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Sample records for high-spatial-resolution multi-contrast weighted

  1. The association of lesion eccentricity with plaque morphology and components in the superficial femoral artery: a high-spatial-resolution, multi-contrast weighted CMR study

    Directory of Open Access Journals (Sweden)

    Zhao Xihai

    2010-07-01

    Full Text Available Abstract Background Atherosclerotic plaque morphology and components are predictors of subsequent cardiovascular events. However, associations of plaque eccentricity with plaque morphology and plaque composition are unclear. This study investigated associations of plaque eccentricity with plaque components and morphology in the proximal superficial femoral artery using cardiovascular magnetic resonance (CMR. Methods Twenty-eight subjects with an ankle-brachial index less than 1.00 were examined with 1.5T high-spatial-resolution, multi-contrast weighted CMR. One hundred and eighty diseased locations of the proximal superficial femoral artery (about 40 mm were analyzed. The eccentric lesion was defined as [(Maximum wall thickness- Minimum wall thickness/Maximum wall thickness] ≥ 0.5. The arterial morphology and plaque components were measured using semi-automatic image analysis software. Results One hundred and fifteen locations were identified as eccentric lesions and sixty-five as concentric lesions. The eccentric lesions had larger wall but similar lumen areas, larger mean and maximum wall thicknesses, and more calcification and lipid rich necrotic core, compared to concentric lesions. For lesions with the same lumen area, the degree of eccentricity was associated with an increased wall area. Eccentricity (dichotomous as eccentric or concentric was independently correlated with the prevalence of calcification (odds ratio 3.78, 95% CI 1.47-9.70 after adjustment for atherosclerotic risk factors and wall area. Conclusions Plaque eccentricity is associated with preserved lumen size and advanced plaque features such as larger plaque burden, more lipid content, and increased calcification in the superficial femoral artery.

  2. Accelerated High Spatial Resolution Diffusion-Weighted Imaging.

    Science.gov (United States)

    Scherrer, Benoit; Afacan, Onur; Taquet, Maxime; Prabhu, Sanjay P; Gholipour, Ali; Warfield, Simon K

    2015-01-01

    Acquisition of a series of anisotropically oversampled acquisitions (so-called anisotropic "snapshots") and reconstruction in the image space has recently been proposed to increase the spatial resolution in diffusion weighted imaging (DWI), providing a theoretical 8x acceleration at equal signal-to-noise ratio (SNR) compared to conventional dense k-space sampling. However, in most works, each DW image is reconstructed separately and the fact that the DW images constitute different views of the same anatomy is ignored. In addition, current approaches are limited by their inability to reconstruct a high resolution (HR) acquisition from snapshots with different subsets of diffusion gradients: an isotropic HR gradient image cannot be reconstructed if one .of its anisotropic snapshots is missing, for example due to intra-scan motion, even if other snapshots for this gradient were successfully acquired. In this work, we propose a novel multi-snapshot DWI reconstruction technique that simultaneously achieves HR reconstruction and local tissue model estimation while enabling reconstruction from snapshots containing different subsets of diffusion gradients, providing increased robustness to patient motion and potential for acceleration. Our approach is formalized as a joint probabilistic model with missing observations, from which interactions between missing snapshots, HR reconstruction and a generic tissue model naturally emerge. We evaluate our approach with synthetic simulations, simulated multi-snapshot scenario and in vivo multi-snapshot imaging. We show that (1) our combined approach ultimately provides both better HR reconstruction and better tissue model estimation and (2) the error in the case of missing snapshots can be quantified. Our novel multi-snapshot technique will enable improved high spatial characterization of the brain connectivity and microstructure in vivo.

  3. [Examination of upper abdominal region in high spatial resolution diffusion-weighted imaging using 3-Tesla MRI].

    Science.gov (United States)

    Terada, Masaki; Matsushita, Hiroki; Oosugi, Masanori; Inoue, Kazuyasu; Yaegashi, Taku; Anma, Takeshi

    2009-03-20

    The advantage of the higher signal-to-noise ratio (SNR) of 3-Tesla magnetic resonance imaging (3-Tesla) has the possibility of contributing to the improvement of high spatial resolution without causing image deterioration. In this study, we compared SNR and the apparent diffusion coefficient (ADC) value with 3-Tesla as the condition in the diffusion-weighted image (DWI) parameter of the 1.5-Tesla magnetic resonance imaging (1.5-Tesla) and we examined the high spatial resolution images in the imaging method [respiratory-triggering (RT) method and breath free (BF) method] and artifact (motion and zebra) in the upper abdominal region of DWI at 3-Tesla. We have optimized scan parameters based on phantom and in vivo study. As a result, 3-Tesla was able to obtain about 1.5 times SNR in comparison with the 1.5-Tesla, ADC value had few differences. Moreover, the RT method was effective in correcting the influence of respiratory movement in comparison with the BF method, and image improvement by the effective acquisition of SNR and reduction of the artifact were provided. Thus, DWI of upper abdominal region was a useful sequence for the high spatial resolution in 3-Tesla.

  4. Classification of High Spatial Resolution, Hyperspectral ...

    Science.gov (United States)

    EPA announced the availability of the final report,Classification of High Spatial Resolution, Hyperspectral Remote Sensing Imagery of the Little Miami River Watershed in Southwest Ohio, USA . This report and associated land use/land cover (LULC) coverage is the result of a collaborative effort among an interdisciplinary team of scientists with the U.S. Environmental Protection Agency's (U.S. EPA's) Office of Research and Development in Cincinnati, Ohio. A primary goal of this project is to enhance the use of geography and spatial analytic tools in risk assessment, and to improve the scientific basis for risk management decisions affecting drinking water and water quality. The land use/land cover classification is derived from 82 flight lines of Compact Airborne Spectrographic Imager (CASI) hyperspectral imagery acquired from July 24 through August 9, 2002 via fixed-wing aircraft.

  5. High spatial resolution diffusion tensor imaging and its applications

    CERN Document Server

    Wang, J J

    2002-01-01

    Introduction Magnetic Resonance Imaging is at present the only imaging technique available to measure diffusion of water and metabolites in humans. It provides vital insights to brain connectivity and has proved to be an important tool in diagnosis and therapy planning in many neurological diseases such as brain tumour, ischaemia and multiple sclerosis. This project focuses on the development of a high resolution diffusion tensor imaging technique. In this thesis, the basic theory of diffusion tensor MR Imaging is presented. The technical challenges encountered during development of these techniques will be discussed, with proposed solutions. New sequences with high spatial resolution have been developed and the results are compared with the standard technique more commonly used. Overview The project aims at the development of diffusion tensor imaging techniques with a high spatial resolution. Chapter 2 will describe the basic physics of MRI, the phenomenon of diffusion and the measurement of diffusion by MRI...

  6. A fast high-spatial-resolution Raman distributed temperature sensor

    Science.gov (United States)

    Chen, Y.; Hartog, A. H.; Marsh, R. J.; Hilton, I. M.; Hadley, M. R.; Ross, P. A.

    2014-05-01

    Conventional high-spatial-resolution Raman distributed temperature sensing (DTS) systems are based on photoncounting techniques, which result in slow measurements over short sensing fibers. We describe an alternative approach that uses a high-power, short-pulse-width laser and provides fast measurements over fibers longer than 1 km. We demonstrate measurements with 1-s update times over fiber lengths greater than 1 km with better than 0.4-m spatial resolution. We introduce a figure of merit for DTS and we show a substantial improvement (x 100) over earlier results.

  7. High spatial resolution diffusion tensor imaging and its applications

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jiun-Jie

    2002-07-01

    Introduction Magnetic Resonance Imaging is at present the only imaging technique available to measure diffusion of water and metabolites in humans. It provides vital insights to brain connectivity and has proved to be an important tool in diagnosis and therapy planning in many neurological diseases such as brain tumour, ischaemia and multiple sclerosis. This project focuses on the development of a high resolution diffusion tensor imaging technique. In this thesis, the basic theory of diffusion tensor MR Imaging is presented. The technical challenges encountered during development of these techniques will be discussed, with proposed solutions. New sequences with high spatial resolution have been developed and the results are compared with the standard technique more commonly used. Overview The project aims at the development of diffusion tensor imaging techniques with a high spatial resolution. Chapter 2 will describe the basic physics of MRI, the phenomenon of diffusion and the measurement of diffusion by MRI. The basic parameters used all through the projects will be presented. In Chapter 3, a reproducibility study on DTI with the single shot EPI sequence will be conducted. The single shot DT-EPI was carried out on a stroke patient. In Chapter 4, current techniques on high spatial resolution DTI will be explored. Sequences of Interleaved EPI of two segments and EPI with Half Fourier acquisition will be developed. The sources of artefacts which contaminate most DT images will be discussed with solution proposed. Chapter 5 proposed a new selective averaging algorithm for the data acquired by the sequences of interleaved EPI. It does not require cardiac gating during data acquisition period and thus increase the speed of data collection. A new ghost free segmented EPI sequence will be presented in Chapter 6: Half-FOV EPI. The technique will be tested on a phantom in vitro as well as in two normal male volunteers in vivo. A comparison study on diffusion tensor imaging

  8. High spatial resolution soft-x-ray microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Meyer-Ilse, W.; Medecki, H.; Brown, J.T. [Ernest Orlando Lawrence Berkeley National Lab., CA (United States)] [and others

    1997-04-01

    A new soft x-ray microscope (XM-1) with high spatial resolution has been constructed by the Center for X-ray Optics. It uses bending magnet radiation from beamline 6.1 at the Advanced Light Source, and is used in a variety of projects and applications in the life and physical sciences. Most of these projects are ongoing. The instrument uses zone plate lenses and achieves a resolution of 43 nm, measured over 10% to 90% intensity with a knife edge test sample. X-ray microscopy permits the imaging of relatively thick samples, up to 10 {mu}m thick, in water. XM-1 has an easy to use interface, that utilizes visible light microscopy to precisely position and focus the specimen. The authors describe applications of this device in the biological sciences, as well as in studying industrial applications including structured polymer samples.

  9. Global anthropogenic heat flux database with high spatial resolution

    Science.gov (United States)

    Dong, Y.; Varquez, A. C. G.; Kanda, M.

    2017-02-01

    This study developed a top-down method for estimating global anthropogenic heat emission (AHE), with a high spatial resolution of 30 arc-seconds and temporal resolution of 1 h. Annual average AHE was derived from human metabolic heating and primary energy consumption, which was further divided into three components based on consumer sector. The first and second components were heat loss and heat emissions from industrial sectors equally distributed throughout the country and populated areas, respectively. The third component comprised the sum of emissions from commercial, residential, and transportation sectors (CRT). Bulk AHE from the CRT was proportionally distributed using a global population dataset, with a radiance-calibrated nighttime lights adjustment. An empirical function to estimate monthly fluctuations of AHE based on gridded monthly temperatures was derived from various Japanese and American city measurements. Finally, an AHE database with a global coverage was constructed for the year 2013. Comparisons between our proposed AHE and other existing datasets revealed that the problem of overestimation of AHE intensity in previous top-down models was mitigated by the separation of energy consumption sectors; furthermore, the problem of AHE underestimation at central urban areas was solved by the nighttime lights adjustment. A strong agreement in the monthly profiles of AHE between our database and other bottom-up datasets further proved the validity of the current methodology. Investigations of AHE for the 29 largest urban agglomerations globally highlighted that the share of heat emissions from CRT sectors to the total AHE at the city level was 40-95%; whereas that of metabolic heating varied with the city's level of development by a range of 2-60%. A negative correlation between gross domestic product (GDP) and the share of metabolic heating to a city's total AHE was found. Globally, peak AHE values were found to occur between December and February, while

  10. Strain measurements of a fiber loop rosette using high spatial resolution Rayleigh scatter distributed sensing

    Science.gov (United States)

    Gifford, Dawn K.; Sang, Alex K.; Kreger, Steven T.; Froggatt, Mark E.

    2010-09-01

    Strain is measured with high spatial resolution on fiber loops bonded to a metal test sample to form a fiber rosette. Strain measurements are made using an Optical Backscatter Reflectometer to detect changes in the phase of the Rayleigh Scatter of the fiber with 160 μm spatial resolution along the length of the fiber. Using this experimental set-up, applied strain levels as well as the axis along which the loads are applied are measured. Thermal gradients are also detected. The high spatial resolution and strain sensitivity of this technique enable highly functional fiber rosettes formed of small diameter loops of standard low-bend-loss optical fiber.

  11. High spatial resolution X-ray and gamma ray imaging system using diffraction crystals

    Science.gov (United States)

    Smither, Robert K [Hinsdale, IL

    2011-05-17

    A method and a device for high spatial resolution imaging of a plurality of sources of x-ray and gamma-ray radiation are provided. The device comprises a plurality of arrays, with each array comprising a plurality of elements comprising a first collimator, a diffracting crystal, a second collimator, and a detector.

  12. High spatial resolution three-dimensional mapping of vegetation spectral dynamics using computer vision

    Science.gov (United States)

    Jonathan P. Dandois; Erle C. Ellis

    2013-01-01

    High spatial resolution three-dimensional (3D) measurements of vegetation by remote sensing are advancing ecological research and environmental management. However, substantial economic and logistical costs limit this application, especially for observing phenological dynamics in ecosystem structure and spectral traits. Here we demonstrate a new aerial remote sensing...

  13. High-Temporal-Resolution High-Spatial-Resolution Spaceborne SAR Based on Continuously Varying PRF.

    Science.gov (United States)

    Men, Zhirong; Wang, Pengbo; Li, Chunsheng; Chen, Jie; Liu, Wei; Fang, Yue

    2017-07-25

    Synthetic Aperture Radar (SAR) is a well-established and powerful imaging technique for acquiring high-spatial-resolution images of the Earth's surface. With the development of beam steering techniques, sliding spotlight and staring spotlight modes have been employed to support high-spatial-resolution applications. In addition to this strengthened high-spatial-resolution and wide-swath capability, high-temporal-resolution (short repeat-observation interval) represents a key capability for numerous applications. However, conventional SAR systems are limited in that the same patch can only be illuminated for several seconds within a single pass. This paper considers a novel high-squint-angle system intended to acquire high-spatial-resolution spaceborne SAR images with repeat-observation intervals varying from tens of seconds to several minutes within a single pass. However, an exponentially increased range cell migration would arise and lead to a conflict between the receive window and 'blind ranges'. An efficient data acquisition technique for high-temporal-resolution, high-spatial-resolution and high-squint-angle spaceborne SAR, in which the pulse repetition frequency (PRF) is continuously varied according to the changing slant range, is presented in this paper. This technique allows echo data to remain in the receive window instead of conflicting with the transmitted pulse or nadir echo. Considering the precision of hardware, a compromise and practical strategy is also proposed. Furthermore, a detailed performance analysis of range ambiguities is provided with respect to parameters of TerraSAR-X. For strong point-like targets, the range ambiguity of this technique would be better than that of uniform PRF technique. For this innovative technique, a resampling strategy and modified imaging algorithm have been developed to handle the non-uniformly sampled echo data. Simulations are performed to validate the efficiency of the proposed technique and the associated

  14. Modified ideal observer model (MIOM) for high-contrast and high-spatial resolution CT imaging tasks.

    Science.gov (United States)

    Cruz-Bastida, Juan P; Gomez-Cardona, Daniel; Garrett, John; Szczykutowicz, Timothy; Chen, Guang-Hong; Li, Ke

    2017-09-01

    Although a variety of mathematical observer models have been developed to predict human observer performance for low contrast lesion detection tasks, their predictive power for high contrast and high spatial resolution discrimination imaging tasks, including those in CT bone imaging, could be limited. The purpose of this work was to develop a modified observer model that has improved correlation with human observer performance for these tasks. The proposed observer model, referred to as the modified ideal observer model (MIOM), uses a weight function to penalize components in the task function that have less contribution to the actual human observer performance for high contrast and high spatial resolution discrimination tasks. To validate MIOM, both human observer and observer model studies were performed, each using exactly the same CT imaging task [discrimination of a connected component in a high contrast (1000 HU) high spatial resolution bone fracture model (0.3 mm)] and experimental CT image data. For the human observer studies, three physicist observers rated the connectivity of the fracture model using a five-point Likert scale; for the observer model studies, a total of five observer models, including both conventional models and the proposed MIOM, were used to calculate the discrimination capability of the CT images in resolving the connected component. Images used in the studies encompassed nine different reconstruction kernels. Correlation between human and observer model performance for these kernels were quantified using the Spearman rank correlation coefficient (ρ). After the validation study, an example application of MIOM was presented, in which the observer model was used to select the optimal reconstruction kernel for a High-Resolution (Hi-Res, GE Healthcare) CT scan technique. The performance of the proposed MIOM correlated well with that of the human observers with a Spearman rank correlation coefficient ρ of 0.88 (P = 0.003). In comparison

  15. Prostate Cancer Detection Using High-Spatial Resolution MRI at 7.0 Tesla: Correlation with Histopathologic Findings at Radical Prostatectomy

    Science.gov (United States)

    2013-10-01

    Spatial Resolution MRI at 7.0 Tesla : Correlation with Histopathologic Findings at Radical Prostatectomy PRINCIPAL INVESTIGATOR: Andrew...Cancer Detection Using High-Spatial Resolution MRI at 7.0 Tesla : Correlation with Histopathologic Findings at Radical Prostatectomy 5a. CONTRACT...to achieve standard T2-weighted imaging for 7.0T prostate MRI. Specifically, we implemented a novel surface coil array in conjunction with

  16. Difet: Distributed Feature Extraction Tool for High Spatial Resolution Remote Sensing Images

    Science.gov (United States)

    Eken, S.; Aydın, E.; Sayar, A.

    2017-11-01

    In this paper, we propose distributed feature extraction tool from high spatial resolution remote sensing images. Tool is based on Apache Hadoop framework and Hadoop Image Processing Interface. Two corner detection (Harris and Shi-Tomasi) algorithms and five feature descriptors (SIFT, SURF, FAST, BRIEF, and ORB) are considered. Robustness of the tool in the task of feature extraction from LandSat-8 imageries are evaluated in terms of horizontal scalability.

  17. DIFET: DISTRIBUTED FEATURE EXTRACTION TOOL FOR HIGH SPATIAL RESOLUTION REMOTE SENSING IMAGES

    Directory of Open Access Journals (Sweden)

    S. Eken

    2017-11-01

    Full Text Available In this paper, we propose distributed feature extraction tool from high spatial resolution remote sensing images. Tool is based on Apache Hadoop framework and Hadoop Image Processing Interface. Two corner detection (Harris and Shi-Tomasi algorithms and five feature descriptors (SIFT, SURF, FAST, BRIEF, and ORB are considered. Robustness of the tool in the task of feature extraction from LandSat-8 imageries are evaluated in terms of horizontal scalability.

  18. Visualization of brainstem perfusion using a high spatial resolution SPECT system.

    Science.gov (United States)

    Dierckx, R; Dobbeleir, A; Vandevivere, J; Abts, H; DeDeyn, P P

    1992-05-01

    The authors explored the high spatial resolution of a three-head rotating SPECT system, equipped with lead super-fine fanbeam collimator. The brainstem was high-lighted in a three-dimensional reconstruction, showing perfusion small structures such as mesencephalon, pons, and medulla oblongata. The visualization of brainstem perfusion sets new landmarks in functional neuroimaging and, moreover, was obtained with a commercially available three-head SPECT system.

  19. Development of a compact and high spatial resolution gamma camera system using LaBr 3(Ce)

    Science.gov (United States)

    Yamamoto, Seiichi; Imaizumi, Masao; Shimosegawa, Eku; Hatazawa, Jun

    2010-10-01

    In small animal imaging using a single photon emitting radionuclide, a high spatial resolution gamma camera is required. However, its spatial resolution is limited by the light output of conventional scintillators such as NaI(Tl). We developed and tested a small field-of-view (FOV) gamma camera using a new scintillator, LaBr3(Ce). The LaBr3(Ce) gamma camera consists of a 2 mm thick LaBr3(Ce) scintillator, a 2 in. 8×8 multi-anode position sensitive photomultiplier tube (Hamamatsu H8500), and a personal computer-based data acquisition system. The LaBr3(Ce) scintillator was directly coupled to the PSPMT and was contained in a hermetically shielded and light tight aluminum case. The signals from the PSPMT were gain corrected, weighted summed, and digitized by 100 MHz free running A-D converters in the data acquisition system. The detector part of the gamma camera was encased in a tungsten gamma shield, and a tungsten pinhole collimator was mounted in front of the detector surface. The intrinsic spatial resolution that was measured using a tungsten slit mask was 0.75 mm FWHM, and the energy resolution was 8.9% FWHM for 122 keV gamma photons. We obtained transmission and emission images that demonstrated the high spatial resolution of the gamma camera system. Approximately two years after the fabrication of the detector, the flood image showed significant distortion due to the change in LaBr3(Ce) of its hygroscopic characteristic. These results confirm that the developed LaBr3(Ce) gamma camera is promising for small animal imaging using a low energy single photon emitting radionuclide if the hygroscopic problem of LaBr3(Ce) will be solved.

  20. The fusion of satellite and UAV data: simulation of high spatial resolution band

    Science.gov (United States)

    Jenerowicz, Agnieszka; Siok, Katarzyna; Woroszkiewicz, Malgorzata; Orych, Agata

    2017-10-01

    Remote sensing techniques used in the precision agriculture and farming that apply imagery data obtained with sensors mounted on UAV platforms became more popular in the last few years due to the availability of low- cost UAV platforms and low- cost sensors. Data obtained from low altitudes with low- cost sensors can be characterised by high spatial and radiometric resolution but quite low spectral resolution, therefore the application of imagery data obtained with such technology is quite limited and can be used only for the basic land cover classification. To enrich the spectral resolution of imagery data acquired with low- cost sensors from low altitudes, the authors proposed the fusion of RGB data obtained with UAV platform with multispectral satellite imagery. The fusion is based on the pansharpening process, that aims to integrate the spatial details of the high-resolution panchromatic image with the spectral information of lower resolution multispectral or hyperspectral imagery to obtain multispectral or hyperspectral images with high spatial resolution. The key of pansharpening is to properly estimate the missing spatial details of multispectral images while preserving their spectral properties. In the research, the authors presented the fusion of RGB images (with high spatial resolution) obtained with sensors mounted on low- cost UAV platforms and multispectral satellite imagery with satellite sensors, i.e. Landsat 8 OLI. To perform the fusion of UAV data with satellite imagery, the simulation of the panchromatic bands from RGB data based on the spectral channels linear combination, was conducted. Next, for simulated bands and multispectral satellite images, the Gram-Schmidt pansharpening method was applied. As a result of the fusion, the authors obtained several multispectral images with very high spatial resolution and then analysed the spatial and spectral accuracies of processed images.

  1. Cumulus cloud base height estimation from high spatial resolution Landsat data - A Hough transform approach

    Science.gov (United States)

    Berendes, Todd; Sengupta, Sailes K.; Welch, Ron M.; Wielicki, Bruce A.; Navar, Murgesh

    1992-01-01

    A semiautomated methodology is developed for estimating cumulus cloud base heights on the basis of high spatial resolution Landsat MSS data, using various image-processing techniques to match cloud edges with their corresponding shadow edges. The cloud base height is then estimated by computing the separation distance between the corresponding generalized Hough transform reference points. The differences between the cloud base heights computed by these means and a manual verification technique are of the order of 100 m or less; accuracies of 50-70 m may soon be possible via EOS instruments.

  2. A Method of Spatial Mapping and Reclassification for High-Spatial-Resolution Remote Sensing Image Classification

    Directory of Open Access Journals (Sweden)

    Guizhou Wang

    2013-01-01

    Full Text Available This paper presents a new classification method for high-spatial-resolution remote sensing images based on a strategic mechanism of spatial mapping and reclassification. The proposed method includes four steps. First, the multispectral image is classified by a traditional pixel-based classification method (support vector machine. Second, the panchromatic image is subdivided by watershed segmentation. Third, the pixel-based multispectral image classification result is mapped to the panchromatic segmentation result based on a spatial mapping mechanism and the area dominant principle. During the mapping process, an area proportion threshold is set, and the regional property is defined as unclassified if the maximum area proportion does not surpass the threshold. Finally, unclassified regions are reclassified based on spectral information using the minimum distance to mean algorithm. Experimental results show that the classification method for high-spatial-resolution remote sensing images based on the spatial mapping mechanism and reclassification strategy can make use of both panchromatic and multispectral information, integrate the pixel- and object-based classification methods, and improve classification accuracy.

  3. High-spatial-resolution thermal remote sensing of active volcanic features using Landsat and hyperspectral data

    Science.gov (United States)

    Flynn, Luke P.; Harris, Andrew J. L.; Rothery, David A.; Oppenheimer, Clive

    After the initial observation in 1987 that high spatial resolution data could be used to acquire thermal information for active volcanoes, satellite technology and its applications have leapt forward in possibilities and complexity. Since 1972, the Landsat series of satellites has provided the longest continuous high spatial resolution (Landsat 4 and 5 (launched in 1982 and 1984, respectively) featuring the Thematic Mapper system have made it possible to detect, map, and model high temperature features such as lava bodies and fires. Landsat 7 was launched in April, 1999, carrying an enhanced instrument package that includes a higher spatial resolution thermal band and a 15-m panchromatic band that will greatly aid detailed mapping of volcanic features. Current planning for the future Landsat 8 instrument includes a fundamental shift towards a lighter, more energy efficient instrument having a greater number of spectral bands. Hyperspectral sensors, such as that of Earth Orbiter-1, that have been planned for launch as part of the New Millennium Program, are being considered as Landsat 8 prototypes. Initial studies of lava flows and lava lakes using field spectrometers afford a glimpse of the capabilities offered by the next generation of satellites to model lava flow temperatures. Hyperspectral measurements of lava flows allow for the solution of numerous thermal components, which can then be used for much more detailed modeling than can be supported by broad band radiometry.

  4. Evaluating the Value of High Spatial Resolution in National Capacity Expansion Models using ReEDS

    Energy Technology Data Exchange (ETDEWEB)

    Krishnan, Venkat; Cole, Wesley

    2016-07-18

    This poster is based on the paper of the same name, presented at the IEEE Power & Energy Society General Meeting, July18, 2016. Power sector capacity expansion models (CEMs) have a broad range of spatial resolutions. This paper uses the Regional Energy Deployment System (ReEDS) model, a long-term national scale electric sector CEM, to evaluate the value of high spatial resolution for CEMs. ReEDS models the United States with 134 load balancing areas (BAs) and captures the variability in existing generation parameters, future technology costs, performance, and resource availability using very high spatial resolution data, especially for wind and solar modeled at 356 resource regions. In this paper we perform planning studies at three different spatial resolutions - native resolution (134 BAs), state-level, and NERC region level - and evaluate how results change under different levels of spatial aggregation in terms of renewable capacity deployment and location, associated transmission builds, and system costs. The results are used to ascertain the value of high geographically resolved models in terms of their impact on relative competitiveness among renewable energy resources.

  5. A Method of Spatial Mapping and Reclassification for High-Spatial-Resolution Remote Sensing Image Classification

    Science.gov (United States)

    Wang, Guizhou; Liu, Jianbo; He, Guojin

    2013-01-01

    This paper presents a new classification method for high-spatial-resolution remote sensing images based on a strategic mechanism of spatial mapping and reclassification. The proposed method includes four steps. First, the multispectral image is classified by a traditional pixel-based classification method (support vector machine). Second, the panchromatic image is subdivided by watershed segmentation. Third, the pixel-based multispectral image classification result is mapped to the panchromatic segmentation result based on a spatial mapping mechanism and the area dominant principle. During the mapping process, an area proportion threshold is set, and the regional property is defined as unclassified if the maximum area proportion does not surpass the threshold. Finally, unclassified regions are reclassified based on spectral information using the minimum distance to mean algorithm. Experimental results show that the classification method for high-spatial-resolution remote sensing images based on the spatial mapping mechanism and reclassification strategy can make use of both panchromatic and multispectral information, integrate the pixel- and object-based classification methods, and improve classification accuracy. PMID:24453808

  6. Frequency-comb-based BOTDA sensors for high-spatial-resolution/long-distance sensing.

    Science.gov (United States)

    Jia, Xin-Hong; Chang, Han-Qing; Lin, Kai; Xu, Cong; Wu, Jia-Gui

    2017-03-20

    Frequency-comb-based Brillouin optical time-domain analysis (BOTDA) sensors were developed to achieve acquisition-time reduction and high-spatial-resolution/long-distance sensing simultaneously. We found that, for the standard frequency-comb-based BOTDA, the use of a double-sideband (DSB) pulse generates a series of pulse pairs that simultaneously propagate along the sensing fiber, leading to a nonlinear interaction between the two sidebands of each frequency comb pulse, and a significant splitting of the Brillouin gain spectrum (BGS). This problem prevents its application in high-spatial-resolution sensing due to the higher pulse power requirement. Thus, one of the sidebands of DSB pulse was proposed for greatly suppressing the BGS distortion. In combination with the phonon pre-excitation technique based on phase-shifted pulse, a sensor with a spatial-resolution approximately 60 cm along a fiber approximately 592 m in length was demonstrated. Furthermore, we explored the detailed performance of long-distance sensing by frequency- comb-based BOTDA. The use of a frequency comb for the probe wave can suppress the pulse distortion and non-local effect, which is helpful for extending the sensing distance. A spatial resolution of approximately 6 m along a sensing fiber approximately 74.2 km in length was successfully demonstrated.

  7. High spatial resolution brain functional MRI using submillimeter balanced steady-state free precession acquisition

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Pei-Hsin; Chung, Hsiao-Wen [Department of Electrical Engineering, National Taiwan University, Taipei 10617, Taiwan (China); Tsai, Ping-Huei [Imaging Research Center, Taipei Medical University, Taipei 11031, Taiwan and Department of Medical Imaging, Taipei Medical University Hospital, Taipei Medical University, Taipei 11031, Taiwan (China); Wu, Ming-Long, E-mail: minglong.wu@csie.ncku.edu.tw [Institute of Medical Informatics, National Cheng-Kung University, Tainan 70101, Taiwan and Department of Computer Science and Information Engineering, National Cheng-Kung University, Tainan 70101, Taiwan (China); Chuang, Tzu-Chao [Department of Electrical Engineering, National Sun Yat-Sen University, Kaohsiung 80424, Taiwan (China); Shih, Yi-Yu [Siemens Limited Healthcare Sector, Taipei 11503, Taiwan (China); Huang, Teng-Yi [Department of Electrical Engineering, National Taiwan University of Science and Technology, Taipei 10607, Taiwan (China)

    2013-12-15

    Purpose: One of the technical advantages of functional magnetic resonance imaging (fMRI) is its precise localization of changes from neuronal activities. While current practice of fMRI acquisition at voxel size around 3 × 3 × 3 mm{sup 3} achieves satisfactory results in studies of basic brain functions, higher spatial resolution is required in order to resolve finer cortical structures. This study investigated spatial resolution effects on brain fMRI experiments using balanced steady-state free precession (bSSFP) imaging with 0.37 mm{sup 3} voxel volume at 3.0 T. Methods: In fMRI experiments, full and unilateral visual field 5 Hz flashing checkerboard stimulations were given to healthy subjects. The bSSFP imaging experiments were performed at three different frequency offsets to widen the coverage, with functional activations in the primary visual cortex analyzed using the general linear model. Variations of the spatial resolution were achieved by removing outerk-space data components. Results: Results show that a reduction in voxel volume from 3.44 × 3.44 × 2 mm{sup 3} to 0.43 × 0.43 × 2 mm{sup 3} has resulted in an increase of the functional activation signals from (7.7 ± 1.7)% to (20.9 ± 2.0)% at 3.0 T, despite of the threefold SNR decreases in the original images, leading to nearly invariant functional contrast-to-noise ratios (fCNR) even at high spatial resolution. Activation signals aligning nicely with gray matter sulci at high spatial resolution would, on the other hand, have possibly been mistaken as noise at low spatial resolution. Conclusions: It is concluded that the bSSFP sequence is a plausible technique for fMRI investigations at submillimeter voxel widths without compromising fCNR. The reduction of partial volume averaging with nonactivated brain tissues to retain fCNR is uniquely suitable for high spatial resolution applications such as the resolving of columnar organization in the brain.

  8. Spatiotemporal neurodynamics underlying internally and externally driven temporal prediction: a high spatial resolution ERP study.

    Science.gov (United States)

    Mento, Giovanni; Tarantino, Vincenza; Vallesi, Antonino; Bisiacchi, Patrizia Silvia

    2015-03-01

    Temporal prediction (TP) is a flexible and dynamic cognitive ability. Depending on the internal or external nature of information exploited to generate TP, distinct cognitive and brain mechanisms are engaged with the same final goal of reducing uncertainty about the future. In this study, we investigated the specific brain mechanisms involved in internally and externally driven TP. To this end, we employed an experimental paradigm purposely designed to elicit and compare externally and internally driven TP and a combined approach based on the application of a distributed source reconstruction modeling on a high spatial resolution electrophysiological data array. Specific spatiotemporal ERP signatures were identified, with significant modulation of contingent negative variation and frontal late sustained positivity in external and internal TP contexts, respectively. These different electrophysiological patterns were supported by the engagement of distinct neural networks, including a left sensorimotor and a prefrontal circuit for externally and internally driven TP, respectively.

  9. High spatial resolution phase-sensitive optical time domain reflectometer with a frequency-swept pulse.

    Science.gov (United States)

    Lu, Bin; Pan, Zhengqing; Wang, Zhaoyong; Zheng, Hanrong; Ye, Qing; Qu, Ronghui; Cai, Haiwen

    2017-02-01

    A high spatial resolution phase-sensitive optical time domain reflectometer (ϕ-OTDR) with an optical frequency-swept pulse (FSP) is proposed, and the experimental results are presented in the Letter. The FSP ϕ-OTDR uses optical pulses with linear frequency modulation with higher pulse energy for longer sensing fiber and uses matched filter in the receiver to compress the processed pulse width. Thus, the contradiction between spatial resolution and the working distance in ordinary ϕ-OTDR is relaxed. A spatial resolution of 30 cm, a sensing distance of 19.8 km, and a signal-to-noise ratio of 10 dB for vibration sensing were obtained experimentally. To our best of our knowledge, this is the first time that a sub-meter spatial resolution over such a long sensing range has been reported in ϕ-OTDR sensors.

  10. Estimating babassu palm density using automatic palm tree detection with very high spatial resolution satellite images.

    Science.gov (United States)

    Dos Santos, Alessio Moreira; Mitja, Danielle; Delaître, Eric; Demagistri, Laurent; de Souza Miranda, Izildinha; Libourel, Thérèse; Petit, Michel

    2017-05-15

    High spatial resolution images as well as image processing and object detection algorithms are recent technologies that aid the study of biodiversity and commercial plantations of forest species. This paper seeks to contribute knowledge regarding the use of these technologies by studying randomly dispersed native palm tree. Here, we analyze the automatic detection of large circular crown (LCC) palm tree using a high spatial resolution panchromatic GeoEye image (0.50 m) taken on the area of a community of small agricultural farms in the Brazilian Amazon. We also propose auxiliary methods to estimate the density of the LCC palm tree Attalea speciosa (babassu) based on the detection results. We used the "Compt-palm" algorithm based on the detection of palm tree shadows in open areas via mathematical morphology techniques and the spatial information was validated using field methods (i.e. structural census and georeferencing). The algorithm recognized individuals in life stages 5 and 6, and the extraction percentage, branching factor and quality percentage factors were used to evaluate its performance. A principal components analysis showed that the structure of the studied species differs from other species. Approximately 96% of the babassu individuals in stage 6 were detected. These individuals had significantly smaller stipes than the undetected ones. In turn, 60% of the stage 5 babassu individuals were detected, showing significantly a different total height and a different number of leaves from the undetected ones. Our calculations regarding resource availability indicate that 6870 ha contained 25,015 adult babassu palm tree, with an annual potential productivity of 27.4 t of almond oil. The detection of LCC palm tree and the implementation of auxiliary field methods to estimate babassu density is an important first step to monitor this industry resource that is extremely important to the Brazilian economy and thousands of families over a large scale. Copyright

  11. Estimation of the high-spatial-resolution variability in extreme wind speeds for forestry applications

    Science.gov (United States)

    Venäläinen, Ari; Laapas, Mikko; Pirinen, Pentti; Horttanainen, Matti; Hyvönen, Reijo; Lehtonen, Ilari; Junila, Päivi; Hou, Meiting; Peltola, Heli M.

    2017-07-01

    The bioeconomy has an increasing role to play in climate change mitigation and the sustainable development of national economies. In Finland, a forested country, over 50 % of the current bioeconomy relies on the sustainable management and utilization of forest resources. Wind storms are a major risk that forests are exposed to and high-spatial-resolution analysis of the most vulnerable locations can produce risk assessment of forest management planning. In this paper, we examine the feasibility of the wind multiplier approach for downscaling of maximum wind speed, using 20 m spatial resolution CORINE land-use dataset and high-resolution digital elevation data. A coarse spatial resolution estimate of the 10-year return level of maximum wind speed was obtained from the ERA-Interim reanalyzed data. Using a geospatial re-mapping technique the data were downscaled to 26 meteorological station locations to represent very diverse environments. Applying a comparison, we find that the downscaled 10-year return levels represent 66 % of the observed variation among the stations examined. In addition, the spatial variation in wind-multiplier-downscaled 10-year return level wind was compared with the WAsP model-simulated wind. The heterogeneous test area was situated in northern Finland, and it was found that the major features of the spatial variation were similar, but in some locations, there were relatively large differences. The results indicate that the wind multiplier method offers a pragmatic and computationally feasible tool for identifying at a high spatial resolution those locations with the highest forest wind damage risks. It can also be used to provide the necessary wind climate information for wind damage risk model calculations, thus making it possible to estimate the probability of predicted threshold wind speeds for wind damage and consequently the probability (and amount) of wind damage for certain forest stand configurations.

  12. Estimation of the high-spatial-resolution variability in extreme wind speeds for forestry applications

    Directory of Open Access Journals (Sweden)

    A. Venäläinen

    2017-07-01

    Full Text Available The bioeconomy has an increasing role to play in climate change mitigation and the sustainable development of national economies. In Finland, a forested country, over 50 % of the current bioeconomy relies on the sustainable management and utilization of forest resources. Wind storms are a major risk that forests are exposed to and high-spatial-resolution analysis of the most vulnerable locations can produce risk assessment of forest management planning. In this paper, we examine the feasibility of the wind multiplier approach for downscaling of maximum wind speed, using 20 m spatial resolution CORINE land-use dataset and high-resolution digital elevation data. A coarse spatial resolution estimate of the 10-year return level of maximum wind speed was obtained from the ERA-Interim reanalyzed data. Using a geospatial re-mapping technique the data were downscaled to 26 meteorological station locations to represent very diverse environments. Applying a comparison, we find that the downscaled 10-year return levels represent 66 % of the observed variation among the stations examined. In addition, the spatial variation in wind-multiplier-downscaled 10-year return level wind was compared with the WAsP model-simulated wind. The heterogeneous test area was situated in northern Finland, and it was found that the major features of the spatial variation were similar, but in some locations, there were relatively large differences. The results indicate that the wind multiplier method offers a pragmatic and computationally feasible tool for identifying at a high spatial resolution those locations with the highest forest wind damage risks. It can also be used to provide the necessary wind climate information for wind damage risk model calculations, thus making it possible to estimate the probability of predicted threshold wind speeds for wind damage and consequently the probability (and amount of wind damage for certain forest stand configurations.

  13. Modelling malaria risk in East Africa at high-spatial resolution.

    Science.gov (United States)

    Omumbo, J A; Hay, S I; Snow, R W; Tatem, A J; Rogers, D J

    2005-06-01

    Malaria risk maps have re-emerged as an important tool for appropriately targeting the limited resources available for malaria control. In Sub-Saharan Africa empirically derived maps using standardized criteria are few and this paper considers the development of a model of malaria risk for East Africa. Statistical techniques were applied to high spatial resolution remotely sensed, human settlement and land-use data to predict the intensity of malaria transmission as defined according to the childhood parasite ratio (PR) in East Africa. Discriminant analysis was used to train environmental and human settlement predictor variables to distinguish between four classes of PR risk shown to relate to disease outcomes in the region. Independent empirical estimates of the PR were identified from Kenya, Tanzania and Uganda (n = 330). Surrogate markers of climate recorded on-board earth orbiting satellites, population settlement, elevation and water bodies all contributed significantly to the predictive models of malaria transmission intensity in the sub-region. The accuracy of the model was increased by stratifying East Africa into two ecological zones. In addition, the inclusion of urbanization as a predictor of malaria prevalence, whilst reducing formal accuracy statistics, nevertheless improved the consistency of the predictive map with expert opinion malaria maps. The overall accuracy achieved with ecological zone and urban stratification was 62% with surrogates of precipitation and temperature being among the most discriminating predictors of the PR. It is possible to achieve a high degree of predictive accuracy for Plasmodium falciparum parasite prevalence in East Africa using high-spatial resolution environmental data. However, discrepancies were evident from mapped outputs from the models which were largely due to poor coverage of malaria training data and the comparable spatial resolution of predictor data. These deficiencies will only be addressed by more random

  14. Geostatistical uncertainty of assessing air quality using high-spatial-resolution lichen data: A health study in the urban area of Sines, Portugal.

    Science.gov (United States)

    Ribeiro, Manuel C; Pinho, P; Branquinho, C; Llop, Esteve; Pereira, Maria J

    2016-08-15

    In most studies correlating health outcomes with air pollution, personal exposure assignments are based on measurements collected at air-quality monitoring stations not coinciding with health data locations. In such cases, interpolators are needed to predict air quality in unsampled locations and to assign personal exposures. Moreover, a measure of the spatial uncertainty of exposures should be incorporated, especially in urban areas where concentrations vary at short distances due to changes in land use and pollution intensity. These studies are limited by the lack of literature comparing exposure uncertainty derived from distinct spatial interpolators. Here, we addressed these issues with two interpolation methods: regression Kriging (RK) and ordinary Kriging (OK). These methods were used to generate air-quality simulations with a geostatistical algorithm. For each method, the geostatistical uncertainty was drawn from generalized linear model (GLM) analysis. We analyzed the association between air quality and birth weight. Personal health data (n=227) and exposure data were collected in Sines (Portugal) during 2007-2010. Because air-quality monitoring stations in the city do not offer high-spatial-resolution measurements (n=1), we used lichen data as an ecological indicator of air quality (n=83). We found no significant difference in the fit of GLMs with any of the geostatistical methods. With RK, however, the models tended to fit better more often and worse less often. Moreover, the geostatistical uncertainty results showed a marginally higher mean and precision with RK. Combined with lichen data and land-use data of high spatial resolution, RK is a more effective geostatistical method for relating health outcomes with air quality in urban areas. This is particularly important in small cities, which generally do not have expensive air-quality monitoring stations with high spatial resolution. Further, alternative ways of linking human activities with their

  15. Quantifying tree mortality in a mixed species woodland using multitemporal high spatial resolution satellite imagery

    Science.gov (United States)

    Garrity, Steven R.; Allen, Craig D.; Brumby, Steven P.; Gangodagamage, Chandana; McDowell, Nate G.; Cai, D. Michael

    2013-01-01

    Widespread tree mortality events have recently been observed in several biomes. To effectively quantify the severity and extent of these events, tools that allow for rapid assessment at the landscape scale are required. Past studies using high spatial resolution satellite imagery have primarily focused on detecting green, red, and gray tree canopies during and shortly after tree damage or mortality has occurred. However, detecting trees in various stages of death is not always possible due to limited availability of archived satellite imagery. Here we assess the capability of high spatial resolution satellite imagery for tree mortality detection in a southwestern U.S. mixed species woodland using archived satellite images acquired prior to mortality and well after dead trees had dropped their leaves. We developed a multistep classification approach that uses: supervised masking of non-tree image elements; bi-temporal (pre- and post-mortality) differencing of normalized difference vegetation index (NDVI) and red:green ratio (RGI); and unsupervised multivariate clustering of pixels into live and dead tree classes using a Gaussian mixture model. Classification accuracies were improved in a final step by tuning the rules of pixel classification using the posterior probabilities of class membership obtained from the Gaussian mixture model. Classifications were produced for two images acquired post-mortality with overall accuracies of 97.9% and 98.5%, respectively. Classified images were combined with land cover data to characterize the spatiotemporal characteristics of tree mortality across areas with differences in tree species composition. We found that 38% of tree crown area was lost during the drought period between 2002 and 2006. The majority of tree mortality during this period was concentrated in piñon-juniper (Pinus edulis-Juniperus monosperma) woodlands. An additional 20% of the tree canopy died or was removed between 2006 and 2011, primarily in areas

  16. High Spatial Resolution Airborne Multispectral Thermal Infrared Remote Sensing Data for Analysis of Urban Landscape Characteristics

    Science.gov (United States)

    Quattrochi, Dale A.; Luvall, Jeffrey C.; Estes, Maurice G., Jr.; Arnold, James E. (Technical Monitor)

    2000-01-01

    We have used airborne multispectral thermal infrared (TIR) remote sensing data collected at a high spatial resolution (i.e., 10m) over several cities in the United States to study thermal energy characteristics of the urban landscape. These TIR data provide a unique opportunity to quantify thermal responses from discrete surfaces typical of the urban landscape and to identify both the spatial arrangement and patterns of thermal processes across the city. The information obtained from these data is critical to understanding how urban surfaces drive or force development of the Urban Heat Island (UHI) effect, which exists as a dome of elevated air temperatures that presides over cities in contrast to surrounding non-urbanized areas. The UHI is most pronounced in the summertime where urban surfaces, such as rooftops and pavement, store solar radiation throughout the day, and release this stored energy slowly after sunset creating air temperatures over the city that are in excess of 2-4'C warmer in contrast with non-urban or rural air temperatures. The UHI can also exist as a daytime phenomenon with surface temperatures in downtown areas of cities exceeding 38'C. The implications of the UHI are significant, particularly as an additive source of thermal energy input that exacerbates the overall production of ground level ozone over cities. We have used the Airborne Thermal and Land Applications Sensor (ATLAS), flown onboard a Lear 23 jet aircraft from the NASA Stennis Space Center, to acquire high spatial resolution multispectral TIR data (i.e., 6 bandwidths between 8.2-12.2 (um) over Huntsville, Alabama, Atlanta, Georgia, Baton Rouge, Louisiana, Salt Lake City, Utah, and Sacramento, California. These TIR data have been used to produce maps and other products, showing the spatial distribution of heating and cooling patterns over these cities to better understand how the morphology of the urban landscape affects development of the UHI. In turn, these data have been used

  17. In vivo functional connectome of human brainstem nuclei of the ascending arousal, autonomic, and motor systems by high spatial resolution 7-Tesla fMRI.

    Science.gov (United States)

    Bianciardi, Marta; Toschi, Nicola; Eichner, Cornelius; Polimeni, Jonathan R; Setsompop, Kawin; Brown, Emery N; Hämäläinen, Matti S; Rosen, Bruce R; Wald, Lawrence L

    2016-06-01

    Our aim was to map the in vivo human functional connectivity of several brainstem nuclei with the rest of the brain by using seed-based correlation of ultra-high magnetic field functional magnetic resonance imaging (fMRI) data. We used the recently developed template of 11 brainstem nuclei derived from multi-contrast structural MRI at 7 Tesla as seed regions to determine their connectivity to the rest of the brain. To achieve this, we used the increased contrast-to-noise ratio of 7-Tesla fMRI compared with 3 Tesla and time-efficient simultaneous multi-slice imaging to cover the brain with high spatial resolution (1.1-mm isotropic nominal resolution) while maintaining a short repetition time (2.5 s). The delineated Pearson's correlation-based functional connectivity diagrams (connectomes) of 11 brainstem nuclei of the ascending arousal, motor, and autonomic systems from 12 controls are presented and discussed in the context of existing histology and animal work. Considering that the investigated brainstem nuclei play a crucial role in several vital functions, the delineated preliminary connectomes might prove useful for future in vivo research and clinical studies of human brainstem function and pathology, including disorders of consciousness, sleep disorders, autonomic disorders, Parkinson's disease, and other motor disorders.

  18. High Spatial Resolution MRI of Cystic Adventitial Disease of the Iliofemoral Vein Communicating with the Hip Joint

    Energy Technology Data Exchange (ETDEWEB)

    Michaelides, Michael, E-mail: mihalismihailidis@gmail.com [Ygia Polyclinic Hospital, MRI/CT Department (Cyprus); Papas, Stylianos, E-mail: vascular@drpapas.com [Ygia Polyclinic Hospital, Vascular Surgery Department (Cyprus); Pantziara, Maria, E-mail: mgpantziara@gmail.com; Ioannidis, Kleanthis, E-mail: aktinodiagnostis@gmail.com [Ygia Polyclinic Hospital, MRI/CT Department (Cyprus)

    2013-05-14

    Venous cystic adventitial disease (CAD) is an extremely rare entity, and so far less than 20 cases have been described in the literature. Herein, we describe the imaging findings of CAD of iliofemoral vein in a 51-year-old woman who presented with leg swelling with special emphasis on high spatial resolution MRI, which demonstrated communication of the cyst with the hip joint. To our knowledge, this is the first description of high spatial resolution MRI findings in venous CAD supporting a new theory about the pathogenesis of venous CAD.

  19. High spatial resolution MRI of cystic adventitial disease of the iliofemoral vein communicating with the hip joint.

    Science.gov (United States)

    Michaelides, Michael; Papas, Stylianos; Pantziara, Maria; Ioannidis, Kleanthis

    2014-02-01

    Venous cystic adventitial disease (CAD) is an extremely rare entity, and so far less than 20 cases have been described in the literature. Herein, we describe the imaging findings of CAD of iliofemoral vein in a 51-year-old woman who presented with leg swelling with special emphasis on high spatial resolution MRI, which demonstrated communication of the cyst with the hip joint. To our knowledge, this is the first description of high spatial resolution MRI findings in venous CAD supporting a new theory about the pathogenesis of venous CAD.

  20. Large patch convolutional neural networks for the scene classification of high spatial resolution imagery

    Science.gov (United States)

    Zhong, Yanfei; Fei, Feng; Zhang, Liangpei

    2016-04-01

    The increase of the spatial resolution of remote-sensing sensors helps to capture the abundant details related to the semantics of surface objects. However, it is difficult for the popular object-oriented classification approaches to acquire higher level semantics from the high spatial resolution remote-sensing (HSR-RS) images, which is often referred to as the "semantic gap." Instead of designing sophisticated operators, convolutional neural networks (CNNs), a typical deep learning method, can automatically discover intrinsic feature descriptors from a large number of input images to bridge the semantic gap. Due to the small data volume of the available HSR-RS scene datasets, which is far away from that of the natural scene datasets, there have been few reports of CNN approaches for HSR-RS image scene classifications. We propose a practical CNN architecture for HSR-RS scene classification, named the large patch convolutional neural network (LPCNN). The large patch sampling is used to generate hundreds of possible scene patches for the feature learning, and a global average pooling layer is used to replace the fully connected network as the classifier, which can greatly reduce the total parameters. The experiments confirm that the proposed LPCNN can learn effective local features to form an effective representation for different land-use scenes, and can achieve a performance that is comparable to the state-of-the-art on public HSR-RS scene datasets.

  1. Mapping Banana Plants from High Spatial Resolution Orthophotos to Facilitate Plant Health Assessment

    Directory of Open Access Journals (Sweden)

    Kasper Johansen

    2014-09-01

    Full Text Available The Banana Bunchy Top Virus (Genus: Babuvirus reduces plant growth and prevents banana production. Because of the very large number of properties with banana plants in South East Queensland, Australia, a mapping approach was developed to delineate individual and clusters of banana plants to help plant identification and enable prioritization of plant inspections for Banana Bunchy Top Virus. Due to current outbreaks in South East Queensland, there are concerns that the virus may spread to the major banana growing districts further north. The mapping approach developed was based on very high spatial resolution airborne orthophotos. Object-based image analysis was used to: (1 detect banana plants using edge and line detection approaches; (2 produce accurate and realistic outlines around classified banana plants; and (3 evaluate the mapping results. The mapping approach was developed based on 10 image tiles of 1 km × 1 km and was applied to orthophotos (3600 image tiles from September 2011 covering the entire Sunshine Coast Region in South East Queensland. Based on field inspections of the classified maps, a user’s mapping accuracy of 88% (n = 146 was achieved. The results will facilitate the detection of banana plants and increase the inspection rate of Banana Bunchy Top Virus in the future.

  2. Femtosecond laser-induced breakdown spectroscopy: Elemental imaging of thin films with high spatial resolution

    Science.gov (United States)

    Ahamer, Christoph M.; Riepl, Kevin M.; Huber, Norbert; Pedarnig, Johannes D.

    2017-10-01

    We investigate femtosecond laser-induced breakdown spectroscopy (fs-LIBS) for the spectrochemical imaging of thin films with high spatial resolution. Chemical images are obtained by recording LIBS spectra at each site of 2D raster-scans across the samples employing one fs-laser pulse per site. The diffraction images of the Echelle spectrometer are binned to reduce the read-out time of the intensified CCD detector and to increase the stability of the emission signals against peak drifts in the echellograms. For copper thin films on glass the intensities of Cu I emission lines and the size of ablation craters vary non-monotonously with the film thickness hCu = 5-500 nm. The emission efficiency, defined as the Cu I line intensity per ablated volume, strongly decreases for films thicker than the optical penetration depth. The Na I line intensity from glass increases exponentially with decreasing Cu film thickness. For yttrium barium copper oxide (YBCO) thin films on MgO various atomic and molecular emission lines of the laser-induced plasma are measured (film thickness hYBCO = 200-1000 nm). The obtained element (Y, Ba, Cu, Mg) and molecular (Y-O) fs-LIBS images match the structure of the micro-patterned YBCO films very well. The achieved lateral resolution δr = 6 μm is among the best values reported for spectrochemical LIBS imaging.

  3. The Fisher Kernel Coding Framework for High Spatial Resolution Scene Classification

    Directory of Open Access Journals (Sweden)

    Bei Zhao

    2016-02-01

    Full Text Available High spatial resolution (HSR image scene classification is aimed at bridging the semantic gap between low-level features and high-level semantic concepts, which is a challenging task due to the complex distribution of ground objects in HSR images. Scene classification based on the bag-of-visual-words (BOVW model is one of the most successful ways to acquire the high-level semantic concepts. However, the BOVW model assigns local low-level features to their closest visual words in the “visual vocabulary” (the codebook obtained by k-means clustering, which discards too many useful details of the low-level features in HSR images. In this paper, a feature coding method under the Fisher kernel (FK coding framework is introduced to extend the BOVW model by characterizing the low-level features with a gradient vector instead of the count statistics in the BOVW model, which results in a significant decrease in the codebook size and an acceleration of the codebook learning process. By considering the differences in the distributions of the ground objects in different regions of the images, local FK (LFK is proposed for the HSR image scene classification method. The experimental results show that the proposed scene classification methods under the FK coding framework can greatly reduce the computational cost, and can obtain a better scene classification accuracy than the methods based on the traditional BOVW model.

  4. 3D printing of hydrogels in a temperature controlled environment with high spatial resolution

    Directory of Open Access Journals (Sweden)

    Fischer Benjamin

    2016-09-01

    Full Text Available There is great hope in 3D printing techniques to create patient specific scaffolds for therapeutic applications. The majority of these approaches rely on materials that both give support to cells and effectively mimic a tissue specific microenvironment. Hydrogels provide an exceptional support for cells but their physicochemical properties are not suited for conventional additive layer manufacturing. Their low viscosity and resulting fluidic nature inhibit voluminous 3D deposition and lead to crude printing accuracy. To enhance mechanical features, hydrogels are often chemically modified and/or mixed with additives; however it is not clear whether these changes induce effects on cellular behavior or if in vivo applications are at risk. Certainly it increases the complexity of scaffold systems. To circumvent these obstacles, we aimed for a 3D printing technique which is capable of creating scaffolds out of unmodified, pure hydrogels. Here we present a new method to produce alginate scaffolds in a viscosity- independent manner with high spatial resolution. This is achieved by printing in a sub-zero environment which leads to fast freezing of the hydrogels, thus preserving the printed shape and circumventing any viscosity dependent flows. This enables the user to create scaffolds which are able to reflect soft or stiff cell niches.

  5. Monitoring habitat preserves in southern California using high spatial resolution multispectral imagery.

    Science.gov (United States)

    Coulter, Lloyd L; Stow, Douglas A

    2009-05-01

    Habitat preserve systems have been established adjacent to the densely populated regions of southern California to support indigenous plant and animal species that are listed as rare, threatened, or endangered. Monitoring the condition of habitat across these broad preserves is necessary to ensure their long-term viability and may be effectively accomplished using remote sensing techniques with high spatial resolution visible and near-infrared (VNIR) multispectral imagery. The utility of 1 m spatial resolution VNIR imagery for detailed change detection and monitoring of Mediterranean-type ecosystems is assessed here. Image acquisition and preprocessing procedures were conducted to ensure that image-detected changes represented real changes and not artifacts. Change classification products with six spectral-based transition classes were generated using multiband image differencing (MID) for three change periods: 1998-1999, 1998-2001, and 1998-2005. Land cover changes relevant to habitat quality monitoring such as human-induced disturbance, fire, vegetation growth/recovery, and drought related vegetation stress were readily detected using the multitemporal VNIR imagery. Suggestions for operational habitat monitoring using image products and mobile geographic information system technologies are provided.

  6. Matrix sublimation/recrystallization for imaging proteins by mass spectrometry at high spatial resolution.

    Science.gov (United States)

    Yang, Junhai; Caprioli, Richard M

    2011-07-15

    We have employed matrix deposition by sublimation for protein image analysis on tissue sections using a hydration/recrystallization process that produces high-quality MALDI mass spectra and high-spatial-resolution ion images. We systematically investigated different washing protocols, the effect of tissue section thickness, the amount of sublimated matrix per unit area, and different recrystallization conditions. The results show that an organic solvent rinse followed by ethanol/water rinses substantially increased sensitivity for the detection of proteins. Both the thickness of the tissue section and the amount of sinapinic acid sublimated per unit area have optimal ranges for maximal protein signal intensity. Ion images of mouse and rat brain sections at 50, 20, and 10 μm spatial resolution are presented and are correlated with hematoxylin and eosin (H&E)-stained optical images. For targeted analysis, histology-directed imaging can be performed using this protocol where MS analysis and H&E staining are performed on the same section.

  7. A high spatial resolution double-pulse Thomson scattering diagnostic; description, assessment of accuracy and examples of applications

    NARCIS (Netherlands)

    Beurskens, M. N. A.; Barth, C. J.; Cardozo, N. J. L.; van der Meiden, H. J.

    1999-01-01

    A high spatial resolution (3 mm full width half maximum, i.e. 2% of the minor radius) double-pulse multiposition Thomson scattering system was in operation at the Rijnhuizen tokamak project RTP from March 1996 until September 1998. It upgrades the previously installed single-pulse Thomson scattering

  8. An optical setup for electric field measurements in MRI with high spatial resolution

    Science.gov (United States)

    Reiss, Simon; Bitzer, Andreas; Bock, Michael

    2015-06-01

    Electric field measurements in the magnetic resonance (MR) imaging environment are important to assess potentially dangerous radio-frequency (RF) heating in the vicinity of metallic structures such as coils, implants or catheters. So far, E-field measurements have been performed with dipole antennas that lag of limited spatial resolution and which are difficult to use in the magnet bore as they interfere with the RF transmit field of the MRI system. In this work an electro-optic sensor is presented that utilizes the Pockels effect to measure the E-field in a clinical MR system with high spatial resolution. This sensor consists of dielectric materials only and thus, it only minimally influences the measured E-field distribution. A 10 m long flexible optical fiber connects the small sensor head to a remote processing unit where the optical signal is transformed into an electrical output signal. Spatially resolved qualitative E-field measurements were performed in a 1.5 T clinical MR system in the vicinity of metallic samples and an active tracking catheter with a resolution of up to 1 mm. The near-field pattern of a resonant U-shaped metallic sample was clearly identified and compared with numerical simulations. A more complex field behavior was found for the tracking catheter where strong E-field enhancements were observed at the distal tip and at its proximal part outside the phantom solution. Due to its sub-mm spatial resolution the optical sensor approach provides detailed insight into the complex and difficult to access field distributions close to implants and metallic structures and has turned out to be promising tool for MRI field and safety inspections.

  9. High spatial resolution analysis of ferromanganese concretions by LA-ICP-MS†

    Directory of Open Access Journals (Sweden)

    Ingri Johan

    2002-06-01

    Full Text Available A procedure was developed for the determination of element distributions in cross-sections of ferromanganese concretions using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS. The effects of carrier flow rates, rf forward power, ablation energy, ablation spot size, repetition rate and number of shots per point on analyte intensity were studied. It is shown that different carrier gas flow rates are required in order to obtain maximum sensitivities for different groups of elements, thus complicating the optimisation of ICP parameters. On the contrary, LA parameters have very similar effects on almost all elements studied, thus providing a common optimum parameter set for the entire mass range. However, for selected LA parameters, the use of compromise conditions was necessary in order to compensate for relatively slow data acquisition by ICP-MS and maintain high spatial resolution without sacrificing the multielemental capabilities of the technique. Possible variations in ablation efficiency were corrected for mathematically using the sum of Fe and Mn intensities. Quantification by external calibration against matrix-matched standards was successfully used for more than 50 elements. These standards, in the form of pressed pellets (no binder, were prepared in-house using ferromanganese concentrates from a deep-sea nodule reference material as well as from shallow-marine concretions varying in size and having different proportions of three major phases: aluminosilicates, Fe- and Mn-oxyhydroxides. Element concentrations in each standard were determined by means of conventional solution nebulisation ICP-MS following acid digestion. Examples of selected inter-element correlations in distribution patterns along the cross-section of a concretion are given.

  10. SU-E-T-244: High Spatial Resolution EBT2 Film Dosimetry.

    Science.gov (United States)

    Poppinga, D; Schoenfeld, A; Poppe, B; Chofor, N

    2012-06-01

    The purpose of this study was to measure depth dose curves and dose effects near high-Z interfaces with radiochromic EBT-2 films reaching a spatial resolution superior to conventional methods with no quality losses. The setup is made of two 12cm stacks of RW3, fixing an EBT2 film in a vertical position. To measure a depth dose curve, the setup was irradiated with a 15MV photon beam (Siemens Primus). Since the film is positioned parallel to the beam propagation, the depth dose curve is measured with only one film per depth. Additionally, a dental gold alloy probe was inserted in the RW3 stack at 6cm depth and the dose enhancement in front of the probe was measured with the method described above. Hereby, the bottom edge of the film touches the probe's surface.The irradiated films were digitized with a resolution of 72dpi using an Epson 10000XL flatbed scanner with a transparency unit and alignment frames. With this setup, the spatial resolution is only limited by the scanning resolution. In order to verify the new measurement method, comparisons of the measured depth dose curves with the conventional method of placing the film orthogonal to the beam propagation showed deviations of lesser than 3%.The comparison of the dental gold measurements with Monte Carlo simulations shows a systematic lower measured dose which is still within 5% consistency. However attention has to be paid in the experimental setup and film preparation. The introduced method shows significant advantages to conventional orthogonal EBT2 film positioning. It shows a very high spatial resolution and the area of interest is only limited by the film size. The method will be used in further studies, to investigate dose profiles and dose effects near interfaces and in inhomogeneities. © 2012 American Association of Physicists in Medicine.

  11. Ultra-high spatial resolution multi-energy CT using photon counting detector technology

    Science.gov (United States)

    Leng, S.; Gutjahr, R.; Ferrero, A.; Kappler, S.; Henning, A.; Halaweish, A.; Zhou, W.; Montoya, J.; McCollough, C.

    2017-03-01

    Two ultra-high-resolution (UHR) imaging modes, each with two energy thresholds, were implemented on a research, whole-body photon-counting-detector (PCD) CT scanner, referred to as sharp and UHR, respectively. The UHR mode has a pixel size of 0.25 mm at iso-center for both energy thresholds, with a collimation of 32 × 0.25 mm. The sharp mode has a 0.25 mm pixel for the low-energy threshold and 0.5 mm for the high-energy threshold, with a collimation of 48 × 0.25 mm. Kidney stones with mixed mineral composition and lung nodules with different shapes were scanned using both modes, and with the standard imaging mode, referred to as macro mode (0.5 mm pixel and 32 × 0.5 mm collimation). Evaluation and comparison of the three modes focused on the ability to accurately delineate anatomic structures using the high-spatial resolution capability and the ability to quantify stone composition using the multi-energy capability. The low-energy threshold images of the sharp and UHR modes showed better shape and texture information due to the achieved higher spatial resolution, although noise was also higher. No noticeable benefit was shown in multi-energy analysis using UHR compared to standard resolution (macro mode) when standard doses were used. This was due to excessive noise in the higher resolution images. However, UHR scans at higher dose showed improvement in multi-energy analysis over macro mode with regular dose. To fully take advantage of the higher spatial resolution in multi-energy analysis, either increased radiation dose, or application of noise reduction techniques, is needed.

  12. Wireless amplified nuclear MR detector (WAND) for high-spatial-resolution MR imaging of internal organs: preclinical demonstration in a rodent model.

    Science.gov (United States)

    Qian, Chunqi; Yu, Xin; Chen, Der-Yow; Dodd, Stephen; Bouraoud, Nadia; Pothayee, Nikorn; Chen, Yun; Beeman, Scott; Bennett, Kevin; Murphy-Boesch, Joseph; Koretsky, Alan

    2013-07-01

    To assess the feasibility of imaging deep-lying internal organs at high spatial resolution by imaging kidney glomeruli in a rodent model with use of a newly developed, wireless amplified nuclear magnetic resonance (MR) detector. This study was approved by the Animal Care and Use Committee at the National Institutes of Health/National Institute of Neurologic Disorder and Stroke. As a preclinical demonstration of this new detection technology, five different millimeter-scale wireless amplified nuclear MR detectors configured as double frequency resonators were chronically implanted on the medial surface of the kidney in five Sprague-Dawley rats for MR imaging at 11.7 T. Among these rats, two were administered gadopentetate dimeglumine to visualize renal tubules on T1-weighted gradient-refocused echo (GRE) images, two were administered cationized ferritin to visualize glomeruli on T2*-weighted GRE images, and the remaining rat was administered both gadopentetate dimeglumine and cationized ferritin to visualize the interleaved pattern of renal tubules and glomeruli. The image intensity in each pixel was compared with the local tissue signal intensity average to identify regions of hyper- or hypointensity. T1-weighted images with 70-μm in-plane resolution and 200-μm section thickness were obtained within 3.2 minutes to image renal tubules, and T2*-weighted images of the same resolution were obtained within 5.8 minutes to image the glomeruli. Hyperintensity from gadopentetate dimeglumine enabled visualization of renal tubules, and hypointensity from cationic ferritin enabled visualization of the glomeruli. High-spatial-resolution images have been obtained to observe kidney microstructures in vivo with a wireless amplified nuclear MR detector.

  13. Wireless Amplified Nuclear MR Detector (WAND) for High-Spatial-Resolution MR Imaging of Internal Organs: Preclinical Demonstration in a Rodent Model

    Science.gov (United States)

    Yu, Xin; Chen, Der-Yow; Dodd, Stephen; Bouraoud, Nadia; Pothayee, Nikorn; Chen, Yun; Beeman, Scott; Bennett, Kevin; Murphy-Boesch, Joseph; Koretsky, Alan

    2013-01-01

    Purpose: To assess the feasibility of imaging deep-lying internal organs at high spatial resolution by imaging kidney glomeruli in a rodent model with use of a newly developed, wireless amplified nuclear magnetic resonance (MR) detector. Materials and Methods: This study was approved by the Animal Care and Use Committee at the National Institutes of Health/National Institute of Neurologic Disorder and Stroke. As a preclinical demonstration of this new detection technology, five different millimeter-scale wireless amplified nuclear MR detectors configured as double frequency resonators were chronically implanted on the medial surface of the kidney in five Sprague-Dawley rats for MR imaging at 11.7 T. Among these rats, two were administered gadopentetate dimeglumine to visualize renal tubules on T1-weighted gradient-refocused echo (GRE) images, two were administered cationized ferritin to visualize glomeruli on T2*-weighted GRE images, and the remaining rat was administered both gadopentetate dimeglumine and cationized ferritin to visualize the interleaved pattern of renal tubules and glomeruli. The image intensity in each pixel was compared with the local tissue signal intensity average to identify regions of hyper- or hypointensity. Results: T1-weighted images with 70-μm in-plane resolution and 200-μm section thickness were obtained within 3.2 minutes to image renal tubules, and T2*-weighted images of the same resolution were obtained within 5.8 minutes to image the glomeruli. Hyperintensity from gadopentetate dimeglumine enabled visualization of renal tubules, and hypointensity from cationic ferritin enabled visualization of the glomeruli. Conclusion: High-spatial-resolution images have been obtained to observe kidney microstructures in vivo with a wireless amplified nuclear MR detector. © RSNA, 2013 Supplemental material: http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.13121352/-/DC1 PMID:23392428

  14. High Spatial Resolution 40Ar/39Ar Geochronology of Lunar Impact Melt Rocks

    Science.gov (United States)

    Mercer, Cameron Mark

    Impact cratering has played a key role in the evolution of the solid surfaces of Solar System bodies. While much of Earth’s impact record has been erased, its Moon preserves an extensive history of bombardment. Quantifying the timing of lunar impact events is crucial to understanding how impacts have shaped the evolution of early Earth, and provides the basis for estimating the ages of other cratered surfaces in the Solar System. Many lunar impact melt rocks are complex mixtures of glassy and crystalline “melt” materials and inherited clasts of pre-impact minerals and rocks. If analyzed in bulk, these samples can yield complicated incremental release 40Ar/39Ar spectra, making it challenging to uniquely interpret impact ages. Here, I have used a combination of high-spatial resolution 40Ar/39Ar geochronology and thermal-kinetic modeling to gain new insights into the impact histories recorded by such lunar samples. To compare my data to those of previous studies, I developed a software tool to account for differences in the decay, isotopic, and monitor age parameters used for different published 40Ar/39Ar datasets. Using an ultraviolet laser ablation microprobe (UVLAMP) system I selectively dated melt and clast components of impact melt rocks collected during the Apollo 16 and 17 missions. UVLAMP 40Ar/39Ar data for samples 77135, 60315, 61015, and 63355 show evidence of open-system behavior, and provide new insights into how to interpret some complexities of published incremental heating 40Ar/39Ar spectra. Samples 77115, 63525, 63549, and 65015 have relatively simple thermal histories, and UVLAMP 40Ar/39Ar data for the melt components of these rocks indicate the timing of impact events—spanning hundreds of millions of years—that influenced the Apollo 16 and 17 sites. My modeling and UVLAMP 40Ar/39Ar data for sample 73217 indicate that some impact melt rocks can quantitatively retain evidence for multiple melt-producing impact events, and imply that such

  15. Intracranial plaque enhancement in patients with cerebrovascular events on high-spatial-resolution MR images.

    Science.gov (United States)

    Qiao, Ye; Zeiler, Steven R; Mirbagheri, Saeedeh; Leigh, Richard; Urrutia, Victor; Wityk, Robert; Wasserman, Bruce A

    2014-05-01

    To characterize intracranial plaque inflammation in vivo by using three-dimensional (3D) high-spatial-resolution contrast material-enhanced black-blood (BB) magnetic resonance (MR) imaging and to investigate the relationship between intracranial plaque inflammation and cerebrovascular ischemic events. The study was approved by the institutional review board and was HIPAA compliant. Twenty-seven patients (19 men; mean age, 56.8 years ± 12.4 [standard deviation]) with cerebrovascular ischemic events (acute stroke, n = 20; subacute stroke, n = 2; chronic stroke, n = 3; transient ischemic attack, n = 2) underwent 3D time-of-flight MR angiography and contrast-enhanced BB 3-T MR imaging for intracranial atherosclerotic disease. Each identified plaque was classified as either culprit (the only or most stenotic lesion upstream from a stroke), probably culprit (not the most stenotic lesion upstream from a stroke), or nonculprit (not within the vascular territory of a stroke). Plaque contrast enhancement was categorized on BB MR images (grade 0, enhancement less than or equal to that of normal arterial walls seen elsewhere; grade 1, enhancement greater than grade 0 but less than that of the pituitary infundibulum; grade 2, enhancement greater than or equal to that of the pituitary infundibulum), and degree of contrast enhancement was calculated. Associations of the likelihood of being a culprit lesion with both plaque contrast enhancement and plaque thickness were estimated with ordinal logistic regression. Seventy-eight plaques were identified in 20 patients with acute stroke (21 [27%] culprit, 12 [15%] probably culprit, and 45 [58%] nonculprit plaques). In these patients, grade 2 contrast enhancement was associated with culprit plaques (odds ratio 34.6; 95% confidence interval: 4.5, 266.5 compared with grade 0) when adjusted for plaque thickness. Grade 0 was observed in only nonculprit plaques. Culprit plaques had a higher degree of contrast enhancement than did

  16. ALMA high spatial resolution observations of the dense molecular region of NGC 6302

    Science.gov (United States)

    Santander-García, M.; Bujarrabal, V.; Alcolea, J.; Castro-Carrizo, A.; Sánchez Contreras, C.; Quintana-Lacaci, G.; Corradi, R. L. M.; Neri, R.

    2017-01-01

    Context. The mechanism behind the shaping of bipolar planetary nebulae is still poorly understood. It is becoming increasingly clear that the main agents must operate at their innermost regions, where a significant equatorial density enhancement should be present and related to the collimation of light and jet launching from the central star preferentially towards the polar directions. Most of the material in this equatorial condensation must be lost during the asymptotic giant branch as stellar wind and later released from the surface of dust grains to the gas phase in molecular form. Accurately tracing the molecule-rich regions of these objects can give valuable insight into the ejection mechanisms themselves. Aims: We investigate the physical conditions, structure and velocity field of the dense molecular region of the planetary nebula NGC 6302 by means of ALMA band 7 interferometric maps. Methods: The high spatial resolution of the 12CO and 13CO J = 3-2 ALMA data allows for an analysis of the geometry of the ejecta in unprecedented detail. We built a spatio-kinematical model of the molecular region with the software SHAPE and performed detailed non-LTE calculations of excitation and radiative transfer with the shapemol plug-in. Results: We find that the molecular region consists of a massive ring out of which a system of fragments of lobe walls emerge and enclose the base of the lobes visible in the optical. The general properties of this region are in agreement with previous works, although the much greater spatial resolution of the data allows for a very detailed description. We confirm that the mass of the molecular region is 0.1 M⊙. Additionally, we report a previously undetected component at the nebular equator, an inner, younger ring inclined 60° with respect to the main ring, showing a characteristic radius of 7.5 × 1016 cm, a mass of 2.7 × 10-3M⊙, and a counterpart in optical images of the nebula. This inner ring has the same kinematical age as

  17. High-spatial resolution numerical simulations of in-water radiative transfer processes

    Science.gov (United States)

    D'Alimonte, D.; Kajiyama, T.; Zibordi, G.

    2012-04-01

    Monte Carlo (MC) simulations of radiative processes allow for addressing optical radiometric problems strictly linked to complex geometries. Within such a context, MC simulations have been used to investigate uncertainties affecting in-water radiometric measurements performed with free-fall optical profilers commonly utilized for the vicarious calibration of space sensors or the validation of satellite ocean color primary products (e.g, the normalized water leaving radiance). Specifically, a MC code (henceforth called MOX) has been developed to simulate in-water and above-water radiometric fields with high spatial-resolution (up to 1 cm) over a 2-dimensional (2D) domain of tens of meters. This has been achieved by exploiting high performance computing (HPC) solutions (e.g., parallel programs and job-scheduling based on novel performance prediction and optimization schemes) to trace up to 10^12 photons. A dedicated study, focused on the simulation of in-water radiometric fields, has led to the generation of virtual optical profiles accounting for perturbations due to light focusing effect by sea-surface gravity and capillary waves at a spatial resolution comparable to that of actual measurements. Different from field experiments, which are often constrained by environmental factors like illumination conditions and sea-water optical properties, numerical simulations permits analyzing realistic cases whereas allowing for a free input parameter selection. MOX simulations have shown that uncertainties induced by focusing effects upon radiometric data products can be reduced by slowing the deployment speed of free-fall optical profilers, rather than increasing the sampling frequency (i.e., while keeping the same number of samples per depth unit). This result has confirmed the appropriateness of profiling techniques (i.e., multicasting) so far solely supported by a limited number of field measurements and has additionally suggested the possibility of investigating further

  18. Best period for high spatial resolution satellite images for the detection of marks of buried structures

    Directory of Open Access Journals (Sweden)

    Dimitrios Kaimaris

    2012-06-01

    Full Text Available Improvements in sensor technology in recent decades led to the creation of ground, air and space imaging systems, whose data can be used in archaeological studies. Greece is one of the lucky areas that are rich in archaeological heritage. The detection of prehistoric/historic undiscovered constructions on satellite images or aerial photos is a complex and complicated matter. These marks are not visible from the ground, they can, however, be traced on satellite or aerial images, because of the differences in tone and texture. These differences appear as crop, soil and shadow marks. Undoubtedly, the detection of buried structures requires a suitable spatial resolution image, taken under appropriate meteorological conditions and during the best period of the vegetation growing cycle. According to the pertinent literature, detecting covered memorials may be achieved either accidentally or, usually, after a systematic investigation based on historical narratives. The purpose of this study is to determine the factors that facilitate or hinder the detection of buried structures through high spatial resolution satellite imagery. In this study, pan sharpened images from the QuickBird-2 satellite were used, of a spatial resolution of 0.60-0.70 m. This study concerns the detection of marks of the ancient Via Egnatia, from the ancient Amphipolis to Philippi (Eastern Macedonia, Greece. We studied different types of vegetation in the region and their phenological cycle. Taking into account the vegetation phenological cycle of the study area as well as the meteorological data, four pan sharpened QuickBird-2 images of a spatial resolution of 0.60–0.70 m. were used, during four different seasons. By processing the four images, we can determine the one acquired during the most appropriate conditions for the detection of buried structures. The application of this methodology in the study area had positive results, and not only was the main purpose of this

  19. Evaluating the Value of High Spatial Resolution in National Capacity Expansion Models using ReEDS: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Krishnan, Venkat; Cole, Wesley

    2016-07-01

    Power sector capacity expansion models (CEMs) have a broad range of spatial resolutions. This paper uses the Regional Energy Deployment System (ReEDS) model, a long-term national scale electric sector CEM, to evaluate the value of high spatial resolution for CEMs. ReEDS models the United States with 134 load balancing areas (BAs) and captures the variability in existing generation parameters, future technology costs, performance, and resource availability using very high spatial resolution data, especially for wind and solar modeled at 356 resource regions. In this paper we perform planning studies at three different spatial resolutions--native resolution (134 BAs), state-level, and NERC region level--and evaluate how results change under different levels of spatial aggregation in terms of renewable capacity deployment and location, associated transmission builds, and system costs. The results are used to ascertain the value of high geographically resolved models in terms of their impact on relative competitiveness among renewable energy resources.

  20. New developments and applications of the MP2RAGE sequence--focusing the contrast and high spatial resolution R1 mapping.

    Directory of Open Access Journals (Sweden)

    José P Marques

    Full Text Available MR structural T1-weighted imaging using high field systems (>3T is severely hampered by the existing large transmit field inhomogeneities. New sequences have been developed to better cope with such nuisances. In this work we show the potential of a recently proposed sequence, the MP2RAGE, to obtain improved grey white matter contrast with respect to conventional T1-w protocols, allowing for a better visualization of thalamic nuclei and different white matter bundles in the brain stem. Furthermore, the possibility to obtain high spatial resolution (0.65 mm isotropic R1 maps fully independent of the transmit field inhomogeneities in clinical acceptable time is demonstrated. In this high resolution R1 maps it was possible to clearly observe varying properties of cortical grey matter throughout the cortex and observe different hippocampus fields with variations of intensity that correlate with known myelin concentration variations.

  1. New developments and applications of the MP2RAGE sequence--focusing the contrast and high spatial resolution R1 mapping.

    Science.gov (United States)

    Marques, José P; Gruetter, Rolf

    2013-01-01

    MR structural T1-weighted imaging using high field systems (>3T) is severely hampered by the existing large transmit field inhomogeneities. New sequences have been developed to better cope with such nuisances. In this work we show the potential of a recently proposed sequence, the MP2RAGE, to obtain improved grey white matter contrast with respect to conventional T1-w protocols, allowing for a better visualization of thalamic nuclei and different white matter bundles in the brain stem. Furthermore, the possibility to obtain high spatial resolution (0.65 mm isotropic) R1 maps fully independent of the transmit field inhomogeneities in clinical acceptable time is demonstrated. In this high resolution R1 maps it was possible to clearly observe varying properties of cortical grey matter throughout the cortex and observe different hippocampus fields with variations of intensity that correlate with known myelin concentration variations.

  2. Comparative study of two whole-body imaging techniques in the case of melanoma metastases: Advantages of multi-contrast MRI examination including a diffusion-weighted sequence in comparison with PET-CT

    Energy Technology Data Exchange (ETDEWEB)

    Laurent, Valerie, E-mail: v.laurent@chu-nancy.f [Department of Adult Radiology, Brabois Hospital, University of Nancy, 54500 Vandoeuvre-Les-Nancy (France); Trausch, Gregory [GE Healthcare Technologies, 283 rue de la Miniere, 78533 Buc CEDEX (France); Bruot, Olivier [Department of Adult Radiology, Brabois Hospital, University of Nancy, 54500 Vandoeuvre-Les-Nancy (France); Olivier, Pierre [Department of Nuclear Medicine, Brabois Hospital, University of Nancy, 54500 Vandoeuvre-Les-Nancy (France); Felblinger, Jacques [IADI Laboratory, INSERM-ERI 13, University of Nancy, 54500 Vandoeuvre-Les-Nancy (France); Regent, Denis [Department of Adult Radiology, Brabois Hospital, University of Nancy, 54500 Vandoeuvre-Les-Nancy (France)

    2010-09-15

    The aim of our study was to compare whole-body MRI (Magnetic Resonance Imaging) with a multi-contrast protocol including a DW (Diffusion Weighted) sequence to PET-CT (Positron Emission Tomography) using {sup 18}FDG (18F-fluoroDeoxyGlucose) for staging advanced melanoma. In a first part, we compared the respective overall accuracy of each modality. We analyzed in a second part the benefits of a DW sequence added to the standard whole-body MRI protocol. Among the population of the 35 patients who experienced the two examinations of our prospective blinded study, we were able to detect 120 lesions and 70 of them were found malignant. The sensitivity and specificity for whole-body MRI were respectively 82% and 97%, while PET-CT reached 72.8% and 92.7%. DW sequence allowed the detection of 14 supplementary malignant lesions (20%) in comparison with standard MRI protocol. Moreover, this technique has been shown to be the most accurate for detecting metastases in the liver, bone, subcutaneous and intra-peritoneal sites. Consequently, a DW sequence should be added systematically to the standard whole-body MRI oncologic protocol because of its high added-value for metastasis detection.

  3. Detection of Urban Land-cover Change in Altamira, the Brazilian Amazon With High Spatial Resolution Multi-sensor Data

    Science.gov (United States)

    Feng, Y.; Lu, D.; Moran, E. F.; Dutra, L. V.; Calvi, M. F.

    2016-12-01

    Abstract:The hydroelectric dam construction in Belo Monte beginning in 2011 has resulted in rapid urban land cover change in Altamira, Para State, Brazil due to boomed population from less than 80 thousand persons before 2010 to more than 150 thousand persons in 2015. The rapid urbanization has produced many problems in urban planning and environmental conditions. It is an urgent work to monitor annual urban land cover change. However, the frequent cloud cover in the moist tropical region is a big problem constraining the acquisition of cloud-free optical sensor data. Thanks to the availability of different satellite images with high spatial resolution and high temporal resolutions, we collected RapidEye imagery in 2011 and 2012, Pleiades imagery in 2013 and 2014, and SPOT 6 imagery in 2015 with spatial resolutions from 0.5 m to 5 m for this research. This research proposed a comprehensive change detection approach using very high spatial resolution multi-sensor satellite images to examine annually urban land cover change in a moist tropical region of the Brazilian Amazon. A hybrid approach consisting of decision tree and cluster analysis based on spectral signatures, segmentation, vegetation indices, and textural images was proposed to classify the images into six land cover classes: impervious surface area, bare soils, water, pasture, primary forest, and non-forest vegetation. In order to improve the classification accuracy, the classified result was visually interpreted for each land cover class and the result was modified if classification errors were identified. The classified images were converted into vector format and object-based change detection approach was used to explore the annual land cover changes. The spatial patterns and annual land cover change rates were analyzed, and they were further related to household survey data to understand the relationships between and interactions of urbanization and population migration and economic conditions

  4. Full-field, high-spatial-resolution detection of local structural damage from low-resolution random strain field measurements

    Science.gov (United States)

    Yang, Yongchao; Sun, Peng; Nagarajaiah, Satish; Bachilo, Sergei M.; Weisman, R. Bruce

    2017-07-01

    Structural damage is typically a local phenomenon that initiates and propagates within a limited area. As such high spatial resolution measurement and monitoring is often needed for accurate damage detection. This requires either significantly increased costs from denser sensor deployment in the case of global simultaneous/parallel measurements, or increased measurement time and labor in the case of global sequential measurements. This study explores the feasibility of an alternative approach to this problem: a computational solution in which a limited set of randomly positioned, low-resolution global strain measurements are used to reconstruct the full-field, high-spatial-resolution, two-dimensional (2D) strain field and rapidly detect local damage. The proposed approach exploits the implicit low-rank and sparse data structure of the 2D strain field: it is highly correlated without many edges and hence has a low-rank structure, unless damage-manifesting itself as sparse local irregularity-is present and alters such a low-rank structure slightly. Therefore, reconstruction of the full-field, high-spatial-resolution strain field from a limited set of randomly positioned low-resolution global measurements is modeled as a low-rank matrix completion framework and damage detection as a sparse decomposition formulation, enabled by emerging convex optimization techniques. Numerical simulations on a plate structure are conducted for validation. The results are discussed and a practical iterative global/local procedure is recommended. This new computational approach should enable the efficient detection of local damage using limited sets of strain measurements.

  5. High spatial resolution magnetic resonance imaging of experimental cerebral venous thrombosis with a blood pool contrast agent.

    Science.gov (United States)

    Spuentrup, E; Wiethoff, A J; Parsons, E C; Spangenberg, P; Stracke, C P

    2010-06-01

    The purpose of this study was to investigate the feasibility of clot visualization in small sinus and cortical veins with contrast enhanced MRA in a cerebral venous thrombosis animal model using a blood pool contrast agent, Gadofosveset, and high spatial resolution imaging. For induction of cerebral venous thrombosis a recently developed combined interventional and microsurgical model was used. Cerebral sinus and cortical vein thrombosis was induced in six pigs. Two further pigs died during the procedure. Standard structural, time-of-flight- and phase contrast-angiograms were followed by fast time resolved high resolution 3D MRA (4D MRA) and subsequent high spatial resolution 3D MRA in the equilibrium phase with and without addition of parallel imaging. Visualization of the clots using the different sequences was subjectively compared and contrast-to-noise ratio (CNR) was assessed. In the remaining six animals the procedure and MR-imaging protocol including administration of Gadofosveset was successfully completed. The 3D high resolution MRA in the equilibrium phase without the addition of parallel imaging was superior to all the other applied MR measurement techniques in terms of visualization of the clots. Only applying this sequence bridging vein thromboses were also seen as a small filling defect with a high CNR of >18. Only the non-accelerated high spatial resolution 3D MRA in the equilibrium in conjunction with the blood pool agent Gadofosveset allows for high-contrast visualization of very small clots in the cerebral sinus and cortical veins. STATEMENT CLINICAL IMPACT: Detection of cortical vein thrombosis is of high clinical impact. Conventional MRI sequences often fail to visualize the clot. We could demonstrate that, in contrast to conventional sequences, with high spatial resolution 3D MRA in the equilibrium in conjunction with the blood pool agent Gadofosveset very small clots in the cerebral sinus and cortical veins could be successfully visualized. We

  6. Cellular and Subcellular Level Localization of Maize Lipids and Metabolites Using High-Spatial Resolution MALDI Mass Spectrometry Imaging.

    Science.gov (United States)

    Dueñas, Maria Emilia; Feenstra, Adam D; Korte, Andrew R; Hinners, Paige; Lee, Young Jin

    2018-01-01

    Recent technological advances have pushed the achievable spatial resolution for mass spectrometry imaging (MSI) to cellular and subcellular levels. Direct visualization of maize tissues by this tool has provided key insights into the localization of metabolites and lipids. This chapter outlines methodology for sample preparation, data acquisition, and data analysis of maize tissue sections using high-spatial resolution matrix-assisted laser desorption ionization (MALDI)-MSI, as well as the incorporation of a multi-resolution optical system, which allows for simple inter-conversion between different resolution setups (5, 10, and 50 μm imaging).

  7. Bayesian Information Criterion Based Feature Filtering for the Fusion of Multiple Features in High-Spatial-Resolution Satellite Scene Classification

    Directory of Open Access Journals (Sweden)

    Da Lin

    2015-01-01

    Full Text Available This paper presents a novel classification method for high-spatial-resolution satellite scene classification introducing Bayesian information criterion (BIC-based feature filtering process to further eliminate opaque and redundant information between multiple features. Firstly, two diverse and complementary feature descriptors are extracted to characterize the satellite scene. Then, sparse canonical correlation analysis (SCCA with penalty function is employed to fuse the extracted feature descriptors and remove the ambiguities and redundancies between them simultaneously. After that, a two-phase Bayesian information criterion (BIC-based feature filtering process is designed to further filter out redundant information. In the first phase, we gradually impose a constraint via an iterative process to set a constraint on the loadings for averting sparse correlation descending below to a lower confidence limit of the approximated canonical correlation. In the second phase, Bayesian information criterion (BIC is utilized to conduct the feature filtering which sets the smallest loading in absolute value to zero in each iteration for all features. Lastly, a support vector machine with pyramid match kernel is applied to obtain the final result. Experimental results on high-spatial-resolution satellite scenes demonstrate that the suggested approach achieves satisfactory performance in classification accuracy.

  8. A novel airport extraction model based on saliency region detection for high spatial resolution remote sensing images

    Science.gov (United States)

    Lv, Wen; Zhang, Libao; Zhu, Yongchun

    2017-06-01

    The airport is one of the most crucial traffic facilities in military and civil fields. Automatic airport extraction in high spatial resolution remote sensing images has many applications such as regional planning and military reconnaissance. Traditional airport extraction strategies usually base on prior knowledge and locate the airport target by template matching and classification, which will cause high computation complexity and large costs of computing resources for high spatial resolution remote sensing images. In this paper, we propose a novel automatic airport extraction model based on saliency region detection, airport runway extraction and adaptive threshold segmentation. In saliency region detection, we choose frequency-tuned (FT) model for computing airport saliency using low level features of color and luminance that is easy and fast to implement and can provide full-resolution saliency maps. In airport runway extraction, Hough transform is adopted to count the number of parallel line segments. In adaptive threshold segmentation, the Otsu threshold segmentation algorithm is proposed to obtain more accurate airport regions. The experimental results demonstrate that the proposed model outperforms existing saliency analysis models and shows good performance in the extraction of the airport.

  9. Development of high spatial resolution X-ray CT system at BL47XU in SPring-8

    CERN Document Server

    Uesugi, K; Yagi, N; Tsuchiyama, A; Nakano, T

    2001-01-01

    High spatial resolution, micrometer range, X-ray CT system has been developed at SPring-8. The experiments were performed at the undulator beam line BL47XU. An 'in-vacuum type' undulator is employed as an X-ray source, and the X-rays are monochromatized with a liquid nitrogen cooled Si(1 1 1) double crystal monochromator. High precision rotation stage with air bearing was used for sample rotation. The transmitted images were obtained with a two-dimensional image detector, which consists of a single crystal phosphor screen (Lu sub 2 SiO sub 5 : Ce), an objective lens and a cooled CCD camera. In this system the smallest effective pixel size was set to 0.5 mu mx0.5 mu m. As a result of the experiments, three-dimensional images of a few micrometer-order texture has been successfully obtained with the developed CT system.

  10. High spatial resolution hard X-ray microscope using X-ray refractive lens and phase contrast imaging experiments

    CERN Document Server

    Kohmura, Y; Takeuchi, A; Takano, H; Suzuki, Y; Ishikawa, T; Ohigashi, T; Yokosuka, H

    2001-01-01

    A high spatial resolution X-ray microscope was constructed using an X-ray refractive lens as an objective. The spatial resolution was tested using 18 keV X-ray. A 0.4 mu m line and 0.4 mu m space tantalum test pattern was successfully resolved. Using the similar setup with the addition of a phase plate, a Zernike type phase-contrast microscopy experiment was carried out for the phase retrieval of the samples. Two-dimensional phase-contrast images were successfully taken for the first time in the hard X-ray region. Images of a gold mesh sample were analyzed and the validity of this method was indicated. An improvement of the lens, however, is required for the precise phase retrieval of the samples.

  11. Road Extraction from High-spatial-resolution Remote Sensing Image by Combining GVF Snake with Salient Features

    Directory of Open Access Journals (Sweden)

    WANG Fengping

    2017-12-01

    Full Text Available The road information in the high-spatial-resolution remote sensing image is of great significance for updating the GIS database. Through analyzing the road features shown in the remote sensing image, this paper presents a road detection method based on salient features and gradient vector flow (GVF Snake. According to the visual cognition theory, the road geometric and radiation features are viewed as salient features in this paper. First, the saliency map is calculated by fusing the color-based and structure-based contrasts, the maximum saliency value is regarded as the seeds of the GVF Snake. Then, a region-growing algorithm is applied to compute the initial boundaries, the energy function of the GVF Snake is minimized by iterative solution of the gradient vector flow model to get the final road information.Experimental results show that the proposed method could enhance the computational efficiency and has good detection accuracy.

  12. Ultra-long high-sensitivity Φ-OTDR for high spatial resolution intrusion detection of pipelines.

    Science.gov (United States)

    Peng, Fei; Wu, Han; Jia, Xin-Hong; Rao, Yun-Jiang; Wang, Zi-Nan; Peng, Zheng-Pu

    2014-06-02

    An ultra-long phase-sensitive optical time domain reflectometry (Φ-OTDR) that can achieve high-sensitivity intrusion detection over 131.5km fiber with high spatial resolution of 8m is presented, which is the longest Φ-OTDR reported to date, to the best of our knowledge. It is found that the combination of distributed Raman amplification with heterodyne detection can extend the sensing distance and enhances the sensitivity substantially, leading to the realization of ultra-long Φ-OTDR with high sensitivity and spatial resolution. Furthermore, the feasibility of applying such an ultra-long Φ-OTDR to pipeline security monitoring is demonstrated and the features of intrusion signal can be extracted with improved SNR by using the wavelet detrending/denoising method proposed.

  13. Two color multichannel heterodyne interferometer set up for high spatial resolution electron density profile measurements in TJ-II

    Energy Technology Data Exchange (ETDEWEB)

    Pedreira, P.; Criado, A. R.; Acedo, P. [Department of Electronics Technology, Universidad Carlos III de Madrid, Leganes, Madrid 28911 (Spain); Esteban, L.; Sanchez, M.; Sanchez, J. [Laboratorio Nacional de Fusion por ConfinamientoMagnetico-CIEMAT, Madrid 28040 (Spain)

    2010-10-15

    A high spatial resolution two color [CO{sub 2}, {lambda}=10.6 {mu}m/Nd:YAG (Nd:YAG denotes neodymium-doped yttrium aluminum garnet), and {lambda}=1.064 {mu}m] expanded-beam multichannel heterodyne interferometer has been installed on the TJ-II stellarator. Careful design of the optical system has allowed complete control on the evolution of both Gaussian beams along the interferometer, as well as the evaluation and optimization of the spatial resolution to be expected in the measurements. Five CO{sub 2} (measurement) channels and three Nd:YAG (vibration compensation) channels have been used to illuminate the plasma with a probe beam of 100 mm size. An optimum interpolation method has been applied to recover both interferometric phasefronts prior to mechanical vibration subtraction. The first results of the installed diagnostic are presented in this paper.

  14. Use of ultra-high spatial resolution aerial imagery in the estimation of chaparral wildfire fuel loads.

    Science.gov (United States)

    Schmidt, Ian T; O'Leary, John F; Stow, Douglas A; Uyeda, Kellie A; Riggan, Phillip J

    2016-12-01

    Development of methods that more accurately estimate spatial distributions of fuel loads in shrublands allows for improved understanding of ecological processes such as wildfire behavior and postburn recovery. The goal of this study is to develop and test remote sensing methods to upscale field estimates of shrubland fuel to broader-scale biomass estimates using ultra-high spatial resolution imagery captured by a light-sport aircraft. The study is conducted on chaparral shrublands located in eastern San Diego County, CA, USA. We measured the fuel load in the field using a regression relationship between basal area and aboveground biomass of shrubs and estimated ground areal coverage of individual shrub species by using ultra-high spatial resolution imagery and image processing routines. Study results show a strong relationship between image-derived shrub coverage and field-measured fuel loads in three even-age stands that have regrown approximately 7, 28, and 68 years since last wildfire. We conducted ordinary least square analysis using ground coverage as the independent variable regressed against biomass. The analysis yielded R 2 values ranging from 0.80 to 0.96 in the older stands for the live shrub species, while R 2 values for species in the younger stands ranged from 0.32 to 0.89. Pooling species-based data into larger sample sizes consisting of a functional group and all-shrub classes while obtaining suitable linear regression models supports the potential for these methods to be used for upscaling fuel estimates to broader areal extents, without having to classify and map shrubland vegetation at the species level.

  15. OSIS: remote sensing code for estimating aerosol optical properties in urban areas from very high spatial resolution images.

    Science.gov (United States)

    Thomas, Colin; Briottet, Xavier; Santer, Richard

    2011-10-01

    The achievement of new satellite or airborne remote sensing instruments enables the more precise study of cities with metric spatial resolutions. For studies such as the radiative characterization of urban features, knowledge of the atmosphere and particularly of aerosols is required to perform first an atmospheric compensation of the remote sensing images. However, to our knowledge, no efficient aerosol characterization technique adapted both to urban areas and to very high spatial resolution images has yet been developed. The goal of this paper is so to present a new code to characterize aerosol optical properties, OSIS, adapted to urban remote sensing images of metric spatial resolution acquired in the visible and near-IR spectral domains. First, a new aerosol characterization method based on the observation of shadow/sun transitions is presented, offering the advantage to avoid the assessment of target reflectances. Its principle and the modeling of the signal used to solve the retrieval equation are then detailed. Finally, a sensitivity study of OSIS from synthetic images simulated by the radiative transfer code AMARTIS v2 is also presented. This study has shown an intrinsic precision of this tool of Δτ(a)=0.1.τ(a) ± (0.02 + 0.4.τ(a)) for retrieval of aerosol optical thicknesses. This study shows that OSIS is a powerful tool for aerosol characterization that has a precision similar to satellite products for the aerosol optical thicknesses retrieval and that can be applied to every very high spatial resolution instrument, multispectral or hyperspectral, airborne or satellite.

  16. OBJECT BASED IMAGE ANALYSIS COMBINING HIGH SPATIAL RESOLUTION IMAGERY AND LASER POINT CLOUDS FOR URBAN LAND COVER

    Directory of Open Access Journals (Sweden)

    X. Zou

    2016-06-01

    Full Text Available With the rapid developments of the sensor technology, high spatial resolution imagery and airborne Lidar point clouds can be captured nowadays, which make classification, extraction, evaluation and analysis of a broad range of object features available. High resolution imagery, Lidar dataset and parcel map can be widely used for classification as information carriers. Therefore, refinement of objects classification is made possible for the urban land cover. The paper presents an approach to object based image analysis (OBIA combing high spatial resolution imagery and airborne Lidar point clouds. The advanced workflow for urban land cover is designed with four components. Firstly, colour-infrared TrueOrtho photo and laser point clouds were pre-processed to derive the parcel map of water bodies and nDSM respectively. Secondly, image objects are created via multi-resolution image segmentation integrating scale parameter, the colour and shape properties with compactness criterion. Image can be subdivided into separate object regions. Thirdly, image objects classification is performed on the basis of segmentation and a rule set of knowledge decision tree. These objects imagery are classified into six classes such as water bodies, low vegetation/grass, tree, low building, high building and road. Finally, in order to assess the validity of the classification results for six classes, accuracy assessment is performed through comparing randomly distributed reference points of TrueOrtho imagery with the classification results, forming the confusion matrix and calculating overall accuracy and Kappa coefficient. The study area focuses on test site Vaihingen/Enz and a patch of test datasets comes from the benchmark of ISPRS WG III/4 test project. The classification results show higher overall accuracy for most types of urban land cover. Overall accuracy is 89.5% and Kappa coefficient equals to 0.865. The OBIA approach provides an effective and convenient way

  17. Species classification using Unmanned Aerial Vehicle (UAV)-acquired high spatial resolution imagery in a heterogeneous grassland

    Science.gov (United States)

    Lu, Bing; He, Yuhong

    2017-06-01

    Investigating spatio-temporal variations of species composition in grassland is an essential step in evaluating grassland health conditions, understanding the evolutionary processes of the local ecosystem, and developing grassland management strategies. Space-borne remote sensing images (e.g., MODIS, Landsat, and Quickbird) with spatial resolutions varying from less than 1 m to 500 m have been widely applied for vegetation species classification at spatial scales from community to regional levels. However, the spatial resolutions of these images are not fine enough to investigate grassland species composition, since grass species are generally small in size and highly mixed, and vegetation cover is greatly heterogeneous. Unmanned Aerial Vehicle (UAV) as an emerging remote sensing platform offers a unique ability to acquire imagery at very high spatial resolution (centimetres). Compared to satellites or airplanes, UAVs can be deployed quickly and repeatedly, and are less limited by weather conditions, facilitating advantageous temporal studies. In this study, we utilize an octocopter, on which we mounted a modified digital camera (with near-infrared (NIR), green, and blue bands), to investigate species composition in a tall grassland in Ontario, Canada. Seven flight missions were conducted during the growing season (April to December) in 2015 to detect seasonal variations, and four of them were selected in this study to investigate the spatio-temporal variations of species composition. To quantitatively compare images acquired at different times, we establish a processing flow of UAV-acquired imagery, focusing on imagery quality evaluation and radiometric correction. The corrected imagery is then applied to an object-based species classification. Maps of species distribution are subsequently used for a spatio-temporal change analysis. Results indicate that UAV-acquired imagery is an incomparable data source for studying fine-scale grassland species composition

  18. Lithographic Microfabrication of a 16-Electrode Array on a Probe Tip for High Spatial Resolution Electrochemical Localization of Exocytosis.

    Science.gov (United States)

    Wigström, Joakim; Dunevall, Johan; Najafinobar, Neda; Lovrić, Jelena; Wang, Jun; Ewing, Andrew G; Cans, Ann-Sofie

    2016-02-16

    We report the lithographic microfabrication of a movable thin film microelectrode array (MEA) probe consisting of 16 platinum band electrodes placed on top of a supporting borosilicate glass substrate. These 1.2 μm wide electrodes were tightly packed and positioned parallel in two opposite rows within a 20 μm × 25 μm square area and with a distance less than 10 μm from the edge of the glass substrate. We demonstrate the ability to control and place the probe in close proximity to the surface of adherent bovine chromaffin cells and to amperometrically record single exocytosis release events with high spatiotemporal resolution. The two-dimensional position of single exocytotic events occurring in the center gap area separating the two rows of MEA band electrodes and that were codetected by electrodes in both rows was determined by analysis of the fractional detection of catecholamine released between electrodes and exploiting random walk simulations. Hence, two-dimensional electrochemical imaging recording of exocytosis release between the electrodes within this area was achieved. Similarly, by modeling the current spikes codetected by parallel adjacent band electrodes positioned in the same electrode row, a one-dimensional imaging of exocytosis with submicrometer resolution was accomplished within the area. The one- and two-dimensional electrochemical imaging using the MEA probe allowed for high spatial resolution of exocytosis activity and revealed heterogeneous release of catecholamine at the chromaffin cell surface.

  19. High spatial resolution infrared micro-spectroscopy reveals the mechanism of leaf lignin decomposition by aquatic fungi.

    Directory of Open Access Journals (Sweden)

    Janice L Kerr

    Full Text Available Organic carbon is a critical component of aquatic systems, providing energy storage and transfer between organisms. Fungi are a major decomposer group in the aquatic carbon cycle, and are one of few groups thought to be capable of breaking down woody (lignified tissue. In this work we have used high spatial resolution (synchrotron light source infrared micro-spectroscopy to study the interaction between aquatic fungi and lignified leaf vein material (xylem from River Redgum trees (E. camaldulensis endemic to the lowland rivers of South-Eastern Australia. The work provides spatially explicit evidence that fungal colonisation of leaf litter involves the oxidative breakdown of lignin immediately adjacent to the fungal tissue and depletion of the lignin-bound cellulose. Cellulose depletion occurs over relatively short length scales (5-15 µm and highlights the likely importance of mechanical breakdown in accessing the carbohydrate content of this resource. Low bioavailability compounds (oxidized lignin and polyphenols of plant origin remain in colonised leaves, even after fungal activity diminishes, and suggests a possible pathway for the sequestration of carbon in wetlands. The work shows that fungi likely have a critical role in the partitioning of lignified material into a biodegradable fraction that can re-enter the aquatic carbon cycle, and a recalcitrant fraction that enters long-term storage in sediments or contribute to the formation of dissolved organic carbon in the water column.

  20. An Object-Based Image Analysis Approach for Detecting Penguin Guano in very High Spatial Resolution Satellite Images

    Directory of Open Access Journals (Sweden)

    Chandi Witharana

    2016-04-01

    Full Text Available The logistical challenges of Antarctic field work and the increasing availability of very high resolution commercial imagery have driven an interest in more efficient search and classification of remotely sensed imagery. This exploratory study employed geographic object-based analysis (GEOBIA methods to classify guano stains, indicative of chinstrap and Adélie penguin breeding areas, from very high spatial resolution (VHSR satellite imagery and closely examined the transferability of knowledge-based GEOBIA rules across different study sites focusing on the same semantic class. We systematically gauged the segmentation quality, classification accuracy, and the reproducibility of fuzzy rules. A master ruleset was developed based on one study site and it was re-tasked “without adaptation” and “with adaptation” on candidate image scenes comprising guano stains. Our results suggest that object-based methods incorporating the spectral, textural, spatial, and contextual characteristics of guano are capable of successfully detecting guano stains. Reapplication of the master ruleset on candidate scenes without modifications produced inferior classification results, while adapted rules produced comparable or superior results compared to the reference image. This work provides a road map to an operational “image-to-assessment pipeline” that will enable Antarctic wildlife researchers to seamlessly integrate VHSR imagery into on-demand penguin population census.

  1. Fragmentation of urban forms and the environmental consequences: results from a high-spatial resolution model system

    Science.gov (United States)

    Tang, U. W.; Wang, Z. S.

    2008-10-01

    Each city has its unique urban form. The importance of urban form on sustainable development has been recognized in recent years. Traditionally, air quality modelling in a city is in a mesoscale with grid resolution of kilometers, regardless of its urban form. This paper introduces a GIS-based air quality and noise model system developed to study the built environment of highly compact urban forms. Compared with traditional mesoscale air quality model system, the present model system has a higher spatial resolution down to individual buildings along both sides of the street. Applying the developed model system in the Macao Peninsula with highly compact urban forms, the average spatial resolution of input and output data is as high as 174 receptor points per km2. Based on this input/output dataset with a high spatial resolution, this study shows that even the highly compact urban forms can be fragmented into a very small geographic scale of less than 3 km2. This is due to the significant temporal variation of urban development. The variation of urban form in each fragment in turn affects air dispersion, traffic condition, and thus air quality and noise in a measurable scale.

  2. High Spatial Resolution Soil Moisture with Passive Active Sensors Using a Change Detection Approach: Studies Using SMAPVEX12 Data

    Science.gov (United States)

    Fang, B.; Lakshmi, V.; Bindlish, R.; Jackson, T. J.

    2014-12-01

    Soil moisture is an important variable in many areas of geosciences. The passive microwave sensors have been providing soil moisture of various spatial resolutions and are available for all-weather conditions. However, restricted by the antenna diameter of microwave radiometer, the spatial resolution of passive microwave soil moisture product is at tens of kilometers and needs to be improved for many applications. The SMAP (Soil Moisture Active Passive) is set to be launched in late 2014 and will be the first mission to provide L-band radar/radiometer soil moisture retrievals at three resolutions. The SMAPVEX12 is a pre-launch field validation experiment for evaluating and testing the soil moisture retrievals acquired from SMAP satellite. Airborne data using PALS (Passive/Active L-band Sensor) at two along-track resolutions (650 m and 1590 m) and UAVSAR (Uninhabited Aerial Vehicle Synthetic Aperture Radar) at 5 m spatial resolution as well as in-situ measurements were collected during the campaign. The study will implement a Single Channel Algorithm (SCA) to retrieve soil moisture from high/low altitude PALS L-band radiometer observations, as well as produce downscaled soil moisture change by combining low spatial resolution soil moisture retrievals and high spatial resolution PALS L-band radar observations through a change-detection algorithm, which models the relationship between change in radar backscatter and the change in soil moisture.

  3. High-Spatial-Resolution OH PLIF Visualization in a Cavity-Stabilized Ethylene-Air Turbulent Flame

    Science.gov (United States)

    Geipel, Clayton M.; Rockwell, Robert D.; Chelliah, Harsha K.; Cutler, Andrew D.; Spelker, Christopher A.; Hashem, Zeid; Danehy, Paul M.

    2017-01-01

    High-spatial-resolution OH planar laser-induced fluorescence was measured for a premixed ethylene-air turbulent flame in an electrically-heated Mach 2 continuous-flow facility (University of Virginia Supersonic Combustion Facility, Configuration E.) The facility comprised a Mach 2 nozzle, an isolator with flush-wall fuel injectors, a combustor with optical access, and an extender. The flame was anchored at a cavity flameholder with a backward-facing step of height 9 mm. The temperature-insensitive Q1(8) transition of OH was excited using laser light of wavelength 283.55 nm. A spatial filter was used to create a laser sheet approximately 25 microns thick based on full-width at half maximum (FWHM). Extension tubes increased the magnification of an intensified camera system, achieving in-plane resolution of 40 microns based on a 50% modulation transfer function (MTF). The facility was tested with total temperature 1200 K, total pressure 300 kPa, local fuel/air equivalence ratios of approximately 0.4, and local Mach number of approximately 0.73 in the combustor. A test case with reduced total temperature and another with reduced equivalence ratio were also tested. PLIF images were acquired along a streamwise plane bisecting the cavity flameholder, from the backward facing step to 120 mm downstream of the step. The smallest observed features in the flow had width of approximately 110 microns. Flame surface density was calculated for OH PLIF images.

  4. High-Spatial-Resolution OH and CH2O PLIF Visualization in a Dual-Mode Scramjet Combustor

    Science.gov (United States)

    Geipel, Clayton M.

    2017-01-01

    A high-spatial-resolution planar laser-induced fluorescence (PLIF) imaging system was constructed and used to image a cavity-stabilized, premixed ethylene-air flame. The flame was created within a continuous flow, electrically-heated supersonic combustion facility consisting of a Mach 2 nozzle, an isolator with flush-wall fuel injectors, a combustor with a cavity flameholder of height 9 mm and optical access, and an extender. Tests were conducted at total temperature 1200 K, total pressure 300 kPa, equivalence ratio near 0.4 in the combustor, and Mach number near 0.6 in the combustor. A frequency-doubled Nd:YAG laser pumped a dye laser, which produced light at 283.55 nm. The beam was shaped into a light sheet with full width half-maximum 25 microns, which illuminated a streamwise plane that bisected the cavity. An intensified camera system imaged OH in this plane with a square 6.67 mm field of view and in-plane resolution 39 microns. Images were taken between the backward-facing step and 120 mm downstream of the step. OH structures as small as 110 microns were observed. CH2O was excited using 352.48 nm light; the smallest observed CH2O structures were approximately 200 microns wide. Approximately 15,000 images per species were processed and used to compute composite images.

  5. Object-based habitat mapping using very high spatial resolution multispectral and hyperspectral imagery with LiDAR data

    Science.gov (United States)

    Onojeghuo, Alex Okiemute; Onojeghuo, Ajoke Ruth

    2017-07-01

    This study investigated the combined use of multispectral/hyperspectral imagery and LiDAR data for habitat mapping across parts of south Cumbria, North West England. The methodology adopted in this study integrated spectral information contained in pansharp QuickBird multispectral/AISA Eagle hyperspectral imagery and LiDAR-derived measures with object-based machine learning classifiers and ensemble analysis techniques. Using the LiDAR point cloud data, elevation models (such as the Digital Surface Model and Digital Terrain Model raster) and intensity features were extracted directly. The LiDAR-derived measures exploited in this study included Canopy Height Model, intensity and topographic information (i.e. mean, maximum and standard deviation). These three LiDAR measures were combined with spectral information contained in the pansharp QuickBird and Eagle MNF transformed imagery for image classification experiments. A fusion of pansharp QuickBird multispectral and Eagle MNF hyperspectral imagery with all LiDAR-derived measures generated the best classification accuracies, 89.8 and 92.6% respectively. These results were generated with the Support Vector Machine and Random Forest machine learning algorithms respectively. The ensemble analysis of all three learning machine classifiers for the pansharp QuickBird and Eagle MNF fused data outputs did not significantly increase the overall classification accuracy. Results of the study demonstrate the potential of combining either very high spatial resolution multispectral or hyperspectral imagery with LiDAR data for habitat mapping.

  6. SCENE CLASSFICATION BASED ON THE SEMANTIC-FEATURE FUSION FULLY SPARSE TOPIC MODEL FOR HIGH SPATIAL RESOLUTION REMOTE SENSING IMAGERY

    Directory of Open Access Journals (Sweden)

    Q. Zhu

    2016-06-01

    Full Text Available Topic modeling has been an increasingly mature method to bridge the semantic gap between the low-level features and high-level semantic information. However, with more and more high spatial resolution (HSR images to deal with, conventional probabilistic topic model (PTM usually presents the images with a dense semantic representation. This consumes more time and requires more storage space. In addition, due to the complex spectral and spatial information, a combination of multiple complementary features is proved to be an effective strategy to improve the performance for HSR image scene classification. But it should be noticed that how the distinct features are fused to fully describe the challenging HSR images, which is a critical factor for scene classification. In this paper, a semantic-feature fusion fully sparse topic model (SFF-FSTM is proposed for HSR imagery scene classification. In SFF-FSTM, three heterogeneous features – the mean and standard deviation based spectral feature, wavelet based texture feature, and dense scale-invariant feature transform (SIFT based structural feature are effectively fused at the latent semantic level. The combination of multiple semantic-feature fusion strategy and sparse based FSTM is able to provide adequate feature representations, and can achieve comparable performance with limited training samples. Experimental results on the UC Merced dataset and Google dataset of SIRI-WHU demonstrate that the proposed method can improve the performance of scene classification compared with other scene classification methods for HSR imagery.

  7. Scene Classfication Based on the Semantic-Feature Fusion Fully Sparse Topic Model for High Spatial Resolution Remote Sensing Imagery

    Science.gov (United States)

    Zhu, Qiqi; Zhong, Yanfei; Zhang, Liangpei

    2016-06-01

    Topic modeling has been an increasingly mature method to bridge the semantic gap between the low-level features and high-level semantic information. However, with more and more high spatial resolution (HSR) images to deal with, conventional probabilistic topic model (PTM) usually presents the images with a dense semantic representation. This consumes more time and requires more storage space. In addition, due to the complex spectral and spatial information, a combination of multiple complementary features is proved to be an effective strategy to improve the performance for HSR image scene classification. But it should be noticed that how the distinct features are fused to fully describe the challenging HSR images, which is a critical factor for scene classification. In this paper, a semantic-feature fusion fully sparse topic model (SFF-FSTM) is proposed for HSR imagery scene classification. In SFF-FSTM, three heterogeneous features - the mean and standard deviation based spectral feature, wavelet based texture feature, and dense scale-invariant feature transform (SIFT) based structural feature are effectively fused at the latent semantic level. The combination of multiple semantic-feature fusion strategy and sparse based FSTM is able to provide adequate feature representations, and can achieve comparable performance with limited training samples. Experimental results on the UC Merced dataset and Google dataset of SIRI-WHU demonstrate that the proposed method can improve the performance of scene classification compared with other scene classification methods for HSR imagery.

  8. Enhanced sensitivity for high spatial resolution lipid analysis by negative ion mode matrix assisted laser desorption ionization imaging mass spectrometry.

    Science.gov (United States)

    Angel, Peggi M; Spraggins, Jeffrey M; Baldwin, H Scott; Caprioli, Richard

    2012-02-07

    We have achieved enhanced lipid imaging to a ~10 μm spatial resolution using negative ion mode matrix assisted laser desorption ionization (MALDI) imaging mass spectrometry, sublimation of 2,5-dihydroxybenzoic acid as the MALDI matrix, and a sample preparation protocol that uses aqueous washes. We report on the effect of treating tissue sections by washing with volatile buffers at different pHs prior to negative ion mode lipid imaging. The results show that washing with ammonium formate, pH 6.4, or ammonium acetate, pH 6.7, significantly increases signal intensity and number of analytes recorded from adult mouse brain tissue sections. Major lipid species measured were glycerophosphoinositols, glycerophosphates, glycerolphosphoglycerols, glycerophosphoethanolamines, glycerophospho-serines, sulfatides, and gangliosides. Ion images from adult mouse brain sections that compare washed and unwashed sections are presented and show up to 5-fold increases in ion intensity for washed tissue. The sample preparation protocol has been found to be applicable across numerous organ types and significantly expands the number of lipid species detectable by imaging mass spectrometry at high spatial resolution. © 2012 American Chemical Society

  9. High spatial resolution and temporally resolved T2* mapping of normal human myocardium at 7.0 Tesla: an ultrahigh field magnetic resonance feasibility study.

    Directory of Open Access Journals (Sweden)

    Fabian Hezel

    Full Text Available Myocardial tissue characterization using T(2(* relaxation mapping techniques is an emerging application of (preclinical cardiovascular magnetic resonance imaging. The increase in microscopic susceptibility at higher magnetic field strengths renders myocardial T(2(* mapping at ultrahigh magnetic fields conceptually appealing. This work demonstrates the feasibility of myocardial T(2(* imaging at 7.0 T and examines the applicability of temporally-resolved and high spatial resolution myocardial T(2(* mapping. In phantom experiments single cardiac phase and dynamic (CINE gradient echo imaging techniques provided similar T(2(* maps. In vivo studies showed that the peak-to-peak B(0 difference following volume selective shimming was reduced to approximately 80 Hz for the four chamber view and mid-ventricular short axis view of the heart and to 65 Hz for the left ventricle. No severe susceptibility artifacts were detected in the septum and in the lateral wall for T(2(* weighting ranging from TE = 2.04 ms to TE = 10.2 ms. For TE >7 ms, a susceptibility weighting induced signal void was observed within the anterior and inferior myocardial segments. The longest T(2(* values were found for anterior (T(2(* = 14.0 ms, anteroseptal (T(2(* = 17.2 ms and inferoseptal (T(2(* = 16.5 ms myocardial segments. Shorter T(2(* values were observed for inferior (T(2(* = 10.6 ms and inferolateral (T(2(* = 11.4 ms segments. A significant difference (p = 0.002 in T(2(* values was observed between end-diastole and end-systole with T(2(* changes of up to approximately 27% over the cardiac cycle which were pronounced in the septum. To conclude, these results underscore the challenges of myocardial T(2(* mapping at 7.0 T but demonstrate that these issues can be offset by using tailored shimming techniques and dedicated acquisition schemes.

  10. Six-Fold Acceleration of High-Spatial Resolution 3D SPACE MRI of the Knee Through Incoherent k-Space Undersampling and Iterative Reconstruction-First Experience.

    Science.gov (United States)

    Fritz, Jan; Raithel, Esther; Thawait, Gaurav K; Gilson, Wesley; Papp, Derek F

    2016-06-01

    The aim of this study was to prospectively test the hypothesis that 6-fold acceleration of a 3-dimensional (3D) turbo spin echo (TSE) magnetic resonance imaging (MRI) pulse sequence with k-space undersampling and iterative reconstruction is feasible for fast high spatial resolution MRI of the knee, while yielding similar image quality and diagnostic performance when compared with a conventional 2-dimensional (2D) TSE MRI standard. The study was approved by the institutional review board. A 10-minute isotropic 3D TSE knee protocol consisting of accelerated intermediate-weighted (repetition time, 900 milliseconds; echo time, 29 milliseconds; voxel size, 0.5 × 0.5 × 0.5 mm; acquisition time, 4:45 minutes) and fat-saturated T2-weighted (repetition time, 900 milliseconds; echo time, 92 milliseconds; voxel size, 0.5 × 0.5 × 0.5 mm; acquisition time, 5:10 minutes) SPACE (sampling perfection with application optimized contrast using different flip angle evolutions) sequence prototypes was compared against a 20-minute 2D TSE standard protocol. The accelerated SPACE sequences were equipped with an optional variable-density poisson-disc pattern as an undersampling mask. An undersampling factor of 0.17 was chosen (6-fold acceleration compared with an acquisition with full sampling). An iterative, sensitivity encoding-type reconstruction with L1 norm-based regularization term was used. The study was performed on a 3 T MRI system using a 15-channel transmit/receive knee coil. The study groups included 15 asymptomatic volunteers and 15 patient volunteers. Quantitative and qualitative assessments were performed by 2 observers. Outcome variables included signal and contrast-to-noise ratio, image quality, and diagnostic accuracy. Qualitative and quantitative measurements were statistically analyzed using nonparametric tests. P values of less than 0.01 were considered significant. The signal-to-noise ratios of 2D and 3D MRI were similar with the exception of fluid, which was

  11. High spatial resolution burn severity mapping of the New Jersey Pine Barrens with WorldView-3 near-infrared and shortwave infrared imagery

    Science.gov (United States)

    Timothy A. Warner; Nicholas S. Skowronski; Michael R. Gallagher

    2017-01-01

    The WorldView-3 (WV-3) sensor, launched in 2014, is the first highspatial resolution scanner to acquire imagery in the shortwave infrared (SWIR). A spectral ratio of the SWIR combined with the nearinfrared (NIR) can potentially provide an effective differentiation of wildfire burn severity. Previous high spatial resolution sensors were limited to data fromthe visible...

  12. Data acquisition of space heat demand with high spatial resolution. Digital heat demand map; Erfassung des raeumlich hoch aufgeloesten Raumwaermebedarfs. Digitale Waermebedarfskarte

    Energy Technology Data Exchange (ETDEWEB)

    Blesl, Markus; Kempe, Stephan [Stuttgart Univ. (DE). Inst. fuer Energiewirtschaft und Rationelle Energieanwendung (IER); Huther, Heiko [AGFW - Der Energieeffizienzverband fuer Waerme, Kaelte und KWK e. V., Frankfurt am Main (Germany)

    2010-01-15

    For a selective and systematic expansion of the district heating capacity, detailed knowledge of the heat demand of a given town district is required. For this, a method was developed for automatic data acquisition of the space heat demand of an urban area with high spatial resolution. The method was applied exemplarily to the inner city of the town of Esslingen. (orig.)

  13. An Improved Method for Producing High Spatial-Resolution NDVI Time Series Datasets with Multi-Temporal MODIS NDVI Data and Landsat TM/ETM+ Images

    Directory of Open Access Journals (Sweden)

    Yuhan Rao

    2015-06-01

    Full Text Available Due to technical limitations, it is impossible to have high resolution in both spatial and temporal dimensions for current NDVI datasets. Therefore, several methods are developed to produce high resolution (spatial and temporal NDVI time-series datasets, which face some limitations including high computation loads and unreasonable assumptions. In this study, an unmixing-based method, NDVI Linear Mixing Growth Model (NDVI-LMGM, is proposed to achieve the goal of accurately and efficiently blending MODIS NDVI time-series data and multi-temporal Landsat TM/ETM+ images. This method firstly unmixes the NDVI temporal changes in MODIS time-series to different land cover types and then uses unmixed NDVI temporal changes to predict Landsat-like NDVI dataset. The test over a forest site shows high accuracy (average difference: −0.0070; average absolute difference: 0.0228; and average absolute relative difference: 4.02% and computation efficiency of NDVI-LMGM (31 seconds using a personal computer. Experiments over more complex landscape and long-term time-series demonstrated that NDVI-LMGM performs well in each stage of vegetation growing season and is robust in regions with contrasting spatial and spatial variations. Comparisons between NDVI-LMGM and current methods (i.e., Spatial and Temporal Adaptive Reflectance Fusion Model (STARFM, Enhanced STARFM (ESTARFM and Weighted Linear Model (WLM show that NDVI-LMGM is more accurate and efficient than current methods. The proposed method will benefit land surface process research, which requires a dense NDVI time-series dataset with high spatial resolution.

  14. Airborne DOAS retrievals of methane, carbon dioxide, and water vapor concentrations at high spatial resolution: application to AVIRIS-NG

    Science.gov (United States)

    Thorpe, Andrew K.; Frankenberg, Christian; Thompson, David R.; Duren, Riley M.; Aubrey, Andrew D.; Bue, Brian D.; Green, Robert O.; Gerilowski, Konstantin; Krings, Thomas; Borchardt, Jakob; Kort, Eric A.; Sweeney, Colm; Conley, Stephen; Roberts, Dar A.; Dennison, Philip E.

    2017-10-01

    At local scales, emissions of methane and carbon dioxide are highly uncertain. Localized sources of both trace gases can create strong local gradients in its columnar abundance, which can be discerned using absorption spectroscopy at high spatial resolution. In a previous study, more than 250 methane plumes were observed in the San Juan Basin near Four Corners during April 2015 using the next-generation Airborne Visible/Infrared Imaging Spectrometer (AVIRIS-NG) and a linearized matched filter. For the first time, we apply the iterative maximum a posteriori differential optical absorption spectroscopy (IMAP-DOAS) method to AVIRIS-NG data and generate gas concentration maps for methane, carbon dioxide, and water vapor plumes. This demonstrates a comprehensive greenhouse gas monitoring capability that targets methane and carbon dioxide, the two dominant anthropogenic climate-forcing agents. Water vapor results indicate the ability of these retrievals to distinguish between methane and water vapor despite spectral interference in the shortwave infrared. We focus on selected cases from anthropogenic and natural sources, including emissions from mine ventilation shafts, a gas processing plant, tank, pipeline leak, and natural seep. In addition, carbon dioxide emissions were mapped from the flue-gas stacks of two coal-fired power plants and a water vapor plume was observed from the combined sources of cooling towers and cooling ponds. Observed plumes were consistent with known and suspected emission sources verified by the true color AVIRIS-NG scenes and higher-resolution Google Earth imagery. Real-time detection and geolocation of methane plumes by AVIRIS-NG provided unambiguous identification of individual emission source locations and communication to a ground team for rapid follow-up. This permitted verification of a number of methane emission sources using a thermal camera, including a tank and buried natural gas pipeline.

  15. GIEMS-D3: A new long-term, dynamical, high-spatial resolution inundation extent dataset at global scale

    Science.gov (United States)

    Aires, Filipe; Miolane, Léo; Prigent, Catherine; Pham Duc, Binh; Papa, Fabrice; Fluet-Chouinard, Etienne; Lehner, Bernhard

    2017-04-01

    The Global Inundation Extent from Multi-Satellites (GIEMS) provides multi-year monthly variations of the global surface water extent at 25kmx25km resolution. It is derived from multiple satellite observations. Its spatial resolution is usually compatible with climate model outputs and with global land surface model grids but is clearly not adequate for local applications that require the characterization of small individual water bodies. There is today a strong demand for high-resolution inundation extent datasets, for a large variety of applications such as water management, regional hydrological modeling, or for the analysis of mosquitos-related diseases. A new procedure is introduced to downscale the GIEMS low spatial resolution inundations to a 3 arc second (90 m) dataset. The methodology is based on topography and hydrography information from the HydroSHEDS database. A new floodability index is adopted and an innovative smoothing procedure is developed to ensure the smooth transition, in the high-resolution maps, between the low-resolution boxes from GIEMS. Topography information is relevant for natural hydrology environments controlled by elevation, but is more limited in human-modified basins. However, the proposed downscaling approach is compatible with forthcoming fusion with other more pertinent satellite information in these difficult regions. The resulting GIEMS-D3 database is the only high spatial resolution inundation database available globally at the monthly time scale over the 1993-2007 period. GIEMS-D3 is assessed by analyzing its spatial and temporal variability, and evaluated by comparisons to other independent satellite observations from visible (Google Earth and Landsat), infrared (MODIS) and active microwave (SAR).

  16. High spatial resolution myocardial perfusion imaging during high dose dobutamine/atropine stress magnetic resonance using k-t SENSE.

    Science.gov (United States)

    Gebker, R; Jahnke, C; Manka, R; Frick, M; Hucko, T; Kozerke, S; Schnackenburg, B; Fleck, E; Paetsch, I

    2012-07-26

    To prospectively evaluate the feasibility and diagnostic accuracy of high spatial resolution myocardial perfusion imaging during high dose dobutamine/atropine stress magnetic resonance (DSMR) for the detection of coronary artery disease (CAD). DSMR-wall motion was combined with perfusion imaging (DSMR-perfusion) in 78 patients prior to clinically indicated invasive coronary angiography. For DSMR-perfusion an in-plane spatial resolution of 1.5 × 1.5mm(2) was attained by using 8 × k-space and time sensitivity encoding (k-t SENSE). Image quality and extent of artifacts during perfusion imaging were evaluated. Wall motion and perfusion data were interpreted sequentially. Significant CAD (stenosis ≥ 70%) was present in 52 patients and involved 86 coronary territories. One patient did not reach target heart rate despite maximum infusion of dobutamine/atropine. Two studies (3%) were non-diagnostic due k-t SENSE related artifacts resulting from insufficient breathhold capability. Overall image quality was good. Dark-rim artifacts were limited to the endocardial border at a mean width of 1.8mm. The addition of DSMR-perfusion to DSMR-wall motion data improved sensitivity for the detection of CAD (92% vs. 81%, P=0.03) and accurate determination of disease extent (85% vs. 66% of territories, Pspatial resolution DSMR-perfusion imaging at maximum stress level was feasible, improved sensitivity over DSMR-wall motion for the detection of CAD and allowed an accurate determination of disease extent. Specificity of DSMR-perfusion with k-t SENSE improved compared to prior studies using lower spatial resolution. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  17. Ontology-Guided Image Interpretation for GEOBIA of High Spatial Resolution Remote Sense Imagery: A Coastal Area Case Study

    Directory of Open Access Journals (Sweden)

    Helingjie Huang

    2017-03-01

    Full Text Available Image interpretation is a major topic in the remote sensing community. With the increasing acquisition of high spatial resolution (HSR remotely sensed images, incorporating geographic object-based image analysis (GEOBIA is becoming an important sub-discipline for improving remote sensing applications. The idea of integrating the human ability to understand images inspires research related to introducing expert knowledge into image object–based interpretation. The relevant work involved three parts: (1 identification and formalization of domain knowledge; (2 image segmentation and feature extraction; and (3 matching image objects with geographic concepts. This paper presents a novel way that combines multi-scaled segmented image objects with geographic concepts to express context in an ontology-guided image interpretation. Spectral features and geometric features of a single object are extracted after segmentation and topological relationships are also used in the interpretation. Web ontology language–query language (OWL-QL formalize domain knowledge. Then the interpretation matching procedure is implemented by the OWL-QL query-answering. Compared with a supervised classification, which does not consider context, the proposed method validates two HSR images of coastal areas in China. Both the number of interpreted classes increased (19 classes over 10 classes in Case 1 and 12 classes over seven in Case 2, and the overall accuracy improved (0.77 over 0.55 in Case 1 and 0.86 over 0.65 in Case 2. The additional context of the image objects improved accuracy during image classification. The proposed approach shows the pivotal role of ontology for knowledge-guided interpretation.

  18. Performance assessment of the single photon emission microscope: high spatial resolution SPECT imaging of small animal organs

    Energy Technology Data Exchange (ETDEWEB)

    Mejia, J. [Hospital Israelita Albert Einstein, Instituto do Cérebro, São Paulo, SP (Brazil); Reis, M.A. [Hospital Israelita Albert Einstein, Instituto do Cérebro, São Paulo, SP (Brazil); Laboratório Interdisciplinar de Neurociências Clínicas, Departamento de Psiquiatria, Universidade Federal de São Paulo, São Paulo, SP (Brazil); Miranda, A.C.C. [Hospital Israelita Albert Einstein, Instituto do Cérebro, São Paulo, SP (Brazil); Batista, I.R. [Hospital Israelita Albert Einstein, Instituto do Cérebro, São Paulo, SP (Brazil); Laboratório Interdisciplinar de Neurociências Clínicas, Departamento de Psiquiatria, Universidade Federal de São Paulo, São Paulo, SP (Brazil); Barboza, M.R.F.; Shih, M.C. [Hospital Israelita Albert Einstein, Instituto do Cérebro, São Paulo, SP (Brazil); Fu, G. [GE Global Research, Schenectady, NY (United States); Chen, C.T. [Department of Radiology, University of Chicago, Chicago, IL (United States); Meng, L.J. [Department of Nuclear, Plasma and Radiological Engineering, University of Illinois, Urbana-Champaign, IL (United States); Bressan, R.A. [Hospital Israelita Albert Einstein, Instituto do Cérebro, São Paulo, SP (Brazil); Laboratório Interdisciplinar de Neurociências Clínicas, Departamento de Psiquiatria, Universidade Federal de São Paulo, São Paulo, SP (Brazil); Amaro, E. Jr [Hospital Israelita Albert Einstein, Instituto do Cérebro, São Paulo, SP (Brazil)

    2013-11-06

    The single photon emission microscope (SPEM) is an instrument developed to obtain high spatial resolution single photon emission computed tomography (SPECT) images of small structures inside the mouse brain. SPEM consists of two independent imaging devices, which combine a multipinhole collimator, a high-resolution, thallium-doped cesium iodide [CsI(Tl)] columnar scintillator, a demagnifying/intensifier tube, and an electron-multiplying charge-coupling device (CCD). Collimators have 300- and 450-µm diameter pinholes on tungsten slabs, in hexagonal arrays of 19 and 7 holes. Projection data are acquired in a photon-counting strategy, where CCD frames are stored at 50 frames per second, with a radius of rotation of 35 mm and magnification factor of one. The image reconstruction software tool is based on the maximum likelihood algorithm. Our aim was to evaluate the spatial resolution and sensitivity attainable with the seven-pinhole imaging device, together with the linearity for quantification on the tomographic images, and to test the instrument in obtaining tomographic images of different mouse organs. A spatial resolution better than 500 µm and a sensitivity of 21.6 counts·s{sup -1}·MBq{sup -1} were reached, as well as a correlation coefficient between activity and intensity better than 0.99, when imaging {sup 99m}Tc sources. Images of the thyroid, heart, lungs, and bones of mice were registered using {sup 99m}Tc-labeled radiopharmaceuticals in times appropriate for routine preclinical experimentation of <1 h per projection data set. Detailed experimental protocols and images of the aforementioned organs are shown. We plan to extend the instrument's field of view to fix larger animals and to combine data from both detectors to reduce the acquisition time or applied activity.

  19. Combination of high spatial resolution and low minimum detection limit using thinned specimens in cutting-edge electron probe microanalysis

    Energy Technology Data Exchange (ETDEWEB)

    Kubo, Yugo, E-mail: kubo-yugo@sei.co.jp; Hamada, Kotaro

    2015-10-15

    The effect of sample thickness on the spatial resolution and minimum detection limit (MDL) has been investigated for field-emission electron probe microanalysis with wavelength dispersive X-ray spectroscopy (FE-EPMA–WDX). Indium gallium phosphide samples thinned to thicknesses of about 100, 130, 210, 310, and 430 nm provided effective thin-sample FE-EPMA–WDX in the resolution range of 40–350 nm and MDL range of 13,000–600 ppm (mass). A comparison of the FE-EPMA results for thin and bulk samples demonstrated that thin-sample FE-EPMA can achieve both higher sensitivity and better spatial resolution than is possible using bulk samples. Most of the X-rays that determine the MDL are generated in a surface region of the sample with a depth of approximately 300 nm. The spatial resolution and MDL can be tuned by the sample thickness. Furthermore, analysis of small amounts of Cl in SiO{sub 2} indicated that thin-sample FE-EPMA can realize a spatial resolution and MDL of 41 nm and 446 ppm at I{sub prob}=50 nA, respectively, whereas bulk-sample FE-EPMA offers a resolution of only 348 nm and MDL of 426 ppm. - Highlights: • Mechanism for FE-EPMA combining high spatial resolution with a low detection limit. • Spatial resolution and minimum detection limit controllable by sample thickness. • Achievement of a combined resolution and detection limit of 41 nm and 446 ppm. • Spatial resolution and detection limit for FE-EPMA–WDX and FE-SEM–EDX.

  20. Airborne DOAS retrievals of methane, carbon dioxide, and water vapor concentrations at high spatial resolution: application to AVIRIS-NG

    Directory of Open Access Journals (Sweden)

    A. K. Thorpe

    2017-10-01

    Full Text Available At local scales, emissions of methane and carbon dioxide are highly uncertain. Localized sources of both trace gases can create strong local gradients in its columnar abundance, which can be discerned using absorption spectroscopy at high spatial resolution. In a previous study, more than 250 methane plumes were observed in the San Juan Basin near Four Corners during April 2015 using the next-generation Airborne Visible/Infrared Imaging Spectrometer (AVIRIS-NG and a linearized matched filter. For the first time, we apply the iterative maximum a posteriori differential optical absorption spectroscopy (IMAP-DOAS method to AVIRIS-NG data and generate gas concentration maps for methane, carbon dioxide, and water vapor plumes. This demonstrates a comprehensive greenhouse gas monitoring capability that targets methane and carbon dioxide, the two dominant anthropogenic climate-forcing agents. Water vapor results indicate the ability of these retrievals to distinguish between methane and water vapor despite spectral interference in the shortwave infrared. We focus on selected cases from anthropogenic and natural sources, including emissions from mine ventilation shafts, a gas processing plant, tank, pipeline leak, and natural seep. In addition, carbon dioxide emissions were mapped from the flue-gas stacks of two coal-fired power plants and a water vapor plume was observed from the combined sources of cooling towers and cooling ponds. Observed plumes were consistent with known and suspected emission sources verified by the true color AVIRIS-NG scenes and higher-resolution Google Earth imagery. Real-time detection and geolocation of methane plumes by AVIRIS-NG provided unambiguous identification of individual emission source locations and communication to a ground team for rapid follow-up. This permitted verification of a number of methane emission sources using a thermal camera, including a tank and buried natural gas pipeline.

  1. Evaluation of the use of high spatial resolution AOD retrievals from MODIS on air quality monitoring system in urban areas

    Science.gov (United States)

    Castanho, A. D.; Natali, L.; Prinn, R.; Molina, L.; Artaxo, P.; Mattoo, S.; Remer, L.; Chin, M.

    2007-12-01

    The aerosol quality monitoring system in most mega-cities is based on a network of ground-based stations essentially measuring aerosol mass concentrations in one or two particle size ranges (usually PM10 and PM2.5). Satellite retrieval of aerosol optical depth (AOD) over urban areas has become an extremely important additional source of aerosol data as urbanization increases exponentially worldwide, and is critical in megacities without ground-based networks. Progress in this satellite domain will provide an alternative tool to complement the monitoring of urban air-pollution control efforts. Recent studies have compared quantitative AOD data from the MODIS sensor on the Terra and Aqua satellite (10 km x 10 km pixels) with data from ground-based particulate matter monitoring networks and have shown that the remote sensing product can be used quantitatively to estimate PM2.5 under certain conditions. Nevertheless, major improvements in the accuracy and spatial resolution of the satellite products are required for air quality applications in urban areas. We discuss the possibilities and limitations of the use of satellite AOD products with high spatial resolution over urban areas as air quality monitoring tools. The AOD product from satellites was compared specifically to the measured ground based PM2.5 mass concentrations of aerosols in different urban areas including Mexico City and Sao Paulo. We will present the results of a study evaluating the use of the remote sensing of aerosols as a complementary tool to the ground based monitoring of aerosols in the atmosphere in urban areas.

  2. Performance assessment of the single photon emission microscope: high spatial resolution SPECT imaging of small animal organs

    Directory of Open Access Journals (Sweden)

    J. Mejia

    2013-11-01

    Full Text Available The single photon emission microscope (SPEM is an instrument developed to obtain high spatial resolution single photon emission computed tomography (SPECT images of small structures inside the mouse brain. SPEM consists of two independent imaging devices, which combine a multipinhole collimator, a high-resolution, thallium-doped cesium iodide [CsI(Tl] columnar scintillator, a demagnifying/intensifier tube, and an electron-multiplying charge-coupling device (CCD. Collimators have 300- and 450-µm diameter pinholes on tungsten slabs, in hexagonal arrays of 19 and 7 holes. Projection data are acquired in a photon-counting strategy, where CCD frames are stored at 50 frames per second, with a radius of rotation of 35 mm and magnification factor of one. The image reconstruction software tool is based on the maximum likelihood algorithm. Our aim was to evaluate the spatial resolution and sensitivity attainable with the seven-pinhole imaging device, together with the linearity for quantification on the tomographic images, and to test the instrument in obtaining tomographic images of different mouse organs. A spatial resolution better than 500 µm and a sensitivity of 21.6 counts·s-1·MBq-1 were reached, as well as a correlation coefficient between activity and intensity better than 0.99, when imaging 99mTc sources. Images of the thyroid, heart, lungs, and bones of mice were registered using 99mTc-labeled radiopharmaceuticals in times appropriate for routine preclinical experimentation of <1 h per projection data set. Detailed experimental protocols and images of the aforementioned organs are shown. We plan to extend the instrument's field of view to fix larger animals and to combine data from both detectors to reduce the acquisition time or applied activity.

  3. Monitoring of vegetation impact due to trampling on Cadillac Mountain summit using high spatial resolution remote sensing data sets.

    Science.gov (United States)

    Kim, Min-Kook; Daigle, John J

    2012-11-01

    Cadillac Mountain--the highest peak along the eastern seaboard of the United States--is a major tourist destination in Acadia National Park, Maine. Managing vegetation impact due to trampling on the Cadillac Mountain summit is extremely challenging because of the large number of visitors and the general open nature of landscape in this fragile subalpine environmental setting. Since 2000, more intensive management strategies--based on placing physical barriers and educational messages for visitors--have been employed to protect threatened vegetation, decrease vegetation impact, and enhance vegetation recovery in the vicinity of the summit loop trail. The primary purpose of this study was to evaluate the effect of the management strategies employed. For this purpose, vegetation cover changes between 2001 and 2007 were detected using multispectral high spatial resolution remote sensing data sets. A normalized difference vegetation index was employed to identify the rates of increase and decrease in the vegetation areas. Three buffering distances (30, 60, and 90 m) from the edges of the trail were used to define multiple spatial extents of the site, and the same spatial extents were employed at a nearby control site that had no visitors. No significant differences were detected between the mean rates of vegetation increase and decrease at the experimental site compared with a nearby control site in the case of a small spatial scale (≤30 m) comparison (in all cases P > 0.05). However, in the medium (≤60 m) and large (≤90 m) spatial scales, the rates of increased vegetation were significantly greater and rates of decreased vegetation significantly lower at the experimental site compared with the control site (in all cases P vegetation at the site level. Management implications are explored in terms of the spatial strategies used to decrease the impact of trampling on vegetation.

  4. A KERNEL METHOD BASED ON TOPIC MODEL FOR VERY HIGH SPATIAL RESOLUTION (VHSR REMOTE SENSING IMAGE CLASSIFICATION

    Directory of Open Access Journals (Sweden)

    L. Wu

    2016-06-01

    Full Text Available A kernel-based method for very high spatial resolution remote sensing image classification is proposed in this article. The new kernel method is based on spectral-spatial information and structure information as well, which is acquired from topic model, Latent Dirichlet Allocation model. The final kernel function is defined as K = u1Kspec + u2Kspat + u3Kstru, in which Kspec, Kspat, Kstru are radial basis function (RBF and u1 + u2 + u3 = 1. In the experiment, comparison with three other kernel methods, including the spectral-based, the spectral- and spatial-based and the spectral- and structure-based method, is provided for a panchromatic QuickBird image of a suburban area with a size of 900 × 900 pixels and spatial resolution of 0.6 m. The result shows that the overall accuracy of the spectral- and structure-based kernel method is 80 %, which is higher than the spectral-based kernel method, as well as the spectral- and spatial-based which accuracy respectively is 67 % and 74 %. What's more, the accuracy of the proposed composite kernel method that jointly uses the spectral, spatial, and structure information is highest among the four methods which is increased to 83 %. On the other hand, the result of the experiment also verifies the validity of the expression of structure information about the remote sensing image.

  5. The Hestia Project: High Spatial Resolution Fossil Fuel Carbon Dioxide Emissions Quantification at Hourly Scale in Indianapolis, USA

    Science.gov (United States)

    Zhou, Y.; Gurney, K. R.

    2009-12-01

    In order to advance the scientific understanding of carbon exchange with the land surface and contribute to sound, quantitatively-based U.S. climate change policy interests, quantification of greenhouse gases emissions drivers at fine spatial and temporal scales is essential. Quantification of fossil fuel CO2 emissions, the primary greenhouse gases, has become a key component to cost-effective CO2 emissions mitigation options and a carbon trading system. Called the ‘Hestia Project’, this pilot study generated CO2 emissions down to high spatial resolution and hourly scale for the greater Indianapolis region in the USA through the use of air quality and traffic monitoring data, remote sensing, GIS, and building energy modeling. The CO2 emissions were constructed from three data source categories: area, point, and mobile. For the area source emissions, we developed an energy consumption model using DOE/EIA survey data on building characteristics and energy consumption. With the Vulcan Project’s county-level CO2 emissions and simulated building energy consumption, we quantified the CO2 emissions for each individual building by allocating Vulcan emissions to roughly 50,000 structures in Indianapolis. The temporal pattern of CO2 emissions in each individual building was developed based on temporal patterns of energy consumption. The point sources emissions were derived from the EPA National Emissions Inventory data and effluent monitoring of electricity producing facilities. The mobile source CO2 emissions were estimated at the month/county scale using the Mobile6 combustion model and the National Mobile Inventory Model database. The month/county scale mobile source CO2 emissions were downscaled to the “native” spatial resolution of road segments every hour using a GIS road atlas and traffic monitoring data. The result is shown in Figure 1. The resulting urban-scale inventory can serve as a baseline of current CO2 emissions and should be of immediate use to

  6. A spectral-structural bag-of-features scene classifier for very high spatial resolution remote sensing imagery

    Science.gov (United States)

    Zhao, Bei; Zhong, Yanfei; Zhang, Liangpei

    2016-06-01

    Land-use classification of very high spatial resolution remote sensing (VHSR) imagery is one of the most challenging tasks in the field of remote sensing image processing. However, the land-use classification is hard to be addressed by the land-cover classification techniques, due to the complexity of the land-use scenes. Scene classification is considered to be one of the expected ways to address the land-use classification issue. The commonly used scene classification methods of VHSR imagery are all derived from the computer vision community that mainly deal with terrestrial image recognition. Differing from terrestrial images, VHSR images are taken by looking down with airborne and spaceborne sensors, which leads to the distinct light conditions and spatial configuration of land cover in VHSR imagery. Considering the distinct characteristics, two questions should be answered: (1) Which type or combination of information is suitable for the VHSR imagery scene classification? (2) Which scene classification algorithm is best for VHSR imagery? In this paper, an efficient spectral-structural bag-of-features scene classifier (SSBFC) is proposed to combine the spectral and structural information of VHSR imagery. SSBFC utilizes the first- and second-order statistics (the mean and standard deviation values, MeanStd) as the statistical spectral descriptor for the spectral information of the VHSR imagery, and uses dense scale-invariant feature transform (SIFT) as the structural feature descriptor. From the experimental results, the spectral information works better than the structural information, while the combination of the spectral and structural information is better than any single type of information. Taking the characteristic of the spatial configuration into consideration, SSBFC uses the whole image scene as the scope of the pooling operator, instead of the scope generated by a spatial pyramid (SP) commonly used in terrestrial image classification. The experimental

  7. High spatial resolution WorldView-2 imagery for mapping NDVI and its relationship to temporal urban landscape evapotranspiration factors

    Science.gov (United States)

    Nouri, Hamideh; Beecham, Simon; Anderson, Sharolyn; Nagler, Pamela

    2014-01-01

    Evapotranspiration estimation has benefitted from recent advances in remote sensing and GIS techniques particularly in agricultural applications rather than urban environments. This paper explores the relationship between urban vegetation evapotranspiration (ET) and vegetation indices derived from newly-developed high spatial resolution WorldView-2 imagery. The study site was Veale Gardens in Adelaide, Australia. Image processing was applied on five images captured from February 2012 to February 2013 using ERDAS Imagine. From 64 possible two band combinations of WorldView-2, the most reliable one (with the maximum median differences) was selected. Normalized Difference Vegetation Index (NDVI) values were derived for each category of landscape cover, namely trees, shrubs, turf grasses, impervious pavements, and water bodies. Urban landscape evapotranspiration rates for Veale Gardens were estimated through field monitoring using observational-based landscape coefficients. The relationships between remotely sensed NDVIs for the entire Veale Gardens and for individual NDVIs of different vegetation covers were compared with field measured urban landscape evapotranspiration rates. The water stress conditions experienced in January 2013 decreased the correlation between ET and NDVI with the highest relationship of ET-Landscape NDVI (Landscape Normalized Difference Vegetation Index) for shrubs (r2 = 0.66) and trees (r2 = 0.63). However, when the January data was excluded, there was a significant correlation between ET and NDVI. The highest correlation for ET-Landscape NDVI was found for the entire Veale Gardens regardless of vegetation type (r2 = 0.95, p > 0.05) and the lowest one was for turf (r2 = 0.88, p > 0.05). In support of the feasibility of ET estimation by WV2 over a longer period, an algorithm recently developed that estimates evapotranspiration rates based on the Enhanced Vegetation Index (EVI) from MODIS was employed. The results revealed a significant positive

  8. Modeling Above-Ground Biomass Across Multiple Circum-Arctic Tundra Sites Using High Spatial Resolution Remote Sensing

    Science.gov (United States)

    Räsänen, Aleksi; Juutinen, Sari; Aurela, Mika; Virtanen, Tarmo

    2017-04-01

    Biomass is one of the central bio-geophysical variables in Earth observation for tracking plant productivity, and flow of carbon, nutrients, and water. Most of the satellite based biomass mapping exercises in Arctic environments have been performed by using rather coarse spatial resolution data, e.g. Landsat and AVHRR which have spatial resolutions of 30 m and >1 km, respectively. While the coarse resolution images have high temporal resolution, they are incapable of capturing the fragmented nature of tundra environment and fine-scale changes in vegetation and carbon exchange patterns. Very high spatial resolution (VHSR, spatial resolution 0.5-2 m) satellite images have the potential to detect environmental variables with an ecologically sound spatial resolution. The usage of VHSR images has, nevertheless, been modest so far in biomass modeling in the Arctic. Our objectives were to use VHSR for predicting above ground biomass in tundra landscapes, evaluate whether a common predictive model can be applied across circum-Arctic tundra and peatland sites having different types of vegetation, and produce knowledge on distribution of plant functional types (PFT) in these sites. Such model development is dependent on ground-based surveys of vegetation with the same spatial resolution and extent with the VHSR images. In this study, we conducted ground-based surveys of vegetation composition and biomass in four different arctic tundra or peatland areas located in Russia, Canada, and Finland. First, we sorted species into PFTs and developed PFT-specific models to predict biomass on the basis of non-destructive measurements (cover, height). Second, we predicted overall biomass on landscape scale by combinations of single bands and vegetation indices of very high resolution satellite images (QuickBird or WorldView-2 images of the eight sites). We compared area-specific empirical regression models and common models that were applied across all sites. We found that NDVI was

  9. Characterization of solar cells. New techniques with high spatial resolution; Entwicklung neuer Verfahren zur raeumlich hochaufloesenden Charakterisierung von Solarzellen

    Energy Technology Data Exchange (ETDEWEB)

    Schwalm, Michael

    2011-06-16

    Today's raising demand for energy relies to a degree of 85% on the consumption of fossil fuels. A change to regenerative forms of energy is an important and inevitable step in order to face the challenges of climate change and fading natural resources. Photovoltaic's (PV) plays a special role within the various forms of renewable energy since it converts sunlight, our most important and virtually endless energy source, directly into electricity. However, currently available PV-systems are still very expensive and, in combination with their relatively low performance, can hardly or cannot compete with conventional sources of energy from an economical point of view. One possibility to overcome this problem is the combination of highly efficient multi junction solar cells with cost-efficient concentrator optics that focus the incident sunlight to a small spot. The material system (GaIn)(NAs) is envisioned to play an important role in a future generation of multi junction solar cells for concentrator applications being a further development of existing device concepts. However, especially the carrier diffusion lengths in (GaIn)(NAs)-based solar cell layers are currently to low for the fabrication of highly efficient PV-structures. In this work, two novel techniques for the characterization of solar cells are developed and evaluated by experiments on test structures and numerical simulations. Both are based on the measurement of laser-induced currents. Spatially-resolved photocurrent spectroscopy (SRPS) allows a spatially-resolved determination of locally induced photocurrents at a fixed bias voltage while spatially-resolved IV-characteristics (SRIV) are measurements of local I-V-characteristics at a certain position. It is found that SRPS and SRIV allow for a reliable and meaningful characterization of solar cell prototypes with a high spatial resolution. Especially the local p-n-parameters of the sample become accessible. These are the short circuit current

  10. Indoor air quality (IAQ) assessment in a multistorey shopping mall by high-spatial-resolution monitoring of volatile organic compounds (VOC).

    Science.gov (United States)

    Amodio, M; Dambruoso, P R; de Gennaro, Gianluigi; de Gennaro, L; Loiotile, A Demarinis; Marzocca, A; Stasi, F; Trizio, L; Tutino, M

    2014-12-01

    In order to assess indoor air quality (IAQ), two 1-week monitoring campaigns of volatile organic compounds (VOC) were performed in different areas of a multistorey shopping mall. High-spatial-resolution monitoring was conducted at 32 indoor sites located in two storehouses and in different departments of a supermarket. At the same time, VOC concentrations were monitored in the mall and parking lot area as well as outdoors. VOC were sampled at 48-h periods using diffusive samplers suitable for thermal desorption. The samples were then analyzed with gas chromatography-mass spectrometry (GC-MS). The data analysis and chromatic maps indicated that the two storehouses had the highest VOC concentrations consisting principally of terpenes. These higher TVOC concentrations could be a result of the low efficiency of the air exchange and intake systems, as well as the large quantity of articles stored in these small spaces. Instead, inside the supermarket, the food department was the most critical area for VOC concentrations. To identify potential emission sources in this department, a continuous VOC analyzer was used. The findings indicated that the highest total VOC concentrations were present during cleaning activities and that these activities were carried out frequently in the food department. The study highlights the importance of conducting both high-spatial-resolution monitoring and high-temporal-resolution monitoring. The former was able to identify critical issues in environments with a complex emission scenario while the latter was useful in interpreting the dynamics of each emission source.

  11. High-spatial-resolution whole-body MR angiography with high-acceleration parallel acquisition and 32-channel 3.0-T unit: initial experience.

    Science.gov (United States)

    Nael, Kambiz; Fenchel, Michael; Krishnam, Mayil; Laub, Gerhard; Finn, J Paul; Ruehm, Stefan G

    2007-03-01

    The purpose of this HIPAA-compliant study was to prospectively evaluate the technical feasibility of a multistation high-spatial-resolution whole-body magnetic resonance (MR) angiography protocol in which high-acceleration parallel imaging (with acceleration factors of three and four) is performed with a 32-channel 3.0-T MR system. After institutional review board approval and written informed consent were obtained, 10 healthy volunteers (four men and six women aged 23-68 years) and four patients (two men and two women aged 56-79 years) suspected of having peripheral vascular disease underwent multistation whole-body contrast material-enhanced MR angiography. Use of multiarray surface coil technology and highly accelerated generalized autocalibrating partially parallel acquisition enabled the acquisition of isotropic high-spatial-resolution three-dimensional data sets for multiple stations. Two radiologists independently evaluated arterial image quality and presence of arterial stenoses. All examinations yielded good or excellent image quality. Interobserver agreement was excellent (kappa = 0.92; 95% confidence interval: 0.86, 0.96). Multistation whole-body MR angiography with high-acceleration parallel acquisition is feasible at 3.0 T. Further clinical studies combined with ongoing optimization of radiofrequency systems and coils seem warranted to advance the potential of this technology. (c) RSNA, 2007.

  12. Calibration of a high spatial resolution laser two-color heterodyne interferometer for density profile measurements in the TJ-II stellarator.

    Science.gov (United States)

    Acedo, Pablo; Pedreira, P; Criado, A R; Lamela, Horacio; Sánchez, Miguel; Sánchez, Joaquín

    2008-10-01

    A high spatial resolution two-color (CO(2), lambda=10.6 microm, He-Ne, lambda=633 nm) interferometer for density profile measurements in the TJ-II stellarator is under development and installation, based in the currently operational single channel two-color heterodyne interferometer. To achieve the objectives of 32 channels, with 4-5 mm lateral separation between plasma chords, careful design and calibration of the interferometric waveforms for both the measurement and vibration compensation wavelengths are undertaken. The first step has been to set up in our laboratories an expanded-beam heterodyne/homodyne interferometer to evaluate the quality of both interferometric wavefronts, a reported source of poor vibration compensation and thus low resolution in the density profile measurements. This novel interferometric setup has allowed us to calibrate the spatial resolution in the profile measurements resulting in approximately 2 mm lateral resolution in the reconstruction of the interferometric wavefront.

  13. Regional-Scale High Spatial Resolution Mapping of Aboveground Net Primary Productivity (ANPP from Field Survey and Landsat Data: A Case Study for the Country of Wales

    Directory of Open Access Journals (Sweden)

    Emma J. Tebbs

    2017-08-01

    Full Text Available This paper presents an alternative approach for high spatial resolution vegetation productivity mapping at a regional scale, using a combination of Normalised Difference Vegetation Index (NDVI imagery and widely distributed ground-based Above-ground Net Primary Production (ANPP estimates. Our method searches through all available single-date NDVI imagery to identify the images which give the best NDVI–ANPP relationship. The derived relationships are then used to predict ANPP values outside of field survey plots. This approach enables the use of the high spatial resolution (30 m Landsat 8 sensor, despite its low revisit frequency that is further reduced by cloud cover. This is one of few studies to investigate the NDVI–ANPP relationship across a wide range of temperate habitats and strong relationships were observed (R2 = 0.706, which increased when only grasslands were considered (R2 = 0.833. The strongest NDVI–ANPP relationships occurred during the spring “green-up” period. A reserved subset of 20% of ground-based ANPP estimates was used for validation and results showed that our method was able to estimate ANPP with a RMSE of 15–21%. This work is important because we demonstrate a general methodological framework for mapping of ANPP from local to regional scales, with the potential to be applied to any temperate ecosystems with a pronounced green up period. Our approach allows spatial extrapolation outside of field survey plots to produce a continuous surface product, useful for capturing spatial patterns and representing small-scale heterogeneity, and well-suited for modelling applications. The data requirements for implementing this approach are also discussed.

  14. Synergic Use of Sentinel-1 and Sentinel-2 Images for Operational Soil Moisture Mapping at High Spatial Resolution over Agricultural Areas

    Directory of Open Access Journals (Sweden)

    Mohammad El Hajj

    2017-12-01

    Full Text Available Soil moisture mapping at a high spatial resolution is very important for several applications in hydrology, agriculture and risk assessment. With the arrival of the free Sentinel data at high spatial and temporal resolutions, the development of soil moisture products that can better meet the needs of users is now possible. In this context, the main objective of the present paper is to develop an operational approach for soil moisture mapping in agricultural areas at a high spatial resolution over bare soils, as well as soils with vegetation cover. The developed approach is based on the synergic use of radar and optical data. A neural network technique was used to develop an operational method for soil moisture estimates. Three inversion SAR (Synthetic Aperture Radar configurations were tested: (1 VV polarization; (2 VH polarization; and (3 both VV and VH polarization, all in addition to the NDVI information extracted from optical images. Neural networks were developed and validated using synthetic and real databases. The results showed that the use of a priori information on the soil moisture condition increases the precision of the soil moisture estimates. The results showed that VV alone provides better accuracy on the soil moisture estimates than VH alone. In addition, the use of both VV and VH provides similar results, compared to VV alone. In conclusion, the soil moisture could be estimated in agricultural areas with an accuracy of approximately 5 vol % (volumetric unit expressed in percent. Better results were obtained for soil with a moderate surface roughness (for root mean surface height between 1 and 3 cm. The developed approach could be applied for agricultural plots with an NDVI lower than 0.75.

  15. High spatial-resolution CE-MRA of the carotid circulation with parallel imaging: comparison of image quality between 2 different acceleration factors at 3.0 Tesla.

    Science.gov (United States)

    Nael, Kambiz; Ruehm, Stefan G; Michaely, Henrik J; Pope, Whitney; Laub, Gerhard; Finn, J Paul; Villablanca, J Pablo

    2006-04-01

    We sought to evaluate and compare the image quality and vessel delineation of the carotid arteries with high spatial-resolution contrast-enhanced MRA (CE-MRA) at 3.0 T using integrated parallel acquisition (iPAT) with acceleration factors of 2 and 4. Using an 8-channel neurovascular array coil, we performed prospective high-spatial resolution CE-MRA at 3.0 T of the head and neck on 24 patients (11 men, 13 women, ages 37-89) with suspected arterio-occlusive disease who were assigned randomly to 2 groups. Twelve patients (group A) were examined with a 3D-GRE sequence using iPAT with acceleration factor of 2. For the next 12 patients (group B) a near-identical sequence with an acceleration factor of 4 was applied. Higher iPAT factors were used to increase the spatial-resolution while keeping scan time unchanged. Two volunteers were scanned by both protocols. Phantom measurements were performed to assess the signal-to-noise ratio (SNR). The presence of artifact, noise, image quality of the arterial segments, and the presence and degree of arterial stenosis were evaluated independently by 2 radiologists. Statistical analysis of data was performed by using Wilcoxon rank sum test and 2-sample Student t test (P acceleration factor of 4 was used (P acceleration factor (iPAT-4) results in superior depiction of small intracranial arterial segments. Imaging at higher magnetic field strength, in addition to the use of an optimized 8-channel array coil, provides sufficient SNR to support faster parallel acquisition protocols, leading to improved spatial-resolution. More extensive clinical studies are warranted to establish the range of applications and confirm the accuracy of the technique.

  16. High spatial resolution particle detectors

    Science.gov (United States)

    Boatner, Lynn A.; Mihalczo, John T.

    2012-09-04

    Disclosed below are representative embodiments of methods, apparatus, and systems for detecting particles, such as radiation or charged particles. One exemplary embodiment disclosed herein is particle detector comprising an optical fiber with a first end and second end opposite the first end. The optical fiber of this embodiment further comprises a doped region at the first end and a non-doped region adjacent to the doped region. The doped region of the optical fiber is configured to scintillate upon interaction with a target particle, thereby generating one or more photons that propagate through the optical fiber and to the second end. Embodiments of the disclosed technology can be used in a variety of applications, including associated particle imaging and cold neutron scattering.

  17. Novel nanocrystalline Gd 2O 3(Eu) scintillator screens with a micro-pixel structure for high spatial resolution X-ray imaging

    Science.gov (United States)

    Cha, Bo Kyung; Lee, Seung Jun; Muralidharan, P.; Kim, Do Kyung; Kim, Jong Yul; Cho, Gyuseong; Jeon, Sungchae; Huh, Young

    2011-10-01

    We developed a novel pixel-structured scintillation screen with nanocrystalline Gd 2O 3:Eu particle sizes for high spatial resolution X-ray imaging detectors. Nanocrystalline Gd 2O 3:Eu scintillators were successfully synthesized with a hydrothermal method and a subsequent calcination treatment, which were used as a material for converting incident X-rays into visible light. In this work, silicon-based pixel structures with different 100, 50 and 30 μm pixel sizes, a 10 μm wall width and a 120 μm thickness were prepared with the standard photolithography and the deep reactive ion etching (DRIE) process. Subsequently, a micro-pixel-structured scintillation screen was fabricated by adding the synthesized nanocrystalline Gd 2O 3:Eu scintillating phosphor to pixel-structured silicon arrays. Additionally, X-ray imaging performance such as relative light intensity, X-ray to light response and the spatial resolution in terms of modulation transfer function (MTF) were measured by using an X-ray source and a lens-coupled charge coupled device (CCD) camera system. The light intensity of the pixel-structured nanocrystalline Gd 2O 3:Eu screen was much higher than that of a pixel-structured sample made with a commercial microcrystalline Gd 2O 3:Eu product due to the density of the nanocrystalline Gd 2O 3:Eu scintillating powder-filled silicon structure. As the pixel size of the pixel-structured silicon decreased, the light intensity decreased. However, as the pixel size decreased, the spatial resolution significantly improved with no evident crosstalk from the emitted optical photons between adjacent scintillating pixels. The MTF of pixel-structured nanocrystalline Gd 2O 3:Eu screens with a 100 and a 50 μm pixel size was 20% and 30% at 6 lp/mm, respectively. As a result, this new technology showed that a microchannel structure based on a nanocrystalline Gd 2O 3:Eu scintillator could provide higher light intensity and high spatial resolution imaging compared to conventional

  18. Equilibrium-Phase High Spatial Resolution Contrast-Enhanced MR Angiography at 1.5T in Preoperative Imaging for Perforator Flap Breast Reconstruction

    Science.gov (United States)

    Boetes, Carla; Van Der Hulst, René; Lataster, Arno; Van Mulken, Tom; Wildberger, Joachim; de Haan, Michiel; Leiner, Tim

    2013-01-01

    Objectives The aim was (i) to evaluate the accuracy of equilibrium-phase high spatial resolution (EP) contrast-enhanced magnetic resonance angiography (CE-MRA) at 1.5T using a blood pool contrast agent for the preoperative evaluation of deep inferior epigastric artery perforator branches (DIEP), and (ii) to compare image quality with conventional first-pass CE-MRA. Methods Twenty-three consecutive patients were included. All patients underwent preoperative CE-MRA to determine quality and location of DIEP. First-pass imaging after a single bolus injection of 10 mL gadofosveset trisodium was followed by EP imaging. MRA data were compared to intra-operative findings, which served as the reference standard. Results There was 100% agreement between EP CE-MRA and surgical findings in identifying the single best perforator branch. All EP acquisitions were of diagnostic quality, whereas in 10 patients the quality of the first-pass acquisition was qualified as non-diagnostic. Both signal- and contrast-to-noise ratios were significantly higher for EP imaging in comparison with first-pass acquisitions (p<0.01). Conclusions EP CE-MRA of DIEP in the preoperative evaluation of patients undergoing a breast reconstruction procedure is highly accurate in identifying the single best perforator branch at 1.5Tesla (T). Besides accuracy, image quality of EP imaging proved superior to conventional first-pass CE-MRA. PMID:24009659

  19. Online monitoring of the distributed lateral displacement in large AC power generators using a high spatial resolution Brillouin optical fiber sensor

    Science.gov (United States)

    Dong, Yongkang; Bao, Xiaoyi; Chen, Liang

    2011-11-01

    We report for the first time, to the best of our knowledge, online monitoring of the distributed lateral displacement in large AC power generators using high spatial resolution differential pulse-width pair Brillouin optical time-domain analysis (DPP-BOTDA). To perform the measurement of distributed lateral displacements with periods of only a few cm in large AC power generators, a 2 cm spatial resolution strain measurement is realized using the differential pulse pair of 8/8.2 ns in DPP-BOTDA, and then the lateral displacements are reconstructed according to the strain-displacement relation with the assumption of a sine shape function. Using different fiberglass ripple springs, two types of lateral displacement with periods of 3 and 3.25 cm are demonstrated, obtaining a maximum displacement of 0.43 mm with a measurement accuracy of ~ 40 µm. This provides the information on the stator coil tightness through online monitoring of the distributed lateral displacement caused by the fiberglass ripple springs, and ensures safe operating conditions for large AC power generators. In addition, the large number of sensing points associated with distributed optical fiber sensors make it economically and technically practical to monitor large numbers of key components in a generator without any interference from the large magnetic and electrical fields.

  20. Combining HJ CCD, GF-1 WFV and MODIS Data to Generate Daily High Spatial Resolution Synthetic Data for Environmental Process Monitoring.

    Science.gov (United States)

    Wu, Mingquan; Huang, Wenjiang; Niu, Zheng; Wang, Changyao

    2015-08-20

    The limitations of satellite data acquisition mean that there is a lack of satellite data with high spatial and temporal resolutions for environmental process monitoring. In this study, we address this problem by applying the Enhanced Spatial and Temporal Adaptive Reflectance Fusion Model (ESTARFM) and the Spatial and Temporal Data Fusion Approach (STDFA) to combine Huanjing satellite charge coupled device (HJ CCD), Gaofen satellite no. 1 wide field of view camera (GF-1 WFV) and Moderate Resolution Imaging Spectroradiometer (MODIS) data to generate daily high spatial resolution synthetic data for land surface process monitoring. Actual HJ CCD and GF-1 WFV data were used to evaluate the precision of the synthetic images using the correlation analysis method. Our method was tested and validated for two study areas in Xinjiang Province, China. The results show that both the ESTARFM and STDFA can be applied to combine HJ CCD and MODIS reflectance data, and GF-1 WFV and MODIS reflectance data, to generate synthetic HJ CCD data and synthetic GF-1 WFV data that closely match actual data with correlation coefficients (r) greater than 0.8989 and 0.8643, respectively. Synthetic red- and near infrared (NIR)-band data generated by ESTARFM are more suitable for the calculation of Normalized Different Vegetation Index (NDVI) than the data generated by STDFA.

  1. A Sparse Dictionary Learning-Based Adaptive Patch Inpainting Method for Thick Clouds Removal from High-Spatial Resolution Remote Sensing Imagery

    Science.gov (United States)

    Yang, Xiaomei; Zhou, Chenghu; Li, Zhi

    2017-01-01

    Cloud cover is inevitable in optical remote sensing (RS) imagery on account of the influence of observation conditions, which limits the availability of RS data. Therefore, it is of great significance to be able to reconstruct the cloud-contaminated ground information. This paper presents a sparse dictionary learning-based image inpainting method for adaptively recovering the missing information corrupted by thick clouds patch-by-patch. A feature dictionary was learned from exemplars in the cloud-free regions, which was later utilized to infer the missing patches via sparse representation. To maintain the coherence of structures, structure sparsity was brought in to encourage first filling-in of missing patches on image structures. The optimization model of patch inpainting was formulated under the adaptive neighborhood-consistency constraint, which was solved by a modified orthogonal matching pursuit (OMP) algorithm. In light of these ideas, the thick-cloud removal scheme was designed and applied to images with simulated and true clouds. Comparisons and experiments show that our method can not only keep structures and textures consistent with the surrounding ground information, but also yield rare smoothing effect and block effect, which is more suitable for the removal of clouds from high-spatial resolution RS imagery with salient structures and abundant textured features. PMID:28914787

  2. A Sparse Dictionary Learning-Based Adaptive Patch Inpainting Method for Thick Clouds Removal from High-Spatial Resolution Remote Sensing Imagery.

    Science.gov (United States)

    Meng, Fan; Yang, Xiaomei; Zhou, Chenghu; Li, Zhi

    2017-09-15

    Cloud cover is inevitable in optical remote sensing (RS) imagery on account of the influence of observation conditions, which limits the availability of RS data. Therefore, it is of great significance to be able to reconstruct the cloud-contaminated ground information. This paper presents a sparse dictionary learning-based image inpainting method for adaptively recovering the missing information corrupted by thick clouds patch-by-patch. A feature dictionary was learned from exemplars in the cloud-free regions, which was later utilized to infer the missing patches via sparse representation. To maintain the coherence of structures, structure sparsity was brought in to encourage first filling-in of missing patches on image structures. The optimization model of patch inpainting was formulated under the adaptive neighborhood-consistency constraint, which was solved by a modified orthogonal matching pursuit (OMP) algorithm. In light of these ideas, the thick-cloud removal scheme was designed and applied to images with simulated and true clouds. Comparisons and experiments show that our method can not only keep structures and textures consistent with the surrounding ground information, but also yield rare smoothing effect and block effect, which is more suitable for the removal of clouds from high-spatial resolution RS imagery with salient structures and abundant textured features.

  3. High spatial resolution time-resolved magnetic resonance angiography of lower extremity tumors at 3T: Comparison with computed tomography angiography.

    Science.gov (United States)

    Wu, Gang; Jin, Teng; Li, Ting; Morelli, John; Li, Xiaoming

    2016-09-01

    The aim of this study was to compare diagnostic value of high spatial resolution time-resolved magnetic resonance angiography with interleaved stochastic trajectory (TWIST) using Gadobutrol to Computed tomography angiography (CTA) for preoperative evaluation of lower extremity tumors.This prospective study was approved by the institutional review board. Fifty consecutive patients (31 men, 19 women, age range 18-80 years, average age 42.7 years) with lower extremity tumors underwent TWIST magnetic resonance angiography (MRA) and CTA. Digital subtraction angiography was available for 8 patients. Image quality of MRA was compared with CTA by 2 radiologists according to a 4-point Likert scale. Arterial involvement by tumor was compared using kappa test between MRA and CTA. The ability to identify feeding arteries and arterio-venous fistulae (AVF) was compared using Wilcoxon signed rank test and McNemar test, respectively.Image quality of MRA and CTA was rated without a statistically significant difference (3.88 ± 0.37 vs. 3.97 ± 0.16, P = 0.135). Intramodality agreement was high for the identification of arterial invasion (kappa = 0.806 ± 0.073 for Reader 1, kappa = 0.805 ± 0.073 for Reader 2). Readers found AVF in 27 of 50 MRA cases and 14 of 50 CTA cases (P < 0.001). Mean feeding arteries identified with MRA were significantly more than that with CTA (2.08 ± 1.72 vs. 1.62 ± 1.52, P = .02).TWIST MRA is a reliable imaging modality for the assessment of lower extremity tumors. TWIST MRA is comparable to CTA for the identification of AVF and feeding arteries.

  4. Clouds and Hazes in Saturn's North Polar Vortex: New Results from Cassini/VIMS High-Spatial Resolution Spectral Imagery on the First Grand Finale Pass

    Science.gov (United States)

    Baines, Kevin H.; Sromovsky, Lawrence A.; Fry, Patrick M.; Momary, Thomas W.; Brown, Robert H.; Buratti, Bonnie J.; Clark, Roger Nelson; Nicholson, Philip D.; Sotin, Christophe

    2017-10-01

    High-spatial-resolution spectral images of Saturn's polar region obtained during the first Grand Finale pass on April 26, 2017 by the Cassini/Visual Infrared Mapping Spectrometer (VIMS) reveal a variety of cloud/haze structures exhibiting distinctively different colors in the near-infrared, corresponding to a variety of cloud compositions, altitudes and thicknesses. Two spectral images in particular, obtained from altitudes of 110,000 km and 69,600 km above the cloudtops - corresponding to VIMS pixel resolutions of 55 and 34 km, some five times better than has been obtained by VIMS on any previous orbit - reveal small (~ 200 km across) discrete clouds remarkably enhanced in 3-micron absorption compared to nearby features, indicating enhanced ammonia and/or perhaps ammonia hydrosulfide or water ice absorptions. The ~2000-km-wide eye of the vortex in which these discrete ammonia/water ice clouds are embedded is surprisingly dark, exhibiting reflectivities less than one-third of those displayed by the small discrete clouds at all near-IR continuum wavelengths. However, at 5 microns, this contrast is reversed with the vortex eye emanating eight times the thermal flux of the embedded clouds. Taken together, the small reflectivity and large 5-micron thermal transmission indicate that the eye is an optically-thin haze/cloud region, nearly devoid of aerosols. From a dynamical point of view, the stark contrast between the reflectively dark, nearly-aerosol-free polar "eye" - indicative of downwelling processes - and the clouds of 3-micron absorbers embedded within it - indicative of powerful upwelling of materials from the depths of Saturn perhaps 50-200 km below - is puzzling, revealing that a remarkable range of vertical dynamical processes occur in Saturn's north polar region over relatively small spatial scales. Quantitative results for these various clouds, including their compositional characteristics, altitudes, mass loading, and wavelength-dependent opacities will be

  5. Mapping Above-Ground Biomass of Winter Oilseed Rape Using High Spatial Resolution Satellite Data at Parcel Scale under Waterlogging Conditions

    Directory of Open Access Journals (Sweden)

    Jiahui Han

    2017-03-01

    Full Text Available Oilseed rape (Brassica napus L. is one of the three most important oil crops in China, and is regarded as a drought-tolerant oilseed crop. However, it is commonly sensitive to waterlogging, which usually refers to an adverse environment that limits crop development. Moreover, crop growth and soil irrigation can be monitored at a regional level using remote sensing data. High spatial resolution optical satellite sensors are very useful to capture and resist unfavorable field conditions at the sub-field scale. In this study, four different optical sensors, i.e., Pleiades-1A, Worldview-2, Worldview-3, and SPOT-6, were used to estimate the dry above-ground biomass (AGB of oilseed rape and track the seasonal growth dynamics. In addition, three different soil water content field experiments were carried out at different oilseed rape growth stages from November 2014 to May 2015 in Northern Zhejiang province, China. As a significant indicator of crop productivity, AGB was measured during the seasonal growth stages of the oilseed rape at the experimental plots. Several representative vegetation indices (VIs obtained from multiple satellite sensors were compared with the simultaneously-collected oilseed rape AGB. Results showed that the estimation model using the normalized difference vegetation index (NDVI with a power regression model performed best through the seasonal growth dynamics, with the highest coefficient of determination (R2 = 0.77, the smallest root mean square error (RMSE = 104.64 g/m2, and the relative RMSE (rRMSE = 21%. It is concluded that the use of selected VIs and high spatial multiple satellite data can significantly estimate AGB during the winter oilseed rape growth stages, and can be applied to map the variability of winter oilseed rape at the sub-field level under different waterlogging conditions, which is very promising in the application of agricultural irrigation and precision agriculture.

  6. The role of the P3 and CNV components in voluntary and automatic temporal orienting: A high spatial-resolution ERP study.

    Science.gov (United States)

    Mento, Giovanni

    2017-12-01

    A main distinction has been proposed between voluntary and automatic mechanisms underlying temporal orienting (TO) of selective attention. Voluntary TO implies the endogenous directing of attention induced by symbolic cues. Conversely, automatic TO is exogenously instantiated by the physical properties of stimuli. A well-known example of automatic TO is sequential effects (SEs), which refer to the adjustments in participants' behavioral performance as a function of the trial-by-trial sequential distribution of the foreperiod between two stimuli. In this study a group of healthy adults underwent a cued reaction time task purposely designed to assess both voluntary and automatic TO. During the task, both post-cue and post-target event-related potentials (ERPs) were recorded by means of a high spatial resolution EEG system. In the results of the post-cue analysis, the P3a and P3b were identified as two distinct ERP markers showing distinguishable spatiotemporal features and reflecting automatic and voluntary a priori expectancy generation, respectively. The brain source reconstruction further revealed that distinct cortical circuits supported these two temporally dissociable components. Namely, the voluntary P3b was supported by a left sensorimotor network, while the automatic P3a was generated by a more distributed frontoparietal circuit. Additionally, post-cue contingent negative variation (CNV) and post-target P3 modulations were observed as common markers of voluntary and automatic expectancy implementation and response selection, although partially dissociable neural networks subserved these two mechanisms. Overall, these results provide new electrophysiological evidence suggesting that distinct neural substrates can be recruited depending on the voluntary or automatic cognitive nature of the cognitive mechanisms subserving TO. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. A co-training, mutual learning approach towards mapping snow cover from multi-temporal high-spatial resolution satellite imagery

    Science.gov (United States)

    Zhu, Liujun; Xiao, Pengfeng; Feng, Xuezhi; Zhang, Xueliang; Huang, Yinyou; Li, Chengxi

    2016-12-01

    High-spatial and -temporal resolution snow cover maps for mountain areas are needed for hydrological applications and snow hazard monitoring. The Chinese GF-1 satellite is potential to provide such information with a spatial resolution of 8 m and a revisit of 4 days. The main challenge for the extraction of multi-temporal snow cover from high-spatial resolution images is that the observed spectral signature of snow and snow-free areas is non-stationary in both spatial and temporal domains. As a result, successful extraction requires adequate labelled samples for each image, which is difficult to be achieved. To solve this problem, a semi-supervised multi-temporal classification method for snow cover extraction (MSCE) is proposed. This method extends the co-training based algorithms from single image classification to multi-temporal ones. Multi-temporal images in MSCE are treated as different descriptions of the same land surface, and consequently, each pixel has multiple sets of features. Independent classifiers are trained on each feature set using a few labelled samples, and then, they are iteratively re-trained in a mutual learning way using a great number of unlabelled samples. The main principle behind MSCE is that the multi-temporal difference of land surface in spectral space can be the source of mutual learning inspired by the co-training paradigm, providing a new strategy to deal with multi-temporal image classification. The experimental findings of multi-temporal GF-1 images confirm the effectiveness of the proposed method.

  8. Sensitivity encoding (SENSE) for high spatial resolution time-of-flight MR angiography of the intracranial arteries at 3.0 T.

    Science.gov (United States)

    Willinek, W A; Gieseke, J; von Falkenhausen, M; Born, M; Hadizadeh, D; Manka, C; Textor, H J; Schild, H H; Kuhl, C K

    2004-01-01

    1) To evaluate feasibility of sensitivity encoding (SENSE) for high spatial resolution intracranial 3D time-of-flight (TOF) MR angiography at 3.0 T using a 1024 imaging matrix and 2) to compare image quality and diagnostic yield with 3.0 T TOF MRA without SENSE. In a prospective study TOF MR angiography of the circle of Willis was performed with SENSE in 24 patients on a clinical whole body 3.0 T MR system (Intera, Philips Medical Systems, NL). In the SENSE protocol (S-MRA), a SENSE factor of 2.5 was used to shorten acquisition time and to increase the anatomic coverage (5:12 min.; 150 slices). A matrix of 832 x 572 was acquired and reconstructed to 1024 yielding a non-zerofilled voxel size of 0.30 x 0.44 x 1.00 mm(3) (0.13 mm(3)). Two readers were asked to review the images regarding the presence of vascular disease, and to rate, in consensus, the quality of the angiograms on a 5-point scale (5 = excellent through 1 = non-diagnostic). Results were compared with the results in 15 subjects who underwent intracranial TOF MRA at 3.0 T without SENSE (NS-MRA: acquisition time, 7:57 min.; 100 slices). Digital subtraction angiography (DSA) served as standard of reference in the 4/24 patients in whom vascular disease was identified. S-MRA at 3.0 T was judged to provide image quality that was adequate for diagnosis or better in 24/24. Median score of image quality of S-MRA and NS-MRA were 5 and 5, respectively. In the 4 patients with DSA correlation, a total of 8 pathologic findings (7 steno-occlusive diseases, 1 aneurysm) were correctly identified on S-MRA. The use of SENSE for intracranial TOF MRA at very high imaging matrix is feasible at 3.0 T. Compared to the imaging technique without SENSE, it allows TOF MRA with substantially reduced acquisition time, and with substantially increased anatomic coverage while maintaining image quality of NS-MRA.

  9. Detection and Segmentation of Vine Canopy in Ultra-High Spatial Resolution RGB Imagery Obtained from Unmanned Aerial Vehicle (UAV: A Case Study in a Commercial Vineyard

    Directory of Open Access Journals (Sweden)

    Carlos Poblete-Echeverría

    2017-03-01

    Full Text Available The use of Unmanned Aerial Vehicles (UAVs in viticulture permits the capture of aerial Red-Green-Blue (RGB images with an ultra-high spatial resolution. Recent studies have demonstrated that RGB images can be used to monitor spatial variability of vine biophysical parameters. However, for estimating these parameters, accurate and automated segmentation methods are required to extract relevant information from RGB images. Manual segmentation of aerial images is a laborious and time-consuming process. Traditional classification methods have shown satisfactory results in the segmentation of RGB images for diverse applications and surfaces, however, in the case of commercial vineyards, it is necessary to consider some particularities inherent to canopy size in the vertical trellis systems (VSP such as shadow effect and different soil conditions in inter-rows (mixed information of soil and weeds. Therefore, the objective of this study was to compare the performance of four classification methods (K-means, Artificial Neural Networks (ANN, Random Forest (RForest and Spectral Indices (SI to detect canopy in a vineyard trained on VSP. Six flights were carried out from post-flowering to harvest in a commercial vineyard cv. Carménère using a low-cost UAV equipped with a conventional RGB camera. The results show that the ANN and the simple SI method complemented with the Otsu method for thresholding presented the best performance for the detection of the vine canopy with high overall accuracy values for all study days. Spectral indices presented the best performance in the detection of Plant class (Vine canopy with an overall accuracy of around 0.99. However, considering the performance pixel by pixel, the Spectral indices are not able to discriminate between Soil and Shadow class. The best performance in the classification of three classes (Plant, Soil, and Shadow of vineyard RGB images, was obtained when the SI values were used as input data in trained

  10. Measurement of the absorbed dose distribution near an 192Ir intravascular brachytherapy seed using a high-spatial-resolution gel dosimetry system

    Science.gov (United States)

    Massillon-JL, G.; Minniti, R.; Mitch, M. G.; Soares, C. G.

    2012-06-01

    The absorbed dose distribution at sub-millimeter distances from the Best single 192Ir intravascular brachytherapy seed was measured using a high-spatial-resolution gel dosimetry system. Two gel phantoms from the same batch were used; one for the seed irradiation and one for calibration. Since the response of this gel is energy independent for photons between 20 and 1250 keV, the gel was calibrated using a narrowly collimated 60Co gamma-ray beam (cross-sectional area ˜1 cm2). A small format laser computed tomography scanner was used to acquire the data. The measurements were carried out with a spatial resolution of 100 µm in all dimensions. The seed was calibrated at NIST in terms of air-kerma strength. The absorbed dose rate as well as the radial dose function, gL(r), was measured for radial distances between 0.6 and 12.6 mm from the seed center. The dose rate constant was measured, yielding a value of Λ = (1.122 ± 0.032) cGy h-1 U-1, which agrees with published data within the measurement uncertainty. For distances between 0.6 and 1.5 mm, gL(r) decreases from a maximum value of 1.06 down to 1.00; between 1.5 and 6.7 mm, an enhancement is clearly observed with a maximum value around 1.24 and beyond 6.7 mm, gL(r) has an approximately constant value around 1.0, which suggests that this seed can be considered as a point source only at distances larger than 6.7 mm. This latter observation agrees with data for the same seed reported previously using Gafchromic film MD-55-2. Additionally, published Monte Carlo (MC) calculations have predicted the observed behavior of the radial dose function resulting from the absorbed dose contributions of beta particles and electrons emitted by the 192Ir seed. Nonetheless, in the enhancement region, MC underestimates the dose by approximately 20%. This work suggests that beta particles and electrons emitted from the seed make a significant contribution to the total absorbed dose delivered at distances near the seed center (less

  11. A new X-ray pinhole camera for energy dispersive X-ray fluorescence imaging with high-energy and high-spatial resolution

    Energy Technology Data Exchange (ETDEWEB)

    Romano, F.P., E-mail: romanop@lns.infn.it [IBAM, CNR, Via Biblioteca 4, 95124 Catania (Italy); INFN-LNS, Via S. Sofia 62, 95123 Catania (Italy); Altana, C. [INFN-LNS, Via S. Sofia 62, 95123 Catania (Italy); Dipartimento di Fisica e Astronomia, Università di Catania, Via S. Sofia 64, 95123 Catania (Italy); Cosentino, L.; Celona, L.; Gammino, S.; Mascali, D. [INFN-LNS, Via S. Sofia 62, 95123 Catania (Italy); Pappalardo, L. [IBAM, CNR, Via Biblioteca 4, 95124 Catania (Italy); INFN-LNS, Via S. Sofia 62, 95123 Catania (Italy); Rizzo, F. [INFN-LNS, Via S. Sofia 62, 95123 Catania (Italy); Dipartimento di Fisica e Astronomia, Università di Catania, Via S. Sofia 64, 95123 Catania (Italy)

    2013-08-01

    A new X-ray pinhole camera for the Energy Dispersive X-ray Fluorescence (ED-XRF) imaging of materials with high-energy and high-spatial resolution, was designed and developed. It consists of a back-illuminated and deep depleted CCD detector (composed of 1024 × 1024 pixels with a lateral size of 13 μm) coupled to a 70 μm laser-drilled pinhole-collimator, positioned between the sample under analysis and the CCD. The X-ray pinhole camera works in a coaxial geometry allowing a wide range of magnification values. The characteristic X-ray fluorescence is induced on the samples by irradiation with an external X-ray tube working at a maximum power of 100 W (50 kV and 2 mA operating conditions). The spectroscopic capabilities of the X-ray pinhole camera were accurately investigated. Energy response and energy calibration of the CCD detector were determined by irradiating pure target-materials emitting characteristic X-rays in the energy working-domain of the system (between 3 keV and 30 keV). Measurements were performed by using a multi-frame acquisition in single-photon counting. The characteristic X-ray spectra were obtained by an automated processing of the acquired images. The energy resolution measured at the Fe–Kα line is 157 eV. The use of the X-ray pinhole camera for the 2D resolved elemental analysis was investigated by using reference-patterns of different materials and geometries. The possibility of the elemental mapping of samples up to an area of 3 × 3 cm{sup 2} was demonstrated. Finally, the spatial resolution of the pinhole camera was measured by analyzing the profile function of a sharp-edge. The spatial resolution determined at the magnification values of 3.2 × and 0.8 × (used as testing values) is about 90 μm and 190 μm respectively. - Highlights: • We developed an X-ray pinhole camera for the 2D X-ray fluorescence imaging. • X-ray spectra are obtained by a multi-frame acquisition in single photon mode. • The energy resolution in the X

  12. Estimation of reactogenicity of preparations produced on the basis of photoinactivated live vaccines against brucellosis and tularaemia on the organismic level.2. Using the method of speckle-microscopy with high spatial resolution

    Science.gov (United States)

    Ulianova, O. V.; Uianov, S. S.; Li, Pengcheng; Luo, Qingming

    2011-04-01

    The method of speckle microscopy was adapted to estimate the reactogenicity of the prototypes of vaccine preparations against extremely dangerous infections. The theory is proposed to describe the mechanism of formation of the output signal from the super-high spatial resolution speckle microscope. The experimental studies show that bacterial suspensions, irradiated in different regimes of inactivation, do not exert negative influence on the blood microcirculations in laboratory animals.

  13. Mapping of Eelgrass (Zostera marina) at Sidney Spit, Gulf Islands National Park Reserve of Canada, Using High Spatial Resolution Remote Imagery

    Science.gov (United States)

    O'Neill, Jennifer D.

    The main goal of this thesis was to evaluate the use of high spatial remote imagery to map the location and biophysical parameters of eelgrass in marine areas around Sidney Spit, a part of the Gulf Islands National Park Reserve of Canada (GINPRC). To meet this goal, three objectives were addressed: (1) Define key spectral variables that provide optimum separation between eelgrass and its associated benthic substrates, using in situ hyperspectral measurements, and simulated IKONOS and Landsat 7ETM+ spectral response; (2) evaluate the efficacy of these key variables in classification of the high spatial resolution imagery, AISA and IKONOS, at various levels of processing, to determine the processing methodology that offers the highest eelgrass mapping accuracy; and (3) evaluate the potential of "value-added" classification of two eelgrass biophysical indicators, LAI and epiphyte type. In situ hyperspectral measurements acquired at Sidney Spit in August 2008 provided four different data sets: above water spectra, below water spectral profiles, water-corrected spectra, and pure endmember spectra. In Chapter 3, these data sets were examined with first derivative analysis to determine the unique spectral variables of eelgrass and associated benthic substrates. The most effective variables in discriminating eelgrass from all other substrates were selected using data reduction statistics: M-statistic analysis and multiple discriminant analyses (MDA). These selected spectral variables enabled eelgrass classification accuracy of 98% when separating six classes on above water data: shallow ( 3 m) eelgrass, shallow sand, deep sand, shallow green algae, and spectrally deep water. The variables were located mainly in the green wavelengths, where light penetrates to the greatest depth: the slope from 500 -- 530 nm, and the first derivatives at 566 nm, 580 nm, and 602 nm. The same data were classified with 96% accuracy after correcting for the water column, using the ratios 566

  14. High-spatial resolution SIMS U-Pb zircon dating on Malay tin granites: New insights to crustal evolution of the Malaysian Peninsula

    Science.gov (United States)

    Ng, S.; Searle, M. P.; Whitehouse, M. J.; Chung, S.; Robb, L. J.; Ghani, A. A.; Sone, M.

    2012-12-01

    The Southeast Asian tin granite province has previously been recognized as comprising three distinct granitic belt (Cobbing et al., 1986): (1) Middle Permian - Late Triassic Eastern Province with mainly subduction-related I-type granites associated with Cu-Au deposits, (2) Late Permian - Early Jurassic Main Range Province with mainly S-type granites associated with Sn-W deposits, and (3) Late Triassic - Cretaceous Western Province with mixed I- and S-type granites associated with Sn-W deposits. These ages were obtained mainly using whole rock Rb-Sr and K-Ar geochronology in the 70s and 80s, methods that are no longer considered suitable for obtaining crystallization ages of granites due to unstable behaviour of these isotopes in hydrothermal systems. During 2011 we collected over 50 samples of granites across all three zones in Northern Malaysia for U-Pb dating using high-spatial resolution precision SIMS at the Swedish Museum of Natural History. The results reveal a westward younging trend across the Malay Peninsula. The Eastern Province hornblende- and biotite-granites in Eastern Malaysia formed by subduction-related processes have ages lying between 220-285 Ma. The Main Range Province dominantly S-type granites in west and central Malaysia have ages lying between 206-226 Ma. These include dominantly biotite granites with less common tourmaline+biotite leucocratic granites related to crustal thickening processes following collision of Sibumasu with Indochina and closing of the Palaeo-Tethyan Bentong-Raub suture zone. Some enigmatic young Cretaceous zircon rim ages (c. 81-80 Ma) may indicate a young hydrothermal - metasomatic origin for some tin mineralization from both the Eastern Province (Tioman Island) and the Western province (Phuket, Thailand) (Searle et al., 2012). Granites in Malaysia cannot be simply categorized as I-, S- or A-type as most of them failed to show distinctive minerals for classification and there is considerable overlap in geochemical

  15. Fast recovery of compressed multi-contrast magnetic resonance images

    Science.gov (United States)

    Güngör, Alper; Kopanoǧlu, Emre; ćukur, Tolga; Güven, H. Emre

    2017-02-01

    In many settings, multiple Magnetic Resonance Imaging (MRI) scans are performed with different contrast characteristics at a single patient visit. Unfortunately, MRI data-acquisition is inherently slow creating a persistent need to accelerate scans. Multi-contrast reconstruction deals with the joint reconstruction of different contrasts simultaneously. Previous approaches suggest solving a regularized optimization problem using group sparsity and/or color total variation, using composite-splitting denoising and FISTA. Yet, there is significant room for improvement in existing methods regarding computation time, ease of parameter selection, and robustness in reconstructed image quality. Selection of sparsifying transformations is critical in applications of compressed sensing. Here we propose using non-convex p-norm group sparsity (with p numerical brain phantom images and SRI24 atlas data) in terms of CPU-time and image quality. We show that a non-convex group sparsity function that uses the p-norm instead of the convex counterpart accelerates convergence and improves the peak-Signal-to-Noise-Ratio (pSNR), especially for highly undersampled data.

  16. Channel planform geometry and slopes from freely available high-spatial resolution imagery and DEM fusion: Implications for channel width scalings, erosion proxies, and fluvial signatures in tectonically active landscapes

    Science.gov (United States)

    Fisher, G. Burch; Bookhagen, Bodo; Amos, Colin B.

    2013-07-01

    The rapid expansion of high-spatial resolution optical sensors and imagery over the last decade presents exceptional opportunities for quantifying visible attributes of geomorphic systems. In this study, we detail a simple, robust methodology (ChanGeom) to extract continuous channel width and centerline datasets for single-thread channels using freely available high-spatial resolution imagery currently available in Google Earth and Bing Maps. Comparisons with a global dataset of field and lidar-derived channel widths indicate minimal errors associated with the imagery and ChanGeom methodology (digital elevation models (DEMs), removes along-profile shortening and coincident increases in reach-scale channel slope. Lastly, comparisons of ASTER GDEM V2, SRTM V4.1, and lidar channel profiles extracted in moderate to high-relief regions demonstrate the inferiority of the ASTER GDEM for channel slope calculations, despite the apparent spatial resolution advantages (9 ×). The methodology presented here will facilitate new discoveries in the fluvial environment that have historically been difficult due to access and imagery resolution issues, and provide greater perspective on channel signatures and responses to a host of landscape forcings, especially in tectonically active bedrock and lower order drainage systems.

  17. 3.0 Tesla high spatial resolution contrast-enhanced magnetic resonance angiography (CE-MRA) of the pulmonary circulation: initial experience with a 32-channel phased array coil using a high relaxivity contrast agent.

    Science.gov (United States)

    Nael, Kambiz; Fenchel, Michael; Krishnam, Mayil; Finn, J Paul; Laub, Gerhard; Ruehm, Stefan G

    2007-06-01

    To evaluate the technical feasibility of high spatial resolution contrast-enhanced magnetic resonance angiography (CE-MRA) with highly accelerated parallel acquisition at 3.0 T using a 32-channel phased array coil, and a high relaxivity contrast agent. Ten adult healthy volunteers (5 men, 5 women, aged 21-66 years) underwent high spatial resolution CE-MRA of the pulmonary circulation. Imaging was performed at 3 T using a 32-channel phase array coil. After intravenous injection of 1 mL of gadobenate dimeglumine (Gd-BOPTA) at 1.5 mL/s, a timing bolus was used to measure the transit time from the arm vein to the main pulmonary artery. Subsequently following intravenous injection of 0.1 mmol/kg of Gd-BOPTA at the same rate, isotropic high spatial resolution data sets (1 x 1 x 1 mm3) CE-MRA of the entire pulmonary circulation were acquired using a fast gradient-recalled echo sequence (TR/TE 3/1.2 milliseconds, FA 18 degrees) and highly accelerated parallel acquisition (GRAPPA x 6) during a 20-second breath hold. The presence of artifact, noise, and image quality of the pulmonary arterial segments were evaluated independently by 2 radiologists. Phantom measurements were performed to assess the signal-to-noise ratio (SNR). Statistical analysis of data was performed by using Wilcoxon rank sum test and 2-sample Student t test. The interobserver variability was tested by kappa coefficient. All studies were of diagnostic quality as determined by both observers. The pulmonary arteries were routinely identified up to fifth-order branches, with definition in the diagnostic range and excellent interobserver agreement (kappa = 0.84, 95% confidence interval 0.77-0.90). Phantom measurements showed significantly lower SNR (P < 0.01) using GRAPPA (17.3 +/- 18.8) compared with measurements without parallel acquisition (58 +/- 49.4). The described 3 T CE-MRA protocol in addition to high T1 relaxivity of Gd-BOPTA provides sufficient SNR to support highly accelerated parallel acquisition

  18. SU-G-BRB-10: New Generation of High Frame-Rate and High Spatial-Resolution EPID QA System for Full-Body MLC-Based Robotic Radiosurgery

    Energy Technology Data Exchange (ETDEWEB)

    Han, B; Xing, L; Wang, L [Stanford University School of Medicine, Stanford, CA (United States)

    2016-06-15

    Purpose: To systematically investigate an ultra-high spatial-resolution amorphous silicon flat-panel electronic portal imaging device (EPID) for MLC-based full-body robotic radiosurgery geometric and dosimetric quality assurance (QA). Methods: The high frame-rate and ultra-high spatial resolution EPID is an outstanding detector for measuring profiles, MLC-shaped radiosurgery field aperture verification, and small field dosimetry. A Monte Carlo based technique with a robotic linac specific response and calibration is developed to convert a raw EPID-measured image of a radiosurgery field into water-based dose distribution. The technique is applied to measure output factors and profiles for 6MV MLC-defined radiosurgery fields with various sizes ranging from 7.6mm×7.7mm to 100mm×100.1mm and the results are compared with the radiosurgery diode scan measurements in water tank. The EPID measured field sizes and the penumbra regions are analyzed to evaluate the MLC positioning accuracy. Results: For all MLC fields, the EPID measured output factors of MLC-shaped fields are in good agreement with the diode measurements. The mean output difference between the EPID and diode measurement is 0.05±0.87%. The max difference is −1.33% for 7.6mm×7.7mm field. The MLC field size derived from the EPID measurements are in good agreement comparing to the diode scan result. For crossline field sizes, the mean difference is −0.17mm±0.14mm with a maximum of −0.35mm for the 30.8mm×30.8mm field. For inline field sizes, the mean difference is +0.08mm±0.18mm with a maximum of +0.45mm for the 100mm×100.1mm field. The high resolution EPID is able to measure the whole radiation field, without the need to align the detector center perfectly at field center as diode or ion chamber measurement. The setup time is greatly reduced so that the whole process is possible for machine and patient-specific QA. Conclusion: The high spatial-resolution EPID is proved to be an accurate and efficient

  19. High-spatial-resolution isotropic three-dimensional fast-recovery fast spin-echo magnetic resonance dacryocystography combined with topical administration of sterile saline solution

    Energy Technology Data Exchange (ETDEWEB)

    Jing, Zhang, E-mail: hbtjzj@yahoo.com.cn [Department of Radiology, Tongji Hospital, Huazhong University of Science and Technology, Wuhan 430030 (China); Lang, Chen, E-mail: langc731@yahoo.com.cn [Department of Radiology, Tongji Hospital, Huazhong University of Science and Technology, Wuhan 430030 (China); Qiu-Xia, Wang, E-mail: guaiqiuqiu1981@163.com [Department of Radiology, Tongji Hospital, Huazhong University of Science and Technology, Wuhan 430030 (China); Rong, Liu, E-mail: rongr007@yahoo.com.cn [Department of Ophthalmology, Tongji Hospital, Huazhong University of Science and Technology, Wuhan 430030 (China); Xin, Luo, E-mail: hoyoho2000@sina.com [Department of Radiology, Tongji Hospital, Huazhong University of Science and Technology, Wuhan 430030 (China); Wen-Zhen, Zhu, E-mail: zhuwenzhen@hotmail.com [Department of Radiology, Tongji Hospital, Huazhong University of Science and Technology, Wuhan 430030 (China); Li-Ming, Xia, E-mail: limingxia@tjh.tjmu.edu.cn [Department of Radiology, Tongji Hospital, Huazhong University of Science and Technology, Wuhan 430030 (China); Jian-Pin, Qi, E-mail: qijp2k01@yahoo.com [Department of Radiology, Tongji Hospital, Huazhong University of Science and Technology, Wuhan 430030 (China); He, Wang, E-mail: he.wang@ge.com [GE Healthcare, 1 Build, 2F C109, 1 Hua TuoRoad, Zhang Jiang Hi-Tech Park, Shanghai 201203 (China)

    2013-09-15

    Objective: This study aims to investigate the clinical performance of three-dimensional (3D) fast-recovery fast spin-echo (FRFSE) magnetic resonance dacryocystography (MRD) with topical administration of sterile saline solution for the assessment of the lacrimal drainage system (LDS). Methods: A total of 13 healthy volunteers underwent both 3D-FRFSE MRD and two-dimensional (2D)-impulse recovery (IR)-single-shot fast spin-echo (SSFSE) MRD after topical administration of sterile saline solution, and 31 patients affected by primary LDS outflow impairment or postsurgical recurrent epiphora underwent 3D-FRFSE MRD and conventional T1- and T2-weighted sequences. All patients underwent lacrimal endoscopy or surgery, which served as a standard of reference for confirming the MRD findings. Results: 3D-FRFSE MRD detected more visualized superior and inferior canaliculi and nasolacrimal duct than 2D-IR-SSFSE MRD. Compared with 2D-IR-SSFSE MRD, 3D-FRFSE MRD showed more visualized segments per LDS, although the difference was not statistically significant. Significant improvements in the inferior canaliculus and nasolacrimal duct visibility grades were achieved using 3D-FRFSE MRD. 3D-FRFSE MRD had 100% sensitivity and 63.6% specificity for detecting LDS obstruction. In 51 out of the 62 LDSs that were assessed, a 90% agreement was noted between the findings of 3D-FRFSE MRD and lacrimal endoscopy in detecting the obstruction level. Conclusion: 3D-FRFSE MRD combined with topical administration of sterile saline solution is a simple and noninvasive method of obtaining detailed morphological and functional information on the LDS. Overall, 3D-FRFSE MRD could be used as a reliable diagnostic method in many patients with epiphora prior to surgery.

  20. A fast screening protocol for carotid plaques imaging using 3D multi-contrast MRI without contrast agent.

    Science.gov (United States)

    Zhang, Na; Zhang, Lei; Yang, Qi; Pei, Anqi; Tong, Xiaoxin; Chung, Yiu-Cho; Liu, Xin

    2017-06-01

    To implement a fast (~15min) MRI protocol for carotid plaque screening using 3D multi-contrast MRI sequences without contrast agent on a 3Tesla MRI scanner. 7 healthy volunteers and 25 patients with clinically confirmed transient ischemic attack or suspected cerebrovascular ischemia were included in this study. The proposed protocol, including 3D T1-weighted and T2-weighted SPACE (variable-flip-angle 3D turbo spin echo), and T1-weighted magnetization prepared rapid acquisition gradient echo (MPRAGE) was performed first and was followed by 2D T1-weighted and T2-weighted turbo spin echo, and post-contrast T1-weighted SPACE sequences. Image quality, number of plaques, and vessel wall thicknesses measured at the intersection of the plaques were evaluated and compared between sequences. Average examination time of the proposed protocol was 14.6min. The average image quality scores of 3D T1-weighted, T2-weighted SPACE, and T1-weighted magnetization prepared rapid acquisition gradient echo were 3.69, 3.75, and 3.48, respectively. There was no significant difference in detecting the number of plaques and vulnerable plaques using pre-contrast 3D images with or without post-contrast T1-weighted SPACE. The 3D SPACE and 2D turbo spin echo sequences had excellent agreement (R=0.96 for T1-weighted and 0.98 for T2-weighted, pagent. Copyright © 2016. Published by Elsevier Inc.

  1. High spatial resolution probes for neurobiology applications

    Science.gov (United States)

    Gunning, D. E.; Kenney, C. J.; Litke, A. M.; Mathieson, K.

    2009-06-01

    Position-sensitive biological neural networks, such as the brain and the retina, require position-sensitive detection methods to identify, map and study their behavior. Traditionally, planar microelectrodes have been employed to record the cell's electrical activity with device limitations arising from the electrode's 2-D nature. Described here is the development and characterization of an array of electrically conductive micro-needles aimed at addressing the limitations of planar electrodes. The capability of this array to penetrate neural tissue improves the electrode-cell electrical interface and allows more complicated 3-D networks of neurons, such as those found in brain slices, to be studied. State-of-the-art semiconductor fabrication techniques were used to etch and passivate conformally the metal coat and fill high aspect ratio holes in silicon. These are subsequently transformed into needles with conductive tips. This process has enabled the fabrication of arrays of unprecedented dimensions: 61 hexagonally close-packed electrodes, ˜200 μm tall with 60 μm spacing. Electroplating the tungsten tips with platinum ensure suitable impedance values (˜600 kΩ at 1 kHz) for the recording of neuronal signals. Without compromising spatial resolution of the neuronal recordings, this array adds a new and exciting dimension to the study of biological neural networks.

  2. TU-F-17A-04: Respiratory Phase-Resolved 3D MRI with Isotropic High Spatial Resolution: Determination of the Average Breathing Motion Pattern for Abdominal Radiotherapy Planning

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Z; Pang, J; Yang, W; Yue, Y; Tuli, R; Fraass, B; Li, D; Fan, Z [Cedars-Sinai Medical Center, Los Angeles, CA (United States)

    2014-06-15

    Purpose: To develop a retrospective 4D-MRI technique (respiratory phase-resolved 3D-MRI) for providing an accurate assessment of tumor motion secondary to respiration. Methods: A 3D projection reconstruction (PR) sequence with self-gating (SG) was developed for 4D-MRI on a 3.0T MRI scanner. The respiration-induced shift of the imaging target was recorded by SG signals acquired in the superior-inferior direction every 15 radial projections (i.e. temporal resolution 98 ms). A total of 73000 radial projections obtained in 8-min were retrospectively sorted into 10 time-domain evenly distributed respiratory phases based on the SG information. Ten 3D image sets were then reconstructed offline. The technique was validated on a motion phantom (gadolinium-doped water-filled box, frequency of 10 and 18 cycles/min) and humans (4 healthy and 2 patients with liver tumors). Imaging protocol included 8-min 4D-MRI followed by 1-min 2D-realtime (498 ms/frame) MRI as a reference. Results: The multiphase 3D image sets with isotropic high spatial resolution (1.56 mm) permits flexible image reformatting and visualization. No intra-phase motion-induced blurring was observed. Comparing to 2D-realtime, 4D-MRI yielded similar motion range (phantom: 10.46 vs. 11.27 mm; healthy subject: 25.20 vs. 17.9 mm; patient: 11.38 vs. 9.30 mm), reasonable displacement difference averaged over the 10 phases (0.74mm; 3.63mm; 1.65mm), and excellent cross-correlation (0.98; 0.96; 0.94) between the two displacement series. Conclusion: Our preliminary study has demonstrated that the 4D-MRI technique can provide high-quality respiratory phase-resolved 3D images that feature: a) isotropic high spatial resolution, b) a fixed scan time of 8 minutes, c) an accurate estimate of average motion pattern, and d) minimal intra-phase motion artifact. This approach has the potential to become a viable alternative solution to assess the impact of breathing on tumor motion and determine appropriate treatment margins

  3. Multi-atlas Segmentation Enables Robust Multi-contrast MRI Spleen Segmentation for Splenomegaly.

    Science.gov (United States)

    Huo, Yuankai; Liu, Jiaqi; Xu, Zhoubing; Harrigan, Robert L; Assad, Albert; Abramson, Richard G; Landman, Bennett A

    2017-02-11

    Non-invasive spleen volume estimation is essential in detecting splenomegaly. Magnetic resonance imaging (MRI) has been used to facilitate splenomegaly diagnosis in vivo. However, achieving accurate spleen volume estimation from MR images is challenging given the great inter-subject variance of human abdomens and wide variety of clinical images/modalities. Multi-atlas segmentation has been shown to be a promising approach to handle heterogeneous data and difficult anatomical scenarios. In this paper, we propose to use multi-atlas segmentation frameworks for MRI spleen segmentation for splenomegaly. To the best of our knowledge, this is the first work that integrates multi-atlas segmentation for splenomegaly as seen on MRI. To address the particular concerns of spleen MRI, automated and novel semi-automated atlas selection approaches are introduced. The automated approach interactively selects a subset of atlases using selective and iterative method for performance level estimation (SIMPLE) approach. To further control the outliers, semi-automated craniocaudal length based SIMPLE atlas selection (L-SIMPLE) is proposed to introduce a spatial prior in a fashion to guide the iterative atlas selection. A dataset from a clinical trial containing 55 MRI volumes (28 T1 weighted and 27 T2 weighted) was used to evaluate different methods. Both automated and semi-automated methods achieved median DSC > 0.9. The outliers were alleviated by the L-SIMPLE (≈1 min manual efforts per scan), which achieved 0.9713 Pearson correlation compared with the manual segmentation. The results demonstrated that the multi-atlas segmentation is able to achieve accurate spleen segmentation from the multi-contrast splenomegaly MRI scans.

  4. Low-dose, time-resolved, contrast-enhanced 3D MR angiography in cardiac and vascular diseases: correlation to high spatial resolution 3D contrast-enhanced MRA

    Energy Technology Data Exchange (ETDEWEB)

    Krishnam, M.S. [Department of Radiological Sciences, University of California at Los Angeles, Los Angeles, CA (United States)], E-mail: mkrishnam@mednet.ucla.edu; Tomasian, A.; Lohan, D.G.; Tran, L.; Finn, J.P.; Ruehm, S.G. [Department of Radiological Sciences, University of California at Los Angeles, Los Angeles, CA (United States)

    2008-07-15

    Aim: To evaluate the effectiveness of low-dose, contrast-enhanced, time-resolved, three-dimensional (3D) magnetic resonance (MR) angiography (TR-MRA) in the assessment of various cardiac and vascular diseases, and to compare the results with high-resolution contrast-enhanced MRA (CE-MRA). Materials and Methods: Thirty consecutive patients underwent contrast-enhanced 3D TR-MRA and high spatial resolution 3D CE-MRA for evaluation of cardiac and thoracic vascular diseases at 1.5 T, and neurovascular, abdominal and peripheral vascular diseases at 3 T. Gadolinium-based contrast medium was administered at a constant dose of 5 ml for TR-MRA, and 20 ml (lower extremity 30 ml) for CE-MRA. Two readers evaluated image quality using a four-point scale (from 0 = excellent to 3 = non-diagnostic), artefacts and findings on both datasets. Interobserver variability was tested with kappa coefficient. Results: The overall image quality for TR-MRA was in the diagnostic range (median 0, range 0-1; k = 0.74). Readers demonstrated important additional dynamic information on TR-MRA in 28 of 30 patients (k = 0.84). Confident evaluation of organ perfusion (n = 23), arteriovenous malformation/fistula flow patterns (n = 7), exclusion of intra-cardiac shunts (n = 6), and assessment of stent and conduit patency (n = 5) were performed by both readers using TR-MRA. Readers demonstrated fine vascular details with higher confidence in 10 patients on CE-MRA. Using CE-MRA, Reader 1 and 2 depicted anatomical details in 6 and 5 patients, respectively, only on CE-MRA. Conclusion: Low-dose TR-MRA yields rapid and important functional and anatomical information in patients with cardiac and vascular diseases. Due to limited spatial resolution, TR-MRA is inferior to CE-MRA in demonstrating fine vascular details.

  5. Multi-contrast imaging of human posterior eye by Jones matrix optical coherence tomography

    Science.gov (United States)

    Yasuno, Yoshiaki

    2017-04-01

    A multi-contrast imaging of pathologic posterior eyes is demonstrated by Jones matrix optical coherence tomography (Jones matrix OCT). The Jones matrix OCT provides five tomographies, which includes scattering, local attenuation, birefringence, polarization uniformity, and optical coherence angiography, by a single scan. The hardware configuration, algorithms of the Jones matrix OCT as well as its application to ophthalmology is discussed.

  6. Automated Multi-Contrast Brain Pathological Area Extraction from 2D MR Images

    Czech Academy of Sciences Publication Activity Database

    Dvořák, Pavel; Bartušek, Karel; Kropatsch, W.G.; Smékal, Z.

    2015-01-01

    Roč. 13, č. 1 (2015), s. 58-69 ISSN 1665-6423 R&D Projects: GA ČR GAP102/12/1104 Institutional support: RVO:68081731 Keywords : Brain Pathology * Brain Tumor * MRI * Multi-contrast MRI * Symmetry Analysis Subject RIV: BH - Optics, Masers, Lasers Impact factor: 0.447, year: 2013

  7. Vectorial total generalized variation for accelerated multi-channel multi-contrast MRI.

    Science.gov (United States)

    Chatnuntawech, Itthi; Martin, Adrian; Bilgic, Berkin; Setsompop, Kawin; Adalsteinsson, Elfar; Schiavi, Emanuele

    2016-10-01

    To develop and implement an efficient reconstruction technique to improve accelerated multi-channel multi-contrast MRI. The vectorial total generalized variation (TGV) operator is used as a regularizer for the sensitivity encoding (SENSE) technique to improve image quality of multi-channel multi-contrast MRI. The alternating direction method of multipliers (ADMM) is used to efficiently reconstruct the data. The performance of the proposed method (MC-TGV-SENSE) is assessed on two healthy volunteers at several acceleration factors. As demonstrated on the in vivo results, MC-TGV-SENSE had the lowest root-mean-square error (RMSE), highest structural similarity index, and best visual quality at all acceleration factors, compared to other methods under consideration. MC-TGV-SENSE yielded up to 17.3% relative RMSE reduction compared to the widely used total variation regularized SENSE. Furthermore, we observed that the reconstruction time of MC-TGV-SENSE is reduced by approximately a factor of two with comparable RMSEs by using the proposed ADMM-based algorithm as opposed to the more commonly used Chambolle-Pock primal-dual algorithm for the TGV-based reconstruction. MC-TGV-SENSE is a better alternative than the existing reconstruction methods for accelerated multi-channel multi-contrast MRI. The proposed method exploits shared information among the images (MC), mitigates staircasing artifacts (TGV), and uses the encoding power of multiple receiver coils (SENSE). Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Multi-Contrast Imaging and Digital Refocusing on a Mobile Microscope with a Domed LED Array.

    Directory of Open Access Journals (Sweden)

    Zachary F Phillips

    Full Text Available We demonstrate the design and application of an add-on device for improving the diagnostic and research capabilities of CellScope--a low-cost, smartphone-based point-of-care microscope. We replace the single LED illumination of the original CellScope with a programmable domed LED array. By leveraging recent advances in computational illumination, this new device enables simultaneous multi-contrast imaging with brightfield, darkfield, and phase imaging modes. Further, we scan through illumination angles to capture lightfield datasets, which can be used to recover 3D intensity and phase images without any hardware changes. This digital refocusing procedure can be used for either 3D imaging or software-only focus correction, reducing the need for precise mechanical focusing during field experiments. All acquisition and processing is performed on the mobile phone and controlled through a smartphone application, making the computational microscope compact and portable. Using multiple samples and different objective magnifications, we demonstrate that the performance of our device is comparable to that of a commercial microscope. This unique device platform extends the field imaging capabilities of CellScope, opening up new clinical and research possibilities.

  9. Multi-Contrast Imaging and Digital Refocusing on a Mobile Microscope with a Domed LED Array.

    Science.gov (United States)

    Phillips, Zachary F; D'Ambrosio, Michael V; Tian, Lei; Rulison, Jared J; Patel, Hurshal S; Sadras, Nitin; Gande, Aditya V; Switz, Neil A; Fletcher, Daniel A; Waller, Laura

    2015-01-01

    We demonstrate the design and application of an add-on device for improving the diagnostic and research capabilities of CellScope--a low-cost, smartphone-based point-of-care microscope. We replace the single LED illumination of the original CellScope with a programmable domed LED array. By leveraging recent advances in computational illumination, this new device enables simultaneous multi-contrast imaging with brightfield, darkfield, and phase imaging modes. Further, we scan through illumination angles to capture lightfield datasets, which can be used to recover 3D intensity and phase images without any hardware changes. This digital refocusing procedure can be used for either 3D imaging or software-only focus correction, reducing the need for precise mechanical focusing during field experiments. All acquisition and processing is performed on the mobile phone and controlled through a smartphone application, making the computational microscope compact and portable. Using multiple samples and different objective magnifications, we demonstrate that the performance of our device is comparable to that of a commercial microscope. This unique device platform extends the field imaging capabilities of CellScope, opening up new clinical and research possibilities.

  10. Multi-contrast 3D X-ray imaging of porous and composite materials

    Energy Technology Data Exchange (ETDEWEB)

    Sarapata, Adrian; Herzen, Julia [Lehrstuhl für Biomedizinische Physik, Physik-Department and Institut für Medizintechnik, Technische Universität München, 85748 Garching (Germany); Ruiz-Yaniz, Maite [Lehrstuhl für Biomedizinische Physik, Physik-Department and Institut für Medizintechnik, Technische Universität München, 85748 Garching (Germany); European Synchrotron Radiation Facility, 38000 Grenoble (France); Zanette, Irene [Lehrstuhl für Biomedizinische Physik, Physik-Department and Institut für Medizintechnik, Technische Universität München, 85748 Garching (Germany); Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 0QX (United Kingdom); Rack, Alexander [European Synchrotron Radiation Facility, 38000 Grenoble (France); Pfeiffer, Franz [Lehrstuhl für Biomedizinische Physik, Physik-Department and Institut für Medizintechnik, Technische Universität München, 85748 Garching (Germany); Institut für Diagnostische und Interventionelle Radiologie, Klinikum rechts der Isar, Technische Universität München, 81675 München (Germany)

    2015-04-13

    Grating-based X-ray computed tomography allows for simultaneous and nondestructive determination of the full X-ray complex index of refraction and the scattering coefficient distribution inside an object in three dimensions. Its multi-contrast capabilities combined with a high resolution of a few micrometers make it a suitable tool for assessing multiple phases inside porous and composite materials such as concrete. Here, we present quantitative results of a proof-of-principle experiment performed on a concrete sample. Thanks to the complementarity of the contrast channels, more concrete phases could be distinguished than in conventional attenuation-based imaging. The phase-contrast reconstruction shows high contrast between the hardened cement paste and the aggregates and thus allows easy 3D segmentation. Thanks to the dark-field image, micro-cracks inside the coarse aggregates are visible. We believe that these results are extremely interesting in the field of porous and composite materials studies because of unique information provided by grating interferometry in a non-destructive way.

  11. Multi-contrast MRI registration of carotid arteries based on cross-sectional images and lumen boundaries

    Science.gov (United States)

    Wu, Yu-Xia; Zhang, Xi; Xu, Xiao-Pan; Liu, Yang; Zhang, Guo-Peng; Li, Bao-Juan; Chen, Hui-Jun; Lu, Hong-Bing

    2017-02-01

    Ischemic stroke has great correlation with carotid atherosclerosis and is mostly caused by vulnerable plaques. It's particularly important to analysis the components of plaques for the detection of vulnerable plaques. Recently plaque analysis based on multi-contrast magnetic resonance imaging has attracted great attention. Though multi-contrast MR imaging has potentials in enhanced demonstration of carotid wall, its performance is hampered by the misalignment of different imaging sequences. In this study, a coarse-to-fine registration strategy based on cross-sectional images and wall boundaries is proposed to solve the problem. It includes two steps: a rigid step using the iterative closest points to register the centerlines of carotid artery extracted from multi-contrast MR images, and a non-rigid step using the thin plate spline to register the lumen boundaries of carotid artery. In the rigid step, the centerline was extracted by tracking the crosssectional images along the vessel direction calculated by Hessian matrix. In the non-rigid step, a shape context descriptor is introduced to find corresponding points of two similar boundaries. In addition, the deterministic annealing technique is used to find a globally optimized solution. The proposed strategy was evaluated by newly developed three-dimensional, fast and high resolution multi-contrast black blood MR imaging. Quantitative validation indicated that after registration, the overlap of two boundaries from different sequences is 95%, and their mean surface distance is 0.12 mm. In conclusion, the proposed algorithm has improved the accuracy of registration effectively for further component analysis of carotid plaques.

  12. Estimating Urban Gross Primary Productivity at High Spatial Resolution

    Science.gov (United States)

    Miller, D. L.; Roberts, D. A.; McFadden, J. P.

    2016-12-01

    Gross primary productivity (GPP) is an important metric of ecosystem function and describes the rate of carbon uptake as the sum of net photosynthesis by all plants at the ecosystem scale. To quantify regional and global carbon budgets, GPP is commonly mapped at large scales using remote sensing techniques. While urban areas often have high proportions of vegetated cover, they are largely excluded from global estimates of GPP due to the challenges of small-scale heterogeneity in cover types. Here, we created a map of mid-summer GPP for the Minneapolis-Saint Paul, Minnesota metropolitan region based on in-situ carbon flux measurements and remotely sensed data. Using 2-meter multispectral imagery from the WorldView-2 satellite, we were able to distinguish vegetated from non-vegetated surfaces, reducing the level of within-pixel land cover mixing that normally would be present in coarser resolution imagery. Additional data sources for classification included canopy height from airborne lidar and land use/land cover polygons from MetroGIS. Our overall classification accuracy was 98.17% (kappa = 0.9725). We found that trees and turf grasses within our study area had similar total extents, with trees covering 28% and grass covering 24% of the total study area of 894 km2. We estimated GPP with a light use efficiency approach, using eddy covariance and sap flow measurements of GPP that were independently obtained for tree and turf grass cover types in the study area. Our preliminary results showed significant differences in GPP between the tree and turf grass cover types, as well as high spatial variability of GPP within the cover types across the study area.

  13. Quantifying mangrove chlorophyll from high spatial resolution imagery

    NARCIS (Netherlands)

    Heenkenda, M.K.; Joyce, K.E.; Maier, S.W.; Bruin, de S.

    2015-01-01

    Lower than expected chlorophyll concentration of a plant can directly limit photosynthetic activity, and resultant primary production. Low chlorophyll concentration may also indicate plant physiological stress. Compared to other terrestrial vegetation, mangrove chlorophyll variations are poorly

  14. An Architecture Offering Mobile Pollution Sensing with High Spatial Resolution

    Directory of Open Access Journals (Sweden)

    Oscar Alvear

    2016-01-01

    Full Text Available Mobile sensing is becoming the best option to monitor our environment due to its ease of use, high flexibility, and low price. In this paper, we present a mobile sensing architecture able to monitor different pollutants using low-end sensors. Although the proposed solution can be deployed everywhere, it becomes especially meaningful in crowded cities where pollution values are often high, being of great concern to both population and authorities. Our architecture is composed of three different modules: a mobile sensor for monitoring environment pollutants, an Android-based device for transferring the gathered data to a central server, and a central processing server for analyzing the pollution distribution. Moreover, we analyze different issues related to the monitoring process: (i filtering captured data to reduce the variability of consecutive measurements; (ii converting the sensor output to actual pollution levels; (iii reducing the temporal variations produced by mobile sensing process; and (iv applying interpolation techniques for creating detailed pollution maps. In addition, we study the best strategy to use mobile sensors by first determining the influence of sensor orientation on the captured values and then analyzing the influence of time and space sampling in the interpolation process.

  15. Observations of solar scattering polarization at high spatial resolution

    NARCIS (Netherlands)

    Snik, F.|info:eu-repo/dai/nl/304832154; de Wijn, A.G.; Ichimoto, K.; Fischer, C.E.|info:eu-repo/dai/nl/304833258; Keller, C.U.|info:eu-repo/dai/nl/304824550; Lites, B.W.

    2010-01-01

    Context. The weak, turbulent magnetic fields that supposedly permeate most of the solar photosphere are difficult to observe, because the Zeeman effect is virtually blind to them. The Hanle effect, acting on the scattering polarization in suitable lines, can in principle be used as a diagnostic for

  16. Trace metal imaging with high spatial resolution: Applications in biomedicine

    OpenAIRE

    Qin, Z.; Caruso, J A; B. Lai; Matusch, A.; Becker, J. S.

    2011-01-01

    New generations of analytical techniques for imaging of metals are pushing hitherto boundaries of spatial resolution and quantitative analysis in biology. Because of this, the application of these imaging techniques described herein to the study of the organization and dynamics of metal cations and metal-containing biomolecules in biological cell and tissue is becoming an important issue in biomedical research. In the current review, three common metal imaging techniques in biomedical researc...

  17. Trace metal imaging with high spatial resolution: applications in biomedicine.

    Science.gov (United States)

    Qin, Zhenyu; Caruso, Joseph A; Lai, Barry; Matusch, Andreas; Becker, J Sabine

    2011-01-01

    New generations of analytical techniques for imaging of metals are pushing hitherto boundaries of spatial resolution and quantitative analysis in biology. Because of this, the application of these imaging techniques described herein to the study of the organization and dynamics of metal cations and metal-containing biomolecules in biological cell and tissue is becoming an important issue in biomedical research. In the current review, three common metal imaging techniques in biomedical research are introduced, including synchrotron X-ray fluorescence (SXRF) microscopy, secondary ion mass spectrometry (SIMS), and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). These are exemplified by a demonstration of the dopamine-Fe complexes, by assessment of boron distribution in a boron neutron capture therapy cell model, by mapping Cu and Zn in human brain cancer and a rat brain tumor model, and by the analysis of metal topography within neuromelanin. These studies have provided solid evidence that demonstrates that the sensitivity, spatial resolution, specificity, and quantification ability of metal imaging techniques is suitable and highly desirable for biomedical research. Moreover, these novel studies on the nanometre scale (e.g., of individual single cells or cell organelles) will lead to a better understanding of metal processes in cells and tissues.

  18. A High Spatial Resolution CT Scanner for Small Animal Imaging

    Science.gov (United States)

    Cicalini, E.; Baldazzi, G.; Belcari, N.; Del Guerra, A.; Gombia, M.; Motta, A.; Panetta, D.

    2006-01-01

    We have built a micro-CT system that will be integrated with a small animal PET scanner. The components are: an X-ray source with a peak voltage of up to 60 kV, a power of 10 W and a focal spot size of 30 μm; a CCD coupled to CsI(Tl) scintillator, subdivided into 128×3072 square pixels, each with a size of 48 μm; stepping motors for the sample roto-translation; a PCI acquisition board; electronic boards to control and read-out the CCD. A program in Lab VIEW controls the data acquisition. Reconstruction algorithms have been implemented for fan-beam and cone-beam configurations. Images of a bar pattern have been acquired to evaluate the detector performance: the CTF curve has been extracted from the data, obtaining a value of 10 % at 5 lp/mm and about 3 % at 10 lp/mm. Tomographic acquisitions have been performed with a test phantom consisting of a Plexiglas cylinder, 3 cm in diameter, with holes ranging from 3 mm down to 0.6 mm in diameter, filled with different materials. The contrast resolution has been extracted from the reconstructed images: a value of 6 % (in water) for a cubic voxel size of 80 μm has been obtained.

  19. High Spatial Resolution Bidirectional Reflectance Retrieval Using Satellite Data

    Science.gov (United States)

    2010-12-01

    could be used to improve the BRDF and albedo products created by the Moderate Resolution Imaging SpectroRadiometer ( MODIS ) instrument, also onboard...Bruegge, and J. V. Martonchik, Improving MODIS surface BRDF/ Albedo retrieval with MISR multiangle observations, Geoscience and Remote Sensing, vol...19 Figure 16. Terra Spacecraft with 5 Climate-Monitoring Sensors: MODIS

  20. High Spatial Resolution shape Sensing for Adaptive Aerospace Vehicles Project

    Data.gov (United States)

    National Aeronautics and Space Administration — It is accepted that adaptive aerospace vehicles whose flight avionic systems are reconfigurable are needed to respond to changing flight parameters, vehicle system...

  1. Device for high spatial resolution chemical analysis of a sample and method of high spatial resolution chemical analysis

    Science.gov (United States)

    Van Berkel, Gary J.

    2015-10-06

    A system and method for analyzing a chemical composition of a specimen are described. The system can include at least one pin; a sampling device configured to contact a liquid with a specimen on the at least one pin to form a testing solution; and a stepper mechanism configured to move the at least one pin and the sampling device relative to one another. The system can also include an analytical instrument for determining a chemical composition of the specimen from the testing solution. In particular, the systems and methods described herein enable chemical analysis of specimens, such as tissue, to be evaluated in a manner that the spatial-resolution is limited by the size of the pins used to obtain tissue samples, not the size of the sampling device used to solubilize the samples coupled to the pins.

  2. MultiContrast Delayed Enhancement (MCODE) improves detection of subendocardial myocardial infarction by late gadolinium enhancement cardiovascular magnetic resonance: a clinical validation study.

    Science.gov (United States)

    Bandettini, W Patricia; Kellman, Peter; Mancini, Christine; Booker, Oscar Julian; Vasu, Sujethra; Leung, Steve W; Wilson, Joel R; Shanbhag, Sujata M; Chen, Marcus Y; Arai, Andrew E

    2012-11-30

    Myocardial infarction (MI) documented by late gadolinium enhancement (LGE) has clinical and prognostic importance, but its detection is sometimes compromised by poor contrast between blood and MI. MultiContrast Delayed Enhancement (MCODE) is a technique that helps discriminate subendocardial MI from blood pool by simultaneously providing a T2-weighted image with a PSIR (phase sensitive inversion recovery) LGE image. In this clinical validation study, our goal was to prospectively compare standard LGE imaging to MCODE in the detection of MI. Imaging was performed on a 1.5 T scanner on patients referred for CMR including a LGE study. Prospective comparisons between MCODE and standard PSIR LGE imaging were done by targeted, repeat imaging of slice locations. Clinical data were used to determine MI status. Images at each of multiple time points were read on separate days and categorized as to whether or not MI was present and whether an infarction was transmural or subendocardial. The extent of infarction was scored on a sector-by-sector basis. Seventy-three patients were imaged with the specified protocol. The majority were referred for vasodilator perfusion exams and viability assessment (37 ischemia assessment, 12 acute MI, 10 chronic MI, 12 other diagnoses). Forty-six patients had a final diagnosis of MI (30 subendocardial and 16 transmural). MCODE had similar specificity compared to LGE at all time points but demonstrated better sensitivity compared to LGE performed early and immediately before and after the MCODE (p = 0.008 and 0.02 respectively). Conventional LGE only missed cases of subendocardial MI. Both LGE and MCODE identified all transmural MI. Based on clinical determination of MI, MCODE had three false positive MI's; LGE had two false positive MI's including two of the three MCODE false positives. On a per sector basis, MCODE identified more infarcted sectors compared to LGE performed immediately prior to MCODE (p subendocardial MI's than LGE and

  3. MultiContrast Delayed Enhancement (MCODE improves detection of subendocardial myocardial infarction by late gadolinium enhancement cardiovascular magnetic resonance: a clinical validation study

    Directory of Open Access Journals (Sweden)

    Bandettini W Patricia

    2012-11-01

    Full Text Available Abstract Background Myocardial infarction (MI documented by late gadolinium enhancement (LGE has clinical and prognostic importance, but its detection is sometimes compromised by poor contrast between blood and MI. MultiContrast Delayed Enhancement (MCODE is a technique that helps discriminate subendocardial MI from blood pool by simultaneously providing a T2-weighted image with a PSIR (phase sensitive inversion recovery LGE image. In this clinical validation study, our goal was to prospectively compare standard LGE imaging to MCODE in the detection of MI. Methods Imaging was performed on a 1.5 T scanner on patients referred for CMR including a LGE study. Prospective comparisons between MCODE and standard PSIR LGE imaging were done by targeted, repeat imaging of slice locations. Clinical data were used to determine MI status. Images at each of multiple time points were read on separate days and categorized as to whether or not MI was present and whether an infarction was transmural or subendocardial. The extent of infarction was scored on a sector-by-sector basis. Results Seventy-three patients were imaged with the specified protocol. The majority were referred for vasodilator perfusion exams and viability assessment (37 ischemia assessment, 12 acute MI, 10 chronic MI, 12 other diagnoses. Forty-six patients had a final diagnosis of MI (30 subendocardial and 16 transmural. MCODE had similar specificity compared to LGE at all time points but demonstrated better sensitivity compared to LGE performed early and immediately before and after the MCODE (p = 0.008 and 0.02 respectively. Conventional LGE only missed cases of subendocardial MI. Both LGE and MCODE identified all transmural MI. Based on clinical determination of MI, MCODE had three false positive MI’s; LGE had two false positive MI’s including two of the three MCODE false positives. On a per sector basis, MCODE identified more infarcted sectors compared to LGE performed immediately prior

  4. Multi-contrast attenuation map synthesis for PET/MR scanners: assessment on FDG and Florbetapir PET tracers

    Energy Technology Data Exchange (ETDEWEB)

    Burgos, Ninon [University College London, Translational Imaging Group, Centre for Medical Image Computing, London (United Kingdom); Cardoso, M.J.; Modat, Marc; Ourselin, Sebastien [University College London, Translational Imaging Group, Centre for Medical Image Computing, London (United Kingdom); University College London, Dementia Research Centre, Institute of Neurology, London (United Kingdom); Thielemans, Kris; Dickson, John [University College London, Institute of Nuclear Medicine, London (United Kingdom); Schott, Jonathan M. [University College London, Dementia Research Centre, Institute of Neurology, London (United Kingdom); Atkinson, David [University College London, Centre for Medical Imaging, London (United Kingdom); Arridge, Simon R. [University College London, Centre for Medical Image Computing, London (United Kingdom); Hutton, Brian F. [University College London, Institute of Nuclear Medicine, London (United Kingdom); University of Wollongong, Centre for Medical Radiation Physics, Wollongong, NSW (Australia)

    2015-08-15

    Positron Emission Tomography/Magnetic Resonance Imaging (PET/MR) scanners are expected to offer a new range of clinical applications. Attenuation correction is an essential requirement for quantification of PET data but MRI images do not directly provide a patient-specific attenuation map. Methods We further validate and extend a Computed Tomography (CT) and attenuation map (μ-map) synthesis method based on pre-acquired MRI-CT image pairs. The validation consists of comparing the CT images synthesised with the proposed method to the original CT images. PET images were acquired using two different tracers ({sup 18}F-FDG and {sup 18}F-florbetapir). They were then reconstructed and corrected for attenuation using the synthetic μ-maps and compared to the reference PET images corrected with the CT-based μ-maps. During the validation, we observed that the CT synthesis was inaccurate in areas such as the neck and the cerebellum, and propose a refinement to mitigate these problems, as well as an extension of the method to multi-contrast MRI data. Results With the improvements proposed, a significant enhancement in CT synthesis, which results in a reduced absolute error and a decrease in the bias when reconstructing PET images, was observed. For both tracers, on average, the absolute difference between the reference PET images and the PET images corrected with the proposed method was less than 2%, with a bias inferior to 1%. Conclusion With the proposed method, attenuation information can be accurately derived from MRI images by synthesising CT using routine anatomical sequences. MRI sequences, or combination of sequences, can be used to synthesise CT images, as long as they provide sufficient anatomical information. (orig.)

  5. Wide-area mapping of resting state hemodynamic correlations at microvascular resolution with multi-contrast optical imaging (Conference Presentation)

    Science.gov (United States)

    Senarathna, Janaka; Hadjiabadi, Darian; Gil, Stacy; Thakor, Nitish V.; Pathak, Arvind P.

    2017-02-01

    Different brain regions exhibit complex information processing even at rest. Therefore, assessing temporal correlations between regions permits task-free visualization of their `resting state connectivity'. Although functional MRI (fMRI) is widely used for mapping resting state connectivity in the human brain, it is not well suited for `microvascular scale' imaging in rodents because of its limited spatial resolution. Moreover, co-registered cerebral blood flow (CBF) and total hemoglobin (HbT) data are often unavailable in conventional fMRI experiments. Therefore, we built a customized system that combines laser speckle contrast imaging (LSCI), intrinsic optical signal (IOS) imaging and fluorescence imaging (FI) to generate multi-contrast functional connectivity maps at a spatial resolution of 10 μm. This system comprised of three illumination sources: a 632 nm HeNe laser (for LSCI), a 570 nm ± 5 nm filtered white light source (for IOS), and a 473 nm blue laser (for FI), as well as a sensitive CCD camera operating at 10 frames per second for image acquisition. The acquired data enabled visualization of changes in resting state neurophysiology at microvascular spatial scales. Moreover, concurrent mapping of CBF and HbT-based temporal correlations enabled in vivo mapping of how resting brain regions were linked in terms of their hemodynamics. Additionally, we complemented this approach by exploiting the transit times of a fluorescent tracer (Dextran-FITC) to distinguish arterial from venous perfusion. Overall, we demonstrated the feasibility of wide area mapping of resting state connectivity at microvascular resolution and created a new toolbox for interrogating neurovascular function.

  6. Semi-Physical Estimates of National-Scale PM10 Concentrations in China Using a Satellite-Based Geographically Weighted Regression Model

    OpenAIRE

    Tianhao Zhang; Wei Gong; Zhongmin Zhu; Kun Sun; Yusi Huang; Yuxi Ji

    2016-01-01

    The estimation of ambient particulate matter with diameter less than 10 µm (PM10) at high spatial resolution is currently quite limited in China. In order to make the distribution of PM10 more accessible to relevant departments and scientific research institutions, a semi-physical geographically weighted regression (GWR) model was established in this study to estimate nationwide mass concentrations of PM10 using easily available MODIS AOD and NCEP Reanalysis meteorological parameters. The res...

  7. TU-CD-207-12: Impact of Anatomical Noise On Detection Performance of Microcalcifications in Multi-Contrast Breast Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Garrett, J; Ge, Y; Li, K; Chen, G [University of Wisconsin, Madison, WI (United States)

    2015-06-15

    Purpose: The anatomical noise power spectra (NPS) for differential phase contrast (DPC) and dark field (DF) imaging have recently been characterized using a power-law model with two parameters, alpha and beta, an innovative extension to the methodology used in x-ray attenuation based breast imaging such as mammography, DBT, or cone-beam CT. Beta values of 3.6, 2.6, and 1.3 have been measured for absorption, DPC, and DF respectively for cadaver breasts imaged in the coronal plane; these dramatic differences should be reflected in their detection performance. The purpose of this study was to determine the impact of anatomical noise on breast calcification detection and compare the detection performance of the three contrast mechanisms of a multi-contrast x-ray imaging system. Methods: In our studies, a calcification image object was segmented out of the multi-contrast images of a cadaver breast specimen. 50 measured total NPS were measured from breast cadavers directly. The ideal model observer detectability was calculated for a range of doses (5–100%) and a range of calcification sizes (diameter = 0.25–2.5 mm). Results: Overall we found the highest average detectability corresponded to DPC imaging (7.4 for 1 mm calc.), with DF the next highest (3.8 for 1 mm calc.), and absorption the lowest (3.2 for 1 mm calc.). However, absorption imaging also showed the slowest dependence on dose of the three modalities due to the significant anatomical noise. DPC showed a peak detectability for calcifications ∼1.25 mm in diameter, DF showed a peak for calcifications around 0.75 mm in diameter, and absorption imaging had no such peak in the range explored. Conclusion: Understanding imaging performance for DPC and DF is critical to transition these modalities to the clinic. The results presented here offer new insight into how these modalities complement absorption imaging to maximize the likelihood of detecting early breast cancers. J. Garrett, Y. Ge, K. Li: Nothing to

  8. INTRACELLULAR CHEMICAL MEASUREMENTS:A GENERALIZED APPROACH WITH HIGH-SPATIAL RESOLUTION USING FUNCTIONALIZED NANOPARTICLES

    Energy Technology Data Exchange (ETDEWEB)

    Laurence, T

    2007-03-05

    We are developing an alternative approach to optical probes that will ultimately allow us to measure chemical concentrations in microenvironments within cells and tissues. This approach is based on monitoring the surface-enhanced Raman scattering (SERS) response of functionalized metal nanoparticles (50-100 nm in diameter). SERS allows for the sensitive detection of changes in the state of chemical groups attached to individual nanoparticles and small clusters. We present the development of a nanoscale pH meter. The pH response of these nanoprobes is tested in a cell-free medium, measuring the pH of the solution immediately surrounding the nanoparticles. We developed and used SERS correlation spectroscopy and single particle/cluster SERS spectroscopy to characterize heterogeneities in the SERS signal, which result from the formation of small nanoparticle clusters. These heterogeneities have historically provided inconsistent response to pH, leading a poor sensitivity of {approx}1 pH unit. The response of the nanoscale pH meters is tested under a wide range of conditions to approach the complex environment encountered inside living cells and to optimize probe performance. We have also developed a rapid scanning technique to obtain pH information using confocal microscopic imaging. Together with the development of hollow gold nanoshells with collaborators, this project enables future cell-based studies of pH using SERS. This research will be continued as a collaboration with the Center for Biophotonics Science and Technology (CBST) at UC Davis Medical Center.

  9. X-ray phase-contrast tomography for high-spatial-resolution zebrafish muscle imaging

    Science.gov (United States)

    Vågberg, William; Larsson, Daniel H.; Li, Mei; Arner, Anders; Hertz, Hans M.

    2015-11-01

    Imaging of muscular structure with cellular or subcellular detail in whole-body animal models is of key importance for understanding muscular disease and assessing interventions. Classical histological methods for high-resolution imaging methods require excision, fixation and staining. Here we show that the three-dimensional muscular structure of unstained whole zebrafish can be imaged with sub-5 μm detail with X-ray phase-contrast tomography. Our method relies on a laboratory propagation-based phase-contrast system tailored for detection of low-contrast 4-6 μm subcellular myofibrils. The method is demonstrated on 20 days post fertilization zebrafish larvae and comparative histology confirms that we resolve individual myofibrils in the whole-body animal. X-ray imaging of healthy zebrafish show the expected structured muscle pattern while specimen with a dystrophin deficiency (sapje) displays an unstructured pattern, typical of Duchenne muscular dystrophy. The method opens up for whole-body imaging with sub-cellular detail also of other types of soft tissue and in different animal models.

  10. Laser Beam Filtration for High Spatial Resolution MALDI Imaging Mass Spectrometry

    Science.gov (United States)

    Zavalin, Andre; Yang, Junhai; Caprioli, Richard

    2013-07-01

    We describe an easy and inexpensive way to provide a highly defined Gaussian shaped laser spot on target of 5 μm diameter for imaging mass spectrometry using a commercial MALDI TOF instrument that is designed to produce a 20 μm diameter laser beam on target at its lowest setting. A 25 μm pinhole filter on a swivel arm was installed in the laser beam optics outside the vacuum ion source chamber so it is easily flipped into or out of the beam as desired by the operator. The resulting ion images at 5 μm spatial resolution are sharp since the satellite secondary laser beam maxima have been removed by the filter. Ion images are shown to demonstrate the performance and are compared with the method of oversampling to achieve higher spatial resolution when only a larger laser beam spot on target is available.

  11. Implementation of a Gaussian Beam Laser and Aspheric Optics for High Spatial Resolution MALDI Imaging MS

    Science.gov (United States)

    Zavalin, Andre; Yang, Junhai; Haase, Andreas; Holle, Armin; Caprioli, Richard

    2014-06-01

    We have investigated the use of a Gaussian beam laser for MALDI Imaging Mass Spectrometry to provide a precisely defined laser spot of 5 μm diameter on target using a commercial MALDI TOF instrument originally designed to produce a 20 μm diameter laser beam spot at its smallest setting. A Gaussian beam laser was installed in the instrument in combination with an aspheric focusing lens. This ion source produced sharp ion images at 5 μm spatial resolution with signals of high intensity as shown for images from thin tissue sections of mouse brain.

  12. High Spatial Resolution Studies of Epithermal Neutron Emission from the Lunar Poles: Constraints on Hydrogen Mobility

    Science.gov (United States)

    Boynton, W. V.; Droege, G. F.; Mitrofanov, I. G.; McClanahan, T. P.; Sanin, A. B.; Litvak, M. L.; Schaffner, M.; Chin, G.; Evans, L. G.; Garvin, J. B.; hide

    2012-01-01

    The data from the collimated sensors of the LEND instrument are shown to be of exceptionally high quality. Counting uncertainties are about 0.3% relative and are shown to be the only significant source of random error, thus conclusions based on small differences in count rates are valid. By comparison with the topography of Shoemaker crater, the spatial resolution of the instrument is shown to be consistent with the design value of 5 km for the radius of the circle over which half the counts from the lunar surface would be determined. The observed epithermal-neutron suppression factor due to the hydrogen deposit in Shoemaker crater of 0.25 plus or minus 0.04 cps is consistent with the collimated field-of-view rate of 1.7 cps estimated by Mitrofanov et al. (2010a). The statistical significance of the neutron suppressed regions (NSRs) relative to the larger surrounding polar region is demonstrated, and it is shown that they are not closely related to the permanently shadowed regions. There is a significant increase in H content in the polar regions independent of the H content of the NSRs. The non-NSR H content increases directly with latitude, and the rate of increase is virtually identical at both poles. There is little or no increase with latitude outside the polar region. Various mechanisms to explain this steep increase in the non-NSR polar H with latitude are investigated, and it is suggested that thermal volatilization is responsible for the increase because it is minimized at the low surface temperatures close to the poles.

  13. High spatial resolution spectral unmixing for mapping ash species across a complex urban environment

    Science.gov (United States)

    Jennifer Pontius; Ryan P. Hanavan; Richard A. Hallett; Bruce D. Cook; Lawrence A. Corp

    2017-01-01

    Ash (Fraxinus L.) species are currently threatened by the emerald ash borer (EAB; Agrilus planipennis Fairmaire) across a growing area in the eastern US. Accurate mapping of ash species is required to monitor the host resource, predict EAB spread and better understand the short- and long-term effects of EAB on the ash resource...

  14. Evaluation of Sun Glint Correction Algorithms for High-Spatial Resolution Hyperspectral Imagery

    Science.gov (United States)

    2012-09-01

    Surface Derived from Sun Glitter." Journal of Marine Research, 1954, 13: 198–227. Feynman , Richard P. QED: The Strange Theory of Light and Matter... Richards and Jia 2006). For example, an 8-bit image has pixel values between 0 and 255, where 0 is black and 255 is white, with shades of grey...using both the index of refraction and the angle of incidence of light upon the medium ( Feynman 1985). Light can be scattered off the surface of a

  15. Structural health monitoring by using fiber-optic distributed strain sensors with high spatial resolution

    Science.gov (United States)

    Murayama, Hideaki; Wada, Daichi; Igawa, Hirotaka

    2013-12-01

    In this paper, we review our researches on the topics of the structural health monitoring (SHM) with the fiber-optic distributed strain sensor. Highly-dense information on strains in a structure can be useful to identify some kind of existing damages or applied loads in implementation of SHM. The fiber-optic distributed sensors developed by the authors have been applied to the damage detection of a single-lap joint and load identification of a beam simply supported. We confirmed that the applicability of the distributed sensor to SHM could be improved as making the spatial resolution higher. In addition, we showed that the simulation technique considering both structural and optical effects seamlessly in strain measurement could be powerful tools to evaluate the performance of a sensing system and design it for SHM. Finally, the technique for simultaneous distributed strain and temperature measurement using the PANDA-fiber Bragg grating (FBG) is shown in this paper, because problems caused by the cross-sensitivity toward strain and temperature would be always inevitable in strain measurement for SHM.

  16. Reversible cryo-arrest for imaging molecules in living cells at high spatial resolution

    Science.gov (United States)

    Sabet, Ola; Wehner, Frank; Konitsiotis, Antonios; Fuhr, Günther R.; Bastiaens, Philippe I. H.

    2016-01-01

    The dynamics of molecules in living cells hamper precise imaging of molecular patterns by functional and super resolution microscopy. Circumventing lethal chemical fixation, an on-stage cryo-arrest was developed for consecutive imaging of molecular patterns within the same living, but arrested cells. The reversibility of consecutive cryo-arrests was demonstrated by the high survival rate of different cell lines and intact growth factor signaling that was not perturbed by stress response. Reversible cryo-arrest was applied to study the evolution of ligand-induced receptor tyrosine kinase activation at different scales. The nanoscale clustering of epidermal growth factor receptor (EGFR) in the plasma membrane was assessed by single molecule localization microscopy and endosomal microscale activity patterns of ephrin receptor type-A (EphA2) by fluorescence lifetime imaging microscopy. We thereby demonstrate that reversible cryo-arrest allows the precise determination of molecular patterns while conserving the dynamic capabilities of living cells. PMID:27400419

  17. Derivation of High Spatial Resolution Albedo from UAV Digital Imagery: Application over the Greenland Ice Sheet

    Directory of Open Access Journals (Sweden)

    Jonathan C. Ryan

    2017-05-01

    Full Text Available Measurements of albedo are a prerequisite for modeling surface melt across the Earth's cryosphere, yet available satellite products are limited in spatial and/or temporal resolution. Here, we present a practical methodology to obtain centimeter resolution albedo products with accuracies of ±5% using consumer-grade digital camera and unmanned aerial vehicle (UAV technologies. Our method comprises a workflow for processing, correcting and calibrating raw digital images using a white reference target, and upward and downward shortwave radiation measurements from broadband silicon pyranometers. We demonstrate the method with a set of UAV sorties over the western, K-sector of the Greenland Ice Sheet. The resulting albedo product, UAV10A1, covers 280 km2, at a resolution of 20 cm per pixel and has a root-mean-square difference of 3.7% compared to MOD10A1 and 4.9% compared to ground-based broadband pyranometer measurements. By continuously measuring downward solar irradiance, the technique overcomes previous limitations due to variable illumination conditions during and between surveys over glaciated terrain. The current miniaturization of multispectral sensors and incorporation of upward facing radiation sensors on UAV packages means that this technique could become increasingly common in field studies and used for a wide range of applications. These include the mapping of debris, dust, cryoconite and bioalbedo, and directly constraining surface energy balance models.

  18. High Spatial Resolution Europa Coverage by the Galileo Near Infrared Mapping Spectrometer (NIMS)

    Science.gov (United States)

    1997-01-01

    The NIMS instrument on the Galileo spacecraft, which is being used to map the mineral and ice properties over the surfaces of the Jovian moons, produces global spectral images at modest spatial resolution and high resolution spectral images for small selected regions on the satellites. This map illustrates the high resolution coverage of Europa obtained by NIMS through the April 1997 G7 orbit.The areas covered are displayed on a Voyager-derived map. A good sampling of the dark trailing-side material (180 to 360 degrees) has been obtained, with less coverage of Europa's leading side.The false-color composites use red, green and blue to represent the infrared brightnesses at 0.7, 1.51 and 1.82 microns respectively. Considerable variations are evident and are related to the composition and sizes of the surface grains.The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC.The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC.This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov.

  19. Brightness of Solar Magnetic Elements As a Function of Magnetic Flux at High Spatial Resolution

    Science.gov (United States)

    Kahil, F.; Riethmüller, T. L.; Solanki, S. K.

    2017-03-01

    We investigate the relationship between the photospheric magnetic field of small-scale magnetic elements in the quiet-Sun (QS) at disk center and the brightness at 214, 300, 313, 388, 397, and 525.02 nm. To this end, we analyzed spectropolarimetric and imaging time series acquired simultaneously by the Imaging Magnetograph eXperiment magnetograph and the SuFI filter imager on board the balloon-borne observatory {{S}}{{UNRISE}} during its first science flight in 2009, with high spatial and temporal resolution. We find a clear dependence of the contrast in the near ultraviolet and the visible on the line-of-sight component of the magnetic field, B LOS, which is best described by a logarithmic model. This function effectively represents the relationship between the Ca ii H-line emission and B LOS and works better than the power-law fit adopted by previous studies. This, along with the high contrast reached at these wavelengths, will help with determining the contribution of small-scale elements in the QS to the irradiance changes for wavelengths below 388 nm. At all wavelengths, including the continuum at 525.40 nm, the intensity contrast does not decrease with increasing B LOS. This result also strongly supports the fact that {{S}}{{UNRISE}} has resolved small strong magnetic field elements in the internetwork, resulting in constant contrasts for large magnetic fields in our continuum contrast at 525.40 nm versus the B LOS scatterplot, unlike the turnover obtained in previous observational studies. This turnover is due to the intermixing of the bright magnetic features with the dark intergranular lanes surrounding them.

  20. Quantifying the erosion effect on current carbon budget of European agricultural soils at high spatial resolution.

    Science.gov (United States)

    Lugato, Emanuele; Paustian, Keith; Panagos, Panos; Jones, Arwyn; Borrelli, Pasquale

    2016-05-01

    The idea of offsetting anthropogenic CO2 emissions by increasing global soil organic carbon (SOC), as recently proposed by French authorities ahead of COP21 in the 'four per mil' initiative, is notable. However, a high uncertainty still exits on land C balance components. In particular, the role of erosion in the global C cycle is not totally disentangled, leading to disagreement whether this process induces lands to be a source or sink of CO2. To investigate this issue, we coupled soil erosion into a biogeochemistry model, running at 1 km(2) resolution across the agricultural soils of the European Union (EU). Based on data-driven assumptions, the simulation took into account also soil deposition within grid cells and the potential C export to riverine systems, in a way to be conservative in a mass balance. We estimated that 143 of 187 Mha have C erosion rates 0.45 Mg C ha(-1) yr(-1). In comparison with a baseline without erosion, the model suggested an erosion-induced sink of atmospheric C consistent with previous empirical-based studies. Integrating all C fluxes for the EU agricultural soils, we estimated a net C loss or gain of -2.28 and +0.79 Tg yr(-1) of CO2 eq, respectively, depending on the value for the short-term enhancement of soil C mineralization due to soil disruption and displacement/transport with erosion. We concluded that erosion fluxes were in the same order of current carbon gains from improved management. Even if erosion could potentially induce a sink for atmospheric CO2, strong agricultural policies are needed to prevent or reduce soil erosion, in order to maintain soil health and productivity. © 2015 The Authors. Global Change Biology Published by John Wiley & Sons Ltd.

  1. A new silicon drift detector for high spatial resolution STEM-XEDS: performance and applications.

    Science.gov (United States)

    Phillips, Patrick J; Paulauskas, Tadas; Rowlands, Neil; Nicholls, Alan W; Low, Ke-Bin; Bhadare, Santokh; Klie, Robert F

    2014-08-01

    A newly designed, 100 mm2, silicon drift detector has been installed on an aberration-corrected scanning transmission electron microscope equipped with an ultra-high resolution pole piece, without requiring column modifications. With its unique, windowless design, the detector's active region is in close proximity to the sample, resulting in a dramatic increase in count rate, while demonstrating an increased sensitivity to low energy X-rays and a muted tilt dependence. Numerous examples of X-ray energy dispersive spectrometry are presented on relevant materials such as Al x Ga1-x N nanowires, perovskite oxides, and polycrystalline CdTe thin films, across both varying length scales and accelerating voltages.

  2. Ash Decline Assessment in Emerald Ash Borer Infested Natural Forests Using High Spatial Resolution Images

    Directory of Open Access Journals (Sweden)

    Justin Murfitt

    2016-03-01

    Full Text Available The invasive emerald ash borer (EAB, Agrilus planipennis Fairmaire infects and eventually kills endemic ash trees and is currently spreading across the Great Lakes region of North America. The need for early detection of EAB infestation is critical to managing the spread of this pest. Using WorldView-2 (WV2 imagery, the goal of this study was to establish a remote sensing-based method for mapping ash trees undergoing various infestation stages. Based on field data collected in Southeastern Ontario, Canada, an ash health score with an interval scale ranging from 0 to 10 was established and further related to multiple spectral indices. The WV2 image was segmented using multi-band watershed and multiresolution algorithms to identify individual tree crowns, with watershed achieving higher segmentation accuracy. Ash trees were classified using the random forest classifier, resulting in a user’s accuracy of 67.6% and a producer’s accuracy of 71.4% when watershed segmentation was utilized. The best ash health score-spectral index model was then applied to the ash tree crowns to map the ash health for the entire area. The ash health prediction map, with an overall accuracy of 70%, suggests that remote sensing has potential to provide a semi-automated and large-scale monitoring of EAB infestation.

  3. Forest inventory stand height estimates from very high spatial resolution satellite imagery calibrated with lidar plots

    NARCIS (Netherlands)

    Mora, B.; Wulder, M.A.; Hobart, G.W.; White, J.C.; Bater, C.W.; Gougeon, F.A.; Varhola, A.; Coops, N.C.

    2013-01-01

    Many areas of forest across northern Canada are challenging to monitor on a regular basis as a result of their large extent and remoteness. Although no forest inventory data typically exist for these northern areas, detailed and timely forest information for these areas is required to support

  4. Development and Studies of Novel Microfabricated Radiation Hard Scintillation Detectors With High Spatial Resolution

    CERN Document Server

    Mapelli, A; Haguenauer, M; Jiguet, S; Renaud, P; Vico Triviño, N

    2011-01-01

    A new type of scintillation detector is being developed with standard microfabrication techniques. It consists of a dense array of scintillating waveguides obtained by coupling microfluidic channels filled with a liquid scintillator to photodetectors. Easy manipulation of liquid scintillators inside microfluidic devices allow their flushing, renewal, and exchange making the active medium intrinsically radiation hard. Prototype detectors have been fabricated by photostructuration of a radiation hard epoxy resin (SU-8) deposited on silicon wafers and coupled to a multi-anode photomultiplier tube (MAPMT) to read-out the scintillation light. They have been characterized by exciting the liquid scintillator in the 200 micrometers thick microchannels with electrons from a 90Sr yielding approximately 1 photoelectron per impinging Minimum Ionizing Particle (MIP). These promising results demonstrate the concept of microfluidic scintillating detection and are very encouraging for future developments.

  5. High spatial resolution quantitative MR images: an experimental study of dedicated surface coils

    Energy Technology Data Exchange (ETDEWEB)

    Gensanne, D [Laboratoire de Chimie Bioinorganique Medicale, Imagerie therapeutique et diagnostique, JE 2400-CNRS FR 2599, Universite Paul Sabatier, 118, route de Narbonne, 31062 Toulouse Cedex (France); Josse, G [Centre Europeen de Recherche et d' Evaluation sur la Peau et les Epitheliums de Revetement, Institut de Recherche Pierre Fabre, 2, rue Viguerie, BP 3071 31025 Toulouse Cedex 3 (France); Lagarde, J M [Centre Europeen de Recherche et d' Evaluation sur la Peau et les Epitheliums de Revetement, Institut de Recherche Pierre Fabre, 2, rue Viguerie, BP 3071 31025 Toulouse Cedex 3 (France); Vincensini, D [Laboratoire de Chimie Bioinorganique Medicale, Imagerie therapeutique et diagnostique, JE 2400-CNRS FR 2599, Universite Paul Sabatier, 118, route de Narbonne, 31062 Toulouse Cedex (France)

    2006-06-07

    Measuring spin-spin relaxation times (T{sub 2}) by quantitative MR imaging represents a potentially efficient tool to evaluate the physicochemical properties of various media. However, noise in MR images is responsible for uncertainties in the determination of T{sub 2} relaxation times, which limits the accuracy of parametric tissue analysis. The required signal-to-noise ratio (SNR) depends on the T{sub 2} relaxation behaviour specific to each tissue. Thus, we have previously shown that keeping the uncertainty in T{sub 2} measurements within a limit of 10% implies that SNR values be greater than 100 and 300 for mono- and biexponential T{sub 2} relaxation behaviours, respectively. Noise reduction can be obtained either by increasing the voxel size (i.e., at the expense of spatial resolution) or by using high sensitivity dedicated surface coils (which allows us to increase SNR without deteriorating spatial resolution in an excessive manner). However, surface coil sensitivity is heterogeneous, i.e., it- and hence SNR-decreases with increasing depth, and the more so as the coil radius is smaller. The use of surface coils is therefore limited to the analysis of superficial structure such as the hypodermic tissue analysed here. The aim of this work was to determine the maximum limits of spatial resolution and depth compatible with reliable in vivo T{sub 2} quantitative MR images using dedicated surface coils available on various clinical MR scanners. The average thickness of adipose tissue is around 15 mm, and the results obtained have shown that obtaining reliable biexponential relaxation analysis requires a minimum achievable voxel size of 13 mm{sup 3} for a conventional volume birdcage coil and only of 1.7 mm{sup 3} for the smallest available surface coil (23 mm in diameter). Further improvement in spatial resolution allowing us to detect low details in MR images without deteriorating parametric T{sub 2} images can be obtained by image filtering. By using the non-linear selective blurring filter described in a previous work, the voxel size was reduced to 0.8 mm{sup 3}, allowing us to detect microstructures such as fibrous septae while preserving precision in T{sub 2} measurements. This paper provides practical information allowing us to perform reliable T{sub 2} quantitative MR micro images. High resolution imaging with dedicated surface coils, which is only well-suited to near surface organs, might lead to highly valuable results in this context, especially to analyse the hypodermis involved in the lipodystrophy seen in patients with human immuno-deficiency virus (HIV)

  6. Nanogap based graphene coated AFM tips with high spatial resolution, conductivity and durability.

    Science.gov (United States)

    Lanza, Mario; Gao, Teng; Yin, Zixuan; Zhang, Yanfeng; Liu, Zhongfan; Tong, Yuzhen; Shen, Ziyong; Duan, Huiling

    2013-11-21

    After one decade of analyzing the intrinsic properties of graphene, interest into the development of graphene-based devices and micro electromechanical systems is increasing. Here, we fabricate graphene-coated atomic force microscope tips by growing the graphene on copper foil and transferring it onto the apex of a commercially available AFM tip. The resulting tip exhibits surprising enhanced resolution in nanoscale electrical measurements. By means of topographic AFM maps and statistical analyses we determine that this superior performance may be related to the presence of a nanogap between the graphene and the tip apex, which reduces the tip radius and tip-sample contact area. In addition, the graphene-coated tips show a low tip-sample interaction, high conductivity and long life times. The novel fabrication-friendly tip could improve the quality and reliability of AFM experiments, while reducing the cost of AFM-based research.

  7. Prototyping and Testing a Wireless Sensor Network to Retrieve SWE at High Spatial Resolution

    Science.gov (United States)

    Kang, D.; Barros, A. P.

    2007-12-01

    A critical challenge in snow research from space is the ability to obtain measurements at the spatial and temporal resolution to characterize the statistical structure of the space-time variability of the physical properties of the snowpack within an area consistent with the pixel resolution in snow hydrology models or that expected from a future NASA mission dedicated to cold region processes. That is, observations of relevant snow dielectric properties are necessary at high spatial and temporal resolution during the accumulation and melt seasons. We present a new wireless sensor network prototype consisting of multiple antennas and buried low-power, multi- channel transmitters operating in L-band that communicate to a central pod equipped with a Vector Signal Analyzer (VSA) that receives, processes and manages the data. Only commercial off-the-shelf hard-ware parts were used to build the sensors. Because the sensors are very low cost and run autonomously, one envisions that self-organizing networks of large numbers of such sensors might be distributed over very large areas, therefore proving much needed data sets for scaling studies. The measurement strategy consists of placing the transmitters the land surface in the beginning of the snow season which are then run autonomously till the end of the spring and waken at pre-determined time-intervals to emit radio frequency signals and thus sample the snowpack. Along with the sensors, an important component of this work entails the development of an estimation algorithm to estimate snow dielectric properties, snow density, and volume fraction of snow (VF) from the time-of-travel, amplitude and phase modification of the multi-channel RF signals as they propagate through the snow-pack. Here, we present results from full system testing and evaluation of the sensors that were conducted at Duke University using ¢®¡Æsynthetic¢®¡¾ limited-area snowpacks (0.5 by 0.5 m2 and 1 by 2 m2) constructed of various combinations of foam layers of different porosities to simulate heterogeneous distributions of water. The existing sensors are currently being primed for field deployment. Discussion is also presented regarding further technology development including power usage, networking, and distribution and operations in remote regions.

  8. Numerical modeling of permafrost dynamics in Alaska using a high spatial resolution dataset

    Directory of Open Access Journals (Sweden)

    E. E. Jafarov

    2012-06-01

    Full Text Available Climate projections for the 21st century indicate that there could be a pronounced warming and permafrost degradation in the Arctic and sub-Arctic regions. Climate warming is likely to cause permafrost thawing with subsequent effects on surface albedo, hydrology, soil organic matter storage and greenhouse gas emissions.

    To assess possible changes in the permafrost thermal state and active layer thickness, we implemented the GIPL2-MPI transient numerical model for the entire Alaska permafrost domain. The model input parameters are spatial datasets of mean monthly air temperature and precipitation, prescribed thermal properties of the multilayered soil column, and water content that are specific for each soil class and geographical location. As a climate forcing, we used the composite of five IPCC Global Circulation Models that has been downscaled to 2 by 2 km spatial resolution by Scenarios Network for Alaska Planning (SNAP group.

    In this paper, we present the modeling results based on input of a five-model composite with A1B carbon emission scenario. The model has been calibrated according to the annual borehole temperature measurements for the State of Alaska. We also performed more detailed calibration for fifteen shallow borehole stations where high quality data are available on daily basis. To validate the model performance, we compared simulated active layer thicknesses with observed data from Circumpolar Active Layer Monitoring (CALM stations. The calibrated model was used to address possible ground temperature changes for the 21st century. The model simulation results show widespread permafrost degradation in Alaska could begin between 2040–2099 within the vast area southward from the Brooks Range, except for the high altitude regions of the Alaska Range and Wrangell Mountains.

  9. Mapping Aquatic Vegetation in a Tropical Wetland Using High Spatial Resolution Multispectral Satellite Imagery

    Directory of Open Access Journals (Sweden)

    Timothy G. Whiteside

    2015-09-01

    Full Text Available Vegetation plays a key role in the environmental function of wetlands. The Ramsar-listed wetlands of the Magela Creek floodplain in Northern Australia are identified as being at risk from weeds, fire and climate change. In addition, the floodplain is a downstream receiving environment for the Ranger Uranium Mine. Accurate methods for mapping wetland vegetation are required to provide contemporary baselines of annual vegetation dynamics on the floodplain to assist with analysing any potential change during and after minesite rehabilitation. The aim of this study was to develop and test the applicability of geographic object-based image analysis including decision tree classification to classify WorldView-2 imagery and LiDAR-derived ancillary data to map the aquatic vegetation communities of the Magela Creek floodplain. Results of the decision tree classification were compared against a Random Forests classification. The resulting maps showed the 12 major vegetation communities that exist on the Magela Creek floodplain and their distribution for May 2010. The decision tree classification method provided an overall accuracy of 78% which was significantly higher than the overall accuracy of the Random Forests classification (67%. Most of the error in both classifications was associated with confusion between spectrally similar classes dominated by grasses, such as Hymenachne and Pseudoraphis. In addition, the extent of the sedge Eleocharis was under-estimated in both cases. This suggests the method could be useful for mapping wetlands where statistical-based supervised classifications have achieved less than satisfactory results. Based upon the results, the decision tree method will form part of an ongoing operational monitoring program.

  10. Quantitative FRET Analysis by Fast Acquisition Time Domain FLIM at High Spatial Resolution in Living Cells

    Science.gov (United States)

    Padilla-Parra, Sergi; Audugé, Nicolas; Coppey-Moisan, Maïté; Tramier, Marc

    2008-01-01

    Quantitative analysis in Förster resonance energy transfer (FRET) experiments in live cells for protein interaction studies is still a challenging issue. In a two-component system (FRET and no FRET donor species), fitting of fluorescence lifetime imaging microscopy (FLIM) data gives the fraction of donor molecules involved in FRET (fD) and the intrinsic transfer efficiency. But when fast FLIM acquisitions are used to monitor dynamic changes in protein-protein interactions at high spatial and temporal resolutions in living cells, photon statistics and time resolution are limited. In this case, fitting procedures are not reliable, even for single lifetime donors. We introduce the new concept of a minimal fraction of donor molecules involved in FRET (mfD), coming from the mathematical minimization of fD. We find particular advantage in the use of mfD because it can be obtained without fitting procedures and it is derived directly from FLIM data. mfD constitutes an interesting quantitative parameter for live cell studies because it is related to the minimal relative concentration of interacting proteins. For multi-lifetime donors, the process of fitting complex fluorescence decays to find at least four reliable lifetimes is a near impossible task. Here, mfD extension for multi-lifetime donors is the only quantitative determinant. We applied this methodology for imaging the interaction between the bromodomains of TAFII250 and acetylated histones H4 in living cells at high resolution. We show the existence of discrete acetylated chromatin domains where the minimal fraction of bromodomain interacting with acetylated H4 oscillates from 0.26 to 0.36 and whose size is smaller than half of one micron cube. We demonstrate that mfD by itself is a useful tool to investigate quantitatively protein interactions in live cells, especially when using fast FRET-FLIM acquisition times. PMID:18539634

  11. High spatial resolution mapping of water quality and bathymetry with an autonomous underwater vehicle

    Science.gov (United States)

    Pampalone, Vincenzo; Milici, Barbara

    2015-12-01

    The drone Ecomapper AUV (Autonomous Underwater Vehicle) is a rare example of highly technological instrument in the environmental coastal monitoring field. The YSI EcoMapper is a one-man deployable, Autonomous Underwater Vehicle (AUV) designed to collect bathymetry and water quality data. The submarine-like vehicle follows a programmed course and employs sensors mounted in the nose to record pertinent information. Once the vehicle has started its mission, it operates independently of the user and utilizes GPS waypoints navigation to complete its programmed course. Throughout the course, the vehicle constantly steers toward the line drawn in the mission planning software (VectorMap), essentially following a more accurate road of coordinates instead of transversing waypoint-to-waypoint. It has been equipped with a Doppler Velocity Log (DVL) to increase its underwater navigation accuracy. Potential EcoMapper applications include baseline environmental mapping in freshwater, estuarine or near-coastal environments, bathymetric mapping, dissolved oxygen studies, event monitoring (algal blooms, storm impacts, low dissolved oxygen), non-point source studies, point-source dispersion mapping, security, search & rescue, inspection, shallow water mapping, thermal dissipation mapping of cooling outfalls, trace-dye studies. The AUV is used in the coastal area of the Augusta Bay (Italy), located in the eastern part of Sicily. Due to the heavy contamination generated by the several chemical and petrochemical industries active in the zone, the harbour was declared a Contaminated Site of National Interest. The ecomapper allows for a simultaneous data collection of water quality and bathymetric data providing a complete environmental mapping system of the Harbour.

  12. Operational shoreline mapping with high spatial resolution radar and geographic processing

    Science.gov (United States)

    Rangoonwala, Amina; Jones, Cathleen E; Chi, Zhaohui; Ramsey, Elijah W.

    2017-01-01

    A comprehensive mapping technology was developed utilizing standard image processing and available GIS procedures to automate shoreline identification and mapping from 2 m synthetic aperture radar (SAR) HH amplitude data. The development used four NASA Uninhabited Aerial Vehicle SAR (UAVSAR) data collections between summer 2009 and 2012 and a fall 2012 collection of wetlands dominantly fronted by vegetated shorelines along the Mississippi River Delta that are beset by severe storms, toxic releases, and relative sea-level rise. In comparison to shorelines interpreted from 0.3 m and 1 m orthophotography, the automated GIS 10 m alongshore sampling found SAR shoreline mapping accuracy to be ±2 m, well within the lower range of reported shoreline mapping accuracies. The high comparability was obtained even though water levels differed between the SAR and photography image pairs and included all shorelines regardless of complexity. The SAR mapping technology is highly repeatable and extendable to other SAR instruments with similar operational functionality.

  13. Derivation of high spatial resolution albedo from UAV digital imagery: application over the Greenland Ice Sheet

    Science.gov (United States)

    Ryan, Jonathan C.; Hubbard, Alun; Box, Jason E.; Brough, Stephen; Cameron, Karen; Cook, Joseph M.; Cooper, Matthew; Doyle, Samuel H.; Edwards, Arwyn; Holt, Tom; Irvine-Fynn, Tristram; Jones, Christine; Pitcher, Lincoln H.; Rennermalm, Asa K.; Smith, Laurence C.; Stibal, Marek; Snooke, Neal

    2017-05-01

    Measurements of albedo are a prerequisite for modelling surface melt across the Earth's cryosphere, yet available satellite products are limited in spatial and/or temporal resolution. Here, we present a practical methodology to obtain centimetre resolution albedo products with accuracies of 5% using consumer-grade digital camera and unmanned aerial vehicle (UAV) technologies. Our method comprises a workflow for processing, correcting and calibrating raw digital images using a white reference target, and upward and downward shortwave radiation measurements from broadband silicon pyranometers. We demonstrate the method with a set of UAV sorties over the western, K-sector of the Greenland Ice Sheet. The resulting albedo product, UAV10A1, covers 280 km2, at a resolution of 20 cm per pixel and has a root-mean-square difference of 3.7% compared to MOD10A1 and 4.9% compared to ground-based broadband pyranometer measurements. By continuously measuring downward solar irradiance, the technique overcomes previous limitations due to variable illumination conditions during and between surveys over glaciated terrain. The current miniaturization of multispectral sensors and incorporation of upward facing radiation sensors on UAV packages means that this technique will likely become increasingly attractive in field studies and used in a wide range of applications for high temporal and spatial resolution surface mapping of debris, dust, cryoconite and bioalbedo and for directly constraining surface energy balance models.

  14. High spatial resolution aerosol retrieval with MAIAC: Application to mountain regions

    National Research Council Canada - National Science Library

    Emili, E; Lyapustin, A; Wang, Y; Popp, C; Korkin, S; Zebisch, M; Wunderle, S; Petitta, M

    2011-01-01

    .... Satellites provide an effective tool to map aerosols on an operational basis, but most of the aerosol products intended for continental/global applications have a coarse spatial resolution (10–18 km...

  15. MODIS AOD retrieval at high spatial resolution with MAIAC on the Alpine region

    Science.gov (United States)

    Emili, E.; Lyapustin, A.; Wang, Y.; Korkin, S.; Popp, C. T.; Petitta, M.; Wunderle, S.; Zebisch, M.

    2011-12-01

    Satellite data allow to determine the spatial distribution and variability of aerosols at a large scale. The standard products are developed for global applications and have a coarse resolution, for example 10 km for MODIS standard product (MOD04) Aerosol Optical Depth (AOD). On the other hand, the concentration of aerosols in in mountain regions like the Alps, is very heterogeneous and characterized by scales of variability of several kilometers. Therefore, satellite high resolution products are needed to provide an accurate aerosol mapping in mountain areas. Several approaches to derive aerosol optical depth (AOD) from MODIS at high resolution have been proposed in the recent years. They provide new opportunities for regional scale analysis, but application of these algorithms remains confined to few studies. Recently, the Multi-Angle Implementation of Atmospheric Correction (MAIAC) algorithm was developed for MODIS, which performs a simultaneous retrieval of surface bidirectional reflection and aerosol properties at a resolution of 1km. This algorithm has a global scope and works over both dark and bright surfaces; it has an internal cloud mask and snow detection, and provides an enhanced data coverage with respect to the MODIS standard product, which is very appealing for the Alpine region. In this study we analyze the quality and potential of MAIAC AOD in the European Alpine region using the 1 km resolution AOD maps for the years 2008-2009. Since unresolved clouds and snow pixel contamination increase the noise of the AOD retrieval, we developed a filter that preserves the spatial resolution of the product and enhances the accuracy of MAIAC AOD for air-quality and climatological applications. The filtering approach is divided in three steps: a coarse and fine mode fraction filter, a proximity-cloud filter and an AOD standard deviation filter. The MAIAC AOD was validated with AERONET measurements in the region and compared with MODIS product MOD04. Similar accuracies are found for both products (RMSE=0.05) but with MAIAC providing about 50% more observations in the area, because of its higher spatial resolution and less restrictive filtering. Comparison with ground measurements of aerosol mass (PM10) shows that MAIAC AOD can be used to detect the fine scales of aerosol variability (2-3 km) in the mountains. Evidence of AOD variability in the mountains (up to 0.1-0.2) at scales of several km (width of valleys) is confirmed by the satellite retrieval. Finally, AOD maps for the Alpine region demonstrate that topography is correlated with the average aerosol spatial distribution. We conclude that 1km retrieval gives valuable insights for mapping aerosols in a topographically complex terrain, provided that some care is used with cloud/snow related artifacts. Sampling frequency has been quantified in the region and is everywhere lower than 50%, but the product of AOD accuracy and sampling frequency with MAIAC is higher than the one achievable with other polar orbiting sensors or MODIS global AOD algorithm.

  16. Reconstruction of the Abydos ROSETTA/Philae landing site at very high spatial resolution

    Science.gov (United States)

    Capanna, Claire; Jorda, Laurent; Lamy, Philippe L.; Gaskell, Robert W.; FAURY, Guillaume; DELMAS, Cédric; DURAND, Joelle; GAUDON, Philippe; GARMIER, Romain; JURADO, Eric; OSIRIS Team

    2016-10-01

    The Rosetta/Philae module landed in a very uneven area called Abydos. The landing site has beenidentified on images of this region acquired by the OSIRIS imaging system aboard the orbiterbefore (Oct. 2014) and after (Dec. 2014) the landing (Lamy et al., in prep.).Abydos exhibits a complex topography including numerous cliffs, several overhangs and lots ofboulders (Lucchetti et al. A&A 585, L1, 2016). This makes its reconstruction a challenging taskfor 3D reconstruction techniques.We use a very carefully selected set of high-resolution OSIRIS images acquired betweenMarch 2016 and August 2016 to reconstruct the detailed topography of the Abydos neighborhoodusing a method called ``multiresolution photoclinometry by deformation'' (MPCD, Capanna et al.,The Visual Computer, 29(6-8): 825-835, 2013). We also check the compatibility of the local DTMcomparing the panoramic images obtained by the CIVA-P instrument aboard PHILAE with syntheticimages created with the DTM, and we compute the distances, incidence and emission angles duringthe acquisition of these images.

  17. HIGH SPATIAL RESOLUTION X-RAY SPECTROSCOPY OF THE IC 443 PULSAR WIND NEBULA AND ENVIRONS

    Energy Technology Data Exchange (ETDEWEB)

    Swartz, Douglas A.; Zavlin, Vyacheslav E. [USRA, Astrophysics Office, NASA Marshall Space Flight Center, ZP12, Huntsville, AL 35812 (United States); Pavlov, George G. [Department of Astronomy and Astrophysics, Pennsylvania State University, 525 Davey Lab, University Park, PA 16802 (United States); Clarke, Tracy [Remote Sensing Division, Code 7213, Naval Research Laboratory, 4555 Overlook Avenue, SW, Washington, DC (United States); Castelletti, Gabriela [Instituto de Astronomía y Física del Espacio (IAFE, CONICET-UBA), CC67, Suc. 28, 1428, Buenos Aires (Argentina); Bucciantini, Niccolò [INAF—Osservatorio Astrofisico di Arcetri, L. go E. Fermi 5, I-50125 Firenze (Italy); Karovska, Margarita [Smithsonian Astrophysical Observatory, MS 4, 60 Garden Street, Cambridge, MA 02138 (United States); Horst, Alexander J. van der [Department of Physics, The George Washington University, 725 21 Street NW, Washington, DC 20052 (United States); Yukita, Mihoko [The Johns Hopkins University, Homewood Campus, Baltimore, MD 21218 (United States); Weisskopf, Martin C. [Astrophysics Office, NASA Marshall Space Flight Center, ZP12, Huntsville, AL 35812 (United States)

    2015-07-20

    Deep Chandra ACIS observations of the region around the putative pulsar, CXOU J061705.3+222127, in the supernova remnant (SNR) IC 443 reveal an ∼5″ radius ring-like structure surrounding the pulsar and a jet-like feature oriented roughly north–south across the ring and through the pulsar's location at 06{sup h}17{sup m}5.{sup s}200 + 22°21′27.″52 (J2000.0 coordinates). The observations further confirm that (1) the spectrum and flux of the central object are consistent with a rotation-powered pulsar, (2) the non-thermal spectrum and morphology of the surrounding nebula are consistent with a pulsar wind, and (3) the spectrum at greater distances is consistent with thermal emission from the SNR. The cometary shape of the nebula, suggesting motion toward the southwest, appears to be subsonic: There is no evidence either spectrally or morphologically for a bow shock or contact discontinuity; the nearly circular ring is not distorted by motion through the ambient medium; and the shape near the apex of the nebula is narrow. Comparing this observation with previous observations of the same target, we set a 99% confidence upper limit to the proper motion of CXOU J061705.3+222127 to be less than 44 mas yr{sup −1} (310 km s{sup −1} for a distance of 1.5 kpc), with the best-fit (but not statistically significant) projected direction toward the west.

  18. Helium beam shadowing for high spatial resolution patterning of antibodies on microstructured diagnostic surfaces

    Science.gov (United States)

    Cacao, Eliedonna; Sherlock, Tim; Nasrullah, Azeem; Kemper, Steven; Knoop, Jennifer; Kourentzi, Katerina; Ruchhoeft, Paul; Stein, Gila E; Atmar, Robert L; Willson, Richard C

    2013-01-01

    Abstract We have developed a technique for the high-resolution, self-aligning, and high-throughput patterning of antibody binding functionality on surfaces by selectively changing the reactivity of protein-coated surfaces in specific regions of a workpiece with a beam of energetic helium particles. The exposed areas are passivated with bovine serum albumin (BSA) and no longer bind the antigen. We demonstrate that patterns can be formed (1) by using a stencil mask with etched openings that forms a patterned exposure, or (2) by using angled exposure to cast shadows of existing raised microstructures on the surface to form self-aligned patterns. We demonstrate the efficacy of this process through the patterning of anti-lysozyme, anti-Norwalk virus, and anti-Escherichia coli antibodies and the subsequent detection of each of their targets by the enzyme-mediated formation of colored or silver deposits, and also by binding of gold nanoparticles. The process allows for the patterning of three-dimensional structures by inclining the sample relative to the beam so that the shadowed regions remain unaltered. We demonstrate that the resolution of the patterning process is of the order of hundreds of nanometers, and that the approach is well-suited for high throughput patterning. PMID:24706125

  19. High Spatial Resolution Visible Color Units on Mars from the Mars Odyssey THEMIS/VIS Instrument

    Science.gov (United States)

    Bell, J. F., III; McConnochie, T.; Savransky, D.; Stiglitz, B.; Wolff, M. J.; Christensen, P. R.; Mehall, G.; James, P. B.; Malin, M.; Caplinger, M.; Ravine, M.; Cherednik, L. L.; Bender, K. C.; Murray, K.; Themis Science Team

    2003-07-01

    This presentation describes the calibration and new results from the Mars Odyssey THEMIS/VIS instrument, which is obtaining five-color visible wavelength images from Mars orbit at scales of 18 72 m/pixel.

  20. High spatial resolution radiation detectors based on hydrogenated amorphous silicon and scintillator

    Energy Technology Data Exchange (ETDEWEB)

    Jing, Tao [Univ. of California, Berkeley, CA (United States). Dept. of Engineering-Nuclear Engineering

    1995-05-01

    Hydrogenated amorphous silicon (a-Si:H) as a large-area thin film semiconductor with ease of doping and low-cost fabrication capability has given a new impetus to the field of imaging sensors; its high radiation resistance also makes it a good material for radiation detectors. In addition, large-area microelectronics based on a-Si:H or polysilicon can be made with full integration of peripheral circuits, including readout switches and shift registers on the same substrate. Thin a-Si:H p-i-n photodiodes coupled to suitable scintillators are shown to be suitable for detecting charged particles, electrons, and X-rays. The response speed of CsI/a-Si:H diode combinations to individual particulate radiation is limited by the scintillation light decay since the charge collection time of the diode is very short (< 10ns). The reverse current of the detector is analyzed in term of contact injection, thermal generation, field enhanced emission (Poole-Frenkel effect), and edge leakage. A good collection efficiency for a diode is obtained by optimizing the p layer of the diode thickness and composition. The CsI(Tl) scintillator coupled to an a-Si:H photodiode detector shows a capability for detecting minimum ionizing particles with S/N ~20. In such an arrangement a p-i-n diode is operated in a photovoltaic mode (reverse bias). In addition, a p-i-n diode can also work as a photoconductor under forward bias and produces a gain yield of 3--8 for shaping times of 1 {micro}s. The mechanism of the formation of structured CsI scintillator layers is analyzed. Initial nucleation in the deposited layer is sensitive to the type of substrate medium, with imperfections generally catalyzing nucleation. Therefore, the microgeometry of a patterned substrate has a significant effect on the structure of the CsI growth.

  1. Unexpected materials in a Rembrandt painting characterized by high spatial resolution cluster-TOF-SIMS imaging.

    Science.gov (United States)

    Sanyova, Jana; Cersoy, Sophie; Richardin, Pascale; Laprévote, Olivier; Walter, Philippe; Brunelle, Alain

    2011-02-01

    The painting materials of the Portrait of Nicolaes van Bambeeck (Royal Museums of Fine Arts of Belgium, Brussels, inv. 155) painted by Rembrandt van Rijn in 1641 has been studied using high resolution cluster-TOF-SIMS imaging. In the first step, a moderate spatial resolution (2 μm) was used to characterize the layer structure and the chemical composition of each layer on account of a high mass resolution. Then, in the second step, and despite a low mass resolution, the cluster primary ion beam was focused well below 1 μm in order to reveal smaller structures in the painting sample. The study confirmed the presence of starch in the second ground layer, which is quite surprising and, at least for Rembrandt paintings, has never been reported before. TOF-SIMS also indicated the presence of proteins, which, added to the size and shape of lake particles, suggests that it was manufactured from shearings (waste of textile manufacturing) of dyed wool, used as the source of the dyestuff. The analyses have also shown various lead carboxylates, being the products of the interaction between lead white and the oil of the binding medium. These findings considerably contribute to the understanding of Rembrandt's studio practice and thus demonstrate the importance and potential of cluster-TOF-SIMS imaging in the characterization on a submicrometer scale of artist painting materials.

  2. Numerical modeling of permafrost dynamics in Alaska using a high spatial resolution dataset

    OpenAIRE

    Jafarov, E.E.; S. S. Marchenko; Romanovsky, V. E.

    2012-01-01

    Climate projections for the 21st century indicate that there could be a pronounced warming and permafrost degradation in the Arctic and sub-Arctic regions. Climate warming is likely to cause permafrost thawing with subsequent effects on surface albedo, hydrology, soil organic matter storage and greenhouse gas emissions. To assess possible changes in the permafrost thermal state and active layer thickness, we implemented the GIPL2-MPI transient numerical model for the entire Alaska permafrost ...

  3. Numerical modeling of permafrost dynamics in Alaska using a high spatial resolution dataset

    OpenAIRE

    Jafarov, E.E.; S. S. Marchenko; Romanovsky, V. E.

    2012-01-01

    Climate projections for the 21st century indicate that there could be a pronounced warming and permafrost degradation in the Arctic and sub-Arctic regions. Climate warming is likely to cause permafrost thawing with subsequent effects on surface albedo, hydrology, soil organic matter storage and greenhouse gas emissions.

    To assess possible changes in the permafrost thermal state and active layer thickness, we implemented the GIPL2-MPI transient numerical model for the enti...

  4. Measuring the hydrogen/deuterium exchange of proteins at high spatial resolution by mass spectrometry

    DEFF Research Database (Denmark)

    Rand, Kasper Dyrberg; Zehl, Martin; Jørgensen, Thomas J D

    2014-01-01

    the sum of the exchange kinetics for the individual backbone amides. Local exchange kinetics is typically achieved by using pepsin digestion under quench conditions (i.e., under cold acidic conditions where the amide hydrogen exchange rate is slowed by many orders of magnitude). The ability to localize...... resolution of the lowest-energy structure of the native ensemble. There is a growing need for sensitive analytical tools to explore all of the significant molecular structures in the conformational landscape of proteins. Hydrogen/deuterium exchange monitored by mass spectrometry (HDX-MS) has recently emerged...... as a powerful method for characterizing protein conformational dynamics. The basis of this method is the fact that backbone amides in stable hydrogen-bonded structures (e.g., α-helices and β-sheets) are protected against exchange with the aqueous solvent. All protein structures are dynamic, however...

  5. High spatial resolution fast-neutron imaging detectors for Pulsed Fast-Neutron Transmission Spectroscopy

    Science.gov (United States)

    Mor, I.; Vartsky, D.; Bar, D.; Feldman, G.; Goldberg, M. B.; Katz, D.; Sayag, E.; Shmueli, I.; Cohen, Y.; Tal, A.; Vagish, Z.; Bromberger, B.; Dangendorf, V.; Mugai, D.; Tittelmeier, K.; Weierganz, M.

    2009-05-01

    Two generations of a novel detector for high-resolution transmission imaging and spectrometry of fast-neutrons are presented. These devices are based on a hydrogenous fiber scintillator screen and single- or multiple-gated intensified camera systems (ICCD). This detector is designed for energy-selective neutron radiography with nanosecond-pulsed broad-energy (1-10 MeV) neutron beams. Utilizing the Time-of-Flight (TOF) method, such a detector is capable of simultaneously capturing several images, each at a different neutron energy (TOF). In addition, a gamma-ray image can also be simultaneously registered, allowing combined neutron/gamma inspection of objects. This permits combining the sensitivity of the fast-neutron resonance method to low-Z elements with that of gamma radiography to high-Z materials.

  6. High spatial resolution observations of NGC 7027 with a 10 micron array camera

    Science.gov (United States)

    Arens, J. F.; Lamb, G. M.; Peck, M. C.; Moseley, H.; Hoffmann, W. F.; Tresch-Fienberg, R.; Fazio, G. G.

    1984-01-01

    First observations of a planetary nebula with an infrared charge injection device (CID) array camera are reported. The 10 micron images of NGC 7027 have spatial resolution comparable to that of the highest resolution (less than 2 arcsec) radio aperture-synthesis maps of this source. A much closer correspondence between the mid-infrared and radio appearance of NGC 7027 was found than was known previously, confirming that warm dust is coextensive and well mixed with the gas in the ionized zone. Using maps at three wavelengths, the spatial dependence of the shape of the 8-13 micron spectrum within the nebula is examined. The dip at 9.60 microns is shallowest in regions of enhanced optical extinction (as determined from new images near 4000 and 9000 A obtained with an optical charge coupled device). The 9.60 micron emission is strongest in these same positions. It is shown that the results may be explained not by silicate absorption, but by a combination of emission from two distinct grain populations, one of which is also partly responsible for the variation in extinction across the nebula.

  7. Two-dimensional high spatial-resolution dosimeter using europium doped potassium chloride: a feasibility study

    Science.gov (United States)

    Li, H. Harold; Driewer, Joseph P.; Han, Zhaohui; Low, Daniel A.; Yang, Deshan; Xiao, Zhiyan

    2014-01-01

    Recent research has shown that KCl:Eu2+ has great potential for use in megavoltage radiation therapy dosimetry because this material exhibits excellent storage performance and is reusable due to strong radiation hardness. This work reports the authors’ attempts to fabricate 2D KCl:Eu2+ storage phosphor films (SPFs) using both a physical vapor deposition (PVD) method and a tape casting method. X ray diffraction analysis showed that a 10 µm thick PVD sample was composed of highly crystalline KCl. No additional phases were observed, suggesting that the europium activator had completed been incorporated into the KCl matrix. Photostimulated luminescence and photoluminescence spectra suggested that F (Cl-) centers were the electron storage centers post×ray irradiation and that Eu2+ cations acted as luminescence centers in the photostimulation process. The 150-µm thick casted KCl:Eu2+ SPF showed sub-millimeter spatial resolution. Monte Carlo simulations further demonstrated that the admixture of 20% KCl:Eu2+ and 80% low Z polymer binder exhibited almost no energy dependence in a 6 MV beam. KCl:Eu2+ pellet samples showed a large dynamic range from 0.01 cGy to 60 Gy dose-to-water, and saturated at approximately 500 Gy as a result of KCl’s intrinsic high radiation hardness. Taken together, this work provides strong evidence that KCl:Eu2+ based SPF with associated readout apparatus could result in a novel electronic film system that has all the desirable features associated with classic radiographic film and, importantly, water equivalence and the capability of permanent identification of each detector. PMID:24651448

  8. A high spatial resolution retrieval of NO 2 column densities from OMI: method and evaluation

    Directory of Open Access Journals (Sweden)

    R. C. Cohen

    2011-08-01

    Full Text Available We present a new retrieval of tropospheric NO2 vertical column density from the Ozone Monitoring Instrument (OMI based on high spatial and temporal resolution terrain and profile inputs. We compare our NO2 product, the Berkeley High-Resolution (BEHR product, with operational retrievals and find that the operational retrievals are biased high (30 % over remote areas and biased low (8 % over urban regions. Additionally, we find non-negligible impacts on the retrieved NO2 column for terrain pressure (±20 %, albedo (±40 %, and NO2 vertical profile (−75 %–+10 %. We validate the operational and BEHR products using boundary layer aircraft observations from the Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS-CA field campaign which occurred in June 2008 in California. Results indicate that columns derived using our boundary layer extrapolation method show good agreement with satellite observations (R2 = 0.65–0.83; N = 68 and provide a more robust validation of satellite-observed NO2 column than those determined using full vertical spirals (R2 = 0.26; N = 5 as in previous work. Agreement between aircraft observations and the BEHR product (R2 = 0.83 is better than agreement with the operational products (R2 = 0.65–0.72. We also show that agreement between satellite and aircraft observations can be further improved (e.g. BEHR: R2 = 0.91 using cloud information from the Moderate Resolution Imaging Spectroradiometer (MODIS instrument instead of the OMI cloud product. These results indicate that much of the variance in the operational products can be attributed to coarse resolution terrain pressure, albedo, and profile parameters implemented in the retrievals.

  9. High spatial resolution mapping of folds and fractures using Unmanned Aerial Vehicle (UAV) photogrammetry

    Science.gov (United States)

    Cruden, A. R.; Vollgger, S.

    2016-12-01

    The emerging capability of UAV photogrammetry combines a simple and cost-effective method to acquire digital aerial images with advanced computer vision algorithms that compute spatial datasets from a sequence of overlapping digital photographs from various viewpoints. Depending on flight altitude and camera setup, sub-centimeter spatial resolution orthophotographs and textured dense point clouds can be achieved. Orientation data can be collected for detailed structural analysis by digitally mapping such high-resolution spatial datasets in a fraction of time and with higher fidelity compared to traditional mapping techniques. Here we describe a photogrammetric workflow applied to a structural study of folds and fractures within alternating layers of sandstone and mudstone at a coastal outcrop in SE Australia. We surveyed this location using a downward looking digital camera mounted on commercially available multi-rotor UAV that autonomously followed waypoints at a set altitude and speed to ensure sufficient image overlap, minimum motion blur and an appropriate resolution. The use of surveyed ground control points allowed us to produce a geo-referenced 3D point cloud and an orthophotograph from hundreds of digital images at a spatial resolution < 10 mm per pixel, and cm-scale location accuracy. Orientation data of brittle and ductile structures were semi-automatically extracted from these high-resolution datasets using open-source software. This resulted in an extensive and statistically relevant orientation dataset that was used to 1) interpret the progressive development of folds and faults in the region, and 2) to generate a 3D structural model that underlines the complex internal structure of the outcrop and quantifies spatial variations in fold geometries. Overall, our work highlights how UAV photogrammetry can contribute to new insights in structural analysis.

  10. Enhanced Sensitivity for High Spatial Resolution Lipid Analysis by Negative Ion Mode MALDI Imaging Mass Spectrometry

    OpenAIRE

    Angel, Peggi M.; Spraggins, Jeffrey M.; Baldwin, H. Scott; Caprioli, Richard

    2012-01-01

    We have achieved enhanced lipid imaging to a ~10 μm spatial resolution using negative ion mode matrix assisted laser desorption ionization (MALDI) imaging mass spectrometry, sublimation of 2,5-dihydroxybenzoic acid as the MALDI matrix and a sample preparation protocol that uses aqueous washes. We report on the effect of treating tissue sections by washing with volatile buffers at different pHs prior to negative ion mode lipid imaging. The results show that washing with ammonium formate, pH 6....

  11. High spatial resolution distributed optical fiber dynamic strain sensor with enhanced frequency and strain resolution.

    Science.gov (United States)

    Masoudi, Ali; Newson, Trevor P

    2017-01-15

    A distributed optical fiber dynamic strain sensor with high spatial and frequency resolution is demonstrated. The sensor, which uses the ϕ-OTDR interrogation technique, exhibited a higher sensitivity thanks to an improved optical arrangement and a new signal processing procedure. The proposed sensing system is capable of fully quantifying multiple dynamic perturbations along a 5 km long sensing fiber with a frequency and spatial resolution of 5 Hz and 50 cm, respectively. The strain resolution of the sensor was measured to be 40 nε.

  12. Predicting vehicular emissions in high spatial resolution using pervasively measured transportation data and microscopic emissions model

    Energy Technology Data Exchange (ETDEWEB)

    Nyhan, Marguerite; Sobolevsky, Stanislav; Kang, Chaogui; Robinson, Prudence; Corti, Andrea; Szell, Michael; Streets, David; Lu, Zifeng; Britter, Rex; Barrett, Steven R. H.; Ratti, Carlo

    2016-06-07

    Air pollution related to traffic emissions pose an especially significant problem in cities; this is due to its adverse impact on human health and well-being. Previous studies which have aimed to quantify emissions from the transportation sector have been limited by either simulated or coarsely resolved traffic volume data. Emissions inventories form the basis of urban pollution models, therefore in this study, Global Positioning System (GPS) trajectory data from a taxi fleet of over 15,000 vehicles were analyzed with the aim of predicting air pollution emissions for Singapore. This novel approach enabled the quantification of instantaneous drive cycle parameters in high spatio-temporal resolution, which provided the basis for a microscopic emissions model. Carbon dioxide (CO2), nitrogen oxides (NOx), volatile organic compounds (VOCs) and particulate matter (PM) emissions were thus estimated. Highly localized areas of elevated emissions levels were identified, with a spatio-temporal precision not possible with previously used methods for estimating emissions. Relatively higher emissions areas were mainly concentrated in a few districts that were the Singapore Downtown Core area, to the north of the central urban region and to the east of it. Daily emissions quantified for the total motor vehicle population of Singapore were found to be comparable to another emissions dataset Results demonstrated that high resolution spatio-temporal vehicle traces detected using GPS in large taxi fleets could be used to infer highly localized areas of elevated acceleration and air pollution emissions in cities, and may become a complement to traditional emission estimates, especially in emerging cities and countries where reliable fine-grained urban air quality data is not easily available. This is the first study of its kind to investigate measured microscopic vehicle movement in tandem with microscopic emissions modeling for a substantial study domain.

  13. Coeval Formation of Zircon Megacrysts and Host Magmas in the Eifel Volcanic Field (Germany) Based on High Spatial Resolution Petrochronology

    Science.gov (United States)

    Schmitt, Axel; Klitzke, Malte; Gerdes, Axel; Ludwig, Thomas; Schäfer, Christof

    2017-04-01

    Zircon megacrysts (approx. 0.5-6 mm in diameter) from the Quaternary West and East Eifel volcanic fields, Germany, occur as euhedral crystals in porous K-spar rich plutonic ejecta clasts, and as partially resorbed xenocrysts in tephrite lava. Their relation to the host volcanic rocks has remained contentious because the dominantly basanitic to phonolitic magma compositions in the Eifel are typically zircon undersaturated. We carried out a detailed microanalytical study of zircon megacrysts from seven locations (Emmelberg and Rockeskyll in the West Eifel; Bellerberg, Laacher See, Mendig, Rieden, and Wehr in the East Eifel). Crystals were embedded in epoxy, sectioned to expose interiors through grinding with abrasives, diamond-polished, and mapped by optical microscopy, backscattered electron, and cathodoluminescence imaging. Subsequently, isotope-specific analysis using secondary ionization mass spectrometry (SIMS) and laser ablation inductively coupled mass spectrometry (LA-ICP-MS) was carried out placing 100 correlated spots on 20 selected crystals. Concordant U-Th disequilibrium and U-Pb ages determined by SIMS are between ca. 430 ka (Rieden) and 170 ka (Mendig) and indicate that the megacryst zircons crystallized almost always briefly before eruption. A significant gap between zircon megacryst crystallization (ca. 230 ka) and eruption (ca. 45 ka) ages was only detected for the Emmelberg location. SIMS trace element abundances (e.g., rare earth elements) vary by orders-of-magnitude and correlate with domain boundaries visible in cathodoluminescence; trace element patterns match those reported for zircon from syenitic origins. Isotopic compositions are homogeneous within individual crystals, but show some heterogeneity between different crystals from the same locality. Average isotopic values (δ18O SMOW = +5.3±0.6 ‰ by SIMS; present-day ɛHf = +1.7±2.5 ‰ by LA-ICP-MS; 1 standard deviation), however, are consistent with source magmas being dominantly mantle-derived. The porous structure and relatively small grain size of the host enclaves suggests that they originated from subvolcanic intrusions. Moreover, the preservation of zircon in hot, zircon undersaturated magmas requires brief residence times. Zircon megacrysts thus appear to have crystallized in highly differentiated magmas or nearly solidified intrusions from which crystals or rock aggregates were incorporated into more primitive magmas en route to surface. This implies that chemical signatures of apparently primitive magmas in basaltic volcanic fields can be modified by interaction with evolved melts that differentiated prior to eruption, mostly within an interval less than the ca. 10-25 ka uncertainty range of the radiometric ages.

  14. Methods for automatic identification and extraction of terraces from high spatial resolution satellite data (China-GF-1

    Directory of Open Access Journals (Sweden)

    Yi Zhang

    2017-03-01

    Full Text Available Terraces are effective measures to control soil and water loss on hillslopes and play significant roles in water storage, soil conservation and increasing of crop yield. With the launch of comprehensive management engineering of transforming slopes into terraces in China, the area of terraces is continuously expanding. To plan for soil and water conservation in a scientific way and ensure rational soil and water conservation measures, it is important to determine a timely and accurate inventory of the spatial distribution of the existing terraces. High-resolution satellite data (China GF-1 was used in this study to automatically identify and extract terraces. The edge characteristics statistics algorithm, template-matching algorithm and the Fourier transformation algorithm were used. The results suggest that the template-matching algorithm, based on high gray features of terraces, has higher identification accuracy and lower extraction miss rate, and is able to determines the complete map spots, which works well for identification and extraction of typical terraces. The Fourier transformation algorithm, based on the texture of the terraces, is easily affected by gray changes on the terrace field surfaces and field ridges and is hardly reliable as a stand-alone technique for terrace identification. In this study, we focused on an area near Hengshan County, Yulin of Shanxi Province, and performed field validation of the terrace automatic identification and extraction algorithms. The results suggest that the accuracy of automatic identification and extraction of the terraces is greater than 80%. The method proposed is helpful to meet the requirements for planning and monitoring soil and water conservation projects.

  15. Energy-selective neutron imaging with high spatial resolution and its impact on the study of crystalline-structured materials

    Energy Technology Data Exchange (ETDEWEB)

    Lehmann, E.H., E-mail: eberhard.lehmann@psi.ch [Neutron Imaging and Activation Group, Spallation Neutron Source Division, Paul Scherrer Institut, CH-5232 Villigen, PSI (Switzerland); Peetermans, S.; Josic, L. [Neutron Imaging and Activation Group, Spallation Neutron Source Division, Paul Scherrer Institut, CH-5232 Villigen, PSI (Switzerland); Leber, H. [W. Blösch AG, CH-2540 Grenchen, P.O. Box 244 (Switzerland); Swygenhoven, H. van [Material Science and Simulation Group, Spallation Neutron Source Division, Paul Scherrer Institut, CH-5232 Villigen, PSI (Switzerland)

    2014-01-21

    Crystalline-structured materials with preferentially large grains were investigated by means of energy-selective neutron imaging methods (transmission radiography and tomography) under the conditions of the best possible spatial resolution at the ICON facility, SINQ, and PSI. Because of the cold spectrum at that beam line, access to the Bragg diffraction features was possible even when the energy resolution of the used selector device was only 15%. Grains with a size below the detector resolution (approximately 25 μm) are not visible, and a quasi-homogeneous contrast variation is found when the neutron energy is varied.In the cases of welded stainless steel samples and rolled Al plates, we obtained structural information from a very short exposure of approximately 60 s. Tomographic examinations of these samples at suitable neutron energies qualitatively verified the radiographic findings by showing the same features in the bulk. Comparison to common electron backscatter diffraction (EBSD) investigations in selected regions of the samples provided a complete verification of the neutron-image data with respect to the grain size and the different grain orientations. The method of energy-selective neutron imaging provides an easy and straightforward approach for non-invasive material research that can be performed without any sample preparation if the most suitable neutron energy is chosen. Further studies will be necessary to extend the experimental data base to other materials with different crystal structures and grain sizes. A comparison to diffraction data will enhance the quantitative value of the investigations.

  16. Normal anal sphincter anatomy and age- and sex-related variations at high-spatial-resolution endoanal MR imaging

    NARCIS (Netherlands)

    Rociu, E.; Stoker, J.; Eijkemans, M. J.; Laméris, J. S.

    2000-01-01

    To describe the various patterns of normal sphincter anatomy as seen at endoanal magnetic resonance (MR) imaging and to assess sex- and age-related variations in the dimensions of the anal sphincter to refine the diagnosis of sphincter disorders. Endoanal MR imaging (1.5 T) was performed in 100

  17. Detection of Sinkhole Activity in Central Florida with High Spatial-Resolution InSAR Time Series Observations

    Science.gov (United States)

    Oliver-Cabrera, T.; Wdowinski, S.; Kruse, S.

    2016-12-01

    Central Florida's thick carbonate deposits and hydrological conditions make the area prone to sinkhole development. Sinkhole collapse is a major geologic hazard, threatening human life and causing substantial damage to property. Detecting sinkhole deformation before a collapse is a difficult task, due to small and typically unnoticeable surface changes. Most techniques used to map sinkholes, such as ground penetrating radar, require ground contact and are practical for localized (typically 2D, tens to hundreds of meters) surveys but not for broad study areas. In this study we use Persistent Scatterer (PS) time series analysis of Interferometric Synthetic Aperture Radar (InSAR), which is a very useful technique for detecting localized deformation while covering vast areas. We acquired SAR images over four locations in central Florida in order to detect possible pre-collapse or slow subsidence surface movements. The data used in this study were acquired by TerraSAR-X and COSMO-SkyMed satellites with pixel resolutions ranging between 25cm and 2m. To date, we have obtained four datasets, each of 25-30 acquisitions, covering a period of roughly one year over a total of roughly 2200 km2. We also installed two corner reflectors over a subsiding sinkhole located in an open vegetated area, to provide strong scattering and improve coherence over that particular location. We generate PS time series for each of the four datasets. Preliminary results show localized deformation at several houses and commercial buildings in several locations. Deforming areas vary in size from approximately 10mx20m of a single house to 60mx60m for a commercial building. On site ground penetrating radar surveys will be performed in these areas to verify their relationship to possible sinkhole activities. Our results also confirm that the corner reflectors improved PS detection over low coherence areas.

  18. Preparing a landslide and shadow inventory map from high-spatial-resolution imagery facilitated by an expert system

    Science.gov (United States)

    Liu, Cheng-Chien

    2015-01-01

    An expert system was developed to integrate all useful spatial information and help the interpreters determine the landslide and shaded areas quickly and accurately. The intersection of two spectral indices, namely the normalized difference vegetation index and the normalized green red difference index, as well as the first principle component of the panchromatic band, is employed to automatically determine the regional thresholds of nonvegetation and dark areas. These boundaries are overlaid on the locally enhanced image and the digital topography model to closely inspect each area with a preferred viewing direction. The other geospatial information can be switched on and off to facilitate interpretation. This new approach is tested with 2 m pan-sharpened multispectral imagery from Formosat-2 taken on August 24, 2009, for several disaster areas of Typhoon Morakot. The generated inventory of landslide and shadow areas is validated with the one manually delineated from the 25 cm aerial photos taken on the same day. The production, user, and overall accuracies are higher than 82%, 85%, and 98%, respectively. The fall in production and user accuracies mainly comes from the differences in resolution. This new approach is as accurate as the general approach of manual delineation and visual interpretation, yet significantly reduces the required time.

  19. Evaluation of Landsat-Based METRIC Modeling to Provide High-Spatial Resolution Evapotranspiration Estimates for Amazonian Forests

    Directory of Open Access Journals (Sweden)

    Izaya Numata

    2017-01-01

    Full Text Available While forest evapotranspiration (ET dynamics in the Amazon have been studied both as point estimates using flux towers, as well as spatially coarse surfaces using satellite data, higher resolution (e.g., 30 m resolution ET estimates are necessary to address finer spatial variability associated with forest biophysical characteristics and their changes by natural and human impacts. The objective of this study is to evaluate the potential of the Landsat-based METRIC (Mapping Evapotranspiration at high Resolution with Internalized Calibration model to estimate high-resolution (30 m forest ET by comparing to flux tower ET (FT ET data collected over seasonally dry tropical forests in Rondônia, the southwestern region of the Amazon. Analyses were conducted at daily, monthly and seasonal scales for the dry seasons (June–September for Rondônia of 2000–2002. Overall daily ET comparison between FT ET and METRIC ET across the study site showed r2 = 0.67 with RMSE = 0.81 mm. For seasonal ET comparison, METRIC-derived ET estimates showed an agreement with FT ET measurements during the dry season of r2 >0.70 and %MAE <15%. We also discuss some challenges and potential applications of METRIC for Amazonian forests.

  20. Integrating High Spatial Resolution Weather Radar Data and Urban Imagery for Modeling Micro-scale Dengue Risk

    DEFF Research Database (Denmark)

    Wen, Tzai-Hung; Chen, Tzu-Hsin Karen

    rainwater harvesting and larval habitats. The effects are not measurable and verified unless they are based on suitable data sets and empirical evidence. Numerous attempts in dengue risk assessment by previous works used remote sensed images and classification algorithms to measure land cover and land use...... factors. These studies have confirmed the positive correlation between dengue risk and urbanization. However, precipitation patterns are relate to micro-scale urban environmental features, which may also influence spatial distribution of dengue vector breeding sites. Few studies deal with the interactions...... among precipitation patterns, urban environmental features and mosquito breeding sites. The aims of this study, therefore, focus on two topics. The first is to use spatial-temporal analysis to identify different precipitation patterns with weather radar data. The other is to develop a micro...

  1. Developing a CCD camera with high spatial resolution for RIXS in the soft X-ray range

    Energy Technology Data Exchange (ETDEWEB)

    Soman, M.R., E-mail: m.r.soman@open.ac.uk [e2v centre for electronic imaging, The Open University, Walton Hall, Milton Keynes MK7 6AA (United Kingdom); Hall, D.J.; Tutt, J.H.; Murray, N.J.; Holland, A.D. [e2v centre for electronic imaging, The Open University, Walton Hall, Milton Keynes MK7 6AA (United Kingdom); Schmitt, T.; Raabe, J.; Schmitt, B. [Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland)

    2013-12-11

    The Super Advanced X-ray Emission Spectrometer (SAXES) at the Swiss Light Source contains a high resolution Charge-Coupled Device (CCD) camera used for Resonant Inelastic X-ray Scattering (RIXS). Using the current CCD-based camera system, the energy-dispersive spectrometer has an energy resolution (E/ΔE) of approximately 12,000 at 930 eV. A recent study predicted that through an upgrade to the grating and camera system, the energy resolution could be improved by a factor of 2. In order to achieve this goal in the spectral domain, the spatial resolution of the CCD must be improved to better than 5 µm from the current 24 µm spatial resolution (FWHM). The 400 eV–1600 eV energy X-rays detected by this spectrometer primarily interact within the field free region of the CCD, producing electron clouds which will diffuse isotropically until they reach the depleted region and buried channel. This diffusion of the charge leads to events which are split across several pixels. Through the analysis of the charge distribution across the pixels, various centroiding techniques can be used to pinpoint the spatial location of the X-ray interaction to the sub-pixel level, greatly improving the spatial resolution achieved. Using the PolLux soft X-ray microspectroscopy endstation at the Swiss Light Source, a beam of X-rays of energies from 200 eV to 1400 eV can be focused down to a spot size of approximately 20 nm. Scanning this spot across the 16 µm square pixels allows the sub-pixel response to be investigated. Previous work has demonstrated the potential improvement in spatial resolution achievable by centroiding events in a standard CCD. An Electron-Multiplying CCD (EM-CCD) has been used to improve the signal to effective readout noise ratio achieved resulting in a worst-case spatial resolution measurement of 4.5±0.2 μm and 3.9±0.1 μm at 530 eV and 680 eV respectively. A method is described that allows the contribution of the X-ray spot size to be deconvolved from these worst-case resolution measurements, estimating the spatial resolution to be approximately 3.5 µm and 3.0 µm at 530 eV and 680 eV, well below the resolution limit of 5 µm required to improve the spectral resolution by a factor of 2.

  2. A New Sparse Representation Framework for Reconstruction of an Isotropic High Spatial Resolution MR Volume From Orthogonal Anisotropic Resolution Scans.

    Science.gov (United States)

    Jia, Yuanyuan; Gholipour, Ali; He, Zhongshi; Warfield, Simon K

    2017-05-01

    In magnetic resonance (MR), hardware limitations, scan time constraints, and patient movement often result in the acquisition of anisotropic 3-D MR images with limited spatial resolution in the out-of-plane views. Our goal is to construct an isotropic high-resolution (HR) 3-D MR image through upsampling and fusion of orthogonal anisotropic input scans. We propose a multiframe super-resolution (SR) reconstruction technique based on sparse representation of MR images. Our proposed algorithm exploits the correspondence between the HR slices and the low-resolution (LR) sections of the orthogonal input scans as well as the self-similarity of each input scan to train pairs of overcomplete dictionaries that are used in a sparse-land local model to upsample the input scans. The upsampled images are then combined using wavelet fusion and error backprojection to reconstruct an image. Features are learned from the data and no extra training set is needed. Qualitative and quantitative analyses were conducted to evaluate the proposed algorithm using simulated and clinical MR scans. Experimental results show that the proposed algorithm achieves promising results in terms of peak signal-to-noise ratio, structural similarity image index, intensity profiles, and visualization of small structures obscured in the LR imaging process due to partial volume effects. Our novel SR algorithm outperforms the nonlocal means (NLM) method using self-similarity, NLM method using self-similarity and image prior, self-training dictionary learning-based SR method, averaging of upsampled scans, and the wavelet fusion method. Our SR algorithm can reduce through-plane partial volume artifact by combining multiple orthogonal MR scans, and thus can potentially improve medical image analysis, research, and clinical diagnosis.

  3. Kite Aerial Photography for Low-Cost, Ultra-high Spatial Resolution Multi-Spectral Mapping of Intertidal Landscapes

    Science.gov (United States)

    Bryson, Mitch; Johnson-Roberson, Matthew; Murphy, Richard J.; Bongiorno, Daniel

    2013-01-01

    Intertidal ecosystems have primarily been studied using field-based sampling; remote sensing offers the ability to collect data over large areas in a snapshot of time that could complement field-based sampling methods by extrapolating them into the wider spatial and temporal context. Conventional remote sensing tools (such as satellite and aircraft imaging) provide data at limited spatial and temporal resolutions and relatively high costs for small-scale environmental science and ecologically-focussed studies. In this paper, we describe a low-cost, kite-based imaging system and photogrammetric/mapping procedure that was developed for constructing high-resolution, three-dimensional, multi-spectral terrain models of intertidal rocky shores. The processing procedure uses automatic image feature detection and matching, structure-from-motion and photo-textured terrain surface reconstruction algorithms that require minimal human input and only a small number of ground control points and allow the use of cheap, consumer-grade digital cameras. The resulting maps combine imagery at visible and near-infrared wavelengths and topographic information at sub-centimeter resolutions over an intertidal shoreline 200 m long, thus enabling spatial properties of the intertidal environment to be determined across a hierarchy of spatial scales. Results of the system are presented for an intertidal rocky shore at Jervis Bay, New South Wales, Australia. Potential uses of this technique include mapping of plant (micro- and macro-algae) and animal (e.g. gastropods) assemblages at multiple spatial and temporal scales. PMID:24069206

  4. Assessing Water Stress of Desert Tamarugo Trees Using in situ Data and Very High Spatial Resolution Remote Sensing

    Directory of Open Access Journals (Sweden)

    Edmundo Acevedo

    2013-10-01

    Full Text Available The hyper-arid Atacama Desert is one of the most extreme environments for life and only few species have evolved to survive its aridness. One such species is the tree Prosopis tamarugo Phil. Because Tamarugo completely depends on groundwater, it is being threatened by the high water demand from the Chilean mining industry and the human consumption. In this paper, we identified the most important biophysical variables to assess the water status of Tamarugo trees and tested the potential of WorldView2 satellite images to retrieve these variables. We propose green canopy fraction (GCF and green drip line leaf area index (DLLAIgreen as best variables and a value of 0.25 GCF as a critical threshold for Tamarugo survival. Using the WorldView2 spectral bands and an object-based image analysis, we showed that the NDVI and the Red-edge Chlorophyll Index (CIRed-edge have good potential to retrieve GCF and DLLAIgreen. The NDVI performed best for DLLAIgreen (RMSE = 0.4 while the CIRed-edge was best for GCF (RMSE = 0.1. However, both indices were affected by Tamarugo leaf movements (leaves avoid facing direct solar radiation at the hottest time of the day. Thus, monitoring systems based on these indices should consider the time of the day and the season of the year at which the satellite images are acquired.

  5. High spatial resolution NO2 tropospheric slant columns retrieved from OMI spatial-zoom spectra using an earthshine reference

    Science.gov (United States)

    Anand, Jasdeep S.; Leigh, Roland J.; Monks, Paul S.

    2014-08-01

    Future satellite instruments measuring urban NO2 will need to have high spatio-temporal resolution in order to improve air quality model forecasts. However, the likely cost and data telemetry requirements for such instruments will be high with current techniques. In this work we propose a new retrieval algorithm for deriving tropospheric NO2 slant column densities (SCDs) by DOAS fitting an earthshine reference spectrum measured over the Pacific to account for stratospheric NO2, which would eliminate the need for a solar reference and simplify instrument and retrieval design. The retrieval is tested by fitting earthshine radiance spectra measured by the Ozone Measuring Instrument (OMI) during its spatial-zoom mode (nadir pixel size: 13 x 12 km2) and super-zoom mode (nadir pixel size: 13 x 3 km2) using a Pacific reference spectrum. Transects taken over urban areas showed that the retrieval appears to retrieve tropospheric NO2 SCDs with good agreement with the operational L2 DOMINO product over regions with high NOx emissions. The retrieval also appeared to supress across-track striping without the need for a posteriori correction and showed sensitivity to absorption due to sand and liquid water over deserts and oceans. Comparisons with operational-scale retrievals also showed improved SCD precision, if random noise is expected to be the cause of retrieval uncertainty.

  6. Methodological approaches to planar and volumetric scintigraphic imaging of small volume targets with high spatial resolution and sensitivity

    Energy Technology Data Exchange (ETDEWEB)

    Mejia, J.; Galvis-Alonso, O.Y. [Faculdade de Medicina de Sao Jose do Rio Preto (FAMERP), SP (Brazil). Faculdade de Medicina. Dept. de Biologia Molecular], e-mail: mejia_famerp@yahoo.com.br; Braga, J. [Faculdade de Medicina de Sao Jose do Rio Preto (FAMERP), SP (Brazil). Div. de Astrofisica; Correa, R. [Instituto Nacional de Pesquisas Espaciais (INPE), Sao Jose dos Campos, SP (Brazil). Div. de Ciencia Espacial e Atmosferica; Leite, J.P. [Faculdade de Medicina de Sao Jose do Rio Preto (FAMERP), SP (Brazil). Dept. de Neurologia, Psiquiatria e Psicologia Medica; Simoes, M.V. [Faculdade de Medicina de Sao Jose do Rio Preto (FAMERP), SP (Brazil). Dept. de Clinica Medica

    2009-08-15

    Single-photon emission computed tomography (SPECT) is a non-invasive imaging technique, which provides information reporting the functional states of tissues. SPECT imaging has been used as a diagnostic tool in several human disorders and can be used in animal models of diseases for physiopathological, genomic and drug discovery studies. However, most of the experimental models used in research involve rodents, which are at least one order of magnitude smaller in linear dimensions than man. Consequently, images of targets obtained with conventional gamma-cameras and collimators have poor spatial resolution and statistical quality. We review the methodological approaches developed in recent years in order to obtain images of small targets with good spatial resolution and sensitivity. Multi pinhole, coded mask- and slit-based collimators are presented as alternative approaches to improve image quality. In combination with appropriate decoding algorithms, these collimators permit a significant reduction of the time needed to register the projections used to make 3-D representations of the volumetric distribution of target's radiotracers. Simultaneously, they can be used to minimize artifacts and blurring arising when single pinhole collimators are used. Representation images are presented, which illustrate the use of these collimators. We also comment on the use of coded masks to attain tomographic resolution with a single projection, as discussed by some investigators since their introduction to obtain near-field images. We conclude this review by showing that the use of appropriate hardware and software tools adapted to conventional gamma-cameras can be of great help in obtaining relevant functional information in experiments using small animals. (author)

  7. Kite aerial photography for low-cost, ultra-high spatial resolution multi-spectral mapping of intertidal landscapes.

    Science.gov (United States)

    Bryson, Mitch; Johnson-Roberson, Matthew; Murphy, Richard J; Bongiorno, Daniel

    2013-01-01

    Intertidal ecosystems have primarily been studied using field-based sampling; remote sensing offers the ability to collect data over large areas in a snapshot of time that could complement field-based sampling methods by extrapolating them into the wider spatial and temporal context. Conventional remote sensing tools (such as satellite and aircraft imaging) provide data at limited spatial and temporal resolutions and relatively high costs for small-scale environmental science and ecologically-focussed studies. In this paper, we describe a low-cost, kite-based imaging system and photogrammetric/mapping procedure that was developed for constructing high-resolution, three-dimensional, multi-spectral terrain models of intertidal rocky shores. The processing procedure uses automatic image feature detection and matching, structure-from-motion and photo-textured terrain surface reconstruction algorithms that require minimal human input and only a small number of ground control points and allow the use of cheap, consumer-grade digital cameras. The resulting maps combine imagery at visible and near-infrared wavelengths and topographic information at sub-centimeter resolutions over an intertidal shoreline 200 m long, thus enabling spatial properties of the intertidal environment to be determined across a hierarchy of spatial scales. Results of the system are presented for an intertidal rocky shore at Jervis Bay, New South Wales, Australia. Potential uses of this technique include mapping of plant (micro- and macro-algae) and animal (e.g. gastropods) assemblages at multiple spatial and temporal scales.

  8. Facile and high spatial resolution ratio-metric luminescence thermal mapping in microfluidics by near infrared excited upconversion nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yu; Li, Shunbo; Wen, Weijia, E-mail: phwen@ust.hk [Department of Physics, KAUST-HKUST Joint Micro/Nanofluidic Laboratory, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon (Hong Kong); Cao, Wenbin [Nano Science and Technology Program, Department of Physics, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon (Hong Kong)

    2016-02-01

    A local area temperature monitor is important for precise control of chemical and biological processes in microfluidics. In this work, we developed a facile method to realize micron spatial resolution of temperature mapping in a microfluidic channel quickly and cost effectively. Based on the temperature dependent fluorescence emission of NaYF{sub 4}:Yb{sup 3+}, Er{sup 3+} upconversion nanoparticles (UCNPs) under near-infrared irradiation, ratio-metric imaging of UCNPs doped polydimethylsiloxane can map detailed temperature distribution in the channel. Unlike some reported strategies that utilize temperature sensitive organic dye (such as Rhodamine) to achieve thermal sensing, our method is highly chemically inert and physically stable without any performance degradation in long term operation. Moreover, this method can be easily scaled up or down, since the spatial and temperature resolution is determined by an optical imaging system. Our method supplied a simple and efficient solution for temperature mapping on a heterogeneous surface where usage of an infrared thermal camera was limited.

  9. Developing a CCD camera with high spatial resolution for RIXS in the soft X-ray range

    Science.gov (United States)

    Soman, M. R.; Hall, D. J.; Tutt, J. H.; Murray, N. J.; Holland, A. D.; Schmitt, T.; Raabe, J.; Schmitt, B.

    2013-12-01

    The Super Advanced X-ray Emission Spectrometer (SAXES) at the Swiss Light Source contains a high resolution Charge-Coupled Device (CCD) camera used for Resonant Inelastic X-ray Scattering (RIXS). Using the current CCD-based camera system, the energy-dispersive spectrometer has an energy resolution (E/ΔE) of approximately 12,000 at 930 eV. A recent study predicted that through an upgrade to the grating and camera system, the energy resolution could be improved by a factor of 2. In order to achieve this goal in the spectral domain, the spatial resolution of the CCD must be improved to better than 5 μm from the current 24 μm spatial resolution (FWHM). The 400 eV-1600 eV energy X-rays detected by this spectrometer primarily interact within the field free region of the CCD, producing electron clouds which will diffuse isotropically until they reach the depleted region and buried channel. This diffusion of the charge leads to events which are split across several pixels. Through the analysis of the charge distribution across the pixels, various centroiding techniques can be used to pinpoint the spatial location of the X-ray interaction to the sub-pixel level, greatly improving the spatial resolution achieved. Using the PolLux soft X-ray microspectroscopy endstation at the Swiss Light Source, a beam of X-rays of energies from 200 eV to 1400 eV can be focused down to a spot size of approximately 20 nm. Scanning this spot across the 16 μm square pixels allows the sub-pixel response to be investigated. Previous work has demonstrated the potential improvement in spatial resolution achievable by centroiding events in a standard CCD. An Electron-Multiplying CCD (EM-CCD) has been used to improve the signal to effective readout noise ratio achieved resulting in a worst-case spatial resolution measurement of 4.5±0.2 μm and 3.9±0.1 μm at 530 eV and 680 eV respectively. A method is described that allows the contribution of the X-ray spot size to be deconvolved from these worst-case resolution measurements, estimating the spatial resolution to be approximately 3.5 μm and 3.0 μm at 530 eV and 680 eV, well below the resolution limit of 5 μm required to improve the spectral resolution by a factor of 2.

  10. Quantifying hyporheic exchange at high spatial resolution using natural temperature variations along a first?order stream

    NARCIS (Netherlands)

    Westhoff, M.C.; Gooseff, M.N.; Bogaard, T.A.; Savenije, H.H.G.

    2011-01-01

    Hyporheic exchange is an important process that underpins stream ecosystem function, and there have been numerous ways to characterize and quantify exchange flow rates and hyporheic zone size. The most common approach, using conservative stream tracer experiments and 1?D solute transport modeling,

  11. Fingerprinting fluid sources in Troodos ophiolite complex orbicular glasses using high spatial resolution isotope and trace element geochemistry

    Science.gov (United States)

    Fonseca, Raúl O. C.; Kirchenbaur, Maria; Ballhaus, Chris; Münker, Carsten; Zirner, Aurelia; Gerdes, Axel; Heuser, Alexander; Botcharnikov, Roman; Lenting, Christoph

    2017-03-01

    The Troodos igneous complex (Cyprus) is a ca. 90 Ma old, well preserved supra-subduction zone ophiolite. Troodos is unique in that it shows evidence of fluid-saturation throughout the complex, from its base (i.e. podiform chromitites) to its uppermost units - the upper pillow lavas (UPL). However, it is unclear what the source of dissolved water in UPL tholeiites is, with possibilities including shallow seawater infiltration, assimilation of altered Troodos oceanic crust, recycled serpentinized oceanic crust, or subducted pelagic sediments. In order to identify and characterize these components we have carried out a detailed high-resolution study on tholeiitic lavas on orbicular structures and glasses from the UPL in Troodos. Basaltic orbicules were measured for their Sr-Nd-Hf-Pb isotope compositions, and in situ for their B isotopes using LA-MC-ICP-MS. UPL orbicules display a very narrow range in ɛ Nd and ɛ Hf (+7 to +8 and +13 to +15, respectively) indicating melting of a depleted mantle source. Lead isotopes, specifically 207Pb/204Pb vs. 206Pb/204Pb, form a mixing array with pelagic sediments. Furthermore, high-resolution characterization of individual orbicules revealed that UPL tholeiites display strong variability in 87Sr/86Sr (0.7039-0.7060) at the outcrop scale. Samples display δ11 B between -8.2 (± 0.5)‰ and +5.9 (± 1.1)‰ with an average B content of ca. 5 μg/g. Contrary to expectation, altered orbicules and their associated hyaloclastite matrixes display lower δ11 B (down to -10‰) and higher B contents (max. 200 μg/g) when compared to fresh glass. Furthermore, the orbicules studied here show little or no evidence of interaction with seawater, which is supported by their trace element contents and isotope compositions. When all isotope systems are taken into account, UPL lavas reflect melting of a depleted mantle source that was overprinted by hydrous sediment melts, and potentially, fluid-like subduction components that in part originate from serpentinized oceanic crust. Subsequent low-temperature alteration then drove δ11 B to lower values coupled with increased B uptake due to its adsorption into palagonite.

  12. Energy-selective neutron imaging with high spatial resolution and its impact on the study of crystalline-structured materials

    Science.gov (United States)

    Lehmann, E. H.; Peetermans, S.; Josic, L.; Leber, H.; van Swygenhoven, H.

    2014-01-01

    Crystalline-structured materials with preferentially large grains were investigated by means of energy-selective neutron imaging methods (transmission radiography and tomography) under the conditions of the best possible spatial resolution at the ICON facility, SINQ, and PSI. Because of the cold spectrum at that beam line, access to the Bragg diffraction features was possible even when the energy resolution of the used selector device was only 15%. Grains with a size below the detector resolution (approximately 25 μm) are not visible, and a quasi-homogeneous contrast variation is found when the neutron energy is varied.In the cases of welded stainless steel samples and rolled Al plates, we obtained structural information from a very short exposure of approximately 60 s. Tomographic examinations of these samples at suitable neutron energies qualitatively verified the radiographic findings by showing the same features in the bulk. Comparison to common electron backscatter diffraction (EBSD) investigations in selected regions of the samples provided a complete verification of the neutron-image data with respect to the grain size and the different grain orientations. The method of energy-selective neutron imaging provides an easy and straightforward approach for non-invasive material research that can be performed without any sample preparation if the most suitable neutron energy is chosen. Further studies will be necessary to extend the experimental data base to other materials with different crystal structures and grain sizes. A comparison to diffraction data will enhance the quantitative value of the investigations.

  13. An approach for mapping large-area impervious surfaces: Synergistic use of Landsat-7 ETM+ and high spatial resolution imagery

    Science.gov (United States)

    Yang, Limin; Huang, Chengquan; Homer, Collin G.; Wylie, Bruce K.; Coan, Michael

    2003-01-01

    A wide range of urban ecosystem studies, including urban hydrology, urban climate, land use planning, and resource management, require current and accurate geospatial data of urban impervious surfaces. We developed an approach to quantify urban impervious surfaces as a continuous variable by using multisensor and multisource datasets. Subpixel percent impervious surfaces at 30-m resolution were mapped using a regression tree model. The utility, practicality, and affordability of the proposed method for large-area imperviousness mapping were tested over three spatial scales (Sioux Falls, South Dakota, Richmond, Virginia, and the Chesapeake Bay areas of the United States). Average error of predicted versus actual percent impervious surface ranged from 8.8 to 11.4%, with correlation coefficients from 0.82 to 0.91. The approach is being implemented to map impervious surfaces for the entire United States as one of the major components of the circa 2000 national land cover database.

  14. Investigating the effect of pixel size of high spatial resolution FTIR imaging for detection of colorectal cancer

    Science.gov (United States)

    Lloyd, G. R.; Nallala, J.; Stone, N.

    2016-03-01

    FTIR is a well-established technique and there is significant interest in applying this technique to medical diagnostics e.g. to detect cancer. The introduction of focal plane array (FPA) detectors means that FTIR is particularly suited to rapid imaging of biopsy sections as an adjunct to digital pathology. Until recently however each pixel in the image has been limited to a minimum of 5.5 µm which results in a comparatively low magnification image or histology applications and potentially the loss of important diagnostic information. The recent introduction of higher magnification optics gives image pixels that cover approx. 1.1 µm. This reduction in image pixel size gives images of higher magnification and improved spatial detail can be observed. However, the effect of increasing the magnification on spectral quality and the ability to discriminate between disease states is not well studied. In this work we test the discriminatory performance of FTIR imaging using both standard (5.5 µm) and high (1.1 µm) magnification for the detection of colorectal cancer and explore the effect of binning to degrade high resolution images to determine whether similar diagnostic information and performance can be obtained using both magnifications. Results indicate that diagnostic performance using high magnification may be reduced as compared to standard magnification when using existing multivariate approaches. Reduction of the high magnification data to standard magnification via binning can potentially recover some of the lost performance.

  15. On the creation of high spatial resolution imaging spectroscopy data from multi-temporal low spatial resolution imagery

    Science.gov (United States)

    Yao, Wei; van Aardt, Jan; Messinger, David

    2017-05-01

    The Hyperspectral Infrared Imager (HyspIRI) mission aims to provide global imaging spectroscopy data to the benefit of especially ecosystem studies. The onboard spectrometer will collect radiance spectra from the visible to short wave infrared (VSWIR) regions (400-2500 nm). The mission calls for fine spectral resolution (10 nm band width) and as such will enable scientists to perform material characterization, species classification, and even sub-pixel mapping. However, the global coverage requirement results in a relatively low spatial resolution (GSD 30m), which restricts applications to objects of similar scales. We therefore have focused on the assessment of sub-pixel vegetation structure from spectroscopy data in past studies. In this study, we investigate the development or reconstruction of higher spatial resolution imaging spectroscopy data via fusion of multi-temporal data sets to address the drawbacks implicit in low spatial resolution imagery. The projected temporal resolution of the HyspIRI VSWIR instrument is 15 days, which implies that we have access to as many as six data sets for an area over the course of a growth season. Previous studies have shown that select vegetation structural parameters, e.g., leaf area index (LAI) and gross ecosystem production (GEP), are relatively constant in summer and winter for temperate forests; we therefore consider the data sets collected in summer to be from a similar, stable forest structure. The first step, prior to fusion, involves registration of the multi-temporal data. A data fusion algorithm then can be applied to the pre-processed data sets. The approach hinges on an algorithm that has been widely applied to fuse RGB images. Ideally, if we have four images of a scene which all meet the following requirements - i) they are captured with the same camera configurations; ii) the pixel size of each image is x; and iii) at least r2 images are aligned on a grid of x/r - then a high-resolution image, with a pixel size of x/r, can be reconstructed from the multi-temporal set. The algorithm was applied to data from NASA's classic Airborne Visible and Infrared Imaging Spectrometer (AVIRIS-C; GSD 18m), collected between 2013-2015 (summer and fall) over our study area (NEON's Southwest Pacific Domain; Fresno, CA) to generate higher spatial resolution imagery (GSD 9m). The reconstructed data set was validated via comparison to NEON's imaging spectrometer (NIS) data (GSD 1m). The results showed that algorithm worked well with the AVIRIS-C data and could be applied to the HyspIRI data.

  16. Assessing water stress of desert Tamarugo trees using in situ data and very high spatial resolution remote sensing

    National Research Council Canada - National Science Library

    Chávez Oyanadel, R.O; Clevers, J.G.P.W; Herold, M; Acevedo, E; Ortiz, M

    2013-01-01

    .... One such species is the tree Prosopis tamarugo Phil. Because Tamarugo completely depends on groundwater, it is being threatened by the high water demand from the Chilean mining industry and the human consumption...

  17. Assessing water stress of desert Tamarugo trees using in situ data and very high spatial resolution remote sensing

    NARCIS (Netherlands)

    Chávez Oyanadel, R.O.; Clevers, J.G.P.W.; Herold, M.; Acevedo, E.; Ortiz, M.

    2013-01-01

    The hyper-arid Atacama Desert is one of the most extreme environments for life and only few species have evolved to survive its aridness. One such species is the tree Prosopis tamarugo Phil. Because Tamarugo completely depends on groundwater, it is being threatened by the high water demand from the

  18. High-spatial-resolution electron density measurement by Langmuir probe for multi-point observations using tiny spacecraft

    Science.gov (United States)

    Hoang, H.; Røed, K.; Bekkeng, T. A.; Trondsen, E.; Clausen, L. B. N.; Miloch, W. J.; Moen, J. I.

    2017-11-01

    A method for evaluating electron density using a single fixed-bias Langmuir probe is presented. The technique allows for high-spatio-temporal resolution electron density measurements, which can be effectively carried out by tiny spacecraft for multi-point observations in the ionosphere. The results are compared with the multi-needle Langmuir probe system, which is a scientific instrument developed at the University of Oslo comprising four fixed-bias cylindrical probes that allow small-scale plasma density structures to be characterized in the ionosphere. The technique proposed in this paper can comply with the requirements of future small-sized spacecraft, where the cost-effectiveness, limited space available on the craft, low power consumption and capacity for data-links need to be addressed. The first experimental results in both the plasma laboratory and space confirm the efficiency of the new approach. Moreover, detailed analyses on two challenging issues when deploying the DC Langmuir probe on a tiny spacecraft, which are the limited conductive area of the spacecraft and probe surface contamination, are presented in the paper. It is demonstrated that the limited conductive area, depending on applications, can either be of no concern for the experiment or can be resolved by mitigation methods. Surface contamination has a small impact on the performance of the developed probe.

  19. Fusion of satellite-based imager and sounder data to construct supplementary high spatial resolution narrowband IR radiances

    Science.gov (United States)

    Weisz, Elisabeth; Baum, Bryan A.; Menzel, W. Paul

    2017-07-01

    Polar-orbiting weather satellite platforms generally include an imager and a sounder. With a data fusion method that uses these sensors, we demonstrate the ability to construct infrared (IR) absorption narrowband radiances at imager resolution. While a sensor such as MODIS has multiple IR absorption bands, the current visible infrared imaging radiometer suite (VIIRS) imager has only IR window bands. We show fusion results for IR radiances at 4.52 μm (CO2), 6.72 μm (H2O), and 13.94 μm (CO2) by comparing MODIS observed and constructed radiances for these bands. Both regional and global results are analyzed, with radiance differences tending to be fairly low and unbiased. Similar bands are constructed from VIIRS and CrIS data, with regional and global results shown. With this approach, it will be possible to improve continuity in derived cloud products over the generations of polar-orbiting weather satellite sensors and continue applications that require IR absorption bands.

  20. Using High Spatial Resolution Satellite Imagery to Map Forest Burn Severity Across Spatial Scales in a Pine Barrens Ecosystem

    Science.gov (United States)

    Meng, Ran; Wu, Jin; Schwager, Kathy L.; Zhao, Feng; Dennison, Philip E.; Cook, Bruce D.; Brewster, Kristen; Green, Timothy M.; Serbin, Shawn P.

    2017-01-01

    As a primary disturbance agent, fire significantly influences local processes and services of forest ecosystems. Although a variety of remote sensing based approaches have been developed and applied to Landsat mission imagery to infer burn severity at 30 m spatial resolution, forest burn severity have still been seldom assessed at fine spatial scales (less than or equal to 5 m) from very-high-resolution (VHR) data. We assessed a 432 ha forest fire that occurred in April 2012 on Long Island, New York, within the Pine Barrens region, a unique but imperiled fire-dependent ecosystem in the northeastern United States. The mapping of forest burn severity was explored here at fine spatial scales, for the first time using remotely sensed spectral indices and a set of Multiple Endmember Spectral Mixture Analysis (MESMA) fraction images from bi-temporal - pre- and post-fire event - WorldView-2 (WV-2) imagery at 2 m spatial resolution. We first evaluated our approach using 1 m by 1 m validation points at the sub-crown scale per severity class (i.e. unburned, low, moderate, and high severity) from the post-fire 0.10 m color aerial ortho-photos; then, we validated the burn severity mapping of geo-referenced dominant tree crowns (crown scale) and 15 m by 15 m fixed-area plots (inter-crown scale) with the post-fire 0.10 m aerial ortho-photos and measured crown information of twenty forest inventory plots. Our approach can accurately assess forest burn severity at the sub-crown (overall accuracy is 84% with a Kappa value of 0.77), crown (overall accuracy is 82% with a Kappa value of 0.76), and inter-crown scales (89% of the variation in estimated burn severity ratings (i.e. Geo-Composite Burn Index (CBI)). This work highlights that forest burn severity mapping from VHR data can capture heterogeneous fire patterns at fine spatial scales over the large spatial extents. This is important since most ecological processes associated with fire effects vary at the less than 30 m scale and VHR approaches could significantly advance our ability to characterize fire effects on forest ecosystems.

  1. High spatial resolution grain orientation and strain mapping in thin films using polychromatic submicron X-ray diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Tamura, N.; MacDowell, A.A.; Celestre, R.S.; Padmore, H.A.; Valek, B.C.; Bravman, J.C.; Spolenak, R.; Brown, W.L.; Marieb, T.; Fujimoto, H.; Batterman, B.W.; Patel, J.R.

    2002-03-26

    The availability of high brilliance synchrotron sources, coupled with recent progress in achromatic focusing optics and large area 2D detector technology, have allowed us to develop an X-ray synchrotron technique capable of mapping orientation and strain/stress in polycrystalline thin films with submicron spatial resolution. To demonstrate the capabilities of this instrument, we have employed it to study the microstructure of aluminum thin film structures at the granular and subgranular level. Owing to the relatively low absorption of X-rays in materials, this technique can be used to study passivated samples, an important advantage over most electron probes given the very different mechanical behavior of buried and unpassivated materials.

  2. High Spatial Resolution Grain Orientation and Strain Mapping in Thin Films using Polychromatic Submicron X-ray Diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Patel, Jamshed R.

    2002-06-14

    The availability of high brilliance synchrotron sources, coupled with recent progress in achromatic focusing optics and large area 2D detector technology, have allowed us to develop a X-ray synchrotron technique capable of mapping orientation and strain/stress in polycrystalline thin films with submicron spatial resolution. To demonstrate the capabilities of this instrument, we have employed it to study the microstructure of aluminum thin film structures at the granular and subgranular level. Owing to the relatively low absorption of X-rays in materials, this technique can be used to study passivated samples, an important advantage over most electron probes given the very different mechanical behavior of buried and unpassivated materials.

  3. Cross calibration between XRF and ICP-MS for high spatial resolution analysis of ombrotrophic peat cores for palaeoclimatic studies.

    Science.gov (United States)

    Poto, Luisa; Gabrieli, Jacopo; Crowhurst, Simon; Agostinelli, Claudio; Spolaor, Andrea; Cairns, Warren R L; Cozzi, Giulio; Barbante, Carlo

    2015-01-01

    Ombrotrophic peatlands are remarkable repositories of high-quality climatic signals because their only source of nutrients is precipitation. Although several analytical techniques are available for analysing inorganic components in peat samples, they generally provide only low-resolution data sets. Here we present a new analytical approach for producing high-resolution data on main and trace elements from ombrotrophic peat cores. Analyses were carried out on a 7-m-long peat core collected from Danta di Cadore, North-Eastern Italy (46° 34' 16″ N, 12° 29' 58″ E). Ca, Ti, Cr, Fe, Cu, Zn, Ga, Sr, Y, Cd, Ba and Pb were detected at a resolution of 2.5 mm with a non-destructive X-ray fluorescence core scanner (XRF-CS). Calibration and quantification of the XRF-CS intensities was obtained using collision reaction cell inductively coupled plasma quadruple mass spectrometry (CRC-ICP-QMS). CRC-ICP-QMS measurements were carried out on discrete samples at a resolution of 1 cm, after dissolution of 150-mg aliquots with 9 ml HNO3 and 1 ml HF at 220 °C in a microwave system. We compare qualitative XRF-CS and quantitative CRC-ICP-MS data and, however the several sources of variability of the data, develop a robust statistical approach to determine the R (2) and the coefficient of a simple regression model together with confidence intervals. Perfect positive correlations were estimated for Cd, Cr, Pb, Sr, Ti and Zn; high positive correlations for Ba (0.8954), Y (0.7378), Fe (0.7349) and Cu (0.7028); while moderate positive correlations for Ga (0.5951) and Ca (0.5435). With our results, we demonstrate that XRF scanning techniques can be used, together with other well-established geochemical techniques (such as ICP-MS), to produce high-resolution (up to 2.5 mm) quantitative data from ombrotrophic peat bog cores.

  4. Inferring urban household socio-economic conditions in Mafikeng, South Africa, using high spatial resolution satellite imagery

    OpenAIRE

    Christopher Munyati; Gaolatlhe L. Motholo

    2014-01-01

    Updated household socio-economic information is necessary for planning the delivery of municipal services, particularly for cities in third world countries. The repetitive coverage of satellite imagery provides a possibility for sourcing and frequently updating information on household socio-economic conditions in urban landscapes. This paper examines the potential use of satellite imagery in inferring urban household socio-economic variables, using two high-resolution images of 2001 and 2010...

  5. Inferring urban household socio-economic conditions in Mafikeng, South Africa, using high spatial resolution satellite imagery

    Directory of Open Access Journals (Sweden)

    Christopher Munyati

    2014-01-01

    Full Text Available Updated household socio-economic information is necessary for planning the delivery of municipal services, particularly for cities in third world countries. The repetitive coverage of satellite imagery provides a possibility for sourcing and frequently updating information on household socio-economic conditions in urban landscapes. This paper examines the potential use of satellite imagery in inferring urban household socio-economic variables, using two high-resolution images of 2001 and 2010. Manual image interpretation was employed in deducing selected socio-economic variables that are utilised in census enumerations in South Africa, at four suburbs in Mafikeng. Of the three socio-economic variables that were examined (type of main dwelling, toilet facilities, and energy source for cooking, type of dwelling could more readily be deduced from the high-resolution imagery. Identified change in number of formal and informal houses indicated potential of satellite imagery in monitoring third world setting urban sprawl and the associated growth in informal settlements due to migration, among other factors. Satellite imagery appears useful as a supplementary source of socio-economic data to municipal authorities, for periods between regular censuses.

  6. Crossed Optical Fiber Sensor Arrays for High-Spatial-Resolution Sensing: Application to Dissolved Oxygen Concentration Measurements

    Directory of Open Access Journals (Sweden)

    M. Veronica Rigo

    2012-01-01

    Full Text Available Optical fiber sensors using luminescent probes located along an optical fiber in the cladding of this fiber are of great interest for monitoring physical and chemical properties in their environment. The interrogation of a luminophore with a short laser pulse propagating through the fiber core allows for the measurement of the location of these luminophores. To increase the spatial resolution of such a measurements and to measure multiple analytes and properties in a confined space, a crossed optical fiber sensing platform can be employed. Here we describe the application of this platform to measuring the concentration of dissolved oxygen. The sensor is based on luminescence quenching of a ruthenium complex immobilized in a highly crosslinked film and covalently attached to the optical fibers. Both luminescence-intensity and luminescence-lifetime changes of the sensor molecules in response to changes in the concentration of oxygen dissolved in water are reported. For luminescence-intensity measurements, a second adjacent sensor region is employed as reference to account for laser pulse energy fluctuations. Enhanced quenching response in water is demonstrated by the use of organically modified poly(ethylene glycol precursors, which increase the hydrophobicity of the film surface.

  7. Three-dimensional, multifluid, high spatial resolution MHD model studies of the solar wind interaction with Mars

    Science.gov (United States)

    Najib, Dalal; Nagy, Andrew F.; Tóth, Gábor; Ma, Yingjuan

    2011-05-01

    Our newly developed 3-D, multifluid MHD model is used to study the interaction of the solar wind with Mars. This model is based on the BATS-R-US code, using a spherical grid and a radial resolution equal to 10 km in the ionospheric regions. We solve separate continuity, momentum, and energy equations for each ion fluid and run our model for both solar minimum and maximum conditions. We obtain asymmetric densities, velocities, and magnetic pileup in the plane containing both the direction of the solar wind and the convective electric field. These asymmetries are the result of the decoupling of the individual ions; therefore, our model is able to account for the respective dynamics of the ions and to show new physical processes that could not be observed by the single-fluid model. Our results are consistent with the measured bow shock and magnetic pileup locations and with the Viking-observed ion densities. We also compute the escape fluxes for both solar minimum and solar maximum conditions and compare them to the single-fluid results and the observed values from Mars Express.

  8. High spatial resolution satellite observations for validation of MODIS land products: IKONOS observations acquired under the NASA scientific data purchase.

    Science.gov (United States)

    Jeffrey T. Morisette; Jaime E. Nickeson; Paul Davis; Yujie Wang; Yuhong Tian; Curtis E. Woodcock; Nikolay Shabanov; Matthew Hansen; Warren B. Cohen; Doug R. Oetter; Robert E. Kennedy

    2003-01-01

    Phase 1I of the Scientific Data Purchase (SDP) has provided NASA investigators access to data from four different satellite and airborne data sources. The Moderate Resolution Imaging Spectrometer (MODIS) land discipline team (MODLAND) sought to utilize these data in support of land product validation activities with a lbcus on tile EOS Land Validation Core Sites. These...

  9. Pit lake lime dosing: Assessment of the performance of the treatment based on a high-spatial resolution AUV survey

    Science.gov (United States)

    Delgado, Jordi; García-Morrondo, David; Cereijo-Arango, José Luis; Muñoz-Ibáñez, Andrea; Grande-García, Elisa; Rodríguez-Cedrún, Borja; Juncosa-Rivera, Ricardo

    2016-04-01

    The acidity of mine waters is typically corrected with passive (where possible) and/or active (i.e. chemical additions) systems. In the case of active treatments, lime dosing is a widespread technique due to the relatively ease of implementation and reduced operational costs. While neutralization of acidic waters is routinely performed in circulating water treatment facilities this is not so simple in open waters (e.g. pit lakes) because an efficient treatment requires the adequate distribution of the alkaline reagents throughout the volume of interest. To cope with this problem, a number of technical approaches have been proposed including active stirring (bubbling, etc.), surface spread diffusion, etc. In the early times of flooding of the Meirama mine, managers considered the necessity of lime dosing to correct the initially acidic mine waters. However, lake evolution proved that liming was not necessary and it was desirable to allow a reasonably unmanned evolution of the reclaimed system. In order to ensure that the lime dosing system is in good operative conditions in case of necessity, according to a prescribed time schedule to time mine managers put it in operation. That give us the opportunity to perform a large-scale "tracer" experiment useful to test the efficiency of wet lime dosing in a large water body. Dry lime, which is kept in a storage silo, is directly dosed over the channel of a small stream discharging in the lake. Therefore, stream water becomes saturated with lime and a pH of approximately 12.3. Stream water flows in cascade to the lake so that a certain potential and kinetic energy transfer is delivered to the lake. That promotes currents that enhance the re-distribution of the alkalinity load. In order to check for the distribution of alkaline water in the top body of the lake, an autonomous underwater vehicle (Yellow Spring Instruments Inc. EcoMapper AUV) was used. This device allows for the high- frequency simultaneous measurement of a water quality parameters (temperature, pH, electrical conductivity, dissolved oxygen, redox, turbidity and concentration of chlorophyll) according to prescribed trajectories at constant or variable depth. In the present study, depth was fixed at 1 m below the surface of the lake and two surveys were performed in two consecutive days. Results indicate that the efficiency of lime dosing is limited and, under windy conditions (i.e. when wind-transferred energy exceeds that of the currents associated with the liming system and others present in the lake), liming tends to preferentially concentrate at the leeward side of the lake.

  10. Healthy Weight

    Science.gov (United States)

    ... Weight Gain Losing Weight Getting Started Improving Your Eating Habits Keeping It Off Healthy Eating for a Healthy ... or "program". It's about lifestyle changes in daily eating and exercise habits. Success Stories They did it. So can you! ...

  11. Weighted Clustering

    DEFF Research Database (Denmark)

    Ackerman, Margareta; Ben-David, Shai; Branzei, Simina

    2012-01-01

    We investigate a natural generalization of the classical clustering problem, considering clustering tasks in which different instances may have different weights.We conduct the first extensive theoretical analysis on the influence of weighted data on standard clustering algorithms in both...... the partitional and hierarchical settings, characterizing the conditions under which algorithms react to weights. Extending a recent framework for clustering algorithm selection, we propose intuitive properties that would allow users to choose between clustering algorithms in the weighted setting and classify...

  12. Weighted LCS

    Science.gov (United States)

    Amir, Amihood; Gotthilf, Zvi; Shalom, B. Riva

    The Longest Common Subsequence (LCS) of two strings A and B is a well studied problem having a wide range of applications. When each symbol of the input strings is assigned a positive weight the problem becomes the Heaviest Common Subsequence (HCS) problem. In this paper we consider a different version of weighted LCS on Position Weight Matrices (PWM). The Position Weight Matrix was introduced as a tool to handle a set of sequences that are not identical, yet, have many local similarities. Such a weighted sequence is a 'statistical image' of this set where we are given the probability of every symbol's occurrence at every text location. We consider two possible definitions of LCS on PWM. For the first, we solve the weighted LCS problem of z sequences in time O(zn z + 1). For the second, we prove \\cal{NP}-hardness and provide an approximation algorithm.

  13. Weighted approximation with varying weight

    CERN Document Server

    Totik, Vilmos

    1994-01-01

    A new construction is given for approximating a logarithmic potential by a discrete one. This yields a new approach to approximation with weighted polynomials of the form w"n"(" "= uppercase)P"n"(" "= uppercase). The new technique settles several open problems, and it leads to a simple proof for the strong asymptotics on some L p(uppercase) extremal problems on the real line with exponential weights, which, for the case p=2, are equivalent to power- type asymptotics for the leading coefficients of the corresponding orthogonal polynomials. The method is also modified toyield (in a sense) uniformly good approximation on the whole support. This allows one to deduce strong asymptotics in some L p(uppercase) extremal problems with varying weights. Applications are given, relating to fast decreasing polynomials, asymptotic behavior of orthogonal polynomials and multipoint Pade approximation. The approach is potential-theoretic, but the text is self-contained.

  14. Weighted Hypernetworks

    CERN Document Server

    Zhu, Xin-Yun

    2014-01-01

    Complex network theory has been used to study complex systems. However, many real life systems involve multiple kinds of objects . They can't be described by simple graphs. In order to provide complete information of these systems, we extend the concept of evolving models of complex networks to hypernetworks. In this work, we firstly propose a non-uniform hypernetwork model with attractiveness, and obtain the stationary average hyperdegree distribution of the non-uniform hypernetwork. Furthermore, we develop a model for weighted hypernetworks that couples the establishment of new hyperedges and nodes and the weights' dynamical evolution. We obtain the stationary average hyperdegree distribution by using the hyperdegree distribution of the hypernetwork model with attractiveness. In particular, the model yields a nontrivial time evolution of nodes' properties and scale-free behavior for the hyperdegree distribution. It is expected that our work may give help to the study of the hypernetworks in real-world syste...

  15. The Design and Implementation in $0.13\\mu m$ CMOS of an Algorithm Permitting Spectroscopic Imaging with High Spatial Resolution for Hybrid Pixel Detectors

    CERN Document Server

    Ballabriga, Rafael; Vilasís-Cardona, Xavier

    2009-01-01

    Advances in pixel detector technology are opening up new possibilities in many fields of science. Modern High Energy Physics (HEP) experiments use pixel detectors in tracking systems where excellent spatial resolution, precise timing and high signal-to-noise ratio are required for accurate and clean track reconstruction. Many groups are working worldwide to adapt the hybrid pixel technology to other fields such as medical X-ray radiography, protein structure analysis or neutron imaging. The Medipix3 chip is a 256x256 channel hybrid pixel detector readout chip working in Single Photon Counting Mode. It has been developed with a new front-end architecture aimed at eliminating the spectral distortion produced by charge diffusion in highly segmented semiconductor detectors. In the new architecture neighbouring pixels communicate with one another. Charges can be summed event-by-event and the incoming quantum can be assigned as a single hit to the pixel with the biggest charge deposit. In the case where incoming X-...

  16. Improved Monitoring of Bio-Optical Processes in Coastal and Inland Waters Using High Spatial Resolution Channels on SNPP-VIIRS Sensor

    Science.gov (United States)

    2013-07-17

    region of the spectrum, while also backscattered in the presence of suspended particles, are heavily influenced by absorption of phytoplankton cells... components have a known effect, information about the variable aerosol contribution and Rayleigh-aerosol interactions (La, Lra) to the TOA reflectance (Lt

  17. Isotropic high-spatial-resolution contrast-enhanced 3.0-T MR angiography in patients suspected of having renal artery stenosis.

    Science.gov (United States)

    Kramer, Ulrich; Wiskirchen, Jakub; Fenchel, Michael C; Seeger, Achim; Laub, Gerhard; Tepe, Gunnar; Finn, J Paul; Claussen, Claus D; Miller, Stephan

    2008-04-01

    The purpose of this study was to prospectively evaluate the diagnostic performance of contrast material-enhanced magnetic resonance (MR) angiography performed at 3 T for assessment of renal artery stenosis (RAS) by using parallel acquisition techniques with high acceleration factors and with digital subtraction angiography (DSA) as the reference standard. The study was institutional review board approved, and written informed consent was obtained from all patients. Twenty-nine patients (18 men, 11 women; mean age, 57.1 years +/- 14.3 [standard deviation]) suspected of having RAS underwent MR angiography. Images were evaluated qualitatively and quantitatively. The interobserver variability, sensitivity, specificity, and positive and negative predictive values of 3-T MR angiography, as compared with DSA (performed in 15 patients), were calculated. All examinations yielded good or excellent image quality. The sensitivity and specificity of MR angiography in grading significant (>75%) stenosis were 94% and 96%, respectively. Owing to its high sensitivity, contrast-enhanced 3-T MR angiography can be used reliably to exclude RAS and can serve as a useful screening method in the diagnostic work-up of patients with arterial hypertension.

  18. An ultra-clean technique for accurately analysing Pb isotopes and heavy metals at high spatial resolution in ice cores with sub-pg g(-1) Pb concentrations.

    Science.gov (United States)

    Burn, Laurie J; Rosman, Kevin J R; Candelone, Jean-Pierre; Vallelonga, Paul; Burton, Graeme R; Smith, Andrew M; Morgan, Vin I; Barbante, Carlo; Hong, Sungmin; Boutron, Claude F

    2009-02-23

    Measurements of Pb isotope ratios in ice containing sub-pg g(-1) concentrations are easily compromised by contamination, particularly where limited sample is available. Improved techniques are essential if Antarctic ice cores are to be analysed with sufficient spatial resolution to reveal seasonal variations due to climate. This was achieved here by using stainless steel chisels and saws and strict protocols in an ultra-clean cold room to decontaminate and section ice cores. Artificial ice cores, prepared from high purity water were used to develop and refine the procedures and quantify blanks. Ba and In, two other important elements present at pg g(-1) and fg g(-1) concentrations in Polar ice, were also measured. The final blank amounted to 0.2+/-0.2 pg of Pb with (206)Pb/(207)Pb and (208)Pb/(207)Pb ratios of 1.16+/-0.12 and 2.35+/-0.16, respectively, 1.5+/-0.4 pg of Ba and 0.6+/-2.0 fg of In, most of which probably originates from abrasion of the steel saws by the ice. The procedure was demonstrated on a Holocene Antarctic ice core section and was shown to contribute blanks of only approximately 5%, approximately 14% and approximately 0.8% to monthly resolved samples with respective Pb, Ba and In concentrations of 0.12 pg g(-1), 0.3 pg g(-1) and 2.3 fg g(-1). Uncertainties in the Pb isotopic ratio measurements were degraded by only approximately 0.2%.

  19. High Spatial Resolution Thermal Remote Sensing of the Urban Heat Island Effect: Assessment of Risks to Human Health and Development of Mitigation Strategies for Sustainable Cities

    Science.gov (United States)

    Quattrochi, Dale A.; Luvall, Jeffrey C.; Rickman, Douglas L.; Estes, Maurice G., Jr.; Laymon, Charles A.; Crosson, William; Howell, Burgess F.; Gillani, Noor V.; Arnold, James E. (Technical Monitor)

    2002-01-01

    The growth of cities, both in population and in areal extent, appears as an inexorable process. Urbanization continues at a rapid rate, and it is estimated that by the year 2025, 80% of the world's population will live in cities. One of the more egregious side effects of urbanization is the deterioration in air quality as a result of increased vehicular traffic, industrialization and related activities. In the United States alone, under the more stringent air quality guidelines established by the U.S. Environmental Protection Agency (EPA) in 1997, nearly 300 counties in 34 states will not meet the new air quality standards for ground level ozone. The mitigation of one the physical/environmental characteristics of urbanization known as the urban heat island (UHI) effect, is now being looked at more closely as a possible way to bring down ground level ozone levels in cities and assist states in improving air quality. The UHI results from the replacement of "natural" land covers (e.g., trees, grass) with urban land surface types, such as pavement and buildings. Heat stored in these surfaces is released into the air and results in a "dome" of elevated air temperatures that presides over cities. The effect of this dome of elevated air temperatures is known as the UHI, which is most prevalent about 2-3 hours after sunset on days with intense solar radiation and calm winds. Given the local and regional impacts of the UHI, there are significant potential affects on human health, particularly as related to heat stress and ozone on body temperature regulation and on the cardiovascular and respiratory systems. In this study we are using airborne and satellite remote sensing data to analyze how differences in the urban landscape influence or drive the development of the UHI over four U.S. cities. Additionally, we are assessing what the potential impact is on risks to human health, and developing mitigation strategies to make urban areas more environmentally sustainable.

  20. Lightning risk assessment at a high spatial resolution using the resident sub-district scale: A case study in Beijing metropolitan areas

    OpenAIRE

    Hu, Hai Bo; Li, Jing Xiao

    2016-01-01

    Lightning risk indexes identifying the potential number of dangerous lightning events (NDLEs) and ground sensitivity to lightning in resident sub-districts of Beijing metropolitan areas have been unprecedentedly estimated on a 5 m resolution grid. The gridded cloud to ground (CG) lightning stroke density was used in the NDLE calculation, on account of multiple contacts formed by CG lightning flash multiplicity. Meanwhile, in the NDLE estimates, the critical CG stroke gridded densities ...

  1. Design, Construction, and Initial Test of High Spatial Resolution Thermometry Arrays for Detection of Surface Temperature Profiles on SRF Cavities in Super Fluid Helium

    Energy Technology Data Exchange (ETDEWEB)

    Ari Palczewski, Rongli Geng, Grigory Eremeev

    2011-07-01

    We designed and built two high resolution (0.6-0.55mm special resolution [1.1-1.2mm separation]) thermometry arrays prototypes out of the Allen Bradley 90-120 ohm 1/8 watt resistor to measure surface temperature profiles on SRF cavities. One array was designed to be physically flexible and conform to any location on a SRF cavity; the other was modeled after the common G-10/stycast 2850 thermometer and designed to fit on the equator of an ILC (Tesla 1.3GHz) SRF cavity. We will discuss the advantages and disadvantages of each array and their construction. In addition we will present a case study of the arrays performance on a real SRF cavity TB9NR001. TB9NR001 presented a unique opportunity to test the performance of each array as it contained a dual (4mm separation) cat eye defect which conventional methods such as OST (Oscillating Superleak second-sound Transducers) and full coverage thermometry mapping were unable to distinguish between. We will discuss the new arrays ability to distinguish between the two defects and their preheating performance.

  2. High spatial resolution mapping of the Cerrado's land cover and land use types in the priority area for conservation Chapada da Contagem, Brazil.

    Science.gov (United States)

    Ribeiro, F.; Roberts, D. A.; Davis, F. W.; Antunes Daldegan, G.; Nackoney, J.; Hess, L. L.

    2016-12-01

    The Brazilian savanna, Cerrado, is the second largest biome over South America and the most floristically diverse savanna in the world. This biome is considered a conservation hotspot in respect to its biodiversity importance and rapid transformation of its landscape. The Cerrado's natural vegetation has been severely transformed by agriculture and pasture activities. Currently it is the main agricultural frontier in Brazil and one of the most threatened Brazilian biomes. This scenario results in environmental impacts such as ecosystems fragmentation as well as losses in connectivity, biodiversity and gene flow, changes in the microclimate and energy, carbon and nutrients cycles, among others. The Priority Areas for Conservation is a governmental program from Brazil that identifies areas with high conservation priority. One of this program's recommendation is a natural vegetation map including their major ecosystem classes. This study aims to generate more precise information for the Cerrado's vegetation. The main objective of this study is to identify which ecosystems are being prioritized and/or threatened by land use, refining information for further protection. In order to test methods, the priority area for conservation Chapada da Contagem was selected as the study site. This area is ranked as "extremely high priority" by the government and is located in the Federal District and Goias State, Brazil. Satellites with finer spatial resolution may improve the classification of the Cerrado's vegetation. Remote sensing methods and two criteria were tested using RapidEye 3A imagery (5m spatial resolution) collected in 2014 in order to classify the Cerrado's major land cover types of this area, as well as its land use. One criterion considers the Cerrado's major terrestrial ecosystems, which are divided into forest, savanna and grassland. The other involves scaling it down to the major physiognomic groups of each ecosystem. Other sources of environmental dataset such as soil type and slope were incorporated into this test as they are correlated with the ecosystems and physiognomies presence. A Decision Tree was used to map the land cover and land use types present in the region and demonstrated to have an effective result due to the map's high accuracy and incorporation of environmental dataset.

  3. High spatial resolution geochemistry and textural characteristics of 'microtektite' glass spherules in proximal Cretaceous-Paleogene sections: Insights into glass alteration patterns and precursor melt lithologies

    NARCIS (Netherlands)

    Belza, J.; Goderis, S.; Smit, J.; Vanhaecke, F.; Baert, K.; Terryn, H.; Claeys, P.

    2015-01-01

    Using laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS), we have conducted spatially resolved trace element analysis on fresh, unaltered microtektite glasses linked to the Cretaceous-Paleogene (K-Pg) boundary Chicxulub crater and on their surrounding alteration phases. This

  4. Fusion of Landsat-8/OLI and GOCI Data for Hourly Mapping of Suspended Particulate Matter at High Spatial Resolution: A Case Study in the Yangtze (Changjiang Estuary

    Directory of Open Access Journals (Sweden)

    Yanqun Pan

    2018-01-01

    Full Text Available Suspended particulate matter (SPM concentrations ([SPM] in the Yangtze estuary, which has third-order bifurcations and four outlets, exhibit large spatial and temporal variations. Studying the characteristics of these variations in [SPM] is important for understanding sediment transport and pollutant diffusion in the estuary as well as for the construction of port and estuarine engineering structures. The 1-h revisit frequency of the Geostationary Ocean Color Imager (GOCI sensor and the 30-m spatial resolution of the Landsat 8 Operational Land Imager (L8/OLI provide a new opportunity to study the large spatial and temporal variations in the [SPM] in the Yangtze estuary. In this study, [SPM] images with a temporal resolution of 1 h and a spatial resolution of 30 m are generated through the product-level fusion of [SPM] data derived from L8/OLI and GOCI images using the Spatial and Temporal Adaptive Reflectance Fusion Model (STARFM. The results show that the details and accuracy of the spatial and temporal variations are maintained well in the [SPM] images that are predicted based on the fused images. Compared to the [SPM] observations at fixed field stations, the mean relative error (MRE of the predicted SPM is 17.7%, which is lower than that of the GOCI-derived [SPM] (27.5%. In addition, thanks to the derived high-resolution [SPM] with high spatiotemporal dynamic changes, both natural phenomena (dynamic variation of the maximum turbid zone and human engineering changes leading to the dynamic variability of SPM in the channel are observed.

  5. An Improved Method for Producing High Spatial-Resolution NDVI Time Series Datasets with Multi-Temporal MODIS NDVI Data and Landsat TM/ETM+ Images

    OpenAIRE

    Yuhan Rao; Xiaolin Zhu; Jin Chen; Jianmin Wang

    2015-01-01

    Due to technical limitations, it is impossible to have high resolution in both spatial and temporal dimensions for current NDVI datasets. Therefore, several methods are developed to produce high resolution (spatial and temporal) NDVI time-series datasets, which face some limitations including high computation loads and unreasonable assumptions. In this study, an unmixing-based method, NDVI Linear Mixing Growth Model (NDVI-LMGM), is proposed to achieve the goal of accurately and efficiently bl...

  6. Proof of principle of a high-spatial-resolution, resonant-response {gamma}-ray detector for Gamma Resonance Absorption in {sup 14}N

    Energy Technology Data Exchange (ETDEWEB)

    Brandis, M; Goldberg, M B; Vartsky, D; Mardor, I; Levi, S; Mor, I; Bar, D [Nuclear Physics Division, Soreq NRC, Yavne 81800 (Israel); Friedman, E [Racah Institute of Physics, Hebrew University of Jerusalem, Jerusalem 91904 (Israel); Kreslo, I [Laboratory for High Energy Physics (LHEP), University of Bern, Bern 3012 (Switzerland); Dangendorf, V, E-mail: michal_brandis@yahoo.com [Physikalisch-Technisch-Bundesanstalt (PTB), Braunschweig 38116 (Germany)

    2011-02-01

    The development of a mm-spatial-resolution, resonant-response detector based on a micrometric glass capillary array filled with liquid scintillator is described. This detector was developed for Gamma Resonance Absorption (GRA) in {sup 14}N. GRA is an automatic-decision radiographic screening technique that combines high radiation penetration (the probe is a 9.17 MeV {gamma}-ray) with very good sensitivity and specificity to nitrogenous explosives. Detailed simulation of the detector response to electrons and protons generated by the 9.17 MeV {gamma}-rays was followed by a proof-of-principle experiment, using a mixed {gamma}-ray and neutron source. Towards this, a prototype capillary detector was assembled, including the associated filling and readout systems. Simulations and experimental results indeed show that proton tracks are distinguishable from electron tracks at relevant energies, based on a criterion that combines track length and light intensity per unit length.

  7. Land use change detection and prediction using high spatial resolution Google Earth imagery and GIS techniques: a study on El-Beheira Governorate, Egypt

    Science.gov (United States)

    Abdelaty, Emad Fawzy Saad

    2016-08-01

    Land Use change has become a vital component in current strategies for monitoring environmental changes and managing natural resources. Urban growth has brought serious losses of cultivated land, vegetation land and water bodies. In this study, we have taken North of Damanhour city as a case study to determine the land use change that took place in a period of time about of 6 years from 2008 to 2014 for investigation of changes after the revolution of January 25. The approach used in this study is the integration between Remote Sensing and GIS whereas the Google Earth was the source of data, while ArcGIS for further analysis of the digitized data. Google Earth has positioned itself at the forefront of a spatial information wave through providing free access to high-resolution imagery with simple, user friendly interface. The change detection is performed using historical imagery as a new tool in Google Earth program. Change detection rate shows that built-up area has been increased by 107.22 % between 2008 and 2014 whereas the urban area was 62.07 ha in 2008 and became 128.62 ha in 2014, on the other side the cultivated area has been decreased by 11.15 % between 2008 and 2014 whereas it changed from 596.74 ha in 2008 to 530.19 in 2014. The forecast function was used to predict land use changes between 2014 and 2032 based on 2008-2014 trends. Between 2014 and 2032, it was predicted that agricultural lands would decrease by 37.15% and built-up would increase by 40.70%.

  8. Synoptic estimates of diffuse groundwater seepage to a spring-fed karst river at high spatial resolution using an automated radon measurement technique

    Science.gov (United States)

    Khadka, Mitra B.; Martin, Jonathan B.; Kurz, Marie J.

    2017-01-01

    Groundwater (GW) seepage can provide a major source of water, solutes, and contaminants to rivers, but identifying magnitudes, directions and locations of seepage is complicated by its diffuse and heterogeneous distributions. However, such information is necessary to develop programs and policies for protecting ecosystems and managing water resources. Here, we assess GW seepage to the Ichetucknee River, a spring-fed, low gradient, gaining stream in north-central Florida, through automated longitudinal surveys of radon (222Rn) activities at three different flow conditions. A 222Rn mass balance model, which integrates groundwater and spring water end member 222Rn activities and longitudinal 222Rn distributions in river water, shows that diffuse groundwater seepage represents about 16% of the total river baseflow, consistent with previous results obtained from ion (Ca2+, Cl-, SRP and Fe) mass balances and dye tracer methods. During high river stage, the contribution from seepage increases to 18-23% of the river flow. The spatial distribution of GW seepage is more variable in the upper 2.2-km reach of the river than the lower 2.8-km reach, regardless of river flow conditions. The upper reach has a narrower flood plain than the lower reach, which limits evapotranspiration and increases hydraulic gradients toward the river following storm events. Seepage in the lower reach is also limited by hydrologic damming by the receiving river, which inundates the floodplain during high flow conditions, and reduces the hydraulic head gradient. These results demonstrate the variable nature of seepage to a gaining river in both time and space and indicate that multiple synoptic analyses of GW seepage are required to assess seepage rates, determine time-averaged solute fluxes, and develop optimal management policies for riverine ecosystems.

  9. Long-term vegetation activity trends in the Iberian Peninsula and The Balearic Islands using high spatial resolution NOAA-AVHRR data (1981 - 2015).

    Science.gov (United States)

    Martin-Hernandez, Natalia; Vicente-Serrano, Sergio; Azorin-Molina, Cesar; Begueria-Portugues, Santiago; Reig-Gracia, Fergus; Zabalza-Martínez, Javier

    2017-04-01

    We have analysed trends in the Normalized Difference Vegetation Index (NDVI) in the Iberian Peninsula and The Balearic Islands over the period 1981 - 2015 using a new high resolution data set from the entire available NOAA - AVHRR images (IBERIAN NDVI dataset). After a complete processing including geocoding, calibration, cloud removal, topographic correction and temporal filtering, we obtained bi-weekly time series. To assess the accuracy of the new IBERIAN NDVI time-series, we have compared temporal variability and trends of NDVI series with those results reported by GIMMS 3g and MODIS (MOD13A3) NDVI datasets. In general, the IBERIAN NDVI showed high reliability with these two products but showing higher spatial resolution than the GIMMS dataset and covering two more decades than the MODIS dataset. Using the IBERIAN NDVI dataset, we analysed NDVI trends by means of the non-parametric Mann-Kendall test and Theil-Sen slope estimator. In average, vegetation trends in the study area show an increase over the last decades. However, there are local spatial differences: the main increase has been recorded in humid regions of the north of the Iberian Peninsula. The statistical techniques allow finding abrupt and gradual changes in different land cover types during the analysed period. These changes are related with human activity due to land transformations (from dry to irrigated land), land abandonment and forest recovery.

  10. Simulation, optimization and testing of a novel high spatial resolution X-ray imager based on Zinc Oxide nanowires in Anodic Aluminium Oxide membrane using Geant4

    Science.gov (United States)

    Esfandi, F.; Saramad, S.

    2015-07-01

    In this work, a new generation of scintillator based X-ray imagers based on ZnO nanowires in Anodized Aluminum Oxide (AAO) nanoporous template is characterized. The optical response of ordered ZnO nanowire arrays in porous AAO template under low energy X-ray illumination is simulated by the Geant4 Monte Carlo code and compared with experimental results. The results show that for 10 keV X-ray photons, by considering the light guiding properties of zinc oxide inside the AAO template and suitable selection of detector thickness and pore diameter, the spatial resolution less than one micrometer and the detector detection efficiency of 66% are accessible. This novel nano scintillator detector can have many advantages for medical applications in the future.

  11. The application of FORMOSAT-2 high-temporal- and high-spatial resolution imagery for monitoring open straw burning and carbon emission detection

    Directory of Open Access Journals (Sweden)

    C.-C. Liu

    2013-03-01

    Full Text Available Rice is produced in more than 95 countries worldwide and is a staple food for over half of the world's population. Rice is also a major food crop of Taiwan. There are numerous rice crops planted on the western plains of Taiwan, and, after the harvest season, the left-over straw is often burned on-site. The air pollutants from the burning emissions include CO2, CO, CH4 and other suspended particles, most of these being the greenhouse gases which cause global climate change. In this study FORMOSAT-2 satellite images and ground-truth data from 2008 and 2009 are used to conduct supervised classification and calculate the extent of the straw burning areas. It was found that 10% of the paddies in the study area were burned after harvest during this 2-yr period. On this pro rata basis, we calculated the overall carbon emissions from the burning of the straw. The findings showed that these few farmers produced up to 34 000 tons of carbon emissions in 2008, and 40 000 tons in 2009. The study results indicate that remotely sensed images can be used to efficiently evaluate the important characteristics for carbon emission detection. It also provides quantitative results that are relevant to tracking sources of transport pollution, postharvest burning, and Asian dust in Taiwan.

  12. Analyses at High Spatial Resolution of Organic Molecules in Extraterrestrial Samples: Two-Step Laser Mass Spectrometry: Search for Polycyclic Aromatic Hydrocarbons in Antarctic Meteorite and Micrometeorite Samples

    Science.gov (United States)

    Zare, Richard N.

    1998-01-01

    Perhaps the best way to summarize the past three-year grant period is to cite the publications and present a brief synopsis of each: 1. "Indigenous Polycyclic Aromatic Hydrocarbon Molecules in Circumstellar Graphite Grains." Bulk C-12/C-13 isotope ratios observed in some graphite grains extracted from primitive meteorites point strongly to a circumstellar origin. By applying our technique of microprobe two-step laser desorption laser ionization mass spectrometry ((mu)L(sup 2)MS) to individual circumstellar graphite grains we have measured the C-12/C-13 isotope ratio of various polycyclic aromatic hydrocarbons (PAHS) found in these grains. 2. "Deuterium Enrichments in Cluster IDPS," Large enrichments in the D/H isotope ratios in IDPs likely arise from the preservation of presolar molecules. 3. "Evidence for thermalization of surface-disorder molecules at heating rates of 10(exp 8) K/s". A careful study of the ((mu)L(sup 2)MS) of aniline-d(sub 7) from a single-crystal surface (0001) of sapphire (al2O3) shows that all measured properties are consistent with a thermal mechanism for desorption. 4. "Search for past life on Mars; possible relic biogenic activity in Martian meteorite ALH 84001. The authors examined the Martian meteorite ALH 84001 and found several lines of evidence compatible with existence of past primitive (single-cell) life on early Mars. 5. "Microprobe two-step laser mass spectrometry as an analytical tool for meteorite samples". THis paper presents a comprehensive review of (mu)L(sup 2)MS and how this technique can be applied to meteoritic samples. 6. "Indigenous polycyclic aromatic hydrocarbons in circumstellar graphite grains from primitive meteorites". The C-12/C-13 isotope ratios were measured for PAHs in a total of 89 spherical graphite grains. 7. "Observation of indigenous polycyclic aromatic hydrocarbons in "Giant" carbonaceous antarctic micrometeorites." The (mu)L(sup 2)MS method was used to establish the nature and distribution of PAHs in fragments of fifteen (approx. 200 microns) carbonaceous antarctic micrometeorites (AMMs). 8. "Evidence for the extraterrestrial origin of polycyclic aromatic hydrocarbons in the Martian meteorite ALH 84001" We have undertaken additional contamination studies of ALH 84001.

  13. High Spatial Resolution Thermal Infrared Remote Sensing Data for Analysis of the Atlanta, Georgia, Urban Heat Island Effect and Its Impacts on the Environment

    Science.gov (United States)

    Quattrochi, Dale A.

    2007-01-01

    The twenty-first century is the first "urban century" according to the United Nations Development Program. The focus of cities reflects awareness of the growing percentage of the world's population that lives in urban areas. In environmental terms, cities are the original producers of many of the global problems related to waste disposal, air and water pollution, and associated environmental and ecological challenges. Expansion of cities, both in population and areal extent, is a relentless process. In 2000, approximately 3 billion people representing about 40% of the global population, resided in urban areas. Urban population will continue to rise substantially over the next several decades according to UN estimates, and most of this growth will Occur in developing countries. The UN estimates that by 2025, 60% of the world's population will live in urban areas. As a consequence, the number of"megacities" (those cities with populations of 10 million inhabitants or more) will increase by 100 by 2025. Thus, there is a critical need to understand urban areas and what their impacts are on environmental, ecological and hydrologic resources, as well as on the local, regional, and even global climate. One of the more egregious side effects of urbanization is the increase in surface and air temperatures that lead to deterioration in air quality. In the United States, under the more stringent air quality guidelines established by the U.S. Environmental Protection Agency in 1997, nearly 300 counties in 34 states will not meet these new air quality standards for ground level ozone. Mitigation of the urban heat island (UHI) effect is actively being evaluated as a possible way to reduce ground ozone levels in cities and assist states in improving air quality. Foremost in the analysis of how the UHI affects air quality and other environmental factors is the use of remote sensing technology and data to characterize urban land covers in sufficient detail to quantifiably measure the impact of increased urban heating on air quality. The urban landscape impacts surface thermal energy exchanges that determine development of the UHI. This paper will illustrate how we are using high spatial remote sensing data collected over the Atlanta, Georgia metropolitan area in conjunction with other geographic information, to perform a detailed urban land cover classification and to determine the contribution of these land covers to the urban heat island effect. Also, the spatial arrangement of the land covers and the impact on urban heating from these selected patterns of development are evaluated. Additionally, this paper will show how these data are being used as inputs to improve air quality modeling for Atlanta, including potential benefits from UHI mitigation.

  14. Developing a bright 17 keV x-ray source for probing high-energy-density states of matter at high spatial resolution

    Energy Technology Data Exchange (ETDEWEB)

    Huntington, C. M.; Park, H.-S.; Maddox, B. R.; Barrios, M. A.; Benedetti, R.; Braun, D. G.; Landen, O. L.; Wehrenberg, C. E.; Remington, B. A. [Lawrence Livermore National Laboratory, Livermore, California, 94551 (United States); Hohenberger, M.; Regan, S. P. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States)

    2015-04-15

    A set of experiments were performed on the National Ignition Facility (NIF) to develop and optimize a bright, 17 keV x-ray backlighter probe using laser-irradiated Nb foils. High-resolution one-dimensional imaging was achieved using a 15 μm wide slit in a Ta substrate to aperture the Nb He{sub α} x-rays onto an open-aperture, time integrated camera. To optimize the x-ray source for imaging applications, the effect of laser pulse shape and spatial profile on the target was investigated. Two laser pulse shapes were used—a “prepulse” shape that included a 3 ns, low-intensity laser foot preceding the high-energy 2 ns square main laser drive, and a pulse without the laser foot. The laser spatial profile was varied by the use of continuous phase plates (CPPs) on a pair of shots compared to beams at best focus, without CPPs. A comprehensive set of common diagnostics allowed for a direct comparison of imaging resolution, total x-ray conversion efficiency, and x-ray spectrum between shots. The use of CPPs was seen to reduce the high-energy tail of the x-ray spectrum, whereas the laser pulse shape had little effect on the high-energy tail. The measured imaging resolution was comparably high for all combinations of laser parameters, but a higher x-ray flux was achieved without phase plates. This increased flux was the result of smaller laser spot sizes, which allowed us to arrange the laser focal spots from multiple beams and produce an x-ray source which was more localized behind the slit aperture. Our experiments are a first demonstration of point-projection geometry imaging at NIF at the energies (>10 keV) necessary for imaging denser, higher-Z targets than have previously been investigated.

  15. Revealing Water Stress by the Thermal Power Industry in China Based on a High Spatial Resolution Water Withdrawal and Consumption Inventory.

    Science.gov (United States)

    Zhang, Chao; Zhong, Lijin; Fu, Xiaotian; Wang, Jiao; Wu, Zhixuan

    2016-02-16

    This study reveals the spatial distribution of water withdrawal and consumption by thermal power generation and the associated water stress at catchment level in China based on a high-resolution geodatabase of electric generating units and power plants. We identified three groups of regions where the baseline water stress exerted by thermal power generation is comparatively significant: (1) the Hai River Basin/East Yellow River Basin in the north; (2) some arid catchments in Xinjiang Autonomous Region in the northwest; and (3) the coastal city clusters in the Yangtze River Delta, Pearly River Delta, and Zhejiang Province. Groundwater stress is also detected singularly in a few aquifers mainly in the Hai River Basin and the lower reaches of the Yellow River Basin. As China accelerates its pace of coal mining and coal-fired power generation in the arid northwest regions, the energy/water priorities in catchments under high water stress are noteworthy. We conclude that promotion of advanced water-efficient technologies in the energy industry and more systematic analysis of the water stress of thermal power capacity expansion in water scarce regions in inland China are needed. More comprehensive and transparent data monitoring and reporting are essential to facilitate such water stress assessment.

  16. Time‐of‐flight secondary ion mass spectrometry imaging of biological samples with delayed extraction for high mass and high spatial resolutions

    Science.gov (United States)

    Vanbellingen, Quentin P.; Elie, Nicolas; Eller, Michael J.; Della‐Negra, Serge; Touboul, David

    2015-01-01

    Rationale In Time‐of‐Flight Secondary Ion Mass Spectrometry (TOF‐SIMS), pulsed and focused primary ion beams enable mass spectrometry imaging, a method which is particularly useful to map various small molecules such as lipids at the surface of biological samples. When using TOF‐SIMS instruments, the focusing modes of the primary ion beam delivered by liquid metal ion guns can provide either a mass resolution of several thousand or a sub‐µm lateral resolution, but the combination of both is generally not possible. Methods With a TOF‐SIMS setup, a delayed extraction applied to secondary ions has been studied extensively on rat cerebellum sections in order to compensate for the effect of long primary ion bunches. Results The use of a delayed extraction has been proven to be an efficient solution leading to unique features, i.e. a mass resolution up to 10000 at m/z 385.4 combined with a lateral resolution of about 400 nm. Simulations of ion trajectories confirm the experimental determination of optimal delayed extraction and allow understanding of the behavior of ions as a function of their mass‐to‐charge ratio. Conclusions Although the use of a delayed extraction has been well known for many years and is very popular in MALDI, it is much less used in TOF‐SIMS. Its full characterization now enables secondary ion images to be recorded in a single run with a submicron spatial resolution and with a mass resolution of several thousand. This improvement is very useful when analyzing lipids on tissue sections, or rare, precious, or very small size samples. © 2015 The Authors. Rapid Communications in Mass Spectrometry published by John Wiley & Sons Ltd. PMID:26395603

  17. High spatial resolution detectors and particle lifetime measurements at Lep; Detecteurs a haute resolution spatiale et mesures de la duree de vie des particules a Lep

    Energy Technology Data Exchange (ETDEWEB)

    Coyle, P. [Universite de la Mediterranee, Centre de Physique des Particules de Marseille, 13 - Marseille (France); Schneider, O. [Lausanne Univ., Inst. de Physique des Hautes Energies (Switzerland)

    2002-11-01

    The design and performance of the LEP silicon vertex detectors are described. Their application to the measurement of the tau-lepton and b-hadron lifetimes is discussed and the current status of these measurements is reviewed. (authors)

  18. LiDAR The Generation of Automatic Mapping for Buildings, Using High Spatial Resolution Digital Vertical Aerial Photography and LiDAR Point Clouds

    Directory of Open Access Journals (Sweden)

    William Barragán Zaque

    2015-06-01

    Full Text Available The aim of this paper is to generate photogrammetrie products and to automatically map buildings in the area of interest in vector format. The research was conducted Bogotá using high resolution digital vertical aerial photographs and point clouds obtained using LIDAR technology. Image segmentation was also used, alongside radiometric and geometric digital processes. The process took into account aspects including building height, segmentation algorithms, and spectral band combination. The results had an effectiveness of 97.2 % validated through ground-truthing.

  19. Development and operation of a Pr_{2}Fe_{14}B based cryogenic permanent magnet undulator for a high spatial resolution x-ray beam line

    Directory of Open Access Journals (Sweden)

    C. Benabderrahmane

    2017-03-01

    Full Text Available Short period, high field undulators are used to produce hard x-rays on synchrotron radiation based storage ring facilities of intermediate energy and enable short wavelength free electron laser. Cryogenic permanent magnet undulators take benefit from improved magnetic properties of RE_{2}Fe_{14}B (Rare Earth based magnets at low temperatures for achieving short period, high magnetic field and high coercivity. Using Pr_{2}Fe_{14}B instead of Nd_{2}Fe_{14}B, which is generally employed for undulators, avoids the limitation caused by the spin reorientation transition phenomenon, and simplifies the cooling system by allowing the working temperature of the undulator to be directly at the liquid nitrogen one (77 K. We describe here the development of a full scale (2 m, 18 mm period Pr_{2}Fe_{14}B cryogenic permanent magnet undulator (U18. The design, construction and optimization, as well as magnetic measurements and shimming at low temperature are presented. The commissioning and operation of the undulator with the electron beam and spectrum measurement using the Nanoscopmium beamline at SOLEIL are also reported.

  20. High Spatial Resolution Size Resolved Aerosol Observations on both the Neighborhood Scale and from a UAV in the Lowermost Boundary Layer

    Science.gov (United States)

    Lary, D. J.; Harrison, W. A.; Nathan, B.; Moore, A. G.

    2015-12-01

    Airborne particulates play a central role in both the earth's radiation balance and as a trigger for a wide range of health impacts. Air quality monitors are placed in networks across many cities globally. Typically these provide at best a few recording locations per city. However, large spatial variability occurs on the neighborhood scale. This study sets out to comprehensively characterize a full size distribution from 0.25 - 32 μm of airborne particulates on a fine spatial scale (meters) using two phases. In phase one the data is gathered at ground level on a near daily basis over the month of May, 2014 in a 100 km2 area encompassing parts of Richardson, and Garland, TX. Variograms were used to determine an appropriate spatial scale for future measurements to provide PM characterization on a neighborhood scale. The results showed the spatial scales varied, depending on the synoptic weather pattern, from 0.8 km to 5.2 km, with a typical spatial scale of 1.6 km. Phase two used a remote-controlled aerial vehicle to look at the horizontal, vertical, and temporal variability of airborne particulates within the first 150 m of the atmosphere. Four flights where conducted on December 4, 2014 between 12:00 pm and 5:00 pm local time. The first three flights flew a pattern of increasing altitude up to 140 m. The fourth flight was conducted at a near constant altitude of 60 m. The mean PM2.5 concentration for the three flights with varying altitude was 36.3 μgm^-3, with the highest concentration occurring below 10 m altitude. The overall vertical variation was very small with a standard deviation of only 3.6 μgm^-3. PM2.5 concentration did not change much throughout the day with mean concentrations variation of only 2.1 μgm^-3. The fourth flight, flown at a near constant altitude, corroborated the spatial scales found in phase one.

  1. A high-spatial-resolution three-dimensional detector array for 30-200 keV X-rays based on structured scintillators

    DEFF Research Database (Denmark)

    Olsen, Ulrik Lund; Schmidt, Søren; Poulsen, Henning Friis

    2008-01-01

    A three-dimensional X-ray detector for imaging 30-200 keV photons is described. It comprises a set of semi-transparent structured scintillators, where each scintillator is a regular array of waveguides in silicon, and with pores filled with CsI. The performance of the detector is described...... theoretically and explored in detail through simulations. Based on available hardware, a spatial resolution of 1 mm is obtainable. The resolution of a single screen is shown to be determined only by the pitch, at least up to 100 keV. In comparison with conventional homogeneous screens, an improvement...... in efficiency by a factor of 5-15 is obtainable. The cross-talk between screens in the three-dimensional detector is shown to be negligible. The three-dimensional concept enables ray-tracing and super-resolution algorithms to be applied....

  2. High spatial resolution radiation budget for Europe: derived from satellite data, validation of a regional model; Raeumlich hochaufgeloeste Strahlungsbilanz ueber Europa: Ableitung aus Satellitendaten, Validation eines regionalen Modells

    Energy Technology Data Exchange (ETDEWEB)

    Hollmann, R. [GKSS-Forschungszentrum Geesthacht GmbH (Germany). Inst. fuer Atmosphaerenphysik

    2000-07-01

    Since forty years instruments onboard satellites have been demonstrated their usefulness for many applications in the field of meteorology and oceanography. Several experiments, like ERBE, are dedicated to establish a climatology of the global Earth radiation budget at the top of the atmosphere. Now the focus has been changed to the regional scale, e.g. GEWEX with its regional sub-experiments like BALTEX. To obtain a regional radiation budget for Europe in the first part of the work the well calibrated measurements from ScaRaB (scanner for radiation budget) are used to derive a narrow-to-broadband conversion, which is applicable to the AVHRR (advanced very high resolution radiometer). It is shown, that the accuracy of the method is in the order of that from SCaRaB itself. In the second part of the work, results of REMO have been compared with measurements of ScaRaB and AVHRR for March 1994. The model reproduces the measurements overall well, but it is overestimating the cold areas and underestimating the warm areas in the longwave spectral domain. Similarly it is overestimating the dark areas and underestimating the bright areas in the solar spectral domain. (orig.)

  3. Confocal Raman microscopy as a tool to describe different mineral and organic phases at high spatial resolution within marine biogenic carbonates: case study on Nerita undata (Gastropoda, Neritopsina)

    Science.gov (United States)

    Nehrke, G.; Nouet, J.

    2011-06-01

    Marine biogenic carbonates formed by invertebrates (e.g. corals and mollusk shells) represent complex composites of one or more mineral phases and organic molecules. This complexity ranges from the macroscopic structures observed with the naked eye down to sub micrometric structures only revealed by micro analytical techniques. Understanding to what extent and how organisms can control the formation of these structures requires that the mineral and organic phases can be identified and their spatial distribution related. Here we demonstrate the capability of confocal Raman microscopy applied to cross sections of a shell of Nerita undata to describe the distribution of calcite and aragonite including their crystallographic orientation with high lateral resolution (∼300 nm). Moreover, spatial distribution of functional groups of organic compounds can be simultaneously acquired, allowing to specifically relate them to the observed microstructures. The data presented in this case study highlights the possible new contributions of this method to the description of modalities of Nerita undata shell formation, and what could be expected of its application to other marine biogenic carbonates. Localization of areas of interest would also allow further investigations using more localized methods, such as TEM that would provide complementary information on the relation between organic molecules and crystallographic lattice.

  4. The Design and Implementation in $0.13\\mu m$ CMOS of an Algorithm Permitting Spectroscopic Imaging with High Spatial Resolution for Hybrid Pixel Detectors

    OpenAIRE

    Ballabriga, Rafael; Campbell, Michael; Vilasís-Cardona, Xavier

    2009-01-01

    Advances in pixel detector technology are opening up new possibilities in many fields of science. Modern High Energy Physics (HEP) experiments use pixel detectors in tracking systems where excellent spatial resolution, precise timing and high signal-to-noise ratio are required for accurate and clean track reconstruction. Many groups are working worldwide to adapt the hybrid pixel technology to other fields such as medical X-ray radiography, protein structure analysis or neutron imaging. The M...

  5. The chemical composition and mineralogy of meteorites measured with very high spatial resolution by a laser mass spectrometer for in situ planetary research

    Science.gov (United States)

    Brigitte Neuland, Maike; Mezger, Klaus; Tulej, Marek; Frey, Samira; Riedo, Andreas; Wurz, Peter; Wiesendanger, Reto

    2017-04-01

    The knowledge of the chemical composition of moons, comets, asteroids or other planetary bodies is of particular importance for the investigation of the origin and evolution of the Solar System. High resolution in situ studies on planetary surfaces can yield important information on surface heterogeneity, basic grain mineralogy and chemical composition of surface and subsurface. In turn, these data are the basis for our understanding of the physical and chemical processes which led to the formation and alteration of planetary material [1]. We investigated samples of Allende and Sayh al Uhaymir with a highly miniaturised laser mass spectrometer (LMS), which has been designed and built for in situ space research [2,3]. Both meteorite samples were investigated with a spatial resolution of about 10μm in lateral direction. The high sensitivity and high dynamic range of the LMS allow for quantitative measurements of the abundances of the rock-forming and minor and trace elements with high accuracy [4]. From the data, the modal mineralogy of micrometre-sized chondrules can be inferred [5], conclusions about the condensation sequence of the material are possible and the sensitivity for radiogenic elements allows for dating analyses of the investigated material. We measured the composition of various chondrules in Allende, offering valuable clues about the condensation sequence of the different components of the meteorite. We explicitly investigated the chemical composition and heterogeneity of the Allende matrix with an accuracy that cannot be reached by the mechanical analysis methods that were and are widely used in meteoritic research. We demonstrate the capabilities for dating analyses with the LMS. By applying the U-Th-dating method, the age of the SaU169 sample could be determined. Our analyses show that the LMS would be a suitable instrument for high-quality quantitative chemical composition measurements on the surface of a celestial body like a planet, moon or asteroid. [1] Wurz, P., Whitby, J., Managadze, G. , "Laser Mass Spectrometry in Planetary Science", AIP Conf.Proc. CP1144(2009): 70-75. [2] Rohner, U., Whitby, J.A. and Wurz, P. "A miniature laser ablation time-of-flight mass spectrometer for in situ planetary exploration", Measurement Science and Technology 14 (2003): 2159-2164. [3] Riedo, A., Bieler, A., Neuland, M., Tulej, M. and Wurz, P., "Performance evaluation of a miniature laser ablation time-of-flight mass spectrometer designed for in situ investigations in planetary space research", Journal of Mass Spectrometry 48 (2013): 1 -15 [4] Neuland, M.B., Grimaudo, V., Mezger, K., Moreno-García, P., Riedo, A., Tulej, M. and Wurz, P., "Quantitative measurement of the chemical composition of geological standards with a miniature laser ablation/ionisation mass spectrometer designed for in situ application in space research", Meas. Sci. Technol. 27(2016), article ID:035904, 1 - 13. [5] Tulej, M., Neubeck, A., Ivarsson, M., Riedo, A., Neuland, M.B., Meyer, S. and Wurz, P., "Chemical composition of micrometer-sized filaments in an aragonite host by a miniature laser ablation/ionization mass spectrometer", Astrobiol., 15 (2015): 669 - 682.

  6. MALIBU: A High Spatial Resolution Multi-Angle Imaging Unmanned Airborne System to Validate Satellite-derived BRDF/Albedo Products

    Science.gov (United States)

    Wang, Z.; Roman, M. O.; Pahlevan, N.; Stachura, M.; McCorkel, J.; Bland, G.; Schaaf, C.

    2016-12-01

    Albedo is a key climate forcing variable that governs the absorption of incoming solar radiation and its ultimate transfer to the atmosphere. Albedo contributes significant uncertainties in the simulation of climate changes; and as such, it is defined by the Global Climate Observing System (GCOS) as a terrestrial essential climate variable (ECV) required by global and regional climate and biogeochemical models. NASA's Goddard Space Flight Center's Multi AngLe Imaging Bidirectional Reflectance Distribution Function small-UAS (MALIBU) is part of a series of pathfinder missions to develop enhanced multi-angular remote sensing techniques using small Unmanned Aircraft Systems (sUAS). The MALIBU instrument package includes two multispectral imagers oriented at two different viewing geometries (i.e., port and starboard sides) capture vegetation optical properties and structural characteristics. This is achieved by analyzing the surface reflectance anisotropy signal (i.e., BRDF shape) obtained from the combination of surface reflectance from different view-illumination angles and spectral channels. Satellite measures of surface albedo from MODIS, VIIRS, and Landsat have been evaluated by comparison with spatially representative albedometer data from sparsely distributed flux towers at fixed heights. However, the mismatch between the footprint of ground measurements and the satellite footprint challenges efforts at validation, especially for heterogeneous landscapes. The BRDF (Bidirectional Reflectance Distribution Function) models of surface anisotropy have only been evaluated with airborne BRDF data over a very few locations. The MALIBU platform that acquires extremely high resolution sub-meter measures of surface anisotropy and surface albedo, can thus serve as an important source of reference data to enable global land product validation efforts, and resolve the errors and uncertainties in the various existing products generated by NASA and its national and international partners.

  7. Integrated change detection and temporal trajectory analysis of coastal wetlands using high spatial resolution Korean Multi-Purpose Satellite series imagery

    Science.gov (United States)

    Nguyen, Hoang Hai; Tran, Hien; Sunwoo, Wooyeon; Yi, Jong-hyuk; Kim, Dongkyun; Choi, Minha

    2017-04-01

    A series of multispectral high-resolution Korean Multi-Purpose Satellite (KOMPSAT) images was used to detect the geographical changes in four different tidal flats between the Yellow Sea and the west coast of South Korea. The method of unsupervised classification was used to generate a series of land use/land cover (LULC) maps from satellite images, which were then used as input for temporal trajectory analysis to detect the temporal change of coastal wetlands and its association with natural and anthropogenic activities. The accurately classified LULC maps of KOMPSAT images, with overall accuracy ranging from 83.34% to 95.43%, indicate that these multispectral high-resolution satellite data are highly applicable to the generation of high-quality thematic maps for extracting wetlands. The result of the trajectory analysis showed that, while the variation of the tidal flats in the Gyeonggi and Jeollabuk provinces was well correlated with the regular tidal regimes, the reductive trajectory of the wetland areas belonging to the Saemangeum province was caused by a high degree of human-induced activities including large reclamation and urbanization. The conservation of the Jeungdo Wetland Protected Area in the Jeollanam province revealed that effective social and environmental policies could help in protecting coastal wetlands from degradation.

  8. Weight-loss medicines

    Science.gov (United States)

    Prescription weight loss drugs; Diabetes - weight loss drugs; Obesity - weight loss drugs; Overweight - weight loss drugs ... are not approved by the FDA to treat weight-loss. So you should not take them if you do not have diabetes.

  9. MR imaging of iliofemoral peripheral vascular calcifications using proton density-weighted, in-phase three-dimensional stack-of-stars gradient echo.

    Science.gov (United States)

    Ferreira Botelho, Marcos P; Koktzoglou, Ioannis; Collins, Jeremy D; Giri, Shivraman; Carr, James C; Gupta, NavYash; Edelman, Robert R

    2017-06-01

    The presence of vascular calcifications helps to determine percutaneous access for interventional vascular procedures and has prognostic value for future cardiovascular events. Unlike CT, standard MRI techniques are insensitive to vascular calcifications. In this prospective study, we tested a proton density-weighted, in-phase (PDIP) three-dimensional (3D) stack-of-stars gradient-echo pulse sequence with approximately 1 mm 3 isotropic spatial resolution at 1.5 Tesla (T) and 3T to detect iliofemoral peripheral vascular calcifications and correlated MR-determined lesion volumes with CT angiography (CTA). The study was approved by the Institutional Review Board. The prototype PDIP stack-of-stars pulse sequence was applied in 12 patients with iliofemoral peripheral vascular calcifications who had undergone CTA. Vascular calcifications were well visualized in all subjects, excluding segments near prostheses or stents. The location, size, and shape of the calcifications were similar to CTA. Quantitative analysis showed excellent correlation (r 2  = 0.84; P stars outperformed cartesian 3D gradient-echo and point-wise encoding time reduction with radial acquisition (PETRA). In this pilot study, a PDIP 3D stack-of-stars gradient-echo pulse sequence with high spatial resolution provided excellent image quality and accurately depicted the location and volume of iliofemoral vascular calcifications. Magn Reson Med 77:2146-2152, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

  10. In vivo assessment of iron content of the cerebral cortex in healthy aging using 7-Tesla T2*-weighted phase imaging.

    Science.gov (United States)

    Buijs, Mathijs; Doan, Nhat Trung; van Rooden, Sanneke; Versluis, Maarten J; van Lew, Baldur; Milles, Julien; van der Grond, Jeroen; van Buchem, Mark A

    2017-05-01

    Accumulation of brain iron has been suggested as a biomarker of neurodegeneration. Increased iron has been seen in the cerebral cortex in postmortem studies of neurodegenerative diseases and healthy aging. Until recently, the diminutive thickness of the cortex and its relatively low iron content have hampered in vivo study of cortical iron accumulation. Using phase images of a T2*-weighted sequence at ultrahigh field strength (7 Tesla), we examined the iron content of 22 cortical regions in 70 healthy subjects aged 22-80 years. The cortex was automatically segmented and parcellated, and phase shift was analyzed using an in-house developed method. We found a significant increase in phase shift with age in 20 of 22 cortical regions, concurrent with current understanding of cortical iron accumulation. Our findings suggest that increased cortical iron content can be assessed in healthy aging in vivo. The high spatial resolution and sensitivity to iron of our method make it a potentially useful tool for studying cortical iron accumulation in healthy aging and neurodegenerative diseases. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. Semi-Physical Estimates of National-Scale PM10 Concentrations in China Using a Satellite-Based Geographically Weighted Regression Model

    Directory of Open Access Journals (Sweden)

    Tianhao Zhang

    2016-06-01

    Full Text Available The estimation of ambient particulate matter with diameter less than 10 µm (PM10 at high spatial resolution is currently quite limited in China. In order to make the distribution of PM10 more accessible to relevant departments and scientific research institutions, a semi-physical geographically weighted regression (GWR model was established in this study to estimate nationwide mass concentrations of PM10 using easily available MODIS AOD and NCEP Reanalysis meteorological parameters. The results demonstrated that applying physics-based corrections could remarkably improve the quality of the dataset for better model performance with the adjusted R2 between PM10 and AOD increasing from 0.08 to 0.43, and the fitted results explained approximately 81% of the variability in the corresponding PM10 mass concentrations. Annual average PM10 concentrations estimated by the semi-physical GWR model indicated that many residential regions suffer from severe particle pollution. Moreover, the deviation in estimation, which primarily results from the frequent changes in elevation, the spatially heterogeneous distribution of monitoring sites, and the limitations of AOD retrieval algorithm, was acceptable. Therefore, the semi-physical GWR model provides us with an effective and efficient method to estimate PM10 at large scale. The results could offer reasonable estimations of health impacts and provide guidance on emission control strategies in China.

  12. A robust multi-shot scan strategy for high-resolution diffusion weighted MRI enabled by multiplexed sensitivity-encoding (MUSE).

    Science.gov (United States)

    Chen, Nan-Kuei; Guidon, Arnaud; Chang, Hing-Chiu; Song, Allen W

    2013-05-15

    Diffusion weighted magnetic resonance imaging (DWI) data have been mostly acquired with single-shot echo-planar imaging (EPI) to minimize motion induced artifacts. The spatial resolution, however, is inherently limited in single-shot EPI, even when the parallel imaging (usually at an acceleration factor of 2) is incorporated. Multi-shot acquisition strategies could potentially achieve higher spatial resolution and fidelity, but they are generally susceptible to motion-induced phase errors among excitations that are exacerbated by diffusion sensitizing gradients, rendering the reconstructed images unusable. It has been shown that shot-to-shot phase variations may be corrected using navigator echoes, but at the cost of imaging throughput. To address these challenges, a novel and robust multi-shot DWI technique, termed multiplexed sensitivity-encoding (MUSE), is developed here to reliably and inherently correct nonlinear shot-to-shot phase variations without the use of navigator echoes. The performance of the MUSE technique is confirmed experimentally in healthy adult volunteers on 3Tesla MRI systems. This newly developed technique should prove highly valuable for mapping brain structures and connectivities at high spatial resolution for neuroscience studies. Copyright © 2013 Elsevier Inc. All rights reserved.

  13. Overweight, Obesity, and Weight Loss

    Science.gov (United States)

    ... Back to section menu Healthy Weight Weight and obesity Underweight Weight, fertility, and pregnancy Weight loss and ... section Home Healthy Weight Healthy Weight Weight and obesity Underweight Weight, fertility, and pregnancy Weight loss and ...

  14. In vivo T2* weighted MRI visualizes cardiac lesions in murine models of acute and chronic viral myocarditis.

    Directory of Open Access Journals (Sweden)

    Xavier Helluy

    Full Text Available Acute and chronic forms of myocarditis are mainly induced by virus infections. As a consequence of myocardial damage and inflammation dilated cardiomyopathy and chronic heart failure may develop. The gold standard for the diagnosis of myocarditis is endomyocardial biopsies which are required to determine the etiopathogenesis of cardiac inflammatory processes. However, new non-invasive MRI techniques hold great potential in visualizing cardiac non-ischemic inflammatory lesions at high spatial resolution, which could improve the investigation of the pathophysiology of viral myocarditis.Here we present the discovery of a novel endogenous T2* MRI contrast of myocardial lesions in murine models of acute and chronic CVB3 myocarditis. The evaluation of infected hearts ex vivo and in vivo by 3D T2w and T2*w MRI allowed direct localization of virus-induced myocardial lesions without any MRI tracer or contrast agent. T2*w weighted MRI is able to detect both small cardiac lesions of acute myocarditis and larger necrotic areas at later stages of chronic myocarditis, which was confirmed by spatial correlation of MRI hypointensity in myocardium with myocardial lesions histologically. Additional in vivo and ex vivo MRI analysis proved that the contrast mechanism was due to a strong paramagnetic tissue alteration in the vicinity of myocardial lesions, effectively pointing towards iron deposits as the primary contributor of contrast. The evaluation of the biological origin of the MR contrast by specific histological staining and transmission electron microscopy revealed that impaired iron metabolism primarily in mitochondria caused iron deposits within necrotic myocytes, which induces strong magnetic susceptibility in myocardial lesions and results in strong T2* contrast.This T2*w MRI technique provides a fast and sensitive diagnostic tool to determine the patterns and the severity of acute and chronic enteroviral myocarditis and the precise localization of

  15. Weight Gain during Pregnancy

    Science.gov (United States)

    ... Global Map Premature Birth Report Cards Careers Archives Pregnancy Before or between pregnancies Nutrition, weight & fitness Prenatal ... fitness > Weight gain during pregnancy Weight gain during pregnancy E-mail to a friend Please fill in ...

  16. Fake weighted projective spaces

    OpenAIRE

    Buczynska, Weronika

    2008-01-01

    We define fake weighted projective spaces as a generalisation of weighted projective spaces. We introduce the notions of fundamental group in codimension 1 and of universal covering in codimension 1. We prove that for every fake weighted projective space its universal cover in codimension 1 is a weighted projective space.

  17. Weight Loss Surgery

    Science.gov (United States)

    Weight loss surgery helps people with extreme obesity to lose weight. It may be an option if you cannot lose weight through diet and exercise or have serious health problems caused by obesity. There are different types of weight loss surgery. They often limit the amount of food ...

  18. Proven Weight Loss Methods

    Science.gov (United States)

    Fact Sheet Proven Weight Loss Methods What can weight loss do for you? Losing weight can improve your health in a number of ways. ... you feel better. There are proven ways to lose weight. You can find what works for you. Research ...

  19. Effect of clothing weight on body weight.

    Science.gov (United States)

    Whigham, L D; Schoeller, D A; Johnson, L K; Atkinson, R L

    2013-01-01

    In clinical settings, it is common to measure weight of clothed patients and estimate a correction for the weight of clothing, but we can find no papers in the medical literature regarding the variability in clothing weight of adults with weather, season and gender. Fifty adults (35 women) were weighed four times during a 12-month period with and without clothing. Clothing weights were determined and regressed against minimum, maximum and average daily outdoor temperature. The average clothing weight (±s.d.) throughout the year was significantly greater in men than in women (1.2±0.3 vs 0.8±0.3 kg, Pclothing weights across the year were 0.9±0.2 and 1.5±0.4 kg for men, and 0.5±0.2 and 1.1±0.4 kg for women, respectively. The within-person s.d. in clothing weight was 0.3 kg for both men and women. Over the 55 °C range in the lowest to the highest outdoor temperatures, the regressions predicted a maximal change in clothing weight of only 0.4 kg in women and 0.6 kg in men. The clothing weight of men is significantly greater than that of women, but there is little variability throughout the year. Therefore, a clothing adjustment of approximately 0.8 kg for women and 1.2 kg for men is appropriate regardless of outdoor temperature.

  20. Weight Loss & Acute Porphyria

    Science.gov (United States)

    ... APF You are here Home Diet and Nutrition Weight loss & acute Porphyria Being overweight is a particular problem ... of carbohydrate and energy in an effort to lose weight can worsen these diseases. Severe acute attacks have ...

  1. Yogurt and weight management.

    Science.gov (United States)

    Jacques, Paul F; Wang, Huifen

    2014-05-01

    A large body of observational studies and randomized controlled trials (RCTs) has examined the role of dairy products in weight loss and maintenance of healthy weight. Yogurt is a dairy product that is generally very similar to milk, but it also has some unique properties that may enhance its possible role in weight maintenance. This review summarizes the human RCT and prospective observational evidence on the relation of yogurt consumption to the management and maintenance of body weight and composition. The RCT evidence is limited to 2 small, short-term, energy-restricted trials. They both showed greater weight losses with yogurt interventions, but the difference between the yogurt intervention and the control diet was only significant in one of these trials. There are 5 prospective observational studies that have examined the association between yogurt and weight gain. The results of these studies are equivocal. Two of these studies reported that individuals with higher yogurt consumption gained less weight over time. One of these same studies also considered changes in waist circumference (WC) and showed that higher yogurt consumption was associated with smaller increases in WC. A third study was inconclusive because of low statistical power. A fourth study observed no association between changes in yogurt intake and weight gain, but the results suggested that those with the largest increases in yogurt intake during the study also had the highest increase in WC. The final study examined weight and WC change separately by sex and baseline weight status and showed benefits for both weight and WC changes for higher yogurt consumption in overweight men, but it also found that higher yogurt consumption in normal-weight women was associated with a greater increase in weight over follow-up. Potential underlying mechanisms for the action of yogurt on weight are briefly discussed.

  2. Weight maintenance: what's missing?

    Science.gov (United States)

    Hill, James O; Thompson, Helen; Wyatt, Holly

    2005-05-01

    Obesity has reached epidemic proportions in the United States, but there are few proven strategies for either preventing further weight gain or producing permanent weight loss. Our first priority should be to prevent the gradual weight gain experienced by much of the population. Although this will require less behavior change than producing and maintaining weight loss, helping Americans make and sustain the behavior changes needed to prevent gradual weight increases will be challenging. Because approximately 65% of Americans are already overweight or obese, we must also develop effective strategies to help achieve and maintain an amount of weight loss that improves their health and quality of life. Our real challenge is not in helping people lose weight but in helping them keep it off. Many programs have been shown to produce weight loss but few, if any, have been successful in maintenance of weight loss. Our challenge is in understanding how to help people keep off the weight they can lose in several ways.

  3. Healthy weight game!: Lose weight together

    NARCIS (Netherlands)

    Lentelink, S.J.; Spil, Antonius A.M.; Broens, T.; Broens, T.H.F.; Hermens, Hermanus J.; Jones, Valerie M.

    2013-01-01

    Overweight and obesity pose a serious and increasing problem worldwide. Current treatment methods can result in weight loss in the short term but often fail in the longer term. Increasing motivation and thereby improving adherence can be a key factor in achieving the needed behavioral change. One

  4. Predictors of weight maintenance

    NARCIS (Netherlands)

    Pasman, W.J.; Saris, W.H.M.; Westerterp-Plantenga, M.S.

    1999-01-01

    Objective: To obtain predictors of weight maintenance after a weight-loss intervention. Research Methods and Procedures: An overall analysis of data from two-long intervention studies [n = 67 women; age: 37.9±1.0 years; body weight (BW): 87.0±1.2 kg; body mass index: 32.1±0.5 kg·m-2; % body fat:

  5. Robustness of weighted networks

    Science.gov (United States)

    Bellingeri, Michele; Cassi, Davide

    2018-01-01

    Complex network response to node loss is a central question in different fields of network science because node failure can cause the fragmentation of the network, thus compromising the system functioning. Previous studies considered binary networks where the intensity (weight) of the links is not accounted for, i.e. a link is either present or absent. However, in real-world networks the weights of connections, and thus their importance for network functioning, can be widely different. Here, we analyzed the response of real-world and model networks to node loss accounting for link intensity and the weighted structure of the network. We used both classic binary node properties and network functioning measure, introduced a weighted rank for node importance (node strength), and used a measure for network functioning that accounts for the weight of the links (weighted efficiency). We find that: (i) the efficiency of the attack strategies changed using binary or weighted network functioning measures, both for real-world or model networks; (ii) in some cases, removing nodes according to weighted rank produced the highest damage when functioning was measured by the weighted efficiency; (iii) adopting weighted measure for the network damage changed the efficacy of the attack strategy with respect the binary analyses. Our results show that if the weighted structure of complex networks is not taken into account, this may produce misleading models to forecast the system response to node failure, i.e. consider binary links may not unveil the real damage induced in the system. Last, once weighted measures are introduced, in order to discover the best attack strategy, it is important to analyze the network response to node loss using nodes rank accounting the intensity of the links to the node.

  6. Vaccination against Weight Gain

    National Research Council Canada - National Science Library

    Eric P. Zorrilla; Shinichi Iwasaki; Jason A. Moss; Jason Chang; Jonathan Otsuji; Koki Inoue; Michael M. Meijler; Kim D. Janda

    2006-01-01

    .... Here we show that active vaccination of mature rats with ghrelin immunoconjugates decreases feed efficiency, relative adiposity, and body weight gain in relation to the immune response elicited...

  7. Body Weight Perception and Weight Control Practices among Teenagers

    OpenAIRE

    Bhurtun, Darshini Devi; Jeewon, Rajesh

    2013-01-01

    Background. Weight-loss behaviours are highly prevalent among adolescents, and body weight perception motivates weight control practices. However, little is known about the association of body weight perception, and weight control practices among teenagers in Mauritius. The aim of this study is to investigate the relationships between actual body weight, body weight perception, and weight control practices among teenagers. Methods. A questionnaire-based survey was used to collect data on anth...

  8. Preventing Weight Gain

    Science.gov (United States)

    ... healthy weight, visit Physical Activity for Healthy Weight . Self-monitoring You may also find it helpful to weigh yourself on a regular basis. If you see a few pounds creeping on, take the time to examine your lifestyle. With these strategies, you make it more likely that you’ll ...

  9. Body Weight - Multiple Languages

    Science.gov (United States)

    ... Supplements Videos & Tools You Are Here: Home → Multiple Languages → All Health Topics → Body Weight URL of this page: https://medlineplus.gov/ ... V W XYZ List of All Topics All Body Weight - Multiple Languages To use the sharing features on this page, ...

  10. Weight and psychiatry

    African Journals Online (AJOL)

    Adele

    weight loss in morbidly obeses patients undergoing bariatric surgery. Obes Surg. 2002; 12: 835-40. 11. World Health Organisation. The ICD-10 Classification of Mental and. Behavioural Disorders. Clinical descriptions and diagnostic guidelines. The clinical relevance of weight in psychiatry varies. It may be:- I. an associated ...

  11. birth-weight infants

    African Journals Online (AJOL)

    hours of life was more strongly associated with death than four traditional risk factors (birth weight, short gestation, male sex and the diagnosis of respiratory distress syndrome). Furthermore, mean pH in the first 12 hours was as strongly associated with death as was birth weight. Previous research in our neonatal population ...

  12. Weight discrimination and bullying.

    Science.gov (United States)

    Puhl, Rebecca M; King, Kelly M

    2013-04-01

    Despite significant attention to the medical impacts of obesity, often ignored are the negative outcomes that obese children and adults experience as a result of stigma, bias, and discrimination. Obese individuals are frequently stigmatized because of their weight in many domains of daily life. Research spanning several decades has documented consistent weight bias and stigmatization in employment, health care, schools, the media, and interpersonal relationships. For overweight and obese youth, weight stigmatization translates into pervasive victimization, teasing, and bullying. Multiple adverse outcomes are associated with exposure to weight stigmatization, including depression, anxiety, low self-esteem, body dissatisfaction, suicidal ideation, poor academic performance, lower physical activity, maladaptive eating behaviors, and avoidance of health care. This review summarizes the nature and extent of weight stigmatization against overweight and obese individuals, as well as the resulting consequences that these experiences create for social, psychological, and physical health for children and adults who are targeted. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Weighted Automata Algorithms

    Science.gov (United States)

    Mohri, Mehryar

    Weighted automata and transducers are widely used in modern applications in bioinformatics and text, speech, and image processing. This chapter describes several fundamental weighted automata and shortest-distance algorithms including composition, determinization, minimization, and synchronization, as well as single-source and all-pairs shortest distance algorithms over general semirings. It presents the pseudocode of these algorithms, gives an analysis of their running time complexity, and illustrates their use in some simple cases. Many other complex weighted automata and transducer algorithms used in practice can be obtained by combining these core algorithms.

  14. Adolescent Weight Status

    DEFF Research Database (Denmark)

    Hjort Kjelldgaard, Heidi; Holstein, Bjørn Evald; Due, Pernille

    2017-01-01

    -aged Children study 2010. The study population (n = 4,922) included students in the fifth, seventh, and ninth grade from a representative sample of Danish schools. Multinomial logistic regression analyses were used to study the associations between weight status and social relations, supported by a conceptual...... framework for the study of social relations. RESULTS: Among girls, overweight/obese weight status was associated with spending less time with friends after school compared to normal-weight status (0 days/week: odds ratio: 6.25, 95% confidence interval: 2.18-17.95, 1 day/week: 2.81, 1.02-7.77, 2 days/week: 3...

  15. Thyroid and Weight

    Science.gov (United States)

    ... thyroid hormones are elevated, such as in the toxic phase of thyroiditis (see Thyroiditis brochure ) and if ... discontinued. HYPOTHYROIDISM AND THYROID HORMONE WHAT IS THE RELATIONSHIP BETWEEN HYPOTHYROIDISM AND WEIGHT GAIN? Since the BMR ...

  16. Weight Loss Surgery

    Science.gov (United States)

    ... medical problems . These problems include diabetes , heart disease, sleep apnea , and joint trouble . Lots of very overweight people turn their weight around by sticking to a doctor-approved diet ...

  17. Assessing Your Weight

    Science.gov (United States)

    ... meters and weight in kilograms. However, the BMI formula has been adapted for height measured in inches ... file Microsoft PowerPoint file Microsoft Word file Microsoft Excel file Audio/Video file Apple Quicktime file RealPlayer ...

  18. Weight loss and alcohol

    Science.gov (United States)

    ... want to keep an eye on how drinking affects your eating habits. Calories and Portions Count So, how much can you drink if you are trying to lose weight? Health experts recommend that anyone who drinks does so ...

  19. Lorcaserin for weight management

    OpenAIRE

    Taylor, James R; Dietrich, Eric; Powell, Jason

    2013-01-01

    James R Taylor, Eric Dietrich, Jason PowellUniversity of Florida College of Pharmacy, Department of Pharmacotherapy and Translational Research, Gainesville, FL, USAAbstract: Type 2 diabetes and obesity commonly occur together. Obesity contributes to insulin resistance, a main cause of type 2 diabetes. Modest weight loss reduces glucose, lipids, blood pressure, need for medications, and cardiovascular risk. A number of approaches can be used to achieve weight loss, including lifestyle modifica...

  20. Weight loss update.

    Science.gov (United States)

    1996-11-01

    Unwanted weight loss in people with HIV can be caused by one or more factors simultaneously. A two-pronged approach that addresses the factors causing weight loss and malnutrition, and maintaining or gaining weight is critical. Many opportunistic infections (OIs) can cause diarrhea, but both the drugs used to treat diarrhea and the infections themselves can contribute to weight loss. Lactose intolerance is a common cause of diarrhea in people living with HIV. Because some of the drugs used to treat HIV and OIs are packaged with lactose, it may be necessary to replace the enzymes needed to break down lactose. Appetite loss may also contribute to wasting, and the lack of nutrients from a lost appetite can tax the body and further aggravate the problem. Appetite stimulants, vitamin supplements, or weight gain products that promote the building of protein are possible treatment options. Lean body mass production may require the use of anabolic (protein building) steroids or testosterone replacement therapy. Another wasting intervention option involves recombinant human growth hormone (rHGH), however, unsubstantiated safety concerns have arisen on the use of rHGH, and may require increased monitoring. Finally, counteracting weight loss may require adjusting the elevated levels of an immune system chemical called tumor necrosis factor (TNF) with thalidomide. Because of thalidomide's association with birth defects, sexually active heterosexual women should be advised to use multiple contraceptive mechanisms.

  1. Relationship between egg weight, hatch weight and subsequent ...

    African Journals Online (AJOL)

    Three hundred (300) Fulani Ecotype (FE) chicken eggs collected from free ranged Fulani Ecotype chicken were used to study the effect of egg weight on hatch weight and subsequent body weight. Eggs were grouped into two according to their weight (small and medium) and incubated. Body weight of the chicks was ...

  2. Weight Loss Nutritional Supplements

    Science.gov (United States)

    Eckerson, Joan M.

    Obesity has reached what may be considered epidemic proportions in the United States, not only for adults but for children. Because of the medical implications and health care costs associated with obesity, as well as the negative social and psychological impacts, many individuals turn to nonprescription nutritional weight loss supplements hoping for a quick fix, and the weight loss industry has responded by offering a variety of products that generates billions of dollars each year in sales. Most nutritional weight loss supplements are purported to work by increasing energy expenditure, modulating carbohydrate or fat metabolism, increasing satiety, inducing diuresis, or blocking fat absorption. To review the literally hundreds of nutritional weight loss supplements available on the market today is well beyond the scope of this chapter. Therefore, several of the most commonly used supplements were selected for critical review, and practical recommendations are provided based on the findings of well controlled, randomized clinical trials that examined their efficacy. In most cases, the nutritional supplements reviewed either elicited no meaningful effect or resulted in changes in body weight and composition that are similar to what occurs through a restricted diet and exercise program. Although there is some evidence to suggest that herbal forms of ephedrine, such as ma huang, combined with caffeine or caffeine and aspirin (i.e., ECA stack) is effective for inducing moderate weight loss in overweight adults, because of the recent ban on ephedra manufacturers must now use ephedra-free ingredients, such as bitter orange, which do not appear to be as effective. The dietary fiber, glucomannan, also appears to hold some promise as a possible treatment for weight loss, but other related forms of dietary fiber, including guar gum and psyllium, are ineffective.

  3. Lorcaserin for weight management.

    Science.gov (United States)

    Taylor, James R; Dietrich, Eric; Powell, Jason

    2013-01-01

    Type 2 diabetes and obesity commonly occur together. Obesity contributes to insulin resistance, a main cause of type 2 diabetes. Modest weight loss reduces glucose, lipids, blood pressure, need for medications, and cardiovascular risk. A number of approaches can be used to achieve weight loss, including lifestyle modification, surgery, and medication. Lorcaserin, a novel antiobesity agent, affects central serotonin subtype 2A receptors, resulting in decreased food intake and increased satiety. It has been studied in obese patients with type 2 diabetes and results in an approximately 5.5 kg weight loss, on average, when used for one year. Headache, back pain, nasopharyngitis, and nausea were the most common adverse effects noted with lorcaserin. Hypoglycemia was more common in the lorcaserin groups in the clinical trials, but none of the episodes were categorized as severe. Based on the results of these studies, lorcaserin was approved at a dose of 10 mg twice daily in patients with a body mass index ≥30 kg/m(2) or ≥27 kg/m(2) with at least one weight-related comorbidity, such as hypertension, type 2 diabetes mellitus, or dyslipidemia, in addition to a reduced calorie diet and increased physical activity. Lorcaserin is effective for weight loss in obese patients with and without type 2 diabetes, although its specific role in the management of obesity is unclear at this time. This paper reviews the clinical trials of lorcaserin, its use from the patient perspective, and its potential role in the treatment of obesity.

  4. An ultra-clean technique for accurately analysing Pb isotopes and heavy metals at high spatial resolution in ice cores with sub-pg g{sup -1} Pb concentrations

    Energy Technology Data Exchange (ETDEWEB)

    Burn, Laurie J. [Department of Imaging and Applied Physics, Curtin University of Technology, GPO Box U1987, Perth 6845, Western Australia (Australia); Rosman, Kevin J.R. [Department of Imaging and Applied Physics, Curtin University of Technology, GPO Box U1987, Perth 6845, Western Australia (Australia)], E-mail: K.Rosman@curtin.edu.au; Candelone, Jean-Pierre [Department of Imaging and Applied Physics, Curtin University of Technology, GPO Box U1987, Perth 6845, Western Australia (Australia); Vallelonga, Paul [Department of Imaging and Applied Physics, Curtin University of Technology, GPO Box U1987, Perth 6845, Western Australia (Australia); Istituto per la Dinamica dei Processi Ambientali (IDPA-CNR), Dorsoduro 2137, 30123 Venice (Italy); Burton, Graeme R. [Department of Imaging and Applied Physics, Curtin University of Technology, GPO Box U1987, Perth 6845, Western Australia (Australia); Smith, Andrew M. [Australian Nuclear Science and Technology Organisation (ANSTO), PMB 1, Menai, NSW 2234 (Australia); Morgan, Vin I. [Australian Antarctic Division and Antarctic Climate and Ecosystems CRC, Private Bag 80, Hobart, Tasmania 7001 (Australia); Barbante, Carlo [Istituto per la Dinamica dei Processi Ambientali (IDPA-CNR), Dorsoduro 2137, 30123 Venice (Italy); Hong, Sungmin [Korea Polar Research Institute, Songdo Techno Park, 7-50, Songdo-dong, Yeonsu-gu, Incheon 406-840 (Korea, Republic of); Boutron, Claude F. [Laboratoire de Glaciologie et Geophysique de l' Environnement du CNRS, 54, rue Moliere, B.P. 96, 3840.2 St Martin d' Heres Cedex (France)

    2009-02-23

    Measurements of Pb isotope ratios in ice containing sub-pg g{sup -1} concentrations are easily compromised by contamination, particularly where limited sample is available. Improved techniques are essential if Antarctic ice cores are to be analysed with sufficient spatial resolution to reveal seasonal variations due to climate. This was achieved here by using stainless steel chisels and saws and strict protocols in an ultra-clean cold room to decontaminate and section ice cores. Artificial ice cores, prepared from high purity water were used to develop and refine the procedures and quantify blanks. Ba and In, two other important elements present at pg g{sup -1} and fg g{sup -1} concentrations in Polar ice, were also measured. The final blank amounted to 0.2 {+-} 0.2 pg of Pb with {sup 206}Pb/{sup 207}Pb and {sup 208}Pb/{sup 207}Pb ratios of 1.16 {+-} 0.12 and 2.35 {+-} 0.16, respectively, 1.5 {+-} 0.4 pg of Ba and 0.6 {+-} 2.0 fg of In, most of which probably originates from abrasion of the steel saws by the ice. The procedure was demonstrated on a Holocene Antarctic ice core section and was shown to contribute blanks of only {approx}5%, {approx}14% and {approx}0.8% to monthly resolved samples with respective Pb, Ba and In concentrations of 0.12 pg g{sup -1}, 0.3 pg g{sup -1} and 2.3 fg g{sup -1}. Uncertainties in the Pb isotopic ratio measurements were degraded by only {approx}0.2%.

  5. Flat coil-based tunnel diode oscillator enabling to detect the real shape of the superconductive transition curve and capable of imaging the properties of HTSC films with high spatial resolution

    Energy Technology Data Exchange (ETDEWEB)

    Gevorgyan, Samvel E-mail: gevs_sam@web.amsamvel@ipr.sci.am; Shirinyan, Hovsep; Manukyan, Artashes; Sharoyan, Eduard; Takeo, Masakatsu; Polyanskii, Anatolii; Sarkisyan, Albert; Matsushita, Teruo

    2004-03-11

    Owing to a pick-up coil's flat design, relatively low MHz-range operation frequency, and six orders relative resolution a flat coil-based tunnel diode oscillator has advantages, compared to all other methods. They become crucial in studies with thin high-T{sub c} superconductivity (HTSC) materials (with small signals), especially at the start of the Cooper pairs' formation. Due to this the superconductivity precursor 'paramagnetic' effect was detected recently in YBaCuO films at N/S transition. It precedes Meissner ejection and specifies details of the shape of the transition curve. We discuss the influence of the currents on this effect, and the relationship between the quality of the material and the shape of the effect. A new imaging device has also been created based on this test method (using a focused He-Ne laser beam as a probing signal), capable of imaging the properties of HTSC films with {approx}3 {mu}m spatial resolution. The method is based on detection of the inductance and Q-factor value changes of a single-layer flat coil, placed at the face of the sample. This leads to frequency and/or amplitude changes of the stable oscillator. The test device enabled 2D-mapping of the grain structure of a bridge-shaped YBaCuO film. Basically, the method is capable of imaging 2D-current distribution in thin HTS with sub-{mu}m spatial-resolution, using non-bolometric response. However, the achieved resolution {approx}3 {mu}m of a bolometric nature (in a given device with 3.5 mm-size coil) by no means is limited by the abilities of the method, but mainly, it depends on how narrowly it is possible to focus the probing beam, while the own resolution of a present flat coil-based technique is better than 0.1 {mu}m, and can be improved essentially by reducing the coil size.

  6. Intra-and-Inter Species Biomass Prediction in a Plantation Forest: Testing the Utility of High Spatial Resolution Spaceborne Multispectral RapidEye Sensor and Advanced Machine Learning Algorithms

    Directory of Open Access Journals (Sweden)

    Timothy Dube

    2014-08-01

    Full Text Available The quantification of aboveground biomass using remote sensing is critical for better understanding the role of forests in carbon sequestration and for informed sustainable management. Although remote sensing techniques have been proven useful in assessing forest biomass in general, more is required to investigate their capabilities in predicting intra-and-inter species biomass which are mainly characterised by non-linear relationships. In this study, we tested two machine learning algorithms, Stochastic Gradient Boosting (SGB and Random Forest (RF regression trees to predict intra-and-inter species biomass using high resolution RapidEye reflectance bands as well as the derived vegetation indices in a commercial plantation. The results showed that the SGB algorithm yielded the best performance for intra-and-inter species biomass prediction; using all the predictor variables as well as based on the most important selected variables. For example using the most important variables the algorithm produced an R2 of 0.80 and RMSE of 16.93 t·ha−1 for E. grandis; R2 of 0.79, RMSE of 17.27 t·ha−1 for P. taeda and R2 of 0.61, RMSE of 43.39 t·ha−1 for the combined species data sets. Comparatively, RF yielded plausible results only for E. dunii (R2 of 0.79; RMSE of 7.18 t·ha−1. We demonstrated that although the two statistical methods were able to predict biomass accurately, RF produced weaker results as compared to SGB when applied to combined species dataset. The result underscores the relevance of stochastic models in predicting biomass drawn from different species and genera using the new generation high resolution RapidEye sensor with strategically positioned bands.

  7. Toward an estimation of daily european CO{sub 2} fluxes at high spatial resolution by inversion of atmospheric transport; Vers une estimation des flux de CO{sub 2} journaliers europeens a haute resolution par inversion du transport atmospherique

    Energy Technology Data Exchange (ETDEWEB)

    Carouge, C

    2006-04-15

    Since the end of the 1980's, measurements of atmospheric carbon dioxide have been used to estimate global and regional fluxes of CO{sub 2}. This is possible because CO{sub 2} concentration variation is directly linked to flux variation by atmospheric transport. We can find the spatial and temporal distribution of fluxes from concentration measurements by 'inverting' the atmospheric transport. Until recently, most CO{sub 2} inversions have used monthly mean CO{sub 2} atmospheric concentration measurements to infer monthly fluxes. Considering the sparseness of the global CO{sub 2} measurement network, fluxes were a priori aggregated on sub-continental regions and distributed on a fixed spatial pattern within these regions. Only one flux coefficient per month for each region was optimized. With this strong constraint, estimated fluxes can be biased by non-perfect distribution of fluxes within each region (aggregation error). Therefore, flux estimation at model resolution is being developed where the hard constraint of a fixed distribution within a region is replaced by a soft constraint of covariances between flux uncertainties. The use of continuous observations from an increasing number of measurement sites offers a new challenge for inverse modelers. We investigate the use of daily averaged observations to infer daily CO{sub 2} fluxes at model resolution over Europe. We have developed a global synthesis Bayesian inversion to invert daily fluxes at model resolution (50 x 50 km over Europe) from daily averaged CO{sub 2} concentrations. We have obtained estimated fluxes for the year 2001 over Europe using the 10 European continuous sites from the AEROCARB network. The global atmospheric model LMDZt is used with a nested grid over Europe. It is necessary to add a priori spatial and temporal correlations between flux errors to constrain the Bayesian inversion. We present the impact on estimated fluxes of three different spatial correlations based on distance between pixels, climate and vegetation distribution over Europe. To study the potential of this method, we used synthetic data generated from forward simulations of LMDZt (driven by flux fields generated from the biosphere model ORCHIDEE). We have found that the current network is not dense enough to constrain fluxes at model resolution. However, fluxes that are aggregated spatially over a region of 850 x 850 km in the Western Europe and temporally over 8-10 days compare very well with the ORCHIDEE fluxes. Preliminary inversion results using real data indicate that synoptic variations of estimated fluxes are in phase with the variations of the ORCHIDEE biosphere model flux and the variations observed in atmospheric concentrations. However, the quality of the flux estimates are highly dependant on transport model errors and in particular, on the quality of modelling small scale transport. Moreover, fossil fuel emissions are prescribed in this inverse model and the quality of their distribution is shown to be crucial. Data selection also has a large impact on estimated fluxes. The use of the daytime only data to calculate daily averaged concentrations greatly improves the estimated fluxes by reducing bias inferred from model transport errors. (author)

  8. Concordant ages for the Lava Creek Tuff from high-spatial-resolution U-Pb dating of zircon rim faces and single-crystal sanidine 40Ar/39Ar dating

    Science.gov (United States)

    Matthews, N. E.; Vazquez, J. A.; Calvert, A. T.

    2013-12-01

    The last great explosive supereruption from the Yellowstone Plateau formed present-day Yellowstone caldera and ejected the >1000 km3 of rhyolite that composes the Lava Creek Tuff (LCT). The LCT eruption blanketed much of the western United States in ash, and consequently is a key chronostratigraphic marker bed for delimiting Quaternary uplift rates, the age of middle Pleistocene glacial and pluvial deposits, and tephra correlation in North America. Previous 40Ar/39Ar dating of the two mineralogically distinct LCT members (A & B) yield ages ranging from ca. 600 ka (Gansecki et al., 1998) to ca. 640 ka (Lanphere et al., 2002). To resolve the timing of eruption and crystallization timescale for the LCT magma, we dated both LCT members using a dual-method approach as follows: (1) ion microprobe (SHRIMP-RG) U-Pb dating and trace-element characterization of the final few micrometers of zircon crystallization by analysis of unpolished rims on indium-mounted crystals, and dating of the onset of zircon crystallization by traditional analysis of sectioned crystal interiors, and (2) laser-fusion 40Ar/39Ar dating of single sanidine crystals from bulk LCT ignimbrite and pumice. The unpolished rims of zircon from LCT members A & B yield indistinguishable ages, with a mean age of 621.8 × 2.5 ka (1σ) after correction for initial 230Th disequilibrium as constrained by ion-probe analyses of LCT melt inclusions. Single sanidine crystals from LCT-B yield a mean age of 624.9 × 2.6 ka (FCT=28.17 Ma) that is indistinguishable from the zircon rim ages for both members. These results indicate that LCT members A & B erupted over a geologically brief interval, which is supported by the direct and gradational contact of their equivalent fallout in distal lacustrine deposits and a lack of field evidence for a significant time-break between the LCT A & B in proximal deposits (Christiansen, 2001), but contrasts with older Yellowstone ignimbrite (e.g., Huckleberry Ridge) that may have erupted as multiple pulses over tens of kyr (Ellis et al., 2012). Both LCT members contain zircon whose interiors yield U-Pb ages that are mostly ca. 40 kyr older than their rims, suggesting a short timescale for assembly of the LCT magma chamber relative to some other voluminous bodies of silicic magma (e.g., Fish Canyon). Trace-element concentrations in zircon from Members A and B appear diagnostic, with the former containing higher U and REE concentrations. Our concordant results from U-Pb and 40Ar/39Ar dating indicating a ca. 625 ka age for the LCT eruption are supported by the stratigraphic position of LCT-B tephra at or near the top of Great Basin pluvial lake bed sequences associated with Marine Isotope Stage 16, whose termination is astronomically dated at 621 ka. Christiansen, 2001, USGS Prof. Pap. 729-G; Ellis et al., 2012, Quat Geochron 9: 31-41; Gansecki et al., 1998, Geology 26(4): 343-346; Lanphere et al., 2002, GSA Bull. 114(5): 559-568.

  9. High-frequency high-spatial resolution US in transplanted kidney in pediatric patients; Studio ecografico con sonda con alta frequenza ed elevata risoluzione spaziale nella valutazione del rene trapiantato nell'eta' pediatrica

    Energy Technology Data Exchange (ETDEWEB)

    Amodio, F.; Rossi, E.; Carbone, M.; Brunese, L.; Tamasi, S.; Vallone, G. [Neaples Univ. Federico 2, Neaples (Italy). Dipt. di Scienze Biomorfologiche e Funzionali; Mansueto, G.; Somma, P. [Neaples Univ. Federico 2, Neaples (Italy). Sezione di Anatomia Patologica e Citopatologica

    2000-02-01

    In this paper it is presented the role power Doppler US with a high-frequency and high-resolution of interlobular arterioles in patients with normally functioning renal transplants or with chronic rejection. 15 patients (mean age 15 years; range 10-18 years) were examined with a General Electric 500 MD unit using 7.5 and 13 MHz linear transducers. In all the patients serum creatinine and diuresis were evaluated; 4 patients underwent US-guided biopsy that resulted in the diagnosis of chronic rejection. Normally functioning renal transplants were found in 11 patients and chronic rejection was seen in 4. In normally functioning renal transplants, interlobular vessels could be depicted as cortical blush with the 7.5 MHz transducer; in the same patients power Doppler US with the 13 MHz transducer permitted a correct evaluation of interlobular vessels that were arranged in series like a palisade. In chronic rejection power Doppler US with the 13 MHz transducer better depicted cortical vascularity and showed irregular, narrow arteries. Power Doppler US with a 13 MHz transducer is particularly useful in children after renal transplants due to their reduced tissutal thickness. The lateral resolution of 13 MHz transducers (<0.3 mm) allows to separate interlobular vessels from each other and the high frequency of the probe can depict interlobular vessels in the peripheral cortex. The optimal visualization of cortical vascularity with a 13 MHz transducer allows early detection of chronic rejection. [Italian] Si valuta la sensibilita' del power Doppler con sonda con alta frequenza ed elevata risoluzione spaziale (13 MHz) nella visualizzazione della vascolarizzazione corticale del rene trapiantato normo-funzionante e nel rigetto cronico nell'eta' pediatrica. Quindici pazienti (10 maschi/5 femmine) con eta' media di 15 anni (intervallo 10-18 anni) sono stati esaminati con ecografo MD 500 mediante sonda da 7,5 e 13 MHz con color e power Doppler. Tutti i pazienti sono stati monitorizzati con valutazione della creatininemia, azotemia e diuresi nelle 24 ore. Nei 4 casi patologici e' stata eseguita biopsia renale eco-guidata. Dei 15 pazienti 11 avevano normale funzionalita' renale e 4 presentavano rigetto cronico. Nei pazienti con normale funzionalita' renale lo studio con power Doppler con sonda da 7,5 MHz ha permesso in tutti i casi la visualizzazione dei vasi interlobulari rappresentati dalla somma di una serie di segnali con lieve intensita' (effetto di sommazione); l'utilizzazione della sonda da 13MHz, in virtu' dell'elevata risoluzione laterale (<0,3 mm), ha consentito di suddividere il segnale vascolare nelle singole componenti (vasi interlobulari) e ha permesso ottimale mappattura della vascolarizzazione corticale. Nei pazienti con rigetto cronico l'esame con power Doppler consonda da 7,5 MHz ha mostrato scarsa vascolarizzazione corticale mentre con l'utilizzazione della sonda da 13 MHz e' stata rilevata in tutti i casi la presenza di vascolarizzazione ridotta e patologica evidenziando i vasi interlobulari tortuosi e con calibro ridotto. Lo studio del rene trapiantato con sonda da 13 MHz appare particolarmente adatto ai pazienti pediatrici per i ridotti spessori tissutali che permettono il passaggio di onde ultrasonore con alta frequenza. L'ottimale visualizzazione della vascolarizzazione corticale puo' permettere il riconoscimento precoce di tutte quelle condizioni (es. rigetto acuto e cronico) nelle quali la riduzione generalizzata della vascolarizzazione corticale si correla con il livelli di creatininemia.

  10. High spatial resolution X-UV Fresnel zone plates imaging; Imagerie a haute resolution spatiale dans le domaine X-UV a l'aide de lentilles a zone de Fresnel

    Energy Technology Data Exchange (ETDEWEB)

    Pichet-Thomasset, M

    1999-07-01

    The goal of this work is to study the capabilities of imaging of Fresnel zone plates in the 1.5. and 2 keV X-ray range for the imaging of laser-produced plasmas. The diagnostic is composed of a Fresnel zone plate with good imaging capabilities and a multilayer mirror to select the spectral emission bandwidth of the plasma we want to study. This diagnostic was evaluated at the Centre d'Etudes de Limeil-Valenton experiments to study spatial resolution with this kind of X-ray source. The images we obtained showed that there is no geometric aberrations over an object field of several millimetre. Fresnen zone plates are often used for monochromatic biological objects imaging in the water window around 400 eV but they offer large prospects for laser produced plasma imaging. (author)

  11. Confocal Raman microscope mapping as a tool to describe different mineral and organic phases at high spatial resolution within marine biogenic carbonates: case study on Nerita undata (Gastropoda, Neritopsina

    Directory of Open Access Journals (Sweden)

    J. Nouet

    2011-12-01

    Full Text Available Marine biogenic carbonates formed by invertebrates (e.g. corals and mollusks represent complex composites of one or more mineral phases and organic molecules. This complexity ranges from the macroscopic structures observed with the naked eye down to sub micrometric structures only revealed by micro analytical techniques. Understanding to what extent and how organisms can control the formation of these structures requires that the mineral and organic phases can be identified and their spatial distribution related. Here we demonstrate the capability of confocal Raman microscopy applied to cross sections of a shell of Nerita undata to describe the distribution of calcite and aragonite including their crystallographic orientation with high lateral resolution (~300 nm. Moreover, spatial distribution of functional groups of organic compounds can be simultaneously acquired, allowing to specifically relate them to the observed microstructures. The data presented in this case study highlights the possible new contributions of this method to the description of modalities of Nerita undata shell formation, and what could be expected of its application to other marine biogenic carbonates. Localization of areas of interest would also allow further investigations using more localized methods, such as TEM that would provide complementary information on the relation between organic molecules and crystal lattice.

  12. Confocal Raman microscope mapping as a tool to describe different mineral and organic phases at high spatial resolution within marine biogenic carbonates: case study on Nerita undata (Gastropoda, Neritopsina)

    Science.gov (United States)

    Nehrke, G.; Nouet, J.

    2011-12-01

    Marine biogenic carbonates formed by invertebrates (e.g. corals and mollusks) represent complex composites of one or more mineral phases and organic molecules. This complexity ranges from the macroscopic structures observed with the naked eye down to sub micrometric structures only revealed by micro analytical techniques. Understanding to what extent and how organisms can control the formation of these structures requires that the mineral and organic phases can be identified and their spatial distribution related. Here we demonstrate the capability of confocal Raman microscopy applied to cross sections of a shell of Nerita undata to describe the distribution of calcite and aragonite including their crystallographic orientation with high lateral resolution (~300 nm). Moreover, spatial distribution of functional groups of organic compounds can be simultaneously acquired, allowing to specifically relate them to the observed microstructures. The data presented in this case study highlights the possible new contributions of this method to the description of modalities of Nerita undata shell formation, and what could be expected of its application to other marine biogenic carbonates. Localization of areas of interest would also allow further investigations using more localized methods, such as TEM that would provide complementary information on the relation between organic molecules and crystal lattice.

  13. MO-FG-204-09: High Spatial Resolution and Artifact-Free CT Bone Imaging at Off-Centered Positions: An Application of Model-Based Iterative Reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Chen, G; Li, K; Gomez-Cardona, D [University of Wisconsin, Madison, WI (United States); Budde, A [University of Wisconsin, Madison, WI (United States); GE Healthcare, Waukesha, WI (United States); Hsieh, J [GE Healthcare, Waukesha, WI (United States)

    2015-06-15

    Purpose: Although the anatomy of interest should be positioned as close as possible to the isocenter of CT scanners, off-centering may be inevitable during certain exams in clinical practice such as lumbar spine and elbow imaging. Off-centering degrades image sharpness, generates streak artifacts, and sometimes creates blooming artifacts due to truncation. The purpose of this work was to investigate whether the use of model-based image reconstruction (MBIR) can alleviate the negative impacts of off-centering to achieve high quality CT bone imaging. Methods: Both an anthropomorphic phantom and an ex vivo swine elbow sample were scanned at centered and off-centered positions using clinical CT bone scan protocols. The magnitude of off-centering was determined from localizer radiographs. Both FBP and MBIR reconstructions were performed. For FBP, both standard and Bone Plus kernels commonly used in bone imaging were used. Objective assessment of image sharpness, noise standard deviation, and noise nonuniformity were performed. Additionally, we retrospectively analyzed human subject data acquired under off-centered conditions as a validation study. Results: In FBP images of the phantom, off-centering by 10 cm led to a 14% increase in noise (p<1e-3) and a 68% increase in noise nonuniformity (p<0.02). A visible drop in bone sharpness was observed. In contrast, no significant difference in the noise magnitude or the noise nonuniformity between the centered and off-centered MBIR images was found. The image sharpness of off-centered MBIR images outperformed that of FBP images reconstructed with the Bone Plus kernel. In images of the swine elbow off-centered by 20 cm, not only was the noise and spatial resolution performance improved by MBIR, truncation artifacts were also elliminated. The human subject study generated similar results, in which the visibility of the off-centered lumbar spine was significantly improved. Conclusion: High quality CT bone imaging at off-centered positions can be achieved using MBIR. This work was partially supported by an NIH grant R01CA169331 and GE Healthcare. K. Li, D. Gomez-Cardona: Nothing to disclose. G.-H. Chen: Research funded, GE Healthcare; Research funded, Siemens AX. A. Budde, J. Hsieh: Employee, GE Healthcare.

  14. Family Weight School treatment

    DEFF Research Database (Denmark)

    Nowicka, Paulina; Höglund, Peter; Pietrobelli, Angelo

    2008-01-01

    OBJECTIVE: The aim was to evaluate the efficacy of a Family Weight School treatment based on family therapy in group meetings with adolescents with a high degree of obesity. METHODS: Seventy-two obese adolescents aged 12-19 years old were referred to a childhood obesity center by pediatricians...... and school nurses and offered a Family Weight School therapy program in group meetings given by a multidisciplinary team. Intervention was compared with an untreated waiting list control group. Body mass index (BMI) and BMI z-scores were calculated before and after intervention. RESULTS: Ninety percent...... group with initial BMI z-score 3.5. CONCLUSIONS: Family Weight School treatment model might be suitable for adolescents with BMI z...

  15. Light weight phosphate cements

    Science.gov (United States)

    Wagh, Arun S.; Natarajan, Ramkumar,; Kahn, David

    2010-03-09

    A sealant having a specific gravity in the range of from about 0.7 to about 1.6 for heavy oil and/or coal bed methane fields is disclosed. The sealant has a binder including an oxide or hydroxide of Al or of Fe and a phosphoric acid solution. The binder may have MgO or an oxide of Fe and/or an acid phosphate. The binder is present from about 20 to about 50% by weight of the sealant with a lightweight additive present in the range of from about 1 to about 10% by weight of said sealant, a filler, and water sufficient to provide chemically bound water present in the range of from about 9 to about 36% by weight of the sealant when set. A porous ceramic is also disclosed.

  16. Dairy cow disability weights.

    Science.gov (United States)

    McConnel, Craig S; McNeil, Ashleigh A; Hadrich, Joleen C; Lombard, Jason E; Garry, Franklyn B; Heller, Jane

    2017-08-01

    Over the past 175 years, data related to human disease and death have progressed to a summary measure of population health, the Disability-Adjusted Life Year (DALY). As dairies have intensified there has been no equivalent measure of the impact of disease on the productive life and well-being of animals. The development of a disease-adjusted metric requires a consistent set of disability weights that reflect the relative severity of important diseases. The objective of this study was to use an international survey of dairy authorities to derive disability weights for primary disease categories recorded on dairies. National and international dairy health and management authorities were contacted through professional organizations, dairy industry publications and conferences, and industry contacts. Estimates of minimum, most likely, and maximum disability weights were derived for 12 common dairy cow diseases. Survey participants were asked to estimate the impact of each disease on overall health and milk production. Diseases were classified from 1 (minimal adverse effects) to 10 (death). The data was modelled using BetaPERT distributions to demonstrate the variation in these dynamic disease processes, and to identify the most likely aggregated disability weights for each disease classification. A single disability weight was assigned to each disease using the average of the combined medians for the minimum, most likely, and maximum severity scores. A total of 96 respondents provided estimates of disability weights. The final disability weight values resulted in the following order from least to most severe: retained placenta, diarrhea, ketosis, metritis, mastitis, milk fever, lame (hoof only), calving trauma, left displaced abomasum, pneumonia, musculoskeletal injury (leg, hip, back), and right displaced abomasum. The peaks of the probability density functions indicated that for certain disease states such as retained placenta there was a relatively narrow range of

  17. Weight-Control Information Network

    Science.gov (United States)

    ... provides the general public and health professionals with evidence-based information and resources on obesity, weight management, physical ... Medical Care for Patients with Obesity Weight Loss & Nutrition Myths Talking with Patients about Weight Loss Find ...

  18. Body Weight Perception and Weight Control Practices among Teenagers

    Science.gov (United States)

    Jeewon, Rajesh

    2013-01-01

    Background. Weight-loss behaviours are highly prevalent among adolescents, and body weight perception motivates weight control practices. However, little is known about the association of body weight perception, and weight control practices among teenagers in Mauritius. The aim of this study is to investigate the relationships between actual body weight, body weight perception, and weight control practices among teenagers. Methods. A questionnaire-based survey was used to collect data on anthropometric measurements, weight perception and weight control practices from a sample of 180 male and female students (90 boys and 90 girls) aged between 13 and 18 years old. Results. Based on BMI, 11.7% of students were overweight. Overall, 43.3% of respondents reported trying to lose weight (61.1% girls and 25.6% boys). Weight-loss behaviours were more prevalent among girls. Among the weight-loss teens, 88.5% students perceived themselves as overweight even though only 19.2% were overweight. Reducing fat intake (84.6%), exercising (80.8%), and increasing intake of fruits and vegetables (73.1%) and decreasing intake of sugar (66.7%) were the most commonly reported methods to lose weight. Conclusion. Body weight perception was poorly associated with actual weight status. Gender difference was observed in body weight perception. PMID:24967256

  19. Bessel Weighted Asymmetries

    Energy Technology Data Exchange (ETDEWEB)

    Avakian, Harut [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Gamberg, Leonard [Pennsylvania State Univ., University Park, PA (United States); Rossi, Patrizia [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Prokudin, Alexei [Pennsylvania State Univ., University Park, PA (United States)

    2016-05-01

    We review the concept of Bessel weighted asymmetries for semi-inclusive deep inelastic scattering and focus on the cross section in Fourier space, conjugate to the outgoing hadron’s transverse momentum, where convolutions of transverse momentum dependent parton distribution functions and fragmentation functions become simple products. Individual asymmetric terms in the cross section can be projected out by means of a generalized set of weights involving Bessel functions. The procedure is applied to studies of the double longitudinal spin asymmetry in semi-inclusive deep inelastic scattering using a new dedicated Monte Carlo generator which includes quark intrinsic transverse momentum within the generalized parton model. We observe a few percent systematic offset of the Bessel-weighted asymmetry obtained from Monte Carlo extraction compared to input model calculations, which is due to the limitations imposed by the energy and momentum conservation at the given energy and hard scale Q2. We find that the Bessel weighting technique provides a powerful and reliable tool to study the Fourier transform of TMDs with controlled systematics due to experimental acceptances and resolutions with different TMD model inputs.

  20. Weight and psychiatry

    African Journals Online (AJOL)

    Adele

    Behavioural Disorders. Clinical descriptions and diagnostic guidelines. The clinical relevance of weight in psychiatry varies. It may be:- I. an associated clinical feature, either primary, as in anorexia nervosa, or secondary as in mood, anxiety or psychotic disorders. II. a related clinical issue, as in bulimia nervosa or an eating ...

  1. Lorcaserin for weight management

    Directory of Open Access Journals (Sweden)

    Taylor JR

    2013-06-01

    Full Text Available James R Taylor, Eric Dietrich, Jason PowellUniversity of Florida College of Pharmacy, Department of Pharmacotherapy and Translational Research, Gainesville, FL, USAAbstract: Type 2 diabetes and obesity commonly occur together. Obesity contributes to insulin resistance, a main cause of type 2 diabetes. Modest weight loss reduces glucose, lipids, blood pressure, need for medications, and cardiovascular risk. A number of approaches can be used to achieve weight loss, including lifestyle modification, surgery, and medication. Lorcaserin, a novel antiobesity agent, affects central serotonin subtype 2A receptors, resulting in decreased food intake and increased satiety. It has been studied in obese patients with type 2 diabetes and results in an approximately 5.5 kg weight loss, on average, when used for one year. Headache, back pain, nasopharyngitis, and nausea were the most common adverse effects noted with lorcaserin. Hypoglycemia was more common in the lorcaserin groups in the clinical trials, but none of the episodes were categorized as severe. Based on the results of these studies, lorcaserin was approved at a dose of 10 mg twice daily in patients with a body mass index ≥30 kg/m2 or ≥27 kg/m2 with at least one weight-related comorbidity, such as hypertension, type 2 diabetes mellitus, or dyslipidemia, in addition to a reduced calorie diet and increased physical activity. Lorcaserin is effective for weight loss in obese patients with and without type 2 diabetes, although its specific role in the management of obesity is unclear at this time. This paper reviews the clinical trials of lorcaserin, its use from the patient perspective, and its potential role in the treatment of obesity.Keywords: lorcaserin, obesity, diabetes

  2. Weight and weight gain during early infancy predict childhood obesity

    DEFF Research Database (Denmark)

    Andersen, Lise Geisler; Holst, Claus; Michaelsen, Kim F.

    2012-01-01

    Infant weight and weight gain are positively associated with later obesity, but whether there is a particular critical time during infancy remains uncertain.......Infant weight and weight gain are positively associated with later obesity, but whether there is a particular critical time during infancy remains uncertain....

  3. Reducing rotor weight

    Energy Technology Data Exchange (ETDEWEB)

    Cheney, M.C. [PS Enterprises, Inc., Glastonbury, CT (United States)

    1997-12-31

    The cost of energy for renewables has gained greater significance in recent years due to the drop in price in some competing energy sources, particularly natural gas. In pursuit of lower manufacturing costs for wind turbine systems, work was conducted to explore an innovative rotor designed to reduce weight and cost over conventional rotor systems. Trade-off studies were conducted to measure the influence of number of blades, stiffness, and manufacturing method on COE. The study showed that increasing number of blades at constant solidity significantly reduced rotor weight and that manufacturing the blades using pultrusion technology produced the lowest cost per pound. Under contracts with the National Renewable Energy Laboratory and the California Energy Commission, a 400 kW (33m diameter) turbine was designed employing this technology. The project included tests of an 80 kW (15.5m diameter) dynamically scaled rotor which demonstrated the viability of the design.

  4. Weighted Feature Distance

    DEFF Research Database (Denmark)

    Ortiz-Arroyo, Daniel; Yazdani, Hossein

    2017-01-01

    The accuracy of machine learning methods for clustering depends on the optimal selection of similarity functions. Conventional distance functions for the vector space might cause an algorithm to being affected by some dominant features that may skew its final results. This paper introduces a flexible...... environment for mining algorithms that uses the most suitable similarity functions to cover the diversity of both vector and feature spaces. The paper describes some well known conventional distance functions and introduces Weighted Feature Distance (WFD) and Prioritized Weighted Feature Distance (PWFD......). These novel functions attempt to balance the impact of the dominant features by covering both feature and vector spaces, additionally to optionally allowing us to increase or decrease the impact of some features. We evaluate and compare the accuracy of our proposed WFD(s) on conventional fuzzy...

  5. Low molecular weight heparins.

    Science.gov (United States)

    Bergqvist, D

    1996-08-01

    Low molecular weight heparins (LMWHs) differ from unfractionated heparin (UFH) in a number of characteristics, which is probably due to differences in molecular weight distribution. From a clinical point of view the better subcutaneous bioavailability and longer biological half-life are important, making it sufficient to inject LMWHs once-daily only. For practical purposes it is also important that LMWHs be used without monitoring. They are effective as prophylaxis against postoperative venous thromboembolism after all types of surgery; in most studies, more effective than UFH. In most studies, this effect can be obtained safely and with less bleeding than with UFH. LMWHs compare favourably with UFH for starting treatment of deep vein thrombosis, as well as an anticoagulant during haemodialysis. Adverse effects such as thrombocytopenia and osteoporosis are more common with UFH than with LMWHs. Studies evaluating whether or not LMWHs can replace UFH in arterial diseases are still few with small sample sizes. Thus further systematic research is needed.

  6. Normal Weight Dyslipidemia

    DEFF Research Database (Denmark)

    Ipsen, David Hojland; Tveden-Nyborg, Pernille; Lykkesfeldt, Jens

    2016-01-01

    Objective: The liver coordinates lipid metabolism and may play a vital role in the development of dyslipidemia, even in the absence of obesity. Normal weight dyslipidemia (NWD) and patients with nonalcoholic fatty liver disease (NAFLD) who do not have obesity constitute a unique subset...... of individuals characterized by dyslipidemia and metabolic deterioration. This review examined the available literature on the role of the liver in dyslipidemia and the metabolic characteristics of patients with NAFLD who do not have obesity. Methods: PubMed was searched using the following keywords: nonobese......, dyslipidemia, NAFLD, NWD, liver, and metabolically obese/unhealthy normal weight. Additionally, article bibliographies were screened, and relevant citations were retrieved. Studies were excluded if they had not measured relevant biomarkers of dyslipidemia. Results: NWD and NAFLD without obesity share a similar...

  7. Gain weighted eigenspace assignment

    Science.gov (United States)

    Davidson, John B.; Andrisani, Dominick, II

    1994-01-01

    This report presents the development of the gain weighted eigenspace assignment methodology. This provides a designer with a systematic methodology for trading off eigenvector placement versus gain magnitudes, while still maintaining desired closed-loop eigenvalue locations. This is accomplished by forming a cost function composed of a scalar measure of error between desired and achievable eigenvectors and a scalar measure of gain magnitude, determining analytical expressions for the gradients, and solving for the optimal solution by numerical iteration. For this development the scalar measure of gain magnitude is chosen to be a weighted sum of the squares of all the individual elements of the feedback gain matrix. An example is presented to demonstrate the method. In this example, solutions yielding achievable eigenvectors close to the desired eigenvectors are obtained with significant reductions in gain magnitude compared to a solution obtained using a previously developed eigenspace (eigenstructure) assignment method.

  8. Calculating Quenching Weights

    CERN Document Server

    Salgado, C A; Salgado, Carlos A.; Wiedemann, Urs Achim

    2003-01-01

    We calculate the probability (``quenching weight'') that a hard parton radiates an additional energy fraction due to scattering in spatially extended QCD matter. This study is based on an exact treatment of finite in-medium path length, it includes the case of a dynamically expanding medium, and it extends to the angular dependence of the medium-induced gluon radiation pattern. All calculations are done in the multiple soft scattering approximation (Baier-Dokshitzer-Mueller-Peign\\'e-Schiff--Zakharov ``BDMPS-Z''-formalism) and in the single hard scattering approximation (N=1 opacity approximation). By comparison, we establish a simple relation between transport coefficient, Debye screening mass and opacity, for which both approximations lead to comparable results. Together with this paper, a CPU-inexpensive numerical subroutine for calculating quenching weights is provided electronically. To illustrate its applications, we discuss the suppression of hadronic transverse momentum spectra in nucleus-nucleus colli...

  9. On Weighted Support Vector Regression

    DEFF Research Database (Denmark)

    Han, Xixuan; Clemmensen, Line Katrine Harder

    2014-01-01

    We propose a new type of weighted support vector regression (SVR), motivated by modeling local dependencies in time and space in prediction of house prices. The classic weights of the weighted SVR are added to the slack variables in the objective function (OF‐weights). This procedure directly...

  10. Locally Weighted Naive Bayes

    OpenAIRE

    Frank, Eibe; Hall, Mark; Pfahringer, Bernhard

    2012-01-01

    Despite its simplicity, the naive Bayes classifier has surprised machine learning researchers by exhibiting good performance on a variety of learning problems. Encouraged by these results, researchers have looked to overcome naive Bayes primary weakness - attribute independence - and improve the performance of the algorithm. This paper presents a locally weighted version of naive Bayes that relaxes the independence assumption by learning local models at prediction time. Experimental results s...

  11. Intrapartum sonographic weight estimation.

    Science.gov (United States)

    Faschingbauer, F; Dammer, U; Raabe, E; Schneider, M; Faschingbauer, C; Schmid, M; Schild, R L; Beckmann, M W; Kehl, S; Mayr, A

    2015-10-01

    To evaluate the accuracy of intrapartum sonographic weight estimation (WE). This retrospective, cross-sectional study included 1958 singleton pregnancies. Inclusion criteria were singleton pregnancy with cephalic presentation, vaginal delivery and ultrasound examination with complete biometric parameters performed on the day of delivery during the latent or active phase of labor, and absence of chromosomal or structural anomalies. The accuracy of intrapartum WE was compared to a control group of fetuses delivered by primary cesarean section at our perinatal center and an ultrasound examination with complete biometric parameters performed within 3 days before delivery (n = 392). Otherwise, the same inclusion criteria as in the study group were applied. The accuracy of WE was compared between five commonly applied formulas using means of percentage errors (MPE), medians of absolute percentage errors (MAPE), and proportions of estimates within 10 % of actual birth weight. In the whole study group, all equations showed a systematic underestimation of fetal weight (negative MPEs). Overall, best MAPE and MPE values were found with the Hadlock II formula, using BPD, AC and FL as biometric parameters (Hadlock II, MPE: -1.28; MAPE: 6.52). MPEs differed significantly between WE in the study and control group for all evaluated formulas: in the control group, either no systematic error (Hadlock III, IV and V) or a significant overestimation (Hadlock I, II) was found. Regarding MAPEs, application of the Hadlock III (HC, AC, FL) and V (AC) formula resulted in significant lower values in the control group (Hadlock III, MAPE: 7.48 vs. 5.95, p = 0.0008 and Hadlock V, MAPE: 8.79 vs. 7.52, p = 0.0085). No significant differences were found for the other equations. A systematic underestimation of fetal weight has to be taken into account in sonographic WE performed intrapartum. Overall, the best results can be achieved with WE formulas using the BPD as the only head

  12. Weight rhythms: weight increases during weekends and decreases during weekdays.

    Science.gov (United States)

    Orsama, Anna-Leena; Mattila, Elina; Ermes, Miikka; van Gils, Mark; Wansink, Brian; Korhonen, Ilkka

    2014-01-01

    The week's cycle influences sleep, exercise, and eating habits. An accurate description of weekly weight rhythms has not been reported yet - especially across people who lose weight versus those who maintain or gain weight. The daily weight in 80 adults (BMI 20.0-33.5 kg/m(2); age, 25-62 years) was recorded and analysed to determine if a group-level weekly weight fluctuation exists. This was a retrospective study of 4,657 measurements during 15-330 monitoring days. Semi-parametric regression was used to model the rhythm. A pattern of daily weight changes was found (p < 0.05), with higher weight early in the week (Sunday and Monday) and decreasing weight during the week. Increases begin on Saturday and decreases begin on Tuesday. This compensation pattern was strongest for those who lost or maintained weight and weakest for those who slowly gained weight. Weight variations between weekends and weekdays should be considered as normal instead of signs of weight gain. Those who compensate the most are most likely to either lose or maintain weight over time. Long-term habits may make more of a difference than short-term splurges. People prone to weight gain could be counselled about the importance of weekday compensation. © 2014 S. Karger GmbH, Freiburg.

  13. Marital status and body weight, weight perception, and weight management among U.S. adults.

    Science.gov (United States)

    Klos, Lori A; Sobal, Jeffery

    2013-12-01

    Married individuals often have higher body weights than unmarried individuals, but it is unclear how marital roles affect body weight-related perceptions, desires, and behaviors. This study analyzed cross-sectional data for 4,089 adult men and 3,989 adult women using multinomial logistic regression to examine associations between marital status, perceived body weight, desired body weight, and weight management approach. Controlling for demographics and current weight, married or cohabiting women and divorced or separated women more often perceived themselves as overweight and desired to weigh less than women who had never married. Marital status was unrelated to men's weight perception and desired weight change. Marital status was also generally unrelated to weight management approach, except that divorced or separated women were more likely to have intentionally lost weight within the past year compared to never married women. Additionally, never married men were more likely to be attempting to prevent weight gain than married or cohabiting men and widowed men. Overall, married and formerly married women more often perceived themselves as overweight and desired a lower weight. Men's marital status was generally unassociated with weight-related perceptions, desires, and behaviors. Women's but not men's marital roles appear to influence their perceived and desired weight, suggesting that weight management interventions should be sensitive to both marital status and gender differences. © 2013 Elsevier Ltd. All rights reserved.

  14. Weight Advice Associated With Male Firefighter Weight Perception and Behavior.

    Science.gov (United States)

    Brown, Austin L; Poston, Walker S C; Jahnke, Sara A; Haddock, C Keith; Luo, Sheng; Delclos, George L; Day, R Sue

    2015-10-01

    The high prevalence of overweight and obesity threatens the health and safety of the fire service. Healthcare professionals may play an important role in helping firefighters achieve a healthy weight by providing weight loss counseling to at-risk firefighters. This study characterizes the impact of healthcare professional weight loss advice on firefighter weight perceptions and weight loss behaviors among overweight and obese male firefighters. A national sample of 763 overweight and obese male firefighters who recalled visiting a healthcare provider in the past 12 months reported information regarding healthcare visits, weight perceptions, current weight loss behaviors, and other covariates in 2011-2012. Analyzed in 2013, four unique multilevel logistic regression models estimated the association between healthcare professional weight loss advice and the outcomes of firefighter-reported weight perceptions, intentions to lose weight, reduced caloric intake, and increased physical activity. Healthcare professional weight loss advice was significantly associated with self-perception as overweight (OR=4.78, 95% CI=2.16, 10.57) and attempted weight loss (OR=2.06, 95% CI=1.25, 3.38), but not significantly associated with reduced caloric intake (OR=1.26, 95% CI=0.82, 1.95) and increased physical activity (OR=1.51, 95% CI=0.89, 2.61), after adjusting for confounders. Healthcare professional weight loss advice appears to increase the accuracy of firefighter weight perceptions, promote weight loss attempts, and may encourage dieting and physical activity behaviors among overweight firefighters. Healthcare providers should acknowledge their ability to influence the health behaviors of overweight and obese patients and make efforts to increase the quality and frequency of weight loss recommendations for all firefighters. Copyright © 2015 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

  15. Weighted triangulation adjustment

    Science.gov (United States)

    Anderson, Walter L.

    1969-01-01

    The variation of coordinates method is employed to perform a weighted least squares adjustment of horizontal survey networks. Geodetic coordinates are required for each fixed and adjustable station. A preliminary inverse geodetic position computation is made for each observed line. Weights associated with each observed equation for direction, azimuth, and distance are applied in the formation of the normal equations in-the least squares adjustment. The number of normal equations that may be solved is twice the number of new stations and less than 150. When the normal equations are solved, shifts are produced at adjustable stations. Previously computed correction factors are applied to the shifts and a most probable geodetic position is found for each adjustable station. Pinal azimuths and distances are computed. These may be written onto magnetic tape for subsequent computation of state plane or grid coordinates. Input consists of punch cards containing project identification, program options, and position and observation information. Results listed include preliminary and final positions, residuals, observation equations, solution of the normal equations showing magnitudes of shifts, and a plot of each adjusted and fixed station. During processing, data sets containing irrecoverable errors are rejected and the type of error is listed. The computer resumes processing of additional data sets.. Other conditions cause warning-errors to be issued, and processing continues with the current data set.

  16. Maternal characteristics influencing birth weight and infant weight ...

    African Journals Online (AJOL)

    At 6 weeks, 27.1% of infants failed to gain weight as expected for their age. Similarly, 37.0% of infants born to mothers with some tertiary education showed slowed weight gain compared with those who had secondary (19.2%) or primary (14.7%) education, P=0.03. Maternal weight at delivery positively correlated with birth ...

  17. Weighted Branching Simulation Distance for Parametric Weighted Kripke Structures

    DEFF Research Database (Denmark)

    Foshammer, Louise; Larsen, Kim Guldstrand; Mariegaard, Anders

    2016-01-01

    This paper concerns branching simulation for weighted Kripke structures with parametric weights. Concretely, we consider a weighted extension of branching simulation where a single transitions can be matched by a sequence of transitions while preserving the branching behavior. We relax this notion...

  18. Weighted composition operators on weighted Bergman spaces of ...

    Indian Academy of Sciences (India)

    In this paper, we study the weighted compositon operators on weighted Bergman spaces of bounded symmetric domains. The necessary and sufficient conditions for a weighted composition operator W φ , ψ to be bounded and compact are studied by using the Carleson measure techniques. In the last section, we study the ...

  19. Weighted composition operators on weighted Bergman spaces of ...

    Indian Academy of Sciences (India)

    Abstract. In this paper, we study the weighted compositon operators on weighted. Bergman spaces of bounded symmetric domains. The necessary and sufficient conditions for a weighted composition operator Wϕ,ψ to be bounded and compact are studied by using the Carleson measure techniques. In the last section, we ...

  20. Prevalence of metabolic syndrome using weight and weight indices ...

    African Journals Online (AJOL)

    Prevalence of metabolic syndrome using weight and weight indices in an apparently healthy Nigerian population. ISI Ogbu, EE Chukwukelu. Abstract. Background: Notions about the metabolic syndrome (MS) emphasized the importance of obesity. This may prevent the early diagnosis of the condition in normal weight ...

  1. Prevalence of metabolic syndrome using weight and weight indices ...

    African Journals Online (AJOL)

    McRoy

    Background: Notions about the metabolic syndrome (MS) emphasized the importance of obesity. This may prevent the early diagnosis of the condition in normal weight individuals. Aim: To determine variations in prevalence of MS according to different weight and weight indices. Materials and Methods: 342 apparently ...

  2. What determines hatchling weight: breeder age or incubated egg weight?

    Directory of Open Access Journals (Sweden)

    AB Traldi

    2011-12-01

    Full Text Available Two experiments were carried out to determine which factor influences weight at hatch of broiler chicks: breeder age or incubated egg weight. In Experiment 1, 2340 eggs produced by 29- and 55-week-old Ross® broiler breeders were incubated. The eggs selected for incubation weighed one standard deviation below and above average egg weight. In Experiment 2, 2160 eggs weighing 62 g produced by breeders of both ages were incubated. In both experiments, 50 additional eggs within the weight interval determined for each breeder age were weighed, broken, and their components were separated and weighed. At hatch, hatchlings were sexed and weighed, determining the average initial weight of the progeny of each breeder age. Data were analyzed using the Analyst program of SAS® software package. In Experiment 1, the weight difference between eggs produced by young and mature breeders was 10.92 g, and the component that mostly influenced this difference was the yolk (7.51 g heavier in mature breeders, compared with 4.23 g difference in albumen and 0.8 g in eggshell weights. Hatchling weight difference was 9.4 g higher in eggs from mature breeders. In Experiment 2, egg weight difference was only 0.74 g, but yolk weight was 4.59 g higher in the eggs of mature breeders. The results obtained in the present study indicate that hatchling weight is influenced by egg weight, and not by breeder age.

  3. The Influence of Weight Status Duration on Weight Perception Accuracy.

    Science.gov (United States)

    Coleman, Lois; Loprinzi, Paul D

    2018-03-01

    To examine the association between weight status duration and weight perception accuracy. Retrospective study. National Health and Nutrition Examination Survey 2003 to 2006. A total of 4029 adults aged 20 years or older. To assess weight status duration, participants' past (10 years ago) and present body mass indexes were used to create 4 groups: normal weight in the past and present (group 1), normal weight in the past but overweight/obese in the present (group 2), overweight/obese in the present but not in the past (group 3), and overweight/obese in the past and present (group 4). We classified individuals as having an accurate/inaccurate weight perception based on present body mass index and whether they considered themselves as overweight, underweight, or about the right weight. Logistic regression. Our findings suggest that participants who were overweight/obese in the past, present, or during both time periods had increased odds of possessing an inaccurate weight perception. Furthermore, being normal weight in the past but obese in the present increased the odds of having an inaccurate weight perception nearly 10-fold and almost 5-fold for those obese in both the past and present. Studies such as this can aid clinicians in identifying individuals who may have increased odds of inaccurately identifying their weight status, thereby providing additional opportunities to facilitate weight loss.

  4. Grappling with Weight Cutting. The Wisconsin Wrestling Minimum Weight Project.

    Science.gov (United States)

    Oppliger, Robert A.; And Others

    1995-01-01

    In response to a new state rule, the Wisconsin Minimum Weight Project curtails weight cutting among high school wrestlers. The project uses skinfold testing to determine a minimum competitive weight and nutrition education to help the wrestler diet safety. It serves as a model for other states and other sports. (Author/SM)

  5. Aim For a Healthy Weight

    Science.gov (United States)

    ... Institutes of Health Contact Us Get Email Alerts Font Size Accessible Search Form Search the NHLBI, use ... Be Physically Active Healthy Weight Tools BMI Calculator Menu Plans Portion Distortion Key Recommendations Healthy Weight Resources ...

  6. Diet for rapid weight loss

    Science.gov (United States)

    ... each day. A VLCD is only recommended for adults who are obese and need to lose weight for health reasons. These diets are often used before weight-loss surgery. You should only use a VLCD with ...

  7. Human biology of weight maintenance after weight loss.

    Science.gov (United States)

    Mariman, Edwin C M

    2012-01-01

    One year after losing weight, most people have regained a significant part of the lost weight. As such, weight regain after weight loss has a negative impact on human health. The risk for weight regain is determined by psychosocial and behavioral factors as well as by various physiological and molecular parameters. Here, the latter intrinsic factors are reviewed and assembled into four functional modules, two related to the energy balance and two related to resistance against weight loss. Reported genetic factors do not reveal additional functional processes. The modules form nodes in a network describing the complex interactions of intrinsically determined weight maintenance. This network indicates that after an initial weight loss persons with a high baseline fat mass will most easily succeed in maintaining weight, because they can lose fat without raising stress in adipocytes and at the same time spare fat-free mass. However, continued weight loss and weight maintenance requires extra measures like increased physical activity, limited energy intake and a fat-free sparing composition of the diet. Eventually, this network may help to design novel therapeutic measures based on preventing the return effect of specific plasma factors or by preventing the accumulation of adipocyte cellular stress. Copyright © 2012 S. Karger AG, Basel.

  8. Hypnotherapy in Weight Loss Treatment.

    Science.gov (United States)

    Cochrane, Gordon; Friesen, John

    1986-01-01

    Investigated effects of hypnosis as a treatment for weight loss among women. The primary hypothesis that hypnosis is an effective treatment for weight loss was confirmed, but seven concomitant variables and the use of audiotapes were not significant contributors to weight loss. (Author/ABB)

  9. Fungible Weights in Multiple Regression

    Science.gov (United States)

    Waller, Niels G.

    2008-01-01

    Every set of alternate weights (i.e., nonleast squares weights) in a multiple regression analysis with three or more predictors is associated with an infinite class of weights. All members of a given class can be deemed "fungible" because they yield identical "SSE" (sum of squared errors) and R[superscript 2] values. Equations for generating…

  10. Link prediction in weighted networks

    DEFF Research Database (Denmark)

    Wind, David Kofoed; Mørup, Morten

    2012-01-01

    Many complex networks feature relations with weight information. Some models utilize this information while other ignore the weight information when inferring the structure. In this paper we investigate if edge-weights when modeling real networks, carry important information about the network...

  11. On weighted dyadic Carleson's inequalities

    Directory of Open Access Journals (Sweden)

    Tachizawa K

    2001-01-01

    Full Text Available We give an alternate proof of weighted dyadic Carleson's inequalities which are essentially proved by Sawyer and Wheeden. We use the Bellman function approach of Nazarov and Treil. As an application we give an alternate proof of weighted inequalities for dyadic fractional maximal operators. A result on weighted inequalities for fractional integral operators is given.

  12. Some Environmental Factors Affecting Birth Weight, Weaning Weight and Daily Live Weight Gain of Holstein Calves

    Directory of Open Access Journals (Sweden)

    Erdal Yaylak

    2015-07-01

    Full Text Available The present study was conducted to determine some environmental factors affecting birth weight, weaning weight and daily live weight gain of Holstein calves of a livestock facility in Izmir, Turkey. The data on 2091 calves born between the years 2005-2010 were used to assess the relevant parameters. Effects of calving year, calving month, calf gender and the interaction between calving year and calving month on calves’ birth weights were highly significant. The overall mean of birth weights was 39.6±0.15 kg. In addition, effects of calving year, calving month, gender, birth weight, weaning age, calving year x calving month, calving year x gender and calving year x calving month x gender interactions on weaning weight (WW and daily live weight gain (DLWG were highly significant. The overall means of WW and DLWG were respectively found to be 79.7±0.20 kg and 525±2.5 g. A one kilogram increase in birth weight resulted in an increase of 0.89 kg in weaning weight and a decrease of 1.26 g in daily live weight gain. Prenatal temperature-humidity index (THI affected birth weight of calves (R2=0.67. Increasing THI from 50 to 80 resulted in 3.8 kg decrease in birth weight.

  13. Physiological adaptations to weight loss and factors favouring weight regain.

    Science.gov (United States)

    Greenway, F L

    2015-08-01

    Obesity is a major global health problem and predisposes individuals to several comorbidities that can affect life expectancy. Interventions based on lifestyle modification (for example, improved diet and exercise) are integral components in the management of obesity. However, although weight loss can be achieved through dietary restriction and/or increased physical activity, over the long term many individuals regain weight. The aim of this article is to review the research into the processes and mechanisms that underpin weight regain after weight loss and comment on future strategies to address them. Maintenance of body weight is regulated by the interaction of a number of processes, encompassing homoeostatic, environmental and behavioural factors. In homoeostatic regulation, the hypothalamus has a central role in integrating signals regarding food intake, energy balance and body weight, while an 'obesogenic' environment and behavioural patterns exert effects on the amount and type of food intake and physical activity. The roles of other environmental factors are also now being considered, including sleep debt and iatrogenic effects of medications, many of which warrant further investigation. Unfortunately, physiological adaptations to weight loss favour weight regain. These changes include perturbations in the levels of circulating appetite-related hormones and energy homoeostasis, in addition to alterations in nutrient metabolism and subjective appetite. To maintain weight loss, individuals must adhere to behaviours that counteract physiological adaptations and other factors favouring weight regain. It is difficult to overcome physiology with behaviour. Weight loss medications and surgery change the physiology of body weight regulation and are the best chance for long-term success. An increased understanding of the physiology of weight loss and regain will underpin the development of future strategies to support overweight and obese individuals in their efforts

  14. Physiological adaptations to weight loss and factors favouring weight regain

    Science.gov (United States)

    Greenway, F L

    2015-01-01

    Obesity is a major global health problem and predisposes individuals to several comorbidities that can affect life expectancy. Interventions based on lifestyle modification (for example, improved diet and exercise) are integral components in the management of obesity. However, although weight loss can be achieved through dietary restriction and/or increased physical activity, over the long term many individuals regain weight. The aim of this article is to review the research into the processes and mechanisms that underpin weight regain after weight loss and comment on future strategies to address them. Maintenance of body weight is regulated by the interaction of a number of processes, encompassing homoeostatic, environmental and behavioural factors. In homoeostatic regulation, the hypothalamus has a central role in integrating signals regarding food intake, energy balance and body weight, while an ‘obesogenic' environment and behavioural patterns exert effects on the amount and type of food intake and physical activity. The roles of other environmental factors are also now being considered, including sleep debt and iatrogenic effects of medications, many of which warrant further investigation. Unfortunately, physiological adaptations to weight loss favour weight regain. These changes include perturbations in the levels of circulating appetite-related hormones and energy homoeostasis, in addition to alterations in nutrient metabolism and subjective appetite. To maintain weight loss, individuals must adhere to behaviours that counteract physiological adaptations and other factors favouring weight regain. It is difficult to overcome physiology with behaviour. Weight loss medications and surgery change the physiology of body weight regulation and are the best chance for long-term success. An increased understanding of the physiology of weight loss and regain will underpin the development of future strategies to support overweight and obese individuals in their

  15. The relationship among registered nurses' weight status, weight loss regimens, and successful or unsuccessful weight loss.

    Science.gov (United States)

    Zitkus, Bruce S

    2011-02-01

    To investigate relationships between body mass index (BMI), personality type, weight loss regimens, and successful or unsuccessful weight loss. Seven hundred and twenty-one registered nurses (RNs) were recruited from the American Academy of Nurse Practitioners, the membership of a nursing honor society, and RNs at a large state university. Participants completed the Myers-Briggs Type Indicator (MBTI), a demographic survey (age, gender, height, weight, ethnicity, education status, disability, shift work hours, and prescription medication use), and questions related to their weight status, weight loss attempts, and motivation. RNs who had a lower BMI were more successful in losing weight than RNs who had a higher BMI. They were also more successful in their weight loss attempts if they did not use a diet regimen. RNs who were successful in losing weight did not use a specified dietary regimen. ©2011 The Author Journal compilation ©2011 American Academy of Nurse Practitioners.

  16. Social contagions on weighted networks

    Science.gov (United States)

    Zhu, Yu-Xiao; Wang, Wei; Tang, Ming; Ahn, Yong-Yeol

    2017-07-01

    We investigate critical behaviors of a social contagion model on weighted networks. An edge-weight compartmental approach is applied to analyze the weighted social contagion on strongly heterogenous networks with skewed degree and weight distributions. We find that degree heterogeneity cannot only alter the nature of contagion transition from discontinuous to continuous but also can enhance or hamper the size of adoption, depending on the unit transmission probability. We also show that the heterogeneity of weight distribution always hinders social contagions, and does not alter the transition type.

  17. The weight loss profile: a biopsychosocial approach to weight loss.

    Science.gov (United States)

    Feuerstein, M; Papciak, A; Shapiro, S; Tannenbaum, S

    1989-01-01

    Obesity is a common complicating condition in a variety of medical problems. Often effective consultation liaison involves recommendations to overweight patients involving lifestyle and health risk modification. Factors that need to be addressed include exercise, nutritional counseling/caloric restriction, and attitude and behavioral change regarding eating. Patients requiring weight loss typically seek various commercial programs that are readily accessible. One major problem associated with such programs is the high attrition rate within the first six weeks of initiation. Therefore, attempts to facilitate longer-term retention and associated weight loss are warranted. One approach is the identification of factors associated with problems in short-term retention and weight loss followed by the implementation of brief interventions to potentially reverse the influence of these factors on retention and weight loss. The present investigation was conducted to determine the effects of such a strategy on short-term retention and weight loss in a commercial weight loss program. Two groups (n = 66 per group) of female participants with a mean age of thirty-eight years, mean initial weight of 184.6 lbs, mean height of 64.3 inches, mean goal weight of 147.3 lbs, mean Body Mass Index of 31.4 kg/m2 were recruited for the study. Groups were matched for age, initial weight, height, goal weight, and body mass index. One group (controls) received a standard thirteen-week group cognitive-behavioral intervention that emphasized the teaching of self-management strategies for weight reduction. The second group (personalized intervention) received the same thirteen-week cognitive-behavioral intervention. This group also completed a questionnaire (Weight Loss Profile) that identifies factors associated with poor retention and minimal weight loss. Targeted interventions were implemented to modify specific problem areas identified on the Weight Loss Profile. The problem areas were based

  18. Weight Rhythms: Weight Increases during Weekends and Decreases during Weekdays

    Directory of Open Access Journals (Sweden)

    Anna-Leena Orsama

    2014-01-01

    Full Text Available Background/Aims: The week's cycle influences sleep, exercise, and eating habits. An accurate description of weekly weight rhythms has not been reported yet - especially across people who lose weight versus those who maintain or gain weight. Methods: The daily weight in 80 adults (BMI 20.0-33.5 kg/m2; age, 25-62 years was recorded and analysed to determine if a group-level weekly weight fluctuation exists. This was a retrospective study of 4,657 measurements during 15-330 monitoring days. Semi-parametric regression was used to model the rhythm. Results: A pattern of daily weight changes was found (p Conclusion: Weight variations between weekends and weekdays should be considered as normal instead of signs of weight gain. Those who compensate the most are most likely to either lose or maintain weight over time. Long-term habits may make more of a difference than short-term splurges. People prone to weight gain could be counselled about the importance of weekday compensation.

  19. Are normal-weight adolescents satisfied with their weight?

    Directory of Open Access Journals (Sweden)

    Mariana Contiero San Martini

    Full Text Available ABSTRACT: CONTEXT AND OBJECTIVE: The high prevalence of obesity has led to public policies for combating it. People with normal weight may gain greater awareness of this issue and change their perceptions of their weight. The aim of this study was to evaluate the prevalence of body weight dissatisfaction among normal-weight adolescents, according to demographic and socioeconomic variables, health-related behavior and morbidities. DESIGN AND SETTING: Population-based cross-sectional study that used data from a health survey conducted in the city of Campinas, São Paulo, in 2008-2009. METHODS: The prevalence and prevalence ratios of weight dissatisfaction were estimated according to independent variables, by means of simple and multiple Poisson regression. RESULTS: 573 normal-weight adolescents aged 10 to 19 years (mean age 14.7 years were analyzed. The prevalence of weight dissatisfaction was 43.7% (95% confidence interval, CI: 37.8-49.8. Higher prevalences of weight dissatisfaction were observed among females, individuals aged 15 to 19 years, those whose households had eight or more domestic appliances, former smokers, individuals who reported alcohol intake and those who had one or more chronic diseases. Lower prevalence of dissatisfaction was observed among adolescents living in substandard housing. Among the normal-weight adolescents, 26.1% wished to lose weight and 17.6% wished to gain weight. CONCLUSION: The results from this study indicate that even when weight is seen to be within the normal range, a high proportion of adolescents express dissatisfaction with their weight, especially females, older adolescents and those of higher socioeconomic level.

  20. Some observations on weighted GMRES

    KAUST Repository

    Güttel, Stefan

    2014-01-10

    We investigate the convergence of the weighted GMRES method for solving linear systems. Two different weighting variants are compared with unweighted GMRES for three model problems, giving a phenomenological explanation of cases where weighting improves convergence, and a case where weighting has no effect on the convergence. We also present a new alternative implementation of the weighted Arnoldi algorithm which under known circumstances will be favourable in terms of computational complexity. These implementations of weighted GMRES are compared for a large number of examples. We find that weighted GMRES may outperform unweighted GMRES for some problems, but more often this method is not competitive with other Krylov subspace methods like GMRES with deflated restarting or BICGSTAB, in particular when a preconditioner is used. © 2014 Springer Science+Business Media New York.

  1. Heterotic weight lifting

    Energy Technology Data Exchange (ETDEWEB)

    Gato-Rivera, B. [NIKHEF Theory Group, Kruislaan 409, 1098 SJ Amsterdam (Netherlands); Instituto de Fisica Fundamental, CSIC, Serrano 123, Madrid 28006 (Spain); Schellekens, A.N., E-mail: t58@nikhef.n [NIKHEF Theory Group, Kruislaan 409, 1098 SJ Amsterdam (Netherlands); Instituto de Fisica Fundamental, CSIC, Serrano 123, Madrid 28006 (Spain); IMAPP, Radboud Universiteit, Nijmegen (Netherlands)

    2010-03-21

    We describe a method for constructing genuinely asymmetric (2,0) heterotic strings out of N=2 minimal models in the fermionic sector, whereas the bosonic sector is only partly build out of N=2 minimal models. This is achieved by replacing one minimal model plus the superfluous E{sub 8} factor by a non-supersymmetric CFT with identical modular properties. This CFT generically lifts the weights in the bosonic sector, giving rise to a spectrum with fewer massless states. We identify more than 30 such lifts, and we expect many more to exist. This yields more than 450 different combinations. Remarkably, despite the lifting of all Ramond states, it is still possible to get chiral spectra. Even more surprisingly, these chiral spectra include examples with a certain number of chiral families of SO(10), SU(5) or other subgroups, including just SU(3)xSU(2)xU(1). The number of families and mirror families is typically smaller than in standard Gepner models. Furthermore, in a large number of different cases, spectra with three chiral families can be obtained. Based on a first scan of about 10% of the lifted Gepner models we can construct, we have collected more than 10,000 distinct spectra with three families, including examples without mirror fermions. We present an example where the GUT group is completely broken to the standard model, but the resulting and inevitable fractionally charged particles are confined by an additional gauge group factor.

  2. Global coordination: weighted voting

    Directory of Open Access Journals (Sweden)

    Jan-Erik Lane

    2014-03-01

    Full Text Available In order to halt the depletion of global ecological capital, a number of different kinds of meetings between Governments of countries in the world has been scheduled. The need for global coordination of environmental policies has become ever more obvious, supported by more and more evidence of the running down of ecological capital. But there are no formal or binding arrangements in sight, as global environmental coordination suffers from high transaction costs (qualitative voting. The CO2 equivalent emissions, resulting in global warming, are driven by the unstoppable economic expansion in the global market economy, employing mainly fossil fuel generated energy, although at the same time lifting sharply the GDP per capita of several emerging countries. Only global environmental coordination on the successful model of the World Band and the IMF (quantitative voting can stem the rising emissions numbers and stop further environmental degradation. However, the system of weighted voting in the WB and the IMF must be reformed by reducing the excessive voting power disparities, for instance by reducing all member country votes by the cube root expression.

  3. Association between maternal weight gain and birth weight

    DEFF Research Database (Denmark)

    Rode, Line; Hegaard, Hanne K; Kjaergaard, Hanne

    2007-01-01

    To investigate the association between maternal weight gain and birth weight less than 3,000 g and greater than or equal to 4,000 g in underweight (body mass index [BMI] less than 19.8 kg/m(2)), normal weight (BMI 19.8-26.0 kg/m(2)), overweight (BMI 26.1-29.0 kg/m(2)), and obese (BMI greater than...

  4. Regulatory Focus, Proximity to Goal Weight, and Weight Loss Maintenance.

    Science.gov (United States)

    Fuglestad, Paul T; Rothman, Alexander J; Jeffery, Robert W; Sherwood, Nancy E

    2015-09-01

    Regulatory focus theory proposes 2 self-regulatory orientations: promotion focus - related to achieving aspirations and positive outcomes - and prevention focus - related to fulfilling responsibilities and preventing negative outcomes. The investigation examined whether regulatory focus and proximity to goal weight moderated the effectiveness of a weight-loss maintenance intervention. Participants who lost ≥10% of their weight were assigned to guided or self-directed treatments and completed regulatory focus and weight goal measures. Across treatment groups, people who were more promotion-focused had better 2-year maintenance rates (defined as regain focused, especially if far from their goal weight (.59 versus .44). In the guided group, people who were more prevention-focused had better maintenance rates than people who were less prevention-focused if closer to their goal weight (.69 versus .42), but poorer maintenance rates if farther from their goal (.36 versus .72). In the self-directed group, prevention focus was unrelated to maintenance. Regulatory focus and proximity to goal weight moderated intervention effectiveness. Maintenance may be enhanced by tailoring treatments to regulatory focus and goal weight (eg, prevention-focused people far from their goals may need extra weight-loss support before focusing on maintenance).

  5. What is the strongest predictor of birth weight: Gestational age, hbalc, maternal weight, weight gain, or birth weight of sibling?

    DEFF Research Database (Denmark)

    Nielsen, Gunnar Lauge; Dethlefsen, Claus

    Aim: To assess the effect of various maternal characteristics in diabetic pregnancies on birthweight (BW) taking into account birthweight of an elderly sibling.  Method: We identified all pregnant diabetic women in North Jutland County. Birthweight and certain maternal characteristics including Hb......A1c values after 20th gestational week were collected. Multiple regression models were fitted to assess the effect various predictors of birthweight in both entire cohort (n=501) and in a subset with available weight of sibling (n=139). Sibling weight was calculated as relative to expected weight...... adjusted for age and sex using a Danish reference. E.g. an observed sibling weight of 3800 g with expected BW 3400 g predicts 11.8% extra weight equal to 134 grams (114x11.8) and one extra gestational day predicts an additional weight of 27 grams.  Results: The effects in terms of additional grams in BW...

  6. The weighted random graph model

    Science.gov (United States)

    Garlaschelli, Diego

    2009-07-01

    We introduce the weighted random graph (WRG) model, which represents the weighted counterpart of the Erdos-Renyi random graph and provides fundamental insights into more complicated weighted networks. We find analytically that the WRG is characterized by a geometric weight distribution, a binomial degree distribution and a negative binomial strength distribution. We also characterize exactly the percolation phase transitions associated with edge removal and with the appearance of weighted subgraphs of any order and intensity. We find that even this completely null model displays a percolation behaviour similar to what is observed in real weighted networks, implying that edge removal cannot be used to detect community structure empirically. By contrast, the analysis of clustering successfully reveals different patterns between the WRG and real networks.

  7. Microbiota manipulation for weight change.

    Science.gov (United States)

    Dror, Tal; Dickstein, Yaakov; Dubourg, Grégory; Paul, Mical

    2017-05-01

    Manipulation of the intestinal microbiota has been linked to weight changes and obesity. To explore the influence of specific agents that alter the intestinal flora on weight in different patient groups we conducted a meta-analysis of randomized controlled trials (RCTs) reporting on the effects of probiotics, prebiotics, synbiotics, and antibiotics on weight. We searched the Pubmed and Cochrane Library databases for trials on adults, children, and infants evaluating the effects of these substances on weight. Our primary outcome was weight change from baseline. Standardized mean differences (SMDs) with 95% confidence intervals were calculated. We identified and included 13 adult, 17 children, and 23 infant RCTs. Effects were opposite among adults and children, showing weight loss among adults (SMD -0.54 [-0.83, -0.25)) and minor weight gains among children (SMD 0.20 [0.04, 0.36]) and infants (SMD 0.30 [-0.01, 0.62]) taking mainly Lactobacillus probiotic supplements. Heterogeneity was substantial in the adult and infant analyses and could not be explained by intervention or patient characteristics. Azithromycin administration in children with pulmonary disease was associated with weight gain (SMD 0.39 [0.24, 0.54]), without heterogeneity. A high risk of selective reporting and attrition bias was detected across the studies, making it difficult to draw firm conclusions. Overall, our meta-analysis suggests that there may be a role for probiotics in promoting weight loss in adults and weight gain in children, however additional studies are needed. Though we cannot recommend antibiotic administration for weight manipulation, its use provides advantageous weight gain in children with cystic fibrosis and bronchiectasis. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. variances for reproduction, egg weight and chick weight in ostriches

    African Journals Online (AJOL)

    Schalk Cloete

    Peer-reviewed paper: Joint South African Society for Animal Science/Grassland Society of Southern Africa Congress. 19. Reproduction traits were generally positively related to egg and chick weight on a genetic level (Table. 2), although only the correlations involving egg weight were significant. These results accords with ...

  9. Socioeconomic Disparities in Emerging Adult Weight and Weight Behaviors

    Science.gov (United States)

    VanKim, Nicole A.; Laska, Melissa N.

    2012-01-01

    Objectives: To explore weight, weight behaviors, and tobacco and alcohol use among emerging adults by parental education and financial strain. Methods: Cross-sectional analyses of 2010 survey data from an urban Minnesota public 4-year university and 2-year community college (n=1201). Results: Low parental education was associated with lower…

  10. Length-weight relationships, condition factors and relative weight of ...

    African Journals Online (AJOL)

    The aim of this study was to record the length-weight relationship parameters and condition factors for some commercially important fish of Bushehr coastal waters of Persian Gulf. The length-weight relationships were calculated for five species caught during fishing surveys using different types of fishing gears (trawls, pots ...

  11. Variation in Body Weight, Organ Weight and Haematological ...

    African Journals Online (AJOL)

    The rats fed raw kudzu and negative control diet showed negative mean weight changes(- 6.50g and -10.0g )while those fed with positive control and treated kudzu diet showed positive mean weight changes with Diets 2(cooked kudzu) and Diet 8(positive control) having the highest values(55.10g and 90.0g).

  12. All rights reserved Variation in Body Weight, Organ Weight and ...

    African Journals Online (AJOL)

    ADOWIE PERE

    www.ajol.info and www.bioline.org.br/ja. Variation in Body Weight, Organ Weight and Haematological Parameters of Rats Fed with Diets Based on Treated ... nutritional quality. Some processing methods including dry heat and wet heat treatment, soaking, dehulling, fermentation, sprouting etc. have been used in the past.

  13. Effect of sibutramine on weight maintenance after weight loss

    DEFF Research Database (Denmark)

    James, W P; Astrup, A; Finer, Nicholas

    2000-01-01

    Sibutramine is a tertiary amine that has been shown to induce dose-dependent weight loss and to enhance the effects of a low-calorie diet for up to a year. We did a randomised, double-blind trial to assess the usefulness of sibutramine in maintaining substantial weight loss over 2 years....

  14. Simulations of multi-contrast x-ray imaging using near-field speckles

    Energy Technology Data Exchange (ETDEWEB)

    Zdora, Marie-Christine [Lehrstuhl für Biomedizinische Physik, Physik-Department & Institut für Medizintechnik, Technische Universität München, 85748 Garching (Germany); Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire, OX11 0DE, United Kingdom and Department of Physics & Astronomy, University College London, London, WC1E 6BT (United Kingdom); Thibault, Pierre [Department of Physics & Astronomy, University College London, London, WC1E 6BT (United Kingdom); Herzen, Julia; Pfeiffer, Franz [Lehrstuhl für Biomedizinische Physik, Physik-Department & Institut für Medizintechnik, Technische Universität München, 85748 Garching (Germany); Zanette, Irene [Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire, OX11 0DE (United Kingdom); Lehrstuhl für Biomedizinische Physik, Physik-Department & Institut für Medizintechnik, Technische Universität München, 85748 Garching (Germany)

    2016-01-28

    X-ray dark-field and phase-contrast imaging using near-field speckles is a novel technique that overcomes limitations inherent in conventional absorption x-ray imaging, i.e. poor contrast for features with similar density. Speckle-based imaging yields a wealth of information with a simple setup tolerant to polychromatic and divergent beams, and simple data acquisition and analysis procedures. Here, we present a simulation software used to model the image formation with the speckle-based technique, and we compare simulated results on a phantom sample with experimental synchrotron data. Thorough simulation of a speckle-based imaging experiment will help for better understanding and optimising the technique itself.

  15. Stress, race, and body weight.

    Science.gov (United States)

    Kim, Karen Hye-cheon; Bursac, Zoran; DiLillo, Vicki; White, Della Brown; West, Delia Smith

    2009-01-01

    Stress has been identified as a significant factor in health and in racial/ethnic health disparities. A potential mediator in these relationships is body weight. Cross-sectional and longitudinal relationships between stress, race, and body weight were examined in an ethnically diverse sample of overweight and obese women with Type 2 diabetes (n = 217) enrolled in a behavioral weight loss program. Stress (Perceived Stress Scale) was assessed at baseline only and body weight (body mass index) was assessed at baseline and 6 months. Stress was not related to baseline body weight. With every 1 unit lower scored on the baseline stress measure, women lost 0.10 kg +/- .04 more at 6 months (p women were divided into tertiles based on baseline stress scores, those in the lowest stress group had significantly greater weight loss (5.2 kg +/- 4.9) compared with those in the highest stress group (3.0 kg +/- 4.0) (p weight loss has implications for enhancing weight loss programs for women with Type 2 diabetes. (c) 2009 APA, all rights reserved.

  16. Asymptotics of weighted random sums

    DEFF Research Database (Denmark)

    Corcuera, José Manuel; Nualart, David; Podolskij, Mark

    2014-01-01

    In this paper we study the asymptotic behaviour of weighted random sums when the sum process converges stably in law to a Brownian motion and the weight process has continuous trajectories, more regular than that of a Brownian motion. We show that these sums converge in law to the integral...

  17. Polynomial weights and code constructions

    DEFF Research Database (Denmark)

    Massey, J; Costello, D; Justesen, Jørn

    1973-01-01

    For any nonzero elementcof a general finite fieldGF(q), it is shown that the polynomials(x - c)^i, i = 0,1,2,cdots, have the "weight-retaining" property that any linear combination of these polynomials with coefficients inGF(q)has Hamming weight at least as great as that of the minimum degree...

  18. Proportioning of light weight concrete

    DEFF Research Database (Denmark)

    Palmus, Lars

    1996-01-01

    Development of a method to determine the proportions of the raw materials in light weight concrete made with leight expanded clay aggregate. The method is based on composite theory......Development of a method to determine the proportions of the raw materials in light weight concrete made with leight expanded clay aggregate. The method is based on composite theory...

  19. Fuzzy Weighted Average: Analytical Solution

    NARCIS (Netherlands)

    van den Broek, P.M.; Noppen, J.A.R.

    2009-01-01

    An algorithm is presented for the computation of analytical expressions for the extremal values of the α-cuts of the fuzzy weighted average, for triangular or trapeizoidal weights and attributes. Also, an algorithm for the computation of the inverses of these expressions is given, providing exact

  20. PHENOTYPIC CORRELATIONS AND BODY WEIGHTS ...

    African Journals Online (AJOL)

    Dr Osondu

    because of its high meat quality and acceptance by ... respectively. Thus, morphometric traits were recommended by Okon et al. (2010a, b) as good predictors of hatchling weights in. Department of Animal Science, University of Calabar, .... wt = body weight, w = hatchling body shell width, L = hatchling body shell length.

  1. Nonparametric weighted stochastic block models

    Science.gov (United States)

    Peixoto, Tiago P.

    2018-01-01

    We present a Bayesian formulation of weighted stochastic block models that can be used to infer the large-scale modular structure of weighted networks, including their hierarchical organization. Our method is nonparametric, and thus does not require the prior knowledge of the number of groups or other dimensions of the model, which are instead inferred from data. We give a comprehensive treatment of different kinds of edge weights (i.e., continuous or discrete, signed or unsigned, bounded or unbounded), as well as arbitrary weight transformations, and describe an unsupervised model selection approach to choose the best network description. We illustrate the application of our method to a variety of empirical weighted networks, such as global migrations, voting patterns in congress, and neural connections in the human brain.

  2. When does weight matter most?

    Science.gov (United States)

    Chen, Alice J

    2012-01-01

    Past empirical work establishes a wage penalty from being overweight. In this paper, I exploit variation in an individual's weight over time to determine the age when weight has the largest impact on labor market outcomes. For white men, controlling for weight at younger ages does not eliminate the effect of older adult weight on wage: being overweight as a young adult only adds an additional penalty to adult wages. However, for white women, what they weigh in their early twenties solely determines the existence of an adult wage penalty. The female early-twenties weight penalty has a persistent effect on wages, and differences in marital characteristics, occupation status, or education cannot explain it. It also is not a proxy for intergenerational unobservables. Copyright © 2011 Elsevier B.V. All rights reserved.

  3. Perceived weight discrimination and obesity.

    Directory of Open Access Journals (Sweden)

    Angelina R Sutin

    Full Text Available Weight discrimination is prevalent in American society. Although associated consistently with psychological and economic outcomes, less is known about whether weight discrimination is associated with longitudinal changes in obesity. The objectives of this research are (1 to test whether weight discrimination is associated with risk of becoming obese (Body Mass Index≥30; BMI by follow-up among those not obese at baseline, and (2 to test whether weight discrimination is associated with risk of remaining obese at follow-up among those already obese at baseline. Participants were drawn from the Health and Retirement Study, a nationally representative longitudinal survey of community-dwelling US residents. A total of 6,157 participants (58.6% female completed the discrimination measure and had weight and height available from the 2006 and 2010 assessments. Participants who experienced weight discrimination were approximately 2.5 times more likely to become obese by follow-up (OR = 2.54, 95% CI = 1.58-4.08 and participants who were obese at baseline were three times more likely to remain obese at follow up (OR = 3.20, 95% CI = 2.06-4.97 than those who had not experienced such discrimination. These effects held when controlling for demographic factors (age, sex, ethnicity, education and when baseline BMI was included as a covariate. These effects were also specific to weight discrimination; other forms of discrimination (e.g., sex, race were unrelated to risk of obesity at follow-up. The present research demonstrates that, in addition to poorer mental health outcomes, weight discrimination has implications for obesity. Rather than motivating individuals to lose weight, weight discrimination increases risk for obesity.

  4. Long-term weight loss maintenance

    National Research Council Canada - National Science Library

    Wing, Rena R; Phelan, Suzanne

    2005-01-01

    ...% of initial body weight and maintaining the loss for at least 1 y. The National Weight Control Registry provides information about the strategies used by successful weight loss maintainers to achieve and maintain long-term weight loss...

  5. Combination contraceptives: effects on weight.

    Science.gov (United States)

    Gallo, Maria F; Lopez, Laureen M; Grimes, David A; Carayon, Florence; Schulz, Kenneth F; Helmerhorst, Frans M

    2014-01-29

    Weight gain is often considered a side effect of combination hormonal contraceptives, and many women and clinicians believe that an association exists. Concern about weight gain can limit the use of this highly effective method of contraception by deterring the initiation of its use and causing early discontinuation among users. However, a causal relationship between combination contraceptives and weight gain has not been established. The aim of the review was to evaluate the potential association between combination contraceptive use and changes in weight. In November 2013, we searched the computerized databases CENTRAL (The Cochrane Library), MEDLINE, POPLINE, EMBASE, and LILACS for studies of combination contraceptives, as well as ClinicalTrials.gov and International Clinical Trials Registry Platform (ICTRP). For the initial review, we also wrote to known investigators and manufacturers to request information about other published or unpublished trials not discovered in our search. All English-language, randomized controlled trials were eligible if they had at least three treatment cycles and compared a combination contraceptive to a placebo or to a combination contraceptive that differed in drug, dosage, regimen, or study length. All titles and abstracts located in the literature searches were assessed. Data were entered and analyzed with RevMan. A second author verified the data entered. For continuous data, we calculated the mean difference and 95% confidence interval (CI) for the mean change in weight between baseline and post-treatment measurements using a fixed-effect model. For categorical data, such as the proportion of women who gained or lost more than a specified amount of weight, the Peto odds ratio with 95% CI was calculated. We found 49 trials that met our inclusion criteria. The trials included 85 weight change comparisons for 52 distinct contraceptive pairs (or placebos). The four trials with a placebo or no intervention group did not find

  6. Weight Changes in General Practice.

    Science.gov (United States)

    Køster-Rasmussen, Rasmus

    2017-06-01

    This PhD thesis is about weight changes. What determines long-term weight changes in the adult general population? Is it possible that weight loss may not always be healthy? The present clinical guidelines for general practice advice most overweight persons and patients with type 2 diabetes to lose weight. Are the guidelines based on firm evidence?   METHODS: The back-bone of the thesis is constituted by three scientific articles based on three different population based cohort studies. Multivariable modeling and other epidemiological methods were used.   RESULTS: Article 1 examined weight changes in the general population in relation to smoking status, and proposed a graphical 'smoking cessation weight change model', demonstrating the importance of time, age and smoking status in relation to long-term weight changes. Article 2 suggested new methods to improve the processing of dietary data. It was demonstrated how median imputation for missing values and assumptions about standard portion sizes were inferior to stochastic methods conditioning on information about physiology of the individual. Article 3 evaluated the influence of prospectively planned intentional weight loss on long-term morbidity and mortality in patients with type 2 diabetes. Therapeutic intentional weight loss supervised by a medical doctor was not associated with reduced morbidity or mortality. In the general population the dietary intake of fructose and soft drinks sweetened with sugar was not associated with weight change over 9 years. Weight gain rates were large in young adults and incrementally smaller in middle aged adults. Subjects more than 60 years lost weight on average. Historical weight data suggest that the body weight increases throughout life to the age of 60-65years. A study with simulated data indicates that bias in baseline BMI may misleadingly have favored weight loss in earlier cohort studies of intentional weight loss and mortality.   DISCUSSION: The findings regarding

  7. Shellfish Feeding Experiments, Filter Weight and Tissue Weight

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Particulate matter removal by shellfish was quantified in several geographic locations, across several years. Data include filter and shellfish tissue weights.

  8. Rapid Weight Loss in Sports with Weight Classes.

    Science.gov (United States)

    Khodaee, Morteza; Olewinski, Lucianne; Shadgan, Babak; Kiningham, Robert R

    2015-01-01

    Weight-sensitive sports are popular among elite and nonelite athletes. Rapid weight loss (RWL) practice has been an essential part of many of these sports for many decades. Due to the limited epidemiological studies on the prevalence of RWL, its true prevalence is unknown. It is estimated that more than half of athletes in weight-class sports have practiced RWL during the competitive periods. As RWL can have significant physical, physiological, and psychological negative effects on athletes, its practice has been discouraged for many years. It seems that appropriate rule changes have had the biggest impact on the practice of RWL in sports like wrestling. An individualized and well-planned gradual and safe weight loss program under the supervision of a team of coaching staff, athletic trainers, sports nutritionists, and sports physicians is recommended.

  9. Correlates of Low Birth Weight

    Directory of Open Access Journals (Sweden)

    Ankur Barua MD, PhD

    2014-12-01

    Full Text Available Background. Low birth weight is the single most important factor that determines the chances of child survival. A recent annual estimation indicated that nearly 8 million infants are born with low birth weight in India. The infant mortality rate is about 20 times greater for all low birth weight babies. Methods. A matched case–control study was conducted on 130 low birth weight babies and 130 controls for 12 months (from August 1, 2007, to July 31, 2008 at the Central Referral Hospital, Tadong, East District of Sikkim, India. Data were analyzed using the Statistical Package for Social Sciences, version 10.0 for Windows. Chi-square test and multiple logistic regression were applied. A P value less than .05 was considered as significant. Results. In the first phase of this study, 711 newborn babies, borne by 680 mothers, were screened at the Central Referral Hospital of Sikkim during the 1-year study period, and the proportion of low birth weight babies was determined to be 130 (18.3%. Conclusion. Multiple logistic regression analysis, conducted in the second phase, revealed that low or middle socioeconomic status, maternal underweight, twin pregnancy, previous history of delivery of low birth weight babies, smoking and consumption of alcohol during pregnancy, and congenital anomalies had independent significant association with low birth weight in this study population.

  10. Weighted polynomial models and weighted sampling schemes for finite population

    OpenAIRE

    Chen, Sean X.

    1998-01-01

    This paper outlines a theoretical framework for finite population models with unequal sample probabilities, along with sampling schemes for drawing random samples from these models. We first present four exact weighted sampling schemes that can be used for any finite population model to satisfy such requirements as ordered/ unordered samples, with/without replacement, and fixed/nonfixed sample size. We then introduce a new class of finite population models called weighted po...

  11. Dietary Supplements for Weight Loss

    Science.gov (United States)

    ... 2 • WEIGHT-LOSS SUPPLEMENTS FACT SHEET FOR CONSUMERS Bitter orange Bitter orange contains synephrine (a stimulant), and is claimed to ... breakdown of fat, and decrease appetite. Products with bitter orange usually also contain caffeine and other ingredients. Bitter ...

  12. Healthy habits for weight loss

    Science.gov (United States)

    ... you or try to tempt you with old eating habits. Send progress reports. Tell your friends your goal weight and send them weekly updates of how you are doing. Use social media. Some mobile apps let you log everything you ...

  13. Breastfeeding reduces postpartum weight retention

    DEFF Research Database (Denmark)

    Baker, Jennifer Lyn; Gamborg, Michael; Heitmann, Berit L

    2008-01-01

    BACKGROUND: Weight gained during pregnancy and not lost postpartum may contribute to obesity in women of childbearing age. OBJECTIVE: We aimed to determine whether breastfeeding reduces postpartum weight retention (PPWR) in a population among which full breastfeeding is common and breastfeeding......) reduced PPWR at 6 and 18 mo after adjustment for maternal prepregnancy body mass index (BMI) and gestational weight gain (GWG). RESULTS: GWG was positively (P ... by that time in women with GWG values of approximately 12 kg, and that the possibility of major weight gain (>or=5 kg) could be reduced in all but the heaviest women. CONCLUSION: Breastfeeding was associated with lower PPWR in all categories of prepregnancy BMI. These results suggest that, when combined...

  14. Heritability of gestational weight gain

    DEFF Research Database (Denmark)

    Andersson, Elina Scheers; Silventoinen, Karri; Tynelius, Per

    2015-01-01

    Gestational weight gain (GWG) is a complex trait involving intrauterine environmental, maternal environmental, and genetic factors. However, the extent to which these factors contribute to the total variation in GWG is unclear. We therefore examined the genetic and environmental influences...

  15. Body Weight and Body Image

    OpenAIRE

    Olmsted, Marion P; McFarlane, Traci

    2004-01-01

    Abstract Health Issue Body weight is of physical and psychological importance to Canadian women; it is associated with health status, physical activity, body image, and self-esteem. Although the problems associated with overweight and obesity are indeed serious, there are also problems connected to being underweight. Weight prejudice and the dieting industry intensify body image concerns for Canadian women and can have a major negative impact on self-esteem. Key Findings Women have lower BMIs...

  16. Efficient Completion of Weighted Automata

    Directory of Open Access Journals (Sweden)

    Johannes Waldmann

    2016-09-01

    Full Text Available We consider directed graphs with edge labels from a semiring. We present an algorithm that allows efficient execution of queries for existence and weights of paths, and allows updates of the graph: adding nodes and edges, and changing weights of existing edges. We apply this method in the construction of matchbound certificates for automatically proving termination of string rewriting. We re-implement the decomposition/completion algorithm of Endrullis et al. (2006 in our framework, and achieve comparable performance.

  17. Weight Loss Strategies Utilized in a Men's Weight Loss Intervention.

    Science.gov (United States)

    Crane, Melissa M; Lutes, Lesley D; Sherwood, Nancy E; Ward, Dianne S; Tate, Deborah F

    2017-09-01

    Men are underrepresented in weight loss programs and little is currently known about the weight loss strategies men prefer. This study describes the weight loss strategies used by men during a men-only weight loss program. At baseline, 3 months, and 6 months, participants reported how frequently they used 45 weight loss strategies including strategies frequently recommended by the program (i.e., mentioned during every intervention contact; e.g., daily self-weighing), strategies occasionally recommended by the program (i.e., mentioned at least once during the program; e.g., reduce calories from beverages), and strategies not included in the program (e.g., increase daily steps). At baseline participants ( N = 107, 44.2 years, body mass index = 31.4 kg/m2, 76.6% White) reported regularly using 7.3 ± 6.6 ( M ± SD) strategies. The intervention group increased the number of strategies used to 19.1 ± 8.3 at 3 months and 17.1 ± 8.4 at 6 months with no changes in the waitlist group. The intervention group reported increased use of most of the strategies frequently recommended by the program (4 of 5), nearly half of the strategies occasionally recommended by the program (10 of 24), and one strategy not included in the program (of 16) at 6 months. The intervention effect at 6 months was significantly mediated by the number of strategies used at 3 months. This study adds to what is known about men's use of weight loss strategies prior to and during a formal weight loss program and will help future program developers create programs that are tailored to men.

  18. The Influence of Weight-Loss Expectations on Weight Loss and of Weight-Loss Satisfaction on Weight Maintenance in Severe Obesity.

    Science.gov (United States)

    Calugi, Simona; Marchesini, Giulio; El Ghoch, Marwan; Gavasso, Ilaria; Dalle Grave, Riccardo

    2017-01-01

    Conflicting evidence exists as to whether cognitive mechanisms contribute to weight loss and maintenance. To assess the influence of weight-loss expectations on weight loss, and of weight-loss satisfaction on weight maintenance, in individuals with severe obesity. A randomized controlled trial comparing two types of energy-restricted diets (high protein vs high carbohydrate) combined with weight-loss cognitive behavioral therapy, conducted over 51 weeks and divided into two phases: weight-loss phase (3 weeks of inpatient treatment and 24 weeks of outpatient treatment) and weight maintenance phase (24 weeks of outpatient treatment). Eighty-eight participants with severe obesity (mean age=46.7 years and mean body mass index=45.6), referred to an eating and weight disorders clinical service, were studied. Body weight was assessed at baseline, and after 3, 27 (end of weight-loss phase), and 51 weeks (end of weight maintenance phase). Weight loss expectations were assessed at the time of enrollment, and weight-loss satisfaction was assessed after 27 weeks. The relationship between weight-loss expectations and weight loss was assessed using a linear mixed model. The association between weight-loss satisfaction and final outcomes was tested by linear regression. The two groups had similar weight-loss expectations and satisfaction, and their results were therefore pooled. In general, the total amount of expected weight loss (in kilograms), but not the percentage of expected weight loss, predicted weight loss, and both satisfaction with weight loss and the amount of weight lost (in kilograms) were independent predictors of weight maintenance. Higher expected weight loss improves weight loss, and both the total amount of weight lost and satisfaction with weight loss are associated with weight-loss maintenance at 1-year follow-up. Copyright © 2017 Academy of Nutrition and Dietetics. Published by Elsevier Inc. All rights reserved.

  19. Financial incentives and weight control.

    Science.gov (United States)

    Jeffery, Robert W

    2012-11-01

    This paper reviews research studies evaluating the use of financial incentives to promote weight control conducted between 1972 and 2010. It provides an overview of behavioral theories pertaining to incentives and describes empirical studies evaluating specific aspects of incentives. Research on financial incentives and weight control has a history spanning more than 30 years. Early studies were guided by operant learning concepts from Psychology, while more recent studies have relied on economic theory. Both theoretical orientations argue that providing financial rewards for losing weight should motivate people to engage in behaviors that produce weight loss. Empirical research has strongly supported this idea. However, results vary widely due to differences in incentive size and schedule, as well as contextual factors. Thus, many important questions about the use of incentives have not yet been clearly answered. Weight-maintenance studies using financial incentives are particularly sparse, so that their long-term efficacy and thus, value in addressing the public health problem of obesity is unclear. Major obstacles to sustained applications of incentive in weight control are funding sources and acceptance by those who might benefit. Copyright © 2011 Elsevier Inc. All rights reserved.

  20. Three-dimensional isotropic fat-suppressed proton density-weighted MRI at 3 tesla using a T/R-coil can replace multiple plane two-dimensional sequences in knee imaging

    Energy Technology Data Exchange (ETDEWEB)

    Homsi, R.; Luetkens, J.A. [Bonn Univ. (Germany). Dept. of Radiology; Gieseke, J. [Philips Healthcare, Hamburg (Germany); and others

    2016-10-15

    To evaluate whether a 3D proton density-weighted fat-suppressed sequence (PDwFS) of the knee is able to replace multiplanar 2D-PDwFS. 52 patients (26 men, mean age: 41.9±14.5 years) underwent magnetic resonance imaging (MRI) of the knee at 3.0 Tesla using a T/R-coil. The imaging protocol included 3 planes of 2D-PDwFS (acquisition time (AT): 6:40 min; voxel sizes: 0.40-0.63 x 0.44-0.89 x 3 mm{sup 3}) and a 3D-PDwFS (AT: 6:31 min; voxel size: 0.63 x 0.68 x 0.63 mm{sup 3}). Homogeneity of fat suppression (HFS), artifacts, and image sharpness (IS) were evaluated on a 5-point scale (5[excellent] - 1[non-diagnostic]). The sum served as a measure for the overall image quality (OIQ). Contrast ratios (CR) compared to popliteal muscle were calculated for the meniscus (MEN), anterior (ACL) and posterior cruciate ligaments (PCL). In 13 patients who underwent arthroscopic knee surgery, two radiologists evaluated the presence of meniscal, ligamental and cartilage lesions to estimate the sensitivity and specificity of lesion detection. The CR was higher in the ACL, PCL and MEN in 3D- PDwFS compared to 2D-PDwFS (p<0.01 for ACL and PCL; p=0.07 for MEN). Compared to 2D images, the OIQ was rated higher in 3D-PDwFS images (p<0.01) due to fewer artifacts and HFS despite the lower IS (p<0.01). The sensitivity and specificity of lesion detection in 3D- and 2D-PDwFS were similar. Compared to standard multiplanar 2D-PDwFS knee imaging, isotropic high spatial resolution 3D-PDwFS of the knee at 3.0T can be acquired with high image quality in a reasonable scan time. Multiplanar reformations in arbitrary planes may serve as an additional benefit of 3D-PDwFS.

  1. Preventing Excessive Gestational Weight Gain and Postpartum Weight Retention.

    LENUS (Irish Health Repository)

    O’Dwyer, V

    2017-10-01

    regnancy and the postpartum period are unique opportunities to promote healthy lifestyle choices including a healthy diet and regular exercise. This is especially important for those who are overweight or obese. Women are weighed at their first antenatal visit and body mass index (BMI) calculated, but not all hospitals routinely weigh women throughout pregnancy. A qualitative Dublin study examined experiences of routine weighing during antenatal care. This study found that women expected to be weighed during pregnancy and postpartum. The benefits of this included providing reassurance and minimising postpartum weight retention. Furthermore, women were eager to receive more information about healthy lifestyle interventions and gestational weight gain (GWG) from healthcare professionals

  2. Personality disorders and body weight.

    Science.gov (United States)

    Maclean, Johanna Catherine; Xu, Haiyong; French, Michael T; Ettner, Susan L

    2014-01-01

    We examine the impact of Axis II personality disorders (PDs) on body weight. PDs are psychiatric conditions that develop early in life from a mixture of genetics and environment, are persistent, and lead to substantial dysfunction for the affected individual. The defining characteristics of PDs conceptually link them with body weight, but the direction of the relationship likely varies across PD type. To investigate these links, we analyze data from Wave II of the National Epidemiological Survey of Alcohol and Related Conditions. We measure body weight with the body mass index (BMI) and a dichotomous indicator for obesity (BMI≥30). We find that women with PDs have significantly higher BMI and are more likely to be obese than otherwise similar women. We find few statistically significant or economically meaningful effects for men. Paranoid, schizotypal, and avoidant PDs demonstrate the strongest adverse impacts on women's body weight while dependent PD may be protective against elevated body weight among men. Findings from unconditional quantile regressions demonstrate a positive gradient between PDs and BMI in that the effects are greater for higher BMI respondents. Copyright © 2013 Elsevier B.V. All rights reserved.

  3. Cascaded failures in weighted networks

    Science.gov (United States)

    Mirzasoleiman, Baharan; Babaei, Mahmoudreza; Jalili, Mahdi; Safari, Mohammadali

    2011-10-01

    Many technological networks can experience random and/or systematic failures in their components. More destructive situations can happen if the components have limited capacity, where the failure in one of them might lead to a cascade of failures in other components, and consequently break down the structure of the network. In this paper, the tolerance of cascaded failures was investigated in weighted networks. Three weighting strategies were considered including the betweenness centrality of the edges, the product of the degrees of the end nodes, and the product of their betweenness centralities. Then, the effect of the cascaded attack was investigated by considering the local weighted flow redistribution rule. The capacity of the edges was considered to be proportional to their initial weight distribution. The size of the survived part of the attacked network was determined in model networks as well as in a number of real-world networks including the power grid, the internet in the level of autonomous system, the railway network of Europe, and the United States airports network. We found that the networks in which the weight of each edge is the multiplication of the betweenness centrality of the end nodes had the best robustness against cascaded failures. In other words, the case where the load of the links is considered to be the product of the betweenness centrality of the end nodes is favored for the robustness of the network against cascaded failures.

  4. Weighted Watson-Crick automata

    Energy Technology Data Exchange (ETDEWEB)

    Tamrin, Mohd Izzuddin Mohd [Department of Information System, Kulliyyah of Information and Communication Technology, International Islamic University Malaysia, 50728 Gombak, Selangor (Malaysia); Turaev, Sherzod; Sembok, Tengku Mohd Tengku [Department of Computer Science, Kulliyyah of Information and Communication Technology, International Islamic University Malaysia, 50728 Gombak, Selangor (Malaysia)

    2014-07-10

    There are tremendous works in biotechnology especially in area of DNA molecules. The computer society is attempting to develop smaller computing devices through computational models which are based on the operations performed on the DNA molecules. A Watson-Crick automaton, a theoretical model for DNA based computation, has two reading heads, and works on double-stranded sequences of the input related by a complementarity relation similar with the Watson-Crick complementarity of DNA nucleotides. Over the time, several variants of Watson-Crick automata have been introduced and investigated. However, they cannot be used as suitable DNA based computational models for molecular stochastic processes and fuzzy processes that are related to important practical problems such as molecular parsing, gene disease detection, and food authentication. In this paper we define new variants of Watson-Crick automata, called weighted Watson-Crick automata, developing theoretical models for molecular stochastic and fuzzy processes. We define weighted Watson-Crick automata adapting weight restriction mechanisms associated with formal grammars and automata. We also study the generative capacities of weighted Watson-Crick automata, including probabilistic and fuzzy variants. We show that weighted variants of Watson-Crick automata increase their generative power.

  5. Executive function in weight loss and weight loss maintenance: a conceptual review and novel neuropsychological model of weight control.

    Science.gov (United States)

    Gettens, Katelyn M; Gorin, Amy A

    2017-10-01

    Weight loss maintenance is a complex, multifaceted process that presents a significant challenge for most individuals who lose weight. A growing body of literature indicates a strong relationship between cognitive dysfunction and excessive body weight, and suggests that a subset of high-order cognitive processes known as executive functions (EF) likely play an important role in weight management. Recent reviews cover neuropsychological correlates of weight status yet fail to address the role of executive function in the central dilemma of successful weight loss maintenance. In this paper, we provide an overview of the existing literature examining executive functions as they relate to weight status and initial weight loss. Further, we propose a novel conceptual model of the relationships between EF, initial weight loss, and weight loss maintenance, mapping specific executive functions onto strategies known to be associated with both phases of the weight control process. Implications for the development of more efficacious weight loss maintenance interventions are discussed.

  6. FTO genotype and weight loss

    DEFF Research Database (Denmark)

    Livingstone, Katherine M; Celis-Morales, Carlos; Papandonatos, George D

    2016-01-01

    : Ovid Medline, Scopus, Embase, and Cochrane from inception to November 2015. ELIGIBILITY CRITERIA FOR STUDY SELECTION: Randomised controlled trials in overweight or obese adults reporting reduction in body mass index, body weight, or waist circumference by FTO genotype (rs9939609 or a proxy) after...... well to dietary, physical activity, or drug based weight loss interventions and thus genetic predisposition to obesity associated with the FTO minor allele can be at least partly counteracted through such interventions. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42015015969.......OBJECTIVE: To assess the effect of the FTO genotype on weight loss after dietary, physical activity, or drug based interventions in randomised controlled trials. DESIGN: Systematic review and random effects meta-analysis of individual participant data from randomised controlled trials. DATA SOURCES...

  7. Average weighted receiving time in recursive weighted Koch networks

    Indian Academy of Sciences (India)

    Motivated by the empirical observation in airport networks and metabolic networks, we introduce the model of the recursive weighted Koch networks created by the recursive division method. As a fundamental dynamical process, random walks have received considerable interest in the scientific community. Then, we study ...

  8. Birth weight recovery among very low birth weight infants surviving ...

    African Journals Online (AJOL)

    A multiple linear regression showed a negative association between ZSW at discharge and number of days nil per os without parenteral nutrition (PN). Antenatal steroids were associated with poor GV. There were no factors associated with regaining birth weight after 21 days on multiple logistic regression. Conclusion.

  9. Spleen Weight, Liver Weight And Levels Of Circulating Immune ...

    African Journals Online (AJOL)

    Three groups of mice viz: well fed mice, vitamin deficient mice and vitamin deficient Plasmodium berghei infected mice were studied. In these groups of mice, the weights of the liver and spleen were determined using a weighing balance and the levels of circulating immune complexes (CICS) measured ...

  10. Maternal Gestational and Postdelivery Weight Gain and Child Weight

    NARCIS (Netherlands)

    van Rossem, Lenie; Wijga, Alet H; Gehring, Ulrike|info:eu-repo/dai/nl/304831344; Koppelman, Gerard H; Smit, Henriette A

    2015-01-01

    BACKGROUND: Maternal gestational weight gain (GWG) is a risk factor for the development of overweight in her child. It is unknown whether GWG programs the child's health or whether GWG indicates a shared familial lifestyle during childhood. To disentangle these influences, we studied the association

  11. Maternal gestational and postdelivery weight gain and child weight

    NARCIS (Netherlands)

    Van Rossem, Lenie; Wijga, Alet H.; Gehring, Ulrike; Koppelman, Gerard H.; Smit, Henriette A.

    2015-01-01

    BACKGROUND: Maternal gestational weight gain (GWG) is a risk factor for the development of overweight in her child. It is unknown whether GWG programs the child's health or whether GWG indicates a shared familial lifestyle during childhood. To disentangle these influences, we studied the association

  12. Parametric Verification of Weighted Systems

    DEFF Research Database (Denmark)

    Christoffersen, Peter; Hansen, Mikkel; Mariegaard, Anders

    2015-01-01

    This paper addresses the problem of parametric model checking for weighted transition systems. We consider transition systems labelled with linear equations over a set of parameters and we use them to provide semantics for a parametric version of weighted CTL where the until and next operators...... are themselves indexed with linear equations. The parameters change the model-checking problem into a problem of computing a linear system of inequalities that characterizes the parameters that guarantee the satisfiability. To address this problem, we use parametric dependency graphs (PDGs) and we propose...

  13. Polynomial weights and code constructions.

    Science.gov (United States)

    Massey, J. L.; Costello, D. J., Jr.; Justesen, J.

    1973-01-01

    Study of certain polynomials with the 'weight-retaining' property that any linear combination of these polynomials with coefficients in a general finite field has Hamming weight at least as great as that of the minimum-degree polynomial included. This fundamental property is used in applications to Reed-Muller codes, a new class of 'repeated-root' binary cyclic codes, two new classes of binary convolutional codes derived from binary cyclic codes, and two new classes of binary convolutional codes derived from Reed-Solomon codes.

  14. Weighted Means through the Looking Glass

    Science.gov (United States)

    Falk, Ruma; Lann, Avital Lavie

    2013-01-01

    Each weighted mean of two values has a counterpart, equidistant from the arithmetic mean, obtained by exchanging roles between the weights or by inversing each weight. These elementary relations are apt for introductory courses.

  15. Psychosocial Consequences of Weight Cycling.

    Science.gov (United States)

    Bartlett, Susan J.; And Others

    1996-01-01

    Participants were 130 obese women who reported undertaking a mean lifetime total of 4.7 major diets on which they had lost a mean of 45.9 kilograms. Participants with a severe history of weight cycling had a significantly younger age of onset of obesity than mild cyclers and reported initiating dieting at a significantly younger age and lower…

  16. Risk Attitudes and Decision Weights

    NARCIS (Netherlands)

    A. Tversky (Amos); P.P. Wakker (Peter)

    1995-01-01

    textabstractTo accommodate the observed pattern of risk-aversion and risk-seeking, as well as common violations of expected utility (e.g., the certainty effect), we introduce and characterize a weighting function according to which an event has greater impact when it turns impossibility into

  17. Training in Conservation of Weight

    Science.gov (United States)

    Overbeck, Carla; Schwartz, Marian

    1970-01-01

    Reinforcement training was shown to facilitate acquisition of conservation of weight, while active participation was no more effective than passive observation. This report is based on a thesis submitted in partial fulfillment of requirements for the M.S. degree by the first author under the supervision of the second author. (MH)

  18. Abandoning weight-loss programmes

    African Journals Online (AJOL)

    the weight-loss programme. The facilitator of the discu.ssion groups, a clinical psychologist, asked only non-directive ques- tions and ensured participation of all members in the group. For every 4 panicipants a silent and non-panicipant observer recorded contributions. Group members formed a circle and silent observers ...

  19. Prediction of low birth weight

    DEFF Research Database (Denmark)

    Sinding, Marianne; Peters, David A; Frøkjær, Jens B

    2017-01-01

    operating characteristic curves demonstrated a significantly higher performance of T2* (AUC of 0.92; 95% CI, 0.85-0.98) than UtA PI (AUC of 0.74; 95% CI, 0.60-0.89) in the prediction of low birth weight (p = 0.010). Placental pathological findings were closely related to the T2* values. CONCLUSIONS...... placental function. Therefore, we aimed to evaluate the performance of placental T2* in the prediction of low birth weight using the uterine artery (UtA) pulsatility index (PI) as gold standard. METHODS: This was a prospective observational study of 100 singleton pregnancies included at 20-40 weeks......' gestation. Placental T2* was obtained using a gradient recalled multi-echo MRI sequence and UtA PI was measured using Doppler ultrasound. Placental pathological examination was performed in 57 of the pregnancies. Low birth weight was defined by a Z-score ≤ -2.0. RESULTS: The incidence of low birth weight...

  20. Spontaneous tetraplegia during weight training

    Science.gov (United States)

    Clewer, G; Carmont, M; Jaffray, D

    2006-01-01

    A case of tetraplegia due to weight training is presented. Emergency surgery revealed a huge C5/6 disc sequestration trapped within the canal by the posterior longitudinal ligament. The disc was removed and C5–C7 were fused using an iliac crest tricortical graft and stabilised. The patient made a good recovery and returned to sporting activity. PMID:16980532

  1. Weight and Diabetes (For Parents)

    Science.gov (United States)

    ... February 2018 More on this topic for: Parents Kids Teens Diabetes Center Can Diabetes Be Prevented? Your Child's Diabetes Health Care Team Type 1 Diabetes: What Is It? Body Mass Index (BMI) ... Plans: What Kids With Diabetes Need to Know Diabetes Center Weight ...

  2. Understanding weight gain at menopause.

    Science.gov (United States)

    Davis, S R; Castelo-Branco, C; Chedraui, P; Lumsden, M A; Nappi, R E; Shah, D; Villaseca, P

    2012-10-01

    The aim of this review was to summarize the literature regarding the impact of the menopause transition on body weight and body composition. We conducted a search of the literature using Medline (Ovid, 1946-present) and PubMed (1966-2012) for English-language studies that included the following search terms: 'menopause', 'midlife', 'hormone therapy' or 'estrogen' combined with 'obesity', 'body weight' or 'body composition'. Whereas weight gain per se cannot be attributed to the menopause transition, the change in the hormonal milieu at menopause is associated with an increase in total body fat and an increase in abdominal fat. Weight excess at midlife is not only associated with a heightened risk of cardiovascular and metabolic disease, but also impacts adversely on health-related quality of life and sexual function. Animal and human studies indicate that this tendency towards central abdominal fat accumulation is ameliorated by estrogen therapy. Studies mostly indicate a reduction in overall fat mass with estrogen and estrogen-progestin therapy, improved insulin sensitivity and a lower rate of development of type 2 diabetes. The hormonal changes across the perimenopause substantially contribute to increased abdominal obesity which leads to additional physical and psychological morbidity. There is strong evidence that estrogen therapy may partly prevent this menopause-related change in body composition and the associated metabolic sequelae. However, further studies are required to identify the women most likely to gain metabolic benefit from menopausal hormone therapy in order to develop evidence-based clinical recommendations.

  3. FTO genotype and weight loss

    DEFF Research Database (Denmark)

    Livingstone, Katherine M; Celis-Morales, Carlos; Papandonatos, George D

    2016-01-01

    OBJECTIVE: To assess the effect of the FTO genotype on weight loss after dietary, physical activity, or drug based interventions in randomised controlled trials. DESIGN: Systematic review and random effects meta-analysis of individual participant data from randomised controlled trials. DATA SOURC...

  4. Generating Constant Weight Binary Codes

    Science.gov (United States)

    Knight, D.G.

    2008-01-01

    The determination of bounds for A(n, d, w), the maximum possible number of binary vectors of length n, weight w, and pairwise Hamming distance no less than d, is a classic problem in coding theory. Such sets of vectors have many applications. A description is given of how the problem can be used in a first-year undergraduate computational…

  5. Effect of Smoking Cessation on Gestational and Postpartum Weight Gain and Neonatal Birth Weight

    DEFF Research Database (Denmark)

    Rode, Line; Kjærgaard, Hanne; Damm, Peter

    2013-01-01

    To examine the association among smoking cessation, gestational and postpartum weight gain, and neonatal birth weight.......To examine the association among smoking cessation, gestational and postpartum weight gain, and neonatal birth weight....

  6. Thermodynamics of weight loss diets

    Directory of Open Access Journals (Sweden)

    Fine Eugene J

    2004-12-01

    Full Text Available Abstract Background It is commonly held that "a calorie is a calorie", i.e. that diets of equal caloric content will result in identical weight change independent of macronutrient composition, and appeal is frequently made to the laws of thermodynamics. We have previously shown that thermodynamics does not support such a view and that diets of different macronutrient content may be expected to induce different changes in body mass. Low carbohydrate diets in particular have claimed a "metabolic advantage" meaning more weight loss than in isocaloric diets of higher carbohydrate content. In this review, for pedagogic clarity, we reframe the theoretical discussion to directly link thermodynamic inefficiency to weight change. The problem in outline: Is metabolic advantage theoretically possible? If so, what biochemical mechanisms might plausibly explain it? Finally, what experimental evidence exists to determine whether it does or does not occur? Results Reduced thermodynamic efficiency will result in increased weight loss. The laws of thermodynamics are silent on the existence of variable thermodynamic efficiency in metabolic processes. Therefore such variability is permitted and can be related to differences in weight lost. The existence of variable efficiency and metabolic advantage is therefore an empiric question rather than a theoretical one, confirmed by many experimental isocaloric studies, pending a properly performed meta-analysis. Mechanisms are as yet unknown, but plausible mechanisms at the metabolic level are proposed. Conclusions Variable thermodynamic efficiency due to dietary manipulation is permitted by physical laws, is supported by much experimental data, and may be reasonably explained by plausible mechanisms.

  7. T1 weighted brain images at 7 Tesla unbiased for Proton Density, T2* contrast and RF coil receive B1 sensitivity with simultaneous vessel visualization.

    Science.gov (United States)

    Van de Moortele, Pierre-François; Auerbach, Edwards J; Olman, Cheryl; Yacoub, Essa; Uğurbil, Kâmil; Moeller, Steen

    2009-06-01

    , we introduce a simple technique to reduce residual signal intensity variations induced by transmit B(1) heterogeneity. Because this approach requires two 3D images, one divided with the other, head motion could create serious problems, especially at high spatial resolution. To alleviate such inter-scan motion problems, we developed a new sequence where the two contrast acquisitions are interleaved within a single scan. This interleaved approach however comes with greater risk of intra-scan motion issues because of a longer single scan time. Users can choose between these two trade offs depending on specific protocols and patient populations. We believe that the simplicity and the robustness of this double contrast based approach to address intensity field bias at high field and improve T(1) contrast specificity, together with the capability of simultaneously obtaining angiography maps, advantageously counter balance the potential drawbacks of the technique, mainly a longer acquisition time and a moderate reduction in signal to noise ratio.

  8. T1 weighted Brain Images at 7 Tesla Unbiased for Proton Density, T2* contrast and RF Coil Receive B1 Sensitivity with Simultaneous Vessel Visualization

    Science.gov (United States)

    Van de Moortele, Pierre-François; Auerbach, Edwards J.; Olman, Cheryl; Yacoub, Essa; Uğurbil, Kâmil; Moeller, Steen

    2009-01-01

    to reduce residual signal intensity variations induced by Transmit B1 heterogeneity. Because this approach requires two 3D images, one divided with the other, head motion could create serious problems, especially at high spatial resolution. To alleviate such inter-scan motion problems, we developed a new sequence where the two contrast acquisitions are interleaved within a single scan. This interleaved approach however comes with greater risk of intra-scan motion issues because of a longer single scan time. Users can choose between these two trade offs depending on specific protocols and patient populations. We believe that the simplicity and the robustness of this double contrast based approach to address intensity field bias at high field and improve T1 contrast specificity, together with the capability of simultaneously obtaining angiography maps, advantageously counter balance the potential drawbacks of the technique, mainly a longer acquisition time and a moderate reduction in signal to noise ratio. PMID:19233292

  9. Effect of Season, Birth Weight and Weaning Weight on the onset of ...

    African Journals Online (AJOL)

    A study was conducted to determine the effect of season, birth weight and weaning weight on the onset of puberty of 31 crossbred (Friesian & Bunaji) calves born from 1999 to 2005. The parameters considered were season of birth, birth weight, weaning weight body weight from 12-27 month of age and age and weight at ...

  10. BIRTH WEIGHT : A COMMUNITY PERSPECTIVE

    Directory of Open Access Journals (Sweden)

    J P SRIVASTAVA

    2003-06-01

    Full Text Available India has a dubious distinction of belonging to the top bracket of countries with a very high under-5 Mortality Rate (U5MR of above 96/1000 live births. The U5MR considered the single most significant basic indicator of health status of a community, is proportional to the Infant Mortality Rate (IMR which in turn is contributed to directly and indirectly by the incidence of low Birth Weight (LB W.About 25 million LB W are born each year consisting 17% of all live births,nearly 95% of them in developing countries. About 26% of newborns are LBW in India, and indeed over 16% in those countries with very high U5MR.Both preterm and small-for-dates almost equally make up this category of vulnerable infants predisposed to asphyxia, feeding problems, anemia and growth failure.Considering the close relationship of birth weight with perinatal and infant morbidity as well as mortality, it is crucial to identify the liigh risk groups of low birth weight babies as early as possible.Unfortunately, in a community where 80% of newborns never get to have their weight measured, this itself is a tall order. In our society, the cry of the newborn is greeted with anxious queries about the sex of the baby and not his well­being and potential for healthy survival. The basic concept of the importance of birth weight is missing even among educated families. Indeed, it is as if the weighing machine has no place in the requirements at childbirth. In the absence of this basic facility, field workers and TBAs must report to other means to identify babies at risk. Mid-arm circumference, thigh circumference, foot length, and skin-fold thickness etc. are measurements that have been correlated satisfactorily with the baby’s weight. Simple tools like coloured strips have been developed and these show promise of applicability in field situation for identification of LB W by TBAs for early referral.

  11. Weight in Parkinson's Disease: Phenotypical Significance.

    Science.gov (United States)

    Sharma, Jagdish C; Lewis, Anna

    2017-01-01

    Body weight in Parkinson's disease (PD) is a significant nonmotor feature. Weight homeostasis is a complex physiological process and gets deranged in PD patients leading to changes in weight. While both the low and high body weight have been reported as risk factors for PD, the majority of PD patients have a lower weight and a subset of patients lose weight during the course of the disease, while a small proportion gain weight. A number of clinical parameters such as older age, impaired cognition, severity of disease, and an imbalance of food intake determined by satiety and hunger hormones have been reported to be associated with but not the cause of weight change. Low body weight and weight loss have a negative impact on disease severity, dyskinesia quality of life, and mortality indicative of disease progression. An early assessment of olfactory impairment seems to identify patients at risk of weight loss, the patients with more severe olfactory loss-anosmic group, lose weight as compared to the patients with some preservation of olfaction, the hyposmic group. Higher levodopa dose per kilogram body weight increases the risk of dyskinesia, higher body weight seems to be protective against this complication. The identification of PD patients according to the nonmotor phenotype of "Park-olfaction-weight-phenotype" and the "olfaction-weight-dyskinesia" triad should help to develop strategies to prevent weight reduction and improve general health and complications of PD patients. The phenotype seems to reflect a differential prodromal pathology and influence clinical disease. Higher body weight patients would benefit from life style changes to achieve a healthy profile. Weight monitoring and weight orientated approach to management of PD patients should help to improve their outcome. Body weight change might be a surrogate to disease progression and may be used to investigate neuroprotection strategies. © 2017 Elsevier Inc. All rights reserved.

  12. Psychological workload and body weight

    DEFF Research Database (Denmark)

    Overgaard, Dorthe; Gyntelberg, F; Heitmann, B L

    2004-01-01

    BACKGROUND: According to Karasek's Demand/Control Model, workload can be conceptualized as job strain, a combination of psychological job demands and control in the job. High job strain may result from high job demands combined with low job control. Aim To give an overview of the literature...... on the association between obesity and psychological workload. METHOD: We carried out a review of the associations between psychological workload and body weight in men and women. In total, 10 cross-sectional studies were identified. RESULTS: The review showed little evidence of a general association between...... psychological workload and body mass index. Only weak positive associations were found, and only between elements of psychological workload and overall body weight. For body fat distribution, two out of three studies showed a positive association in men, but the associations became insignificant after...

  13. Toxicity of weight loss agents.

    Science.gov (United States)

    Yen, May; Ewald, Michele Burns

    2012-06-01

    With the rise of the obesity epidemic in the United States over the last several decades and the medical complications seen with it, weight loss and dieting have become a national public health concern. Because of their increased use and availability through internet sales, several different dieting agents were reviewed for potential toxicity. These included: syrup of ipecac, cathartics, human chorionic gonadotropin hormone, 2,4 Dinitrophenol, guar gum, phenylpropanolamine, ma huang/ ephedra, caffeine, clenbuterol, fenfluramine, sibutramine, thyroid hormone, orlistat and cannabinoid antagonists. With the internet making even banned products readily accessible, healthcare providers need to be aware of the potential toxicities of a wide range of weight loss agents. Our review covered topics we thought to be most historically significant as well as pertinent to the practice of medical toxicology today.

  14. Algorithm project weight calculation aircraft

    Directory of Open Access Journals (Sweden)

    Г. В. Абрамова

    2013-07-01

    Full Text Available The paper describes the process of a complex technical object design on the example of the aircraft, using information technology such as CAD/CAM/CAE-systems, presents the basic models of aircraft which are developed in the process of designing and reflect the different aspects of its structure and function. The idea of control parametric model at complex technical object design is entered, which is a set of initial data for the development of design stations and enables the optimal complex technical object control at all stages of design using modern computer technology. The paper discloses a process of weight design, which is associated with all stages of development aircraft and its production. Usage of a scheduling algorithm that allows to organize weight calculations are carried out at various stages of planning and weighing options to optimize the use of available database of formulas and methods of calculation

  15. Weight stability in Parkinson's disease.

    Science.gov (United States)

    Lindskov, Susanne; Sjöberg, Klas; Hagell, Peter; Westergren, Albert

    2016-01-01

    Parkinson's disease (PD) has traditionally been associated with weight loss. However, recent studies have not found any evidence of underweight in PD. Nevertheless, few studies have addressed nutritional status changes over time in relation to other clinical PD features. Here, we explore changes in nutritional status and motor and non-motor PD features (including dopaminergic drug therapy) in PD patients after 1 year. Motor and non-motor PD features, dopaminergic drug therapy, under-nutrition and malnutrition risk, and anthropometric measures (BMI, handgrip strength, triceps skin-fold, mid-arm circumference, and mid-upper arm muscle circumference) were assessed at baseline and 1 year later among 65 people with PD. Disability, PD motor symptoms, dysautonomia, and dopaminergic drug therapy increased. Underweight was uncommon both at baseline (n = 3) and follow-up (n = 2); malnutrition risk was common but stable (88 and 92%), whereas triceps skin-fold increased (P = 0.030); mid-upper arm muscle circumference decreased (P = 0.002); and the proportion of people with low handgrip strength (P = 0.012) increased. Correlations between nutritional variables and motor and non-motor PD features were absent to modest. Multiple linear regression analysis showed that baseline pupillomotor functioning was associated with decreased weight and BMI, and sleep with increased weight and BMI. In addition, increases in anxiety were associated with decreased weight, BMI, and triceps skin-fold. During the PD course, there seems to be redistribution in body composition from muscle to fat. Studies are needed to identify possible explanations for the findings. This implies that malnutrition should be regularly screened to identify those at risk of developing reduced muscle mass and increased morbidity.

  16. Uniform-Dead-Weight Brazing

    Science.gov (United States)

    Gaw, William D.

    1991-01-01

    Method of deadweight loading for vacuum-furnace brazing improves quality of joint, increases yield, and reduces costs. In improved method, plates weighted with heavy stainless-steel blocks. Blocks act independently and are immune to distortion. Besides being uniformly distributed, force applied to plates larger and repeatable from one brazing operation to next. Larger blocks used on edges of plates, where more thermal mass needed to reduce differences between temperatures of interior and edge as temperature of furnace varied.

  17. Weight Maintenance: Determinants of Success

    Science.gov (United States)

    2005-12-15

    Davis Highway, Suite 1204, Arlington, VA 22202-4302, and to the Office of Management and Budget, Paperwork Reduction Project 10704-0188), Washington, DC...Complications of pregnancy such as gestational diabetes, preeclampsia and operative delivery complications (i.e., c-sections) In addition to overall poor...Weight Management clinic in Boca Raton, Florida, suggests "This may be the first generation of children that may have a shorter life span than their

  18. Generalized Selection Weighted Vector Filters

    Directory of Open Access Journals (Sweden)

    Rastislav Lukac

    2004-09-01

    Full Text Available This paper introduces a class of nonlinear multichannel filters capable of removing impulsive noise in color images. The here-proposed generalized selection weighted vector filter class constitutes a powerful filtering framework for multichannel signal processing. Previously defined multichannel filters such as vector median filter, basic vector directional filter, directional-distance filter, weighted vector median filters, and weighted vector directional filters are treated from a global viewpoint using the proposed framework. Robust order-statistic concepts and increased degree of freedom in filter design make the proposed method attractive for a variety of applications. Introduced multichannel sigmoidal adaptation of the filter parameters and its modifications allow to accommodate the filter parameters to varying signal and noise statistics. Simulation studies reported in this paper indicate that the proposed filter class is computationally attractive, yields excellent performance, and is able to preserve fine details and color information while efficiently suppressing impulsive noise. This paper is an extended version of the paper by Lukac et al. presented at the 2003 IEEE-EURASIP Workshop on Nonlinear Signal and Image Processing (NSIP '03 in Grado, Italy.

  19. Weight changes in adult twins.

    Science.gov (United States)

    Fabsitz, R; Feinleib, M; Hrubec, Z

    1980-01-01

    Longitudinal study of 514 pairs of US white male twin veterans was made possible by compiling data from military records, mailed questionnaires, and physical examinations. Height and weight were used to calculate the Quetelet index for twins at different ages covering induction into the Armed Forces (generally 17-24 years), 25 years, 40-50 years at questionnaire response, and 42-56 at physical examination. Cross-sectional analyses of Quetelet Index at these 4 points in time showed consistent evidence of significant genetic variance. Additional twin analyses of change in Quetelet Index both from induction and from age 25 to approximately age 48 were done. Both analyses showed significant genetic variance for change in Quetelet Index during this time span of 25 or more years for most subjects. Heritability estimates were 0.6 for change in Quetelet Index from induction (mean age 20) to examination (mean age 48) and 0.7 for change in Quetelet Index from age 25 to examination. While studies of younger twins have shown significant genetic influence on growth (height and weight), this study of adults demonstrates significant genetic influence on change in weight even after maturation.

  20. National neonatal weight policy survey.

    LENUS (Irish Health Repository)

    Walsh, B

    2012-02-01

    This survey was conducted to review the current practice regarding frequency of weight measurement in neonatal units in the Republic of Ireland, and whether these practices are in keeping with best practice as described in the literature. There was an 88.5% (23 of 26) response rate to this survey. 6 (26%) units had a written policy, and 16 (70%) had an unwritten agreed practice. In the Vermont Oxford Network\\'s potentially better practices daily weight measurements on newborn infants are recommended until the infant is stable and growing and then alternate day measurements The most common practices in this survey were to weigh infants on alternate days, this occurred in 9 (39%) units, and twice weekly in 6 (26%). Less than 31% of units had a separate policy for those less than 30 weeks, on assisted ventilation, or transitioning to enteral feeds. Most weigh infants on alternate days, and plot weights weekly, which is in keeping with best practice. Few units have separate policies for specific subgroups as is recommended in the limited literature. Consensus guidelines should be developed and promoted nationally.

  1. National neonatal weight policy survey.

    LENUS (Irish Health Repository)

    Walsh, B

    2009-06-01

    This survey was conducted to review the current practice regarding frequency of weight measurement in neonatal units in the Republic of Ireland, and whether these practices are in keeping with best practice as described in the literature. There was an 88.5% (23 of 26) response rate to this survey. 6 (26%) units had a written policy, and 16 (70%) had an unwritten agreed practice. In the Vermont Oxford Network\\'s potentially better practices daily weight measurements on newborn infants are recommended until the infant is stable and growing and then alternate day measurements The most common practices in this survey were to weigh infants on alternate days, this occurred in 9 (39%) units, and twice weekly in 6 (26%). Less than 31% of units had a separate policy for those less than 30 weeks, on assisted ventilation, or transitioning to enteral feeds. Most weigh infants on alternate days, and plot weights weekly, which is in keeping with best practice. Few units have separate policies for specific subgroups as is recommended in the limited literature. Consensus guidelines should be developed and promoted nationally.

  2. Epidemic spread on weighted networks.

    Directory of Open Access Journals (Sweden)

    Christel Kamp

    Full Text Available The contact structure between hosts shapes disease spread. Most network-based models used in epidemiology tend to ignore heterogeneity in the weighting of contacts between two individuals. However, this assumption is known to be at odds with the data for many networks (e.g. sexual contact networks and to have a critical influence on epidemics' behavior. One of the reasons why models usually ignore heterogeneity in transmission is that we currently lack tools to analyze weighted networks, such that most studies rely on numerical simulations. Here, we present a novel framework to estimate key epidemiological variables, such as the rate of early epidemic expansion (r0 and the basic reproductive ratio (R0, from joint probability distributions of number of partners (contacts and number of interaction events through which contacts are weighted. These distributions are much easier to infer than the exact shape of the network, which makes the approach widely applicable. The framework also allows for a derivation of the full time course of epidemic prevalence and contact behaviour, which we validate with numerical simulations on networks. Overall, incorporating more realistic contact networks into epidemiological models can improve our understanding of the emergence and spread of infectious diseases.

  3. Gastric stimulation for weight loss

    Science.gov (United States)

    Mizrahi, Meir; Ben Ya'acov, Ami; Ilan, Yaron

    2012-01-01

    The prevalence of obesity is growing to epidemic proportions, and there is clearly a need for minimally invasive therapies with few adverse effects that allow for sustained weight loss. Behavior and lifestyle therapy are safe treatments for obesity in the short term, but the durability of the weight loss is limited. Although promising obesity drugs are in development, the currently available drugs lack efficacy or have unacceptable side effects. Surgery leads to long-term weight loss, but it is associated with morbidity and mortality. Gastric electrical stimulation (GES) has received increasing attention as a potential tool for treating obesity and gastrointestinal dysmotility disorders. GES is a promising, minimally invasive, safe, and effective method for treating obesity. External gastric pacing is aimed at alteration of the motility of the gastrointestinal tract in a way that will alter absorption due to alteration of transit time. In addition, data from animal models and preliminary data from human trials suggest a role for the gut-brain axis in the mechanism of GES. This may involve alteration of secretion of hormones associated with hunger or satiety. Patient selection for gastric stimulation therapy seems to be an important determinant of the treatment’s outcome. Here, we review the current status, potential mechanisms of action, and possible future applications of gastric stimulation for obesity. PMID:22654422

  4. Modelling body weight, dieting and obesity traps

    Science.gov (United States)

    Barbieri, Paolo Nicola

    2017-02-01

    This paper presents a theoretical investigation into why losing weight is so difficult even in the absence of rational addiction, time-inconsistent preferences or bounded rationality. We add to the existing literature by focusing on the role that individual metabolism has on weight loss. The results from the theoretical model provide multiple steady states and a threshold revealing a situation of "obesity traps" that the individual must surpass in order to successfully lose weight. Any weight-loss efforts that the individual undertakes have to surpass such threshold in order to result in permanent weight loss, otherwise the individual will gradually regain weight and converge to his or her previous body weight.

  5. The Gender Weight Gap: Sons, Daughters, and Maternal Weight

    OpenAIRE

    Pham-Kanter, Genevieve

    2010-01-01

    Although the effect of parents on their children has been the focus of much research on health and families, the influence of children on their parents has not been well studied. In this paper, I examine the effect of the sex composition of children on mothers' physical condition, as proxied by their weight. Using two independent datasets, I find that, many years after the birth of their children, women who have first-born daughters weigh on average 2-6 pounds less than women who have first-b...

  6. Weight gain during pregnancy :the characteristics of women who experience excess weight gain /1990.

    OpenAIRE

    Ling, Carol Carlson

    1990-01-01

    Weight gain during pregnancy, relationships among body image, body weight standards, and attitudes toward weight gain were investigated. Weight gain recommendations, based on preconceptional weight status (PCWS) reflected current practices in prenatal care at Sentara Norfolk General Hospital, Norfolk, VA, and provided a basis on which to categorize weight gain as inadequate, appropriate, and excess. Women who experienced excess weight gain (EWG) were compared to those who ex...

  7. The bid to lose weight: impact of social media on weight perceptions, weight control and diabetes.

    Science.gov (United States)

    Das, Leah; Mohan, Ranjini; Makaya, Tafadzwa

    2014-01-01

    Over the last decade the internet has come to permeate every aspect of our lives. With huge leaps in accessibility of the internet via mobile personal devices such as smart cellular phones and tablets, individuals are connected to the internet virtually all the time. It is no surprise therefore that social media now dominates the lives of many people within society. The authors take a look at how social media is influencing diabetes with particular focus on weight perception, weight management and eating behaviours. The authors explore the concept of how the advertising of Size 0 models and photo-shopping of images which are easily available on line and via social media is causing an increase in the number of young people with distorted body images. This has led to an increased number of people resorting to sometimes drastic weight loss programmes. We focus on the bid for 'low-fat' consumption and highlight how this could actually be leading to an increased risk for developing diabetes or worsening the complications of diabetes. We also discuss the increase of eating disorder in diabetes related to this distorted body image.

  8. Cancer Cachexia: Beyond Weight Loss.

    Science.gov (United States)

    Bruggeman, Andrew R; Kamal, Arif H; LeBlanc, Thomas W; Ma, Joseph D; Baracos, Vickie E; Roeland, Eric J

    2016-11-01

    Cancer cachexia is a multifactorial syndrome characterized by skeletal muscle loss leading to progressive functional impairment. Despite the ubiquity of cachexia in clinical practice, prevention, early identification, and intervention remain challenging. The impact of cancer cachexia on quality of life, treatment-related toxicity, physical function, and mortality are well established; however, establishing a clinically meaningful definition has proven challenging because of the focus on weight loss alone. Attempts to more comprehensively define cachexia through body composition, physical functioning, and molecular biomarkers, while promising, are yet to be routinely incorporated into clinical practice. Pharmacologic agents that have not been approved by the US Food and Drug Administration but that are currently used in cancer cachexia (ie, megestrol, dronabinol) may improve weight but not outcomes of interest such as muscle mass, physical activity, or mortality. Their routine use is limited by adverse effects. For the practicing oncologist, early identification and management of cachexia is critical. Oncologists must recognize cachexia beyond weight loss alone, focusing instead on body composition and physical functioning. In fact, becoming emaciated is a late sign of cachexia that characterizes its refractory stage. Given that cachexia is a multifactorial syndrome, it requires early identification and polymodal intervention, including optimal cancer therapy, symptom management, nutrition, exercise, and psychosocial support. Consequently, oncologists have a role in ensuring that these resources are available to their patients. In addition, in light of the promising investigational agents, it remains imperative to refer patients with cachexia to clinical trials so that available options can be expanded to effectively treat this pervasive problem.

  9. [Fast food promotes weight gain].

    Science.gov (United States)

    Stender, Steen; Dyerberg, Jørn; Astrup, Arne V

    2007-05-07

    The total amounts of fat in a fast food menu consisting of French fries and fried Chicken Nuggets from McDonald's and KFC, respectively, bought in 35 different countries vary from 41 to 71 gram. In most countries the menu contained unacceptably high amounts of industrially-produced trans fat which contributes to an increased risk of ischaemic heart disease, weight gain, abdominal fat accumulation and type 2 diabetes. The quality of the ingredients in fast food ought to be better and the size of the portions smaller and less energy-dense so that frequent fast food meals do not increase the risk of obesity and diseases among customers.

  10. Moduli of weighted hyperplane arrangements

    CERN Document Server

    Lahoz, Martí; Macrí, Emanuele; Stellari, Paolo

    2015-01-01

    This book focuses on a large class of geometric objects in moduli theory and provides explicit computations to investigate their families. Concrete examples are developed that take advantage of the intricate interplay between Algebraic Geometry and Combinatorics. Compactifications of moduli spaces play a crucial role in Number Theory, String Theory, and Quantum Field Theory – to mention just a few. In particular, the notion of compactification of moduli spaces has been crucial for solving various open problems and long-standing conjectures. Further, the book reports on compactification techniques for moduli spaces in a large class where computations are possible, namely that of weighted stable hyperplane arrangements.

  11. Obesity Epidemic: Pharmaceutical Weight Loss.

    Science.gov (United States)

    Curry, Stephanie A

    2017-03-01

    Obesity is a chronic disease universally defined as an excess of adipose tissue resulting in body mass index (BMI) > 30.0 kg/m2. Over the past few years, the concept of prevention has gained increased awareness, thus leading to the development of additional pharmaceutical options for the treatment of obesity since 2012. Treating obesity revolves around an individualized, multi-disciplinary approach with additional focus on a healthy and supportive lifestyle to maintain the weight loss. [Full article available at http://rimed.org/rimedicaljournal-2017-03.asp].

  12. Gender Differences in Weight Loss: Evidence from a NHS Weight Management Service

    OpenAIRE

    BHOGAL, Manpal Singh; Langford, Robert

    2014-01-01

    Provides evidence that men lose more weight than women when enrolled on a weight loss intervention.\\ud •\\ud Men lose more weight than women from their initial assessment up to 12-months.\\ud •\\ud Men maintain their weight and continue to lose more weight postintervention compared to women.

  13. Concomitant changes in sleep duration and body weight and body composition during weight loss and 3-mo weight maintenance

    National Research Council Canada - National Science Library

    Verhoef, S.P; Camps, S.G; Gonnissen, H.K; Westerterp, K.R; Westerterp-Plantenga, M.S

    2013-01-01

    An inverse relation between sleep duration and body mass index (BMI) has been shown. We assessed the relation between changes in sleep duration and changes in body weight and body composition during weight loss...

  14. Weighted OFDM for wireless multipath channels

    DEFF Research Database (Denmark)

    Prasad, Ramjee; Nikookar, H.

    2000-01-01

    In this paper the novel method of "weighted OFDM" is addressed. Different types of weighting factors (including Rectangular, Bartlett, Gaussian. Raised cosine, Half-sin and Shanon) are considered. The impact of weighting of OFDM on the peak-to-average power ratio (PAPR) is investigated by means...... of simulation and is compared for the above mentioned weighting factors. Results show that by weighting of the OFDM signal the PAPR reduces. Bit error performance of weighted multicarrier transmission over a multipath channel is also investigated. Results indicate that there is a trade off between PAPR...

  15. Weight Watchers on prescription: An observational study of weight change among adults referred to Weight Watchers by the NHS

    OpenAIRE

    Ahern, Amy Louise; Olson, Ashley D; Aston, Louise M; Jebb, Susan A

    2011-01-01

    Abstract Background The scale of overweight and obesity in the UK places a considerable burden on the NHS. In some areas the NHS has formed partnerships with commercial companies to offer weight management services, but there has been little evaluation of these schemes. This study is an independent audit of the Weight Watchers NHS Referral scheme and evaluates the weight change of obese and overweight adults referred to Weight Watchers (WW) by the NHS. Method Data was obtained from the WW NHS...

  16. Pediatricians' weight assessment and obesity management practices

    Directory of Open Access Journals (Sweden)

    Galvan Kate

    2009-03-01

    Full Text Available Abstract Background Clinician adherence to obesity screening guidelines from United States health agencies remains suboptimal. This study explored how personal and career demographics influence pediatricians' weight assessment and management practices. Methods A web-based survey was distributed to U.S. pediatricians. Respondents were asked to identify the weight status of photographed children and about their weight assessment and management practices. Associations between career and personal demographic variables and pediatricians' weight perceptions, weight assessment and management practices were evaluated using univariate and multivariate modeling. Results 3,633 pediatric medical providers correctly identified the weight status of children at a median rate of 58%. The majority of pediatric clinicians were white, female, and of normal weight status with more than 10 years clinical experience. Experienced pediatric medical providers were less likely than younger colleagues to correctly identify the weight status of pictured children and were also less likely to know and use BMI criteria for assessing weight status. General pediatricians were more likely than subspecialty practitioners to provide diverse interventions for weight management. Non-white and Hispanic general practitioners were more likely than counterparts to consider cultural approaches to weight management. Conclusion Pediatricians' perceptions of children's weight and their weight assessment and management practices are influenced by career and personal characteristics. Objective criteria and clinical guidelines should be uniformly applied by pediatricians to screen for and manage pediatric obesity.

  17. Family support and weight-loss strategies among adolescents reporting sustained weight loss.

    Science.gov (United States)

    Utter, Jennifer; Denny, Simon; Dixon, Robyn; Ameratunga, Shanthi; Teevale, Tasileta

    2013-03-01

    The current research aims to describe the weight-control strategies and family support for young people reporting sustained weight loss in a large, population-based sample. Data were collected as part of Youth'07, a nationally representative survey of the health and well-being of New Zealand youth. New Zealand secondary schools, 2007. Secondary-school students (n 9107). Among young people who attempted weight loss in the previous year, 51% reported long-term weight loss (lost weight and maintained weight loss for 6 months). Students reporting long-term weight loss were more likely to be male, but did not differ by age, ethnicity, socio-economic deprivation or measured weight status from students who reported temporary/recent weight loss or no weight loss. Students with long-term weight loss also reported healthier weight-control strategies (e.g., exercising, eating fewer fatty foods, eating fewer sweets), high parental support for healthy eating/activity and were less likely to report being teased about their weight by their family and having junk food available at home than students with temporary/recent weight loss or no weight loss. Approximately 50% of young people attempting weight loss reported sustained weight loss. Young people who reported sustained weight loss appeared to have more family support than those who did not achieve this, suggesting the importance for weight-control services and interventions in adolescents of actively engaging the family.

  18. Healthy Weight: Healthy Weight Loss Starts With a Plan You Can Stick To

    Science.gov (United States)

    Skip Navigation Bar Home Current Issue Past Issues Healthy Weight Healthy Weight Loss Starts With a Plan You Can ... providers don't always address issues such as healthy eating, physical activity, and weight management during general ...

  19. Weight gain since menopause and its associations with weight loss maintenance in obese postmenopausal women.

    Science.gov (United States)

    Sénéchal, M; Arguin, H; Bouchard, D R; Carpentier, A C; Ardilouze, J L; Dionne, I J; Brochu, M

    2011-01-01

    To examine the association between weight gain since menopause and weight regain after a weight loss program. Participants were 19 obese women who participated in a 15-week weight loss program and a 12-month follow-up. Main outcomes were: body composition, resting metabolic rate, energy intake, energy expenditure, and weight regain at follow-up. All body composition measures significantly decreased after intervention (all P ≤ 0.01) while all measures of fatness increased significantly after the 12-month follow-up (P ≤ 0.01). Body weight gain since menopause was associated with body weight regain (r = 0.65; P = 0.003) after follow-up even after adjustment for confounders. Weight gain since menopause is associated with body weight regain following the weight loss program. Therefore, weight gain since menopause should be considered as a factor influencing weight loss maintenance in older women.

  20. Therapy and Weight Management (For Teens)

    Science.gov (United States)

    ... to talk yourself out of your plan! Ways Counseling Helps You Stay on Track Weight-management therapists and ... the blocks and obstacles you face. Weight-management counseling can help you recognize the things that make it difficult ...

  1. Can Beta Blockers Cause Weight Gain?

    Science.gov (United States)

    Beta blockers: Do they cause weight gain? Can beta blockers cause weight gain? Answers from Sheldon G. Sheps, ... can occur as a side effect of some beta blockers, especially the older ones, such as atenolol (Tenormin) ...

  2. Weight Loss: Ready to Change Your Habits?

    Science.gov (United States)

    ... the challenge of overhauling your eating and exercise habits. Instead, consider giving your life a chance to calm down before you launch your weight-loss program. Achieving and maintaining a healthy weight is a lifelong process. Start by making ...

  3. Weight Loss Surgery: An Option for Teens?

    Science.gov (United States)

    ... Vaccine Preventable Diseases Healthy Children > Health Issues > Conditions > Obesity > Weight Loss Surgery: An Option for Teens? Health Issues Listen ... for extremely overweight adolescents for whom more conservative weight loss ... obesity-related medical conditions such as high blood pressure , ...

  4. Physical Activity for a Healthy Weight

    Science.gov (United States)

    ... Weight Breastfeeding Micronutrient Malnutrition State and Local Programs Physical Activity for a Healthy Weight Language: English Español (Spanish) ... calories are used in typical activities? Why is physical activity important? Regular physical activity is important for good ...

  5. Weighing Portions Adds Up to Weight Loss

    Science.gov (United States)

    ... fullstory_167159.html Weighing Portions Adds Up to Weight Loss Put an end to guesstimating calories with simple ... control is a must when you want to lose weight. "Guesstimating" the size of a chicken breast at ...

  6. Wisconsin truck size and weight study.

    Science.gov (United States)

    2009-06-01

    2007 AB 238 requires the Department of Transportation to conduct a comprehensive study to review the system of : motor vehicle weight limits on Wisconsin's highways and bridges. Laws regarding allowable weight limits, lengths, and : widths of commerc...

  7. Obesity and weight management at menopause.

    Science.gov (United States)

    Proietto, Joseph

    2017-06-01

    Many women report gaining weight as they transition through menopause. For most, the weight gain is modest and can be reduced with a conscious effort to limit energy intake and increase energy expenditure. However, many women who are already overweight and obese will gain more weight as they approach menopause. The aims of this paper are to explain the reasons for menopausal weight gain and to detail a method for achieving and sustaining a substantial weight loss. Weight gain during menopause is predominantly due to a reduction in spontaneous activity. For women who are lean, advice about controlling energy intake and increasing physical activity may be all that is required to prevent weight gain. For women who are overweight and obese rapid weight loss is best achieved with the help of a very low energy diet. This must be followed by lifelong behaviour modification with or without the help of hunger-suppressing pharmacotherapy.

  8. Disease Human - MDC_LowBirthWeight

    Data.gov (United States)

    NSGIC Local Govt | GIS Inventory — Polygon feature class based on Zip Code boundaries showing the percentage of babies born in Miami-Dade County in 2006 with low birth weights. Low birth weight is...

  9. Oral Lactobacillus Counts Predict Weight Gain Susceptibility

    DEFF Research Database (Denmark)

    Rosing, Johanne Aviaja; Walker, Karen Christina; Jensen, Benjamin A. H.

    2017-01-01

    Background: Recent studies have shown an association between weight change and the makeup of the intestinal microbiota in humans. Specifically, Lactobacillus, a part of the entire gastrointestinal tract's microbiota, has been shown to contribute to weight regulation. Aim: We examined...

  10. Osteoarthritis, obesity and weight loss

    DEFF Research Database (Denmark)

    Bliddal, Henning; Leeds, A R; Christensen, Robin Daniel Kjersgaard

    2014-01-01

    Obesity is widely acknowledged as a risk factor for both the incidence and progression of osteoarthritis, and has a negative influence on outcomes. Loss of at least 10% of body weight, coupled with exercise, is recognized as a cornerstone in the management of obese patients with osteoarthritis......, and can lead to significant improvement in symptoms, pain relief, physical function and health-related quality of life. However, questions still remain surrounding optimal management. Given the significant health, social and economic burden of osteoarthritis, especially in obese patients, it is imperative...... to advance our knowledge of osteoarthritis and obesity, and apply this to improving care and outcomes. This paper overviews what is already known about osteoarthritis and obesity, discusses current key challenges and ongoing hypotheses arising from research in these areas, and finally, postulates what...

  11. The daily weight gain, growth rate and length-weight relationships of ...

    African Journals Online (AJOL)

    The daily weight gain, growth rate and length-weight relationships of Clarias gariepinus, Heterobranchus longifilis and their reciprocal hybrids (Pisces: Clariidae) reared under ambient environmental conditions.

  12. How Can I Lose Weight Safely?

    Science.gov (United States)

    ... Abuse Love and Romance Understanding Other People How Can I Lose Weight Safely? KidsHealth > For Teens > How Can I Lose Weight Safely? Print A A A ... to talk to a doctor or dietitian, who can compare your weight with healthy norms to help ...

  13. Nuttall Oak Volume and Weight Tables

    Science.gov (United States)

    Bryce E. Schlaegel; Regan B. Willson

    1983-01-01

    Volume and weight tables were constructed from a 62-tree sample of Nuttall oak (Quercus nuttallii Palmer) taken in the Mississippi Delta. The tables present volume, green weight, and dry weight of bole wood, bole wood plus bark, and total tree above a one-foot stump as predicted from the nonlinear model Y = 0Db

  14. 38 CFR 4.112 - Weight loss.

    Science.gov (United States)

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2010-07-01 2010-07-01 false Weight loss. 4.112... DISABILITIES Disability Ratings The Digestive System § 4.112 Weight loss. For purposes of evaluating conditions in § 4.114, the term “substantial weight loss” means a loss of greater than 20 percent of the...

  15. Maternal Weight Gain Biosocial Characteristics And Perinatal ...

    African Journals Online (AJOL)

    Two perinatal deaths occurred, with a perinatal mortality rate of 9.52/ 1000.Their mother's weight gains were not attributable to the deaths. Conclusion The study has shown that parity and social class significantly affect maternal weight gain in pregnancy. Even though the mean weight gain in this study was 8.58 ± 3.61kg, ...

  16. The Weight of Iron and Feathers

    Science.gov (United States)

    Zendri, G.; Gratton, L. M.; Oss, S.

    2014-01-01

    We discuss the popular question concerning the difference in weight between 1 kg of iron and 1 kg of feathers, by taking into account the non-trivial aspect of the semantic interpretation of "weight" and the weighting procedure. The inclusion of air buoyancy makes the correct answer an interesting one. We describe and comment on the…

  17. Biased trapping issue on weighted hierarchical networks

    Indian Academy of Sciences (India)

    In this paper, we present trapping issues of weight-dependent walks on weighted hierarchical networks which are based on the classic scale-free hierarchical networks. Assuming that edge's weight is used as local information by a random walker, we introduce a biased walk. The biased walk is that a walker, at each step, ...

  18. Benefit of Doubt Approach to Case Weighting

    DEFF Research Database (Denmark)

    Wittrup, Jesper; Bogetoft, Peter

    The implementation of an efficient and reliable case weighting system (CWS) is currently considered essential for running an efficient judiciary. However, traditional models for establishing case weights are time-consuming and expensive. Furthermore, since such case weights are often viewed as in...

  19. Path Minima Queries in Dynamic Weighted Trees

    DEFF Research Database (Denmark)

    Davoodi, Pooya; Brodal, Gerth Stølting; Satti, Srinivasa Rao

    2011-01-01

    In the path minima problem on a tree, each edge is assigned a weight and a query asks for the edge with minimum weight on a path between two nodes. For the dynamic version of the problem, where the edge weights can be updated, we give data structures that achieve optimal query time\\todo{what about...

  20. 23 CFR 658.17 - Weight.

    Science.gov (United States)

    2010-04-01

    ... 23 Highways 1 2010-04-01 2010-04-01 false Weight. 658.17 Section 658.17 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS TRUCK SIZE AND WEIGHT, ROUTE... agency transit passenger bus, is excluded from the axle weight limits in paragraphs (c) through (e) of...