    NASA Astrophysics Data System (ADS)

    Xi, Yan; Cong, Wenxiang; Harrison, Daniel; Wang, Ge

    2017-12-01

    In medical X-ray Computed Tomography (CT), the use of two distinct X-ray source spectra (energies) allows dose-reduction and material discrimination relative to that achieved with only one source spectrum. Existing dual-energy CT methods include source kVp-switching, double-layer detection, dual-source gantry, and two-pass scanning. Each method suffers either from strong spectral correlation or patient-motion artifacts. To simultaneously address these problems, we propose to improve CT data acquisition with the Grating Oriented Line-wise Filtration (GOLF) method, a novel X-ray filter that is placed between the source and patient. GOLF uses a combination of absorption and filtering gratings that are moved relative to each other and in synchronization with the X-ray tube kVp-switching process and/or the detector view-sampling process. Simulation results show that GOLF can improve the spectral performance of kVp-switching to match that of dual-source CT while avoiding patient motion artifacts and dual imaging chains. Although significant flux is absorbed by this pre-patient filter, the proposed GOLF method is a novel path for cost-effectively extracting dual-energy or multi-energy data and reducing radiation dose with or without kVp switching.

  11. Grating Oriented Line-Wise Filtration (GOLF) for Dual-Energy X-ray CT

    PubMed Central

    Xi, Yan; Cong, Wenxiang; Harrison, Daniel

    2017-01-01

    In medical X-ray Computed Tomography (CT), the use of two distinct X-ray source spectra (energies) allows dose-reduction and material discrimination relative to that achieved with only one source spectrum. Existing dual-energy CT methods include source kVp-switching, double-layer detection, dual-source gantry, and two-pass scanning. Each method suffers either from strong spectral correlation or patient-motion artifacts. To simultaneously address these problems, we propose to improve CT data acquisition with the Grating Oriented Line-wise Filtration (GOLF) method, a novel X-ray filter that is placed between the source and patient. GOLF uses a combination of absorption and filtering gratings that are moved relative to each other and in synchronization with the X-ray tube kVp-switching process and/or the detector view-sampling process. Simulation results show that GOLF can improve the spectral performance of kVp-switching to match that of dual-source CT while avoiding patient motion artifacts and dual imaging chains. Although significant flux is absorbed by this pre-patient filter, the proposed GOLF method is a novel path for cost-effectively extracting dual-energy or multi-energy data and reducing radiation dose with or without kVp switching. PMID:29333113

  12. Dual mode scanner-tracker

    NASA Astrophysics Data System (ADS)

    Mongeon, R. J.

    1984-11-01

    The beam of a laser radar is moved over the field of view by means of a pair of scanner/trackers arranged in cascade along the laser beam. One of the scanner/trackers operates at high speed, with high resolution and a wide field and is located in the demagnified portion of the laser beam. The two scanner/trackers complement each other to achieve high speed, high resolution scanning as well as tracking of moving targets. A beam steering telescope for an airborne laser radar which incorporates the novel dual mode scanner/tracker is also shown. The other scanner/tracker operates at low speed with low resolution and a wide field and is located in the magnified portion of the laser beam.

  13. Toward an understanding of the neural mechanisms underlying dual-task performance: Contribution of comparative approaches using animal models.

    PubMed

    Watanabe, Kei; Funahashi, Shintaro

    2018-01-01

    The study of dual-task performance in human subjects has received considerable interest in cognitive neuroscience because it can provide detailed insights into the neural mechanisms underlying higher-order cognitive control. Despite many decades of research, our understanding of the neurobiological basis of dual-task performance is still limited, and some critical questions are still under debate. Recently, behavioral and neurophysiological studies of dual-task performance in animals have begun to provide intriguing evidence regarding how dual-task information is processed in the brain. In this review, we first summarize key evidence in neuroimaging and neuropsychological studies in humans and discuss possible reasons for discrepancies across studies. We then provide a comprehensive review of the literature on dual-task studies in animals and provide a novel working hypothesis that may reconcile the divergent results in human studies toward a unified view of the mechanisms underlying dual-task processing. Finally, we propose possible directions for future dual-task experiments in the framework of comparative cognitive neuroscience. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  14. Lexicons, contexts, events, and images: commentary on Elman (2009) from the perspective of dual coding theory.

    PubMed

    Paivio, Allan; Sadoski, Mark

    2011-01-01

    Elman (2009) proposed that the traditional role of the mental lexicon in language processing can largely be replaced by a theoretical model of schematic event knowledge founded on dynamic context-dependent variables. We evaluate Elman's approach and propose an alternative view, based on dual coding theory and evidence that modality-specific cognitive representations contribute strongly to word meaning and language performance across diverse contexts which also have effects predictable from dual coding theory. Copyright © 2010 Cognitive Science Society, Inc.

  15. Aerosol climate time series from ESA Aerosol_cci (Invited)

    NASA Astrophysics Data System (ADS)

    Holzer-Popp, T.

    2013-12-01

    Within the ESA Climate Change Initiative (CCI) the Aerosol_cci project (mid 2010 - mid 2013, phase 2 proposed 2014-2016) has conducted intensive work to improve algorithms for the retrieval of aerosol information from European sensors AATSR (3 algorithms), PARASOL, MERIS (3 algorithms), synergetic AATSR/SCIAMACHY, OMI and GOMOS. Whereas OMI and GOMOS were used to derive absorbing aerosol index and stratospheric extinction profiles, respectively, Aerosol Optical Depth (AOD) and Angstrom coefficient were retrieved from the other sensors. Global datasets for 2008 were produced and validated versus independent ground-based data and other satellite data sets (MODIS, MISR). An additional 17-year dataset is currently generated using ATSR-2/AATSR data. During the three years of the project, intensive collaborative efforts were made to improve the retrieval algorithms focusing on the most critical modules. The team agreed on the use of a common definition for the aerosol optical properties. Cloud masking was evaluated, but a rigorous analysis with a pre-scribed cloud mask did not lead to improvement for all algorithms. Better results were obtained using a post-processing step in which sudden transitions, indicative of possible occurrence of cloud contamination, were removed. Surface parameterization, which is most critical for the nadir only algorithms (MERIS and synergetic AATSR / SCIAMACHY) was studied to a limited extent. The retrieval results for AOD, Ångström exponent (AE) and uncertainties were evaluated by comparison with data from AERONET (and a limited amount of MAN) sun photometer and with satellite data available from MODIS and MISR. Both level2 and level3 (gridded daily) datasets were validated. Several validation metrics were used (standard statistical quantities such as bias, rmse, Pearson correlation, linear regression, as well as scoring approaches to quantitatively evaluate the spatial and temporal correlations against AERONET), and in some cases

  16. Dual-Modality Small Animal Imaging System*

    NASA Astrophysics Data System (ADS)

    Ranck, Amoreena; Feldmann, John; Saunders, Robert S.; Welsh, Robert E.; Bradley, Eric L.; Saha, Margaret S.; Kross, Brian; Majewski, Stan; Popov, Vladimir; Weisenberger, Andrew G.; Wojcik, Randolph

    2000-10-01

    We describe preliminary results from an imaging system consisting of an array of position-sensitive photomultiplier tubes (PSPMTs) viewing pixelated scintillators and a small fluoroscopic x-ray system (Lixi, Inc.). The PSPMT detectors are used to follow the uptake of lignads tagged principally with ^125I which emits photons in the 30keV region. The fluoroscope allows the superposition of structural information on the pattern of the radioligands. This "dual modality" technique permits more accurate tracking of the tagged material in the animal under study. Small sources give fiducial information on both x-ray and radioligand pictures allowing close registration of the two views of the system under study. Improvements to this system incorporating a very versatile rotatable gantry capable of supporting a wide range of detection systems simultaneously will be described. *Supported in part by The American Diabetes Association, The Jeffress Trust, The National Science Foundation, The Department of Energy, and The Howard Hughes Foundation

  17. Dual-polarization airborne lidar for freshwater fisheries management and research

    NASA Astrophysics Data System (ADS)

    Roddewig, Michael R.; Pust, Nathan J.; Churnside, James H.; Shaw, Joseph A.

    2017-03-01

    The design of a compact, dual-polarization, nonscanning lidar system intended to fly in a small, single-engine aircraft for airborne study of freshwater marine ecosystems and mapping of fish schools in mountain lakes is discussed. Design trade-offs are presented with special attention paid to selecting the field of view and telescope aperture diameter. Example results and a comparison with a similar existing lidar system are presented.

  18. Color Infrared view of Houston, TX, USA

    NASA Image and Video Library

    1991-09-18

    This color infrared view of Houston (29.5N, 95.0W) was taken with a dual camera mount. Compare this scene with STS048-78-034 for an analysis of the unique properties of each film type. Comparative tests such as this aids in determining the kinds of information unique to each film system and evaluates and compares photography taken through hazy atmospheres. Infrared film is best at penetrating haze, vegetation detection and producing a sharp image.

  19. In-Flight performance of MESSENGER's Mercury dual imaging system

    USGS Publications Warehouse

    Hawkins, S.E.; Murchie, S.L.; Becker, K.J.; Selby, C.M.; Turner, F.S.; Noble, M.W.; Chabot, N.L.; Choo, T.H.; Darlington, E.H.; Denevi, B.W.; Domingue, D.L.; Ernst, C.M.; Holsclaw, G.M.; Laslo, N.R.; Mcclintock, W.E.; Prockter, L.M.; Robinson, M.S.; Solomon, S.C.; Sterner, R.E.

    2009-01-01

    The Mercury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft, launched in August 2004 and planned for insertion into orbit around Mercury in 2011, has already completed two flybys of the innermost planet. The Mercury Dual Imaging System (MDIS) acquired nearly 2500 images from the first two flybys and viewed portions of Mercury's surface not viewed by Mariner 10 in 1974-1975. Mercury's proximity to the Sun and its slow rotation present challenges to the thermal design for a camera on an orbital mission around Mercury. In addition, strict limitations on spacecraft pointing and the highly elliptical orbit create challenges in attaining coverage at desired geometries and relatively uniform spatial resolution. The instrument designed to meet these challenges consists of dual imagers, a monochrome narrow-angle camera (NAC) with a 1.5?? field of view (FOV) and a multispectral wide-angle camera (WAC) with a 10.5?? FOV, co-aligned on a pivoting platform. The focal-plane electronics of each camera are identical and use a 1024??1024 charge-coupled device detector. The cameras are passively cooled but use diode heat pipes and phase-change-material thermal reservoirs to maintain the thermal configuration during the hot portions of the orbit. Here we present an overview of the instrument design and how the design meets its technical challenges. We also review results from the first two flybys, discuss the quality of MDIS data from the initial periods of data acquisition and how that compares with requirements, and summarize how in-flight tests are being used to improve the quality of the instrument calibration. ?? 2009 SPIE.

  20. Dual Protection and Dual Methods in Women Living with HIV: The Brazilian Context

    PubMed Central

    Barbosa, Regina María; Pinho, Adriana de Araujo

    2013-01-01

    The cooccurrence of HIV and unintended pregnancy has prompted a body of work on dual protection, the simultaneous protection against HIV and unintended pregnancy. This study examines dual protection and dual methods as a risk-reduction strategy for women living with HIV. Data are from a cross-sectional sample of HIV-positive women attended in Specialized STI/AIDS Public Health Service Clinics in 13 municipalities from all five regions of Brazil 2003-2004 (N = 834). Descriptive techniques and logistic regression were used to examine dual protection among women living with HIV. We expand the definition of dual protection to include consistent condom use and reversible/irreversible contraceptive methods, we test the dual methods hypothesis that women who use dual methods will use condoms less consistently than women who use only condoms, and we identify predictors of dual protection. Dual protection is common in our sample. Women who use dual methods have lower odds of consistent condom use than women who only use condoms. Among dual method users, we find that women who use an irreversible method use condoms more consistently than women who use a reversible method. Women on ART and with an HIV-serodiscordant partner have greater odds of consistent condom use than their counterparts. PMID:26316959

  1. Potassium-Based Dual Ion Battery with Dual-Graphite Electrode.

    PubMed

    Fan, Ling; Liu, Qian; Chen, Suhua; Lin, Kairui; Xu, Zhi; Lu, Bingan

    2017-08-01

    A potassium ion battery has potential applications for large scale electric energy storage systems due to the abundance and low cost of potassium resources. Dual graphite batteries, with graphite as both anode and cathode, eliminate the use of transition metal compounds and greatly lower the overall cost. Herein, combining the merits of the potassium ion battery and dual graphite battery, a potassium-based dual ion battery with dual-graphite electrode is developed. It delivers a reversible capacity of 62 mA h g -1 and medium discharge voltage of ≈3.96 V. The intercalation/deintercalation mechanism of K + and PF 6 - into/from graphite is proposed and discussed in detail, with various characterizations to support. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Low-cost soft-copy display accuracy in the detection of pulmonary nodules by single-exposure dual-energy subtraction: comparison with hard-copy viewing.

    PubMed

    Kido, S; Kuriyama, K; Hosomi, N; Inoue, E; Kuroda, C; Horai, T

    2000-02-01

    This study endeavored to clarify the usefulness of single-exposure dual-energy subtraction computed radiography (CR) of the chest and the ability of soft-copy images to detect low-contrast simulated pulmonary nodules. Conventional and bone-subtracted CR images of 25 chest phantom image sets with a low-contrast nylon nodule and 25 without a nodule were interpreted by 12 observers (6 radiologists, 6 chest physicians) who rated each on a continuous confidence scale and marked the position of the nodule if one was present. Hard-copy images were 7 x 7-inch laser-printed CR films, and soft-copy images were displayed on a 21-inch noninterlaced color CRT monitor with an optimized dynamic range. Soft-copy images were adjusted to the same size as hard-copy images and were viewed under darkened illumination in the reading room. No significant differences were found between hard- and soft-copy images. In conclusion, the soft-copy images were found to be useful in detecting low-contrast simulated pulmonary nodules.

  3. Optical design and athermalization analysis of infrared dual band refractive-diffractive telephoto objective

    NASA Astrophysics Data System (ADS)

    Dong, Jianing; Zhang, Yinchao; Chen, Siying; Chen, He; Guo, Pan

    2017-02-01

    In order to improve the remote target detection ability of infrared (IR) images effectively, an infrared telephoto objective for 3μm 5μm and 8μm 12μm dual wave-band is designed for 640 pixel×512 pixel infrared CCD detector. The effects of the surrounding environmental temperature are analyzed and the refractive diffractive hybrid thermal compensation is discussed. The focal length of the system is 200mm, the relative aperture is 1:2.2 and the field of view is 7°. The infrared dual band telephoto system with small volume and compact structure is designed in a large range of temperature. The system is composed of four lenses with only three materials of zinc sulfide, zinc selenide and germanium to compensate for the temperature. The image quality of the system is evaluated by ZEMAX optical design software. The results show that the modulation transfer function (MTF) for each field of view at cut-off frequency of 17 lp/mm are respectively greater than 0.6 and 0.4 which approaches the diffraction limit. The telephoto objective has favorable performance at the working temperature of -40°C +60°C. The relative aperture, field of view, and focal length are same for both spectral regions. The system meets the requirements of technical specification.

  4. Silicon Metasurfaces for Integrated Dual Polarized 1.9 THz Heterodyne Array Instruments

    NASA Astrophysics Data System (ADS)

    Alonso-delPino, Maria

    We propose the use of dielectric metasurfaces as the enabling technology to develop a dual polarized heterodyne receiver array with full mapping of the field of view at 1.9 THz. Current heterodyne and non-heterodyne arrays at 1.9 THz are restricted to have sparse mapping in the field of view due to the minimum physical inter-element spacing required between the pixels. Moreover, an integrated dual polarized heterodyne receiver is very difficult to achieve with current technologies at 1.9 THz. We propose the use of metasurfaces that will split the 1.9 THz radiation into two linear polarizations and focus them both on the same receiver plane. Additionally, by overlapping common regions of the metasurface we will have a full mapping of the field of view, i.e. the beams will be highly overlapped in the field of sky observation which is not the case with current generation of array instruments. The metasurface consists of a dielectric planar structure with subwavelength 3D features that controls the amplitude and phase of the electric field that goes through them. These structures are usually used in reflection in the microwave frequency range and has not been used at terahertz frequencies before. We propose the development of these metasurfaces in transmission and integrate them into a multi-pixel heterodyne receiver at 1.9 THz. The silicon micro-machining process developed at JPL allows the fabrication of high aspect ratio multi-depth features on silicon wafers and will allow the integration of both, receiver and metasurfaces, in the same wafer stack. It will lead to a more compact, low-mass, and low loss dual polarized multi-pixel receiver with efficient illumination at 1.9 THz. Even though this work will target the 1.8-2.1 THz band for the CII and OI lines, these designs can be easily scaled to at least 5 THz.

  5. Dual Diagnosis - Multiple Languages

    MedlinePlus

    ... National Library of Medicine Comorbidity or dual diagnosis - Opioid addiction, part 9 - English PDF Comorbidity or dual diagnosis - Opioid addiction, part 9 - español (Spanish) PDF Comorbidity or dual ...

  6. Lesion Quantification in Dual-Modality Mammotomography

    NASA Astrophysics Data System (ADS)

    Li, Heng; Zheng, Yibin; More, Mitali J.; Goodale, Patricia J.; Williams, Mark B.

    2007-02-01

    This paper describes a novel x-ray/SPECT dual modality breast imaging system that provides 3D structural and functional information. While only a limited number of views on one side of the breast can be acquired due to mechanical and time constraints, we developed a technique to compensate for the limited angle artifact in reconstruction images and accurately estimate both the lesion size and radioactivity concentration. Various angular sampling strategies were evaluated using both simulated and experimental data. It was demonstrated that quantification of lesion size to an accuracy of 10% and quantification of radioactivity to an accuracy of 20% are feasible from limited-angle data acquired with clinically practical dosage and acquisition time

  7. Efficient material decomposition method for dual-energy X-ray cargo inspection system

    NASA Astrophysics Data System (ADS)

    Lee, Donghyeon; Lee, Jiseoc; Min, Jonghwan; Lee, Byungcheol; Lee, Byeongno; Oh, Kyungmin; Kim, Jaehyun; Cho, Seungryong

    2018-03-01

    Dual-energy X-ray inspection systems are widely used today for it provides X-ray attenuation contrast of the imaged object and also its material information. Material decomposition capability allows a higher detection sensitivity of potential targets including purposely loaded impurities in agricultural product inspections and threats in security scans for example. Dual-energy X-ray transmission data can be transformed into two basis material thickness data, and its transformation accuracy heavily relies on a calibration of material decomposition process. The calibration process in general can be laborious and time consuming. Moreover, a conventional calibration method is often challenged by the nonuniform spectral characteristics of the X-ray beam in the entire field-of-view (FOV). In this work, we developed an efficient material decomposition calibration process for a linear accelerator (LINAC) based high-energy X-ray cargo inspection system. We also proposed a multi-spot calibration method to improve the decomposition performance throughout the entire FOV. Experimental validation of the proposed method has been demonstrated by use of a cargo inspection system that supports 6 MV and 9 MV dual-energy imaging.

  8. For soldier and state: dual loyalty and World War One.

    PubMed

    van Bergen, Leo

    2012-01-01

    Military medicine has always been characterized by some form of dual loyalty: physicians have to consider the interests of the individual soldier--patient as well as the interests of the state and the military in general. The way in which each individual doctor responds to this dual loyalty has mostly been viewed as a product of war circumstances on the one hand, and the personal character and/or religious and ideological beliefs of the physician on the other. Taking World War One as an example, this article argues that the nature of the illness or wound also had a part to play in this. The article shows that the disfigured were looked upon mainly in relation to the patient's own interests; the invalided-out through a combination of the patient's as well as the state's interests; and the neurotic mainly out of concern for the interests of the state.

  9. PRIMA: study for a dual-beam instrument for the VLT Interferometer

    NASA Astrophysics Data System (ADS)

    Quirrenbach, Andreas; Coudé du Foresto, Vincent; Daigne, Gerard; Hofmann, Karl H.; Hofmann, Reiner; Lattanzi, Mario; Osterbart, R.; Le Poole, Rudolf S.; Queloz, Didier; Vakili, Farrokh

    1998-07-01

    PRIMA is a conceptual study for a single-baseline dual-feed instrument for the very large telescope interferometer, which is under construction by the European Southern Observatory on Cerro Paranal in Chile. The goals of PRIMA include narrow-angle astrometry with a precision of 10 (mu) as over an arc of 10 inches, and imaging of faint sources with the full sensitivity of the 8m telescopes in the VLT array. Key scientific programs that can be carried out with PRIMA in imaging mode include observations of active galactic nuclei, the Galactic Center, stars, and circumstellar matter. Scientific drivers for the astrometry are searches for planets and low-mass stellar companions, binary stars, dynamics of clusters, and parallaxes. We list the main performance requirements for PRIMA, present system architectures for the dual-beam system, and discuss limitations of the interferometric field-of-view.

  10. Caustic Singularities Of High-Gain, Dual-Shaped Reflectors

    NASA Technical Reports Server (NTRS)

    Galindo, Victor; Veruttipong, Thavath W.; Imbriale, William A.; Rengarajan, Sambiam

    1991-01-01

    Report presents study of some sources of error in analysis, by geometric theory of diffraction (GTD), of performance of high-gain, dual-shaped antenna reflector. Study probes into underlying analytic causes of singularity, with view toward devising and testing practical methods to avoid problems caused by singularity. Hybrid physical optics (PO) approach used to study near-field spillover or noise-temperature characteristics of high-gain relector antenna efficiently and accurately. Report illustrates this approach and underlying principles by presenting numerical results, for both offset and symmetrical reflector systems, computed by GTD, PO, and PO/GO methods.

  11. Familiarity Breeds Attempts: A Critical Review of Dual-Process Theories of Recognition.

    PubMed

    Mandler, George

    2008-09-01

    Recognition memory and recall/recollection are the major divisions of the psychology of human memory. Theories of recognition have shifted from a "strength" approach to a dual-process view, which distinguishes between knowing that one has experienced an object before and knowing what it was. In this article, I discuss the history of this approach and the two processes of familiarity and recollection and locate their origin in pattern matching and organization. I evaluate various theories in terms of their basic requirements and their defining research and propose the extension of the original two process theory to domains such as pictorial recognition. Finally, I present the main phenomena that a dual-process theory of recognition must account for and discuss future needs and directions of research and development. © 2008 Association for Psychological Science.

  12. Toward a Unified Military Response: Hurricane Sandy and the Dual Status Commander

    DTIC Science & Technology

    2015-04-01

    and support by developing self -awareness through leader feedback and leader resiliency. The School of Strategic Landpower develops strategic...forces; • Regional strategic appraisals; • The nature of land warfare; • Matters affecting the Army’s future; • The concepts, philosophy, and theory of...Army War College Press TOWARD A UNIFIED MILITARY RESPONSE: HURRICANE SANDY AND THE DUAL STATUS COMMANDER Ryan Burke Sue McNeil April 2015 The views

  13. For Whom Is a Picture Worth a Thousand Words? Extensions of a Dual-Coding Theory of Multimedia Learning.

    ERIC Educational Resources Information Center

    Mayer, Richard E.; Sims, Valerie K.

    1994-01-01

    In 2 experiments, 162 high- and low-spatial ability students viewed a computer-generated animation and heard a concurrent or successive explanation. The concurrent group generated more creative solutions to transfer problems and demonstrated a contiguity effect consistent with dual-coding theory. (SLD)

  14. Nonlinear analysis for dual-frequency concurrent energy harvesting

    NASA Astrophysics Data System (ADS)

    Yan, Zhimiao; Lei, Hong; Tan, Ting; Sun, Weipeng; Huang, Wenhu

    2018-05-01

    The dual-frequency responses of the hybrid energy harvester undergoing the base excitation and galloping were analyzed numerically. In this work, an approximate dual-frequency analytical method is proposed for the nonlinear analysis of such a system. To obtain the approximate analytical solutions of the full coupled distributed-parameter model, the forcing interactions is first neglected. Then, the electromechanical decoupled governing equation is developed using the equivalent structure method. The hybrid mechanical response is finally separated to be the self-excited and forced responses for deriving the analytical solutions, which are confirmed by the numerical simulations of the full coupled model. The forced response has great impacts on the self-excited response. The boundary of Hopf bifurcation is analytically determined by the onset wind speed to galloping, which is linearly increased by the electrical damping. Quenching phenomenon appears when the increasing base excitation suppresses the galloping. The theoretical quenching boundary depends on the forced mode velocity. The quenching region increases with the base acceleration and electrical damping, but decreases with the wind speed. Superior to the base-excitation-alone case, the existence of the aerodynamic force protects the hybrid energy harvester at resonance from damages caused by the excessive large displacement. From the view of the harvested power, the hybrid system surpasses the base-excitation-alone system or the galloping-alone system. This study advances our knowledge on intrinsic nonlinear dynamics of the dual-frequency energy harvesting system by taking advantage of the analytical solutions.

  15. Close up view of the center console on the flight ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Close up view of the center console on the flight deck of the Orbiter Discovery showing the console's instrumentation and controls. The commanders station is located to the left in this view and the pilot's station is to the right in the view. The handle and lever located on the right side of the center console and towards its front is one of a pair, the commander has one on the left of his seat in his station, of Speed Brake/Thrust Controllers. These are dual purpose controllers. During ascent the controller can be use to throttle the main engines and during entry the controllers can be used to control aerodynamic drag by opening or closing the orbiter's speed brake. - Space Transportation System, Orbiter Discovery (OV-103), Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

  16. Predicted accommodative response from image quality in young eyes fitted with different dual-focus designs.

    PubMed

    Faria-Ribeiro, Miguel; Amorim-de-Sousa, Ana; González-Méijome, José M

    2018-05-01

    To investigate the separated and combined influences of inner zone (IZ) diameter and effective add power of dual-focus contact lenses (CL) in the image quality at distance and near viewing, in a functional accommodating model eye. Computational wave-optics methods were used to define zonal bifocal pupil functions, representing the optic zones of nine dual-focus centre-distance CLs. The dual-focus pupil functions were defined having IZ diameters of 2.10 mm, 3.36 mm and 4.00 mm, with add powers of 1.5 D, 2.0 D and 2.5 D (dioptres), for each design, that resulted in a ratio of 64%/36% between the distance and treatment zone areas, bounded by a 6 mm entrance pupil. A through-focus routine was implemented in MATLAB to simulate the changes in image quality, calculated from the Visual Strehl ratio, as the eye with the dual-focus accommodates, from 0 to -3.00 D target vergences. Accommodative responses were defined as the changes in the defocus coefficient, combined with a change in fourth and sixth order spherical aberration, which produced a peak in image quality at each target vergence. Distance viewing image quality was marginally affected by IZ diameter but not by add power. Near image quality obtained when focussing the image formed by the near optics was only higher by a small amount compared to the other two IZ diameters. The mean ± standard deviation values obtained with the three adds were 0.28 ± 0.02, 0.23 ± 0.02 and 0.22 ± 0.02, for the small, medium and larger IZ diameters, respectively. On the other hand, near image quality predicted by focussing the image formed by the distance optics was considerably lower relatively to the other two IZ diameters. The mean ± standard deviation values obtained with the three adds were 0.15 ± 0.01, 0.38 ± 0.00 and 0.54 ± 0.01, for the small, medium and larger IZ diameters, respectively. During near viewing through dual-focus CLs, image quality depends on the diameter of the most inner zone of the CL, while add power

  17. 44. Building 102, view from mezzanine looking down to first ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    44. Building 102, view from mezzanine looking down to first floor showing Klystron tube equipment vaults with dual waveguides leaving top of vaults through bifurcation combiner system at start of waveguides; note tops of capacitor vaults along photograph to left. - Clear Air Force Station, Ballistic Missile Early Warning System Site II, One mile west of mile marker 293.5 on Parks Highway, 5 miles southwest of Anderson, Anderson, Denali Borough, AK

  18. Development of a Dual-PIV system for high-speed flow applications

    NASA Astrophysics Data System (ADS)

    Schreyer, Anne-Marie; Lasserre, Jean J.; Dupont, Pierre

    2015-10-01

    A new Dual-particle image velocimetry (Dual-PIV) system for application in supersonic flows was developed. The system was designed for shock wave/turbulent boundary layer interactions with separation. This type of flow places demanding requirements on the system, from the large range of characteristic frequencies O(100 Hz-100 kHz) to spatial and temporal resolutions necessary for the measurement of turbulent quantities (Dolling in AIAA J 39(8):1517-1531, 2001; Dupont et al. in J Fluid Mech 559:255-277, 2006; Smits and Dussauge in Turbulent shear layers in supersonic flow, 2nd edn. Springer, New York, 2006). While classic PIV systems using high-resolution CCD sensors allow high spatial resolution, these systems cannot provide the required temporal resolution. Existing high-speed PIV systems provide temporal and CMOS sensor resolutions, and even laser pulse energies, that are not adapted to our needs. The only obvious solution allowing sufficiently high spatial resolution, access to high frequencies, and a high laser pulse energy is a multi-frame system: a Dual-PIV system, consisting of two synchronized PIV systems observing the same field of view, will give access to temporal characteristics of the flow. The key technology of our system is frequency-based image separation: two lasers of different wavelengths illuminate the field of view. The cross-pollution with laser light from the respective other branches was quantified during system validation. The overall system noise was quantified, and the prevailing error of only 2 % reflects the good spatial and temporal alignment. The quality of the measurement system is demonstrated with some results on a subsonic jet flow including the spatio-temporal inter-correlation functions between the systems. First measurements in a turbulent flat-plate boundary layer at Mach 2 show the same satisfactory data quality and are also presented and discussed.

  19. Dual peer mentoring program for undergraduate medical students: exploring the perceptions of mentors and mentees

    PubMed Central

    Abdolalizadeh, Parya; Pourhassan, Saeed; Gandomkar, Roghayeh; Heidari, Farrokh; Sohrabpour, Amir Ali

    2017-01-01

    Background: Despite the advantages of dual peer mentoring, there are a few reports of implementing and evaluating such programs for medical students. This study aimed at exploring the perceptions of mentors and mentees about the dual peer mentoring program for the first year undergraduate medical students of Tehran University of Medical Sciences. Methods: This qualitative study was conducted at the end of the first year of implementing the mentoring program. All mentees and mentors were invited to participate in focus group discussions. Data were analyzed using a qualitative content analysis. Results: All mentors (n= 12) and a group of mentees (n= 21) participated in focus group discussion sessions. We provided a variety of supports for the mentees including academic and psychosocial support and positive relationship; as a result, some developments occurred to the mentors We also explored participants’ views on some unique aspects of the program such as student-authorized, dual mentoring, and role model sessions. Conclusion: Our participants found the mentoring program beneficial in various academic achievements and psychosocial supports for both the mentors and the mentees. Dual peer mentoring program can be an alternative to school administered programs. PMID:28638809

  20. Dual peer mentoring program for undergraduate medical students: exploring the perceptions of mentors and mentees.

    PubMed

    Abdolalizadeh, Parya; Pourhassan, Saeed; Gandomkar, Roghayeh; Heidari, Farrokh; Sohrabpour, Amir Ali

    2017-01-01

    Background: Despite the advantages of dual peer mentoring, there are a few reports of implementing and evaluating such programs for medical students. This study aimed at exploring the perceptions of mentors and mentees about the dual peer mentoring program for the first year undergraduate medical students of Tehran University of Medical Sciences. Methods: This qualitative study was conducted at the end of the first year of implementing the mentoring program. All mentees and mentors were invited to participate in focus group discussions. Data were analyzed using a qualitative content analysis. Results: All mentors ( n= 12 ) and a group of mentees ( n= 21 ) participated in focus group discussion sessions. We provided a variety of supports for the mentees including academic and psychosocial support and positive relationship; as a result, some developments occurred to the mentors We also explored participants' views on some unique aspects of the program such as student-authorized, dual mentoring, and role model sessions. Conclusion: Our participants found the mentoring program beneficial in various academic achievements and psychosocial supports for both the mentors and the mentees. Dual peer mentoring program can be an alternative to school administered programs.

  1. A LabVIEW Platform for Preclinical Imaging Using Digital Subtraction Angiography and Micro-CT.

    PubMed

    Badea, Cristian T; Hedlund, Laurence W; Johnson, G Allan

    2013-01-01

    CT and digital subtraction angiography (DSA) are ubiquitous in the clinic. Their preclinical equivalents are valuable imaging methods for studying disease models and treatment. We have developed a dual source/detector X-ray imaging system that we have used for both micro-CT and DSA studies in rodents. The control of such a complex imaging system requires substantial software development for which we use the graphical language LabVIEW (National Instruments, Austin, TX, USA). This paper focuses on a LabVIEW platform that we have developed to enable anatomical and functional imaging with micro-CT and DSA. Our LabVIEW applications integrate and control all the elements of our system including a dual source/detector X-ray system, a mechanical ventilator, a physiological monitor, and a power microinjector for the vascular delivery of X-ray contrast agents. Various applications allow cardiac- and respiratory-gated acquisitions for both DSA and micro-CT studies. Our results illustrate the application of DSA for cardiopulmonary studies and vascular imaging of the liver and coronary arteries. We also show how DSA can be used for functional imaging of the kidney. Finally, the power of 4D micro-CT imaging using both prospective and retrospective gating is shown for cardiac imaging.

  2. A LabVIEW Platform for Preclinical Imaging Using Digital Subtraction Angiography and Micro-CT

    PubMed Central

    Badea, Cristian T.; Hedlund, Laurence W.; Johnson, G. Allan

    2013-01-01

    CT and digital subtraction angiography (DSA) are ubiquitous in the clinic. Their preclinical equivalents are valuable imaging methods for studying disease models and treatment. We have developed a dual source/detector X-ray imaging system that we have used for both micro-CT and DSA studies in rodents. The control of such a complex imaging system requires substantial software development for which we use the graphical language LabVIEW (National Instruments, Austin, TX, USA). This paper focuses on a LabVIEW platform that we have developed to enable anatomical and functional imaging with micro-CT and DSA. Our LabVIEW applications integrate and control all the elements of our system including a dual source/detector X-ray system, a mechanical ventilator, a physiological monitor, and a power microinjector for the vascular delivery of X-ray contrast agents. Various applications allow cardiac- and respiratory-gated acquisitions for both DSA and micro-CT studies. Our results illustrate the application of DSA for cardiopulmonary studies and vascular imaging of the liver and coronary arteries. We also show how DSA can be used for functional imaging of the kidney. Finally, the power of 4D micro-CT imaging using both prospective and retrospective gating is shown for cardiac imaging. PMID:27006920

  3. Dual-targeting siRNAs

    PubMed Central

    Tiemann, Katrin; Höhn, Britta; Ehsani, Ali; Forman, Stephen J.; Rossi, John J.; Sætrom, Pål

    2010-01-01

    We have developed an algorithm for the prediction of dual-targeting short interfering RNAs (siRNAs) in which both strands are deliberately designed to separately target different mRNA transcripts with complete complementarity. An advantage of this approach versus the use of two separate duplexes is that only two strands, as opposed to four, are competing for entry into the RNA-induced silencing complex. We chose to design our dual-targeting siRNAs as Dicer substrate 25/27mer siRNAs, since design features resembling pre-microRNAs (miRNAs) can be introduced for Dicer processing. Seven different dual-targeting siRNAs targeting genes that are potential targets in cancer therapy have been developed including Bcl2, Stat3, CCND1, BIRC5, and MYC. The dual-targeting siRNAs have been characterized for dual target knockdown in three different cell lines (HEK293, HCT116, and PC3), where they were as effective as their corresponding single-targeting siRNAs in target knockdown. The algorithm developed in this study should prove to be useful for predicting dual-targeting siRNAs in a variety of different targets and is available from http://demo1.interagon.com/DualTargeting/. PMID:20410240

  4. Dual LED/incandescent security fixture

    DOEpatents

    Gauna, Kevin Wayne

    2005-06-21

    A dual LED and incandescent security lighting system uses a hybrid approach to LED illumination. It combines an ambient LED illuminator with a standard incandescent lamp on a motion control sensor. The LED illuminator will activate with the onset of darkness (daylight control) and typically remain on during the course of the night ("always on"). The LED illumination, typically amber, is sufficient to provide low to moderate level lighting coverage to the wall and ground area adjacent to and under the fixture. The incandescent lamp is integrated with a motion control circuit and sensor. When movement in the field of view is detected (after darkness), the incandescent lamp is switched on, providing an increased level of illumination to the area. Instead of an "always on" LED illuminator, the LEDs may also be switched off when the incandescent lamp is switched on.

  5. Lp-dual affine surface area

    NASA Astrophysics Data System (ADS)

    Wei, Wang; Binwu, He

    2008-12-01

    According to the notion of Lp-affine surface area by Lutwak, in this paper, we introduce the concept of Lp-dual affine surface area. Further, we establish the affine isoperimetric inequality and the Blaschke-Santaló inequality for Lp-dual affine surface area. Besides, the dual Brunn-Minkowski inequality for Lp-dual affine surface area is presented.

  6. A graphics approach in the design of the dual air density Explorer satellites

    NASA Technical Reports Server (NTRS)

    Mcdougal, D. S.

    1975-01-01

    A computer program was developed to generate a graphics display of the Dual Air Density (DAD) Explorer satellites which aids in the engineering and scientific design. The program displays a two-dimensional view of both spacecraft and their surface features from any direction. The graphics have been an indispensable tool in the design, analysis, and understanding of the critical locations of the various surface features for both satellites.

  7. Dual-energy contrast enhanced digital breast tomosynthesis: concept, method, and evaluation on phantoms

    NASA Astrophysics Data System (ADS)

    Puong, Sylvie; Patoureaux, Fanny; Iordache, Razvan; Bouchevreau, Xavier; Muller, Serge

    2007-03-01

    In this paper, we present the development of dual-energy Contrast-Enhanced Digital Breast Tomosynthesis (CEDBT). A method to produce background clutter-free slices from a set of low and high-energy projections is introduced, along with a scheme for the determination of the optimal low and high-energy techniques. Our approach consists of a dual-energy recombination of the projections, with an algorithm that has proven its performance in Contrast-Enhanced Digital Mammography1 (CEDM), followed by an iterative volume reconstruction. The aim is to eliminate the anatomical background clutter and to reconstruct slices where the gray level is proportional to the local iodine volumetric concentration. Optimization of the low and high-energy techniques is performed by minimizing the total glandular dose to reach a target iodine Signal Difference to Noise Ratio (SDNR) in the slices. In this study, we proved that this optimization could be done on the projections, by consideration of the SDNR in the projections instead of the SDNR in the slices, and verified this with phantom measurements. We also discuss some limitations of dual-energy CEDBT, due to the restricted angular range for the projection views, and to the presence of scattered radiation. Experiments on textured phantoms with iodine inserts were conducted to assess the performance of dual-energy CEDBT. Texture contrast was nearly completely removed and the iodine signal was enhanced in the slices.

  8. Dual Motor-Cognitive Virtual Reality Training Impacts Dual-Task Performance in Freezing of Gait.

    PubMed

    Killane, Isabelle; Fearon, Conor; Newman, Louise; McDonnell, Conor; Waechter, Saskia M; Sons, Kristian; Lynch, Timothy; Reilly, Richard B

    2015-11-01

    Freezing of gait (FOG), an episodic gait disturbance characterized by the inability to generate effective stepping, occurs in more than half of Parkinson's disease patients. It is associated with both executive dysfunction and attention and becomes most evident during dual tasking (performing two tasks simultaneously). This study examined the effect of dual motor-cognitive virtual reality training on dual-task performance in FOG. Twenty community dwelling participants with Parkinson's disease (13 with FOG, 7 without FOG) participated in a pre-assessment, eight 20-minute intervention sessions, and a post-assessment. The intervention consisted of a virtual reality maze (DFKI, Germany) through which participants navigated by stepping-in-place on a balance board (Nintendo, Japan) under time pressure. This was combined with a cognitive task (Stroop test), which repeatedly divided participants' attention. The primary outcome measures were pre- and post-intervention differences in motor (stepping time, symmetry, rhythmicity) and cognitive (accuracy, reaction time) performance during single- and dual-tasks. Both assessments consisted of 1) a single cognitive task 2) a single motor task, and 3) a dual motor-cognitive task. Following the intervention, there was significant improvement in dual-task cognitive and motor parameters (stepping time and rhythmicity), dual-task effect for those with FOG and a noteworthy improvement in FOG episodes. These improvements were less significant for those without FOG. This is the first study to show benefit of a dual motor-cognitive approach on dual-task performance in FOG. Advances in such virtual reality interventions for home use could substantially improve the quality of life for patients who experience FOG.

  9. The Effect of Dual-Language Immersion on Student Achievement in Math, Science, and English Language Arts

    ERIC Educational Resources Information Center

    Steele, Jennifer L.; Slater, Robert; Li, Jennifer; Zamarro, Gema; Miller, Trey

    2013-01-01

    Confronted with many challenges to improving the quality of U.S. public K-12 education, many policymakers have viewed the study of a second language as a useful but nonessential ingredient of a world-class education system. However, others point out that dual-language education can be a powerful intervention for closing the achievement gap for…

  10. Discrimination of face gender and expression under dual-task conditions.

    PubMed

    García-Gutiérrez, Ana; Aguado, Luis; Romero-Ferreiro, Verónica; Pérez-Moreno, Elisa

    2017-02-01

    In order to test whether expression and gender can be attended to simultaneously without a cost in accuracy four experiments were carried out using a dual gender-expression task with male and female faces showing different emotional expressions that were backward masked by emotionally neutral faces. In the dual-facial condition the participants had to report both the gender and the expression of the targets. In two control conditions the participant reported either the gender or the expression of the face and indicated whether a surrounding frame was continuous or discontinuous. In Experiments 1-3, with angry and happy targets, asymmetric interference was observed. Gender discrimination, but no expression discrimination, was impaired in the dual-facial condition compared to the corresponding control. This effect was obtained with a between-subjects design in Experiment 1, with a within-subjects design in Experiment 2, and with androgynous face masks in Experiment 3. In Experiments 4a and 4b different target combinations were tested. No decrement of performance in the dual-facial task was observed for either gender or expression discrimination with fearful-disgusted (Experiment 4a) or fearful-happy faces (Experiment 4b). We conclude that the ability to attend simultaneously to gender and expression cues without a decrement in performance depends on the specific combination of expressions to be differentiated between. Happy and angry expressions are usually directed at the perceiver and command preferential attention. Under conditions of restricted viewing such as those of the present study, discrimination of these expressions is prioritized leading to impaired discrimination of other facial properties such as gender.

  11. Analysis of a generalized dual reflector antenna system using physical optics

    NASA Technical Reports Server (NTRS)

    Acosta, Roberto J.; Lagin, Alan R.

    1992-01-01

    Reflector antennas are widely used in communication satellite systems because they provide high gain at low cost. Offset-fed single paraboloids and dual reflector offset Cassegrain and Gregorian antennas with multiple focal region feeds provide a simple, blockage-free means of forming multiple, shaped, and isolated beams with low sidelobes. Such antennas are applicable to communications satellite frequency reuse systems and earth stations requiring access to several satellites. While the single offset paraboloid has been the most extensively used configuration for the satellite multiple-beam antenna, the trend toward large apertures requiring minimum scanned beam degradation over the field of view 18 degrees for full earth coverage from geostationary orbit may lead to impractically long focal length and large feed arrays. Dual reflector antennas offer packaging advantages and more degrees of design freedom to improve beam scanning and cross-polarization properties. The Cassegrain and Gregorian antennas are the most commonly used dual reflector antennas. A computer program for calculating the secondary pattern and directivity of a generalized dual reflector antenna system was developed and implemented at LeRC. The theoretical foundation for this program is based on the use of physical optics methodology for describing the induced currents on the sub-reflector and main reflector. The resulting induced currents on the main reflector are integrated to obtain the antenna far-zone electric fields. The computer program is verified with other physical optics programs and with measured antenna patterns. The comparison shows good agreement in far-field sidelobe reproduction and directivity.

  12. Confocal fluorescence microscope with dual-axis architecture and biaxial postobjective scanning

    PubMed Central

    Wang, Thomas D.; Contag, Christopher H.; Mandella, Michael J.; Chan, Ning Y.; Kino, Gordon S.

    2007-01-01

    We present a novel confocal microscope that has dual-axis architecture and biaxial postobjective scanning for the collection of fluorescence images from biological specimens. This design uses two low-numerical-aperture lenses to achieve high axial resolution and long working distance, and the scanning mirror located distal to the lenses rotates along the orthogonal axes to produce arc-surface images over a large field of view (FOV). With fiber optic coupling, this microscope can potentially be scaled down to millimeter dimensions via microelectromechanical systems (MEMS) technology. We demonstrate a benchtop prototype with a spatial resolution ≤4.4 μm that collects fluorescence images with a high SNR and a good contrast ratio from specimens expressing GFP. Furthermore, the scanning mechanism produces only small differences in aberrations over the image FOV. These results demonstrate proof of concept of the dual-axis confocal architecture for in vivo molecular and cellular imaging. PMID:15250760

  13. Dual leadership in a hospital practice.

    PubMed

    Thude, Bettina Ravnborg; Thomsen, Svend Erik; Stenager, Egon; Hollnagel, Erik

    2017-02-06

    Purpose Despite the practice of dual leadership in many organizations, there is relatively little research on the topic. Dual leadership means two leaders share the leadership task and are held jointly accountable for the results of the unit. To better understand how dual leadership works, this study aims to analyse three different dual leadership pairs at a Danish hospital. Furthermore, this study develops a tool to characterize dual leadership teams from each other. Design/methodology/approach This is a qualitative study using semi-structured interviews. Six leaders were interviewed to clarify how dual leadership works in a hospital context. All interviews were transcribed and coded. During coding, focus was on the nine principles found in the literature and another principle was found by looking at the themes that were generic for all six interviews. Findings Results indicate that power balance, personal relations and decision processes are important factors for creating efficient dual leaderships. The study develops a categorizing tool to use for further research or for organizations, to describe and analyse dual leaderships. Originality/value The study describes dual leadership in the hospital context and develops a categorizing tool for being able to distinguish dual leadership teams from each other. It is important to reveal if there are any indicators that can be used for optimising dual leadership teams in the health-care sector and in other organisations.

  14. Experimental Array for Generating Dual Circularly-Polarized Dual-Mode OAM Radio Beams.

    PubMed

    Bai, Xu-Dong; Liang, Xian-Ling; Sun, Yun-Tao; Hu, Peng-Cheng; Yao, Yu; Wang, Kun; Geng, Jun-Ping; Jin, Rong-Hong

    2017-01-10

    Recently, vortex beam carrying orbital angular momentum (OAM) for radio communications has attracted much attention for its potential of transmitting multiple signals simultaneously at the same frequency, which can be used to increase the channel capacity. However, most of the methods for getting multi-mode OAM radio beams are of complicated structure and very high cost. This paper provides an effective solution of generating dual circularly-polarized (CP) dual-mode OAM beams. The antenna consists of four dual-CP elements which are sequentially rotated 90 degrees in the clockwise direction. Different from all previous published research relating to OAM generation by phased arrays, the four elements are fed with the same phase for both left-hand circular polarization (LHCP) and right-hand circular polarization (RHCP). The dual-mode operation for OAM is achieved through the opposite phase differences generated for LHCP and RHCP, when the dual-CP elements are sequentially rotated in the clockwise direction. The measured results coincide well with the simulated ones, which verified the effectiveness of the proposed design.

  15. Framing U-Net via Deep Convolutional Framelets: Application to Sparse-View CT.

    PubMed

    Han, Yoseob; Ye, Jong Chul

    2018-06-01

    X-ray computed tomography (CT) using sparse projection views is a recent approach to reduce the radiation dose. However, due to the insufficient projection views, an analytic reconstruction approach using the filtered back projection (FBP) produces severe streaking artifacts. Recently, deep learning approaches using large receptive field neural networks such as U-Net have demonstrated impressive performance for sparse-view CT reconstruction. However, theoretical justification is still lacking. Inspired by the recent theory of deep convolutional framelets, the main goal of this paper is, therefore, to reveal the limitation of U-Net and propose new multi-resolution deep learning schemes. In particular, we show that the alternative U-Net variants such as dual frame and tight frame U-Nets satisfy the so-called frame condition which makes them better for effective recovery of high frequency edges in sparse-view CT. Using extensive experiments with real patient data set, we demonstrate that the new network architectures provide better reconstruction performance.

  16. Motivating factors for dual-method contraceptive use among adolescents and young women: a qualitative investigation.

    PubMed

    Lemoine, Julie; Teal, Stephanie B; Peters, Marissa; Guiahi, Maryam

    2017-11-01

    This qualitative study explores how adolescents and young women perceive the need for and describe the use of dual method contraception. We interviewed 20 sexually active women aged 16-24 who attended an adolescent-focused Title X family-planning clinic and were using a non-barrier contraceptive method. We used a semi-structured interview guide that included domains related to sexual activity, knowledge of and use of contraceptives and condoms, and relationship factors. We coded transcripts using grounded theory techniques and used an iterative process to develop overarching themes. Dual method contraceptive users primarily discussed pregnancy prevention as their motivating factor. Many expressed anxieties over an unplanned pregnancy and reported condom use as "back-up" contraception. Risk perception for pregnancy or STI acquisition did not necessarily change as relationship trust increased, but rather, their anxiety regarding the negativity of such outcomes decreased. Dual-method contraception use decreased when participants reported that condoms were not readily available, or when they self-described immaturity. Less frequently, participants reported dual method use for sexually transmitted infection (STI) prevention, and many substituted STI testing for condom use. Contraceptive type (short-acting vs. long-acting) did not influence reported attitudes towards dual method use. Health educators and clinicians encourage condom use in young women due to the significant morbidity associated with STI acquisition. Most participants in our study view condoms as a way to improve pregnancy prevention. Acknowledging and addressing this divergence in motivation will allow caregivers to improve strategies for communicating the importance of dual method use. Young women primarily describe pregnancy prevention as the reason for dual method use, STI protection is less salient. Consideration of this viewpoint by health educators and clinicians will allow us to communicate more

  17. Nonword Reading: Comparing Dual-Route Cascaded and Connectionist Dual-Process Models with Human Data

    ERIC Educational Resources Information Center

    Pritchard, Stephen C.; Coltheart, Max; Palethorpe, Sallyanne; Castles, Anne

    2012-01-01

    Two prominent dual-route computational models of reading aloud are the dual-route cascaded (DRC) model, and the connectionist dual-process plus (CDP+) model. While sharing similarly designed lexical routes, the two models differ greatly in their respective nonlexical route architecture, such that they often differ on nonword pronunciation. Neither…

  18. The Dual Language Program Planner: A Guide for Designing and Implementing Dual Language Programs.

    ERIC Educational Resources Information Center

    Howard, Elizabeth R.; Olague, Natalie; Rogers, David

    This guide offers a framework to facilitate the planning process for dual language programs, assuming at least a basic working knowledge of the central characteristics and essential features of dual language models. It provides an overview of the various models that serve linguistically diverse student populations, defining the term dual language…

  19. Acute effects of alcohol on intrusive memory development and viewpoint dependence in spatial memory support a dual representation model.

    PubMed

    Bisby, James A; King, John A; Brewin, Chris R; Burgess, Neil; Curran, H Valerie

    2010-08-01

    A dual representation model of intrusive memory proposes that personally experienced events give rise to two types of representation: an image-based, egocentric representation based on sensory-perceptual features; and a more abstract, allocentric representation that incorporates spatiotemporal context. The model proposes that intrusions reflect involuntary reactivation of egocentric representations in the absence of a corresponding allocentric representation. We tested the model by investigating the effect of alcohol on intrusive memories and, concurrently, on egocentric and allocentric spatial memory. With a double-blind independent group design participants were administered alcohol (.4 or .8 g/kg) or placebo. A virtual environment was used to present objects and test recognition memory from the same viewpoint as presentation (tapping egocentric memory) or a shifted viewpoint (tapping allocentric memory). Participants were also exposed to a trauma video and required to detail intrusive memories for 7 days, after which explicit memory was assessed. There was a selective impairment of shifted-view recognition after the low dose of alcohol, whereas the high dose induced a global impairment in same-view and shifted-view conditions. Alcohol showed a dose-dependent inverted "U"-shaped effect on intrusions, with only the low dose increasing the number of intrusions, replicating previous work. When same-view recognition was intact, decrements in shifted-view recognition were associated with increases in intrusions. The differential effect of alcohol on intrusive memories and on same/shifted-view recognition support a dual representation model in which intrusions might reflect an imbalance between two types of memory representation. These findings highlight important clinical implications, given alcohol's involvement in real-life trauma. Copyright 2010 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

  20. Differences between Dual Users and Switchers Center around Vaping Behavior and Its Experiences Rather than Beliefs and Attitudes.

    PubMed

    Adriaens, Karolien; Van Gucht, Dinska; Baeyens, Frank

    2017-12-23

    (1) Background: Many smokers completely switch to vaping (switchers), whereas others use e-cigarettes (e-cigs) alongside tobacco cigarettes (dual users). To the extent that dual users substantially lower the number of cigarettes, they will reduce health risks from smoking. However, from a medical point of view, exclusive vaping is preferable to dual use; (2) Methods: Using an online questionnaire we assessed behavioral, cognitive and attitudinal aspects of e-cig use in smoking and ex-smoking vapers; (3) Results: Our sample consisted of 19% dual users and 81% switchers. Before e-cig initiation, both groups smoked on average 22 cigarettes per day (CPD). After e-cig initiation, dual users decreased tobacco consumption by 82% and were low-to-moderately cigarette dependent. Both groups had been vaping for on average 22 months, were highly e-cig dependent, used state-of-the-art e-cigs, nicotine concentrations of 4-8 mg/mL and often flavors other than tobacco. Dual users used substantially less e-liquid per week than switchers but reported a similar number of puffs/day, experienced less e-cig efficacy, more practical problems, more negative and less positive consequences, and endorsed smoking reduction (rather than quitting) as a more important reason to start vaping. For both groups, e-cig risk perception was low and little stigmatization was experienced. Dual users preferred tobacco cigarettes in stressful situations and when rapid nicotine uptake is required. E-cigs were preferred where cigarettes are prohibited and to reduce second-hand smoke; (4) Conclusions: Differences between dual users and switchers center around variables proximal to the vaping behavior and its experienced effects rather than hinging on more general vaping-related beliefs and attitudes.

  1. Transfer after Dual n-Back Training Depends on Striatal Activation Change.

    PubMed

    Salminen, Tiina; Kühn, Simone; Frensch, Peter A; Schubert, Torsten

    2016-09-28

    activation in the striatum that is related to WM updating. The current findings challenge the view that dual n-back training provokes a general boosting of the WM system and of its neural underpinnings located in frontoparietal brain regions. Instead, the findings imply the relevance of task-specific brain regions which are involved in important cognitive processes during training and transfer tasks. Copyright © 2016 the authors 0270-6474/16/3610198-16$15.00/0.

  2. New Fukui, dual and hyper-dual kernels as bond reactivity descriptors.

    PubMed

    Franco-Pérez, Marco; Polanco-Ramírez, Carlos-A; Ayers, Paul W; Gázquez, José L; Vela, Alberto

    2017-06-21

    We define three new linear response indices with promising applications for bond reactivity using the mathematical framework of τ-CRT (finite temperature chemical reactivity theory). The τ-Fukui kernel is defined as the ratio between the fluctuations of the average electron density at two different points in the space and the fluctuations in the average electron number and is designed to integrate to the finite-temperature definition of the electronic Fukui function. When this kernel is condensed, it can be interpreted as a site-reactivity descriptor of the boundary region between two atoms. The τ-dual kernel corresponds to the first order response of the Fukui kernel and is designed to integrate to the finite temperature definition of the dual descriptor; it indicates the ambiphilic reactivity of a specific bond and enriches the traditional dual descriptor by allowing one to distinguish between the electron-accepting and electron-donating processes. Finally, the τ-hyper dual kernel is defined as the second-order derivative of the Fukui kernel and is proposed as a measure of the strength of ambiphilic bonding interactions. Although these quantities have never been proposed, our results for the τ-Fukui kernel and for τ-dual kernel can be derived in zero-temperature formulation of the chemical reactivity theory with, among other things, the widely-used parabolic interpolation model.

  3. Dual FOV infrared lens design with the laser common aperture optics

    NASA Astrophysics Data System (ADS)

    Chang, Wei-jun; Zhang, Xuan-zhi; Luan, Ya-dong; Zhang, Bo

    2015-02-01

    With the demand of autonomous precision guidance of air defense missile, the system scheme of the IR imaging/Ladar dual-mode seeker with a common aperture was proposed, and the optical system used in was designed. The system had a common receiving aperture, and its structure was very compact, so it could meet the requirement for the miniaturization of the seeker. Besides, it also could meet the demands of a wide field of view for searching target, and the demands for accurately recognizing and tracking the target at the same time. In order to increase the narrow FOV tracking performance, the dual FOV infrared optical used the zooming mode which some components flip in or out the optical system to firm the target signal. The dual FOV optics are divided into the zooming part, with dual variable focal length, and the reimaging part which was chosen in such a way to minimize the objective lens while maintaining 100% cold shield efficiency. The final infrared optics including 4°×3°(NFOV) and 16°×12°(WFOV) was designed. The NFOV lens composed of two common IR/Ladar lens, three relay lens, a beam splitter and two reflective fold mirrors, while WFOV lens increased two lens such as Germanium and Silicon. The common IR/Ladar lens ZnS and ZnSe could refractive the IR optics and Laser optics. The beam splitter which refractived IR optics and reflected Laser optics was located in the middle of Germanium and Silicon. The designed optical system had good image quality, and fulfilled the performance requirement of seeker system.

  4. Modular synthesis of a dual metal-dual semiconductor nano-heterostructure

    DOE PAGES

    Amirav, Lilac; Oba, Fadekemi; Aloni, Shaul; ...

    2015-04-29

    Reported is the design and modular synthesis of a dual metal-dual semiconductor heterostructure with control over the dimensions and placement of its individual components. Analogous to molecular synthesis, colloidal synthesis is now evolving into a series of sequential synthetic procedures with separately optimized steps. Here we detail the challenges and parameters that must be considered when assembling such a multicomponent nanoparticle, and their solutions.

  5. Hypothesis driven single cell dual oscillator mathematical model of circadian rhythms

    PubMed Central

    S, Shiju

    2017-01-01

    Molecular mechanisms responsible for 24 h circadian oscillations, entrainment to external cues, encoding of day length and the time-of-day effects have been well studied experimentally. However, it is still debated from the molecular network point of view whether each cell in suprachiasmatic nuclei harbors two molecular oscillators, where one tracks dawn and the other tracks dusk activities. A single cell dual morning and evening oscillator was proposed by Daan et al., based on the molecular network that has two sets of similar non-redundant per1/cry1 and per2/cry2 circadian genes and each can independently maintain their endogenous oscillations. Understanding of dual oscillator dynamics in a single cell at molecular level may provide insight about the circadian mechanisms that encodes day length variations and its response to external zeitgebers. We present here a realistic dual oscillator model of circadian rhythms based on the series of hypotheses proposed by Daan et al., in which they conjectured that the circadian genes per1/cry1 track dawn while per2/cry2 tracks dusk and they together constitute the morning and evening oscillators (dual oscillator). Their hypothesis also provides explanations about the encoding of day length in terms of molecular mechanisms of per/cry expression. We frame a minimal mathematical model with the assumption that per1 acts a morning oscillator and per2 acts as an evening oscillator and to support and interpret this assumption we fit the model to the experimental data of per1/per2 circadian temporal dynamics, phase response curves (PRC's), and entrainment phenomena under various light-dark conditions. We also capture different patterns of splitting phenomena by coupling two single cell dual oscillators with neuropeptides vasoactive intestinal polypeptide (VIP) and arginine vasopressin (AVP) as the coupling agents and provide interpretation for the occurrence of splitting in terms of ME oscillators, though they are not required to

  6. Hypothesis driven single cell dual oscillator mathematical model of circadian rhythms.

    PubMed

    S, Shiju; Sriram, K

    2017-01-01

    Molecular mechanisms responsible for 24 h circadian oscillations, entrainment to external cues, encoding of day length and the time-of-day effects have been well studied experimentally. However, it is still debated from the molecular network point of view whether each cell in suprachiasmatic nuclei harbors two molecular oscillators, where one tracks dawn and the other tracks dusk activities. A single cell dual morning and evening oscillator was proposed by Daan et al., based on the molecular network that has two sets of similar non-redundant per1/cry1 and per2/cry2 circadian genes and each can independently maintain their endogenous oscillations. Understanding of dual oscillator dynamics in a single cell at molecular level may provide insight about the circadian mechanisms that encodes day length variations and its response to external zeitgebers. We present here a realistic dual oscillator model of circadian rhythms based on the series of hypotheses proposed by Daan et al., in which they conjectured that the circadian genes per1/cry1 track dawn while per2/cry2 tracks dusk and they together constitute the morning and evening oscillators (dual oscillator). Their hypothesis also provides explanations about the encoding of day length in terms of molecular mechanisms of per/cry expression. We frame a minimal mathematical model with the assumption that per1 acts a morning oscillator and per2 acts as an evening oscillator and to support and interpret this assumption we fit the model to the experimental data of per1/per2 circadian temporal dynamics, phase response curves (PRC's), and entrainment phenomena under various light-dark conditions. We also capture different patterns of splitting phenomena by coupling two single cell dual oscillators with neuropeptides vasoactive intestinal polypeptide (VIP) and arginine vasopressin (AVP) as the coupling agents and provide interpretation for the occurrence of splitting in terms of ME oscillators, though they are not required to

  7. Adiposity and TV viewing are related to less bone accrual in young children.

    PubMed

    Wosje, Karen S; Khoury, Philip R; Claytor, Randal P; Copeland, Kristen A; Kalkwarf, Heidi J; Daniels, Stephen R

    2009-01-01

    To examine the relation between baseline fat mass and gain in bone area and bone mass in preschoolers studied prospectively for 4 years, with a focus on the role of physical activity and TV viewing. Children were part of a longitudinal study in which measures of fat, lean and bone mass, height, weight, activity, and diet were taken every 4 months from ages 3 to 7 years. Activity was measured by accelerometer and TV viewing by parent checklist. We included 214 children with total body dual energy x-ray absorptiometry (Hologic 4500A) scans at ages 3.5 and 7 years. Higher baseline fat mass was associated with smaller increases in bone area and bone mass over the next 3.5 years (P < .001). More TV viewing was related to smaller gains in bone area and bone mass accounting for race, sex, and height. Activity by accelerometer was not associated with bone gains. Adiposity and TV viewing are related to less bone accrual in preschoolers.

  8. Integration of an Apple II Plus Computer into an Existing Dual Axis Sun Tracker System.

    DTIC Science & Technology

    1984-06-01

    Identify by block number) S, tpec l Sun Tracker System Solar Energy Apple II Plus Computer 20. ABSTRACT (’ ntlnue on reveree ide If neceesery end...14 4. Dual Axis Sun Tracker (Side View) ----------------- 15 5. Solar Tracker System Block Diagram ---------------- 17 6. Plug Wiring Diagram for Top...sources will be competitive. Already many homes have solar collectors and other devices designed to decrease the consumption of gas, oil, and

  9. Dual coil ignition system

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Huberts, Garlan J.; Qu, Qiuping; Czekala, Michael Damian

    2017-03-28

    A dual coil ignition system is provided. The dual coil ignition system includes a first inductive ignition coil including a first primary winding and a first secondary winding, and a second inductive ignition coil including a second primary winding and a second secondary winding, the second secondary winding connected in series to the first secondary winding. The dual coil ignition system further includes a diode network including a first diode and a second diode connected between the first secondary winding and the second secondary winding.

  10. Dual-Modulation, Dual-Wavelength, Optical Polarimetry System for Glucose Monitoring

    DTIC Science & Technology

    2016-08-26

    dual-wavelength, optical polarimetry system for glucose monitoring 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER N/A 6. AUTHOR(S) 5d...JBO.21.8.087001] 14. ABSTRACT A dual modulation optical polarimetry system utilizing both laser intensity and polarization modulation was designed...varying birefringence, which is one of the major limitations to the realization of polarimetry for glucose monitoring in the eye. The high-speed less

  11. Differences between Dual Users and Switchers Center around Vaping Behavior and Its Experiences Rather than Beliefs and Attitudes

    PubMed Central

    2017-01-01

    (1) Background: Many smokers completely switch to vaping (switchers), whereas others use e-cigarettes (e-cigs) alongside tobacco cigarettes (dual users). To the extent that dual users substantially lower the number of cigarettes, they will reduce health risks from smoking. However, from a medical point of view, exclusive vaping is preferable to dual use; (2) Methods: Using an online questionnaire we assessed behavioral, cognitive and attitudinal aspects of e-cig use in smoking and ex-smoking vapers; (3) Results: Our sample consisted of 19% dual users and 81% switchers. Before e-cig initiation, both groups smoked on average 22 cigarettes per day (CPD). After e-cig initiation, dual users decreased tobacco consumption by 82% and were low-to-moderately cigarette dependent. Both groups had been vaping for on average 22 months, were highly e-cig dependent, used state-of-the-art e-cigs, nicotine concentrations of 4–8 mg/mL and often flavors other than tobacco. Dual users used substantially less e-liquid per week than switchers but reported a similar number of puffs/day, experienced less e-cig efficacy, more practical problems, more negative and less positive consequences, and endorsed smoking reduction (rather than quitting) as a more important reason to start vaping. For both groups, e-cig risk perception was low and little stigmatization was experienced. Dual users preferred tobacco cigarettes in stressful situations and when rapid nicotine uptake is required. E-cigs were preferred where cigarettes are prohibited and to reduce second-hand smoke; (4) Conclusions: Differences between dual users and switchers center around variables proximal to the vaping behavior and its experienced effects rather than hinging on more general vaping-related beliefs and attitudes. PMID:29295483

  12. Effects of dual tasks and dual-task training on postural stability: a systematic review and meta-analysis

    PubMed Central

    Ghai, Shashank; Ghai, Ishan; Effenberg, Alfred O

    2017-01-01

    The use of dual-task training paradigm to enhance postural stability in patients with balance impairments is an emerging area of interest. The differential effects of dual tasks and dual-task training on postural stability still remain unclear. A systematic review and meta-analysis were conducted to analyze the effects of dual task and training application on static and dynamic postural stability among various population groups. Systematic identification of published literature was performed adhering to Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines, from inception until June 2016, on the online databases Scopus, PEDro, MEDLINE, EMBASE, and SportDiscus. Experimental studies analyzing the effects of dual task and dual-task training on postural stability were extracted, critically appraised using PEDro scale, and then summarized according to modified PEDro level of evidence. Of 1,284 records, 42 studies involving 1,480 participants met the review’s inclusion criteria. Of the studies evaluating the effects of dual-task training on postural stability, 87.5% of the studies reported significant enhancements, whereas 30% of the studies evaluating acute effects of dual tasks on posture reported significant enhancements, 50% reported significant decrements, and 20% reported no effects. Meta-analysis of the pooled studies revealed moderate but significant enhancements of dual-task training in elderly participants (95% CI: 1.16–2.10) and in patients suffering from chronic stroke (−0.22 to 0.86). The adverse effects of complexity of dual tasks on postural stability were also revealed among patients with multiple sclerosis (−0.74 to 0.05). The review also discusses the significance of verbalization in a dual-task setting for increasing cognitive–motor interference. Clinical implications are discussed with respect to practical applications in rehabilitation settings. PMID:28356727

  13. Effects of dual tasks and dual-task training on postural stability: a systematic review and meta-analysis.

    PubMed

    Ghai, Shashank; Ghai, Ishan; Effenberg, Alfred O

    2017-01-01

    The use of dual-task training paradigm to enhance postural stability in patients with balance impairments is an emerging area of interest. The differential effects of dual tasks and dual-task training on postural stability still remain unclear. A systematic review and meta-analysis were conducted to analyze the effects of dual task and training application on static and dynamic postural stability among various population groups. Systematic identification of published literature was performed adhering to Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines, from inception until June 2016, on the online databases Scopus, PEDro, MEDLINE, EMBASE, and SportDiscus. Experimental studies analyzing the effects of dual task and dual-task training on postural stability were extracted, critically appraised using PEDro scale, and then summarized according to modified PEDro level of evidence. Of 1,284 records, 42 studies involving 1,480 participants met the review's inclusion criteria. Of the studies evaluating the effects of dual-task training on postural stability, 87.5% of the studies reported significant enhancements, whereas 30% of the studies evaluating acute effects of dual tasks on posture reported significant enhancements, 50% reported significant decrements, and 20% reported no effects. Meta-analysis of the pooled studies revealed moderate but significant enhancements of dual-task training in elderly participants (95% CI: 1.16-2.10) and in patients suffering from chronic stroke (-0.22 to 0.86). The adverse effects of complexity of dual tasks on postural stability were also revealed among patients with multiple sclerosis (-0.74 to 0.05). The review also discusses the significance of verbalization in a dual-task setting for increasing cognitive-motor interference. Clinical implications are discussed with respect to practical applications in rehabilitation settings.

  14. Dynamic dual-tracer PET reconstruction.

    PubMed

    Gao, Fei; Liu, Huafeng; Jian, Yiqiang; Shi, Pengcheng

    2009-01-01

    Although of important medical implications, simultaneous dual-tracer positron emission tomography reconstruction remains a challenging problem, primarily because the photon measurements from dual tracers are overlapped. In this paper, we propose a simultaneous dynamic dual-tracer reconstruction of tissue activity maps based on guidance from tracer kinetics. The dual-tracer reconstruction problem is formulated in a state-space representation, where parallel compartment models serve as continuous-time system equation describing the tracer kinetic processes of dual tracers, and the imaging data is expressed as discrete sampling of the system states in measurement equation. The image reconstruction problem has therefore become a state estimation problem in a continuous-discrete hybrid paradigm, and H infinity filtering is adopted as the estimation strategy. As H infinity filtering makes no assumptions on the system and measurement statistics, robust reconstruction results can be obtained for the dual-tracer PET imaging system where the statistical properties of measurement data and system uncertainty are not available a priori, even when there are disturbances in the kinetic parameters. Experimental results on digital phantoms, Monte Carlo simulations and physical phantoms have demonstrated the superior performance.

  15. Comparison of Tomo-PIV Versus Dual Plane PIV on a Synthetic Jet Flow

    NASA Technical Reports Server (NTRS)

    Wernet, Mark P.

    2017-01-01

    Particle Imaging Velocimetry (PIV) is a planar velocity measurement technique that has found widespread use across a wide class of engineering disciplines. Tomographic PIV (tomoPIV) is an extension of the traditional PIV technique whereby the velocity across a volume of fluid is measured. TomoPIV provides additional fluid mechanical properties of the flow due to the adjacent planes of velocity information that are extracted. Dual Plane PIV is another approach for providing cross-plane flow field properties. Dual Plane PIV and tomoPIV provide all of the same flow properties, albeit through very different routes with significantly different levels of effort, hence a comparison of their application and performance would prove beneficial in a well-known, highly three dimensional flow field. A synthetic jet flow which has a wide range of flow field features including high velocity gradients and regions of high vorticity was used as a rigorous test bed to determine the capabilities limitations of the Dual Plane PIV and tomoPIV techniques. The results show that compressing 3D particle field information down to a limited number of views does not permit the accurate reconstruction of the flow field. The traditional thin sheet techniques are the best approach for accurate flow field measurements.

  16. Cognitive and motor dual task gait training improve dual task gait performance after stroke - A randomized controlled pilot trial.

    PubMed

    Liu, Yan-Ci; Yang, Yea-Ru; Tsai, Yun-An; Wang, Ray-Yau

    2017-06-22

    This study investigated effects of cognitive and motor dual task gait training on dual task gait performance in stroke. Participants (n = 28) were randomly assigned to cognitive dual task gait training (CDTT), motor dual task gait training (MDTT), or conventional physical therapy (CPT) group. Participants in CDTT or MDTT group practiced the cognitive or motor tasks respectively during walking. Participants in CPT group received strengthening, balance, and gait training. The intervention was 30 min/session, 3 sessions/week for 4 weeks. Three test conditions to evaluate the training effects were single walking, walking while performing cognitive task (serial subtraction), and walking while performing motor task (tray-carrying). Parameters included gait speed, dual task cost of gait speed (DTC-speed), cadence, stride time, and stride length. After CDTT, cognitive-motor dual task gait performance (stride length and DTC-speed) was improved (p = 0.021; p = 0.015). After MDTT, motor dual task gait performance (gait speed, stride length, and DTC-speed) was improved (p = 0.008; p = 0.008; p = 0.008 respectively). It seems that CDTT improved cognitive dual task gait performance and MDTT improved motor dual task gait performance although such improvements did not reach significant group difference. Therefore, different types of dual task gait training can be adopted to enhance different dual task gait performance in stroke.

  17. Accuracy of iodine quantification using dual energy CT in latest generation dual source and dual layer CT.

    PubMed

    Pelgrim, Gert Jan; van Hamersvelt, Robbert W; Willemink, Martin J; Schmidt, Bernhard T; Flohr, Thomas; Schilham, Arnold; Milles, Julien; Oudkerk, Matthijs; Leiner, Tim; Vliegenthart, Rozemarijn

    2017-09-01

    To determine the accuracy of iodine quantification with dual energy computed tomography (DECT) in two high-end CT systems with different spectral imaging techniques. Five tubes with different iodine concentrations (0, 5, 10, 15, 20 mg/ml) were analysed in an anthropomorphic thoracic phantom. Adding two phantom rings simulated increased patient size. For third-generation dual source CT (DSCT), tube voltage combinations of 150Sn and 70, 80, 90, 100 kVp were analysed. For dual layer CT (DLCT), 120 and 140 kVp were used. Scans were repeated three times. Median normalized values and interquartile ranges (IQRs) were calculated for all kVp settings and phantom sizes. Correlation between measured and known iodine concentrations was excellent for both systems (R = 0.999-1.000, p < 0.0001). For DSCT, median measurement errors ranged from -0.5% (IQR -2.0, 2.0%) at 150Sn/70 kVp and -2.3% (IQR -4.0, -0.1%) at 150Sn/80 kVp to -4.0% (IQR -6.0, -2.8%) at 150Sn/90 kVp. For DLCT, median measurement errors ranged from -3.3% (IQR -4.9, -1.5%) at 140 kVp to -4.6% (IQR -6.0, -3.6%) at 120 kVp. Larger phantom sizes increased variability of iodine measurements (p < 0.05). Iodine concentration can be accurately quantified with state-of-the-art DECT systems from two vendors. The lowest absolute errors were found for DSCT using the 150Sn/70 kVp or 150Sn/80 kVp combinations, which was slightly more accurate than 140 kVp in DLCT. • High-end CT scanners allow accurate iodine quantification using different DECT techniques. • Lowest measurement error was found in scans with largest photon energy separation. • Dual-source CT quantified iodine slightly more accurately than dual layer CT.

  18. Parent Involvement and Views of School Success: The Role of Parents' Latino and White American Cultural Orientations

    ERIC Educational Resources Information Center

    Ryan, Carey S.; Casas, Juan F.; Kelly-Vance, Lisa; Ryalls, Brigette O.; Nero, Collette

    2010-01-01

    We examined ethnicity and cultural orientation as predictors of parents' views of and involvement in children's education, using data gathered from the Latino (n = 74) and non-Latino (17 White and 13 ethnic minority) parents of children in an elementary school's dual-language program. Parents completed a questionnaire that assessed Latino and…

  19. Using Stage- and Slit-Scanning to Improve Contrast and Optical Sectioning in Dual-View Inverted Light Sheet Microscopy (diSPIM)

    PubMed Central

    KUMAR, ABHISHEK; CHRISTENSEN, RYAN; GUO, MIN; CHANDRIS, PANOS; DUNCAN, WILLIAM; WU, YICONG; SANTELLA, ANTHONY; MOYLE, MARK; WINTER, PETER W.; COLÓN-RAMOS, DANIEL; BAO, ZHIRONG; SHROFF, HARI

    2017-01-01

    Dual-view inverted selective plane illumination microscopy (diSPIM) enables high-speed, long-term, fourdimensional (4D) imaging with isotropic spatial resolution. It is also compatible with conventional sample mounting on glass coverslips. However, broadening of the light sheet at distances far from the beam waist and sample-induced scattering degrades diSPIM contrast and optical sectioning. We describe two simple improvements that address both issues and entail no additional hardware modifications to the base diSPIM. First, we demonstrate improved diSPIM sectioning by keeping the light sheet and detection optics stationary, and scanning the sample through the stationary light sheet (rather than scanning the broadening light sheet and detection plane through the stationary sample, as in conventional diSPIM). This stage-scanning approach allows a thinner sheet to be used when imaging laterally extended samples, such as fixed microtubules or motile mitochondria in cell monolayers, and produces finer contrast than does conventional diSPIM. We also used stage-scanning diSPIM to obtain high-quality, 4D nuclear datasets derived from an uncompressed nematode embryo, and performed lineaging analysis to track 97% of cells until twitching. Second, we describe the improvement of contrast in thick, scattering specimens by synchronizing light-sheet synthesis with the rolling, electronic shutter of our scientific complementary metal-oxide-semiconductor (sCMOS) detector. This maneuver forms a virtual confocal slit in the detection path, partially removing out-of-focus light. We demonstrate the applicability of our combined stage- and slit-scanning-methods by imaging pollen grains and nuclear and neuronal structures in live nematode embryos. All acquisition and analysis code is freely available online. PMID:27638693

  20. Dual-use technology programs

    NASA Astrophysics Data System (ADS)

    Johns, Lionel S.

    1994-10-01

    The paper presents the Clinton Administration's commitment to American industrial competitiveness through a strategic focus on research and development and to dual-use technologies in particular. Working in partnership with industry, the dual-use approach is essential for giving our armed forces the world's best, most technically advanced military equipment at affordable cost. The President has set a goal of shifting from a dominant role for military technologies in our Federal R&D investments to a roughly equal balance between military on the one hand and civilian and dual-use on the other. We have already made significant progress toward this goal.

  1. Dual Enrollment Academy Programs

    ERIC Educational Resources Information Center

    Gonzalez, Nicolas; Chavez, Guadalupe

    2009-01-01

    Dual Enrollment Engineering (DEEA) and Medical Science (DEMSA) Academies are two-year dual enrollment programs for high school students. Students explore engineering and medical careers through college coursework. Students prepare for higher education in engineering and medical fields while completing associate degrees in biology or engineering…

  2. 46 CFR 120.324 - Dual voltage generators.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Dual voltage generators. 120.324 Section 120.324... INSTALLATION Power Sources and Distribution Systems § 120.324 Dual voltage generators. (a) A dual voltage generator installed on a vessel shall be of the grounded type, where: (1) The neutral of a dual voltage...

  3. Coping in Dual-Employed Families: Spousal Differences.

    ERIC Educational Resources Information Center

    Skinner, Denise A.; McCubbin, Hamilton I.

    The Dual Employed Coping Scales (DECS) were developed to measure coping behaviors and patterns of dual-employed families. The original DECS (58 self-report items) was administered to a sample of 60 individuals in dual-employed families. In another study, in which 69 dual-employed couples completed the DECS and the Family Adaptability and Cohesion…

  4. 46 CFR 129.326 - Dual-voltage generators.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Dual-voltage generators. 129.326 Section 129.326... INSTALLATIONS Power Sources and Distribution Systems § 129.326 Dual-voltage generators. If a dual-voltage generator is installed on an OSV— (a) The neutral of the dual-voltage system must be solidly grounded at the...

  5. Dual Relationships in Counseling.

    ERIC Educational Resources Information Center

    Herlihy, Barbara; Corey, Gerald

    Issues involving dual relationships in counseling are discussed in this monograph. Dual relationships occur when counselors have another, significantly different, relationship with one of their clients, students, or supervisees. This monograph is intended to be a resource that reflects the current thinking of the counseling profession and that…

  6. Dual-Credit in Kentucky

    ERIC Educational Resources Information Center

    Stephenson, Lisa G.

    2013-01-01

    Credit-based transition programs provide high school students with opportunities to jump start their college education. The Kentucky Community and Technical College System (KCTCS) offers college credit through dual-credit programs. While KCTCS dual-credit offerings have been successful in helping high school students start their college education…

  7. Dual nozzle aerodynamic and cooling analysis study

    NASA Technical Reports Server (NTRS)

    Meagher, G. M.

    1981-01-01

    Analytical models to predict performance and operating characteristics of dual nozzle concepts were developed and improved. Aerodynamic models are available to define flow characteristics and bleed requirements for both the dual throat and dual expander concepts. Advanced analytical techniques were utilized to provide quantitative estimates of the bleed flow, boundary layer, and shock effects within dual nozzle engines. Thermal analyses were performed to define cooling requirements for baseline configurations, and special studies of unique dual nozzle cooling problems defined feasible means of achieving adequate cooling.

  8. Dual-Doppler Feasibility Study

    NASA Technical Reports Server (NTRS)

    Huddleston, Lisa L.

    2012-01-01

    When two or more Doppler weather radar systems are monitoring the same region, the Doppler velocities can be combined to form a three-dimensional (3-D) wind vector field thus providing for a more intuitive analysis of the wind field. A real-time display of the 3-D winds can assist forecasters in predicting the onset of convection and severe weather. The data can also be used to initialize local numerical weather prediction models. Two operational Doppler Radar systems are in the vicinity of Kennedy Space Center (KSC) and Cape Canaveral Air Force Station (CCAFS); these systems are operated by the 45th Space Wing (45 SW) and the National Weather Service Melbourne, Fla. (NWS MLB). Dual-Doppler applications were considered by the 45 SW in choosing the site for the new radar. Accordingly, the 45th Weather Squadron (45 WS), NWS MLB and the National Aeronautics and Space Administration tasked the Applied Meteorology Unit (AMU) to investigate the feasibility of establishing dual-Doppler capability using the two existing systems. This study investigated technical, hardware, and software requirements necessary to enable the establishment of a dual-Doppler capability. Review of the available literature pertaining to the dual-Doppler technique and consultation with experts revealed that the physical locations and resulting beam crossing angles of the 45 SW and NWS MLB radars make them ideally suited for a dual-Doppler capability. The dual-Doppler equations were derived to facilitate complete understanding of dual-Doppler synthesis; to determine the technical information requirements; and to determine the components of wind velocity from the equation of continuity and radial velocity data collected by the two Doppler radars. Analysis confirmed the suitability of the existing systems to provide the desired capability. In addition, it is possible that both 45 SW radar data and Terminal Doppler Weather Radar data from Orlando International Airport could be used to alleviate any

  9. Dual agency, dual relationships, boundary crossings, and associated boundary violations: a survey of military and civilian psychiatrists.

    PubMed

    Hines, A H; Ader, D N; Chang, A S; Rundell, J R

    1998-12-01

    We hypothesized that psychiatrists with high dual-agency potential (military and health maintenance organization [HMO] psychiatrists) were more likely than non-HMO civilian psychiatrists to engage in dual relationships, report pressures to do so, participate in other general boundary-crossing activities, and report associated counter-therapeutic outcomes (boundary violations). Ninety military and 191 demographically matched civilian psychiatrists reported the number of boundary-crossing activities (including dual relationships) and associated counter-therapeutic outcomes in the preceding year with adult patients. Military and HMO psychiatrists reported greater external pressures than non-HMO civilian psychiatrists to engage in dual relationships; however, all three groups were similar in their reported numbers of dual relationships. The reported boundary-crossing activities and dual relationships studied here are not necessarily associated with reported boundary violations. The relative risk of a particular boundary crossing associating with harm to a patient likely depends on the therapeutic context and should be determined on a case-by-case basis.

  10. Synergistic stress exacerbation in hippocampal neurons: Evidence favoring the dual-hit hypothesis of neurodegeneration.

    PubMed

    Heinemann, Scott D; Posimo, Jessica M; Mason, Daniel M; Hutchison, Daniel F; Leak, Rehana K

    2016-08-01

    The dual-hit hypothesis of neurodegeneration states that severe stress sensitizes vulnerable cells to subsequent challenges so that the two hits are synergistic in their toxic effects. Although the hippocampus is vulnerable to a number of neurodegenerative disorders, there are no models of synergistic cell death in hippocampal neurons in response to combined proteotoxic and oxidative stressors, the two major characteristics of these diseases. Therefore, a relatively high-throughput dual-hit model of stress synergy was developed in primary hippocampal neurons. In order to increase the rigor of the study and strengthen the interpretations, three independent, unbiased viability assays were employed at multiple timepoints. Stress synergy was elicited when hippocampal neurons were treated with the proteasome inhibitor MG132 followed by exposure to the oxidative toxicant paraquat, but only after 48 h. MG132 and paraquat only elicited additive effects 24 h after the final hit and even loss of heat shock protein 70 activity and glutathione did not promote stress synergy at this early timepoint. Dual hits of MG132 elicited modest glutathione loss and slightly synergistic toxic effects 48 h after the second hit, but only at some concentrations and only according to two viability assays (metabolic fitness and cytoskeletal integrity). The thiol N-acetyl cysteine protected hippocampal neurons against dual MG132/MG132 hits but not dual MG132/paraquat hits. These findings support the view that proteotoxic and oxidative stress propel and propagate each other in hippocampal neurons, leading to synergistically toxic effects, but not as the default response and only after a delay. The neuronal stress synergy observed here lies in contrast to astrocytic responses to dual hits, because astrocytes that survive severe proteotoxic stress resist additional cell loss following second hits. In conclusion, a new model of hippocampal vulnerability was developed for the testing of therapies

  11. Synergistic stress exacerbation in hippocampal neurons: Evidence favoring the dual hit hypothesis of neurodegeneration

    PubMed Central

    Heinemann, Scott D.; Posimo, Jessica M.; Mason, Daniel M.; Hutchison, Daniel F.; Leak, Rehana K.

    2016-01-01

    The dual hit hypothesis of neurodegeneration states that severe stress sensitizes vulnerable cells to subsequent challenges so that the two hits are synergistic in their toxic effects. Although the hippocampus is vulnerable to a number of neurodegenerative disorders, there are no models of synergistic cell death in hippocampal neurons in response to combined proteotoxic and oxidative stressors, the two major characteristics of these diseases. Therefore, we developed a relatively high-throughput dual hit model of stress synergy in primary hippocampal neurons. In order to increase the rigor of our study and strengthen our interpretations, we employed three independent, unbiased viability assays at multiple timepoints. Stress synergy was elicited when hippocampal neurons were treated with the proteasome inhibitor MG132 followed by exposure to the oxidative toxicant paraquat, but only after 48h. MG132 and paraquat only elicited additive effects 24h after the final hit and even loss of heat shock protein 70 activity and glutathione did not promote stress synergy at this early timepoint. Dual hits of MG132 elicited modest glutathione loss and slightly synergistic toxic effects 48h after the second hit, but only at some concentrations and only according to two viability assays (metabolic fitness and cytoskeletal integrity). The thiol N-acetyl cysteine protected hippocampal neurons against dual MG132/MG132 hits but not dual MG132/paraquat hits. Our findings support the view that proteotoxic and oxidative stress propel and propagate each other in hippocampal neurons, leading to synergistically toxic effects, but not as the default response and only after a delay. The neuronal stress synergy observed here lies in contrast to astrocytic responses to dual hits, because astrocytes that survive severe proteotoxic stress resist additional cell loss following second hits. In conclusion, we present a new model of hippocampal vulnerability in which to test therapies, because

  12. Validation of ALK/ROS1 Dual Break Apart FISH Probe probe in non-small-cell lung cancer.

    PubMed

    Lim, Sun Min; Chang, Hyun; Cha, Yoon Jin; Liang, Shile; Tai, Yan Chin; Li, Gu; Pestova, Ekaterina; Policht, Frank; Perez, Thomas; Soo, Ross A; Park, Won Young; Kim, Hye Ryun; Shim, Hyo Sup; Cho, Byoung Chul

    2017-09-01

    ALK and ROS1 gene rearrangements are distinct molecular subsets of non-small-cell lung cancer (NSCLC), and they are strong predictive biomarkers of response to ALK/ROS1 inhibitors, such as crizotinib. Thus, it is clinically important to develop an effective screening strategy to detect patients who will benefit from such treatment. In this study, we aimed to validate analytical performance of Vysis ALK/ROS1 Dual Break Apart Probe Kit (RUO) in NSCLC. Study population composed of three patient cohorts with histologically confirmed lung adenocarcinoma (patients with ALK rearrangement, patients with ROS1 rearrangement and patients with wild-type ALK and ROS1). Specimens consisted of 12 ALK-positive, 8 ROS1-positive and 21 ALK/ROS1-wild type formalin-fixed paraffin-embedded samples obtained from surgical resection or excisional biopsy. ALK rearrangement was previously assessed by Vysis ALK Break Apart FISH Probe Kit (Abbott Molecular, Abbot Park, IL, USA) and ROS1 rearrangement was previously assessed by ZytoLight ® SPEC ROS1 Break Apart Probe (ZytoVision, GmbH). All specimens were re-evaluated by Vysis ALK/ROS1 Dual Break Apart Probe Kit. FISH images were scanned on BioView AllegroPlus system and interpreted via BioView SoloWeb remotely. For a total of 41 patient samples, the concordance of the results by Vysis ALK/ROS1 Dual Break Apart Probe Kit was evaluated and compared to the known ALK and ROS1 rearrangement status of the specimen. Of the 12 ALK-positive cases, hybridization with Vysis ALK/ROS1 Dual Break Apart Probe Kit was successful in 10 cases (success rate 10/12, 83%) and of these 10 cases, all showed ALK rearrangement (100% concordance with the results of Vysis ALK Break Apart FISH Probe Kit). Two of the ALK+ cases were excluded due to weak ROS1 signals that could not be enumerated. Of the 8 ROS1-positive cases, 6 cases were successfully evaluated using Vysis ALK/ROS1 Dual Break Apart Probe Kit. The success rate was 75% (6/8), and of these 6 cases, all

  13. Adiposity and TV viewing are related to less bone accrual in young children

    PubMed Central

    Wosje, Karen S.; Khoury, Philip R.; Claytor, Randal P.; Copeland, Kristen A.; Kalkwarf, Heidi J.; Daniels, Stephen R.

    2008-01-01

    Objective To examine the relation between baseline fat mass and gain in bone area and bone mass in preschoolers studied prospectively for 4 y, with a focus on the role of physical activity and TV viewing. Study design Children were part of a longitudinal study in which measures of fat, lean and bone mass, height, weight, activity, and diet were taken every 4 months from ages 3 to 7 y. Activity was measured by accelerometer, and TV viewing by parent checklist. We included 214 children with total body dual energy x-ray absorptiometry (Hologic 4500A) scans at ages 3.5 and 7 y. Results Higher baseline fat mass was associated with smaller increases in bone area and bone mass over the next 3.5 y (p<0.001). More TV viewing was related to smaller gains in bone area and bone mass accounting for race, sex, and height. Activity by accelerometer was not associated with bone gains. Conclusions Adiposity and TV viewing are related to less bone accrual in preschoolers. PMID:18692201

  14. Design of visible and IR infrared dual-band common-path telescope system

    NASA Astrophysics Data System (ADS)

    Guo, YuLin; Yu, Xun; Tao, Yu; Jiang, Xu

    2018-01-01

    The use of visible and IR infrared dual-band combination can effectively improve the performance of photoelectric detection system,TV and IR system were designed with the common path by the common reflection optical system.A TV/IR infrared common-caliber and common-path system is designed,which can realize the Remote and all-day information.For the 640×512 cooled focal plane array,an infrared middle wave system was presented with a focal length of 600mm F number of 4 field of view(FOV) of 0.38°×0.43°, the system uses optical passive thermal design, has o compact structure and can meet 100% cold shield efficiency,meanwhile it meets the design requirements of lightweight and athermalization. For the 1920×1080 pixels CCD,a visible (TV) system ,which had 500mm focal length, 4F number,was completed.The final optical design along with their modulation transfer function is presented,showing excellent imaging performance in dual-band at the temperature range between -40° and 60°.

  15. Dual-modality imaging

    NASA Astrophysics Data System (ADS)

    Hasegawa, Bruce; Tang, H. Roger; Da Silva, Angela J.; Wong, Kenneth H.; Iwata, Koji; Wu, Max C.

    2001-09-01

    In comparison to conventional medical imaging techniques, dual-modality imaging offers the advantage of correlating anatomical information from X-ray computed tomography (CT) with functional measurements from single-photon emission computed tomography (SPECT) or with positron emission tomography (PET). The combined X-ray/radionuclide images from dual-modality imaging can help the clinician to differentiate disease from normal uptake of radiopharmaceuticals, and to improve diagnosis and staging of disease. In addition, phantom and animal studies have demonstrated that a priori structural information from CT can be used to improve quantification of tissue uptake and organ function by correcting the radionuclide data for errors due to photon attenuation, partial volume effects, scatter radiation, and other physical effects. Dual-modality imaging therefore is emerging as a method of improving the visual quality and the quantitative accuracy of radionuclide imaging for diagnosis of patients with cancer and heart disease.

  16. Dual-polarization and dual-mode orbital angular momentum radio vortex beam generated by using reflective metasurface

    NASA Astrophysics Data System (ADS)

    Yu, Shixing; Li, Long; Shi, Guangming

    2016-08-01

    A metasurface, which is composed of printed cross-dipole elements with different arm lengths, is designed, fabricated, and experimentally demonstrated to generate orbital angular momentum (OAM) vortex waves of dual polarizations and dual modes in the radio frequency domain simultaneously. The prototype of a practical metasurface is fabricated and measured to validate the results of theoretical analysis and design at 5.8 GHz. Numerical and experimental results verify that vortex waves with dual OAM modes and dual polarizations can be flexibly generated by using a reflective metasurface. The proposed method paves a way to generate diverse OAM vortex waves for radio frequency and microwave wireless communication applications.

  17. Effect of Long-term Care Use on Medicare and Medicaid Expenditures for Dual Eligible and Non-dual Eligible Elderly Beneficiaries

    PubMed Central

    Kane, Robert L; Wysocki, Andrea; Parashuram, Shriram; Shippee, Tetyana; Lum, Terry

    2013-01-01

    Background: Dual eligible Medicare and Medicaid beneficiaries consume disproportionate shares of both programs. Objectives: To compare Medicare and Medicaid expenditures of elderly dual eligible beneficiaries with non-dual eligible beneficiaries based on their long-term care (LTC) use. Research Design: Secondary analysis of linked MAX and Medicare data in seven states. Subjects: Dual eligible adults (65+) receiving LTC in institutions, in the community, or not at all; and Medicare non-dual eligibles. Measures: Medicaid acute medical and LTC expenditures per beneficiary year, Medicare expenditures. Results: Among dual eligibles and non-dual eligibles, the average number of diseases and case mix scores are higher for LTC users. Adjusting for case mix virtually eliminates the difference for medical costs, but not for LTC expenditures. Adjusting for LTC status reduces the difference in LTC costs, but increases the difference in medical costs. Conclusions: Efforts to control costs for dual eligibles should target those in LTC while better coordinating medical and LTC expenditures. PMID:24753971

  18. Decentralized Sliding Mode Observer Based Dual Closed-Loop Fault Tolerant Control for Reconfigurable Manipulator against Actuator Failure.

    PubMed

    Zhao, Bo; Li, Chenghao; Liu, Derong; Li, Yuanchun

    2015-01-01

    This paper considers a decentralized fault tolerant control (DFTC) scheme for reconfigurable manipulators. With the appearance of norm-bounded failure, a dual closed-loop trajectory tracking control algorithm is proposed on the basis of the Lyapunov stability theory. Characterized by the modularization property, the actuator failure is estimated by the proposed decentralized sliding mode observer (DSMO). Moreover, the actuator failure can be treated in view of the local joint information, so its control performance degradation is independent of other normal joints. In addition, the presented DFTC scheme is significantly simplified in terms of the structure of the controller due to its dual closed-loop architecture, and its feasibility is highly reflected in the control of reconfigurable manipulators. Finally, the effectiveness of the proposed DFTC scheme is demonstrated using simulations.

  19. Decentralized Sliding Mode Observer Based Dual Closed-Loop Fault Tolerant Control for Reconfigurable Manipulator against Actuator Failure

    PubMed Central

    Zhao, Bo; Li, Yuanchun

    2015-01-01

    This paper considers a decentralized fault tolerant control (DFTC) scheme for reconfigurable manipulators. With the appearance of norm-bounded failure, a dual closed-loop trajectory tracking control algorithm is proposed on the basis of the Lyapunov stability theory. Characterized by the modularization property, the actuator failure is estimated by the proposed decentralized sliding mode observer (DSMO). Moreover, the actuator failure can be treated in view of the local joint information, so its control performance degradation is independent of other normal joints. In addition, the presented DFTC scheme is significantly simplified in terms of the structure of the controller due to its dual closed-loop architecture, and its feasibility is highly reflected in the control of reconfigurable manipulators. Finally, the effectiveness of the proposed DFTC scheme is demonstrated using simulations. PMID:26181826

  20. Dual Career Couples in Academia, International Mobility and Dual Career Services in Europe

    ERIC Educational Resources Information Center

    Tzanakou, Charikleia

    2017-01-01

    The number of dual career couples in academia is growing due to the increasing proportion of women with a doctoral degree and the greater propensity of women to choose another academic as their partner. At the same time, international mobility is required for career advancement in academia, creating challenges for dual career couples where both…

  1. Vastly accelerated linear least-squares fitting with numerical optimization for dual-input delay-compensated quantitative liver perfusion mapping.

    PubMed

    Jafari, Ramin; Chhabra, Shalini; Prince, Martin R; Wang, Yi; Spincemaille, Pascal

    2018-04-01

    To propose an efficient algorithm to perform dual input compartment modeling for generating perfusion maps in the liver. We implemented whole field-of-view linear least squares (LLS) to fit a delay-compensated dual-input single-compartment model to very high temporal resolution (four frames per second) contrast-enhanced 3D liver data, to calculate kinetic parameter maps. Using simulated data and experimental data in healthy subjects and patients, whole-field LLS was compared with the conventional voxel-wise nonlinear least-squares (NLLS) approach in terms of accuracy, performance, and computation time. Simulations showed good agreement between LLS and NLLS for a range of kinetic parameters. The whole-field LLS method allowed generating liver perfusion maps approximately 160-fold faster than voxel-wise NLLS, while obtaining similar perfusion parameters. Delay-compensated dual-input liver perfusion analysis using whole-field LLS allows generating perfusion maps with a considerable speedup compared with conventional voxel-wise NLLS fitting. Magn Reson Med 79:2415-2421, 2018. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

  2. Dual-use review policies of biomedical research journals.

    PubMed

    Resnik, David B; Barner, Dionne D; Dinse, Gregg E

    2011-03-01

    To address biosecurity issues, government agencies, academic institutions, and professional societies have developed policies concerning the publication of "dual-use" biomedical research-that is, research that could be readily applied to cause significant harm to the public, the environment, or national security. We conducted an e-mail survey of life science journals to determine the percentage that have a dual-use policy. Of the 155 journals that responded to our survey (response rate 39%), only 7.7% stated that they had a written dual-use policy and only 5.8% said they had experience reviewing dual-use research in the past 5 years. Among the potential predictors we investigated, the one most highly associated with a journal having a written dual-use policy was membership in the Nature Publishing Group (positive association). When considered individually, both previous experience with reviewing dual-use research and the journal's impact factor appeared to be positively associated with having a written dual-use policy, but only the former remained significant after adjusting for publishing group. Although preventing the misuse of scientific research for terrorist or criminal purposes is an important concern, few biomedical journals have dual-use review policies. Journals that are likely to review research that raises potential dual-use concerns should consider developing dual-use policies.

  3. Dual-Energy CT: New Horizon in Medical Imaging

    PubMed Central

    Goo, Jin Mo

    2017-01-01

    Dual-energy CT has remained underutilized over the past decade probably due to a cumbersome workflow issue and current technical limitations. Clinical radiologists should be made aware of the potential clinical benefits of dual-energy CT over single-energy CT. To accomplish this aim, the basic principle, current acquisition methods with advantages and disadvantages, and various material-specific imaging methods as clinical applications of dual-energy CT should be addressed in detail. Current dual-energy CT acquisition methods include dual tubes with or without beam filtration, rapid voltage switching, dual-layer detector, split filter technique, and sequential scanning. Dual-energy material-specific imaging methods include virtual monoenergetic or monochromatic imaging, effective atomic number map, virtual non-contrast or unenhanced imaging, virtual non-calcium imaging, iodine map, inhaled xenon map, uric acid imaging, automatic bone removal, and lung vessels analysis. In this review, we focus on dual-energy CT imaging including related issues of radiation exposure to patients, scanning and post-processing options, and potential clinical benefits mainly to improve the understanding of clinical radiologists and thus, expand the clinical use of dual-energy CT; in addition, we briefly describe the current technical limitations of dual-energy CT and the current developments of photon-counting detector. PMID:28670151

  4. Dual education and industrial cooperation in electrical engineering

    NASA Astrophysics Data System (ADS)

    Váradiné Szarka, A.

    2016-11-01

    Dual education in higher education is a new system in Hungary introduced by Mercedes Benz with cooperation of Kecskemet College. In the new system companies support certain number of students and provide them strong practical education in their field. Students applying successfully for dual education study together with non-dual students at the university, so they go through the same university courses as their non-dual colleagues, but while non-dual students’ academic year includes 2×14 weeks active semester and 2×6 weeks exam session, all over 40 weeks, dual students have 48 working weeks including study at the university and practicing at the company. The main question of the success which one is the most effective model to be applied. This paper summarises 2 models of dual education with their advantages and disadvantages and also it presents practical realization at the University of Debrecen with special attention to measurement and instrumentation. Dual education in BSc level electrical engineering course cooperates with 6 multinational companies of the region in four specialization. Dual education also has great impact to the modernisation of engineering education. Detailed study of dual education in field of instrumentation and measurement is provided in the paper.

  5. Dual-domain point diffraction interferometer

    DOEpatents

    Naulleau, Patrick P.; Goldberg, Kenneth Alan

    2000-01-01

    A hybrid spatial/temporal-domain point diffraction interferometer (referred to as the dual-domain PS/PDI) that is capable of suppressing the scattered-reference-light noise that hinders the conventional PS/PDI is provided. The dual-domain PS/PDI combines the separate noise-suppression capabilities of the widely-used phase-shifting and Fourier-transform fringe pattern analysis methods. The dual-domain PS/PDI relies on both a more restrictive implementation of the image plane PS/PDI mask and a new analysis method to be applied to the interferograms generated and recorded by the modified PS/PDI. The more restrictive PS/PDI mask guarantees the elimination of spatial-frequency crosstalk between the signal and the scattered-light noise arising from scattered-reference-light interfering with the test beam. The new dual-domain analysis method is then used to eliminate scattered-light noise arising from both the scattered-reference-light interfering with the test beam and the scattered-reference-light interfering with the "true" pinhole-diffracted reference light. The dual-domain analysis method has also been demonstrated to provide performance enhancement when using the non-optimized standard PS/PDI design. The dual-domain PS/PDI is essentially a three-tiered filtering system composed of lowpass spatial-filtering the test-beam electric field using the more restrictive PS/PDI mask, bandpass spatial-filtering the individual interferogram irradiance frames making up the phase-shifting series, and bandpass temporal-filtering the phase-shifting series as a whole.

  6. Dual symmetry in a generalized Maxwell theory

    NASA Astrophysics Data System (ADS)

    Brandt, F. T.; Frenkel, J.; McKeon, D. G. C.

    2016-09-01

    We examine Podolsky’s electrodynamics, which is non-invariant under the usual duality transformation. We deduce a generalization of Hodge’s star duality, which leads to a dual gauge field and restores to a certain extent the dual symmetry. The model becomes fully dual symmetric asymptotically, when it reduces to the Maxwell theory. We argue that this strict dual symmetry directly implies the existence of the basic invariants of the electromagnetic fields.

  7. Dual-Use Review Policies of Biomedical Research Journals

    PubMed Central

    Barner, Dionne D.; Dinse, Gregg E.

    2011-01-01

    To address biosecurity issues, government agencies, academic institutions, and professional societies have developed policies concerning the publication of “dual-use” biomedical research—that is, research that could be readily applied to cause significant harm to the public, the environment, or national security. We conducted an e-mail survey of life science journals to determine the percentage that have a dual-use policy. Of the 155 journals that responded to our survey (response rate 39%), only 7.7% stated that they had a written dual-use policy and only 5.8% said they had experience reviewing dual-use research in the past 5 years. Among the potential predictors we investigated, the one most highly associated with a journal having a written dual-use policy was membership in the Nature Publishing Group (positive association). When considered individually, both previous experience with reviewing dual-use research and the journal's impact factor appeared to be positively associated with having a written dual-use policy, but only the former remained significant after adjusting for publishing group. Although preventing the misuse of scientific research for terrorist or criminal purposes is an important concern, few biomedical journals have dual-use review policies. Journals that are likely to review research that raises potential dual-use concerns should consider developing dual-use policies. PMID:21395429

  8. Homophobia: An Impulsive Attraction to the Same Sex? Evidence From Eye-Tracking Data in a Picture-Viewing Task.

    PubMed

    Cheval, Boris; Radel, Remi; Grob, Emmanuelle; Ghisletta, Paolo; Bianchi-Demicheli, Francesco; Chanal, Julien

    2016-05-01

    Some models suggest that homophobia can be explained as a denied attraction toward same-sex individuals. While it has been found that homophobic men have same-sex attraction, these results are not consistent. This study drew on the dual-process models to test the assumption that sexual interest in homosexual cues among men high in homophobia will depend on their specific impulses toward homosexual-related stimuli. Heterosexual men (N = 38) first completed a scale measuring their level of homonegativity. Then, they performed a manikin task to evaluate their impulsive approach tendencies toward homosexual stimuli (IAHS). A picture-viewing task was performed with simultaneous eye-tracking recording to assess participants' viewing time of the visual area of interest (i.e., face and body). IAHS positively predicted the viewing time of homosexual photographs among men with a high score of homonegativity. Men with a high homonegativity score looked significantly longer at homosexual than at heterosexual photographs but only when they had a high IAHS. These findings confirm the importance of considering the variability in impulsive processes to understand why some (but not all) men high in homophobia have homosexual interest. These findings reinforce the theoretical basis for elaborating a dual-process model for behaviors in the sexual context. Copyright © 2016 International Society for Sexual Medicine. Published by Elsevier Inc. All rights reserved.

  9. Running at Double Pace: Women in Dual-Profession Marriages.

    ERIC Educational Resources Information Center

    Arfken, Deborah Elwell

    Although the problems facing dual-profession couples are almost universally acknowledged, studies on dual-profession couples have only recently emerged from those on dual-worker or dual-career families. To explore the perceptions that women in dual-profession marriages have of their roles, conflicts, and coping strategies, focus group interviews…

  10. An innovative strategy for dual inhibitor design and its application in dual inhibition of human thymidylate synthase and dihydrofolate reductase enzymes.

    PubMed

    Arooj, Mahreen; Sakkiah, Sugunadevi; Cao, Guang ping; Lee, Keun Woo

    2013-01-01

    Due to the diligence of inherent redundancy and robustness in many biological networks and pathways, multitarget inhibitors present a new prospect in the pharmaceutical industry for treatment of complex diseases. Nevertheless, to design multitarget inhibitors is concurrently a great challenge for medicinal chemists. We have developed a novel computational approach by integrating the affinity predictions from structure-based virtual screening with dual ligand-based pharmacophore to discover potential dual inhibitors of human Thymidylate synthase (hTS) and human dihydrofolate reductase (hDHFR). These are the key enzymes in folate metabolic pathway that is necessary for the biosynthesis of RNA, DNA, and protein. Their inhibition has found clinical utility as antitumor, antimicrobial, and antiprotozoal agents. A druglike database was utilized to perform dual-target docking studies. Hits identified through docking experiments were mapped over a dual pharmacophore which was developed from experimentally known dual inhibitors of hTS and hDHFR. Pharmacophore mapping procedure helped us in eliminating the compounds which do not possess basic chemical features necessary for dual inhibition. Finally, three structurally diverse hit compounds that showed key interactions at both active sites, mapped well upon the dual pharmacophore, and exhibited lowest binding energies were regarded as possible dual inhibitors of hTS and hDHFR. Furthermore, optimization studies were performed for final dual hit compound and eight optimized dual hits demonstrating excellent binding features at target systems were also regarded as possible dual inhibitors of hTS and hDHFR. In general, the strategy used in the current study could be a promising computational approach and may be generally applicable to other dual target drug designs.

  11. An Innovative Strategy for Dual Inhibitor Design and Its Application in Dual Inhibition of Human Thymidylate Synthase and Dihydrofolate Reductase Enzymes

    PubMed Central

    Arooj, Mahreen; Sakkiah, Sugunadevi; Cao, Guang ping; Lee, Keun Woo

    2013-01-01

    Due to the diligence of inherent redundancy and robustness in many biological networks and pathways, multitarget inhibitors present a new prospect in the pharmaceutical industry for treatment of complex diseases. Nevertheless, to design multitarget inhibitors is concurrently a great challenge for medicinal chemists. We have developed a novel computational approach by integrating the affinity predictions from structure-based virtual screening with dual ligand-based pharmacophore to discover potential dual inhibitors of human Thymidylate synthase (hTS) and human dihydrofolate reductase (hDHFR). These are the key enzymes in folate metabolic pathway that is necessary for the biosynthesis of RNA, DNA, and protein. Their inhibition has found clinical utility as antitumor, antimicrobial, and antiprotozoal agents. A druglike database was utilized to perform dual-target docking studies. Hits identified through docking experiments were mapped over a dual pharmacophore which was developed from experimentally known dual inhibitors of hTS and hDHFR. Pharmacophore mapping procedure helped us in eliminating the compounds which do not possess basic chemical features necessary for dual inhibition. Finally, three structurally diverse hit compounds that showed key interactions at both active sites, mapped well upon the dual pharmacophore, and exhibited lowest binding energies were regarded as possible dual inhibitors of hTS and hDHFR. Furthermore, optimization studies were performed for final dual hit compound and eight optimized dual hits demonstrating excellent binding features at target systems were also regarded as possible dual inhibitors of hTS and hDHFR. In general, the strategy used in the current study could be a promising computational approach and may be generally applicable to other dual target drug designs. PMID:23577115

  12. Hybrid ultrasound and dual-wavelength optoacoustic biomicroscopy for functional neuroimaging

    NASA Astrophysics Data System (ADS)

    Rebling, Johannes; Estrada, Hector; Zwack, Michael; Sela, Gali; Gottschalk, Sven; Razansky, Daniel

    2017-03-01

    Many neurological disorders are linked to abnormal activation or pathological alterations of the vasculature in the affected brain region. Obtaining simultaneous morphological and physiological information of neurovasculature is very challenging due to the acoustic distortions and intense light scattering by the skull and brain. In addition, the size of cerebral vasculature in murine brains spans an extended range from just a few microns up to about a millimeter, all to be recorded in 3D and over an area of several dozens of mm2. Numerous imaging techniques exist that excel at characterizing certain aspects of this complex network but are only capable of providing information on a limited spatiotemporal scale. We present a hybrid ultrasound and dual-wavelength optoacoustic microscope, capable of rapid imaging of murine neurovasculature in-vivo, with high spatial resolution down to 12 μm over a large field of view exceeding 50mm2. The dual wavelength imaging capability allows for the visualization of functional blood parameters through an intact skull while pulse-echo ultrasound biomicroscopy images are captured simultaneously by the same scan head. The flexible hybrid design in combination with fast high-resolution imaging in 3D holds promise for generating better insights into the architecture and function of the neurovascular system.

  13. Performance Enhancements Under Dual-task Conditions

    NASA Technical Reports Server (NTRS)

    Kramer, A. F.; Wickens, C. D.; Donchin, E.

    1984-01-01

    Research on dual-task performance has been concerned with delineating the antecedent conditions which lead to dual-task decrements. Capacity models of attention, which propose that a hypothetical resource structure underlies performance, have been employed as predictive devices. These models predict that tasks which require different processing resources can be more successfully time shared than tasks which require common resources. The conditions under which such dual-task integrality can be fostered were assessed in a study in which three factors likely to influence the integrality between tasks were manipulated: inter-task redundancy, the physical proximity of tasks and the task relevant objects. Twelve subjects participated in three experimental sessions in which they performed both single and dual-tasks. The primary task was a pursuit step tracking task. The secondary tasks required the discrimination between different intensities or different spatial positions of a stimulus. The results are discussed in terms of a model of dual-task integrality.

  14. Dual-fuel, dual-mode rocket engine

    NASA Technical Reports Server (NTRS)

    Martin, James A. (Inventor)

    1989-01-01

    The invention relates to a dual fuel, dual mode rocket engine designed to improve the performance of earth-to-orbit vehicles. For any vehicle that operates from the earth's surface to earth orbit, it is advantageous to use two different fuels during its ascent. A high density impulse fuel, such as kerosene, is most efficient during the first half of the trajectory. A high specific impulse fuel, such as hydrogen, is most efficient during the second half of the trajectory. The invention allows both fuels to be used with a single rocket engine. It does so by adding a minimum number of state-of-the-art components to baseline single made rocket engines, and is therefore relatively easy to develop for near term applications. The novelty of this invention resides in the mixing of fuels before exhaust nozzle cooling. This allows all of the engine fuel to cool the exhaust nozzle, and allows the ratio of fuels used throughout the flight depend solely on performance requirements, not cooling requirements.

  15. Peptides with Dual Antimicrobial and Anticancer Activities

    NASA Astrophysics Data System (ADS)

    Felício, Mário R.; Silva, Osmar N.; Gonçalves, Sônia; Santos, Nuno C.; Franco, Octávio L.

    2017-02-01

    In recent years, the number of people suffering from cancer and multi-resistant infections has increased, such that both diseases are already seen as current and future major causes of death. Moreover, chronic infections are one of the main causes of cancer, due to the instability in the immune system that allows cancer cells to proliferate. Likewise, the physical debility associated with cancer or with anticancer therapy itself often paves the way for opportunistic infections. It is urgent to develop new therapeutic methods, with higher efficiency and lower side effects. Antimicrobial peptides (AMPs) are found in the innate immune system of a wide range of organisms. Identified as the most promising alternative to conventional molecules used nowadays against infections, some of them have been shown to have dual activity, both as antimicrobial and anticancer peptides (ACPs). Highly cationic and amphipathic, they have demonstrated efficacy against both conditions, with the number of nature-driven or synthetically designed peptides increasing year by year. With similar properties, AMPs that can also act as ACPs are viewed as future chemotherapeutic drugs, with the advantage of low propensity to resistance, which started this paradigm in the pharmaceutical market. These peptides have already been described as molecules presenting killing mechanisms at the membrane level, but also acting towards intracellular targets, which increases their success comparatively to specific one-target drugs. This review will approach the desirable characteristics of small peptides that demonstrated dual activity against microbial infections and cancer, as well as the peptides engaged in clinical trials.

  16. Dual-Mode Combustor

    NASA Technical Reports Server (NTRS)

    Trefny, Charles J (Inventor); Dippold, Vance F (Inventor)

    2013-01-01

    A new dual-mode ramjet combustor used for operation over a wide flight Mach number range is described. Subsonic combustion mode is usable to lower flight Mach numbers than current dual-mode scramjets. High speed mode is characterized by supersonic combustion in a free-jet that traverses the subsonic combustion chamber to a variable nozzle throat. Although a variable combustor exit aperture is required, the need for fuel staging to accommodate the combustion process is eliminated. Local heating from shock-boundary-layer interactions on combustor walls is also eliminated.

  17. Miniature near-infrared dual-axes confocal microscope utilizing a two-dimensional microelectromechanical systems scanner

    PubMed Central

    Liu, Jonathan T. C.; Mandella, Michael J.; Ra, Hyejun; Wong, Larry K.; Solgaard, Olav; Kino, Gordon S.; Piyawattanametha, Wibool; Contag, Christopher H.; Wang, Thomas D.

    2007-01-01

    The first, to our knowledge, miniature dual-axes confocal microscope has been developed, with an outer diameter of 10 mm, for subsurface imaging of biological tissues with 5–7 μm resolution. Depth-resolved en face images are obtained at 30 frames per second, with a field of view of 800 × 100 μm, by employing a two-dimensional scanning microelectromechanical systems mirror. Reflectance and fluorescence images are obtained with a laser source at 785 nm, demonstrating the ability to perform real-time optical biopsy. PMID:17215937

  18. 46 CFR 129.326 - Dual-voltage generators.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Dual-voltage generators. 129.326 Section 129.326 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS ELECTRICAL INSTALLATIONS Power Sources and Distribution Systems § 129.326 Dual-voltage generators. If a dual-voltage...

  19. 46 CFR 129.326 - Dual-voltage generators.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Dual-voltage generators. 129.326 Section 129.326 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS ELECTRICAL INSTALLATIONS Power Sources and Distribution Systems § 129.326 Dual-voltage generators. If a dual-voltage...

  20. 46 CFR 129.326 - Dual-voltage generators.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Dual-voltage generators. 129.326 Section 129.326 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS ELECTRICAL INSTALLATIONS Power Sources and Distribution Systems § 129.326 Dual-voltage generators. If a dual-voltage...

  1. 46 CFR 129.326 - Dual-voltage generators.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Dual-voltage generators. 129.326 Section 129.326 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS ELECTRICAL INSTALLATIONS Power Sources and Distribution Systems § 129.326 Dual-voltage generators. If a dual-voltage...

  2. Intrusive images and voluntary memory for affective pictures: contextualization and dual-task interference.

    PubMed

    Krans, Julie; Langner, Oliver; Reinecke, Andrea; Pearson, David G

    2013-12-01

    The present study addressed the role of context information and dual-task interference during the encoding of negative pictures on intrusion development and voluntary recall. Healthy participants were shown negative pictures with or without context information. Pictures were either viewed alone or concurrently with a visuospatial or verbal task. Participants reported their intrusive images of the pictures in a diary. At follow-up, perceptual and contextual memory was tested. Participants in the context group reported more intrusive images and perceptual voluntary memory than participants in the no context group. No effects of the concurrent tasks were found on intrusive image frequency, but perceptual and contextual memory was affected according to the cognitive load of the task. The analogue method cannot be generalized to real-life trauma and the secondary tasks may differ in cognitive load. The findings challenge a dual memory model of PTSD but support an account in which retrieval strategy, rather than encoding processes, accounts for the experience of involuntary versus voluntary recall. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. [Dual pathology].

    PubMed

    Rougier, A

    2008-05-01

    Dual pathology is defined as the association of two potentially epileptogenic lesions, hippocampal (sclerosis, neuronal loss) and extrahippocampal (temporal or extratemporal). Epileptic activity may be generated by either lesion and the relative importance of every lesion's epileptogenicity conditions the surgical strategy adopted. Most frequently associated with hippocampal sclerosis are cortical dysplasias. The common physiopathology of the two lesions is not clearly established. Extrahippocampal lesions may be undetectable on MRI (microdysgenesis, for example) and ictal discharge patterns may vary among dual pathology patients. The surgical strategy depends on the location of the extrahippocampal lesion and its relative role in seizure generation; however, reported surgical results suggest that simultaneous resection of mesial temporal structures along with the extrahippocampal lesion should be performed.

  4. Switchable dual-wavelength single-longitudinal-mode erbium fiber laser utilizing a dual-ring scheme with a saturable absorber

    NASA Astrophysics Data System (ADS)

    Yang, Zi-Qing; Huang, Tzu-Jung; Chang, Yao-Jen; Yeh, Chien-Hung; Chow, Chi-Wai; Chen, Jing-Heng; Chen, Kun-Huang

    2018-06-01

    In this work, we propose and demonstrate a switchable dual-wavelength erbium-doped fiber (EDF) ring laser with stable single-longitudinal-mode (SLM) output. Here, a dual-ring (DR) structure with an unpumped EDF of 2 m is designed to achieve SLM oscillation. Five fiber Bragg gratings (FBGs) are applied in the laser cavity serving as the reflective element to generate different dual-wavelength outputs. In the measurement, six sets of generated dual-wavelengths with various mode-spacing (Δλ) can be achieved via the five FBGs. Additionally, the stability performance of the proposed EDF DR laser is also demonstrated.

  5. Unraveling Executive Functioning in Dual Diagnosis.

    PubMed

    Duijkers, Judith C L M; Vissers, Constance Th W M; Egger, Jos I M

    2016-01-01

    In mental health, the term dual-diagnosis is used for the co-occurrence of Substance Use Disorder (SUD) with another mental disorder. These co-occurring disorders can have a shared cause, and can cause/intensify each other's expression. Forming a threat to health and society, dual-diagnosis is associated with relapses in addiction-related behavior and a destructive lifestyle. This is due to a persistent failure to control impulses and the maintaining of inadequate self-regulatory behavior in daily life. Thus, several aspects of executive functioning like inhibitory, shifting and updating processes seem impaired in dual-diagnosis. Executive (dys-)function is currently even seen as a shared underlying key component of most mental disorders. However, the number of studies on diverse aspects of executive functioning in dual-diagnosis is limited. In the present review, a systematic overview of various aspects of executive functioning in dual-diagnosis is presented, striving for a prototypical profile of patients with dual-diagnosis. Looking at empirical results, inhibitory and shifting processes appear to be impaired for SUD combined with schizophrenia, bipolar disorder or cluster B personality disorders. Studies involving updating process tasks for dual-diagnosis were limited. More research that zooms in to the full diversity of these executive functions is needed in order to strengthen these findings. Detailed insight in the profile of strengths and weaknesses that underlies one's behavior and is related to diagnostic classifications, can lead to tailor-made assessment and indications for treatment, pointing out which aspects need attention and/or training in one's self-regulative abilities.

  6. Data sharing and dual-use issues.

    PubMed

    Bezuidenhout, Louise

    2013-03-01

    The concept of dual-use encapsulates the potential for well-intentioned, beneficial scientific research to also be misused by a third party for malicious ends. The concept of dual-use challenges scientists to look beyond the immediate outcomes of their research and to develop an awareness of possible future (mis)uses of scientific research. Since 2001 much attention has been paid to the possible need to regulate the dual-use potential of the life sciences. Regulation initiatives fall under two broad categories-those that develop the ethical education of scientists and foster an awareness and responsibility of dual-use issues, and those which assess the regulation of information being generated by current research. Both types of initiatives are premised on a cautious, risk-adverse philosophy which advocates careful examination of all future endpoints of research endeavors. This caution advocated within initiatives such as pre-publication review of journal articles contrasts to the obligation to share underpinning data sharing discussions. As the dual-use debate has yet to make a significant impact on data sharing discussions (and vice versa) it is possible that these two areas of knowledge control may present areas of ethical conflict for scientists, and thus need to be more closely examined. This paper examines the tension between the obligation to share exemplified by data sharing principles and the concerns raised by the risk-cautious culture of the dual-use debates. The paper concludes by reflecting on the issues of responsibility as raised by dual-use as relating to data sharing, such as the chain of custody for shared data.

  7. Dual-scanning optical coherence elastography for rapid imaging of two tissue volumes (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Fang, Qi; Frewer, Luke; Wijesinghe, Philip; Hamzah, Juliana; Ganss, Ruth; Allen, Wes M.; Sampson, David D.; Curatolo, Andrea; Kennedy, Brendan F.

    2017-02-01

    In many applications of optical coherence elastography (OCE), it is necessary to rapidly acquire images in vivo, or within intraoperative timeframes, over fields-of-view far greater than can be achieved in one OCT image acquisition. For example, tumour margin assessment in breast cancer requires acquisition over linear dimensions of 4-5 centimetres in under 20 minutes. However, the majority of existing techniques are not compatible with these requirements, which may present a hurdle to the effective translation of OCE. To increase throughput, we have designed and developed an OCE system that simultaneously captures two 3D elastograms from opposite sides of a sample. The optical system comprises two interferometers: a common-path interferometer on one side of the sample and a dual-arm interferometer on the other side. This optical system is combined with scanning mechanisms and compression loading techniques to realize dual-scanning OCE. The optical signals scattered from two volumes are simultaneously detected on a single spectrometer by depth-encoding the interference signal from each interferometer. To demonstrate dual-scanning OCE, we performed measurements on tissue-mimicking phantoms containing rigid inclusions and freshly isolated samples of murine hepatocellular carcinoma, highlighting the use of this technique to visualise 3D tumour stiffness. These findings indicate that our technique holds promise for in vivo and intraoperative applications.

  8. 14 CFR 23.399 - Dual control system.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Dual control system. 23.399 Section 23.399 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... Loads § 23.399 Dual control system. (a) Each dual control system must be designed to withstand the force...

  9. 14 CFR 23.399 - Dual control system.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Dual control system. 23.399 Section 23.399 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... Loads § 23.399 Dual control system. (a) Each dual control system must be designed to withstand the force...

  10. 14 CFR 23.399 - Dual control system.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Dual control system. 23.399 Section 23.399 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... Loads § 23.399 Dual control system. (a) Each dual control system must be designed to withstand the force...

  11. 14 CFR 23.399 - Dual control system.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Dual control system. 23.399 Section 23.399 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... Loads § 23.399 Dual control system. (a) Each dual control system must be designed to withstand the force...

  12. 14 CFR 23.399 - Dual control system.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Dual control system. 23.399 Section 23.399 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... Loads § 23.399 Dual control system. (a) Each dual control system must be designed to withstand the force...

  13. 46 CFR 183.324 - Dual voltage generators.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Dual voltage generators. 183.324 Section 183.324... TONS) ELECTRICAL INSTALLATION Power Sources and Distribution Systems § 183.324 Dual voltage generators. (a) A dual voltage generator installed on a vessel shall be of the grounded type, where: (1) The...

  14. Dual Kidney Allocation Score: A Novel Algorithm Utilizing Expanded Donor Criteria for the Allocation of Dual Kidneys in Adults.

    PubMed

    Johnson, Adam P; Price, Thea P; Lieby, Benjamin; Doria, Cataldo

    2016-09-08

    BACKGROUND Dual kidney transplantation (DKT) of expanded-criteria donors is a cost-intensive procedure that aims to increase the pool of available deceased organ donors and has demonstrated equivalent outcomes to expanded-criteria single kidney transplantation (eSKT). The objective of this study was to develop an allocation score based on predicted graft survival from historical dual and single kidney donors. MATERIAL AND METHODS We analyzed United Network for Organ Sharing (UNOS) data for 1547 DKT and 26 381 eSKT performed between January 1994 and September 2013. We utilized multivariable Cox regression to identify variables independently associated with graft survival in dual and single kidney transplantations. We then derived a weighted multivariable product score from calculated hazard ratios to model the benefit of transplantation as dual kidneys. RESULTS Of 36 donor variables known at the time of listing, 13 were significantly associated with graft survival. The derived dual allocation score demonstrated good internal validity with strong correlation to improved survival in dual kidney transplants. Donors with scores less than 2.1 transplanted as dual kidneys had a worsened median survival of 594 days (24%, p-value 0.031) and donors with scores greater than 3.9 had improved median survival of 1107 days (71%, p-value 0.002). There were 17 733 eSKT (67%) and 1051 DKT (67%) with scores in between these values and no differences in survival (p-values 0.676 and 0.185). CONCLUSIONS We have derived a dual kidney allocation score (DKAS) with good internal validity. Future prospective studies will be required to demonstrate external validity, but this score may help to standardize organ allocation for dual kidney transplantation.

  15. Dual Treatments as Starting Point for Integrative Perceptions in Teaching Mathematics

    ERIC Educational Resources Information Center

    Kërënxhi, Svjetllana; Gjoci, Pranvera

    2015-01-01

    In this paper, we recommend mathematical teaching through dual treatments. The dual treatments notion, classified in dual interpretations, dual analyses, dual solutions, and dual formulations, is explained through concrete examples taken from mathematical textbooks of elementary education. Dual treatments provide opportunities for creating…

  16. Dual Coding, Reasoning and Fallacies.

    ERIC Educational Resources Information Center

    Hample, Dale

    1982-01-01

    Develops the theory that a fallacy is not a comparison of a rhetorical text to a set of definitions but a comparison of one person's cognition with another's. Reviews Paivio's dual coding theory, relates nonverbal coding to reasoning processes, and generates a limited fallacy theory based on dual coding theory. (PD)

  17. Governance of dual-use research: an ethical dilemma

    PubMed Central

    2009-01-01

    Abstract Scenarios where the results of well-intentioned scientific research can be used for both good and harmful purposes give rise to what is now widely known as the “dual-use dilemma”. There has been growing debate about the dual-use nature of life science research with implications for making biological weapons. This paper reviews several controversial publications that have been the focus of debates about dual-use life science research and critically examines relevant policy developments, particularly in the United States of America. Though the dual-use dilemma is inherently ethical in nature, the majority of debates about dual-use research have primarily involved science and security experts rather than ethicists. It is important that there is more ethical input into debates about the governance of dual-use research. PMID:19784453

  18. Intercomparison of Desert Dust Optical Depth from Satellite Measurements

    NASA Technical Reports Server (NTRS)

    Carboni, E.; Thomas, G. E.; Sayer, A. M.; Siddans, R.; Poulsen, C. A.; Grainger, R. G.; Ahn, C.; Antoine, D.; Bevan, S.; Braak, R.; hide

    2012-01-01

    This work provides a comparison of satellite retrievals of Saharan desert dust aerosol optical depth (AOD) during a strong dust event through March 2006. In this event, a large dust plume was transported over desert, vegetated, and ocean surfaces. The aim is to identify the differences between current datasets. The satellite instruments considered are AATSR, AIRS, MERIS, MISR, MODIS, OMI, POLDER, and SEVIRI. An interesting aspect is that the different algorithms make use of different instrument characteristics to obtain retrievals over bright surfaces. These include multi-angle approaches (MISR, AATSR), polarisation measurements (POLDER), single-view approaches using solar wavelengths (OMI, MODIS), and the thermal infrared spectral region (SEVIRI, AIRS). Differences between instruments, together with the comparison of different retrieval algorithms applied to measurements from the same instrument, provide a unique insight into the performance and characteristics of the various techniques employed. As well as the intercomparison between different satellite products, the AODs have also been compared to co-located AERONET data. Despite the fact that the agreement between satellite and AERONET AODs is reasonably good for all of the datasets, there are significant differences between them when compared to each other, especially over land. These differences are partially due to differences in the algorithms, such as assumptions about aerosol model and surface properties. However, in this comparison of spatially and temporally averaged data, it is important to note that differences in sampling, related to the actual footprint of each instrument on the heterogeneous aerosol field, cloud identification and the quality control flags of each dataset can be an important issue.

  19. Dual wavelength imaging of a scrape-off layer in an advanced beam-driven field-reversed configuration

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Osin, D.; Schindler, T., E-mail: dosin@trialphaenergy.com

    2016-11-15

    A dual wavelength imaging system has been developed and installed on C-2U to capture 2D images of a He jet in the Scrape-Off Layer (SOL) of an advanced beam-driven Field-Reversed Configuration (FRC) plasma. The system was designed to optically split two identical images and pass them through 1 nm FWHM filters. Dual wavelength images are focused adjacent on a large format CCD chip and recorded simultaneously with a time resolution down to 10 μs using a gated micro-channel plate. The relatively compact optical system images a 10 cm plasma region with a spatial resolution of 0.2 cm and can bemore » used in a harsh environment with high electro-magnetic noise and high magnetic field. The dual wavelength imaging system provides 2D images of either electron density or temperature by observing spectral line pairs emitted by He jet atoms in the SOL. A large field of view, combined with good space and time resolution of the imaging system, allows visualization of macro-flows in the SOL. First 2D images of the electron density and temperature observed in the SOL of the C-2U FRC are presented.« less

  20. Ocean View

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Analytical Spectral Devices was able to commercialize the "engine" of SeaSpec. The Dual CCD developed for SeaSpec is used in our FieldSpecO Dual UV/VNIR/CCD. This product is very popular for coastal research. It allows for a small suitcase sized spectrometer to be placed in a boat and the attached fiber optic cable can be lowered 30 feet below the surface allowing researchers to perform the same studies as SeaSpec just not at the deep-water depths. Most of the people who inquire about SeaSpec end up purchasing a FieldSpec Dual CCD.SeaSpec was designed to withstand harsh marine environments and depths up to 200 m. While it meets these requirements it is the only instrument of its kind and we consider it a prototype. The first version was released in April 1997. It was tested, we made modification and returned the product in March 1998.

  1. Are factors related to dual-task performance in people with Parkinson's disease dependent on the type of dual task?

    PubMed

    Strouwen, Carolien; Molenaar, Esther A L M; Keus, Samyra H J; Münks, Liesbeth; Heremans, Elke; Vandenberghe, Wim; Bloem, Bastiaan R; Nieuwboer, Alice

    2016-02-01

    Impaired dual-task performance significantly impacts upon functional mobility in people with Parkinson's disease (PD). The aim of this study was to identify determinants of dual-task performance in people with PD in three different dual tasks to assess their possible task-dependency. We recruited 121 home-dwelling patients with PD (mean age 65.93 years; mean disease duration 8.67 years) whom we subjected to regular walking (control condition) and to three dual-task conditions: walking combined with a backwards Digit Span task, an auditory Stroop task and a Mobile Phone task. We measured dual-task gait velocity using the GAITRite mat and dual-task reaction times and errors on the concurrent tasks as outcomes. Motor, cognitive and descriptive variables which correlated to dual-task performance (p < 0.20) were entered into a stepwise forward multiple linear regression model. Single-task gait velocity and executive function, tested by the alternating intake test, was significantly associated with gait velocity during the Digit Span (R(2) = 0.65; p < 0.001), the Stroop (R(2) = 0.73; p < 0.001) and the Mobile Phone task (R(2) = 0.62; p < 0.001). In addition, disease severity proved correlated to gait velocity during the Stroop task. Age was a surplus determinant of gait velocity while using a mobile phone. Single-task gait velocity and executive function as measured by a verbal fluency switching task were independent determinants of dual-task gait performance in people with PD. In contrast to expectation, these factors were the same across different tasks, supporting the robustness of the findings. Future study needs to determine whether these factors predict dual-task abnormalities prospectively. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Structure, function and translational relevance of aquaporin dual water and ion channels.

    PubMed

    Yool, Andrea J; Campbell, Ewan M

    2012-01-01

    Aquaporins have been assumed to be selective for water alone, and aquaglyceroporins are accepted as carrying water and small uncharged solutes including glycerol. This review presents an expanded view of aquaporins as channels with more complex mechanisms of regulation and diverse repertoires of substrate permeabilities than were originally appreciated in the early establishment of the field. The role of aquaporins as dual water and gated ion channels is likely to have physiological and potentially translational relevance, and can be evaluated with newly developed molecular and pharmacological tools. Ion channel activity has been shown for Aquaporins -0, -1, and -6, Drosphila Big Brain, and plant Nodulin-26. Although the concept of ion channel function in aquaporins remains controversial, research advances are beginning to define not only the ion channel function but also the detailed molecular mechanisms that govern and mediate the multifunctional capabilities. With regard to physiological relevance, the adaptive benefit of expression of ion channel activity in aquaporins, implied by amino acid sequence conservation of the ion channel gating domains, suggests they provide more than water or glycerol and solute transport. Dual ion and water channels are of interest for understanding the modulation of transmembrane fluid gradients, volume regulation, and possible signal transduction in tissues expressing classes of aquaporins that have the dual function capability. Other aquaporin classes might be found in future work to have ion channel activities, pending identification of the possible signaling pathways that could govern activation. Copyright © 2012 Elsevier Ltd. All rights reserved.

  3. Dual use research: investigation across multiple science disciplines.

    PubMed

    Oltmann, Shannon

    2015-04-01

    Most recent studies of dual use research have focused on the life sciences, although some researchers have suggested that dual use research occurs across many disciplines. This research is an initial investigation into the prevalence of dual use research in other scientific disciplines by surveying senior editors of scientific journals, drawn from Journal Citation Reports. The survey was emailed to 7,500 journal editors with a response rate of 10.1 %. Approximately 4.8 % of life science editors reported they had to consider whether to publish dual use research and 38.9 % said they decided to not publish the research in question. In disciplines other than the life sciences, 7.2 % of editors from other science disciplines reported that they had to consider whether to publish dual use research, and 48.4 % declined to publish it. The survey investigated relationships between dual use and the journal's source of funding and place of publication, but no relationships were found. Further research is needed to better understand the occurrence of dual use research in other science disciplines.

  4. Volcanic Ash Retrievals Using ORAC and Satellite Measurements in the Visible and IR

    NASA Astrophysics Data System (ADS)

    Mcgarragh, Gregory R.; Thomas, Gareth E.; Povey, Adam C.; Poulsen, Caroline A.; Grainger, Roy G.

    2015-11-01

    The Optimal Retrieval of Aerosol and Cloud (ORAC) is a generalized optimal estimation system that uses visible to infrared measurements from a wide range of instruments including AATSR, AVHRR, MODIS and SEVIRI. Recently, support to retrieve volcanic ash has been added for which it retrieves optical thickness, effective radius and cloud top pressure. In this proceeding we discuss the implementation of the volcanic ash retrieval in ORAC including the retrieval methodology, forward model, sources of uncertainty and the discrimination of ash from aerosol and cloud. Results are presented that are consistent with a well know eruption from both AATSR and MODIS while results of a full SEVIRI retrieval of ash, aerosol and cloud properties relative to the ash is are discussed.

  5. Dual Credit Instructor and Counselor Opinions Concerning the Effectiveness of Dual Credit Programs on Post-Secondary Readiness in Southwest Missouri

    ERIC Educational Resources Information Center

    Cook, Natalie Gail

    2017-01-01

    Dual enrollment numbers continue to increase in public school districts; therefore, dual credit programs must be effective for students, adequately challenging them academically and preparing them for the college environment (Flores, 2014). The intention of this study was to survey dual credit instructors and counselors to determine their opinions…

  6. Dual deep modeling: multi-level modeling with dual potencies and its formalization in F-Logic.

    PubMed

    Neumayr, Bernd; Schuetz, Christoph G; Jeusfeld, Manfred A; Schrefl, Michael

    2018-01-01

    An enterprise database contains a global, integrated, and consistent representation of a company's data. Multi-level modeling facilitates the definition and maintenance of such an integrated conceptual data model in a dynamic environment of changing data requirements of diverse applications. Multi-level models transcend the traditional separation of class and object with clabjects as the central modeling primitive, which allows for a more flexible and natural representation of many real-world use cases. In deep instantiation, the number of instantiation levels of a clabject or property is indicated by a single potency. Dual deep modeling (DDM) differentiates between source potency and target potency of a property or association and supports the flexible instantiation and refinement of the property by statements connecting clabjects at different modeling levels. DDM comes with multiple generalization of clabjects, subsetting/specialization of properties, and multi-level cardinality constraints. Examples are presented using a UML-style notation for DDM together with UML class and object diagrams for the representation of two-level user views derived from the multi-level model. Syntax and semantics of DDM are formalized and implemented in F-Logic, supporting the modeler with integrity checks and rich query facilities.

  7. The dual economy in long-run development

    PubMed Central

    2013-01-01

    A salient feature of developing economies is the coexistence of a modern commercial sector alongside a traditional subsistence sector—the dual economy. The apparent differences in productivity between sectors imply substantial losses in aggregate productivity. Existing theories of the dual economy rely on exogenous price distortions, and cannot explain why or if these distortions evolve over the course of development. This paper provides a model of the dual economy in which the productivity differences arise endogenously because of a non-separability between the value of market and non-market time in the traditional sector. Incorporating endogenous fertility, the model then demonstrates how a dual economy will originate, persist, and eventually disappear within a unified growth framework. An implication is that traditional sector productivity growth will exacerbate the inefficiencies of a dual economy and produce slower overall growth than will modern sector productivity improvements. PMID:23946556

  8. Dual microcather-dual detachable coil technique in embolization for a congenital intrahepatic portosystemic venous shunt (IPSVS).

    PubMed

    Suzuki, Kazushi; Shimohira, Masashi; Hashizume, Takuya; Suzuki, Yosuke; Shibamoto, Yuta

    2013-09-01

    We report a 14-year-old boy with a large intrahepatic portosystemic venous shunt. The shunt seemed to be difficult to coil embolize because it was so large and short. However, it was successfully treated by coil embolization with a new dual microcatheter-dual detachable coil technique.

  9. Discrete-continuous variable structural synthesis using dual methods

    NASA Technical Reports Server (NTRS)

    Schmit, L. A.; Fleury, C.

    1980-01-01

    Approximation concepts and dual methods are extended to solve structural synthesis problems involving a mix of discrete and continuous sizing type of design variables. Pure discrete and pure continuous variable problems can be handled as special cases. The basic mathematical programming statement of the structural synthesis problem is converted into a sequence of explicit approximate primal problems of separable form. These problems are solved by constructing continuous explicit dual functions, which are maximized subject to simple nonnegativity constraints on the dual variables. A newly devised gradient projection type of algorithm called DUAL 1, which includes special features for handling dual function gradient discontinuities that arise from the discrete primal variables, is used to find the solution of each dual problem. Computational implementation is accomplished by incorporating the DUAL 1 algorithm into the ACCESS 3 program as a new optimizer option. The power of the method set forth is demonstrated by presenting numerical results for several example problems, including a pure discrete variable treatment of a metallic swept wing and a mixed discrete-continuous variable solution for a thin delta wing with fiber composite skins.

  10. Dual multispectral and 3D structured light laparoscope

    NASA Astrophysics Data System (ADS)

    Clancy, Neil T.; Lin, Jianyu; Arya, Shobhit; Hanna, George B.; Elson, Daniel S.

    2015-03-01

    Intraoperative feedback on tissue function, such as blood volume and oxygenation would be useful to the surgeon in cases where current clinical practice relies on subjective measures, such as identification of ischaemic bowel or tissue viability during anastomosis formation. Also, tissue surface profiling may be used to detect and identify certain pathologies, as well as diagnosing aspects of tissue health such as gut motility. In this paper a dual modality laparoscopic system is presented that combines multispectral reflectance and 3D surface imaging. White light illumination from a xenon source is detected by a laparoscope-mounted fast filter wheel camera to assemble a multispectral image (MSI) cube. Surface shape is then calculated using a spectrally-encoded structured light (SL) pattern detected by the same camera and triangulated using an active stereo technique. Images of porcine small bowel were acquired during open surgery. Tissue reflectance spectra were acquired and blood volume was calculated at each spatial pixel across the bowel wall and mesentery. SL features were segmented and identified using a `normalised cut' algoritm and the colour vector of each spot. Using the 3D geometry defined by the camera coordinate system the multispectral data could be overlaid onto the surface mesh. Dual MSI and SL imaging has the potential to provide augmented views to the surgeon supplying diagnostic information related to blood supply health and organ function. Future work on this system will include filter optimisation to reduce noise in tissue optical property measurement, and minimise spot identification errors in the SL pattern.

  11. Faculty-Student Dual Relationships: Implications for Counselor Educators

    ERIC Educational Resources Information Center

    Jackson, James L.

    2007-01-01

    This article considers dual relationships between faculty and students from an ethical perspective. A review of the literature focuses on the potential impact of dual relationships on students, faculty, academic institutions, and the consumers students will ultimately serve. Models promoting ethical dual relationships are identified and strategies…

  12. Microresonator soliton dual-comb spectroscopy

    NASA Astrophysics Data System (ADS)

    Suh, Myoung-Gyun; Yang, Qi-Fan; Yang, Ki Youl; Yi, Xu; Vahala, Kerry J.

    2016-11-01

    Measurement of optical and vibrational spectra with high resolution provides a way to identify chemical species in cluttered environments and is of general importance in many fields. Dual-comb spectroscopy has emerged as a powerful approach for acquiring nearly instantaneous Raman and optical spectra with unprecedented resolution. Spectra are generated directly in the electrical domain, without the need for bulky mechanical spectrometers. We demonstrate a miniature soliton-based dual-comb system that can potentially transfer the approach to a chip platform. These devices achieve high-coherence pulsed mode locking. They also feature broad, reproducible spectral envelopes, an essential feature for dual-comb spectroscopy. Our work shows the potential for integrated spectroscopy with high signal-to-noise ratios and fast acquisition rates.

  13. Dual adaptive control: Design principles and applications

    NASA Technical Reports Server (NTRS)

    Mookerjee, Purusottam

    1988-01-01

    The design of an actively adaptive dual controller based on an approximation of the stochastic dynamic programming equation for a multi-step horizon is presented. A dual controller that can enhance identification of the system while controlling it at the same time is derived for multi-dimensional problems. This dual controller uses sensitivity functions of the expected future cost with respect to the parameter uncertainties. A passively adaptive cautious controller and the actively adaptive dual controller are examined. In many instances, the cautious controller is seen to turn off while the latter avoids the turn-off of the control and the slow convergence of the parameter estimates, characteristic of the cautious controller. The algorithms have been applied to a multi-variable static model which represents a simplified linear version of the relationship between the vibration output and the higher harmonic control input for a helicopter. Monte Carlo comparisons based on parametric and nonparametric statistical analysis indicate the superiority of the dual controller over the baseline controller.

  14. Dual Nozzle Aerodynamic and Cooling Analysis Study.

    DTIC Science & Technology

    1981-02-27

    program and to the aerodynamic model computer program. This pro - cedure was used to define two secondary nozzle contours for the baseline con - figuration...both the dual-throat and dual-expander con - cepts. Advanced analytical techniques were utilized to provide quantitative estimates of the bleed flow...preliminary heat transfer analysis of both con - cepts, and (5) engineering analysis of data from the NASA/MSFC hot-fire testing of a dual-throat

  15. Adaptive sampling dual terahertz comb spectroscopy using dual free-running femtosecond lasers.

    PubMed

    Yasui, Takeshi; Ichikawa, Ryuji; Hsieh, Yi-Da; Hayashi, Kenta; Cahyadi, Harsono; Hindle, Francis; Sakaguchi, Yoshiyuki; Iwata, Tetsuo; Mizutani, Yasuhiro; Yamamoto, Hirotsugu; Minoshima, Kaoru; Inaba, Hajime

    2015-06-02

    Terahertz (THz) dual comb spectroscopy (DCS) is a promising method for high-accuracy, high-resolution, broadband THz spectroscopy because the mode-resolved THz comb spectrum includes both broadband THz radiation and narrow-line CW-THz radiation characteristics. In addition, all frequency modes of a THz comb can be phase-locked to a microwave frequency standard, providing excellent traceability. However, the need for stabilization of dual femtosecond lasers has often hindered its wide use. To overcome this limitation, here we have demonstrated adaptive-sampling THz-DCS, allowing the use of free-running femtosecond lasers. To correct the fluctuation of the time and frequency scales caused by the laser timing jitter, an adaptive sampling clock is generated by dual THz-comb-referenced spectrum analysers and is used for a timing clock signal in a data acquisition board. The results not only indicated the successful implementation of THz-DCS with free-running lasers but also showed that this configuration outperforms standard THz-DCS with stabilized lasers due to the slight jitter remained in the stabilized lasers.

  16. Adaptive sampling dual terahertz comb spectroscopy using dual free-running femtosecond lasers

    PubMed Central

    Yasui, Takeshi; Ichikawa, Ryuji; Hsieh, Yi-Da; Hayashi, Kenta; Cahyadi, Harsono; Hindle, Francis; Sakaguchi, Yoshiyuki; Iwata, Tetsuo; Mizutani, Yasuhiro; Yamamoto, Hirotsugu; Minoshima, Kaoru; Inaba, Hajime

    2015-01-01

    Terahertz (THz) dual comb spectroscopy (DCS) is a promising method for high-accuracy, high-resolution, broadband THz spectroscopy because the mode-resolved THz comb spectrum includes both broadband THz radiation and narrow-line CW-THz radiation characteristics. In addition, all frequency modes of a THz comb can be phase-locked to a microwave frequency standard, providing excellent traceability. However, the need for stabilization of dual femtosecond lasers has often hindered its wide use. To overcome this limitation, here we have demonstrated adaptive-sampling THz-DCS, allowing the use of free-running femtosecond lasers. To correct the fluctuation of the time and frequency scales caused by the laser timing jitter, an adaptive sampling clock is generated by dual THz-comb-referenced spectrum analysers and is used for a timing clock signal in a data acquisition board. The results not only indicated the successful implementation of THz-DCS with free-running lasers but also showed that this configuration outperforms standard THz-DCS with stabilized lasers due to the slight jitter remained in the stabilized lasers. PMID:26035687

  17. 20 CFR 226.12 - Employee vested dual benefit.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 1 2011-04-01 2011-04-01 false Employee vested dual benefit. 226.12 Section 226.12 Employees' Benefits RAILROAD RETIREMENT BOARD REGULATIONS UNDER THE RAILROAD RETIREMENT ACT... vested dual benefit. (a) General. An employee vested dual benefit is payable, in addition to tiers I and...

  18. 20 CFR 226.12 - Employee vested dual benefit.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 1 2013-04-01 2012-04-01 true Employee vested dual benefit. 226.12 Section 226.12 Employees' Benefits RAILROAD RETIREMENT BOARD REGULATIONS UNDER THE RAILROAD RETIREMENT ACT... vested dual benefit. (a) General. An employee vested dual benefit is payable, in addition to tiers I and...

  19. 20 CFR 226.12 - Employee vested dual benefit.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 1 2012-04-01 2012-04-01 false Employee vested dual benefit. 226.12 Section 226.12 Employees' Benefits RAILROAD RETIREMENT BOARD REGULATIONS UNDER THE RAILROAD RETIREMENT ACT... vested dual benefit. (a) General. An employee vested dual benefit is payable, in addition to tiers I and...

  20. Generalized Hodge dual for torsion in teleparallel gravity

    NASA Astrophysics Data System (ADS)

    Huang, Peng; Yuan, Fang-Fang

    2016-07-01

    For teleparallel gravity in four dimensions, Lucas and Pereira have shown that its action can be constructed via a generalized Hodge dual for torsion tensor. In this paper, we demonstrate that a direct generalization of this approach to other dimensions fails due to the fact that no generalized Hodge dual operator could be given in general dimensions. Furthermore, if one enforces the definition of a generalized Hodge dual to be consistent with the action of teleparallel gravity in general dimensions, the basic identity for any sensible Hodge dual would require an ad hoc definition for the second Hodge dual operation which is totally unexpected. Therefore, we conclude that at least for the torsion tensor, the observation of Lucas and Pereira only applies to four dimensions.

  1. Oxygen/Alcohol Dual Thrust RCS Engines

    NASA Technical Reports Server (NTRS)

    Angstadt, Tara; Hurlbert, Eric

    1999-01-01

    A non-toxic dual thrust RCS engine offers significant operational, safety, and performance advantages to the space shuttle and the next generation RLVs. In this concept, a single engine produces two thrust levels of 25 and 870 lbf. The low thrust level is provided by the spark torch igniter, which, with the addition of 2 extra valves, can also be made to function as a vernier. A dual thrust RCS engine allows 38 verniers to be packaged more efficiently on a vehicle. These 38 vemiers improve translation and reduce cross coupling, thereby providing more pure roll, pitch, and yaw maneuvers of the vehicle. Compared to the 6 vemiers currently on the shuttle, the 38 dual thrust engines would be 25 to 40% more efficient for the same maneuvers and attitude control. The vernier thrust level also reduces plume impingement and contamination concerns. Redundancy is also improved, thereby improving mission success reliability. Oxygen and ethanol are benign propellants which do not create explosive reaction products or contamination, as compared to hypergolic propellants. These characteristics make dual-thrust engines simpler to implement on a non-toxic reaction control system. Tests at WSTF in August 1999 demonstrated a dual-thrust concept that is successful with oxygen and ethanol. Over a variety of inlet pressures and mixture ratios at 22:1 area ratio, the engine produced between 230 and 297 sec Isp, and thrust levels from 8 lbf. to 50 lbf. This paper describes the benefits of dual-thrust engines and the recent results from tests at WSTF.

  2. Psychosocial approaches to dual diagnosis.

    PubMed

    Drake, R E; Mueser, K T

    2000-01-01

    Recent research elucidates many aspects of the problem of co-occurring substance use disorder (SUD) in patients with severe mental illness, which is often termed dual diagnosis. This paper provides a brief overview of current research on the epidemiology, adverse consequences, and phenomenology of dual diagnosis, followed by a more extensive review of current approaches to services, assessment, and treatment. Accumulating evidence shows that comorbid SUD is quite common among individuals with severe mental illness and that these individuals suffer serious adverse consequences of SUD. The research further suggests that traditional, separate services for individuals with dual disorders are ineffective, and that integrated treatment programs, which combine mental health and substance abuse interventions, offer more promise. In addition to a comprehensive integration of services, successful programs include assessment, assertive case management, motivational interventions for patients who do not recognize the need for substance abuse treatment, behavioral interventions for those who are trying to attain or maintain abstinence, family interventions, housing, rehabilitation, and psychopharmacology. Further research is needed on the organization and financing of dual-diagnosis services and on specific components of the integrated treatment model, such as group treatments, family interventions, and housing approaches.

  3. Dual laser optical system and method for studying fluid flow

    NASA Technical Reports Server (NTRS)

    Owen, R. B.; Witherow, W. K. (Inventor)

    1983-01-01

    A dual laser optical system and method is disclosed for visualization of phenomena in transport substances which induce refractive index gradients such as fluid flow and pressure and temperature gradients in fluids and gases. Two images representing mutually perpendicular components of refractive index gradients may be viewed simultaneously on screen. Two lasers having wave lengths in the visible range but separated by about 1000 angstroms are utilized to provide beams which are collimated into a beam containing components of the different wave lengths. The collimated beam is passed through a test volume of the transparent substance. The collimated beam is then separated into components of the different wave lengths and focused onto a pair of knife edges arranged mutually perpendicular to produce and project images onto the screen.

  4. The locked psychiatric ward: hotel or detention camp for people with dual diagnosis.

    PubMed

    Terkelsen, Toril Borch; Larsen, Inger Beate

    2013-10-01

    The concepts of autonomy and liberty are established goals in mental health care; however, involuntary commitment is used towards people with mental health and substance abuse problems (dual diagnosis). To explore how patients and staff act in the context of involuntary commitment, how interactions are described and how they might be interpreted. Ethnographic methodology in a locked psychiatric ward in Norway. Two parallel images emerged: (a) The ward as a hotel. Several patients wanted a locked ward for rest and safety, even when admission was classified as involuntary. The staff was concerned about using the ward for real treatment of motivated people, rather than merely as a comfortable hotel for the unmotivated. (b) The ward as a detention camp. Other patients found involuntary commitment and restrictions in the ward as a kind of punishment, offending them as individuals. Contrary, the staff understood people with dual diagnoses more like a generalized group in need of their control and care. Patients and staff have different perceptions of involuntary commitment. Based on the patients' points of view, mental health care ought to be characterized by inclusion and recognition, treating patients as equal citizens comparable to guests in a hotel.

  5. Dual wound dc brush motor gearhead

    NASA Technical Reports Server (NTRS)

    Henson, Barrie W.

    1986-01-01

    The design requirements, the design, development tests and problems, the qualification and life test and the findings of the strip examination of a dual wound DC brushed motor gearhead are described. It is the only space qualified dual wound dc brushed motor gearhead in Europe.

  6. 30 CFR 62.140 - Dual hearing protection level.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Dual hearing protection level. 62.140 Section... HEALTH REGULATIONS OCCUPATIONAL NOISE EXPOSURE § 62.140 Dual hearing protection level. If during any work shift a miner's noise exposure exceeds the dual hearing protection level, the mine operator must, in...

  7. 30 CFR 62.140 - Dual hearing protection level.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Dual hearing protection level. 62.140 Section... HEALTH REGULATIONS OCCUPATIONAL NOISE EXPOSURE § 62.140 Dual hearing protection level. If during any work shift a miner's noise exposure exceeds the dual hearing protection level, the mine operator must, in...

  8. Dual infections with different Legionella strains.

    PubMed

    Wewalka, G; Schmid, D; Harrison, T G; Uldum, S A; Lück, C

    2014-01-01

    In 2010 a case of a dual infection with Legionella pneumophila serogroup (sg) 1 and sg 3 was identified by culture of a blood sample collected from a female Austrian patient with septic pneumonia. Subsequently all 35 European National Legionella Reference Laboratories were interviewed regarding the frequency of dual infections in legionellosis. The Reference Laboratories in Denmark, the UK and Germany reported the detection of another 14 cases of dual infections with different Legionella strains between 2002 and 2012. Among the 15 cases, there were four cases with different Legionella species, six cases with different L. pneumophila serogroups, and five cases of dual infections with L. pneumophila sg 1 with different MAb-types. The median age of the 15 cases was 56 years and the male to female ratio 1:1.14. Six of the 15 patients were receiving immunosuppressive treatment following organ transplantation (n = 3) or for underlying haematological and solid malignancies (n = 3). Five of the 15 cases died within 30 days following diagnosis. Efforts to detect dual infections with different Legionella strains will improve our ability to correctly elucidate the causative sources of infection and enhance our understanding of the epidemiology of Legionella infections. © 2013 The Authors Clinical Microbiology and Infection © 2013 European Society of Clinical Microbiology and Infectious Diseases.

  9. Interventions to manage dual practice among health workers.

    PubMed

    Kiwanuka, Suzanne N; Rutebemberwa, Elizeus; Nalwadda, Christine; Okui, Olico; Ssengooba, Freddie; Kinengyere, Alison A; Pariyo, George W

    2011-07-06

    Dual practice, whereby health workers hold two or more jobs, is a common phenomenon globally. In resource constrained low- and middle-income countries dual practice poses an ongoing threat to the efficiency, quality and equity of health services, especially in the public sector. Identifying effective interventions to manage dual practice is important. To assess the effects of regulations implemented to manage dual practice. Databases searched included: The Cochrane Central Register of Controlled Trials (CENTRAL) 2011, Issue 4, part of The Cochrane Library. www.thecochranelibrary.com, including the Cochrane Effective Practice and Organisation of Care (EPOC) Group Specialised Register (searched 26 May 2011); MEDLINE In-Process & Other Non-Indexed Citations May 24, 2011 (searched 26 May 2011); MEDLINE, Ovid (1948 to May week 2 2011) (searched 26 May 2011); EMBASE, Ovid (1980 to 2011 week 20) (searched 26 May 2011); Science Citation Index and Social Sciences Citation Index, ISI Web of Science (1975 to present) (searched 04 December 2009); LILACS (searched January 2010); and AIM (December 2009) (searched 18 December 2009). Randomized controlled trials, non-randomized controlled trials, controlled before-and-after studies and interrupted-time-series studies. Dual practice was defined as holding more than one job. Studies for inclusion were those focusing on interventions to manage dual practice among health professionals employed in the public health sector. Two review authors independently applied the criteria for inclusion and exclusion of studies when scanning the identified titles and abstracts. The same two review authors independently screened full reports of selected citations. At each stage, results were compared and discrepancies settled through discussion. No studies were found which were eligible for inclusion in this review. There is a need to rigorously evaluate the effects of interventions implemented to manage dual practice among health workers. However

  10. [Dual-doctor marriages].

    PubMed

    Gjerberg, Elisabeth

    2003-08-28

    Dual-doctor marriages are increasingly frequent. The question raised here is whether being married to a fellow physician has a different impact on a doctor's career and family life than having a spouse in a different profession. In 1996 a questionnaire was mailed to physicians who received their authorisation to practise medicine in Norway in the years 1980 through 1983 period; 1142 responded (67 %). They supplied data on their current employment status and data on employment history and marital background. Multivariate analysis was used in order to explore how the educational background of spouses affects a medical career. Female physicians who marry a physician marry and have families at a younger age than other female physicians. Moreover, they more often enter specialties; in some specialities they also qualify earlier than those who marry non-physicians. The same did not hold for male physicians. However, male physicians in dual-doctor marriages more frequently worked part time and they far less frequently had spouses working part time than other male doctors. The results suggest that dual-doctor couples to a higher extent share in giving care to their families, have more interests in common and are more supportive of each other's needs. Female physicians seem to benefit particularly.

  11. Dual-Schemata Model

    NASA Astrophysics Data System (ADS)

    Taniguchi, Tadahiro; Sawaragi, Tetsuo

    In this paper, a new machine-learning method, called Dual-Schemata model, is presented. Dual-Schemata model is a kind of self-organizational machine learning methods for an autonomous robot interacting with an unknown dynamical environment. This is based on Piaget's Schema model, that is a classical psychological model to explain memory and cognitive development of human beings. Our Dual-Schemata model is developed as a computational model of Piaget's Schema model, especially focusing on sensori-motor developing period. This developmental process is characterized by a couple of two mutually-interacting dynamics; one is a dynamics formed by assimilation and accommodation, and the other dynamics is formed by equilibration and differentiation. By these dynamics schema system enables an agent to act well in a real world. This schema's differentiation process corresponds to a symbol formation process occurring within an autonomous agent when it interacts with an unknown, dynamically changing environment. Experiment results obtained from an autonomous facial robot in which our model is embedded are presented; an autonomous facial robot becomes able to chase a ball moving in various ways without any rewards nor teaching signals from outside. Moreover, emergence of concepts on the target movements within a robot is shown and discussed in terms of fuzzy logics on set-subset inclusive relationships.

  12. 49 CFR 538.9 - Dual fuel vehicle incentive.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 6 2011-10-01 2011-10-01 false Dual fuel vehicle incentive. 538.9 Section 538.9... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION MANUFACTURING INCENTIVES FOR ALTERNATIVE FUEL VEHICLES § 538.9 Dual fuel vehicle incentive. The application of 49 U.S.C. 32905(b) and (d) to qualifying dual fuel vehicles...

  13. 49 CFR 538.9 - Dual fuel vehicle incentive.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 6 2010-10-01 2010-10-01 false Dual fuel vehicle incentive. 538.9 Section 538.9... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION MANUFACTURING INCENTIVES FOR ALTERNATIVE FUEL VEHICLES § 538.9 Dual fuel vehicle incentive. The application of 49 U.S.C. 32905(b) and (d) to qualifying dual fuel vehicles...

  14. 49 CFR 538.9 - Dual fuel vehicle incentive.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 6 2013-10-01 2013-10-01 false Dual fuel vehicle incentive. 538.9 Section 538.9... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION MANUFACTURING INCENTIVES FOR ALTERNATIVE FUEL VEHICLES § 538.9 Dual fuel vehicle incentive. The application of 49 U.S.C. 32905(b) and (d) to qualifying dual fuel vehicles...

  15. 49 CFR 538.9 - Dual fuel vehicle incentive.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 6 2012-10-01 2012-10-01 false Dual fuel vehicle incentive. 538.9 Section 538.9... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION MANUFACTURING INCENTIVES FOR ALTERNATIVE FUEL VEHICLES § 538.9 Dual fuel vehicle incentive. The application of 49 U.S.C. 32905(b) and (d) to qualifying dual fuel vehicles...

  16. Public health and social work: training dual professionals for the contemporary workplace.

    PubMed

    Ruth, Betty J; Sisco, Sarah; Wyatt, Jamie; Bethke, Christina; Bachman, Sara S; Piper, Tinka Markham

    2008-01-01

    The emergence of new, complex social health concerns demands that the public health field strengthen its capacity to respond. Academic institutions are vital to improving the public health infrastructure. Collaborative and transdisciplinary practice competencies are increasingly viewed as key components of public health training. The social work profession, with its longstanding involvement in public health and emphasis on ecological approaches, has been a partner in many transdisciplinary community-based efforts. The more than 20 dual-degree programs in public health and social work currently offered reflect this collaborative history. This study represents an exploratory effort to evaluate the impact of these programs on the fields of public health and social work. This study explored motivations, perspectives, and experiences of 41 graduates from four master of social work/master of public health (MSW/ MPH) programs. Four focus groups were conducted using traditional qualitative methods during 2004. Findings suggest that MSW/MPH alumni self-selected into dual programs because of their interest in the missions, ethics, and practices of both professions. Participants highlighted the challenges and opportunities of dual professionalism, including the struggle to better define public health social work in the workplace. Implications for academic public health focus on how schools can improve MSW/MPH programs to promote transdisciplinary collaboration. Increased recognition, better coordination, and greater emphasis on marketing to prospective employers were suggested. A national evaluation of MSW/MPH graduates could strengthen the roles and contributions of public health social work to the public health infrastructure. A conceptual framework, potentially based on developmental theory, could guide this evaluation of the MSW/MPH training experience.

  17. A Descriptive Analysis of the Educational Perceptions, Professional Identity, and Professional Practices of Dual-Trained Music Therapists as Counselors.

    PubMed

    Sevcik, Emily E; Jones, Jennifer D; Myers, Charles E

    2017-11-01

    Given the rise in music therapy master's programs that offer dual degrees in music therapy and counseling or programs that satisfy state mental health counseling licensure laws, the professional counseling field is playing an increased role in the advanced education and professional practices of music therapists. To identify factors that lead music therapists to pursue advanced education with an emphasis in professional counseling, perceptions about benefits and drawbacks for three advanced degree options (i.e., music therapy, counseling, and music therapy/counseling dual degree), and describe the professional practices and identity of dual-trained music therapists as counselors. A convenience sample of music therapists (n = 123) who held board certification, and held a master's degree or higher that emphasized professional counseling, completed an online survey. We used descriptive statistics to analyze categorical and numeric survey data. Eligibility for licensure as a professional counselor was the most important decisional factor in selecting a specific master's degree program. Respondents also reported favorable perceptions of the dual degree in music therapy and counseling. With regard to professional practice and identity, respondents reported high use of verbal processing techniques alongside music therapy interventions, and dual-trained music therapists retained their professional identity as a music therapist. The reported view of licensure in a related field as beneficial and frequent use of verbal processing techniques warrants future study into the role of counseling in the advanced training of music therapists. Given contradictory findings across studies, we recommend investigators also explore how a degree in a related field affects career longevity of music therapists. © the American Music Therapy Association 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com

  18. Methods of Attenuation Correction for Dual-Wavelength and Dual-Polarization Weather Radar Data

    NASA Technical Reports Server (NTRS)

    Meneghini, R.; Liao, L.

    2007-01-01

    In writing the integral equations for the median mass diameter and number concentration, or comparable parameters of the raindrop size distribution, it is apparent that the forms of the equations for dual-polarization and dual-wavelength radar data are identical when attenuation effects are included. The differential backscattering and extinction coefficients appear in both sets of equations: for the dual-polarization equations, the differences are taken with respect to polarization at a fixed frequency while for the dual-wavelength equations, the differences are taken with respect to frequency at a fixed polarization. An alternative to the integral equation formulation is that based on the k-Z (attenuation coefficient-radar reflectivity factor) parameterization. This-technique was originally developed for attenuating single-wavelength radars, a variation of which has been applied to the TRMM Precipitation Radar data (PR). Extensions of this method have also been applied to dual-polarization data. In fact, it is not difficult to show that nearly identical equations are applicable as well to dualwavelength radar data. In this case, the equations for median mass diameter and number concentration take the form of coupled, but non-integral equations. Differences between this and the integral equation formulation are a consequence of the different ways in which attenuation correction is performed under the two formulations. For both techniques, the equations can be solved either forward from the radar outward or backward from the final range gate toward the radar. Although the forward-going solutions tend to be unstable as the attenuation out to the range of interest becomes large in some sense, an independent estimate of path attenuation is not required. This is analogous to the case of an attenuating single-wavelength radar where the forward solution to the Hitschfeld-Bordan equation becomes unstable as the attenuation increases. To circumvent this problem, the

  19. Dual Mode Slotted Monopole Antenna

    DTIC Science & Technology

    2017-01-05

    of 15 DUAL MODE SLOTTED MONOPOLE ANTENNA STATEMENT OF GOVERNMENT INTEREST [0001] The invention described herein may be manufactured and used by...to a dual mode antenna having one mode as a slotted cylinder antenna and another mode as a monopole antenna . (2) Description of the Prior Art...0004] Slotted cylinder antennas are popular antennas for use in line of sight communications systems, especially where the carrier frequency exceeds

  20. Unveiling aerosol-cloud interactions - Part 2: Minimising the effects of aerosol swelling and wet scavenging in ECHAM6-HAM2 for comparison to satellite data

    NASA Astrophysics Data System (ADS)

    Neubauer, David; Christensen, Matthew W.; Poulsen, Caroline A.; Lohmann, Ulrike

    2017-11-01

    Aerosol-cloud interactions (ACIs) are uncertain and the estimates of the ACI effective radiative forcing (ERFaci) magnitude show a large variability. Within the Aerosol_cci project the susceptibility of cloud properties to changes in aerosol properties is derived from the high-resolution AATSR (Advanced Along-Track Scanning Radiometer) data set using the Cloud-Aerosol Pairing Algorithm (CAPA) (as described in our companion paper) and compared to susceptibilities from the global aerosol climate model ECHAM6-HAM2 and MODIS-CERES (Moderate Resolution Imaging Spectroradiometer - Clouds and the Earth's Radiant Energy System) data. For ECHAM6-HAM2 the dry aerosol is analysed to mimic the effect of CAPA. Furthermore the analysis is done for different environmental regimes. The aerosol-liquid water path relationship in ECHAM6-HAM2 is systematically stronger than in AATSR-CAPA data and cannot be explained by an overestimation of autoconversion when using diagnostic precipitation but rather by aerosol swelling in regions where humidity is high and clouds are present. When aerosol water is removed from the analysis in ECHAM6-HAM2 the strength of the susceptibilities of liquid water path, cloud droplet number concentration and cloud albedo as well as ERFaci agree much better with those of AATSR-CAPA or MODIS-CERES. When comparing satellite-derived to model-derived susceptibilities, this study finds it more appropriate to use dry aerosol in the computation of model susceptibilities. We further find that the statistical relationships inferred from different satellite sensors (AATSR-CAPA vs. MODIS-CERES) as well as from ECHAM6-HAM2 are not always of the same sign for the tested environmental conditions. In particular the susceptibility of the liquid water path is negative in non-raining scenes for MODIS-CERES but positive for AATSR-CAPA and ECHAM6-HAM2. Feedback processes like cloud-top entrainment that are missing or not well represented in the model are therefore not well

  1. Dual energy CT at the synchrotron: a piglet model for neurovascular research.

    PubMed

    Schültke, Elisabeth; Kelly, Michael E; Nemoz, Christian; Fiedler, Stefan; Ogieglo, Lissa; Crawford, Paul; Paterson, Jessica; Beavis, Cole; Esteve, Francois; Brochard, Thierry; Renier, Michel; Requardt, Herwig; Dallery, Dominique; Le Duc, Geraldine; Meguro, Kotoo

    2011-08-01

    Although the quality of imaging techniques available for neurovascular angiography in the hospital environment has significantly improved over the last decades, the equipment used for clinical work is not always suited for neurovascular research in animal models. We have previously investigated the suitability of synchrotron-based K-edge digital subtraction angiography (KEDSA) after intravenous injection of iodinated contrast agent for neurovascular angiography in radiography mode in both rabbit and pig models. We now have used the KEDSA technique for the acquisition of three-dimensional images and dual energy CT. All experiments were conducted at the biomedical beamline ID 17 of the European Synchrotron Radiation Facility (ESRF). A solid state germanium (Ge) detector was used for the acquisition of image pairs at 33.0 and 33.3 keV. Three-dimensional images were reconstructed from an image series containing 60 single images taken throughout a full rotation of 360°. CT images were reconstructed from two half-acquisitions with 720 projections each. The small detector field of view was a limiting factor in our experiments. Nevertheless, we were able to show that dual energy CT using the KEDSA technique available at ID 17 is suitable for neurovascular research in animal models. Copyright © 2010. Published by Elsevier Ireland Ltd.

  2. Equations of motion of slung load systems with results for dual lift

    NASA Technical Reports Server (NTRS)

    Cicolani, Luigi S.; Kanning, Gerd

    1990-01-01

    General simulation equations are derived for the rigid body motion of slung load systems. These systems are viewed as consisting of several rigid bodies connected by straight-line cables or links. The suspension can be assumed to be elastic or inelastic, both cases being of interest in simulation and control studies. Equations for the general system are obtained via D'Alembert's principle and the introduction of generalized velocity coordinates. Three forms are obtained. Two of these generalize previous case-specific results for single helicopter systems with elastic or inelastic suspensions. The third is a new formulation for inelastic suspensions. It is derived from the elastic suspension equations by choosing the generalized coordinates so as to separate motion due to cable stretching from motion with invariant cable lengths. The result is computationally more efficient than the conventional formulation, and is readily integrated with the elastic suspension formulation and readily applied to the complex dual lift and multilift systems. Equations are derived for dual lift systems. Three proposed suspension arrangements can be integrated in a single equation set. The equations are given in terms of the natural vectors and matrices of three-dimensional rigid body mechanics and are tractable for both analysis and programming.

  3. SU-G-IeP2-15: Virtual Insertion of Digital Kidney Stones Into Dual-Source, Dual- Energy CT Projection Data

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ferrero, A; Chen, B; Huang, A

    Purpose: In order to investigate novel methods to more accurately estimate the mineral composition of kidney stones using dual energy CT, it is desirable to be able to combine digital stones of known composition with actual phantom and patient scan data. In this work, we developed and validated a method to insert digital kidney stones into projection data acquired on a dual-source, dual-energy CT system. Methods: Attenuation properties of stones of different mineral composition were computed using tabulated mass attenuation coefficients, the chemical formula for each stone type, and the effective beam energy at each evaluated tube potential. A previouslymore » developed method to insert lesions into x-ray CT projection data was extended to include simultaneous dual-energy CT projections acquired on a dual-source gantry (Siemens Somatom Flash). Digital stones were forward projected onto both detectors and the resulting projections added to the physically acquired sinogram data. To validate the accuracy of the technique, digital stones were inserted into different locations in the ACR CT accreditation phantom; low and high contrast resolution, CT number accuracy and noise properties were compared before and after stone insertion. The procedure was repeated for two dual-energy tube potential pairs in clinical use on the scanner, 80/Sn140 kV and 100/Sn140 kV, respectively. Results: The images reconstructed after the insertion of digital kidney stones were consistent with the images reconstructed from the scanner. The largest average CT number difference for the 4 insert in the CT number accuracy module of the phantom was 3 HU. Conclusion: A framework was developed and validated for the creation of digital kidney stones of known mineral composition, and their projection-domain insertion into commercial dual-source, dual-energy CT projection data. This will allow a systematic investigation of the impact of scan and reconstruction parameters on stone attenuation and

  4. Method and system for dual resolution translation stage

    DOEpatents

    Halpin, John Michael

    2014-04-22

    A dual resolution translation stage includes a stage assembly operable to receive an optical element and a low resolution adjustment device mechanically coupled to the stage assembly. The dual resolution stage also includes an adjustable pivot block mechanically coupled to the stage assembly. The adjustable pivot block includes a pivot shaft. The dual resolution stage further includes a lever arm mechanically coupled to the adjustable pivot block. The lever arm is operable to pivot about the pivot shaft. The dual resolution stage additionally includes a high resolution adjustment device mechanically coupled to the lever arm and the stage assembly.

  5. Recombinant probiotics with antimicrobial peptides: a dual strategy to improve immune response in immunocompromised patients.

    PubMed

    Mandal, Santi M; Silva, Osmar N; Franco, Octavio L

    2014-08-01

    Bacterial infectious diseases are currently a serious health problem, especially in patients compromised by illness or those receiving immune-suppressant drugs. In this context, it is not only essential to improve the understanding of infectious mechanisms and host response but also to discover novel therapies with extreme urgency. Probiotics and antimicrobial peptides are also favorably viewed as novel strategies in the control of resistant bacteria. The present review will shed some light on the use of probiotic microorganisms expressing antimicrobial peptides as a dual therapy to control bacterial infectious diseases. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Musical expertise has minimal impact on dual task performance.

    PubMed

    Cocchini, Gianna; Filardi, Maria Serena; Crhonkova, Marcela; Halpern, Andrea R

    2017-05-01

    Studies investigating effect of practice on dual task performance have yielded conflicting findings, thus supporting different theoretical accounts about the organisation of attentional resources when tasks are performed simultaneously. Because practice has been proven to reduce the demand of attention for the trained task, the impact of long-lasting training on one task is an ideal way to better understand the mechanisms underlying dual task decline in performance. Our study compared performance during dual task execution in expert musicians compared to controls with little if any musical experience. Participants performed a music recognition task and a visuo-spatial task separately (single task) or simultaneously (dual task). Both groups showed a significant but similar performance decline during dual tasks. In addition, the two groups showed a similar decline of dual task performance during encoding and retrieval of the musical information, mainly attributed to a decline in sensitivity. Our results suggest that attention during dual tasks is similarly distributed by expert and non-experts. These findings are in line with previous studies showing a lack of sensitivity to difficulty and lack of practice effect during dual tasks, supporting the idea that different tasks may rely on different and not-sharable attentional resources.

  7. Dual mode nuclear rocket system applications.

    NASA Technical Reports Server (NTRS)

    Boretz, J. E.; Bell, J. M.; Plebuch, R. K.; Priest, C. C.

    1972-01-01

    Mission areas where the dual-mode nuclear rocket system is superior to nondual-mode systems are demonstrated. It is shown that the dual-mode system is competitive with the nondual-mode system even for those specific missions and particular payload configurations where it does not have a clear-cut advantage.

  8. Departmental Issues in Dual-Academic Marriages.

    ERIC Educational Resources Information Center

    Barbee, Anita P.; Cunningham, Michael R.

    This paper discusses issues pertaining to the recruitment and hiring of dual-career academic couples by universities and psychology departments. Studies have shown that both husbands and wives in dual psychologist couples are more productive in number of publications, paper presentations, and grants awarded than their single counterparts, yet many…

  9. 7 CFR 7.17 - Dual office.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 1 2010-01-01 2010-01-01 false Dual office. 7.17 Section 7.17 Agriculture Office of... STATE, COUNTY AND COMMUNITY COMMITTEES § 7.17 Dual office. (a) County committee membership. A member of... any other county office employee. (b) Community committee membership. A member of the community...

  10. Dual throat engine design for a SSTO launch vehicle

    NASA Technical Reports Server (NTRS)

    Obrien, C. J.; Salmon, J. W.

    1980-01-01

    A propulsion system analysis of a dual fuel, dual throat engine for launch vehicle application was conducted. Basic dual throat engine characterization data are presented to allow vehicle optimization studies to be conducted. A preliminary baseline engine system was defined. Dual throat engine performance, envelope, and weight parametric data were generated over the parametric range of thrust from 890 to 8896 KN (200K to 2M lb-force), chamber pressure from 6.89 million to 34.5 million N/sq m (1000 to 5000 psia) thrust ratio from 1.2 to 5, and a range of mixture ratios for the two tripropellant combinations: LO2/RP-1 + LH2 and LO2/LCH4 + LH2. The results of the study indicate that the dual fuel dual throat engine is a viable single stage to orbit candidate.

  11. Dual-Energy Computed Tomography: Image Acquisition, Processing, and Workflow.

    PubMed

    Megibow, Alec J; Kambadakone, Avinash; Ananthakrishnan, Lakshmi

    2018-07-01

    Dual energy computed tomography has been available for more than 10 years; however, it is currently on the cusp of widespread clinical use. The way dual energy data are acquired and assembled must be appreciated at the clinical level so that the various reconstruction types can extend its diagnostic power. The type of scanner that is present in a given practice dictates the way in which the dual energy data can be presented and used. This article compares and contrasts how dual source, rapid kV switching, and spectral technologies acquire and present dual energy reconstructions to practicing radiologists. Copyright © 2018 Elsevier Inc. All rights reserved.

  12. Dual antiplatelet treatment in patients candidates for abdominal surgery.

    PubMed

    Illuminati, Giulio; Ceccanei, Gianluca; Pacilè, Maria A; Pizzardi, Giulia; Palumbo, Piergaspare; Vietri, Francesco

    2013-01-01

    With the increasing diffusion of percutaneous interventions (PCI), surgeons are often faced with the problem of operating on patients under dual antiplatelet treatment. Replacing dual antiplatelet regiment with low molecular weight heparin may expose to the abrupt thrombosis of coronary stent and massive myocardial infarction. The purpose of this study was to test the hypothesis that abdominal operations can be safely performed under dual antiplatelet treatment. Eleven patients underwent 5 colectomies, 3 nefrectomies, 2 gastrectomies and 1 hysterectomy under aspirin and plavix without any significant perioperative hemorrhage. These preliminary results show that abdominal operations can be safely performed under dual antiplatelet regimen. Abdominal surgery, Dual antiplatelet treatment.

  13. Using dual-domain advective-transport simulation to reconcile multiple-tracer ages and estimate dual-porosity transport parameters

    NASA Astrophysics Data System (ADS)

    Sanford, Ward E.; Niel Plummer, L.; Casile, Gerolamo; Busenberg, Ed; Nelms, David L.; Schlosser, Peter

    2017-06-01

    Dual-domain transport is an alternative conceptual and mathematical paradigm to advection-dispersion for describing the movement of dissolved constituents in groundwater. Here we test the use of a dual-domain algorithm combined with advective pathline tracking to help reconcile environmental tracer concentrations measured in springs within the Shenandoah Valley, USA. The approach also allows for the estimation of the three dual-domain parameters: mobile porosity, immobile porosity, and a domain exchange rate constant. Concentrations of CFC-113, SF6, 3H, and 3He were measured at 28 springs emanating from carbonate rocks. The different tracers give three different mean composite piston-flow ages for all the springs that vary from 5 to 18 years. Here we compare four algorithms that interpret the tracer concentrations in terms of groundwater age: piston flow, old-fraction mixing, advective-flow path modeling, and dual-domain modeling. Whereas the second two algorithms made slight improvements over piston flow at reconciling the disparate piston-flow age estimates, the dual-domain algorithm gave a very marked improvement. Optimal values for the three transport parameters were also obtained, although the immobile porosity value was not well constrained. Parameter correlation and sensitivities were calculated to help quantify the uncertainty. Although some correlation exists between the three parameters being estimated, a watershed simulation of a pollutant breakthrough to a local stream illustrates that the estimated transport parameters can still substantially help to constrain and predict the nature and timing of solute transport. The combined use of multiple environmental tracers with this dual-domain approach could be applicable in a wide variety of fractured-rock settings.

  14. Enhanced broadband near-IR luminescence and gain spectra of bismuth/erbium co-doped fiber by 830 and 980 nm dual pumping

    NASA Astrophysics Data System (ADS)

    Zhao, Qiancheng; Luo, Yanhua; Wang, Wenyu; Canning, John; Peng, Gang-Ding

    2017-04-01

    A dual 830 and 980 nm pumping scheme is proposed aiming at broadening and flattening the spectral performance of bismuth/erbium codoped multicomponent fiber (BEDF). The spectral properties of distinct Bi active centers (BACs) associated with germanium (BAC-Ge), aluminium (BAC-Al), phosphorus (BAC-P) and silicon (BAC-Si) are characterized under single pumping of 830 and 980 nm, respectively. Based on the emission slope efficiencies of BAC-Al (˜1100 nm) and BAC-Si (˜1430 nm) under single pumping of 830 and 980 nm, the dual pumping scheme with the optimal pump power ratio of 25 (980 nm VS 830 nm) is determined to achieve flat, ultrabroadband luminescence spectra covering the wavelength range 950-1600 nm. The dual pumping scheme is further demonstrated on the on-off gain performance of BEDF. It is found under the pump power ratio of ˜8 (980 VS 830 nm), The gain spectrum has been flattened and broadened over 300 nm (1300-1600 nm) with an average gain coefficient of ˜1.5 dBm-1. The spectral coverage is approximately 1.5 and 3 times wider compared to single pumping of 830 and 980 nm pumping, respectively. The energy level diagrams of 830 and 980 nm are also constructed separately in view of the optical characteristic, which further clarifies the advantage for dual pumping. The proposed dual 830 and 980 nm pumping scheme with the multicomponent BEDF shows great potential in various broadband optical applications such as uniform ASE source, broadband amplifier and tuneable laser in NIR band.

  15. Dual frequency comb metrology with one fiber laser

    NASA Astrophysics Data System (ADS)

    Zhao, Xin; Takeshi, Yasui; Zheng, Zheng

    2016-11-01

    Optical metrology techniques based on dual optical frequency combs have emerged as a hotly studied area targeting a wide range of applications from optical spectroscopy to microwave and terahertz frequency measurement. Generating two sets of high-quality comb lines with slightly different comb-tooth spacings with high mutual coherence and stability is the key to most of the dual-comb schemes. The complexity and costs of such laser sources and the associated control systems to lock the two frequency combs hinder the wider adoption of such techniques. Here we demonstrate a very simple and rather different approach to tackle such a challenge. By employing novel laser cavity designs in a mode-locked fiber laser, a simple fiber laser setup could emit dual-comb pulse output with high stability and good coherence between the pulse trains. Based on such lasers, comb-tooth-resolved dual-comb optical spectroscopy is demonstrated. Picometer spectral resolving capability could be realized with a fiber-optic setup and a low-cost data acquisition system and standard algorithms. Besides, the frequency of microwave signals over a large range can be determined based on a simple setup. Our results show the capability of such single-fiber-laser-based dual-comb scheme to reduce the complexity and cost of dual-comb systems with excellent quality for different dual-comb applications.

  16. Dual protection: more needed than practised or understood.

    PubMed

    Berer, Marge

    2006-11-01

    Although non-barrier contraceptive use has become a global norm, unprotected sex in relation to sexually transmitted infections remains the norm almost everywhere. Dual protection is protection from unwanted pregnancy, HIV and other sexually transmitted infections, and is a form of safer sex for heterosexual couples that is more needed than practised or understood. This paper draws on a review of the literature in family planning, obstetrics and gynaecology, and AIDS-related journals from 1998 to early 2005. Definitions of dual protection, found mainly in family planning literature, are very narrow. Condoms remain the mainstay of dual protection, but the aim of this paper is to provide an expanded list of dual protection methods to show that there is a range of options. These include non-penetrative sex and the increasing use of condoms with the back-up of emergency contraception on the part of young people. The fact that people may fail to use dual protection consistently and correctly is not a valid reason not to promote it. It is never too late for those providing family planning and STI/HIV prevention services to start promoting condoms and dual protection. In the long-term, the development of highly efficacious and highly acceptable methods of dual protection is an urgent research priority, starting with a wider range of condoms that will appeal to more people.

  17. Cerebellum and Integration of Neural Networks in Dual-Task Processing

    PubMed Central

    Wu, Tao; Liu, Jun; Hallett, Mark; Zheng, Zheng; Chan, Piu

    2014-01-01

    Performing two tasks simultaneously (dual-task) is common in human daily life. The neural correlates of dual-task processing remain unclear. In the current study, we used a dual motor and counting task with functional MRI (fMRI) to determine whether there are any areas additionally activated for dual-task performance. Moreover, we investigated the functional connectivity of these added activated areas, as well as the training effect on brain activity and connectivity. We found that the right cerebellar vermis, left lobule V of the cerebellar anterior lobe and precuneus are additionally activated for this type of dual-tasking. These cerebellar regions had functional connectivity with extensive motor- and cognitive-related regions. Dual-task training induced less activation in several areas, but increased the functional connectivity between these cerebellar regions and numbers of motor- and cognitive-related areas. Our findings demonstrate that some regions within the cerebellum can be additionally activated with dual-task performance. Their role in dual motor and cognitive task processes is likely to integrate motor and cognitive networks, and may be involved in adjusting these networks to be more efficient in order to perform dual-tasking properly. The connectivity of the precuneus differs from the cerebellar regions. A possible role of the precuneus in dual-task may be monitoring the operation of active brain networks. PMID:23063842

  18. Dual Enrollment as a Liminal Space

    ERIC Educational Resources Information Center

    Hofmann, Eric; Voloch, Daniel

    2012-01-01

    Dual enrollment is a place between high school and college that is neither exclusively one nor the other. Dual enrollment inhabits a space where larger questions about higher education--the cultural practices, norms, institutional relationships and interactions, and the overall "business" of learning--are grappled with on a daily basis. To the…

  19. Support Networks of Dual Career Couples.

    ERIC Educational Resources Information Center

    Lloyd, Sally A.; And Others

    Although social networks play an important role in supporting families under stress, there is some evidence that families living a stressful dual career life style may have limited network resources. To describe support networks of dual career couples and to examine the relationship between the supportiveness of the network and satisfaction with…

  20. Shot H3837: Darht's First Dual-Axis Explosive Experiment

    NASA Astrophysics Data System (ADS)

    Mendez, Jacob; McNeil, Wendy Vogan; Harsh, James; Hull, Lawrence

    2011-06-01

    Test H3837 was the first explosive shot performed in front of both flash x-ray axes at the Los Alamos Dual Axis Radiographic HydroTest (DARHT) facility. Executed in November 2009, the shot was an explosively-driven metal flyer plate in a series of experiments designed to explore equation-of-state properties of shocked materials. Imaging the initial shock wave traveling through the flyer plate, DARHT Axis II captured the range of motion from the shock front emergence in the flyer to breakout at the free surface; the Axis I pulse provided a perpendicular perspective of the shot at a time coinciding with the third pulse of Axis II. Since the days of the Manhattan Project, penetrating radiography with multiple frames from different viewing angles has remained a high-profile goal at the Laboratory. H3837 is merely the beginning of a bright future for two-axis penetrating radiography.

  1. Dual loyalties: Everyday ethical problems of registered nurses and physicians in combat zones.

    PubMed

    Lundberg, Kristina; Kjellström, Sofia; Sandman, Lars

    2017-01-01

    When healthcare personnel take part in military operations in combat zones, they experience ethical problems related to dual loyalties, that is, when they find themselves torn between expectations of doing caring and military tasks, respectively. This article aims to describe how Swedish healthcare personnel reason concerning everyday ethical problems related to dual loyalties between care and military tasks when undertaking healthcare in combat zones. Abductive qualitative design. Participants and research context: Individual interviews with 15 registered nurses and physicians assigned for a military operation in Mali. Ethical considerations: The participants signed up voluntarily, and requirements for informed consent and confidentiality were met. The research was approved by the Regional Ethics Review Board in Gothenburg (D no. 816-14; 24 November 2014). Three main categories emerged: reasons for not undertaking combat duties, reasons for undertaking combat duties and restricted loyalty to military duties, and 14 subcategories. Reasons for not undertaking combat duties were that it was not in their role, not according to ethical codes or humanitarian law or a breach towards patients. Reasons for undertaking combat duties were that humanitarian law does not apply or has to be treated pragmatically or that it is a case of force protection. Shortage of resources and competence were reasons for both doing and not doing military tasks. Under some circumstances, they could imagine undertaking military tasks: when under threat, if unseen or if not needed for healthcare duties. These discrepant views suggest a lack of a common view on what is ethically acceptable or not, and therefore we suggest further normative discussion on how these everyday ethical problems should be interpreted in the light of humanitarian law and ethical codes of healthcare personnel and following this, further training in ethical reflection before going on military operations.

  2. Dual Pathology of Mandible

    PubMed Central

    Rajurkar, Suday G.; Deshpande, Mohan D.; Kazi, Noaman; Jadhav, Dhanashree; Ranadive, Pallavi; Ingole, Snehal

    2017-01-01

    Aneurysmal Bone cyst (ABC)is a rare benign lesion of the bone which is infrequent in craniofacial region (12%). Rapid growth pattern causing bone expansion and facial asymmetry is a characteristic feature of ABC. Giant cell lesion is another distinct pathological entity. Here we present to you a rare case of dual pathology in an 11 year old female patient who presented with a large expansile lesion in the left hemimandible. All radiographic investigations were suggestive of ABC, aspiration of the lesion resulted in blood aspirate. However only after a histologic examination the dual nature of the lesion was revealed. PMID:29264307

  3. Dual Pathology of Mandible.

    PubMed

    Rajurkar, Suday G; Deshpande, Mohan D; Kazi, Noaman; Jadhav, Dhanashree; Ranadive, Pallavi; Ingole, Snehal

    2017-01-01

    Aneurysmal Bone cyst (ABC)is a rare benign lesion of the bone which is infrequent in craniofacial region (12%). Rapid growth pattern causing bone expansion and facial asymmetry is a characteristic feature of ABC. Giant cell lesion is another distinct pathological entity. Here we present to you a rare case of dual pathology in an 11 year old female patient who presented with a large expansile lesion in the left hemimandible. All radiographic investigations were suggestive of ABC, aspiration of the lesion resulted in blood aspirate. However only after a histologic examination the dual nature of the lesion was revealed.

  4. Fluorescence and Magnetic Resonance Dual-Modality Imaging-Guided Photothermal and Photodynamic Dual-Therapy with Magnetic Porphyrin-Metal Organic Framework Nanocomposites

    NASA Astrophysics Data System (ADS)

    Zhang, Hui; Li, Yu-Hao; Chen, Yang; Wang, Man-Man; Wang, Xue-Sheng; Yin, Xue-Bo

    2017-03-01

    Phototherapy shows some unique advantages in clinical application, such as remote controllability, improved selectivity, and low bio-toxicity, than chemotherapy. In order to improve the safety and therapeutic efficacy, imaging-guided therapy seems particularly important because it integrates visible information to speculate the distribution and metabolism of the probe. Here we prepare biocompatible core-shell nanocomposites for dual-modality imaging-guided photothermal and photodynamic dual-therapy by the in situ growth of porphyrin-metal organic framework (PMOF) on Fe3O4@C core. Fe3O4@C core was used as T2-weighted magnetic resonance (MR) imaging and photothermal therapy (PTT) agent. The optical properties of porphyrin were well remained in PMOF, and PMOF was therefore selected for photodynamic therapy (PDT) and fluorescence imaging. Fluorescence and MR dual-modality imaging-guided PTT and PDT dual-therapy was confirmed with tumour-bearing mice as model. The high tumour accumulation of Fe3O4@C@PMOF and controllable light excitation at the tumour site achieved efficient cancer therapy, but low toxicity was observed to the normal tissues. The results demonstrated that Fe3O4@C@PMOF was a promising dual-imaging guided PTT and PDT dual-therapy platform for tumour diagnosis and treatment with low cytotoxicity and negligible in vivo toxicity.

  5. Major Depressive Disorder and Impulsive Reactivity to Emotion: Toward a Dual Process View of Depression

    PubMed Central

    Carver, Charles S.; Johnson, Sheri L.; Joormann, Jutta

    2012-01-01

    Objective Dual process theories of behavior have been used to suggest that vulnerability to depression involves elevated reactivity to emotions. This study tests that idea, examining self-reported reactivity. Design Comparison between persons with at least one lifetime episode of major depressive disorder (lifetime MDD) and those without this diagnosis, controlling for symptoms of alcohol use (a potential externalizing confound) and current symptoms of depression (a potential state-dependent confound). Methods Undergraduates (N = 120) completed a clinical interview to diagnose lifetime MDD and a series of self-reports bearing on diverse aspects of self-control, including reactivity to emotion. Thirty-four were diagnosed with lifetime MDD; 86 did not meet criteria for MDD. The groups were then compared on three factors underlying the scales assessing self-control. Results The MDD group had higher scores than controls on the two factors that reflect impulsive reactivity to diverse emotions, including emotions that are positive in valence. These effects were not explained by associations with either externalizing symptoms or current depressive symptoms. Conclusions Reflexive reactivity to emotions characterizes depression, in addition to some externalizing problems, and it may deserve study as a potential transdiagnostic feature. PMID:23865405

  6. Learning from the Past: Dual Credit

    ERIC Educational Resources Information Center

    Mansell, Nicole; Justice, Madeline

    2014-01-01

    This study involved identifying, categorizing, and comparing critical incidents related to qualifying dual credit high school students' decisions to enroll or not to enroll in dual credit coursework in either a traditional or early college high school. The purpose of the study was (a) to identify the reasons qualifying students decide to enroll in…

  7. Optimizing dual-energy x-ray parameters for the ExacTrac clinical stereoscopic imaging system to enhance soft-tissue imaging.

    PubMed

    Bowman, Wesley A; Robar, James L; Sattarivand, Mike

    2017-03-01

    , and noise content when compared to dual-energy imaging with no filtration. The surface dose was 0.52 mGy per each stereoscopic view for both clinical single energy technique and the dual-energy technique in both cases of with and without the tin filter. Dual-energy soft-tissue imaging is feasible without additional imaging dose using the ExacTrac stereoscopic imaging system with optimized acquisition parameters and no beam filtration. Addition of a single tin filter for both the high and low energies has noticeable improvements on dual-energy imaging with optimized parameters. Clinical implementation of a dual-energy technique on ExacTrac stereoscopic imaging could improve lung tumor visibility. © 2017 American Association of Physicists in Medicine.

  8. Systematic Review to Inform Dual Tobacco Use Prevention.

    PubMed

    Evans, William Douglas; Horn, Kimberly A; Gray, Tiffany

    2015-10-01

    With more tobacco products now available and heavily marketed, dual tobacco use is increasing among youth. We systematically reviewed literature on dual tobacco use interventions, with an emphasis on mass health communication strategies. The review identified 46 articles meeting initial criteria and ultimately included 8 articles. Included studies reported a mix of health communication and social marketing techniques. Although there is a body of research on dual tobacco use, there is limited literature describing interventions aimed at controlling it. Design and evaluation of such interventions showing reductions in dual use of cigarettes, smokeless, and alternative products would advance the field. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Metal oxide/hydroxide-coated dual-media filter for simultaneous removal of bacteria and heavy metals from natural waters.

    PubMed

    Ahammed, M Mansoor; Meera, V

    2010-09-15

    The present study was conducted to compare the performance of a dual-media filter consisting of manganese oxide-coated (MOCS) and iron hydroxide-coated sand (IOCS) with that of IOCS filter and uncoated sand filter in treating water contaminated by microorganisms, heavy metals and turbidity with a view to its use in simple household water purification devices in developing countries. Long-duration column tests were conducted using two natural waters namely, roof-harvested rainwater and canal water. Performance of the filters showed that dual-media filter was more efficient in removing bacteria and heavy metals compared to IOCS filter, while uncoated sand filter showed very poor performance. The average effluent levels for dual-media filter when tested with rainwater were: turbidity 1.0+/-0.1 NTU; total coliforms 3+/-2 MPN/100 mL; heterotrophic plate count 170+/-20 CFU/mL; zinc 0.06+/-0.01 mg/L, while that for IOCS filter were: turbidity 1.0+/-0.1 NTU; total coliforms 4+/-2 MPN/100 mL; heterotrophic plate count 181+/-37 CFU/mL; zinc 0.20+/-0.07 mg/L. Similar results were obtained for canal water also. Up to 900 bed volumes (BV) could be treated without affecting the efficiency in the case of rainwater, while the filter operation had to be terminated after 500 BV due to excessive headloss in the case of canal water. The study thus showed the potential of the dual-media for use in low-cost household water filters for purification of natural waters. Copyright 2010 Elsevier B.V. All rights reserved.

  10. The gravity duals of modular Hamiltonians

    DOE PAGES

    Jafferis, Daniel L.; Suh, S. Josephine

    2016-09-12

    In this study, we investigate modular Hamiltonians defined with respect to arbitrary spatial regions in quantum field theory states which have semi-classical gravity duals. We find prescriptions in the gravity dual for calculating the action of the modular Hamiltonian on its defining state, including its dual metric, and also on small excitations around the state. Curiously, use of the covariant holographic entanglement entropy formula leads us to the conclusion that the modular Hamiltonian, which in the quantum field theory acts only in the causal completion of the region, does not commute with bulk operators whose entire gauge-invariant description is space-likemore » to the causal completion of the region.« less

  11. The gravity duals of modular Hamiltonians

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Jafferis, Daniel L.; Suh, S. Josephine

    In this study, we investigate modular Hamiltonians defined with respect to arbitrary spatial regions in quantum field theory states which have semi-classical gravity duals. We find prescriptions in the gravity dual for calculating the action of the modular Hamiltonian on its defining state, including its dual metric, and also on small excitations around the state. Curiously, use of the covariant holographic entanglement entropy formula leads us to the conclusion that the modular Hamiltonian, which in the quantum field theory acts only in the causal completion of the region, does not commute with bulk operators whose entire gauge-invariant description is space-likemore » to the causal completion of the region.« less

  12. An Investigation of CTOL Dual-Mode PAVE Concepts

    NASA Technical Reports Server (NTRS)

    Marchman, James F., III; Interatep, Nanyaporn; Skelton, Eugene; Mason, William H.

    2002-01-01

    A study was conducted to assess the feasibility of the dual-mode concept for a personal air vehicle, to determine how constraints differ between the dual-mode concept and a Conventional Takeoff and Landing (CTOL) general aviation aircraft, to recommend a dual-mode vehicle concept, and to recommend areas where further research can contribute to the successful development of a viable PAVE vehicle design.

  13. Dual-filter estimation for rotating-panel sample designs

    Treesearch

    Francis Roesch

    2017-01-01

    Dual-filter estimators are described and tested for use in the annual estimation for national forest inventories. The dual-filter approach involves the use of a moving widow estimator in the first pass, which is used as input to Theil’s mixed estimator in the second pass. The moving window and dual-filter estimators are tested along with two other estimators in a...

  14. Gas Flows in Dual Active Galactic Nuclei

    NASA Astrophysics Data System (ADS)

    Mueller Sanchez, Francisco; Comerford, Julia M.; Davies, Richard; Treister, Ezequiel; Privon, George C.; Nevin, Becky

    2018-06-01

    Dual Active Galactic Nuclei (AGN) are the Rosetta stone to understand the role of galaxy mergers in triggering nuclear activity and regulating black hole (BH) and galaxy growth. But very little is known about the physical processes required to effectively trigger AGN activity and regulate the growth of the two BHs. The work I will present here characterizes for the first time the properties of the stars, gas (molecular, ionized, and highly-ionized) and dust in all the confirmed dual AGN at z < 0.05, using Keck/OSIRIS, VLT/SINFONI, SOFIA/FORCAST, and HST data. I will focus on the interplay between the several complex processes observed in dual AGN, using as an example the prototypical merger system NGC 6240: vigorous star formation, two AGNs, outflowing winds of ionized gas, rippling dust and gas lanes, and tidal tails. In this galaxy, we observe for the first time a dual outflow of different species of gas: an AGN-driven outflow of highly-ionized gas to the northeast and a starburst-driven outflow of ionized hydrogen to the northwest. This shows that stellar feedback and supermassive black hole feedback can work in tandem to regulate the stellar growth of a galaxy after a merger event. These results open a new door to studies of dual AGN and AGN pairs in general, and enable dual AGN to be used, for the first time, for studies of galaxy evolution.

  15. Dual-window dual-bandwidth spectroscopic optical coherence tomography metric for qualitative scatterer size differentiation in tissues.

    PubMed

    Tay, Benjamin Chia-Meng; Chow, Tzu-Hao; Ng, Beng-Koon; Loh, Thomas Kwok-Seng

    2012-09-01

    This study investigates the autocorrelation bandwidths of dual-window (DW) optical coherence tomography (OCT) k-space scattering profile of different-sized microspheres and their correlation to scatterer size. A dual-bandwidth spectroscopic metric defined as the ratio of the 10% to 90% autocorrelation bandwidths is found to change monotonically with microsphere size and gives the best contrast enhancement for scatterer size differentiation in the resulting spectroscopic image. A simulation model supports the experimental results and revealed a tradeoff between the smallest detectable scatterer size and the maximum scatterer size in the linear range of the dual-window dual-bandwidth (DWDB) metric, which depends on the choice of the light source optical bandwidth. Spectroscopic OCT (SOCT) images of microspheres and tonsil tissue samples based on the proposed DWDB metric showed clear differentiation between different-sized scatterers as compared to those derived from conventional short-time Fourier transform metrics. The DWDB metric significantly improves the contrast in SOCT imaging and can aid the visualization and identification of dissimilar scatterer size in a sample. Potential applications include the early detection of cell nuclear changes in tissue carcinogenesis, the monitoring of healing tendons, and cell proliferation in tissue scaffolds.

  16. Desert Dust Satellite Retrieval Intercomparison

    NASA Technical Reports Server (NTRS)

    Carboni, E.; Thomas, G. E.; Sayer, A. M.; Siddans, R.; Poulsen, C. A.; Grainger, R. G.; Ahn, C.; Antoine, D.; Bevan, S.; Braak, R.; hide

    2012-01-01

    This work provides a comparison of satellite retrievals of Saharan desert dust aerosol optical depth (AOD) during a strong dust event through March 2006. In this event, a large dust plume was transported over desert, vegetated, and ocean surfaces. The aim is to identify and understand the differences between current algorithms, and hence improve future retrieval algorithms. The satellite instruments considered are AATSR, AIRS, MERIS, MISR, MODIS, OMI, POLDER, and SEVIRI. An interesting aspect is that the different algorithms make use of different instrument characteristics to obtain retrievals over bright surfaces. These include multi-angle approaches (MISR, AATSR), polarisation measurements (POLDER), single-view approaches using solar wavelengths (OMI, MODIS), and the thermal infrared spectral region (SEVIRI, AIRS). Differences between instruments, together with the comparison of different retrieval algorithms applied to measurements from the same instrument, provide a unique insight into the performance and characteristics of the various techniques employed. As well as the intercomparison between different satellite products, the AODs have also been compared to co-located AERONET data. Despite the fact that the agreement between satellite and AERONET AODs is reasonably good for all of the datasets, there are significant differences between them when compared to each other, especially over land. These differences are partially due to differences in the algorithms, such as as20 sumptions about aerosol model and surface properties. However, in this comparison of spatially and temporally averaged data, at least as significant as these differences are sampling issues related to the actual footprint of each instrument on the heterogeneous aerosol field, cloud identification and the quality control flags of each dataset.

  17. Towards timelike singularity via AdS dual

    NASA Astrophysics Data System (ADS)

    Bhowmick, Samrat; Chatterjee, Soumyabrata

    2017-07-01

    It is well known that Kasner geometry with spacelike singularity can be extended to bulk AdS-like geometry, furthermore, one can study field theory on this Kasner space via its gravity dual. In this paper, we show that there exists a Kasner-like geometry with timelike singularity for which one can construct a dual gravity description. We then study various extremal surfaces including spacelike geodesics in the dual gravity description. Finally, we compute correlators of highly massive operators in the boundary field theory with a geodesic approximation.

  18. Safety and Crashworthiness of Dual Mode Vehicles

    DOT National Transportation Integrated Search

    1974-01-01

    Safety features and the degree of safety expected of dual-mode systems are reviewed. Some of the inherent advantages and disadvantages of dual-mode transportation are also outlined. Possible categories of vehicle safety are defined to aid in developi...

  19. Conflict monitoring in dual process theories of thinking.

    PubMed

    De Neys, Wim; Glumicic, Tamara

    2008-03-01

    Popular dual process theories have characterized human thinking as an interplay between an intuitive-heuristic and demanding-analytic reasoning process. Although monitoring the output of the two systems for conflict is crucial to avoid decision making errors there are some widely different views on the efficiency of the process. Kahneman [Kahneman, D. (2002). Maps of bounded rationality: A perspective on intuitive judgement and choice. Nobel Prize Lecture. Retrieved January 11, 2006, from: http://nobelprize.org/nobel_prizes/economics/laureates/2002/kahnemann-lecture.pdf] and Evans [Evans, J. St. B. T. (1984). Heuristic and analytic processing in reasoning. British Journal of Psychology, 75, 451-468], for example, claim that the monitoring of the heuristic system is typically quite lax whereas others such as Sloman [Sloman, S. A. (1996). The empirical case for two systems of reasoning. Psychological Bulletin, 119, 3-22] and Epstein [Epstein, S. (1994). Integration of the cognitive and psychodynamic unconscious. American Psychologists, 49, 709-724] claim it is flawless and people typically experience a struggle between what they "know" and "feel" in case of a conflict. The present study contrasted these views. Participants solved classic base rate neglect problems while thinking aloud. In these problems a stereotypical description cues a response that conflicts with the response based on the analytic base rate information. Verbal protocols showed no direct evidence for an explicitly experienced conflict. As Kahneman and Evans predicted, participants hardly ever mentioned the base rates and seemed to base their judgment exclusively on heuristic reasoning. However, more implicit measures of conflict detection such as participants' retrieval of the base rate information in an unannounced recall test, decision making latencies, and the tendency to review the base rates indicated that the base rates had been thoroughly processed. On control problems where base rates and

  20. Simultaneous measurement of temperature and emissivity of lunar regolith simulant using dual-channel millimeter-wave radiometry.

    PubMed

    McCloy, J S; Sundaram, S K; Matyas, J; Woskov, P P

    2011-05-01

    Millimeter wave (MMW) radiometry can be used for simultaneous measurement of emissivity and temperature of materials under extreme environments (high temperature, pressure, and corrosive environments). The state-of-the-art dual channel MMW passive radiometer with active interferometric capabilities at 137 GHz described here allows for radiometric measurements of sample temperature and emissivity up to at least 1600 °C with simultaneous measurement of sample surface dynamics. These capabilities have been used to demonstrate dynamic measurement of melting of powders of simulated lunar regolith and static measurement of emissivity of solid samples. The paper presents the theoretical background and basis for the dual-receiver system, describes the hardware in detail, and demonstrates the data analysis. Post-experiment analysis of emissivity versus temperature allows further extraction from the radiometric data of millimeter wave viewing beam coupling factors, which provide corroboratory evidence to the interferometric data of the process dynamics observed. These results show the promise of the MMW system for extracting quantitative and qualitative process parameters for industrial processes and access to real-time dynamics of materials behavior in extreme environments.

  1. [Application of second generation dual-source computed tomography dual-energy scan mode in detecting pancreatic adenocarcinoma].

    PubMed

    Xue, Hua-dan; Liu, Wei; Sun, Hao; Wang, Xuan; Chen, Yu; Su, Bai-yan; Sun, Zhao-yong; Chen, Fang; Jin, Zheng-yu

    2010-12-01

    To analyze the clinical value of multiple sequences derived from dual-source computed tomography (DSCT) dual-energy scan mode in detecting pancreatic adenocarcinoma. Totally 23 patients with clinically or pathologically diagnosed pancreatic cancer were enrolled in this retrospective study. DSCT (Definition Flash) was used and dual-energy scan mode was used in their pancreatic parenchyma phase scan (100kVp/230mAs and Sn140kVp/178mAs) . Mono-energetic 60kev, mono-energetic 80kev, mono-energetic 100kev, mono-energetic 120kev, linear blend image, non-linear blend image, and iodine map were acquired. pancreatic parenchyma-tumor CT value difference, ratio of tumor to pancreatic parenchyma, and pancreatic parenchyma-tumor contrast to noise ratio were calculated. One-way ANOVA was used for the comparison of diagnostic values of the above eight different dual-energy derived sequences for pancreatic cancer. The pancreatic parenchyma-tumor CT value difference, ratio of tumor to pancreatic parenchyma, and pancreatic parenchyma-tumor contrast to noise ratio were significantly different among eight sequences (P<0.05) . Mono-energetic 60kev image showed the largest parenchyma-tumor CT value [ (77.53 ± 23.42) HU] , and iodine map showed the lowest tumor/parenchyma enhancement ratio (0.39?0.12) and the largest contrast to noise ratio (4.08 ± 1.46) . Multiple sequences can be derived from dual-energy scan mode with DSCT via multiple post-processing methods. Integration of these sequences may further improve the sensitivity of the multislice spiral CT in the diagnosis of pancreatic cancer.

  2. Continuous 1052, 1064 nm dual-wavelength Nd:YAG laser

    NASA Astrophysics Data System (ADS)

    Wang, Xiaozhong; Yuan, Haiyang; Wang, Mingshan; Huang, Wencai

    2016-10-01

    Dual-wavelength lasers are usually obtained through balancing the net gain of the two oscillating lines. Competition between transitions 1052 nm, 1061 nm and 1064 nm is utilized to realize a continuous wave 1052 and 1064 nm dual-wavelength Nd:YAG laser firstly in this paper. A specially designed Fabry-Perot band-pass filter is exploited as output coupler to control the thresholds of the oscillating wavelengths. The maximum power of the dual-wavelength laser is 1.6 W and the slope efficiency is about 10%. The power instability of the output dual-wavelength laser is smaller than ±4% in half an hour. The mechanism presented in this paper may provide a new way to obtain dual-wavelength lasers.

  3. Dual-throat thruster thermal model

    NASA Technical Reports Server (NTRS)

    Ewen, R. L.; Obrien, C. J.; Matthews, L. W.

    1986-01-01

    The dual-throat engine is one of the dual nozzle engine concepts studied for advanced space transportation applications. It provides a thrust change and an in-flight area ratio change through the use of two concentric combustors with their throats arranged in series. Test results are presented for a dual throat thruster burning gaseous oxygen and hydrogen at primary (inner) chamber pressures from 380 to 680 psia. Heat flux profiles were obtained from calorimetric cooling channels in the inner nozzle, outer or secondary chamber and the tip of the inner nozzle. Data were obtained for two nozzle spacings over a chamber pressure ratio (secondary/primary) range of 0.45 to 0.83 with both chambers firing (Mode I). Fluxes near the end of the inner nozzle were significantly higher than in Mode II when only the inner chamber was fired, due to the flow separation and recirculation caused by the back pressure imposed by the secondary chamber. As the pressure ratio increased, these heat fluxes increased and the region of high heat flux relative to Mode II extended farther upstream. The use of the gaseous hydrogen bleed flow in the secondary chamber to control heat fluxes in the primary plume attachment region was investigated in Mode II testing. A thermal model of a dual throat thruster was developed and upgraded using the experimental data.

  4. New Processes for Freeze-Drying in Dual-Chamber Systems.

    PubMed

    Werk, T; Ludwig, I S; Luemkemann, J; Huwyler, J; Mahler, H-C; Haeuser, C R; Hafner, M

    2016-01-01

    Dual-chamber systems can offer self-administration and home care use for lyophilized biologics. Only a few products have been launched in dual-chamber systems so far-presumably due to dual-chamber systems' complex and costly drug product manufacturing process. Within this paper, two improved processes (both based on tray filling technology) for freeze-drying pharmaceuticals in dual-chamber systems are described. Challenges with regards to heat transfer were tackled by (1) performing the freeze-drying step in a needle-down orientation in combination with an aluminum block, or (2) freeze-drying the drug product "externally" in a metal cartridge with subsequent filling of the lyophilized cake into the dual-chamber system. Metal-mediated heat transfer was shown to be efficient in both cases and batch (unit-to-unit) homogeneity with regards to sublimation rate was increased. It was difficult to influence ice crystal size using different methods when in use with an aluminum block due to its heat capacity. Using such a metal carrier implies a large heat capacity leading to relatively small ice crystals. Compared to the established process, drying times were reduced by half using the new processes. The drying time was, however, longer for syringes compared to vials due to the syringe design (long and slim). The differences in drying times were less pronounced for aggressive drying cycles. The proposed processes may help to considerably decrease investment costs into dual-chamber system fill-finish equipment. Dual-chamber syringes offer self-administration and home care use for freeze-dried pharmaceuticals. Only a few products have been launched in dual-chamber syringes so far-presumably due to their complex and costly drug product manufacturing process. In this paper two improved processes for freeze-drying pharmaceuticals in dual-chamber syringes are described. The major challenge of freeze-drying is to transfer heat through a vacuum. The proposed processes cope with this

  5. Aging and the Vulnerability of Speech to Dual Task Demands

    PubMed Central

    Kemper, Susan; Schmalzried, RaLynn; Hoffman, Lesa; Herman, Ruth

    2010-01-01

    Tracking a digital pursuit rotor task was used to measure dual task costs of language production by young and older adults. Tracking performance by both groups was affected by dual task demands: time on target declined and tracking error increased as dual task demands increased from the baseline condition to a moderately demanding dual task condition to a more demanding dual task condition. When dual task demands were moderate, older adults’ speech rate declined but their fluency, grammatical complexity, and content were unaffected. When the dual task was more demanding, older adults’ speech, like young adults’ speech, became highly fragmented, ungrammatical, and incoherent. Vocabulary, working memory, processing speed, and inhibition affected vulnerability to dual task costs: vocabulary provided some protection for sentence length and grammaticality, working memory conferred some protection for grammatical complexity, and processing speed provided some protection for speech rate, propositional density, coherence, and lexical diversity. Further, vocabulary and working memory capacity provided more protection for older adults than for young adults although the protective effect of processing speed was somewhat reduced for older adults as compared to the young adults. PMID:21186917

  6. Dual practice in the health sector: review of the evidence

    PubMed Central

    Ferrinho, Paulo; Van Lerberghe, Wim; Fronteira, Inês; Hipólito, Fátima; Biscaia, André

    2004-01-01

    This paper reports on income generation practices among civil servants in the health sector, with a particular emphasis on dual practice. It first approaches the subject of public–private overlap. Thereafter it focuses on coping strategies in general and then on dual practice in particular. To compensate for unrealistically low salaries, health workers rely on individual coping strategies. Many clinicians combine salaried, public-sector clinical work with a fee-for-service private clientele. This dual practice is often a means by which health workers try to meet their survival needs, reflecting the inability of health ministries to ensure adequate salaries and working conditions. Dual practice may be considered present in most countries, if not all. Nevertheless, there is surprisingly little hard evidence about the extent to which health workers resort to dual practice, about the balance of economic and other motives for doing so, or about the consequences for the proper use of the scarce public resources dedicated to health. In this paper dual practice is approached from six different perspectives: (1) conceptual, regarding what is meant by dual practice; (2) descriptive, trying to develop a typology of dual practices; (3) quantitative, trying to determine its prevalence; (4) impact on personal income, the health care system and health status; (5) qualitative, looking at the reasons why practitioners so frequently remain in public practice while also working in the private sector and at contextual, personal life, institutional and professional factors that make it easier or more difficult to have dual practices; and (6) possible interventions to deal with dual practice. PMID:15509305

  7. Dual Heat Pulse, Dual Layer Thermal Protection System Sizing Analysis and Trade Studies for Human Mars Entry Descent and Landing

    NASA Technical Reports Server (NTRS)

    McGuire, Mary Kathleen

    2011-01-01

    NASA has been recently updating design reference missions for the human exploration of Mars and evaluating the technology investments required to do so. The first of these started in January 2007 and developed the Mars Design Reference Architecture 5.0 (DRA5). As part of DRA5, Thermal Protection System (TPS) sizing analysis was performed on a mid L/D rigid aeroshell undergoing a dual heat pulse (aerocapture and atmospheric entry) trajectory. The DRA5 TPS subteam determined that using traditional monolithic ablator systems would be mass expensive. They proposed a new dual-layer TPS concept utilizing an ablator atop a low thermal conductivity insulative substrate to address the issue. Using existing thermal response models for an ablator and insulative tile, preliminary hand analysis of the dual layer concept at a few key heating points indicated that the concept showed potential to reduce TPS masses and warranted further study. In FY09, the followon Entry, Descent and Landing Systems Analysis (EDL-SA) project continued by focusing on Exploration-class cargo or crewed missions requiring 10 to 50 metric tons of landed payload. The TPS subteam advanced the preliminary dual-layer TPS analysis by developing a new process and updated TPS sizing code to rapidly evaluate mass-optimized, full body sizing for a dual layer TPS that is capable of dual heat pulse performance. This paper describes the process and presents the results of the EDL-SA FY09 dual-layer TPS analyses on the rigid mid L/D aeroshell. Additionally, several trade studies were conducted with the sizing code to evaluate the impact of various design factors, assumptions and margins.

  8. Currarino triad with dual pathology in the presacral mass: report of a case.

    PubMed

    Thambidorai, C R; Muin, I; Razman, J; Zulfiqar, A

    2003-07-01

    Currarino triad, which comprises anorectal stenosis, anterior sacral defect, and a presacral mass, is an uncommon cause of constipation in children and adults. The presacral mass in this triad is most often caused by an anterior sacral meningocele, a teratoma, or an enterogenous cyst, but rarely may be caused by dual pathology. A neonate with Currarino triad and dual pathology in the presacral mass is described in this report. A male Chinese neonate, who presented with abdominal distention and constipation on the second day of life, was found to have features of Currarino triad. Colostomy was done in the neonatal period, and the presacral mass was excised by posterior sagittal perineal approach at the age of six months. The excised presacral mass consisted of an anterior meningocele and a teratoma. The patient continued to have constipation during follow-up and required anorectoplasty to correct residual anorectal stenosis. At the time of this report the patient was three years old and growing normally with normal anorectal function. Of a total of about 200 cases of complete Currarino triad found in the literature, in only 22 patients did the presacral mass contain both meningocele and teratoma. The features of these 22 patients and the current views on the surgical management of Currarino triad are discussed.

  9. Human Factors Engineering: Current and Emerging Dual-Use Applications

    NASA Technical Reports Server (NTRS)

    Chandlee, G. O.; Goldsberry, B. S.

    1994-01-01

    Human Factors Engineering is a multidisciplinary endeavor in which information pertaining to human characteristics is used in the development of systems and machines. Six representatives considered to be experts from the public and private sectors were surveyed in an effort to identify the potential dual-use of human factors technology. Each individual was asked to provide a rating as to the dual-use of 85 identified NASA technologies. Results of the survey were as follows: nearly 75 percent of the technologies were identified at least once as high dual-use by one of the six survey respondents, and nearly 25 percent of the identified NASA technologies were identified as high dual-use technologies by a majority of the respondents. The perceived level of dual-use appeared to be independent of the technology category. Successful identification of dual-use technology requires expanded input from industry. As an adjunct, cost-benefit analysis should be conducted to identify the feasibility of the dual-use technology. Concurrent with this effort should be an examination of precedents established by other technologies in other industrial settings. Advances in human factors and systems engineering are critical to reduce risk in any workplace and to enhance industrial competitiveness.

  10. Analysis of preservatives with different polarities in beverage samples by dual-phase dual stir bar sorptive extraction combined with high-performance liquid chromatography.

    PubMed

    Xu, Jin; Chen, Beibei; He, Man; Hu, Bin

    2013-02-22

    A new concept of "dual-phase dual stir bar sorptive extraction (SBSE)" was proposed to simultaneously extract six preservatives with different polarities (logKo/w values of 1.27-3.41), namely, benzoic acid (BA), sorbic acid (SA), methyl p-hydroxybenzoate (MP), ethyl p-hydroxybenzoate (EP), propyl p-hydroxybenzoate (PP), and butyl p-hydroxybenzoate (BP). The dual-phase dual SBSE apparatus was consisted of two differently coated stir bars, a 3-aminopropyltriethoxysilane (APTES)-hydroxy-terminated silicone oil (OH-TSO)-coated stir bar that was prepared by sol-gel technique and a C(18) silica (C(18))-polydimethylsiloxane (PDMS)-coated stir bar that was prepared by adhesion. In dual-phase dual SBSE, the two stir bars with different coatings were placed in the same sample solution for the simultaneous extraction of the target analytes with different polarities, and then the bars were desorbed in the same desorption solvent. The extraction performance of the dual-phase dual SBSE for the six preservatives was evaluated by comparing with the conventional SBSE (individual stir bar) with different coatings, including commercial PDMS, homemade PDMS, C(18)-APTES-OH-TSO, APTES-OH-TSO, and C(18)-PDMS. The experimental results showed that the dual-phase dual SBSE had the highest extraction efficiency for the six target preservatives. Based on this fact, a novel method by combining the dual-phase dual SBSE which was consisted of the APTES-OH-TSO-coated and C(18)-PDMS-coated stir bars with high-performance liquid chromatography-ultraviolet detection (HPLC-UV) was developed for the simultaneous analysis of six target beverage preservatives in beverages. Under optimal conditions, the limits of detection (LODs) for six target preservatives ranged from 0.6 to 2.7 μgL(-1) with the relative standard deviations (RSDs) of 4.6-9.2% (C(BA,SA)=5 μgL(-1),C(MP)=20 μgL(-1),C(EP,PP,BP)=10 μgL(-1), n=7). The enrichment factors (EFs) were approximately 16-42-fold (theoretical EF was 50-fold

  11. Assimilation of Dual-Polarimetric Radar Observations with WRF GSI

    NASA Technical Reports Server (NTRS)

    Li, Xuanli; Mecikalski, John; Fehnel, Traci; Zavodsky, Bradley; Srikishen, Jayanthi

    2014-01-01

    Dual-polarimetric (dual-pol) radar typically transmits both horizontally and vertically polarized radio wave pulses. From the two different reflected power returns, more accurate estimate of liquid and solid cloud and precipitation can be provided. The upgrade of the traditional NWS WSR-88D radar to include dual-pol capabilities will soon be completed for the entire NEXRAD network. Therefore, the use of dual-pol radar network will have a broad impact in both research and operational communities. The assimilation of dual-pol radar data is especially challenging as few guidelines have been provided by previous research. It is our goal to examine how to best use dual-pol radar data to improve forecast of severe storm and forecast initialization. In recent years, the Development Testbed Center (DTC) has released the community Gridpoint Statistical Interpolation (GSI) DA system for the Weather Research and Forecasting (WRF) model. The community GSI system runs in independently environment, yet works functionally equivalent to operational centers. With collaboration with the NASA Short-term Prediction Research and Transition (SPoRT) Center, this study explores regional assimilation of the dual-pol radar variables from the WSR-88D radars for real case storms. Our presentation will highlight our recent effort on incorporating the horizontal reflectivity (ZH), differential reflectivity (ZDR), specific differential phase (KDP), and radial velocity (VR) data for initializing convective storms, with a significant focus being on an improved representation of hydrometeor fields. In addition, discussion will be provided on the development of enhanced assimilation procedures in the GSI system with respect to dual-pol variables. Beyond the dual-pol variable assimilation procedure developing within a GSI framework, highresolution (=1 km) WRF model simulations and storm scale data assimilation experiments will be examined, emphasizing both model initialization and short-term forecast

  12. Imaging system for cardiac planar imaging using a dedicated dual-head gamma camera

    DOEpatents

    Majewski, Stanislaw [Morgantown, VA; Umeno, Marc M [Woodinville, WA

    2011-09-13

    A cardiac imaging system employing dual gamma imaging heads co-registered with one another to provide two dynamic simultaneous views of the heart sector of a patient torso. A first gamma imaging head is positioned in a first orientation with respect to the heart sector and a second gamma imaging head is positioned in a second orientation with respect to the heart sector. An adjustment arrangement is capable of adjusting the distance between the separate imaging heads and the angle between the heads. With the angle between the imaging heads set to 180 degrees and operating in a range of 140-159 keV and at a rate of up to 500kHz, the imaging heads are co-registered to produce simultaneous dynamic recording of two stereotactic views of the heart. The use of co-registered imaging heads maximizes the uniformity of detection sensitivity of blood flow in and around the heart over the whole heart volume and minimizes radiation absorption effects. A normalization/image fusion technique is implemented pixel-by-corresponding pixel to increase signal for any cardiac region viewed in two images obtained from the two opposed detector heads for the same time bin. The imaging system is capable of producing enhanced first pass studies, bloodpool studies including planar, gated and non-gated EKG studies, planar EKG perfusion studies, and planar hot spot imaging.

  13. [LONG-TERM SURVIVAL OF DUAL DISORDERS PATIENTS AFTER MIXED CARE IN DUAL DISORDERS AND STANDARD WARDS VERSUS CARE ONLY IN DUAL DISORDERS WARD].

    PubMed

    Gimelfarb, Yuri; Wolf, Aviva; Ben-Tzarfati, Mashit

    2017-01-01

    Dual disorders (co-occurring mental illness and substance abuse disorders in the same person) are extremely common among patients receiving mental health services. Integrated treatment has been proposed as the standard of care and it describes a flexible combination of treatments from the mental health and addiction fields that are blended together in the therapy. Scientific evidence for survival of dual disorders patients (DDPs), who had integrated dual disorders inpatient care, is lacking. To determine the long term survival rates following integrated care (Integrated Dual Diagnosis Treatment Ward [IDDTW] only) versus mixed care (IDDTW and psychiatric wards) during the life-time of DDPs. The charts of 333 subjects admitted to IDDTW during the period January 2002 - June 2006 were assessed at least 8 years after the first admission. Psychiatric diagnoses have been established and grouped according to international classification of diseases and health-related problems -10th edition (ICD-10). The Kaplan-Meier survival analysis was used to estimate the cumulative survival rates in all the subpopulations, and the predictive values of different variables were assessed by Cox proportional-hazards regression model. The total all-cause 12-year, unadjusted mortality was 21.1% in integrated care versus 24.6% in mixed care (p<.68). The Cox regression was not revealed for integrated care as a predictive factor for all-cause mortality. The findings showed that there was no consistent evidence to support integrated inpatient care over mixed care, as measured by long-term survival. More studies are required in order to address the challenges posed in the treatment of DDPs.

  14. Dual job holding by public sector health professionals in highly resource-constrained settings: problem or solution?

    PubMed Central

    Jan, Stephen; Bian, Ying; Jumpa, Manuel; Meng, Qingyue; Nyazema, Norman; Prakongsai, Phusit; Mills, Anne

    2005-01-01

    This paper examines the policy options for the regulation of dual job holding by medical professionals in highly resource-constrained settings. Such activity is generally driven by a lack of resources in the public sector and low pay, and has been associated with the unauthorized use of public resources and corruption. It is also typically poorly regulated; regulations are either lacking, or when they exist, are vague or poorly implemented because of low regulatory capacity. This paper draws on the limited evidence available on this topic to assess a number of regulatory options in relation to the objectives of quality of care and access to services, as well as some of the policy constraints that can undermine implementation in resource-poor settings. The approach taken in highlighting these broader social objectives seeks to avoid the value judgements regarding dual working and some of its associated forms of behaviour that have tended to characterize previous analyses. Dual practice is viewed as a possible system solution to issues such as limited public sector resources (and incomes), low regulatory capacity and the interplay between market forces and human resources. This paper therefore offers some support for policies that allow for the official recognition of such activity and embrace a degree of professional self-regulation. In providing clearer policy guidance, future research in this area needs to adopt a more evaluative approach than that which has been used to date. PMID:16283054

  15. Differences Between Dual-Method and Non–Dual-Method Protection Use in a Sample of Young African American Women Residing in the Southeastern United States

    PubMed Central

    Sales, Jessica M.; Latham, Teaniese P.; DiClemente, Ralph J.; Rose, Eve

    2013-01-01

    Objectives To characterize dual-method protection users and report the prevalence of dual-method use among young adult African American women residing in the Southeastern United States. Design Analysis of baseline data from a randomized controlled trial. Setting A clinic-based sample of young women enrolled in a randomized trial of a human immunodeficiency virus (HIV)–prevention program in Atlanta, Georgia, from June 2005 to June 2007. Participants African American women aged 14 to 20 years who reported unprotected sexual activity in the past 6months. Of the eligible adolescents, 94% (N=701) were enrolled in the study and completed baseline assessments. Outcome Measures Dual-method protection use as well as sociodemographic, individual-level, interpersonal-level, and community-level factors and interpersonal communication skills. Only data from the baseline assessment, before randomization, were used for the analysis. Results A total of 102 participants (14.6%) were classified as dual-method protection users. After controlling for age and clinic, significant differences between dual-method users and non–dual-method users were found for impulsivity, self-esteem, social support, relationship style, partner communication self-efficacy, and fear of condom negotiation. Conclusions Dual-method protection use is low. Identification of factors that differentiate dual-method users from non–dual-method users at the individual, interpersonal, and community levels in this young African American sample suggests that HIV, sexually transmitted disease, and unintended pregnancy risk–reduction programs should address factors at each level, not simply the individual level, and that this may involve structural and/or clinical counseling practice changes in clinics that serve young women, to optimally facilitate dual-method protection use among young African American women in the Southeastern United States. PMID:21135341

  16. Dual Contraceptive Method Use Among Youth in Alternative Schools.

    PubMed

    Coyle, Karin K; Peterson, Amy J; Franks, Heather M; Anderson, Pamela M; Glassman, Jill R

    2016-12-01

    Dual contraceptive method use, or using a highly effective contraceptive method plus a barrier method like condoms, is gaining attention as a strategy for preventing unplanned pregnancy and sexually transmitted diseases. We investigated rates of dual method use among a sample of youth in urban alternative schools, and explored the relationship between dual method use and sexual partner type. The study analyzed data from 765 students enrolled in 11 district-run continuation high schools in northern California. We explored the association between dual method use and sexual partner type (steady only, a mix of steady and non-steady, and non-steady only) using logistic regression. Differences in dual rates by partner type were statistically significant, with higher rates of dual methods use reported among young people reporting non-steady sexual partners only, as compared to those with steady partners only. The data illustrate that young people in alternative school settings could gain from further intervention on the benefits, skills, and challenges of using two methods of contraception as opposed to one with both steady and non-steady sexual partners.

  17. Fostering radical conceptual change through dual-situated learning model

    NASA Astrophysics Data System (ADS)

    She, Hsiao-Ching

    2004-02-01

    This article examines how the Dual-Situated Learning Model (DSLM) facilitates a radical change of concepts that involve the understanding of matter, process, and hierarchical attributes. The DSLM requires knowledge of students' prior beliefs of science concepts and the nature of these concepts. In addition, DSLM also serves two functions: it creates dissonance with students' prior knowledge by challenging their epistemological and ontological beliefs about science concepts, and it provides essential mental sets for students to reconstruct a more scientific view of the concepts. In this study, the concept heat transfer: heat conduction and convection, which requires an understanding of matter, process, and hierarchical attributes, was chosen to examine how DSLM can facilitate radical conceptual change among students. Results show that DSLM has great potential to foster a radical conceptual change process in learning heat transfer. Radical conceptual change can definitely be achieved and does not necessarily involve a slow or gradual process.

  18. 46 CFR 183.324 - Dual voltage generators.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Dual voltage generators. 183.324 Section 183.324 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS (UNDER 100 GROSS TONS) ELECTRICAL INSTALLATION Power Sources and Distribution Systems § 183.324 Dual voltage generators...

  19. 46 CFR 183.324 - Dual voltage generators.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Dual voltage generators. 183.324 Section 183.324 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS (UNDER 100 GROSS TONS) ELECTRICAL INSTALLATION Power Sources and Distribution Systems § 183.324 Dual voltage generators...

  20. 46 CFR 183.324 - Dual voltage generators.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Dual voltage generators. 183.324 Section 183.324 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS (UNDER 100 GROSS TONS) ELECTRICAL INSTALLATION Power Sources and Distribution Systems § 183.324 Dual voltage generators...

  1. 46 CFR 183.324 - Dual voltage generators.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Dual voltage generators. 183.324 Section 183.324 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS (UNDER 100 GROSS TONS) ELECTRICAL INSTALLATION Power Sources and Distribution Systems § 183.324 Dual voltage generators...

  2. Isogeometric Bézier dual mortaring: Refineable higher-order spline dual bases and weakly continuous geometry

    NASA Astrophysics Data System (ADS)

    Zou, Z.; Scott, M. A.; Borden, M. J.; Thomas, D. C.; Dornisch, W.; Brivadis, E.

    2018-05-01

    In this paper we develop the isogeometric B\\'ezier dual mortar method. It is based on B\\'ezier extraction and projection and is applicable to any spline space which can be represented in B\\'ezier form (i.e., NURBS, T-splines, LR-splines, etc.). The approach weakly enforces the continuity of the solution at patch interfaces and the error can be adaptively controlled by leveraging the refineability of the underlying dual spline basis without introducing any additional degrees of freedom. We also develop weakly continuous geometry as a particular application of isogeometric B\\'ezier dual mortaring. Weakly continuous geometry is a geometry description where the weak continuity constraints are built into properly modified B\\'ezier extraction operators. As a result, multi-patch models can be processed in a solver directly without having to employ a mortaring solution strategy. We demonstrate the utility of the approach on several challenging benchmark problems. Keywords: Mortar methods, Isogeometric analysis, B\\'ezier extraction, B\\'ezier projection

  3. Perceptual Space of Superimposed Dual-Frequency Vibrations in the Hands.

    PubMed

    Hwang, Inwook; Seo, Jeongil; Choi, Seungmoon

    2017-01-01

    The use of distinguishable complex vibrations that have multiple spectral components can improve the transfer of information by vibrotactile interfaces. We investigated the qualitative characteristics of dual-frequency vibrations as the simplest complex vibrations compared to single-frequency vibrations. Two psychophysical experiments were conducted to elucidate the perceptual characteristics of these vibrations by measuring the perceptual distances among single-frequency and dual-frequency vibrations. The perceptual distances of dual-frequency vibrations between their two frequency components along their relative intensity ratio were measured in Experiment I. The estimated perceptual spaces for three frequency conditions showed non-linear perceptual differences between the dual-frequency and single-frequency vibrations. A perceptual space was estimated from the measured perceptual distances among ten dual-frequency compositions and five single-frequency vibrations in Experiment II. The effect of the component frequency and the frequency ratio was revealed in the perceptual space. In a percept of dual-frequency vibration, the lower frequency component showed a dominant effect. Additionally, the perceptual difference among single-frequency and dual-frequency vibrations were increased with a low relative difference between two frequencies of a dual-frequency vibration. These results are expected to provide a fundamental understanding about the perception of complex vibrations to enrich the transfer of information using vibrotactile stimuli.

  4. Implications of dual practice for universal health coverage.

    PubMed

    McPake, Barbara; Russo, Giuliano; Hipgrave, David; Hort, Krishna; Campbell, James

    2016-02-01

    Making progress towards universal health coverage (UHC) requires that health workers are adequate in numbers, prepared for their jobs and motivated to perform. In establishing the best ways to develop the health workforce, relatively little attention has been paid to the trends and implications of dual practice - concurrent employment in public and private sectors. We review recent research on dual practice for its potential to guide staffing policies in relation to UHC. Many studies describe the characteristics and correlates of dual practice and speculate about impacts, but there is very little evidence that is directly relevant to policy-makers. No studies have evaluated the impact of policies on the characteristics of dual practice or implications for UHC. We address this lack and call for case studies of policy interventions on dual practice in different contexts. Such research requires investment in better data collection and greater determination on the part of researchers, research funding bodies and national research councils to overcome the difficulties of researching sensitive topics of health systems functions.

  5. Muscle fat fraction in neuromuscular disorders: dual-echo dual-flip-angle spoiled gradient-recalled MR imaging technique for quantification--a feasibility study.

    PubMed

    Gaeta, Michele; Scribano, Emanuele; Mileto, Achille; Mazziotti, Silvio; Rodolico, Carmelo; Toscano, Antonio; Settineri, Nicola; Ascenti, Giorgio; Blandino, Alfredo

    2011-05-01

    To prospectively evaluate the muscle fat fraction (MFF) measured with dual-echo dual-flip-angle spoiled gradient-recalled acquisition in the steady state (SPGR) magnetic resonance (MR) imaging technique by using muscle biopsy as the reference standard. After ethics approval, written informed consent from all patients was obtained. Twenty-seven consecutive patients, evaluated at the Neuromuscular Disorders Center with a possible diagnosis of neuromuscular disorder, were prospectively studied with MR imaging of the lower extremities to quantify muscle fatty infiltration by means of MFF calculation. Spin-density- and T1-weighted fast SPGR in-phase and opposed-phase dual-echo sequences were performed, respectively, with 20° and 80° flip angles. Round regions of interest were drawn by consensus on selected MR sections corresponding to anticipated biopsy sites. These were marked on the patient's skin with a pen by using the infrared spider light of the system, and subsequent muscle biopsy was performed. MR images with regions of interest were stored on a secondary console where the MFF calculation was performed by another radiologist blinded to the biopsy results. MFFs calculated with dual-echo dual-flip-angle SPGR MR imaging and biopsy were compared by using a paired t test, Pearson correlation coefficient, and Bland-Altman plots. P value of < .05 was considered to indicate a statistically significant difference. The mean MFFs obtained with dual-echo dual-flip-angle SPGR MR imaging and biopsy were 20.3% (range, 1.7%-45.1%) and 20.6% (range, 3%-46.1%), respectively. The mean difference, standard deviation of the difference, and t value were -0.3, 1.3, and -1.3 (P > .2), respectively. The Pearson correlation coefficient was 0.995; with the Bland-Altman method, all data points were within the ± 2 SDs limits of agreement. The results show that dual-echo dual-flip-angle SPGR MR imaging technique provides reliable calculation of MFF, consistent with biopsy measurements

  6. Targeted vertical cross-sectional imaging with handheld near-infrared dual axes confocal fluorescence endomicroscope.

    PubMed

    Qiu, Zhen; Liu, Zhongyao; Duan, Xiyu; Khondee, Supang; Joshi, Bishnu; Mandella, Michael J; Oldham, Kenn; Kurabayashi, Katsuo; Wang, Thomas D

    2013-02-01

    We demonstrate vertical cross-sectional (XZ-plane) images of near-infrared (NIR) fluorescence with a handheld dual axes confocal endomicroscope that reveals specific binding of a Cy5.5-labeled peptide to pre-malignant colonic mucosa. This view is perpendicular to the tissue surface, and is similar to that used by pathologists. The scan head is 10 mm in outer diameter (OD), and integrates a one dimensional (1-D) microelectromechanical systems (MEMS) X-axis scanner and a bulky lead zirconate titanate (PZT) based Z-axis actuator. The microscope images in a raster-scanning pattern with a ±6 degrees (mechanical) scan angle at ~3 kHz in the X-axis (fast) and up to 10 Hz (0-400 μm) in the Z-axis (slow). Vertical cross-sectional fluorescence images are collected with a transverse and axial resolution of 4 and 5 μm, respectively, over a field-of-view of 800 μm (width) × 400 μm (depth). NIR vertical cross-sectional fluorescence images of fresh mouse colonic mucosa demonstrate histology-like imaging performance with this miniature instrument.

  7. Targeted vertical cross-sectional imaging with handheld near-infrared dual axes confocal fluorescence endomicroscope

    PubMed Central

    Qiu, Zhen; Liu, Zhongyao; Duan, Xiyu; Khondee, Supang; Joshi, Bishnu; Mandella, Michael J.; Oldham, Kenn; Kurabayashi, Katsuo; Wang, Thomas D.

    2013-01-01

    We demonstrate vertical cross-sectional (XZ-plane) images of near-infrared (NIR) fluorescence with a handheld dual axes confocal endomicroscope that reveals specific binding of a Cy5.5-labeled peptide to pre-malignant colonic mucosa. This view is perpendicular to the tissue surface, and is similar to that used by pathologists. The scan head is 10 mm in outer diameter (OD), and integrates a one dimensional (1-D) microelectromechanical systems (MEMS) X-axis scanner and a bulky lead zirconate titanate (PZT) based Z-axis actuator. The microscope images in a raster-scanning pattern with a ±6 degrees (mechanical) scan angle at ~3 kHz in the X-axis (fast) and up to 10 Hz (0–400 μm) in the Z-axis (slow). Vertical cross-sectional fluorescence images are collected with a transverse and axial resolution of 4 and 5 μm, respectively, over a field-of-view of 800 μm (width) × 400 μm (depth). NIR vertical cross-sectional fluorescence images of fresh mouse colonic mucosa demonstrate histology-like imaging performance with this miniature instrument. PMID:23412564

  8. Excitatory and inhibitory effects of opiates in the rat vas deferens: a dual mechanism of opiate action.

    PubMed

    Jacquet, Y F

    1980-10-03

    Both natural (-)-morphine and its unnatural enantiomer (+)-morphine exert an excitatory action on electrically stimulated contractions of rat vas deferens. Preexposure to (-)-morphine results in cross-tolerance to the inhibitory action of beta-endorphin. (-)-Naloxone and its stereoisomer (+)-naloxone also exert an excitatory action, but only (-)-naloxone bocks the inhibtory action of beta-endorphin. Thus morphine exerts a dual action on a peripheral organ: one an inhibitory action mediated by the stereospecific endorphin receptor that is blocked stereospecifically by naloxone, the other an excitatory action mediated by a nonstereospecific receptor that is not blocked by naloxone. The opiate abstinence syndrome is seen as due to the unmasking of the excitatory action of opiates when its concomitant inhibitory influence is removed by selective blockade by naloxone or weakened by selective tolerance. The view that the rat vas deferens is devoid of morphine receptors is now seen as arising from a reverse example of morphine's dual action: the masking of the inhibitory action of morphine by its concomitant and more potent excitatory action.

  9. Dual-Frequency VLBI Study of Centaurus A on Sub-Parsec Scales: The Highest-Resolution View of an Extragalactic Jet

    NASA Technical Reports Server (NTRS)

    Mueller, C.; Kadler, M.; Ojha, R.; Wilms, J.; Boeck, M.; Edwards, P.; Fromm, C. M.; Hase, H.; Horiuchi, S.; Katz, U.; hide

    2011-01-01

    Centaurus A is the closest active galactic nucleus. High resolution imaging using Very Long Baseline Interferometry (VLBI) enables us to study the spectral and kinematic behavior of the radio jet-<:ounterjet system on sub-parsec scales, providing essential information for jet emission and formation models. Aims. Our aim is to study the structure and spectral shape of the emission from the central-parsec region of Cen A. Methods. As a target of the Southern Hemisphere VLBI monitoring program TANAMI (Tracking Active Galactic Nuclei with Millliarcsecond Interferometry), VLBI observations of Cen A are made regularly at 8.4 and 22.3 GHz with the Australian Long Baseline Array (LBA) and associated telescopes in Antarctica, Chile, and South Africa. Results. The first dual-frequency images of this source are presented along with the resulting spectral index map. An angular resolution of 0.4 mas x 0.7 mas is achieved at 8.4 GHz, corresponding to a linear scale of less than 0.013 pc. Hence, we obtain the highest resolution VLBI image of Cen A, comparable to previous space-VLBI observations. By combining with the 22.3 GHz image, we present the corresponding dual-frequency spectral index distribution along the sub-parsec scale jet revealing the putative emission regions for recently detected y-rays from the core region by Fermi/LAT. Conclusions. We resolve the innermost structure of the milliarcsecond scale jet and counter jet system of Cen A into discrete components. The simultaneous observations at two frequencies provide the highest resolved spectral index map of an AGN jet allowing us to identify up to four possible sites as the origin of the high energy emission. Key words. galaxies: active galaxies: individual (Centaurus A, NGC 5128) - galaxies: jets - techniques: high angular resolution

  10. Physician Dual Practice: A Descriptive Mapping Review of Literature.

    PubMed

    Moghri, Javad; Arab, Mohammad; Rashidian, Arash; Akbari Sari, Ali

    2016-03-01

    Physician dual practice is a common phenomenon in almost all countries throughout the world, which could potential impacts on access, equity and quality of services. This paper aims to review studies in physician dual practice and categorize them in order to their main objectives and purposes. Comprehensive literature searches were undertaken in order to obtain main papers and documents in the field of physician dual practice. Systematic searches in Medline and Embase from 1960 to 2013, and general searches in some popular search engines were carried out in this way. After that, descriptive mapping review methods were utilized to categorize eligible studies in this area. The searches obtained 404 titles, of which 81 full texts were assessed. Finally, 24 studies were eligible for inclusion in our review. These studies were categorized into four groups - "motivation and forces behind dual practice", "consequences of dual practice", "dual practice Policies and their impacts", and "other studies" - based on their main objectives. Our findings showed a dearth of scientifically reliable literature in some areas of dual practice, like the prevalence of the phenomenon, the real consequences of it, and the impacts of the implemented policy measures. Rigorous empirical and evaluative studies should be designed to detect the real consequences of DP and assess the effects of interventions and regulations, which governments have implemented in this field.

  11. Health care utilization among Medicare-Medicaid dual eligibles: a count data analysis.

    PubMed

    Moon, Sangho; Shin, Jaeun

    2006-04-05

    Medicare-Medicaid dual eligibles are the beneficiaries of both Medicare and Medicaid. Dual eligibles satisfy the eligibility conditions for Medicare benefit. Dual eligibles also qualify for Medicaid because they are aged, blind, or disabled and meet the income and asset requirements for receiving Supplement Security Income (SSI) assistance. The objective of this study is to explore the relationship between dual eligibility and health care utilization among Medicare beneficiaries. The household component of the nationally representative Medical Expenditure Panel Survey (MEPS) 1996-2000 is used for the analysis. Total 8,262 Medicare beneficiaries are selected from the MEPS data. The Medicare beneficiary sample includes individuals who are covered by Medicare and do not have private health insurance during a given year. Zero-inflated negative binomial (ZINB) regression model is used to analyse the count data regarding health care utilization: office-based physician visits, hospital inpatient nights, agency-sponsored home health provider days, and total dental visits. Dual eligibility is positively correlated with the likelihood of using hospital inpatient care and agency-sponsored home health services and the frequency of agency-sponsored home health days. Frequency of dental visits is inversely associated with dual eligibility. With respect to racial differences, dually eligible Afro-Americans use more office-based physician and dental services than white duals. Asian duals use more home health services than white duals at the 5% statistical significance level. The dual eligibility programs seem particularly beneficial to Afro-American duals. Dual eligibility has varied impact on health care utilization across service types. More utilization of home healthcare among dual eligibles appears to be the result of delayed realization of their unmet healthcare needs under the traditional Medicare-only program rather than the result of overutilization in response to the

  12. Dual porosity gas evolving electrode

    DOEpatents

    Townsend, C.W.

    1994-11-15

    A dual porosity electrode is described for use in thermoelectrochemical systems where simultaneous transport of gas and liquid into and/or out of the electrode is required. The electrode includes catalytic electrode particles having diameters ranging from about 25 to 100 angstroms. The catalytic electrode particles are anchored to a support network in clusters which have internal pores ranging in size from 25 to 100 angstroms. The pores between the clusters range in size from between about 1 to 20 microns. A method for making the dual porosity electrodes is also disclosed.

  13. Dual porosity gas evolving electrode

    DOEpatents

    Townsend, Carl W.

    1994-01-01

    A dual porosity electrode for use in thermoelectrochemical systems where simultaneous transport of gas and liquid into and/or out of the electrode is required. The electrode includes catalytic electrode particles having diameters ranging from about 25 to 100 angstroms. The catalytic electrode particles are anchored to a support network in clusters which have internal pores ranging in size from 25 to 100 angstroms. The pores between the clusters range in size from between about 1 to 20 microns. A method for making the dual porosity electrodes is also disclosed.

  14. 92 GHz dual-polarized integrated horn antennas

    NASA Technical Reports Server (NTRS)

    Ali-Ahmad, Walid Y.; Rebeiz, Gabriel M.

    1991-01-01

    A dual-polarized two-dimensional imaging array was designed for millimeter-wave applications. The dual-polarized design consists of two dipoles perpendicular to each other and suspended on the same membrane inside a pyramidal cavity etched in silicon. The dual-polarized antenna is fully monolithic with room available for processing electronics. The IF or video signals are taken out through a novel bias and feeding structure. The measured polarization isolation is better than 20 dB at 92 GHz, and the orthogonal channels show identical far-field patterns. The antenna is well suited for millimeter-wave polarimetric synthetic-aperture radars (SARs) and high-efficiency balanced-mixer receivers.

  15. Truncated Dual-Cap Nucleation Site Development

    NASA Technical Reports Server (NTRS)

    Matson, Douglas M.; Sander, Paul J.

    2012-01-01

    During heterogeneous nucleation within a metastable mushy-zone, several geometries for nucleation site development must be considered. Traditional spherical dual cap and crevice models are compared to a truncated dual cap to determine the activation energy and critical cluster growth kinetics in ternary Fe-Cr-Ni steel alloys. Results of activation energy results indicate that nucleation is more probable at grain boundaries within the solid than at the solid-liquid interface.

  16. Immigrants and Suffrage: Adding to the Discourse by Integrating State versus National Citizenship, Dual Domestic Residency, and Dual Citizenship

    ERIC Educational Resources Information Center

    Garcia, John A.

    2012-01-01

    This article builds upon the literature on immigrants and the vote by focusing on three legal and democratic principles: state versus national citizenship, dual domestic residency, and globalization/dual citizenship. It first delineates the discretion and powers that states can utilize to establish suffrage rights. The article next develops…

  17. Enhanced contrast ratio and viewing angle of polymer-stabilized liquid crystal via refractive index matching between liquid crystal and polymer network.

    PubMed

    Lee, Ji-Hoon; Lee, Jung Jin; Lim, Young Jin; Kundu, Sudarshan; Kang, Shin-Woong; Lee, Seung Hee

    2013-11-04

    Long standing electro-optic problems of a polymer-dispersed liquid crystal (PDLC) such as low contrast ratio and transmittances decrease in oblique viewing angle have been challenged with a mixture of dual frequency liquid crystal (DFLC) and reactive mesogen (RM). The DFLC and RM molecules were vertically aligned and then photo-polymerized using a UV light. At scattering state under 50 kHz electric field, DFLC was switched to planar state, giving greater extraordinary refractive index than the normal PDLC cell. Consequently, the scattering intensity and the contrast ratio were increased compared to the conventional PDLC cell. At transparent state under 1 kHz electric field, the extraordinary refractive index of DFLC was simultaneously matched with the refractive index of vertically aligned RM so that the light scattering in oblique viewing angles was minimized, giving rise to high transmittance in all viewing angles.

  18. Postmortem validation of breast density using dual-energy mammography

    PubMed Central

    Molloi, Sabee; Ducote, Justin L.; Ding, Huanjun; Feig, Stephen A.

    2014-01-01

    Purpose: Mammographic density has been shown to be an indicator of breast cancer risk and also reduces the sensitivity of screening mammography. Currently, there is no accepted standard for measuring breast density. Dual energy mammography has been proposed as a technique for accurate measurement of breast density. The purpose of this study is to validate its accuracy in postmortem breasts and compare it with other existing techniques. Methods: Forty postmortem breasts were imaged using a dual energy mammography system. Glandular and adipose equivalent phantoms of uniform thickness were used to calibrate a dual energy basis decomposition algorithm. Dual energy decomposition was applied after scatter correction to calculate breast density. Breast density was also estimated using radiologist reader assessment, standard histogram thresholding and a fuzzy C-mean algorithm. Chemical analysis was used as the reference standard to assess the accuracy of different techniques to measure breast composition. Results: Breast density measurements using radiologist reader assessment, standard histogram thresholding, fuzzy C-mean algorithm, and dual energy were in good agreement with the measured fibroglandular volume fraction using chemical analysis. The standard error estimates using radiologist reader assessment, standard histogram thresholding, fuzzy C-mean, and dual energy were 9.9%, 8.6%, 7.2%, and 4.7%, respectively. Conclusions: The results indicate that dual energy mammography can be used to accurately measure breast density. The variability in breast density estimation using dual energy mammography was lower than reader assessment rankings, standard histogram thresholding, and fuzzy C-mean algorithm. Improved quantification of breast density is expected to further enhance its utility as a risk factor for breast cancer. PMID:25086548

  19. Postmortem validation of breast density using dual-energy mammography

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Molloi, Sabee, E-mail: symolloi@uci.edu; Ducote, Justin L.; Ding, Huanjun

    2014-08-15

    Purpose: Mammographic density has been shown to be an indicator of breast cancer risk and also reduces the sensitivity of screening mammography. Currently, there is no accepted standard for measuring breast density. Dual energy mammography has been proposed as a technique for accurate measurement of breast density. The purpose of this study is to validate its accuracy in postmortem breasts and compare it with other existing techniques. Methods: Forty postmortem breasts were imaged using a dual energy mammography system. Glandular and adipose equivalent phantoms of uniform thickness were used to calibrate a dual energy basis decomposition algorithm. Dual energy decompositionmore » was applied after scatter correction to calculate breast density. Breast density was also estimated using radiologist reader assessment, standard histogram thresholding and a fuzzy C-mean algorithm. Chemical analysis was used as the reference standard to assess the accuracy of different techniques to measure breast composition. Results: Breast density measurements using radiologist reader assessment, standard histogram thresholding, fuzzy C-mean algorithm, and dual energy were in good agreement with the measured fibroglandular volume fraction using chemical analysis. The standard error estimates using radiologist reader assessment, standard histogram thresholding, fuzzy C-mean, and dual energy were 9.9%, 8.6%, 7.2%, and 4.7%, respectively. Conclusions: The results indicate that dual energy mammography can be used to accurately measure breast density. The variability in breast density estimation using dual energy mammography was lower than reader assessment rankings, standard histogram thresholding, and fuzzy C-mean algorithm. Improved quantification of breast density is expected to further enhance its utility as a risk factor for breast cancer.« less

  20. The neural architecture of age-related dual-task interferences.

    PubMed

    Chmielewski, Witold X; Yildiz, Ali; Beste, Christian

    2014-01-01

    In daily life elderly adults exhibit deficits when dual-tasking is involved. So far these deficits have been verified on a behavioral level in dual-tasking. Yet, the neuronal architecture of these deficits in aging still remains to be explored especially when late-middle aged individuals around 60 years of age are concerned. Neuroimaging studies in young participants concerning dual-tasking were, among others, related to activity in middle frontal (MFG) and superior frontal gyrus (SFG) and the anterior insula (AI). According to the frontal lobe hypothesis of aging, alterations in these frontal regions (i.e., SFG and MFG) might be responsible for cognitive deficits. We measured brain activity using fMRI, while examining age-dependent variations in dual-tasking by utilizing the PRP (psychological refractory period) test. Behavioral data showed an increasing PRP effect in late-middle aged adults. The results suggest the age-related deteriorated performance in dual-tasking, especially in conditions of risen complexity. These effects are related to changes in networks involving the AI, the SFG and the MFG. The results suggest that different cognitive subprocesses are affected that mediate the observed dual-tasking problems in late-middle aged individuals.

  1. Economic Efficiency and Investment Timing for Dual Water Systems

    NASA Astrophysics Data System (ADS)

    Leconte, Robert; Hughes, Trevor C.; Narayanan, Rangesan

    1987-10-01

    A general methodology to evaluate the economic feasibility of dual water systems is presented. In a first step, a static analysis (evaluation at a single point in time) is developed. The analysis requires the evaluation of consumers' and producer's surpluses from water use and the capital cost of the dual (outdoor) system. The analysis is then extended to a dynamic approach where the water demand increases with time (as a result of a population increase) and where the dual system is allowed to expand. The model determines whether construction of a dual system represents a net benefit, and if so, what is the best time to initiate the system (corresponding to maximization of social welfare). Conditions under which an analytic solution is possible are discussed and results of an application are summarized (including sensitivity to different parameters). The analysis allows identification of key parameters influencing attractiveness of dual water systems.

  2. Dual-energy contrast-enhanced digital mammography: initial clinical results of a multireader, multicase study

    PubMed Central

    2012-01-01

    Introduction The purpose of this study was to compare the diagnostic accuracy of dual-energy contrast-enhanced digital mammography (CEDM) as an adjunct to mammography (MX) ± ultrasonography (US) with the diagnostic accuracy of MX ± US alone. Methods One hundred ten consenting women with 148 breast lesions (84 malignant, 64 benign) underwent two-view dual-energy CEDM in addition to MX and US using a specially modified digital mammography system (Senographe DS, GE Healthcare). Reference standard was histology for 138 lesions and follow-up for 12 lesions. Six radiologists from 4 institutions interpreted the images using high-resolution softcopy workstations. Confidence of presence (5-point scale), probability of cancer (7-point scale), and BI-RADS scores were evaluated for each finding. Sensitivity, specificity and ROC curve areas were estimated for each reader and overall. Visibility of findings on MX ± CEDM and MX ± US was evaluated with a Likert scale. Results The average per-lesion sensitivity across all readers was significantly higher for MX ± US ± CEDM than for MX ± US (0.78 vs. 0.71 using BIRADS, p = 0.006). All readers improved their clinical performance and the average area under the ROC curve was significantly superior for MX ± US ± CEDM than for MX ± US ((0.87 vs 0.83, p = 0.045). Finding visibility was similar or better on MX ± CEDM than MX ± US in 80% of cases. Conclusions Dual-energy contrast-enhanced digital mammography as an adjunct to MX ± US improves diagnostic accuracy compared to MX ± US alone. Addition of iodinated contrast agent to MX facilitates the visualization of breast lesions. PMID:22697607

  3. Exploring dual commitment among physician executives in managed care.

    PubMed

    Hoff, T J

    2001-01-01

    The growth of a medical management specialty is a significant event associated with managed care. Physician executives are lauded for their potential in bridging the clinical and managerial realms. They also serve as a countervailing force to help the medical profession and patients maintain a strong voice in healthcare decision making at the strategic level. However, little is known about their work loyalties. These attitudes are important to explore because they speak to whose interests physician executives consider and represent in their everyday management roles. If physician executives are to maximize their effectiveness in the healthcare workplace, both physicians and organizations must view them as credible sources of authority. This study examines organizational and professional commitment among a national sample of physician executives employed in managed care settings. Data used for the analysis come from a national survey conducted through the American College of Physician Executives in 1996. The findings support the notion that physician executives can and do express simultaneous loyalty to organizational and professional interests. This dual commitment is related to other work attitudes that contribute to success in the management role. In addition, it appears that situational factors increase the chances for dual commitment. These factors derive from a favorable work environment that includes both organizational and professional socialization in the management role. The results of the study are useful in specifying the training and socialization needs of physicians who wish to do management work. They also provide a rationale for collaboration between healthcare organizations and rank-and-file physicians aimed at cultivating physician executives who are credible leaders within the healthcare system.

  4. Coherent cavity-enhanced dual-comb spectroscopy.

    PubMed

    Fleisher, Adam J; Long, David A; Reed, Zachary D; Hodges, Joseph T; Plusquellic, David F

    2016-05-16

    Dual-comb spectroscopy allows for the rapid, multiplexed acquisition of high-resolution spectra without the need for moving parts or low-resolution dispersive optics. This method of broadband spectroscopy is most often accomplished via tight phase locking of two mode-locked lasers or via sophisticated signal processing algorithms, and therefore, long integration times of phase coherent signals are difficult to achieve. Here we demonstrate an alternative approach to dual-comb spectroscopy using two phase modulator combs originating from a single continuous-wave laser capable of > 2 hours of coherent real-time averaging. The dual combs were generated by driving the phase modulators with step-recovery diodes where each comb consisted of > 250 teeth with 203 MHz spacing and spanned > 50 GHz region in the near-infrared. The step-recovery diodes are passive devices that provide low-phase-noise harmonics for efficient coupling into an enhancement cavity at picowatt optical powers. With this approach, we demonstrate the sensitivity to simultaneously monitor ambient levels of CO2, CO, HDO, and H2O in a single spectral region at a maximum acquisition rate of 150 kHz. Robust, compact, low-cost and widely tunable dual-comb systems could enable a network of distributed multiplexed optical sensors.

  5. Dual AAV Vectors for Stargardt Disease.

    PubMed

    Trapani, Ivana

    2018-01-01

    Stargardt disease (STGD1), due to mutations in the large ABCA4 gene, is the most common inherited macular degeneration in humans. Attempts at developing gene therapy approaches for treatment of STGD1 are currently ongoing. Among all the vectors available for gene therapy of inherited retinal diseases, those based on adeno-associated viruses (AAV) are the most promising given the efficacy shown in various animal models and their excellent safety profile in humans, as confirmed in many ongoing clinical trials. However, one of the main obstacles for the use of AAV is their limited effective packaging capacity of about 5 kb. Taking advantage of the AAV genome's ability to concatemerize , others and we have recently developed dual AAV vectors to overcome this limit. We tested dual AAV vectors for ABCA4 delivery, and found that they transduce efficiently both mouse and pig photoreceptors , and rescue the Abca4-/- mouse retinal phenotype, indicating their potential for gene therapy of STGD1. This chapter details how we designed dual AAV vectors for the delivery of the ABCA4 gene and describes the techniques that can be explored to evaluate dual AAV transduction efficiency in vitro and in the retina, and their efficacy in the mouse model of STGD1.

  6. Coherent cavity-enhanced dual-comb spectroscopy

    PubMed Central

    Fleisher, Adam J.; Long, David A.; Reed, Zachary D.; Hodges, Joseph T.; Plusquellic, David F.

    2016-01-01

    Dual-comb spectroscopy allows for the rapid, multiplexed acquisition of high-resolution spectra without the need for moving parts or low-resolution dispersive optics. This method of broadband spectroscopy is most often accomplished via tight phase locking of two mode-locked lasers or via sophisticated signal processing algorithms, and therefore, long integration times of phase coherent signals are difficult to achieve. Here we demonstrate an alternative approach to dual-comb spectroscopy using two phase modulator combs originating from a single continuous-wave laser capable of > 2 hours of coherent real-time averaging. The dual combs were generated by driving the phase modulators with step-recovery diodes where each comb consisted of > 250 teeth with 203 MHz spacing and spanned > 50 GHz region in the near-infrared. The step-recovery diodes are passive devices that provide low-phase-noise harmonics for efficient coupling into an enhancement cavity at picowatt optical powers. With this approach, we demonstrate the sensitivity to simultaneously monitor ambient levels of CO2, CO, HDO, and H2O in a single spectral region at a maximum acquisition rate of 150 kHz. Robust, compact, low-cost and widely tunable dual-comb systems could enable a network of distributed multiplexed optical sensors. PMID:27409866

  7. Dual-band beacon experiment over Southeast Asia for ionospheric irregularity analysis

    NASA Astrophysics Data System (ADS)

    Watthanasangmechai, K.; Yamamoto, M.; Saito, A.; Saito, S.; Maruyama, T.; Tsugawa, T.; Nishioka, M.

    2013-12-01

    An experiment of dual-band beacon over Southeast Asia was started in March 2012 in order to capture and analyze ionospheric irregularities in equatorial region. Five GNU Radio Beacon Receivers (GRBRs) were aligned along 100 degree geographic longitude. The distances between the stations reach more than 500 km. The field of view of this observational network covers +/- 20 degree geomagnetic latitude including the geomagnetic equator. To capture ionospheric irregularities, the absolute TEC estimation technique was developed. The two-station method (Leitinger et al., 1975) is generally accepted as a suitable method to estimate TEC offsets of dual-band beacon experiment. However, the distances between the stations directly affect on the robustness of the technique. In Southeast Asia, the observational network is too sparse to attain a benefit of the classic two-station method. Moreover, the least-squares approch used in the two-station method tries too much to adjust the small scales of the TEC distribution which are the local minima. We thus propose a new technique to estimate the TEC offsets with the supporting data from absolute GPS-TEC from local GPS receivers and the ionospheric height from local ionosondes. The key of the proposed technique is to utilize the brute-force technique with weighting function to find the TEC offset set that yields a global minimum of RMSE in whole parameter space. The weight is not necessary when the TEC distribution is smooth, while it significantly improves the TEC estimation during the ESF events. As a result, the latitudinal TEC shows double-hump distribution because of the Equatorial Ionization Anomaly (EIA). In additions, the 100km-scale fluctuations from an Equatorial Spread F (ESF) are captured at night time in equinox seasons. The plausible linkage of the meridional wind with triggering of ESF is under invatigating and will be presented. The proposed method is successful to estimate the latitudinal TEC distribution from dual

  8. Dual Credit: Creating Career and Work Possibilities for Canadian Youth

    ERIC Educational Resources Information Center

    Watt-Malcolm, Bonnie

    2011-01-01

    In this article, I investigated the problems that educators are addressing with dual credit initiatives and consider tensions that have limited the seamless implementation of dual credit programming. Stakeholder representatives clearly identified common resources and support required to sustain their dual credit programs. Study participants noted…

  9. Formation of Offset and Dual Active Galactic Nuclei

    NASA Astrophysics Data System (ADS)

    Barrows, Scott; Comerford, Julia M.; Greene, Jenny E.

    2018-06-01

    Galaxy mergers are effective mechanisms for triggering accretion onto supermassive black holes (SMBHs) and thereby powering active galactic nuclei (AGN). In the merger scenario, when the SMBH from only one galaxy is accreting we observe a spatially offset AGN, and when the SMBHs from both galaxies are accreting we observe a dual AGN. Understanding the merger conditions that lead to the formation of offset AGN versus dual AGN is fundamental to informing models of hierarchical SMBH growth and the physics leading to the accretion of matter onto SMBHs. However, while the role of galaxy mergers for AGN triggering has been well-studied, the efficiency with which these events trigger offset AGN versus dual AGN is currently unclear. One reason for this gap in knowledge can be attributed to the observational difficulties in distinguishing between offset and dual AGN since doing so requires high spatial resolution, especially in the small separation regime where merger-driven AGN triggering is most likely to occur. To overcome this hurdle, we have utilized the spatial resolution of the Chandra X-ray Observatory to develop a unique sample of AGN hosted by late-stage galaxy mergers. Moreover, we have recently acquired Hubble Space Telescope imaging for a subset of these systems to examine the role that their merger morphologies play in SMBH growth and the formation of offset and dual AGN. We find that offset AGN are predominately found in minor mergers, whereas dual AGN are usually hosted by major mergers and galaxies with large morphological asymmetries. Furthermore, in both offset and dual AGN, the rate of SMBH growth increases toward more major mergers and larger morphological asymmetries. These results are in agreement with numerical simulations predicting that merger morphology is a relevant parameter governing SMBH merger-driven growth, and these results are the first to observationally confirm these trends at small pair separations.

  10. Adolescents and Dual Diagnosis in a Psychiatric Emergency Service.

    PubMed

    Matali, José Luis; Andión, Oscar; Pardo, Marta; Iniesta, Raquel; Serrano, Eduard; San, Luis

    2016-03-02

    In recent years, both the prevalence of drug use and related child and adolescent psychiatric emergencies have risen sharply. There are few studies about the impact on child and adolescent emergency services. This study has a twofold aim. The first is to describe the prevalence of substance use disorders, mental disorders and dual diagnosis (substance use problems plus mental disorder) in adolescents in psychiatric emergency service. The second is to analyze clinical and healthcare differences between patients with dual diagnosis and patients with a mental disorder without substance use disorder.We retrospectively reviewed 4012 discharge forms for emergencies treated at the psychiatric emergency department during the period 2007-2009. We obtained a sample of 1795 visits. This sample was divided into two groups: the dual diagnosis group (n = 477) and the psychiatric disorder group (n = 1318).The dual diagnosis group accounted for 26.5% of psychiatric emergencies analyzed. Compared to the psychiatric disorder group,the dual diagnosis group had significantly more conduct disorders, social problems, involuntariness in the visit, less hospital admissions and less connection with the healthcare network.Adolescents with a dual diagnosis account for a high percentage of visits at child and adolescent psychiatric emergency services. This patient group requires specialized care both at emergency services and in specific units. Accordingly, these units should play a triple role when handling dual diagnosis: detection, brief treatment and referral to a specialised unit.

  11. Dual Learning Processes in Interactive Skill Acquisition

    ERIC Educational Resources Information Center

    Fu, Wai-Tat; Anderson, John R.

    2008-01-01

    Acquisition of interactive skills involves the use of internal and external cues. Experiment 1 showed that when actions were interdependent, learning was effective with and without external cues in the single-task condition but was effective only with the presence of external cues in the dual-task condition. In the dual-task condition, actions…

  12. Dual-Chamber/Dual-Anode Proportional Counter Incorporating an Intervening Thin-Foil Solid Neutron Converter

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Boatner, Lynn A; Neal, John S; Blackston, Matthew A

    2012-01-01

    A dual-chamber/dual-anode gas proportional counter utilizing thin solid 6LiF or 10B neutron converters coated on a 2-micon-thick Mylar film that is positioned between the two counter chambers and anodes has been designed, fabricated, and tested using a variety of fill gases including naturally abundant helium. In this device, neutron conversion products emitted from both sides of the coated converter foil are detected rather than having half of the products absorbed in the wall of a conventional tube type counter where the solid neutron converter is deposited on the tube wall. Geant4-based radiation transport calculations were used to determine the optimummore » neutron converter coating thickness for both isotopes. Solution methods for applying these optimized-thickness coatings on a Mylar film were developed that were carried out at room temperature without any specialized equipment and that can be adapted to standard coating methods such as silk screen or ink jet printing. The performance characteristics of the dual-chamber/dual-anode neutron detector were determined for both types of isotopically enriched converters. The experimental performance of the 6LiF converter-based detector was described well by modeling results from Geant4. Additional modeling studies of multiple-foil/multiple-chamber/anode configurations addressed the basic issue of the relatively longer absorption range of neutrons versus the shorter range of the conversion products for 6LiF and 10B. Combined with the experimental results, these simulations indicate that a high-performance neutron detector can be realized in a single device through the application of these multiple-foil/solid converter, multiple-chamber detector concepts.« less

  13. Longitudinal effects of bilingualism on dual-tasking

    PubMed Central

    Josefsson, Maria; Marsh, John E.; Hansson, Patrik; Ljungberg, Jessica K.

    2017-01-01

    An ongoing debate surrounds whether bilinguals outperform monolinguals in tests of executive processing. The aim of this study was to investigate if there are long-term (10 year) bilingual advantages in executive processing, as indexed by dual-task performance, in a sample that were 40–65 years at baseline. The bilingual (n = 24) and monolingual (n = 24) participants were matched on age, sex, education, fluid intelligence, and study sample. Participants performed free-recall for a 12-item list in three dual-task settings wherein they sorted cards either during encoding, retrieval, or during both encoding and retrieval of the word-list. Free recall without card sorting was used as a reference to compute dual-task costs. The results showed that bilinguals significantly outperformed monolinguals when they performed card-sorting during both encoding and retrieval of the word-list, the condition that presumably placed the highest demands on executive functioning. However, dual-task costs increased over time for bilinguals relative to monolinguals, a finding that is possibly influenced by retirement age and limited use of second language in the bilingual group. PMID:29281654

  14. 20 CFR 225.13 - Social Security Earnings Dual Benefit PIA.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 1 2011-04-01 2011-04-01 false Social Security Earnings Dual Benefit PIA... Spouse Annuities § 225.13 Social Security Earnings Dual Benefit PIA. (a) General. The Social Security... certain eligibility requirements as described in part 216 of this chapter. The Social Security Dual...

  15. 20 CFR 225.13 - Social Security Earnings Dual Benefit PIA.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 20 Employees' Benefits 1 2014-04-01 2012-04-01 true Social Security Earnings Dual Benefit PIA. 225... Spouse Annuities § 225.13 Social Security Earnings Dual Benefit PIA. (a) General. The Social Security... certain eligibility requirements as described in part 216 of this chapter. The Social Security Dual...

  16. 20 CFR 225.13 - Social Security Earnings Dual Benefit PIA.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 1 2013-04-01 2012-04-01 true Social Security Earnings Dual Benefit PIA. 225... Spouse Annuities § 225.13 Social Security Earnings Dual Benefit PIA. (a) General. The Social Security... certain eligibility requirements as described in part 216 of this chapter. The Social Security Dual...

  17. 20 CFR 225.13 - Social Security Earnings Dual Benefit PIA.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 1 2012-04-01 2012-04-01 false Social Security Earnings Dual Benefit PIA... Spouse Annuities § 225.13 Social Security Earnings Dual Benefit PIA. (a) General. The Social Security... certain eligibility requirements as described in part 216 of this chapter. The Social Security Dual...

  18. 20 CFR 225.13 - Social Security Earnings Dual Benefit PIA.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false Social Security Earnings Dual Benefit PIA... Spouse Annuities § 225.13 Social Security Earnings Dual Benefit PIA. (a) General. The Social Security... certain eligibility requirements as described in part 216 of this chapter. The Social Security Dual...

  19. Contextual representations increase analogue traumatic intrusions: evidence against a dual-representation account of peri-traumatic processing.

    PubMed

    Pearson, David G

    2012-12-01

    Information processing accounts of post-traumatic stress disorder (PTSD) state that intrusive memories emerge due to a lack of integration between perceptual and contextual trauma representations in autobiographical memory. This hypothesis was tested experimentally using an analogue trauma paradigm in which participants viewed an aversive film designed to elicit involuntary recollections. Participants viewed scenes from the film either paired with contextual information or with the contextual information omitted. After viewing the film participants were asked to record for one week any involuntary intrusions for the film using a provided intrusions diary. The results revealed a significant increase in analogue intrusions for the film when viewed with contextual information in comparison to when the film was viewed with the contextual information omitted. In contrast there was no effect of contextual information on valence ratings or voluntary memory for the film, or on the reported vividness and emotionality of the intrusions. The analogue trauma paradigm may have failed to reproduce the effect of extreme stress on encoding that is postulated to occur during PTSD. The findings have potential implications for trauma intervention as they suggest that the contextual understanding of a scene during encoding can be integral to the subsequent occurrence of traumatic intrusions. The pattern of results found in the study are inconsistent with dual-representation accounts of intrusive memory formation, and instead provide new evidence that contextual representations play a casual role in increasing the frequency of involuntary intrusions for traumatic material. Copyright © 2012 Elsevier Ltd. All rights reserved.

  20. Working Memory Training Improves Dual-Task Performance on Motor Tasks.

    PubMed

    Kimura, Takehide; Kaneko, Fuminari; Nagahata, Keita; Shibata, Eriko; Aoki, Nobuhiro

    2017-01-01

    The authors investigated whether working memory training improves motor-motor dual-task performance consisted of upper and lower limb tasks. The upper limb task was a simple reaction task and the lower limb task was an isometric knee extension task. 45 participants (age = 21.8 ± 1.6 years) were classified into a working memory training group (WM-TRG), dual-task training group, or control group. The training duration was 2 weeks (15 min, 4 times/week). Our results indicated that working memory capacity increased significantly only in the WM-TRG. Dual-task performance improved in the WM-TRG and dual-task training group. Our study provides the novel insight that working memory training improves dual-task performance without specific training on the target motor task.

  1. When parsimony is not enough: Considering dual processes and dual levels of influence in sexual decision making

    PubMed Central

    Rendina, H. Jonathon

    2015-01-01

    The literature on sexual decision making that has been used to understand behaviors relevant to HIV and STI risk has relied primarily on cognitive antecedents of behavior. In contrast, several prominent models of decision making outside of the sexual behavior literature rely on dual process models, in which both affective and cognitive processing are considered important precursors to behavior. Moreover, much of the literature on sexual behavior utilizes individual-level traits and characteristics to predict aggregated sexual behavior, despite decision making itself being a situational or event-level process. This paper proposes a framework for understanding sexual decision making as the result of dual processes (affective and cognitive) operating at dual level of influence (individual and situational). Finally, the paper ends with a discussion of the conceptual and methodological benefits and challenges to its use and future directions for research. PMID:26168978

  2. Dual-Phase Nozzle Flow.

    DTIC Science & Technology

    1982-10-01

    peowti ulliy klei =PodUaWU THESIS DUAL-PHASE NO ZZL FLOW :hcras C. Holi. Jr. Oco’ber 934’ Thesis Advisor: J. F. SlIj=kv Ap:roved _"o~r :zubiic releasc...REPORT NUMBER ILGOVT ACCESSION NO. I. MECIP1EMYS CATALOG NUNSI 3 A. TTLE Old WIM110)S. TYPE or mrEowR A PERIOD COVERED Master’s Thesis ; Dual-Phase Nozzle...ALPUS , Aml A As AT , ’A rF2 fl’Q 2 05 dETAS 181 T AM Si. T 1 AS J!’𔃻 3 c * I CA,; I CA ;A a ZA c1. 1 B SL z.1J 4 CBG1 *CAL *CASE * b. a C𔃾 ; -* U.9 CC

  3. Accuracy of Dual-Energy Virtual Monochromatic CT Numbers: Comparison between the Single-Source Projection-Based and Dual-Source Image-Based Methods.

    PubMed

    Ueguchi, Takashi; Ogihara, Ryota; Yamada, Sachiko

    2018-03-21

    To investigate the accuracy of dual-energy virtual monochromatic computed tomography (CT) numbers obtained by two typical hardware and software implementations: the single-source projection-based method and the dual-source image-based method. A phantom with different tissue equivalent inserts was scanned with both single-source and dual-source scanners. A fast kVp-switching feature was used on the single-source scanner, whereas a tin filter was used on the dual-source scanner. Virtual monochromatic CT images of the phantom at energy levels of 60, 100, and 140 keV were obtained by both projection-based (on the single-source scanner) and image-based (on the dual-source scanner) methods. The accuracy of virtual monochromatic CT numbers for all inserts was assessed by comparing measured values to their corresponding true values. Linear regression analysis was performed to evaluate the dependency of measured CT numbers on tissue attenuation, method, and their interaction. Root mean square values of systematic error over all inserts at 60, 100, and 140 keV were approximately 53, 21, and 29 Hounsfield unit (HU) with the single-source projection-based method, and 46, 7, and 6 HU with the dual-source image-based method, respectively. Linear regression analysis revealed that the interaction between the attenuation and the method had a statistically significant effect on the measured CT numbers at 100 and 140 keV. There were attenuation-, method-, and energy level-dependent systematic errors in the measured virtual monochromatic CT numbers. CT number reproducibility was comparable between the two scanners, and CT numbers had better accuracy with the dual-source image-based method at 100 and 140 keV. Copyright © 2018 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

  4. Estimation of Land Surface Energy Balance Using Satellite Data of Spatial Reduced Resolution

    NASA Astrophysics Data System (ADS)

    Vintila, Ruxandra; Radnea, Cristina; Savin, Elena; Poenaru, Violeta

    2010-12-01

    The paper presents preliminary results concerning the monitoring at national level of several geo-biophysical variables retrieved by remote sensing, in particular those related to drought or aridisation. The study, which is in progress, represents also an exercise for to the implementation of a Land Monitoring Core Service for Romania, according to the Kopernikus Program and in compliance with the INSPIRE Directive. The SEBS model has been used to retrieve land surface energy balance variables, such as turbulent heat fluxes, evaporative fraction and daily evaporation, based on three information types: (1) surface albedo, emissivity, temperature, fraction of vegetation cover (fCover), leaf area index (LAI) and vegetation height; (2) air pressure, temperature, humidity and wind speed at the planetary boundary layer (PBL) height; (3) downward solar radiation and downward longwave radiation. AATSR and MERIS archived reprocessed images have provided several types of information. Thus, surface albedo, emissivity, and land surface temperature have been retrieved from AATSR, while LAI and fCover have been estimated from MERIS. The vegetation height has been derived from CORINE Land Cover and PELCOM Land Use databases, while the meteorological information at the height of PBL have been estimated from the measurements provided by the national weather station network. Other sources of data used during this study have been the GETASSE30 digital elevation model with 30" spatial resolution, used for satellite image orthorectification, and the SIGSTAR-200 geographical information system of soil resources of Romania, used for water deficit characterisation. The study will continue by processing other AATSR and MERIS archived images, complemented by the validation of SEBS results with ground data collected on the most important biomes for Romania at various phenological stages, and the transformation of evaporation / evapotranspiration into a drought index using the soil texture

  5. Major depressive disorder and impulsive reactivity to emotion: toward a dual-process view of depression.

    PubMed

    Carver, Charles S; Johnson, Sheri L; Joormann, Jutta

    2013-09-01

    Dual-process theories of behaviour have been used to suggest that vulnerability to depression involves elevated reactivity to emotions. This study tests that idea, examining self-reported reactivity. Comparison between persons with at least one lifetime episode of major depressive disorder (lifetime MDD) and those without this diagnosis, controlling for symptoms of alcohol use (a potential externalizing confound) and current symptoms of depression (a potential state-dependent confound). Undergraduates (N = 120) completed a clinical interview to diagnose lifetime MDD and a series of self-reports bearing on diverse aspects of self-control, including reactivity to emotion. Thirty-four people were diagnosed with lifetime MDD; 86 did not meet criteria for MDD. The groups were then compared on three factors underlying the scales assessing self-control. The MDD group had higher scores than controls on the two factors that reflect impulsive reactivity to diverse emotions, including emotions that are positive in valence. These effects were not explained by associations with either externalizing symptoms or current depressive symptoms. Reflexive reactivity to emotions characterizes depression, in addition to some externalizing problems, and it may deserve study as a potential trans-diagnostic feature. Reflexive reactivity to emotions characterizes persons diagnosed with major depressive disorder. Findings suggest desirability of focusing treatment partly on management of reflexive reactions to emotions. Measures were self-reports, rather than behavioural responses to emotions. © 2013 The British Psychological Society.

  6. UWB dual burst transmit driver

    DOEpatents

    Dallum, Gregory E [Livermore, CA; Pratt, Garth C [Discovery Bay, CA; Haugen, Peter C [Livermore, CA; Zumstein, James M [Livermore, CA; Vigars, Mark L [Livermore, CA; Romero, Carlos E [Livermore, CA

    2012-04-17

    A dual burst transmitter for ultra-wideband (UWB) communication systems generates a pair of precisely spaced RF bursts from a single trigger event. An input trigger pulse produces two oscillator trigger pulses, an initial pulse and a delayed pulse, in a dual trigger generator. The two oscillator trigger pulses drive a gated RF burst (power output) oscillator. A bias driver circuit gates the RF output oscillator on and off and sets the RF burst packet width. The bias driver also level shifts the drive signal to the level that is required for the RF output device.

  7. 46 CFR 111.05-29 - Dual voltage direct current systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Dual voltage direct current systems. Each dual voltage direct current system must have a suitably sensitive ground detection system which indicates current in the ground connection, has a range of at least... 46 Shipping 4 2010-10-01 2010-10-01 false Dual voltage direct current systems. 111.05-29 Section...

  8. 46 CFR 111.05-29 - Dual voltage direct current systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Dual voltage direct current systems. Each dual voltage direct current system must have a suitably sensitive ground detection system which indicates current in the ground connection, has a range of at least... 46 Shipping 4 2011-10-01 2011-10-01 false Dual voltage direct current systems. 111.05-29 Section...

  9. Dual redundant arm system operational quality measures and their applications - Dynamic measures

    NASA Technical Reports Server (NTRS)

    Lee, Sukhan; Kim, Sungbok

    1990-01-01

    Dual-arm dynamic operation quality measures are presented which quantify the efficiency and capability of generating Cartesian accelerations by two cooperative arms based on the analysis of dual-arm dynamic interactions. Dual-arm dynamic manipulability is defined as the efficiency of generating Cartesian accelerations under the dynamic and kinematic interactions between individual arms and an object under manipulation. The analysis of dual-arm dynamic interactions is based on the so-called Cartesian space agent model of an arm, which represents an individual arm as a force source acting upon a point mass with the effective Cartesian space arm dynamics and an environment or an object under manipulation. The Cartesian space agent model of an arm makes it possible to derive the dynamic and kinematic constraints involved in the transport, assembly and grasping modes of dual-arm cooperation. A task-oriented operational quality measure, (TOQd) is defined by evaluating dual-arm dynamic manipulability in terms of given task requirements. TOQd is used in dual-arm joint configuration optimization. Simulation results are shown. A complete set of forward dynamic equations for a dual-arm system is derived, and dual-arm dynamic operational quality measures for various modes of dual-arm cooperation allowing sliding contacts are established.

  10. On the dual equivalence of the self-dual and topologically massive /B∧F models coupled to dynamical fermionic matter

    NASA Astrophysics Data System (ADS)

    Menezes, R.; Nascimento, J. R. S.; Ribeiro, R. F.; Wotzasek, C.

    2002-06-01

    We study the equivalence between the /B∧F self-dual (SDB∧F) and the /B∧F topologically massive (TMB∧F) models including the coupling to dynamical, U(1) charged fermionic matter. This is done through an iterative procedure of gauge embedding that produces the dual mapping. In the interactive cases, the minimal coupling adopted for both vector and tensor fields in the self-dual representation is transformed into a non-minimal magnetic like coupling in the topologically massive representation but with the currents swapped. It is known that to establish this equivalence a current-current interaction term is needed to render the matter sector unchanged. We show that both terms arise naturally from the embedding procedure.

  11. Simultaneous measurement of temperature and emissivity of lunar regolith simulant using dual-channel millimeter-wave radiometry

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    McCloy, J. S.; Sundaram, S. K.; Matyas, J.

    Millimeter wave (MMW) radiometry can be used for simultaneous measurement of emissivity and temperature of materials under extreme environments (high temperature, pressure, and corrosive environments). The state-of-the-art dual channel MMW passive radiometer with active interferometric capabilities at 137 GHz described here allows for radiometric measurements of sample temperature and emissivity up to at least 1600 °C with simultaneous measurement of sample surface dynamics. These capabilities have been used to demonstrate dynamic measurement of melting of powders of simulated lunar regolith and static measurement of emissivity of solid samples. The paper presents the theoretical background and basis for the dual-receiver system,more » describes the hardware in detail, and demonstrates the data analysis. Post-experiment analysis of emissivity versus temperature allows further extraction from the radiometric data of millimeter wave viewing beam coupling factors, which provide corroboratory evidence to the interferometric data of the process dynamics observed. Finally, these results show the promise of the MMW system for extracting quantitative and qualitative process parameters for industrial processes and access to real-time dynamics of materials behavior in extreme environments.« less

  12. Fringe formation in dual-hologram interferometry

    NASA Technical Reports Server (NTRS)

    Burner, A. W.

    1990-01-01

    Reference-fringe formation in nondiffuse dual-hologram interferometry is described by combining a first-order geometrical hologram treatment with interference fringes generated by two point sources. The first-order imaging relationships can be used to describe reference-fringe patterns for the geometry of the dual-hologram interferometry. The process can be completed without adjusting the two holograms when the reconstructing wavelength is less than the exposing wavelength, and the process is found to facilitate basic intereferometer adjustments.

  13. Dual-gate GaAs FET switches

    NASA Astrophysics Data System (ADS)

    Vorhaus, J. L.; Fabian, W.; Ng, P. B.; Tajima, Y.

    1981-02-01

    A set of multi-pole, multi-throw switch devices consisting of dual-gate GaAs FET's is described. Included are single-pole, single-throw (SPST), double-pole, double-throw (DPDT), and single-pole four-throw (SP4T) switches. Device fabrication and measurement techniques are discussed. The device models for these switches were based on an equivalent circuit of a dual-gate FET. The devices were found to have substantial gain in X-band and low Ku-band.

  14. Behavioral Assessment of Listening Effort Using a Dual-Task Paradigm.

    PubMed

    Gagné, Jean-Pierre; Besser, Jana; Lemke, Ulrike

    2017-01-01

    Published investigations ( n = 29) in which a dual-task experimental paradigm was employed to measure listening effort during speech understanding in younger and older adults were reviewed. A summary of the main findings reported in the articles is provided with respect to the participants' age-group and hearing status. Effects of different signal characteristics, such as the test modality, on dual-task outcomes are evaluated, and associations with cognitive abilities and self-report measures of listening effort are described. Then, several procedural issues associated with the use of dual-task experiment paradigms are discussed. Finally, some issues that warrant future research are addressed. The review revealed large variability in the dual-task experimental paradigms that have been used to measure the listening effort expended during speech understanding. The differences in experimental procedures used across studies make it difficult to draw firm conclusions concerning the optimal choice of dual-task paradigm or the sensitivity of specific paradigms to different types of experimental manipulations. In general, the analysis confirmed that dual-task paradigms have been used successfully to measure differences in effort under different experimental conditions, in both younger and older adults. Several research questions that warrant further investigation in order to better understand and characterize the intricacies of dual-task paradigms were identified.

  15. Behavioral Assessment of Listening Effort Using a Dual-Task Paradigm

    PubMed Central

    Besser, Jana; Lemke, Ulrike

    2017-01-01

    Published investigations (n = 29) in which a dual-task experimental paradigm was employed to measure listening effort during speech understanding in younger and older adults were reviewed. A summary of the main findings reported in the articles is provided with respect to the participants’ age-group and hearing status. Effects of different signal characteristics, such as the test modality, on dual-task outcomes are evaluated, and associations with cognitive abilities and self-report measures of listening effort are described. Then, several procedural issues associated with the use of dual-task experiment paradigms are discussed. Finally, some issues that warrant future research are addressed. The review revealed large variability in the dual-task experimental paradigms that have been used to measure the listening effort expended during speech understanding. The differences in experimental procedures used across studies make it difficult to draw firm conclusions concerning the optimal choice of dual-task paradigm or the sensitivity of specific paradigms to different types of experimental manipulations. In general, the analysis confirmed that dual-task paradigms have been used successfully to measure differences in effort under different experimental conditions, in both younger and older adults. Several research questions that warrant further investigation in order to better understand and characterize the intricacies of dual-task paradigms were identified. PMID:28091178

  16. Physical analysis of breast cancer using dual-source computed tomography

    NASA Astrophysics Data System (ADS)

    Kim, H. J.; Lee, H. K.; Cho, J. H.

    2014-12-01

    This study was aimed to analyze various physical characteristics of breast cancer using dual-source computed tomography (CT). A phantom study and a clinical trial were performed in order and a 64-multidetector CT device was used for the examinations. In the phantom study, single-source (SS) CT was set up with a conventional scanning condition that is usually applied for breast CT examination and implementation was done at tube voltage of 120 kVp. Dual-source CT acquired images by irradiating X-ray sources with fast switching between two kilovoltage settings (80 and 140 kVp). After scanning, Hounsfield Unit (HU) values and radiation doses in a region of interest were measured and analyzed. In the clinical trial, the HU values were measured and analyzed after single-source computed tomography (SSCT) and dual-source CT in patients diagnosed with breast cancer. Also, the tumor size measured by dual-source CT was compared with the actual tumor size. The phantom study determined that the tumor region was especially measured by dual-source CT, while nylon fiber and specks region were especially measured by SSCT. The radiation dose was high with dual-source CT. The clinical trial showed a higher HU value of cancerous regions when scanned by dual-source CT compared with SSCT.

  17. N = (2,0) self-dual non-Abelian tensor multiplet in D = 3 + 3 generates N = (1,1) self-dual systems in D = 2 + 2

    NASA Astrophysics Data System (ADS)

    Nishino, Hitoshi; Rajpoot, Subhash

    2018-03-01

    We formulate an N = (2 , 0) system in D = 3 + 3 dimensions consisting of a Yang-Mills (YM)-multiplet (ˆ μ ˆ IA, λˆI), a self-dual non-Abelian tensor multiplet (ˆ μ ˆ ν ˆ IB, χˆI ,φˆI), and an extra vector multiplet (C ˆ μ ˆ IC, ρˆI). We next perform the dimensional reductions of this system into D = 2 + 2, and obtain N = (1 , 1) systems with a self-dual YM-multiplet (AIμ ,λI), a self-dual tensor multiplet (BIμν , χI , φI), and an extra vector multiplet (CIμ , ρI). In D = 2 + 2, we reach two distinct theories: 'Theory-I' and 'Theory-II'. The former has the self-dual field-strength Hμν(+)I of CIμ already presented in our recent paper, while the latter has anti-self-dual field strength Hμν(-)I. As an application, we show that Theory-II actually generates supersymmetric-KdV equations in D = 1 + 1. Our result leads to a new conclusion that the D = 3 + 3 theory with non-Abelian tensor multiplet can be a 'Grand Master Theory' for self-dual multiplet and self-dual YM-multiplet in D = 2 + 2, that in turn has been conjectured to be the 'Master Theory' for all supersymmetric integrable theories in D ≤ 3.

  18. Philosophical aspects of dual use technologies.

    PubMed

    Pustovit, Svitlana V; Williams, Erin D

    2010-03-01

    The term dual use technologies refers to research and technology with the potential both to yield valuable scientific knowledge and to be used for nefarious purposes with serious consequences for public health or the environment. There are two main approaches to assessing dual use technologies: pragmatic and metaphysical. A pragmatic approach relies on ethical principles and norms to generate specific guidance and policy for dual use technologies. A metaphysical approach exhorts us to the deeper study of human nature, our intentions, goals, values ideals and social relations when considering dual use technology. Use of science and technology (S and T) is determined by two components of human nature: human intentions and choices. We have drawn a distinction between specific measures, goals and intentions with respect to technologies in order to show that moral judgment about technologies must precede their use. Understanding of our intentionality and values, and our moral ideals, as a measurable, tangible part of the real world is important for the prevention of any possible harm from S and T. In the context of dual use technologies, we stress the importance of three main understandings of human nature: vulnerability, responsibility and narrative identity. These can become a strong ontological "antidote" to technology's poisoning of modern man. Each new technology can be measured and compared with man's values, traditions and societal norms. This can be done bearing in mind the concept that human nature is not dualistic, but pluralistic. A system of ethical principles that includes the principles of good intentions, the correspondence of goals and means, the balancing of risks and benefits, simplicity, and contextuality, will help ensure that technologies are more humanistic and friendly to human beings.

  19. Dual-wavelength hybrid optoacoustic-ultrasound biomicroscopy for functional imaging of large-scale cerebral vascular networks.

    PubMed

    Rebling, Johannes; Estrada, Héctor; Gottschalk, Sven; Sela, Gali; Zwack, Michael; Wissmeyer, Georg; Ntziachristos, Vasilis; Razansky, Daniel

    2018-04-19

    A critical link exists between pathological changes of cerebral vasculature and diseases affecting brain function. Microscopic techniques have played an indispensable role in the study of neurovascular anatomy and functions. Yet, investigations are often hindered by suboptimal trade-offs between the spatiotemporal resolution, field-of-view (FOV) and type of contrast offered by the existing optical microscopy techniques. We present a hybrid dual-wavelength optoacoustic (OA) biomicroscope capable of rapid transcranial visualization of large-scale cerebral vascular networks. The system offers 3-dimensional views of the morphology and oxygenation status of the cerebral vasculature with single capillary resolution and a FOV exceeding 6 × 8 mm 2 , thus covering the entire cortical vasculature in mice. The large-scale OA imaging capacity is complemented by simultaneously acquired pulse-echo ultrasound (US) biomicroscopy scans of the mouse skull. The new approach holds great potential to provide better insights into cerebrovascular function and facilitate efficient studies into neurological and vascular abnormalities of the brain. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. A Case Study of Dual Language Program Administrators: The Teachers We Need

    ERIC Educational Resources Information Center

    Lachance, Joan R.

    2017-01-01

    In support of growing numbers of dual language programs nation-wide, dual language school administrators seek to find teachers who are specifically prepared to work with dual language learners for additive biliteracy. For this research the author utilized a case study design to explore practicing dual language administrators' perspectives…

  1. Dual-mode capability for hardware-in-the-loop

    NASA Astrophysics Data System (ADS)

    Vamivakas, A. N.; Jackson, Ron L.

    2000-07-01

    This paper details a Hardware-in-the-Loop Facility (HIL) developed for evaluation and verification of a missile system with dual mode capability. The missile has the capability of tracking and intercepting a target using either an RF antenna or an IR sensor. The testing of a dual mode system presents a significant challenge in the development of the HIL facility. An IR and RF target environment must be presented simultaneously to the missile under test. These targets, simulated by IR and RF sources, must be presented to the missile under test without interference from each other. The location of each source is critical in the development of the HIL facility. The requirements for building a HIL facility with dual mode capability and the methodology for testing the dual mode system are defined within this paper. Methods for the verification and validation of the facility are discussed.

  2. A Superconducting Dual-Channel Photonic Switch.

    PubMed

    Srivastava, Yogesh Kumar; Manjappa, Manukumara; Cong, Longqing; Krishnamoorthy, Harish N S; Savinov, Vassili; Pitchappa, Prakash; Singh, Ranjan

    2018-06-05

    The mechanism of Cooper pair formation and its underlying physics has long occupied the investigation into high temperature (high-T c ) cuprate superconductors. One of the ways to unravel this is to observe the ultrafast response present in the charge carrier dynamics of a photoexcited specimen. This results in an interesting approach to exploit the dissipation-less dynamic features of superconductors to be utilized for designing high-performance active subwavelength photonic devices with extremely low-loss operation. Here, dual-channel, ultrafast, all-optical switching and modulation between the resistive and the superconducting quantum mechanical phase is experimentally demonstrated. The ultrafast phase switching is demonstrated via modulation of sharp Fano resonance of a high-T c yttrium barium copper oxide (YBCO) superconducting metamaterial device. Upon photoexcitation by femtosecond light pulses, the ultrasensitive cuprate superconductor undergoes dual dissociation-relaxation dynamics, with restoration of superconductivity within a cycle, and thereby establishes the existence of dual switching windows within a timescale of 80 ps. Pathways are explored to engineer the secondary dissociation channel which provides unprecedented control over the switching speed. Most importantly, the results envision new ways to accomplish low-loss, ultrafast, and ultrasensitive dual-channel switching applications that are inaccessible through conventional metallic and dielectric based metamaterials. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Effect of dual-type oligosaccharides on constipation in loperamide-treated rats

    PubMed Central

    Han, Sung Hee; Hong, Ki Bae; Kim, Eun Young; Ahn, So Hyun

    2016-01-01

    BACKGROUND/OBJECTIVES Constipation is a condition that can result from intestinal deformation. Because humans have an upright posture, the effects of gravity can cause this shape deformation. Oligosaccharides are common prebiotics and their effects on bowel health are well known. However, studies of the physiological functionality of a product that contains both lactulose and galactooligosaccharides are insufficient. We investigated the constipation reduction effect of a dual-type oligosaccharide, Dual-Oligo, in loperamide-treated rats. MATERIALS/METHODS Dual-Oligo consists of galactooligosaccharides (15.80%) and lactulose (51.67%). Animals were randomly divided into four groups, the normal group (normal), control group (control), low concentration of Dual-Oligo (LDO) group, and high concentration of Dual-Oligo (HDO) group. After 7 days of oral administration, fecal pellet amount, fecal weight, water content of fecal were measured. Blood chemistry, short-chain fatty acid (SCFA), gastrointestinal transit ratio and length and intestinal mucosa were analyzed. RESULTS Dual-Oligo increased the fecal weight, and water content of feces in rats with loperamide-induced constipation. Gastrointestinal transit ratio and length and area of intestinal mucosa significantly increased after treatment with Dual-Oligo in loperamide-induced rats. A high concentration of Dual-Oligo tended to produce more acetic acid than that observed for the control group, and Dual-Oligo affected the production of total SCFA. Bifidobacteria concentration of cecal contents in the high-concentration oligosaccharide (HDO) and low-concentration oligosaccharide (LDO) groups was similar to the result of the normal group. CONCLUSIONS These results showed that Dual-Oligo is a functional material that is derived from a natural food product and is effective in ameliorating constipation. PMID:27909555

  4. Problems of Dual-Career Black Couples: Identification and Implications for Family Interventions.

    ERIC Educational Resources Information Center

    Thomas, Veronica G.

    1990-01-01

    Examined problems of 41 dual-career Black couples. Findings indicated that dual-career Black couples experienced a number of problems related to their lifestyle. Found unique problems perceived by dual-career Black families. In addition to problems experienced by White dual-career couples, Blacks also faced racial discrimination, social isolation,…

  5. Dual Low-Rank Pursuit: Learning Salient Features for Saliency Detection.

    PubMed

    Lang, Congyan; Feng, Jiashi; Feng, Songhe; Wang, Jingdong; Yan, Shuicheng

    2016-06-01

    Saliency detection is an important procedure for machines to understand visual world as humans do. In this paper, we consider a specific saliency detection problem of predicting human eye fixations when they freely view natural images, and propose a novel dual low-rank pursuit (DLRP) method. DLRP learns saliency-aware feature transformations by utilizing available supervision information and constructs discriminative bases for effectively detecting human fixation points under the popular low-rank and sparsity-pursuit framework. Benefiting from the embedded high-level information in the supervised learning process, DLRP is able to predict fixations accurately without performing the expensive object segmentation as in the previous works. Comprehensive experiments clearly show the superiority of the proposed DLRP method over the established state-of-the-art methods. We also empirically demonstrate that DLRP provides stronger generalization performance across different data sets and inherits the advantages of both the bottom-up- and top-down-based saliency detection methods.

  6. Improved dual-loop detection system for collecting real-time truck data

    DOT National Transportation Integrated Search

    2005-02-01

    The WSDOTs dual-loop detectors capability of measuring vehicle lengths makes the dual-loop detection system a potential real-time truck data source for freight movement study. However, a previous study found the WSDOT dual-loop detection system...

  7. Dual-Fuel Propulsion in Single-Stage Advanced Manned Launch System Vehicle

    NASA Technical Reports Server (NTRS)

    Lepsch, Roger A., Jr.; Stanley, Douglas O.; Unal, Resit

    1995-01-01

    As part of the United States Advanced Manned Launch System study to determine a follow-on, or complement, to the Space Shuttle, a reusable single-stage-to-orbit concept utilizing dual-fuel rocket propulsion has been examined. Several dual-fuel propulsion concepts were investigated. These include: a separate-engine concept combining Russian RD-170 kerosene-fueled engines with space shuttle main engine-derivative engines: the kerosene- and hydrogen-fueled Russian RD-701 engine; and a dual-fuel, dual-expander engine. Analysis to determine vehicle weight and size characteristics was performed using conceptual-level design techniques. A response-surface methodology for multidisciplinary design was utilized to optimize the dual-fuel vehicles with respect to several important propulsion-system and vehicle design parameters, in order to achieve minimum empty weight. The tools and methods employed in the analysis process are also summarized. In comparison with a reference hydrogen- fueled single-stage vehicle, results showed that the dual-fuel vehicles were from 10 to 30% lower in empty weight for the same payload capability, with the dual-expander engine types showing the greatest potential.

  8. Dual Enrollment: The Missing Link to College Readiness

    ERIC Educational Resources Information Center

    Swanson, Joni

    2010-01-01

    Dual enrollment programs have sparked the interest of educational researchers and practitioners who want to determine whether offering college courses to high school students might positively affect their persistence in college or other postsecondary education. Current research suggests that participating in dual enrollment programs improves…

  9. Dual pricing of health sciences periodicals: a survey.

    PubMed Central

    Miller, D R; Jensen, J E

    1980-01-01

    A survey of dual pricing practices among publishers of health-related journals identified 281 periodicals with an average price differential of over 100% between individual and institutional subscription rates. Both the practice itself and the amount of the differential are increasing, indicating that journal subscriptions of health sciences libraries increasingly provide the financial support necessary for the publication of health sciences journals. Dual pricing is also correlated with copyright royalties. The problems that dual pricing creates for health sciences libraries' budgets are due in part to uncritical purchasing by libraries. Increased consumerism on the part of health science librarians is recommended. PMID:7437588

  10. Holographic duals of 3d S-fold CFTs

    NASA Astrophysics Data System (ADS)

    Assel, Benjamin; Tomasiello, Alessandro

    2018-06-01

    We construct non-geometric AdS4 solutions of IIB string theory where the fields in overlapping patches are glued by elements of the S-duality group. We obtain them by suitable quotients of compact and non-compact geometric solutions. The quotient procedure suggests CFT duals as quiver theories with links involving the so-called T [U( N)] theory. We test the validity of the non-geometric solutions (and of our proposed holographic duality) by computing the three-sphere partition function Z of the CFTs. A first class of solutions is obtained by an S-duality quotient of Janus-type non-compact solutions and is dual to 3d N=4 SCFTs; for these we manage to compute Z of the dual CFT at finite N, and it agrees perfectly with the supergravity result in the large N limit. A second class has five-branes, it is obtained by a Möbius-like S-quotient of ordinary compact solutions and is dual to 3d N=3 SCFTs. For these, Z agrees with the supergravity result if one chooses the limit carefully so that the effect of the fivebranes does not backreact on the entire geometry. Other limits suggest the existence of IIA duals.

  11. Single-scan dual-tracer FLT+FDG PET tumor characterization.

    PubMed

    Kadrmas, Dan J; Rust, Thomas C; Hoffman, John M

    2013-02-07

    Rapid multi-tracer PET aims to image two or more tracers in a single scan, simultaneously characterizing multiple aspects of physiology and function without the need for repeat imaging visits. Using dynamic imaging with staggered injections, constraints on the kinetic behavior of each tracer are applied to recover individual-tracer measures from the multi-tracer PET signal. The ability to rapidly and reliably image both (18)F-fluorodeoxyglucose (FDG) and (18)F-fluorothymidine (FLT) would provide complementary measures of tumor metabolism and proliferative activity, with important applications in guiding oncologic treatment decisions and assessing response. However, this tracer combination presents one of the most challenging dual-tracer signal-separation problems--both tracers have the same radioactive half-life, and the injection delay is short relative to the half-life and tracer kinetics. This work investigates techniques for single-scan dual-tracer FLT+FDG PET tumor imaging, characterizing the performance of recovering static and dynamic imaging measures for each tracer from dual-tracer datasets. Simulation studies were performed to characterize dual-tracer signal-separation performance for imaging protocols with both injection orders and injection delays of 10-60 min. Better performance was observed when FLT was administered first, and longer delays before administration of FDG provided more robust signal-separation and recovery of the single-tracer imaging measures. An injection delay of 30 min led to good recovery (R > 0.96) of static image values (e.g. SUV), K(net), and K(1) as compared to values from separate, single-tracer time-activity curves. Recovery of higher order rate parameters (k(2), k(3)) was less robust, indicating that information regarding these parameters was harder to recover in the presence of statistical noise and dual-tracer effects. Performance of the dual-tracer FLT(0 min)+FDG(32 min) technique was further evaluated using PET/CT imaging

  12. Single-scan dual-tracer FLT+FDG PET tumor characterization

    NASA Astrophysics Data System (ADS)

    Kadrmas, Dan J.; Rust, Thomas C.; Hoffman, John M.

    2013-02-01

    Rapid multi-tracer PET aims to image two or more tracers in a single scan, simultaneously characterizing multiple aspects of physiology and function without the need for repeat imaging visits. Using dynamic imaging with staggered injections, constraints on the kinetic behavior of each tracer are applied to recover individual-tracer measures from the multi-tracer PET signal. The ability to rapidly and reliably image both 18F-fluorodeoxyglucose (FDG) and 18F-fluorothymidine (FLT) would provide complementary measures of tumor metabolism and proliferative activity, with important applications in guiding oncologic treatment decisions and assessing response. However, this tracer combination presents one of the most challenging dual-tracer signal-separation problems—both tracers have the same radioactive half-life, and the injection delay is short relative to the half-life and tracer kinetics. This work investigates techniques for single-scan dual-tracer FLT+FDG PET tumor imaging, characterizing the performance of recovering static and dynamic imaging measures for each tracer from dual-tracer datasets. Simulation studies were performed to characterize dual-tracer signal-separation performance for imaging protocols with both injection orders and injection delays of 10-60 min. Better performance was observed when FLT was administered first, and longer delays before administration of FDG provided more robust signal-separation and recovery of the single-tracer imaging measures. An injection delay of 30 min led to good recovery (R > 0.96) of static image values (e.g. SUV), Knet, and K1 as compared to values from separate, single-tracer time-activity curves. Recovery of higher order rate parameters (k2, k3) was less robust, indicating that information regarding these parameters was harder to recover in the presence of statistical noise and dual-tracer effects. Performance of the dual-tracer FLT(0 min)+FDG(32 min) technique was further evaluated using PET/CT imaging studies in

  13. Single-scan dual-tracer FLT+FDG PET tumor characterization

    PubMed Central

    Kadrmas, Dan J; Rust, Thomas C; Hoffman, John M

    2013-01-01

    Rapid multi-tracer PET aims to image two or more tracers in a single scan, simultaneously characterizing multiple aspects of physiology and function without the need for repeat imaging visits. Using dynamic imaging with staggered injections, constraints on the kinetic behavior of each tracer are applied to recover individual-tracer measures from the multi-tracer PET signal. The ability to rapidly and reliably image both 18F-fluorodeoxyglucose (FDG) and 18F-fluorothymidine (FLT) would provide complementary measures of tumor metabolism and proliferative activity, with important applications in guiding oncologic treatment decisions and assessing response. However, this tracer combination presents one of the most challenging dual-tracer signal-separation problems—both tracers have the same radioactive half-life, and the injection delay is short relative to the half-life and tracer kinetics. This work investigates techniques for single-scan dual-tracer FLT+FDG PET tumor imaging, characterizing the performance of recovering static and dynamic imaging measures for each tracer from dual-tracer datasets. Simulation studies were performed to characterize dual-tracer signal-separation performance for imaging protocols with both injection orders and injection delays of 10–60 min. Better performance was observed when FLT was administered first, and longer delays before administration of FDG provided more robust signal-separation and recovery of the single-tracer imaging measures. An injection delay of 30 min led to good recovery (R > 0.96) of static image values (e.g. SUV), Knet, and K1 as compared to values from separate, single-tracer time-activity curves. Recovery of higher order rate parameters (k2, k3) was less robust, indicating that information regarding these parameters was harder to recover in the presence of statistical noise and dual-tracer effects. Performance of the dual-tracer FLT(0 min)+FDG(32 min) technique was further evaluated using PET/CT imaging studies

  14. The Wellbeing of Army Personnel in Dual Military Marriages

    DTIC Science & Technology

    2015-11-01

    my pregnant wife, you know, she didn’t have anybody. It was her first kid , our first kid , and nobody paid me to have to watch my son being born over...set and further examined the role that sex has in dual-military marriages, with a focus on career intentions. I predicted that not only is gender...collected thus far: Table 4. Demographic data Married: Dual-Military Married: Not Dual Military N 276 673 Sex Male: 52% Female: 48

  15. Dual-frequency continuous wave optical parametric oscillator

    NASA Astrophysics Data System (ADS)

    Sun, Bingjie; Wang, Xin; Yang, Suhui; Li, Kun

    2018-01-01

    This article shows a dual-frequency OPO with multi-grating (28.5-31.5 μm) periodically poled MgO:LiNbO3 (MgO:PPLN) pumped by a dual-frequency continuous wave at 1.064 μm. The wavelengths of idler and signal varying versus temperature at different periods of inverted domains were numerical simulated. It proves that as the temperature rises, or as the poling period increases, the idler wavelength shortens and signal wavelength lengthens. The pump is a 30 W dual-frequency fiber laser MOPA with beat note frequency varying from 125 MHz to 175 MHz. The pump threshold of the bow-tie ring cavity OPO was 3 W. An average dual-frequency idler output power of 2.6 W was obtained when the pump power was 17.2 W at 45 °C. The idler wavelength was 3.4 μm when the poling period was 30.5 μm. The idler wavelength could be tuned from 2.9 μm to 3.9 μm by changing the temperature and the poling period, and the beat note frequency was proved to be equal to that of the pump.

  16. Dual Enrollment Programs. What Works Clearinghouse Intervention Report

    ERIC Educational Resources Information Center

    What Works Clearinghouse, 2017

    2017-01-01

    "Dual enrollment" programs allow high school students to take college courses and earn college credits while still attending high school. Such programs, also referred to as "dual credit" or early college programs, are designed to boost college access and degree attainment, especially for students typically underrepresented in…

  17. Euclidean supersymmetric solutions with the self-dual Weyl tensor

    NASA Astrophysics Data System (ADS)

    Nozawa, Masato

    2017-07-01

    We explore the Euclidean supersymmetric solutions admitting the self-dual gauge field in the framework of N = 2 minimal gauged supergravity in four dimensions. According to the classification scheme utilizing the spinorial geometry or the bilinears of Killing spinors, the general solution preserves one quarter of supersymmetry and is described by the Przanowski-Tod class with the self-dual Weyl tensor. We demonstrate that there exists an additional Killing spinor, provided the Przanowski-Tod metric admits a Killing vector that commutes with the principal one. The proof proceeds by recasting the metric into another Przanowski-Tod form. This formalism enables us to show that the self-dual Reissner-Nordström-Taub-NUT-AdS metric possesses a second Killing spinor, which has been missed over many years. We also address the supersymmetry when the Przanowski-Tod space is conformal to each of the self-dual ambi-toric Kähler metrics. It turns out that three classes of solutions are all reduced to the self-dual Carter family, by virtue of the nondegenerate Killing-Yano tensor.

  18. Assessing stakeholder perceptions of the acceptability and feasibility of national scale-up for a dual HIV/syphilis rapid diagnostic test in Malawi.

    PubMed

    Maddox, Brandy L Peterson; Wright, Shauntā S; Namadingo, Hazel; Bowen, Virginia B; Chipungu, Geoffrey A; Kamb, Mary L

    2017-12-01

    The WHO recommends pregnant women receive both HIV and syphilis testing at their first antenatal care visit, as untreated maternal infections can lead to severe, adverse pregnancy outcomes. One strategy for increasing testing for both HIV and syphilis is the use of point-of-care (rapid) diagnostic tests that are simple, proven effective and inexpensive. In Malawi, pregnant women routinely receive HIV testing, but only 10% are tested for syphilis at their first antenatal care visit. This evaluation explores stakeholder perceptions of a novel, dual HIV/syphilis rapid diagnostic test and potential barriers to national scale-up of the dual test in Malawi. During June and July 2015, we conducted 15 semistructured interviews with 25 healthcare workers, laboratorians, Ministry of Health leaders and partner agency representatives working in prevention of mother-to-child transmission in Malawi. We asked stakeholders about the importance of a dual rapid diagnostic test, concerns using and procuring the dual test and recommendations for national expansion. Stakeholders viewed the test favourably, citing the importance of a dual rapid test in preventing missed opportunities for syphilis diagnosis and treatment, improving infant outcomes and increasing syphilis testing coverage. Primary technical concerns were about the additional procedural steps needed to perform the test, the possibility that testers may not adhere to required waiting times before interpreting results and difficulty reading and interpreting test results. Stakeholders thought national scale-up would require demonstration of cost-savings, uniform coordination, revisions to testing guidelines and algorithms, training of testers and a reliable supply chain. Stakeholders largely support implementation of a dual HIV/syphilis rapid diagnostic test as a feasible alternative to current antenatal testing. Scale-up will require addressing perceived barriers; negotiating changes to existing algorithms and guidelines

  19. Adaptive real-time dual-comb spectroscopy.

    PubMed

    Ideguchi, Takuro; Poisson, Antonin; Guelachvili, Guy; Picqué, Nathalie; Hänsch, Theodor W

    2014-02-27

    The spectrum of a laser frequency comb consists of several hundred thousand equally spaced lines over a broad spectral bandwidth. Such frequency combs have revolutionized optical frequency metrology and they now hold much promise for significant advances in a growing number of applications including molecular spectroscopy. Despite an intriguing potential for the measurement of molecular spectra spanning tens of nanometres within tens of microseconds at Doppler-limited resolution, the development of dual-comb spectroscopy is hindered by the demanding stability requirements of the laser combs. Here we overcome this difficulty and experimentally demonstrate a concept of real-time dual-comb spectroscopy, which compensates for laser instabilities by electronic signal processing. It only uses free-running mode-locked lasers without any phase-lock electronics. We record spectra spanning the full bandwidth of near-infrared fibre lasers with Doppler-limited line profiles highly suitable for measurements of concentrations or line intensities. Our new technique of adaptive dual-comb spectroscopy offers a powerful transdisciplinary instrument for analytical sciences.

  20. Adaptive real-time dual-comb spectroscopy

    NASA Astrophysics Data System (ADS)

    Ideguchi, Takuro; Poisson, Antonin; Guelachvili, Guy; Picqué, Nathalie; Hänsch, Theodor W.

    2014-02-01

    The spectrum of a laser frequency comb consists of several hundred thousand equally spaced lines over a broad spectral bandwidth. Such frequency combs have revolutionized optical frequency metrology and they now hold much promise for significant advances in a growing number of applications including molecular spectroscopy. Despite an intriguing potential for the measurement of molecular spectra spanning tens of nanometres within tens of microseconds at Doppler-limited resolution, the development of dual-comb spectroscopy is hindered by the demanding stability requirements of the laser combs. Here we overcome this difficulty and experimentally demonstrate a concept of real-time dual-comb spectroscopy, which compensates for laser instabilities by electronic signal processing. It only uses free-running mode-locked lasers without any phase-lock electronics. We record spectra spanning the full bandwidth of near-infrared fibre lasers with Doppler-limited line profiles highly suitable for measurements of concentrations or line intensities. Our new technique of adaptive dual-comb spectroscopy offers a powerful transdisciplinary instrument for analytical sciences.

  1. Adaptive real-time dual-comb spectroscopy

    PubMed Central

    Ideguchi, Takuro; Poisson, Antonin; Guelachvili, Guy; Picqué, Nathalie; Hänsch, Theodor W.

    2014-01-01

    The spectrum of a laser frequency comb consists of several hundred thousand equally spaced lines over a broad spectral bandwidth. Such frequency combs have revolutionized optical frequency metrology and they now hold much promise for significant advances in a growing number of applications including molecular spectroscopy. Despite an intriguing potential for the measurement of molecular spectra spanning tens of nanometres within tens of microseconds at Doppler-limited resolution, the development of dual-comb spectroscopy is hindered by the demanding stability requirements of the laser combs. Here we overcome this difficulty and experimentally demonstrate a concept of real-time dual-comb spectroscopy, which compensates for laser instabilities by electronic signal processing. It only uses free-running mode-locked lasers without any phase-lock electronics. We record spectra spanning the full bandwidth of near-infrared fibre lasers with Doppler-limited line profiles highly suitable for measurements of concentrations or line intensities. Our new technique of adaptive dual-comb spectroscopy offers a powerful transdisciplinary instrument for analytical sciences. PMID:24572636

  2. Dual antibiotics for bronchiectasis.

    PubMed

    Felix, Lambert M; Grundy, Seamus; Milan, Stephen J; Armstrong, Ross; Harrison, Haley; Lynes, Dave; Spencer, Sally

    2018-06-11

    Bronchiectasis is a chronic respiratory disease characterised by abnormal and irreversible dilatation of the smaller airways and associated with a mortality rate greater than twice that of the general population. Antibiotics serve as front-line therapy for managing bacterial load, but their use is weighed against the development of antibiotic resistance. Dual antibiotic therapy has the potential to suppress infection from multiple strains of bacteria, leading to more successful treatment of exacerbations, reduced symptoms, and improved quality of life. Further evidence is required on the efficacy of dual antibiotics in terms of management of exacerbations and extent of antibiotic resistance. To evaluate the effects of dual antibiotics in the treatment of adults and children with bronchiectasis. We identified studies from the Cochrane Airways Group Specialised Register (CAGR), which includes the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, the Cumulative Index to Nursing and Allied Health Literature (CINAHL), Allied and Complementary Medicine (AMED), and PsycINFO, as well as studies obtained by handsearching of journals/abstracts. We also searched the following trial registries: US National Institutes of Health Ongoing Trials Register, ClinicalTrials.gov, and the World Health Organization (WHO) International Clinical Trials Registry Platform. We imposed no restriction on language of publication. We conducted our search in October 2017. We searched for randomised controlled trials comparing dual antibiotics versus a single antibiotic for short-term (< 4 weeks) or long-term management of bronchiectasis diagnosed in adults and/or children by bronchography, plain film chest radiography, or high-resolution computed tomography. Primary outcomes included exacerbations, length of hospitalisation, and serious adverse events. Secondary outcomes were response rates, emergence of resistance to antibiotics, systemic markers of infection, sputum

  3. Dual-energy contrast-enhanced mammography.

    PubMed

    Travieso Aja, M M; Rodríguez Rodríguez, M; Alayón Hernández, S; Vega Benítez, V; Luzardo, O P

    2014-01-01

    The degree of vascularization in breast lesions is related to their malignancy. For this reason, functional diagnostic imaging techniques have become important in recent years. Dual-energy contrast-enhanced mammography is a new, apparently promising technique in breast cancer that provides information about the degree of vascularization of the lesion in addition to the morphological information provided by conventional mammography. This article describes the state of the art for dual-energy contrast-enhanced mammography. Based on 15 months' clinical experience, we illustrate this review with clinical cases that allow us to discuss the advantages and limitations of this technique. Copyright © 2014 SERAM. Published by Elsevier Espana. All rights reserved.

  4. Comparison of dual-biomarker PIB-PET and dual-tracer PET in AD diagnosis.

    PubMed

    Fu, Liping; Liu, Linwen; Zhang, Jinming; Xu, Baixuan; Fan, Yong; Tian, Jiahe

    2014-11-01

    To identify the optimal time window for capturing perfusion information from early (11)C-PIB imaging frames (perfusion PIB, (11)C-pPIB) and to compare the performance of (18)F-FDG PET and "dual biomarker" (11)C-PIB PET [(11)C-pPIB and amyloid PIB ((11)C-aPIB)] for classification of AD, MCI and CN subjects. Forty subjects (14 CN, 12 MCI and 14 AD patients) underwent (18)F-FDG and (11)C-PIB PET studies. Pearson correlation between the (18)F-FDG image and sum of early (11)C-PIB frames was maximised to identify the optimal time window for (11)C-pPIB. The classification power of imaging parameters was evaluated with a leave-one-out validation. A 7-min time window yielded the highest correlation between (18)F-FDG and (11)C-pPIB. (11)C-pPIB and (18)F-FDG images shared a similar radioactive distribution pattern. (18)F-FDG performed better than (11)C-pPIB for the classification of both AD vs. CN and MCI vs. CN. (11)C-pPIB + (11)C-aPIB and (18)F-FDG + (11)C-aPIB yielded the highest classification accuracy for the classification of AD vs. CN, and (18)F-FDG + (11)C-aPIB had the best classification performance for the classification of MCI vs. C-pPIB could serve as a useful biomarker of rCBF for measuring neural activity and improve the diagnostic power of PET for AD in conjunction with (11)C-aPIB. (18)F-FDG and (11)C-PIB dual-tracer PET examination could better detect MCI. • Dual-tracer PET examination provides neurofunctional and neuropathological information for AD diagnosis. • The identified optimal 11C-pPIB time frames had highest correlation with 18F-FDG. • 11C-pPIB images shared a similar radioactive distribution pattern with 18F-FDG images. • 11C-pPIB can provide neurofunctional information. • Dual-tracer PET examination could better detect MCI.

  5. Improved dual-porosity models for petrophysical analysis of vuggy reservoirs

    NASA Astrophysics Data System (ADS)

    Wang, Haitao

    2017-08-01

    A new vug interconnection, isolated vug (IVG), was investigated through resistivity modeling and the dual-porosity model for connected vug (CVG) vuggy reservoirs was tested. The vuggy models were built by pore-scale modeling, and their electrical resistivity was calculated by the finite difference method. For CVG vuggy reservoirs, the CVG reduced formation factors and increased the porosity exponents, and the existing dual-porosity model failed to match these results. Based on the existing dual-porosity model, a conceptual dual-porosity model for CVG was developed by introducing a decoupled term to reduce the resistivity of the model. For IVG vuggy reservoirs, IVG increased the formation factors and porosity exponents. The existing dual-porosity model succeeded due to accurate calculation of the formation factors of the deformed interparticle porous media caused by the insertion of the IVG. Based on the existing dual-porosity model, a new porosity model for IVG vuggy reservoirs was developed by simultaneously recalculating the formation factors of the altered interparticle pore-scale models. The formation factors and porosity exponents from the improved and extended dual-porosity models for CVG and IVG vuggy reservoirs well matched the simulated formation factors and porosity exponents. This work is helpful for understanding the influence of connected and disconnected vugs on resistivity factors—an issue of particular importance in carbonates.

  6. Pueblo Community College, Dual Credit Handbook, 1998-99.

    ERIC Educational Resources Information Center

    Griffith, Mary

    This Dual Credit Handbook from Pueblo Community College (CO) provides information and guidelines to assist instructors in meeting their assignment. These guidelines apply to dual credit courses offered to high school students during their regular school hours, for which students receive high school- and college-level credit simultaneously. This…

  7. A Survey of Dual Career Couples in Engineering.

    ERIC Educational Resources Information Center

    Haemmerlie, Frances M.; Montgomery, Robert L.

    Interest in the problems and concerns of dual career couples has increased markedly in the last decade. However, little research has been done with dual career couples in such traditionally non-female professions as engineering. To examine work, home, personal, and interpersonal characteristics and concerns, married female engineering graduates…

  8. Multi-wavelength dual polarisation lidar for monitoring precipitation process in the cloud seeding technique

    NASA Astrophysics Data System (ADS)

    Sudhakar, P.; Sheela, K. Anitha; Ramakrishna Rao, D.; Malladi, Satyanarayana

    2016-05-01

    In recent years weather modification activities are being pursued in many countries through cloud seeding techniques to facilitate the increased and timely precipitation from the clouds. In order to induce and accelerate the precipitation process clouds are artificially seeded with suitable materials like silver iodide, sodium chloride or other hygroscopic materials. The success of cloud seeding can be predicted with confidence if the precipitation process involving aerosol, the ice water balance, water vapor content and size of the seeding material in relation to aerosol in the cloud is monitored in real time and optimized. A project on the enhancement of rain fall through cloud seeding is being implemented jointly with Kerala State Electricity Board Ltd. Trivandrum, Kerala, India at the catchment areas of the reservoir of one of the Hydro electric projects. The dual polarization lidar is being used to monitor and measure the microphysical properties, the extinction coefficient, size distribution and related parameters of the clouds. The lidar makes use of the Mie, Rayleigh and Raman scattering techniques for the various measurement proposed. The measurements with the dual polarization lidar as above are being carried out in real time to obtain the various parameters during cloud seeding operations. In this paper we present the details of the multi-wavelength dual polarization lidar being used and the methodology to monitor the various cloud parameters involved in the precipitation process. The necessary retrieval algorithms for deriving the microphysical properties of clouds, aerosols characteristics and water vapor profiles are incorporated as a software package working under Lab-view for online and off line analysis. Details on the simulation studies and the theoretical model developed in this regard for the optimization of various parameters are discussed.

  9. Picometer-resolution dual-comb spectroscopy with a free-running fiber laser.

    PubMed

    Zhao, Xin; Hu, Guoqing; Zhao, Bofeng; Li, Cui; Pan, Yingling; Liu, Ya; Yasui, Takeshi; Zheng, Zheng

    2016-09-19

    Dual-comb spectroscopy holds the promise as real-time, high-resolution spectroscopy tools. However, in its conventional schemes, the stringent requirement on the coherence between two lasers requires sophisticated control systems. By replacing control electronics with an all-optical dual-comb lasing scheme, a simplified dual-comb spectroscopy scheme is demonstrated using one dual-wavelength, passively mode-locked fiber laser. Pulses with a intracavity-dispersion-determined repetition-frequency difference are shown to have good mutual coherence and stability. Capability to resolve the comb teeth and a picometer-wide optical spectral resolution are demonstrated using a simple data acquisition system. Energy-efficient, free-running fiber lasers with a small comb-tooth-spacing could enable low-cost dual-comb systems.

  10. Adverse Effects in Dual-Star Interferometry

    NASA Technical Reports Server (NTRS)

    Colavita, M. Mark

    2008-01-01

    Narrow-angle dual-star interferometric astrometry can provide very high accuracy in the presence of the Earth's turbulent atmosphere. However, to exploit the high atmospherically-limited accuracy requires control of systematic errors in measurement of the interferometer baseline, internal OPDs, and fringe phase. In addition, as high photometric SNR is required, care must be taken to maximize throughput and coherence to obtain high accuracy on faint stars. This article reviews: the keys aspects of the dual-star approach and implementation; the main contributors to the

  11. Gray matter volume and dual-task gait performance in mild cognitive impairment

    PubMed Central

    Blumen, Helena M.; Verghese, Joe; Shimada, Hiroyuki; Makizako, Hyuma; Tsutsumimoto, Kota; Hotta, Ryo; Nakakubo, Sho; Suzuki, Takao

    2017-01-01

    Dual-task gait performance is impaired in older adults with mild cognitive impairment, but the brain substrates associated with dual-task gait performance are not well-established. The relationship between gray matter and gait speed under single-task and dual-task conditions (walking while counting backward) was examined in 560 seniors with mild cognitive impairment (non-amnestic mild cognitive impairment: n = 270; mean age = 72.4 yrs., 63.6 % women; amnestic mild cognitive impairment: n = 290; mean age = 73.4 yrs., 45.4 % women). Multivariate covariance-based analyses of magnetic resonance imaging data, adjusted for potential confounders including single-task gait speed, were performed to identify gray matter patterns associated with dual-task gait speed. There were no differences in gait speed or cognitive performance during dual-task gait between individuals with non-amnestic mild cognitive impairment and amnestic mild cognitive impairment. Overall, increased dual-task gait speed was associated with a gray matter pattern of increased volume in medial frontal gyrus, superior frontal gyrus, anterior cingulate, cingulate, precuneus, fusiform gyrus, middle occipital gyrus, inferior temporal gyrus and middle temporal gyrus. The relationship between dual-task gait speed and brain substrates also differed by mild cognitive impairment subtype. Our study revealed a pattern of gray matter regions associated with dual-task performance. Although dual-task gait performance was similar in amnestic and non-amnestic mild cognitive impairment, the gray matter patterns associated with dual-task gait performance differed by mild cognitive impairment subtype. These findings suggest that the brain substrates supporting dual-task gait performance in amnestic and non-amnestic subtypes are different, and consequently may respond differently to interventions, or require different interventions. PMID:27392792

  12. Comparison of dual and single exposure techniques in dual-energy chest radiography.

    PubMed

    Ho, J T; Kruger, R A; Sorenson, J A

    1989-01-01

    Conventional chest radiography is the most effective tool for lung cancer detection and diagnosis; nevertheless, a high percentage of lung cancer tumors are missed because of the overlap of lung nodule image contrast with bone image contrast in a chest radiograph. Two different energy subtraction strategies, dual exposure and single exposure techniques, were studied for decomposing a radiograph into bone-free and soft tissue-free images to address this problem. For comparing the efficiency of these two techniques in lung nodule detection, the performances of the techniques were evaluated on the basis of residual tissue contrast, energy separation, and signal-to-noise ratio. The evaluation was based on both computer simulation and experimental verification. The dual exposure technique was found to be better than the single exposure technique because of its higher signal-to-noise ratio and greater residual tissue contrast. However, x-ray tube loading and patient motion are problems.

  13. Carcass and meat quality of dual-purpose chickens (Lohmann Dual, Belgian Malines, Schweizerhuhn) in comparison to broiler and layer chicken types.

    PubMed

    Mueller, S; Kreuzer, M; Siegrist, M; Mannale, K; Messikommer, R E; Gangnat, I D M

    2018-05-18

    Currently, there is an intensive ethical discussion about the practice of culling day-old layer cockerels. One solution to avoid this practice could be using dual-purpose types, where males are fattened for meat and females used for egg production. The aim of the present study was to compare fattening performance, carcass conformation, and composition as well as meat quality of Lohmann Dual, a novel dual-purpose type, and 2 traditional dual-purpose types (Belgian Malines and Schweizerhuhn) with 2 broiler types and 1 layer type (Lohmann Brown Plus). Broilers included a conventional line (Ross PM3) and a slower-growing line (Sasso 51) fulfilling requirements of organic farming. Nine birds of each type were fed on a conventional broiler diet. Feed intake and metabolizability of nitrogen and energy were recorded per pen (n = 3), the latter through excreta sampling. For each bird, carcass conformation was assessed, and weights of body, carcass, breast meat, legs, wings, and inner organs were determined. Additionally, breast angle, an indicator for carcass appeal, and skin color were recorded. Meat quality assessment included determinations of thaw and cooking loss, shear force, meat color, and proximate composition of the breast meat. None of the dual-purpose types (20 to 30 g ADG) performed as well in growth as the intensively growing broiler line (68 g ADG). However, Lohmann Dual could compete with the slower-growing broiler line (slower growth but better feed efficiency, similar in carcass weight and breast proportion). Also breast angle was quite similar between Lohmann Dual (100°) and the extensive broiler type (115°C) compared to the intensive broiler line (180°). Meat quality was most favorable in the intensive broilers with the smallest shear force and thawing loss, whereas meat quality was not different between the other types. The Schweizerhuhn performed only at the level of the layer hybrid, and the Belgian Malines was ranked only slightly better.

  14. A new approach for shaping of dual-reflector antennas

    NASA Technical Reports Server (NTRS)

    Lee, Teh-Hong; Burnside, W. D.; Rudduck, Roger C.

    1987-01-01

    The shaping of 2-D dual-reflector antenna systems to generate a prescribed distribution with uniform phase at the aperture of the second reflector is examined. This method is based on the geometrical nature of Cassegrain and Gregorian dual-reflector antennas. The method of syntheses satisfies the principles of geometrical optics which are the foundations of dual-reflector designs. Instead of setting up differential equations or heuristically designing the subreflector, a set of algebraic equations is formulated and solved numerically to obtain the desired surfaces. The caustics of the reflected rays from the subreflector can be obtained and examined. Several examples of 2-D dual-reflector shaping are shown to validate the study. Geometrical optics and physical optics are used to calculate the scattered fields from the reflectors.

  15. Dual-band polarization-/angle-insensitive metamaterial absorber

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Xiong, Han; Chongqing University, College of Communication Engineering, Chongqing, 400044; Zhong, Lin-Lin

    A dual-band metamaterial absorber (MA) based on triangular resonators is designed and investigated in this paper. It is composed of a two-dimensional periodic metal-dielectric-metal sandwiches array on a dielectric substrate. The simulation results clearly show that this absorber has two absorption peaks at 14.9 and 18.9 GHz, respectively, and experiments are conducted to verify the proposed designs effectively. For each polarization, the dual-band absorber is insensitive to the incident angle (up to 60°) and the absorption peaks remain high for both transverse electric (TE) and transverse magnetic (TM) radiation. To study the physical mechanism of power loss, the current distributionmore » at the dual absorption peaks is given. The MA proposed in this paper has potential applications in many scientific and martial fields.« less

  16. In vivo Study of the Accuracy of Dual-arch Impressions.

    PubMed

    de Lima, Luciana Martinelli Santayana; Borges, Gilberto Antonio; Junior, Luiz Henrique Burnett; Spohr, Ana Maria

    2014-06-01

    This study evaluated in vivo the accuracy of metal (Smart®) and plastic (Triple Tray®) dual-arch trays used with vinyl polysiloxane (Flexitime®), in the putty/wash viscosity, as well as polyether (Impregum Soft®) in the regular viscosity. In one patient, an implant-level transfer was screwed on an implant in the mandibular right first molar, serving as a pattern. Ten impressions were made with each tray and impression material. The impressions were poured with Type IV gypsum. The width and height of the pattern and casts were measured in a profile projector (Nikon). The results were submitted to Student's t-test for one sample (α = 0.05). For the width distance, the plastic dual-arch trays with vinyl polysiloxane (4.513 mm) and with polyether (4.531 mm) were statistically wider than the pattern (4.489 mm). The metal dual-arch tray with vinyl polysiloxane (4.504 mm) and with polyether (4.500 mm) did not differ statistically from the pattern. For the height distance, only the metal dual-arch tray with polyether (2.253 mm) differed statistically from the pattern (2.310 mm). The metal dual-arch tray with vinyl polysiloxane, in the putty/wash viscosities, reproduced casts with less distortion in comparison with the same technique with the plastic dual-arch tray. The plastic or metal dual-arch trays with polyether reproduced cast with greater distortion. How to cite the article: Santayana de Lima LM, Borges GA, Burnett LH Jr, Spohr AM. In vivo study of the accuracy of dual-arch impressions. J Int Oral Health 2014;6(3):50-5.

  17. Titanium nitride formation by a dual-stage femtosecond laser process

    NASA Astrophysics Data System (ADS)

    Hammouti, S.; Holybee, B.; Zhu, W.; Allain, J. P.; Jurczyk, B.; Ruzic, D. N.

    2018-06-01

    Formation of TiN by femtosecond laser processing in controlled gas atmosphere is reported. A dual-stage process was designed and aimed to first remove and restructure the native oxide layer of titanium surface through laser irradiation under an argon-controlled atmosphere, and then to maximize titanium nitride formation through an irradiation under a nitrogen reactive environment. An extensive XPS study was performed to identify and quantify laser-induced titanium surface chemistry modifications after a single-stage laser process (Ar and N2 individually), and a dual-stage laser process. The importance of each step that composes the dual-stage laser process was demonstrated and leads to the dual-stage laser process for the formation of TiO, Ti2O3 and TiN. In this study, the largest nitride formation occurs for the dual stage process with laser conditions at 4 W/1.3 J cm-2 under argon and 5 W/1.6 J cm-2 under nitrogen, yielding a total TiN composition of 8.9%. Characterization of both single-stage and dual-stage laser process-induced surface morphologies has been performed as well, leading to the observation of a wide range of hierarchical surface structures such as high-frequency ripples, grooves, protuberances and pillow-like patterns. Finally, water wettability was assessed by means of contact angle measurements on untreated titanium surface, and titanium surfaces resulting from either single-stage laser process or dual-stage laser process. Dual-stage laser process allows a transition of titanium surface, from phobic (93°) to philic (35°), making accessible both hydrophilic and chemically functionalized hierarchical surfaces.

  18. Dual delivery of biological therapeutics for multimodal and synergistic cancer therapies.

    PubMed

    Jang, Bora; Kwon, Hyokyoung; Katila, Pramila; Lee, Seung Jin; Lee, Hyukjin

    2016-03-01

    Cancer causes >8.2 million deaths annually worldwide; thus, various cancer treatments have been investigated over the past decades. Among them, combination drug therapy has become extremely popular, and treatment with more than one drug is often necessary to achieve appropriate anticancer efficacy. With the development of nanoformulations and nanoparticulate-based drug delivery, researchers have explored the feasibility of dual delivery of biological therapeutics to overcome the current drawbacks of cancer therapy. Compared with the conventional single drug therapy, dual delivery of therapeutics has provided various synergistic effects in addition to offering multimodality to cancer treatment. In this review, we highlight and summarize three aspects of dual-delivery systems for cancer therapy. These include (1) overcoming drug resistance by the dual delivery of chemical drugs with biological therapeutics for synergistic therapy, (2) targeted and controlled drug release by the dual delivery of drugs with stimuli-responsive nanomaterials, and (3) multimodal theranostics by the dual delivery of drugs and molecular imaging probes. Furthermore, recent developments, perspectives, and new challenges regarding dual-delivery systems for cancer therapy are discussed. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Attentional Control via Parallel Target-Templates in Dual-Target Search

    PubMed Central

    Barrett, Doug J. K.; Zobay, Oliver

    2014-01-01

    Simultaneous search for two targets has been shown to be slower and less accurate than independent searches for the same two targets. Recent research suggests this ‘dual-target cost’ may be attributable to a limit in the number of target-templates than can guide search at any one time. The current study investigated this possibility by comparing behavioural responses during single- and dual-target searches for targets defined by their orientation. The results revealed an increase in reaction times for dual- compared to single-target searches that was largely independent of the number of items in the display. Response accuracy also decreased on dual- compared to single-target searches: dual-target accuracy was higher than predicted by a model restricting search guidance to a single target-template and lower than predicted by a model simulating two independent single-target searches. These results are consistent with a parallel model of dual-target search in which attentional control is exerted by more than one target-template at a time. The requirement to maintain two target-templates simultaneously, however, appears to impose a reduction in the specificity of the memory representation that guides search for each target. PMID:24489793

  20. Dual-band plasmonic resonator based on Jerusalem cross-shaped nanoapertures

    NASA Astrophysics Data System (ADS)

    Cetin, Arif E.; Kaya, Sabri; Mertiri, Alket; Aslan, Ekin; Erramilli, Shyamsunder; Altug, Hatice; Turkmen, Mustafa

    2015-06-01

    In this paper, we both experimentally and numerically introduce a dual-resonant metamaterial based on subwavelength Jerusalem cross-shaped apertures. We numerically investigate the physical origin of the dual-resonant behavior, originating from the constituting aperture elements, through finite difference time domain calculations. Our numerical calculations show that at the dual-resonances, the aperture system supports large and easily accessible local electromagnetic fields. In order to experimentally realize the aperture system, we utilize a high-precision and lift-off free fabrication method based on electron-beam lithography. We also introduce a fine-tuning mechanism for controlling the dual-resonant spectral response through geometrical device parameters. Finally, we show the aperture system's highly advantageous far- and near-field characteristics through numerical calculations on refractive index sensitivity. The quantitative analyses on the availability of the local fields supported by the aperture system are employed to explain the grounds behind the sensitivity of each spectral feature within the dual-resonant behavior. Possessing dual-resonances with large and accessible electromagnetic fields, Jerusalem cross-shaped apertures can be highly advantageous for wide range of applications demanding multiple spectral features with strong nearfield characteristics.

  1. Self-dual Skyrmions on the spheres S2 N +1

    NASA Astrophysics Data System (ADS)

    Amari, Y.; Ferreira, L. A.

    2018-04-01

    We construct self-dual sectors for scalar field theories on a (2 N +2 )-dimensional Minkowski space-time with the target space being the 2 N +1 -dimensional sphere S2 N +1. The construction of such self-dual sectors is made possible by the introduction of an extra functional in the action that renders the static energy and the self-duality equations conformally invariant on the (2 N +1 )-dimensional spatial submanifold. The conformal and target-space symmetries are used to build an ansatz that leads to an infinite number of exact self-dual solutions with arbitrary values of the topological charge. The five-dimensional case is discussed in detail, where it is shown that two types of theories admit self-dual sectors. Our work generalizes the known results in the three-dimensional case that lead to an infinite set of self-dual Skyrmion solutions.

  2. Dual-Energy Computed Tomography in Cardiothoracic Vascular Imaging.

    PubMed

    De Santis, Domenico; Eid, Marwen; De Cecco, Carlo N; Jacobs, Brian E; Albrecht, Moritz H; Varga-Szemes, Akos; Tesche, Christian; Caruso, Damiano; Laghi, Andrea; Schoepf, Uwe Joseph

    2018-07-01

    Dual energy computed tomography is becoming increasingly widespread in clinical practice. It can expand on the traditional density-based data achievable with single energy computed tomography by adding novel applications to help reach a more accurate diagnosis. The implementation of this technology in cardiothoracic vascular imaging allows for improved image contrast, metal artifact reduction, generation of virtual unenhanced images, virtual calcium subtraction techniques, cardiac and pulmonary perfusion evaluation, and plaque characterization. The improved diagnostic performance afforded by dual energy computed tomography is not associated with an increased radiation dose. This review provides an overview of dual energy computed tomography cardiothoracic vascular applications. Copyright © 2018 Elsevier Inc. All rights reserved.

  3. Dual redundant arm system operational quality measures and their applications - Static measures

    NASA Technical Reports Server (NTRS)

    Lee, Sukhan; Kim, Sungbok

    1990-01-01

    The authors present dual-arm system static operational quality measures which quantify the efficiency and capability of a dual-arm system in generating Cartesian velocities and static forces. First, they define and analyze the kinematic interactions between the two arms incurred by the various modes of dual-arm cooperation, such as transport, assembly, and grasping modes of cooperation, and specify the kinematic constraints imposed on individual arms in Cartesian space due to the kinematic interactions. Dual-arm static manipulability is presented. Finally, dual-arm operational quality is scaled by a task-oriented operational quality measure (TOQs) obtained by the comparison between the desired and actual static manipulabilities. TOQs is used in the optimization of dual-arm joint configurations. Simulation results are shown.

  4. Testing the Limits of Optimizing Dual-Task Performance in Younger and Older Adults

    PubMed Central

    Strobach, Tilo; Frensch, Peter; Müller, Herrmann Josef; Schubert, Torsten

    2012-01-01

    Impaired dual-task performance in younger and older adults can be improved with practice. Optimal conditions even allow for a (near) elimination of this impairment in younger adults. However, it is unknown whether such (near) elimination is the limit of performance improvements in older adults. The present study tests this limit in older adults under conditions of (a) a high amount of dual-task training and (b) training with simplified component tasks in dual-task situations. The data showed that a high amount of dual-task training in older adults provided no evidence for an improvement of dual-task performance to the optimal dual-task performance level achieved by younger adults. However, training with simplified component tasks in dual-task situations exclusively in older adults provided a similar level of optimal dual-task performance in both age groups. Therefore through applying a testing the limits approach, we demonstrated that older adults improved dual-task performance to the same level as younger adults at the end of training under very specific conditions. PMID:22408613

  5. Dual band metamaterial perfect absorber based on artificial dielectric "molecules".

    PubMed

    Liu, Xiaoming; Lan, Chuwen; Li, Bo; Zhao, Qian; Zhou, Ji

    2016-07-13

    Dual band metamaterial perfect absorbers with two absorption bands are highly desirable because of their potential application areas such as detectors, transceiver system, and spectroscopic imagers. However, most of these dual band metamaterial absorbers proposed were based on resonances of metal patterns. Here, we numerically and experimentally demonstrate a dual band metamaterial perfect absorber composed of artificial dielectric "molecules" with high symmetry. The artificial dielectric "molecule" consists of four "atoms" of two different sizes corresponding to two absorption bands with near unity absorptivity. Numerical and experimental absorptivity verify that the dual-band metamaterial absorber is polarization insensitive and can operate in wide-angle incidence.

  6. Dual-fuel natural gas/diesel engines: Technology, performance, and emissions

    NASA Astrophysics Data System (ADS)

    Turner, S. H.; Weaver, C. S.

    1994-11-01

    An investigation of current dual-fuel natural gas/diesel engine design, performance, and emissions was conducted. The most pressing technological problems associated with dual-fuel engine use were identified along with potential solutions. It was concluded that dual-fuel engines can achieve low NO(sub x) and particulate emissions while retaining fuel-efficiency and BMEP levels comparable to those of diesel engines. The investigation also examined the potential economic impact of dual-fuel engines in diesel-electric locomotives, marine vessels, farm equipment, construction, mining, and industrial equipment, and stand-alone electricity generation systems. Recommendations for further additional funding to support research, development, and demonstration in these applications were then presented.

  7. Dual-foci detection in photoacoustic computed tomography with coplanar light illumination and acoustic detection: a phantom study.

    PubMed

    Lin, Xiangwei; Liu, Chengbo; Meng, Jing; Gong, Xiaojing; Lin, Riqiang; Sun, Mingjian; Song, Liang

    2018-05-01

    A dual-foci transducer with coplanar light illumination and acoustic detection was applied for the first time. It overcame the small directivity angle, low-sensitivity, and large datasets in conventional circular scanning or array-based photoacoustic computed tomography (PACT). The custom-designed transducer is focused on both the scanning plane with virtual-point detection and the elevation direction for large field of view (FOV) cross-sectional imaging. Moreover, a coplanar light illumination and acoustic detection configuration can provide ring-shaped light irradiation with highly efficient acoustic detection, which in principle has a better adaptability when imaging samples of irregular surfaces. Phantom experiments showed that our PACT system can achieve high resolution (∼0.5  mm), enhanced signal-to-noise ratio (16-dB improvement), and a more complete structure in a greater FOV with an equal number of sampling points compared with the results from a flat aperture transducer. This study provides the proof of concept for the fabrication of a sparse array with the dual-foci property and large aperture size for high-quality, low-cost, and high-speed photoacoustic imaging. (2018) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE).

  8. Power-efficient dual-rate optical transceiver.

    PubMed

    Zuo, Yongrong; Kiamiley, Fouad E; Wang, Xiaoqing; Gui, Ping; Ekman, Jeremy; Wang, Xingle; McFadden, Michael J; Haney, Michael W

    2005-11-20

    A dual-rate (2 Gbit/s and 100 Mbit/s) optical transceiver designed for power-efficient connections within and between modern high-speed digital systems is described. The transceiver can dynamically adjust its data rate according to performance requirements, allowing for power-on-demand operation. Dynamic power management permits energy saving and lowers device operating temperatures, improving the reliability and lifetime of optoelectronic-devices such as vertical-cavity surface-emitting lasers (VCSELs). To implement dual-rate functionality, we include in the transmitter and receiver circuits separate high-speed and low-power data path modules. The high-speed module is designed for gigabit operation to achieve high bandwidth. A simpler low-power module is designed for megabit data transmission with low power consumption. The transceiver is fabricated in a 0.5 microm silicon-on-sapphire complementary metal-oxide semiconductor. The VCSEL and photodetector devices are attached to the transceiver's integrated circuit by flip-chip bonding. A free-space optical link system is constructed to demonstrate correct dual-rate functionality. Experimental results show reliable link operation at 2 Gbit/s and 100 Mbit/s data transfer rates with approximately 104 and approximately 9 mW power consumption, respectively. The transceiver's switching time between these two data rates is demonstrated as 10 micros, which is limited by on-chip register reconfiguration time. Improvement of this switching time can be obtained by use of dedicated input-output pads for dual-rate control signals.

  9. [Dual Pathology in General Population of Itagüí, Colombia].

    PubMed

    Castaño Pérez, Guillermo A; Sierra Hincapié, Gloria Maria

    2016-01-01

    To study the prevalence of dual diagnosis (presence of a substance use disorder and an associated mental disorder) in the general population of a small town in the department of Antioquia in Colombia, through secondary analysis of survey data on Mental Health held in this city in 2011. With a sample of 415 subjects, the interview Composite International Diagnostic Interview (CIDI), WHO CAPI version, was used and statistical analysis was performed using SPSS v.21. The prevalence of dual diagnosis, considering that the presence of a diagnosis of mental disorder and a disorder snuff use of different substances was 7.2%. Substances with higher prevalence of use in life for individuals with dual diagnosis were alcohol (96.7%), marijuana (80.0%), cocaine and derivatives (33.3%), heroin (23.3%) and finally no prescription tranquilizers (13.3%), finding statistical association between drug use and dual diagnosis. Major depression (40%), oppositional defiant disorder (36.7%), posttraumatic stress (33.3%), specific phobia and attention deficit (26.7%) are the most prevalent disorders in individuals with dual diagnosis of this sample. Alcohol or drugs consumption and fulfilling diagnostic criteria for dual diagnosis have a significant statistical association for consumption of drugs like marijuana, cocaine, heroin and prescription medications (P<0.001), all with disparity ratios of >1.00, very high when the drug is heroin consumed (RD=38.754) or non-prescription medications (RD=29.462). A family history of disease and drug use has a high statistical association with dual diagnosis, with a higher association with a history of mental illness (P<.001; RD=3.677). The study reports on the prevalence of subjects with dual diagnosis in a Colombian population. Alcohol, marijuana, cocaine and heroin are derivatives and substances mostly consumed by these patients and the most prevalent mental disorders are depression, TOD and posttraumatic stress. These findings motivate clinicians to

  10. Comparison study of noise reduction algorithms in dual energy chest digital tomosynthesis

    NASA Astrophysics Data System (ADS)

    Lee, D.; Kim, Y.-S.; Choi, S.; Lee, H.; Choi, S.; Kim, H.-J.

    2018-04-01

    Dual energy chest digital tomosynthesis (CDT) is a recently developed medical technique that takes advantage of both tomosynthesis and dual energy X-ray images. However, quantum noise, which occurs in dual energy X-ray images, strongly interferes with diagnosis in various clinical situations. Therefore, noise reduction is necessary in dual energy CDT. In this study, noise-compensating algorithms, including a simple smoothing of high-energy images (SSH) and anti-correlated noise reduction (ACNR), were evaluated in a CDT system. We used a newly developed prototype CDT system and anthropomorphic chest phantom for experimental studies. The resulting images demonstrated that dual energy CDT can selectively image anatomical structures, such as bone and soft tissue. Among the resulting images, those acquired with ACNR showed the best image quality. Both coefficient of variation and contrast to noise ratio (CNR) were the highest in ACNR among the three different dual energy techniques, and the CNR of bone was significantly improved compared to the reconstructed images acquired at a single energy. This study demonstrated the clinical value of dual energy CDT and quantitatively showed that ACNR is the most suitable among the three developed dual energy techniques, including standard log subtraction, SSH, and ACNR.

  11. Transferability of Dual-Task Coordination Skills after Practice with Changing Component Tasks

    PubMed Central

    Schubert, Torsten; Liepelt, Roman; Kübler, Sebastian; Strobach, Tilo

    2017-01-01

    Recent research has demonstrated that dual-task performance with two simultaneously presented tasks can be substantially improved as a result of practice. Among other mechanisms, theories of dual-task practice-relate this improvement to the acquisition of task coordination skills. These skills are assumed (1) to result from dual-task practice, but not from single-task practice, and (2) to be independent from the specific stimulus and response mappings during the practice situation and, therefore, transferable to new dual task situations. The present study is the first that provides an elaborated test of these assumptions in a context with well-controllable practice and transfer situations. To this end, we compared the effects of dual-task and single-task practice with a visual and an auditory sensory-motor component task on the dual-task performance in a subsequent transfer session. Importantly, stimulus and stimulus-response mapping conditions in the two component tasks changed repeatedly during practice sessions, which prevents that automatized stimulus-response associations may be transferred from practice to transfer. Dual-task performance was found to be improved after practice with the dual tasks in contrast to the single-task practice. These findings are consistent with the assumption that coordination skills had been acquired, which can be transferred to other dual-task situations independently on the specific stimulus and response mapping conditions of the practiced component tasks. PMID:28659844

  12. Dual-Use system architecture for a space situational awareness system in Japan

    NASA Astrophysics Data System (ADS)

    Otani, Y.; Kohtake, N.; Ohkami, Y.

    The use of outer space plays a vital role in both defense and civil fields. Since the separation of space activities between civil and defense applications is extremely inefficient, the Dual-Use concept has been considered fundamental for promoting the effective use of space. To the best of the authors' knowledge, most previous studies on Dual-Use focused on the technological aspects, and very few on a system engineering approach to Dual-Use. This left some important issues untouched such as the operational aspects of a system of systems, which need to be understood in a more generic context. This paper presents the results of a conceptual study, system design and management analysis of Dual-Use system architecture. First, an outline of the Dual-Use concept will be described and a definition of Dual-Use given. The effectiveness of applying the Dual-Use system concept to Space Situational Awareness (SSA) for both defense and civil users as a system of systems will then be discussed and investigated with a stakeholders analysis, context diagram and design structure matrix method. It has demonstrated that there is a need for a Dual-Use SSA Data Center which works as a binder between defense and civil systems as well as a data policy for constructing a Dual-Use SSA system.

  13. Increased integrity of white matter pathways after dual n-back training.

    PubMed

    Salminen, Tiina; Mårtensson, Johan; Schubert, Torsten; Kühn, Simone

    2016-06-01

    Dual n-back WM training has been shown to produce broad transfer effects to different untrained cognitive functions. The task is demanding to the cognitive system because it includes a bi-modal (auditory and visual) dual-task component. A previous WM training study showed increased white matter integrity in the parietal lobe as well as the anterior part of the corpus callosum after visual n-back training. We investigated dual n-back training-related changes in white matter pathways. We anticipated dual n-back training to increase white matter integrity in pathways that connect brain regions related to WM processes. Additionally, we hypothesized that dual n-back training would produce more brain-wide white matter changes than single n-back training because of the involvement of two modalities and the additional dual-task coordination component of the task. The dual n-back training group showed increased white matter integrity (reflected as increased fractional anisotropy, FA) after training. The effects were mostly left lateralized as compared with changes from pretest to posttest in the passive and active control groups. Additionally, significant effects were observed in the anterior part of the corpus callosum, when the training group was compared with the passive control group. There were no changes in pretest to posttest FA changes between the passive and active control groups. The results therefore show that dual n-back training produces increased integrity in white matter pathways connecting different brain regions. The results are discussed in reference to the bi-modal dual-task component of the training task. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Determinants of Marital Quality in Dual Career Couples.

    ERIC Educational Resources Information Center

    Thomas, Sandra; And Others

    Dual career families were exceptions to the norm in the 1960's but have steadily increased in prevalence. Dual career professional couples (N=34) were studied to assess the determinants of marital quality and stability in their relationships. Results revealed that couples in high quality marriages reported satisfaction with all aspects of…

  15. Gray matter volume and dual-task gait performance in mild cognitive impairment.

    PubMed

    Doi, Takehiko; Blumen, Helena M; Verghese, Joe; Shimada, Hiroyuki; Makizako, Hyuma; Tsutsumimoto, Kota; Hotta, Ryo; Nakakubo, Sho; Suzuki, Takao

    2017-06-01

    Dual-task gait performance is impaired in older adults with mild cognitive impairment, but the brain substrates associated with dual-task gait performance are not well-established. The relationship between gray matter and gait speed under single-task and dual-task conditions (walking while counting backward) was examined in 560 seniors with mild cognitive impairment (non-amnestic mild cognitive impairment: n = 270; mean age = 72.4 yrs., 63.6 % women; amnestic mild cognitive impairment: n = 290; mean age = 73.4 yrs., 45.4 % women). Multivariate covariance-based analyses of magnetic resonance imaging data, adjusted for potential confounders including single-task gait speed, were performed to identify gray matter patterns associated with dual-task gait speed. There were no differences in gait speed or cognitive performance during dual-task gait between individuals with non-amnestic mild cognitive impairment and amnestic mild cognitive impairment. Overall, increased dual-task gait speed was associated with a gray matter pattern of increased volume in medial frontal gyrus, superior frontal gyrus, anterior cingulate, cingulate, precuneus, fusiform gyrus, middle occipital gyrus, inferior temporal gyrus and middle temporal gyrus. The relationship between dual-task gait speed and brain substrates also differed by mild cognitive impairment subtype. Our study revealed a pattern of gray matter regions associated with dual-task performance. Although dual-task gait performance was similar in amnestic and non-amnestic mild cognitive impairment, the gray matter patterns associated with dual-task gait performance differed by mild cognitive impairment subtype. These findings suggest that the brain substrates supporting dual-task gait performance in amnestic and non-amnestic subtypes are different, and consequently may respond differently to interventions, or require different interventions.

  16. Dual chamber arrhythmia detection in the implantable cardioverter defibrillator.

    PubMed

    Dijkman, B; Wellens, H J

    2000-10-01

    Dual chamber implantable cardioverter defibrillator (ICD) technology extended ICD therapy to more than termination of hemodynamically unstable ventricular tachyarrhythmias. It created the basis for dual chamber arrhythmia management in which dependable detection is important for treatment and prevention of both ventricular and atrial arrhythmias. Dual chamber detection algorithms were investigated in two Medtronic dual chamber ICDs: the 7250 Jewel AF (33 patients) and the 7271 Gem DR (31 patients). Both ICDs use the same PR Logic algorithm to interpret tachycardia as ventricular tachycardia (VT), supraventricular tachycardia (SVT), or dual (VT+ SVT). The accuracy of dual chamber detection was studied in 310 of 1,367 spontaneously occurring tachycardias in which rate criterion only was not sufficient for arrhythmia diagnosis. In 78 episodes there was a double tachycardia, in 223 episodes SVT was detected in the VT or ventricular fibrillation zone, and in 9 episodes arrhythmia was detected outside the boundaries of the PR Logic functioning. In 100% of double tachycardias the VT was correctly diagnosed and received priority treatment. SVT was seen in 59 (19%) episodes diagnosed as VT. The causes of inappropriate detection were (1) algorithm failure (inability to fulfill the PRDual chamber detection algorithms evaluated in a subset of diagnostically difficult arrhythmias allow safe detection of double tachycardias but require further extension and programmability to

  17. Dual-Modality, Dual-Functional Nanoprobes for Cellular and Molecular Imaging

    PubMed Central

    Menon, Jyothi U.; Gulaka, Praveen K.; McKay, Madalyn A.; Geethanath, Sairam; Liu, Li; Kodibagkar, Vikram D.

    2012-01-01

    An emerging need for evaluation of promising cellular therapies is a non-invasive method to image the movement and health of cells following transplantation. However, the use of a single modality to serve this purpose may not be advantageous as it may convey inaccurate or insufficient information. Multi-modal imaging strategies are becoming more popular for in vivo cellular and molecular imaging because of their improved sensitivity, higher resolution and structural/functional visualization. This study aims at formulating Nile Red doped hexamethyldisiloxane (HMDSO) nanoemulsions as dual modality (Magnetic Resonance Imaging/Fluorescence), dual-functional (oximetry/detection) nanoprobes for cellular and molecular imaging. HMDSO nanoprobes were prepared using a HS15-lecithin combination as surfactant and showed an average radius of 71±39 nm by dynamic light scattering and in vitro particle stability in human plasma over 24 hrs. They were found to readily localize in the cytosol of MCF7-GFP cells within 18 minutes of incubation. As proof of principle, these nanoprobes were successfully used for fluorescence imaging and for measuring pO2 changes in cells by magnetic resonance imaging, in vitro, thus showing potential for in vivo applications. PMID:23382776

  18. Dual Use of Smokeless Tobacco or E-cigarettes with Cigarettes and Cessation

    PubMed Central

    Kalkhoran, Sara; Grana, Rachel A.; Neilands, Torsten B.; Ling, Pamela M.

    2015-01-01

    Objectives To evaluate predictors of dual use of cigarettes with smokeless tobacco or e-cigarettes. Methods Adult smokers (N = 1324) completed online cross-sectional surveys. Logistic regression evaluated predictors of dual use and cigarette quit attempts. Results Smokeless tobacco dual use was associated with past attempts to quit smoking by switching to smokeless products. E-cigarette dual use was associated with using stop-smoking medication and strong anti-tobacco industry attitudes. Ever use of stop-smoking medication was associated with quit attempts among dual e-cigarette users and cigarette-only users. Conclusions Dual users are more likely than cigarette-only users to endorse certain cessation-related attitudes and behaviors. This may provide an opportunity for clinicians or others to discuss evidence-based strategies for smoking cessation. PMID:25564840

  19. Thermodynamic Analysis of Dual-Mode Scramjet Engine Operation and Performance

    NASA Technical Reports Server (NTRS)

    Riggins, David; Tacket, Regan; Taylor, Trent; Auslender, Aaron

    2006-01-01

    Recent analytical advances in understanding the performance continuum (the thermodynamic spectrum) for air-breathing engines based on fundamental second-law considerations have clarified scramjet and ramjet operation, performance, and characteristics. Second-law based analysis is extended specifically in this work to clarify and describe the performance characteristics for dual-mode scramjet operation in the mid-speed range of flight Mach 4 to 7. This is done by a fundamental investigation of the complex but predictable interplay between heat release and irreversibilities in such an engine; results demonstrate the flow and performance character of the dual mode regime and of dual mode transition behavior. Both analytical and computational (multi-dimensional CFD) studies of sample dual-mode flow-fields are performed in order to demonstrate the second-law capability and performance and operability issues. The impact of the dual-mode regime is found to be characterized by decreasing overall irreversibility with increasing heat release, within the operability limits of the system.

  20. Closed head injury and perceptual processing in dual-task situations.

    PubMed

    Hein, G; Schubert, T; von Cramon, D Y

    2005-01-01

    Using a classical psychological refractory period (PRP) paradigm we investigated whether increased interference between dual-task input processes is one possible source of dual-task deficits in patients with closed-head injury (CHI). Patients and age-matched controls were asked to give speeded motor reactions to an auditory and a visual stimulus. The perceptual difficulty of the visual stimulus was manipulated by varying its intensity. The results of Experiment 1 showed that CHI patients suffer from increased interference between dual-task input processes, which is related to the salience of the visual stimulus. A second experiment indicated that this input interference may be specific to brain damage following CHI. It is not evident in other groups of neurological patients like Parkinson's disease patients. We conclude that the non-interfering processing of input stages in dual-tasks requires cognitive control. A decline in the control of input processes should be considered as one source of dual-task deficits in CHI patients.

  1. Effects of exposure to anti-vaping public service announcements among current smokers and dual users of cigarettes and electronic nicotine delivery systems.

    PubMed

    Tan, Andy S L; Rees, Vaughan W; Rodgers, Justin; Agudile, Emeka; Sokol, Natasha A; Yie, Kyeungyeun; Sanders-Jackson, Ashley

    2018-07-01

    Anti-vaping public service announcements (PSAs) are intended to discourage vaping or use of electronic nicotine delivery systems (ENDS). However, vaping portrayals in PSAs may have unintended effects if they increase smoking or vaping urges. This study examined benefits and unintended effects of anti-vaping PSAs with vapor portrayals on smoking and vaping-related outcomes. Young adult smokers (N = 171) and dual users (N = 122) aged 21-30 years were randomly assigned to view: 1) anti-vaping PSAs with vapor; 2) anti-vaping PSAs without vapor; 3) physical activity PSAs; or 4) anti-smoking PSAs with smoking cues. Outcomes were changes in vaping and smoking urges before and after viewing PSAs, post-test vaping and smoking intentions in the next hour, and post-test intention to purchase ENDS and traditional cigarettes. Smokers only: Exposure to anti-vaping PSAs with vapor (vs. physical activity) was associated with lower intention to vape and to purchase ENDS (ps < 0.001) and lower intention to smoke and purchase cigarettes (ps < 0.05). Exposure to anti-vaping PSAs with vapor (vs. PSAs without vapor and vs. anti-smoking PSAs with smoking cues) was associated with lower intention to vape in the next hour (ps < 0.05). Exposure to anti-vaping PSAs without vapor (vs. physical activity) was associated with lower change in vaping urge (p < 0.05) and intention to purchase ENDS (p < 0.001). Dual users: Exposure to anti-vaping PSAs without vapor (vs. anti-smoking PSAs) was associated with lower intention to purchase ENDS (p < 0.05). Viewing anti-vaping PSAs with vapor was not associated with unintended effects and may have benefits on reducing smoking and vaping-related outcomes. Copyright © 2018 Elsevier B.V. All rights reserved.

  2. Dual Double-Wedge Pseudo-Depolarizer with Anamorphic PSF

    NASA Technical Reports Server (NTRS)

    Hill, Peter; Thompson, Patrick

    2012-01-01

    A polarized scene, which may occur at oblique illumination angles, creates a radiometric signal that varies as a function of viewing angle. One common optical component that is used to minimize such an effect is a polarization scrambler or depolarizer. As part of the CLARREO mission, the SOLARIS instrument project at Goddard Space Flight Center has developed a new class of polarization scramblers using a dual double-wedge pseudo-depolarizer that produces an anamorphic point spread function (PSF). The SOLARIS instrument uses two Wollaston type scramblers in series, each with a distinct wedge angle, to image a pseudo-depolarized scene that is free of eigenstates. Since each wedge is distinct, the scrambler is able to produce an anamorphic PSF that maintains high spatial resolution in one dimension by sacrificing the spatial resolution in the other dimension. This scrambler geometry is ideal for 1-D imagers, such as pushbroom slit spectrometers, which require high spectral resolution, high spatial resolution, and low sensitivity to polarized light. Moreover, the geometry is applicable to a wide range of scientific instruments that require both high SNR (signal-to-noise ratio) and low sensitivity to polarized scenes

  3. Technology, Applications, and Process Challenges of Dual Chamber Systems.

    PubMed

    Werk, Tobias; Ludwig, Imke S; Luemkemann, Joerg; Mahler, Hanns-Christian; Huwyler, Joerg; Hafner, Mathias

    2016-01-01

    Dual-chamber systems provide an option as a drug and device combination product, when home care and emergency lyophilized products are intended. Nevertheless, until today, there are only a few products on the market, due to the challenges and limitations in manufacturability, product formulation, and product stability in a dual-chamber configuration, as well as economic considerations. This review serves to describe currently available dual-chamber systems and to discuss factors to be considered for appropriate selection and establishing fill-finish processes. Copyright © 2016. Published by Elsevier Inc.

  4. Dual-opioid therapy: changing the paradigm. Introduction.

    PubMed

    Nicholson, Bruce D

    2012-03-01

    Morphine sulfate and oxycodone hydrochloride are commonly used for pain management because of their pharmacologic profile, pharmacokinetics, and analgesic potency. However, opioids are associated with a significant adverse event (AE) burden that limits their use in both the acute and the chronic pain settings. Co-administration of opioids demonstrated synergistic analgesia and reduced side effects. Thus, dual-opioid therapy has the potential to enhance the positive analgesic benefits of opioids, while limiting the burden of opioid-related AEs. This symposium proceedings was based on presentations at the 13th World Congress on Pain in August 2010. This program will review the rationale for dual-opioid therapy based on preclinical findings and data from clinical studies showing the efficacy and tolerability profile of a dual-opioid formulation when used to treat acute postoperative pain. Wiley Periodicals, Inc.

  5. Dual Credit, College Type, and Enhanced Degree Attainment

    ERIC Educational Resources Information Center

    Blankenberger, Bob; Lichtenberger, Eric; Witt, M. Allison

    2017-01-01

    In this study, we analyzed data for the Illinois high school class of 2003 to determine the impact of dual credit participation on postsecondary attainment. We matched 8,095 dual credit participants to an equal number of nonparticipants within the same high school at the point of postsecondary enrollment using propensity scores calculated through…

  6. 26 CFR 1.1503-2 - Dual consolidated loss.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 12 2011-04-01 2011-04-01 false Dual consolidated loss. 1.1503-2 Section 1.1503-2 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES (CONTINUED) Administrative Provisions and Other Rules § 1.1503-2 Dual consolidated loss. (a) Purpose and scope. This section...

  7. Using dual-purpose crops in sheep-grazing systems.

    PubMed

    Dove, Hugh; Kirkegaard, John

    2014-05-01

    The utilisation of dual-purpose crops, especially wheat and canola grown for forage and grain production in sheep-grazing systems, is reviewed. When sown early and grazed in winter before stem elongation, later-maturing wheat and canola crops can be grazed with little impact on grain yield. Recent research has sought to develop crop- and grazing-management strategies for dual-purpose crops. Aspects examined have been grazing effects on crop growth, recovery and yield development along with an understanding of the grazing value of the crop fodder, its implications for animal nutrition and grazing management to maximise live-weight gain. By alleviating the winter 'feed gap', the increase in winter stocking rate afforded by grazing crops allows crop and livestock production to be increased simultaneously on the same farm. Integration of dual-purpose wheat with canola on mixed farms provides further systems advantages related to widened operational windows, weed and disease control and risk management. Dual-purpose crops are an innovation that has potential to assist in addressing the global food-security challenge. © 2013 Society of Chemical Industry.

  8. Intercomparison of Evapotranspiration Over the Savannah Volta Basin in West Africa Using Remote Sensing Data

    PubMed Central

    Opoku-Duah, S.; Donoghue, D.N.M.; Burt, T. P.

    2008-01-01

    This paper compares evapotranspiration estimates from two complementary satellite sensors – NASA's Moderate Resolution Imaging Spectroradiometer (MODIS) and ESA's ENVISAT Advanced Along-Track Scanning Radiometer (AATSR) over the savannah area of the Volta basin in West Africa. This was achieved through solving for evapotranspiration on the basis of the regional energy balance equation, which was computationally-driven by the Surface Energy Balance Algorithm for Land algorithm (SEBAL). The results showed that both sensors are potentially good sources of evapotranspiration estimates over large heterogeneous landscapes. The MODIS sensor measured daily evapotranspiration reasonably well with a strong spatial correlation (R2=0.71) with Landsat ETM+ but underperformed with deviations up to ∼2.0 mm day-1, when compared with local eddy correlation observations and the Penman-Monteith method mainly because of scale mismatch. The AATSR sensor produced much poorer correlations (R2=0.13) with Landsat ETM+ and conventional ET methods also because of differences in atmospheric correction and sensor calibration over land. PMID:27879847

  9. Bistability in dual-frequency nematic liquid crystals

    NASA Astrophysics Data System (ADS)

    Palto, S. P.; Barnik, M. I.

    2007-03-01

    Different modes of bistable switching in liquid crystals with frequency inversion of the dielectric anisotropy sign are discussed. The study is performed by numerical simulation and experimentally. It is shown that dual frequency driving can be effectively used to control switching between topologically equivalent and non-equivalent director field distributions. The experimental results on temperature performance of the dual-frequency switching and possible driving methods for energy consumption and expanding the temperature range are presented.

  10. Aerosol Climate Time Series Evaluation In ESA Aerosol_cci

    NASA Astrophysics Data System (ADS)

    Popp, T.; de Leeuw, G.; Pinnock, S.

    2015-12-01

    Within the ESA Climate Change Initiative (CCI) Aerosol_cci (2010 - 2017) conducts intensive work to improve algorithms for the retrieval of aerosol information from European sensors. By the end of 2015 full mission time series of 2 GCOS-required aerosol parameters are completely validated and released: Aerosol Optical Depth (AOD) from dual view ATSR-2 / AATSR radiometers (3 algorithms, 1995 - 2012), and stratospheric extinction profiles from star occultation GOMOS spectrometer (2002 - 2012). Additionally, a 35-year multi-sensor time series of the qualitative Absorbing Aerosol Index (AAI) together with sensitivity information and an AAI model simulator is available. Complementary aerosol properties requested by GCOS are in a "round robin" phase, where various algorithms are inter-compared: fine mode AOD, mineral dust AOD (from the thermal IASI spectrometer), absorption information and aerosol layer height. As a quasi-reference for validation in few selected regions with sparse ground-based observations the multi-pixel GRASP algorithm for the POLDER instrument is used. Validation of first dataset versions (vs. AERONET, MAN) and inter-comparison to other satellite datasets (MODIS, MISR, SeaWIFS) proved the high quality of the available datasets comparable to other satellite retrievals and revealed needs for algorithm improvement (for example for higher AOD values) which were taken into account for a reprocessing. The datasets contain pixel level uncertainty estimates which are also validated. The paper will summarize and discuss the results of major reprocessing and validation conducted in 2015. The focus will be on the ATSR, GOMOS and IASI datasets. Pixel level uncertainties validation will be summarized and discussed including unknown components and their potential usefulness and limitations. Opportunities for time series extension with successor instruments of the Sentinel family will be described and the complementarity of the different satellite aerosol products

  11. 17 years of aerosol and clouds from the ATSR Series of Instruments

    NASA Astrophysics Data System (ADS)

    Poulsen, C. A.

    2015-12-01

    Aerosols play a significant role in Earth's climate by scattering and absorbing incoming sunlight and affecting the formation and radiative properties of clouds. The extent to which aerosols affect cloud remains one of the largest sources of uncertainty amongst all influences on climate change. Now, a new comprehensive datasets has been developed under the ESA Climate Change Initiative (CCI) programme to quantify how changes in aerosol levels affect these clouds. The unique dataset is constructed from the Optimal Retrieval of Aerosol and Cloud (ORAC) algorithm used in (A)ATSR (Along Track Scanning Radiometer) retrievals of aerosols generated in the Aerosol CCI and the CC4CL ( Community Code for CLimate) for cloud retrieval in the Cloud CCI. The ATSR instrument is a dual viewing instrument with on board visible and infra red calibration systems making it an ideal instrument to study trends of Aerosol and Clouds and their interactions. The data set begins in 1995 and ends in 2012. A new instrument in the series SLSTR(Sea and Land Surface Temperature Radiometer) will be launch in 2015. The Aerosol and Clouds are retreived using similar algorithms to maximise the consistency of the results These state-of-the-art retrievals have been merged together to quantify the susceptibility of cloud properties to changes in aerosol concentration. Aerosol-cloud susceptibilities are calculated from several thousand samples in each 1x1 degree globally gridded region. Two-D histograms of the aerosol and cloud properties are also included to facilitate seamless comparisons between other satellite and modelling data sets. The analysis of these two long term records will be discussed individually and the initial comparisons between these new joint products and models will be presented.

  12. Spatiotemporal Targeting of a Dual-Ligand Nanoparticle to Cancer Metastasis.

    PubMed

    Doolittle, Elizabeth; Peiris, Pubudu M; Doron, Gilad; Goldberg, Amy; Tucci, Samantha; Rao, Swetha; Shah, Shruti; Sylvestre, Meilyn; Govender, Priya; Turan, Oguz; Lee, Zhenghong; Schiemann, William P; Karathanasis, Efstathios

    2015-08-25

    Various targeting strategies and ligands have been employed to direct nanoparticles to tumors that upregulate specific cell-surface molecules. However, tumors display a dynamic, heterogeneous microenvironment, which undergoes spatiotemporal changes including the expression of targetable cell-surface biomarkers. Here, we investigated a dual-ligand nanoparticle to effectively target two receptors overexpressed in aggressive tumors. By using two different chemical specificities, the dual-ligand strategy considered the spatiotemporal alterations in the expression patterns of the receptors in cancer sites. As a case study, we used two mouse models of metastasis of triple-negative breast cancer using the MDA-MB-231 and 4T1 cells. The dual-ligand system utilized two peptides targeting P-selectin and αvβ3 integrin, which are functionally linked to different stages of the development of metastatic disease at a distal site. Using in vivo multimodal imaging and post mortem histological analyses, this study shows that the dual-ligand nanoparticle effectively targeted metastatic disease that was otherwise missed by single-ligand strategies. The dual-ligand nanoparticle was capable of capturing different metastatic sites within the same animal that overexpressed either receptor or both of them. Furthermore, the highly efficient targeting resulted in 22% of the injected dual-ligand nanoparticles being deposited in early-stage metastases within 2 h after injection.

  13. Inorganic dual-layer microporous supported membranes

    DOEpatents

    Brinker, C. Jeffrey; Tsai, Chung-Yi; Lu, Yungfeng

    2003-03-25

    The present invention provides for a dual-layer inorganic microporous membrane capable of molecular sieving, and methods for production of the membranes. The inorganic microporous supported membrane includes a porous substrate which supports a first inorganic porous membrane having an average pore size of less than about 25 .ANG. and a second inorganic porous membrane coating the first inorganic membrane having an average pore size of less than about 6 .ANG.. The dual-layered membrane is produced by contacting the porous substrate with a surfactant-template polymeric sol, resulting in a surfactant sol coated membrane support. The surfactant sol coated membrane support is dried, producing a surfactant-templated polymer-coated substrate which is calcined to produce an intermediate layer surfactant-templated membrane. The intermediate layer surfactant-templated membrane is then contacted with a second polymeric sol producing a polymeric sol coated substrate which is dried producing an inorganic polymeric coated substrate. The inorganic polymeric coated substrate is then calcined producing an inorganic dual-layered microporous supported membrane in accordance with the present invention.

  14. Tunable metamaterial dual-band terahertz absorber

    NASA Astrophysics Data System (ADS)

    Luo, C. Y.; Li, Z. Z.; Guo, Z. H.; Yue, J.; Luo, Q.; Yao, G.; Ji, J.; Rao, Y. K.; Li, R. K.; Li, D.; Wang, H. X.; Yao, J. Q.; Ling, F. R.

    2015-11-01

    We report a design of a temperature controlled tunable dual band terahertz absorber. The compact single unit cell consists of two nested closed square ring resonators and a layer metallic separated by a substrate strontium titanate (STO) dielectric layer. It is found that the absorber has two distinctive absorption peaks at frequencies 0.096 THz and 0.137 THz, whose peaks are attained 97% and 75%. Cooling the absorber from 400 K to 250 K causes about 25% and 27% shift compared to the resonance frequency of room temperature, when we cooling the temperature to 150 K, we could attained both the two tunabilities exceeding 53%. The frequency tunability is owing to the variation of the dielectric constant of the low-temperature co-fired ceramic (LTCC) substrate. The mechanism of the dual band absorber is attributed to the overlapping of dual resonance frequencies, and could be demonstrated by the distributions of the electric field. The method opens up avenues for designing tunable terahertz devices in detection, imaging, and stealth technology.

  15. A Dual System Model of Preferences under Risk

    ERIC Educational Resources Information Center

    Mukherjee, Kanchan

    2010-01-01

    This article presents a dual system model (DSM) of decision making under risk and uncertainty according to which the value of a gamble is a combination of the values assigned to it independently by the affective and deliberative systems. On the basis of research on dual process theories and empirical research in Hsee and Rottenstreich (2004) and…

  16. 34 CFR 75.519 - Dual compensation of staff.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 34 Education 1 2011-07-01 2011-07-01 false Dual compensation of staff. 75.519 Section 75.519... by a Grantee? Project Staff § 75.519 Dual compensation of staff. A grantee may not use its grantee to pay a project staff member for time or work for which that staff member is compensated from some other...

  17. 34 CFR 75.519 - Dual compensation of staff.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 34 Education 1 2014-07-01 2014-07-01 false Dual compensation of staff. 75.519 Section 75.519... by a Grantee? Project Staff § 75.519 Dual compensation of staff. A grantee may not use its grantee to pay a project staff member for time or work for which that staff member is compensated from some other...

  18. 34 CFR 75.519 - Dual compensation of staff.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 34 Education 1 2012-07-01 2012-07-01 false Dual compensation of staff. 75.519 Section 75.519... by a Grantee? Project Staff § 75.519 Dual compensation of staff. A grantee may not use its grantee to pay a project staff member for time or work for which that staff member is compensated from some other...

  19. 34 CFR 75.519 - Dual compensation of staff.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 34 Education 1 2013-07-01 2013-07-01 false Dual compensation of staff. 75.519 Section 75.519... by a Grantee? Project Staff § 75.519 Dual compensation of staff. A grantee may not use its grantee to pay a project staff member for time or work for which that staff member is compensated from some other...

  20. 34 CFR 75.519 - Dual compensation of staff.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 34 Education 1 2010-07-01 2010-07-01 false Dual compensation of staff. 75.519 Section 75.519... by a Grantee? Project Staff § 75.519 Dual compensation of staff. A grantee may not use its grantee to pay a project staff member for time or work for which that staff member is compensated from some other...

  1. Analysis of Dual Mode Systems in an Urban Area : Volume 1. Summary.

    DOT National Transportation Integrated Search

    1973-12-01

    Various forms of Dual Mode transportation were analyzed in order to assess the economic viability of the dual mode concept. Specially designed new small Dual Mode vehicles, modifications of existing automobiles, and pallet systems, all operating in c...

  2. Motor-cognitive dual-task deficits in individuals with early-mid stage Huntington disease.

    PubMed

    Fritz, Nora E; Hamana, Katy; Kelson, Mark; Rosser, Anne; Busse, Monica; Quinn, Lori

    2016-09-01

    Huntington disease (HD) results in a range of cognitive and motor impairments that progress throughout the disease stages; however, little research has evaluated specific dual-task abilities in this population, and the degree to which they may be related to functional ability. The purpose of this study was to a) examine simple and complex motor-cognitive dual-task performance in individuals with HD, b) determine relationships between dual-task walking ability and disease-specific measures of motor, cognitive and functional ability, and c) examine the relationship of dual-task measures to falls in individuals with HD. Thirty-two individuals with HD were evaluated for simple and complex dual-task ability using the Walking While Talking Test. Demographics and disease-specific measures of motor, cognitive and functional ability were also obtained. Individuals with HD had impairments in simple and complex dual-task ability. Simple dual-task walking was correlated to disease-specific motor scores as well as cognitive performance, but complex dual-task walking was correlated with total functional capacity, as well as a range of cognitive measures. Number of prospective falls was moderately-strongly correlated to dual-task measures. Our results suggest that individuals with HD have impairments in cognitive-motor dual-task ability that are related to disease progression and specifically functional ability. Dual-task measures appear to evaluate a unique construct in individuals with early to mid-stage HD, and may have value in improving the prediction of falls risk in this population. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Acquisition, Conservation, and Loss of Dual-Targeted Proteins in Land Plants1[W][OA

    PubMed Central

    Xu, Lin; Carrie, Chris; Law, Simon R.; Murcha, Monika W.; Whelan, James

    2013-01-01

    The dual-targeting ability of a variety of proteins from Physcomitrella patens, rice (Oryza sativa), and Arabidopsis (Arabidopsis thaliana) was tested to determine when dual targeting arose and to what extent it was conserved in land plants. Overall, the targeting ability of over 80 different proteins from rice and P. patens, representing 42 dual-targeted proteins in Arabidopsis, was tested. We found that dual targeting arose early in land plant evolution, as it was evident in many cases with P. patens proteins that were conserved in rice and Arabidopsis. Furthermore, we found that the acquisition of dual-targeting ability is still occurring, evident in P. patens as well as rice and Arabidopsis. The loss of dual-targeting ability appears to be rare, but does occur. Ascorbate peroxidase represents such an example. After gene duplication in rice, individual genes encode proteins that are targeted to a single organelle. Although we found that dual targeting was generally conserved, the ability to detect dual-targeted proteins differed depending on the cell types used. Furthermore, it appears that small changes in the targeting signal can result in a loss (or gain) of dual-targeting ability. Overall, examination of the targeting signals within this study did not reveal any clear patterns that would predict dual-targeting ability. The acquisition of dual-targeting ability also appears to be coordinated between proteins. Mitochondrial intermembrane space import and assembly protein40, a protein involved in oxidative folding in mitochondria and peroxisomes, provides an example where acquisition of dual targeting is accompanied by the dual targeting of substrate proteins. PMID:23257241

  4. Dual-band quantum well infrared photodetector with metallic structure

    NASA Astrophysics Data System (ADS)

    Wu, Yang; Liu, Hongmei; Li, Pingzhou

    2018-02-01

    The quantum efficiency of the dual bands quantum well infrared photodetectors(QWIP) has been widely concerned in recent years. A novel structure for the dual-band quantum well infrared detectors which is based on GaAs/AlGaAs designed in this paper is aimed to improve the absorption efficiency. The structure replaces the conventional grating with a metallic grating based on surface plasmon polaritons(SPPS), and we further insert a metal structure in the periodic quantum well layer. The simulation result shows that the use of the different shapes of the metal holes can remarkably improve the optical coupling efficiency due to the surface plasmon effect. By optimizing parameters of the structure, it can work in the dual infrared bands of 3-5um and 8-12um. Moreover, the absorption rate increased by 20% compared with traditional structure of Dual-band QWIP.

  5. On the dual equivalence of the self-dual and topologically massive /p-form models

    NASA Astrophysics Data System (ADS)

    Menezes, R.; Nascimento, J. R. S.; Ribeiro, R. F.; Wotzasek, C.

    2003-07-01

    We study the duality symmetry in p-form models containing a generalized Bq∧Fp+1 term in spacetime manifolds of arbitrary dimensions. The equivalence between the Bq∧Fp+1 self-dual (SDB∧F) and the Bq∧Fp+1 topologically massive (TMB∧F) models is established using a gauge embedding procedure, including the minimal coupling to conserved charged matter current. The minimal coupling adopted for both tensor fields in the self-dual representation is transformed into a non-minimal magnetic like coupling in the topologically massive representation but with the currents swapped. It is known that to establish this equivalence a current-current interaction term is needed to render the matter sector unchanged. We show that both terms arise naturally from the embedding adopted. Comparison with Higgs/Julia-Toulouse duality is established.

  6. Dual-readout calorimetry

    NASA Astrophysics Data System (ADS)

    Lee, Sehwook; Livan, Michele; Wigmans, Richard

    2018-04-01

    In the past 20 years, dual-readout calorimetry has emerged as a technique for measuring the properties of high-energy hadrons and hadron jets that offers considerable advantages compared with the instruments that are currently used for this purpose in experiments at the high-energy frontier. The status of this experimental technique and the challenges faced for its further development are reviewed.

  7. An Inertial Dual-State State Estimator for Precision Planetary Landing with Hazard Detection and Avoidance

    NASA Technical Reports Server (NTRS)

    Bishop, Robert H.; DeMars, Kyle; Trawny, Nikolas; Crain, Tim; Hanak, Chad; Carson, John M.; Christian, John

    2016-01-01

    The navigation filter architecture successfully deployed on the Morpheus flight vehicle is presented. The filter was developed as a key element of the NASA Autonomous Landing and Hazard Avoidance Technology (ALHAT) project and over the course of 15 free fights was integrated into the Morpheus vehicle, operations, and flight control loop. Flight testing completed by demonstrating autonomous hazard detection and avoidance, integration of an altimeter, surface relative velocity (velocimeter) and hazard relative navigation (HRN) measurements into the onboard dual-state inertial estimator Kalman flter software, and landing within 2 meters of the vertical testbed GPS-based navigation solution at the safe landing site target. Morpheus followed a trajectory that included an ascent phase followed by a partial descent-to-landing, although the proposed filter architecture is applicable to more general planetary precision entry, descent, and landings. The main new contribution is the incorporation of a sophisticated hazard relative navigation sensor-originally intended to locate safe landing sites-into the navigation system and employed as a navigation sensor. The formulation of a dual-state inertial extended Kalman filter was designed to address the precision planetary landing problem when viewed as a rendezvous problem with an intended landing site. For the required precision navigation system that is capable of navigating along a descent-to-landing trajectory to a precise landing, the impact of attitude errors on the translational state estimation are included in a fully integrated navigation structure in which translation state estimation is combined with attitude state estimation. The map tie errors are estimated as part of the process, thereby creating a dual-state filter implementation. Also, the filter is implemented using inertial states rather than states relative to the target. External measurements include altimeter, velocimeter, star camera, terrain relative

  8. Adverse effects in dual-feed interferometry

    NASA Astrophysics Data System (ADS)

    Colavita, M. Mark

    2009-11-01

    Narrow-angle dual-star interferometric astrometry can provide very high accuracy in the presence of the Earth's turbulent atmosphere. However, to exploit the high atmospherically-limited accuracy requires control of systematic errors in measurement of the interferometer baseline, internal OPDs, and fringe phase. In addition, as high photometric SNR is required, care must be taken to maximize throughput and coherence to obtain high accuracy on faint stars. This article reviews the key aspects of the dual-star approach and implementation, the main contributors to the systematic error budget, and the coherence terms in the photometric error budget.

  9. Dual-Gated Motion-Frozen Cardiac PET with Flurpiridaz F 18.

    PubMed

    Slomka, Piotr J; Rubeaux, Mathieu; Le Meunier, Ludovic; Dey, Damini; Lazewatsky, Joel L; Pan, Tinsu; Dweck, Marc R; Newby, David E; Germano, Guido; Berman, Daniel S

    2015-12-01

    A novel PET radiotracer, Flurpiridaz F 18, has undergone phase II clinical trial evaluation as a high-resolution PET cardiac perfusion imaging agent. In a subgroup of patients imaged with this agent, we assessed the feasibility and benefit of simultaneous correction of respiratory and cardiac motion. In 16 patients, PET imaging was performed on a 4-ring scanner in dual cardiac and respiratory gating mode. Four sets of data were reconstructed with high-definition reconstruction (HD•PET): ungated and 8-bin electrocardiography-gated images using 5-min acquisition, optimal respiratory gating (ORG)-as developed for oncologic imaging-using a narrow range of breathing amplitude around end-expiration level with 35% of the counts in a 7-min acquisition, and 4-bin respiration-gated and 8-bin electrocardiography-gated images (32 bins in total) using the 7-min acquisition (dual-gating, using all data). Motion-frozen (MF) registration algorithms were applied to electrocardiography-gated and dual-gated data, creating cardiac-MF and dual-MF images. We computed wall thickness, wall/cavity contrast, and contrast-to-noise ratio for standard, ORG, cardiac-MF, and dual-MF images to assess image quality. The wall/cavity contrast was similar for ungated (9.3 ± 2.9) and ORG (9.5 ± 3.2) images and improved for cardiac-MF (10.8 ± 3.6) and dual-MF images (14.8 ± 8.0) (P < 0.05). The contrast-to-noise ratio was 22.2 ± 9.1 with ungated, 24.7 ± 12.2 with ORG, 35.5 ± 12.8 with cardiac-MF, and 42.1 ± 13.2 with dual-MF images (all P < 0.05). The wall thickness was significantly decreased (P < 0.05) with dual-MF (11.6 ± 1.9 mm) compared with ungated (13.9 ± 2.8 mm), ORG (13.1 ± 2.9 mm), and cardiac-MF images (12.1 ± 2.7 mm). Dual (respiratory/cardiac)-gated perfusion imaging with Flurpiridaz F 18 is feasible and improves image resolution, contrast, and contrast-to-noise ratio when MF registration methods are applied. © 2015 by the Society of Nuclear Medicine and Molecular Imaging

  10. The Grassmannian origin of dual superconformal invariance

    NASA Astrophysics Data System (ADS)

    Arkani-Hamed, Nima; Cachazo, Freddy; Cheung, Clifford

    2010-03-01

    A dual formulation of the S Matrix for mathcal {N} = 4 SYM has recently been presented, where all leading singularities of n-particle N k-2MHV amplitudes are given as an integral over the Grassmannian G( k, n), with cyclic symmetry, parity and superconformal invariance manifest. In this short note we show that the dual superconformal invariance of this object is also manifest. The geometry naturally suggests a partial integration and simple change of variable to an integral over G( k - 2, n). This change of variable precisely corresponds to the mapping between usual momentum variables and the “momentum twistors” introduced by Hodges, and yields an elementary derivation of the momentumtwistor space formula very recently presented by Mason and Skinner, which is manifestly dual superconformal invariant. Thus the G( k, n) Grassmannian formulation allows a direct understanding of all the important symmetries of mathcal {N} = 4 SYM scattering amplitudes.

  11. [Treatment program for dual-diagnosis substance abusers].

    PubMed

    Kandel, Isack

    2007-01-01

    Dual-diagnosis mentally ill patients, i.e. those characterized with substance abuse problems combined with mental health problems, are a challenge both for systems treating substance abusers and for mental health services. These patients are not easily integrated in either of these healthcare systems and/or are treated only for one aspect of their problem by each of these systems. For such patients it is necessary to create a separate treatment model, combining care of the problem of substance abuse and attention to the patient's mental pathology, according to his individual personality traits. For purposes of this programme a treatment setting operating on the model of a therapeutic community is proposed. This setting will open an affiliated treatment programme for dual-diagnosed patients in a separate treatment programme that is not part of the therapeutic community but will be affiliated with it and will accept dual-diagnosis patients.

  12. Cognitive structure, flexibility, and plasticity in human multitasking-An integrative review of dual-task and task-switching research.

    PubMed

    Koch, Iring; Poljac, Edita; Müller, Hermann; Kiesel, Andrea

    2018-06-01

    Numerous studies showed decreased performance in situations that require multiple tasks or actions relative to appropriate control conditions. Because humans often engage in such multitasking activities, it is important to understand how multitasking affects performance. In the present article, we argue that research on dual-task interference and sequential task switching has proceeded largely separately using different experimental paradigms and methodology. In our article we aim at organizing this complex set of research in terms of three complementary research perspectives on human multitasking. One perspective refers to structural accounts in terms of cognitive bottlenecks (i.e., critical processing stages). A second perspective refers to cognitive flexibility in terms of the underlying cognitive control processes. A third perspective emphasizes cognitive plasticity in terms of the influence of practice on human multitasking abilities. With our review article we aimed at highlighting the value of an integrative position that goes beyond isolated consideration of a single theoretical research perspective and that broadens the focus from single experimental paradigms (dual task and task switching) to favor instead a view that emphasizes the fundamental similarity of the underlying cognitive mechanisms across multitasking paradigms. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  13. The Beliefs, Attitudes and Views of University Students about Anger and the Effects of Cognitive Behavioral Therapy-Oriented Anger Control and Anxiety Management Programs on Their Anger Management Skill Levels

    ERIC Educational Resources Information Center

    Karahan, T. Fikret; Yalçin, B. Murat; Erbas, Melda M.

    2014-01-01

    This study was designed as a qualitative focus group using a randomized controlled trail with a mixed methodology. The study has dual aims. First we searched the beliefs, attitudes and views of 176 university students on how to deal with anger using eight focus discussion groups. The anxiety and anger levels of these students were investigated…

  14. Does dual-task coordination performance decline in later life?

    PubMed

    Sebastián, María V; Mediavilla, Roberto

    2017-05-01

    This cross-sectional study examined whether changes occur in people’s capacity to coordinate two simultaneous tasks (dual-task) when transitioning from adulthood to later life. The central executive, Baddeley’s working memory model component, is responsible for this coordination. Contradictory results have been reported regarding the relationship between ageing and dual-task performance; but these seem to be related to methodological issues that have been addressed in this study. Nine hundred and seventy-two participants, aged between 35 and 90 years old, volunteered to carry out a verbal digit span task, followed by single and concurrent (dual-task) tests: first, a box crossing task, then, the digit recall task in relation to their memory span, and finally, both these tests simultaneously. We found no difference in people’s capacity to coordinate their attention when doing two tasks in adulthood or healthy later life, including those in the oldest age groups. Furthermore, gender and educational level were not related to dual-task performance. The results support the normal functioning of the central executive in very old people. These data contrast with research with patients suffering from different types of dementia, which show a decrease in their dual-task performance.

  15. Dual-Alloy Disks are Formed by Powder Metallurgy

    NASA Technical Reports Server (NTRS)

    Harf, F. H.; Miner, R. V.; Kortovich, C. S.; Marder, J. M.

    1982-01-01

    High-performance disks have widely varying properties from hub to rim. Dual property disk is fabricated using two nickel-base alloys, AF-115 for rim and Rene 95 for hub. Dual-alloy fabrication may find applications in automobiles, earth-moving equipment, and energy conversion systems as well as aircraft powerplants. There is potential for such applications as shafts, gears, and blades.

  16. Development of a dual-field heteropoplar power converter

    NASA Technical Reports Server (NTRS)

    Eisenhaure, D. B.; Johnson, B.; Bliamptis, T.; St. George, E.

    1981-01-01

    The design and testing of a 400 watt, dual phase, dual rotor, field modulated inductor alternator is described. The system is designed for use as a flywheel to ac utility line or flywheel to dc bus (electric vehicle) power converter. The machine is unique in that it uses dual rotors and separately controlled fields to produce output current and voltage which are in phase with each other. Having the voltage and current in phase allows the power electronics to be made of simple low cost components. Based on analytical predictions and experimental results, development of a complete 22 kilowatt (30 Hp) power conversion system is recommended. This system would include power electronics and controls and would replace the inductor alternator with an improved electromagnetic conversion system.

  17. Resistivity Measurement by Dual-Configuration Four-Probe Method

    NASA Astrophysics Data System (ADS)

    Yamashita, Masato; Nishii, Toshifumi; Mizutani, Hiroya

    2003-02-01

    The American Society for Testing and Materials (ASTM) Committee has published a new technique for the measurement of resistivity which is termed the dual-configuration four-probe method. The resistivity correction factor is the function of only the data which are obtained from two different electrical configurations of the four probes. The measurement of resistivity and sheet resistance are performed for graphite rectangular plates and indium tin oxide (ITO) films by the conventional four-probe method and the dual-configuration four-probe method. It is demonstrated that the dual-configuration four-probe method which includes a probe array with equal separations of 10 mm can be applied to specimens having thicknesses up to 3.7 mm if a relative resistivity difference up to 5% is allowed.

  18. Dual-color two-photon fluorescence correlation spectroscopy

    NASA Astrophysics Data System (ADS)

    Berland, Keith M.

    2001-04-01

    Fluorescence correlation spectroscopy (FCS) is rapidly growing in popularity as a research tool in biological and biophysical research. Under favorable conditions, FCS measurements can produce an accurate characterization of the chemical, physical, and kinetic properties of a biological system. However, interpretation of FCS data quickly becomes complicated as the heterogeneity of a molecular system increases, as well as when there is significant non-stationery fluorescence background (e.g. intracellular autofluorescence). Use of multi-parameter correlation measurements is one promising approach that can improve the fidelity of FCS measurements in complex systems. In particular, the use of dual-color fluorescence assays, in which different interacting molecular species are labeled with unique fluorescent indicators, can "tune" the sensitivity of FCS measurements in favor of particular molecular species of interest, while simultaneously minimizing the contribution of other molecular species to the overall fluorescence correlation signal. Here we introduce the combined application of two-photon fluorescence excitation and dual-color cross-correlation analysis for detecting molecular interactions in solution. The use of two-photon excitation is particularly advantageous for dual-color FCS applications due to the uncomplicated optical alignment and the superior capabilities for intracellular applications. The theory of two-photon dual-color FCS is introduced, and initial results quantifying hybridization reactions between three independent single stranded DNA molecules are presented.

  19. Dual-Enrollment High-School Graduates' College-Enrollment Considerations

    ERIC Educational Resources Information Center

    Damrow, Roberta J.

    2017-01-01

    This quantitative study examined college enrollment considerations of dual-enrollment students enrolling at one Wisconsin credit-granting technical college. A combined college-choice theoretical framework guided this quantitative study that addressed two research questions: To what extent, if any, did the number of dual credits predict likelihood…

  20. Spatiotemporal Targeting of a Dual-Ligand Nanoparticle to Cancer Metastasis

    PubMed Central

    Doolittle, Elizabeth; Peiris, Pubudu M.; Doron, Gilad; Goldberg, Amy; Tucci, Samantha; Rao, Swetha; Shah, Shruti; Sylvestre, Meilyn; Govender, Priya; Turan, Oguz; Lee, Zhenghong; Schiemann, William P.; Karathanasis, Efstathios

    2015-01-01

    Various targeting strategies and ligands have been employed to direct nanoparticles to tumors that upregulate specific cell-surface molecules. However, tumors display a dynamic, heterogeneous microenvironment, which undergoes spatiotemporal changes including the expression of targetable cell-surface biomarkers. Here, we investigated a dual-ligand nanoparticle to effectively target two receptors overexpressed in aggressive tumors. By using two different chemical specificities, the dual-ligand strategy considered the spatiotemporal alterations in the expression patterns of the receptors in cancer sites. As a case study, we used two mouse models of metastasis of triple-negative breast cancer using the MDA-MB-231 and 4T1 cells. The dual-ligand system utilized two peptides targeting P-selectin and αvβ3 integrin, which are functionally linked to different stages of the development of metastatic disease at a distal site. Using in vivo multimodal imaging and post mortem histological analyses, this study shows that the dual-ligand nanoparticle effectively targeted metastatic disease that was otherwise missed by single-ligand strategies. The dual-ligand nanoparticle was capable of capturing different metastatic sites within the same animal that overexpressed either receptor or both of them. Furthermore, the highly efficient targeting resulted in 22% of the injected dual-ligand nanoparticles being deposited in early-stage metastases within 2 h after injection. PMID:26203676